2024-06-10 22:57:32

by Charlie Jenkins

[permalink] [raw]
Subject: [PATCH v2 00/13] riscv: Add support for xtheadvector

xtheadvector is a custom extension that is based upon riscv vector
version 0.7.1 [1]. All of the vector routines have been modified to
support this alternative vector version based upon whether xtheadvector
was determined to be supported at boot.

vlenb is not supported on the existing xtheadvector hardware, so a
devicetree property thead,vlenb is added to provide the vlenb to Linux.

There is a new hwprobe key RISCV_HWPROBE_KEY_VENDOR_EXT_THEAD_0 that is
used to request which thead vendor extensions are supported on the
current platform. This allows future vendors to allocate hwprobe keys
for their vendor.

Support for xtheadvector is also added to the vector kselftests.

Signed-off-by: Charlie Jenkins <[email protected]>

[1] https://github.com/T-head-Semi/thead-extension-spec/blob/95358cb2cca9489361c61d335e03d3134b14133f/xtheadvector.adoc

---
This series is a continuation of a different series that was fragmented
into two other series in an attempt to get part of it merged in the 6.10
merge window. The split-off series did not get merged due to a NAK on
the series that added the generic riscv,vlenb devicetree entry. This
series has converted riscv,vlenb to thead,vlenb to remedy this issue.

The original series is titled "riscv: Support vendor extensions and
xtheadvector" [3].

The series titled "riscv: Extend cpufeature.c to detect vendor
extensions" is still under development and this series is based on that
series! [4]

I have tested this with an Allwinner Nezha board. I ran into issues
booting the board after 6.9-rc1 so I applied these patches to 6.8. There
are a couple of minor merge conflicts that do arrise when doing that, so
please let me know if you have been able to boot this board with a 6.9
kernel. I used SkiffOS [1] to manage building the image, but upgraded
the U-Boot version to Samuel Holland's more up-to-date version [2] and
changed out the device tree used by U-Boot with the device trees that
are present in upstream linux and this series. Thank you Samuel for all
of the work you did to make this task possible.

[1] https://github.com/skiffos/SkiffOS/tree/master/configs/allwinner/nezha
[2] https://github.com/smaeul/u-boot/commit/2e89b706f5c956a70c989cd31665f1429e9a0b48
[3] https://lore.kernel.org/all/20240503-dev-charlie-support_thead_vector_6_9-v6-0-cb7624e65d82@rivosinc.com/
[4] https://lore.kernel.org/linux-riscv/20240609-support_vendor_extensions-v2-0-9a43f1fdcbb9@rivosinc.com/

---
Changes in v2:
- Removed extraneous references to "riscv,vlenb" (Jess)
- Moved declaration of "thead,vlenb" into cpus.yaml and added
restriction that it's only applicable to thead cores (Conor)
- Check CONFIG_RISCV_ISA_XTHEADVECTOR instead of CONFIG_RISCV_ISA_V for
thead,vlenb (Jess)
- Fix naming of hwprobe variables (Evan)
- Link to v1: https://lore.kernel.org/r/[email protected]

---
Charlie Jenkins (12):
dt-bindings: riscv: Add xtheadvector ISA extension description
dt-bindings: cpus: add a thead vlen register length property
riscv: dts: allwinner: Add xtheadvector to the D1/D1s devicetree
riscv: Add thead and xtheadvector as a vendor extension
riscv: vector: Use vlenb from DT for thead
riscv: csr: Add CSR encodings for VCSR_VXRM/VCSR_VXSAT
riscv: Add xtheadvector instruction definitions
riscv: vector: Support xtheadvector save/restore
riscv: hwprobe: Add thead vendor extension probing
riscv: hwprobe: Document thead vendor extensions and xtheadvector extension
selftests: riscv: Fix vector tests
selftests: riscv: Support xtheadvector in vector tests

Heiko Stuebner (1):
RISC-V: define the elements of the VCSR vector CSR

Documentation/arch/riscv/hwprobe.rst | 10 +
Documentation/devicetree/bindings/riscv/cpus.yaml | 19 ++
.../devicetree/bindings/riscv/extensions.yaml | 10 +
arch/riscv/Kconfig.vendor | 26 ++
arch/riscv/boot/dts/allwinner/sun20i-d1s.dtsi | 3 +-
arch/riscv/include/asm/cpufeature.h | 2 +
arch/riscv/include/asm/csr.h | 13 +
arch/riscv/include/asm/hwprobe.h | 4 +-
arch/riscv/include/asm/switch_to.h | 2 +-
arch/riscv/include/asm/vector.h | 249 +++++++++++++----
arch/riscv/include/asm/vendor_extensions/thead.h | 42 +++
.../include/asm/vendor_extensions/thead_hwprobe.h | 18 ++
.../include/asm/vendor_extensions/vendor_hwprobe.h | 37 +++
arch/riscv/include/uapi/asm/hwprobe.h | 3 +-
arch/riscv/include/uapi/asm/vendor/thead.h | 3 +
arch/riscv/kernel/cpufeature.c | 51 +++-
arch/riscv/kernel/kernel_mode_vector.c | 8 +-
arch/riscv/kernel/process.c | 4 +-
arch/riscv/kernel/signal.c | 6 +-
arch/riscv/kernel/sys_hwprobe.c | 5 +
arch/riscv/kernel/vector.c | 25 +-
arch/riscv/kernel/vendor_extensions.c | 10 +
arch/riscv/kernel/vendor_extensions/Makefile | 2 +
arch/riscv/kernel/vendor_extensions/thead.c | 18 ++
.../riscv/kernel/vendor_extensions/thead_hwprobe.c | 19 ++
tools/testing/selftests/riscv/vector/.gitignore | 3 +-
tools/testing/selftests/riscv/vector/Makefile | 17 +-
.../selftests/riscv/vector/v_exec_initval_nolibc.c | 93 +++++++
tools/testing/selftests/riscv/vector/v_helpers.c | 67 +++++
tools/testing/selftests/riscv/vector/v_helpers.h | 7 +
tools/testing/selftests/riscv/vector/v_initval.c | 22 ++
.../selftests/riscv/vector/v_initval_nolibc.c | 68 -----
.../selftests/riscv/vector/vstate_exec_nolibc.c | 20 +-
.../testing/selftests/riscv/vector/vstate_prctl.c | 295 ++++++++++++---------
34 files changed, 910 insertions(+), 271 deletions(-)
---
base-commit: 11cc01d4d2af304b7288251aad7e03315db8dffc
change-id: 20240530-xtheadvector-833d3d17b423
--
- Charlie



2024-06-10 22:57:57

by Charlie Jenkins

[permalink] [raw]
Subject: [PATCH v2 02/13] dt-bindings: cpus: add a thead vlen register length property

Add a property analogous to the vlenb CSR so that software can detect
the vector length of each CPU prior to it being brought online.
Currently software has to assume that the vector length read from the
boot CPU applies to all possible CPUs. On T-Head CPUs implementing
pre-ratification vector, reading the th.vlenb CSR may produce an illegal
instruction trap, so this property is required on such systems.

Signed-off-by: Charlie Jenkins <[email protected]>
---
Documentation/devicetree/bindings/riscv/cpus.yaml | 19 +++++++++++++++++++
1 file changed, 19 insertions(+)

diff --git a/Documentation/devicetree/bindings/riscv/cpus.yaml b/Documentation/devicetree/bindings/riscv/cpus.yaml
index d87dd50f1a4b..a6bbbf658977 100644
--- a/Documentation/devicetree/bindings/riscv/cpus.yaml
+++ b/Documentation/devicetree/bindings/riscv/cpus.yaml
@@ -26,6 +26,18 @@ description: |
allOf:
- $ref: /schemas/cpu.yaml#
- $ref: extensions.yaml
+ - if:
+ not:
+ properties:
+ compatible:
+ contains:
+ enum:
+ - thead,c906
+ - thead,c910
+ - thead,c920
+ then:
+ properties:
+ thead,vlenb: false

properties:
compatible:
@@ -94,6 +106,13 @@ properties:
description:
The blocksize in bytes for the Zicboz cache operations.

+ thead,vlenb:
+ $ref: /schemas/types.yaml#/definitions/uint32
+ description:
+ VLEN/8, the vector register length in bytes. This property is required on
+ thead systems where the vector register length is not identical on all harts, or
+ the vlenb CSR is not available.
+
# RISC-V has multiple properties for cache op block sizes as the sizes
# differ between individual CBO extensions
cache-op-block-size: false

--
2.44.0


2024-06-10 22:58:40

by Charlie Jenkins

[permalink] [raw]
Subject: [PATCH v2 05/13] riscv: vector: Use vlenb from DT for thead

If thead,vlenb is provided in the device tree, prefer that over reading
the vlenb csr.

Signed-off-by: Charlie Jenkins <[email protected]>
---
arch/riscv/Kconfig.vendor | 13 ++++++++++
arch/riscv/include/asm/cpufeature.h | 2 ++
arch/riscv/kernel/cpufeature.c | 48 +++++++++++++++++++++++++++++++++++++
arch/riscv/kernel/vector.c | 12 +++++++++-
4 files changed, 74 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/Kconfig.vendor b/arch/riscv/Kconfig.vendor
index 9897442bd44f..b096548fe0ff 100644
--- a/arch/riscv/Kconfig.vendor
+++ b/arch/riscv/Kconfig.vendor
@@ -26,6 +26,19 @@ config RISCV_ISA_VENDOR_EXT_THEAD
extensions. Without this option enabled, T-Head vendor extensions will
not be detected at boot and their presence not reported to userspace.

+ If you don't know what to do here, say Y.
+
+config RISCV_ISA_XTHEADVECTOR
+ bool "xtheadvector extension support"
+ depends on RISCV_ISA_VENDOR_EXT_THEAD
+ depends on RISCV_ISA_V
+ depends on FPU
+ default y
+ help
+ Say N here if you want to disable all xtheadvector related procedures
+ in the kernel. This will disable vector for any T-Head board that
+ contains xtheadvector rather than the standard vector.
+
If you don't know what to do here, say Y.
endmenu

diff --git a/arch/riscv/include/asm/cpufeature.h b/arch/riscv/include/asm/cpufeature.h
index b029ca72cebc..e0a3164c7a06 100644
--- a/arch/riscv/include/asm/cpufeature.h
+++ b/arch/riscv/include/asm/cpufeature.h
@@ -31,6 +31,8 @@ DECLARE_PER_CPU(struct riscv_cpuinfo, riscv_cpuinfo);
/* Per-cpu ISA extensions. */
extern struct riscv_isainfo hart_isa[NR_CPUS];

+extern u32 thead_vlenb_of;
+
void riscv_user_isa_enable(void);

#define _RISCV_ISA_EXT_DATA(_name, _id, _subset_exts, _subset_exts_size) { \
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index 2107c59575dd..077be4ab1f9a 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -37,6 +37,8 @@ static DECLARE_BITMAP(riscv_isa, RISCV_ISA_EXT_MAX) __read_mostly;
/* Per-cpu ISA extensions. */
struct riscv_isainfo hart_isa[NR_CPUS];

+u32 thead_vlenb_of;
+
/**
* riscv_isa_extension_base() - Get base extension word
*
@@ -625,6 +627,46 @@ static void __init riscv_fill_vendor_ext_list(int cpu)
}
}

+static int has_thead_homogeneous_vlenb(void)
+{
+ int cpu;
+ u32 prev_vlenb = 0;
+ u32 vlenb;
+
+ /* Ignore thead,vlenb property if xtheavector is not enabled in the kernel */
+ if (!IS_ENABLED(CONFIG_RISCV_ISA_XTHEADVECTOR))
+ return 0;
+
+ for_each_possible_cpu(cpu) {
+ struct device_node *cpu_node;
+
+ cpu_node = of_cpu_device_node_get(cpu);
+ if (!cpu_node) {
+ pr_warn("Unable to find cpu node\n");
+ return -ENOENT;
+ }
+
+ if (of_property_read_u32(cpu_node, "thead,vlenb", &vlenb)) {
+ of_node_put(cpu_node);
+
+ if (prev_vlenb)
+ return -ENOENT;
+ continue;
+ }
+
+ if (prev_vlenb && vlenb != prev_vlenb) {
+ of_node_put(cpu_node);
+ return -ENOENT;
+ }
+
+ prev_vlenb = vlenb;
+ of_node_put(cpu_node);
+ }
+
+ thead_vlenb_of = vlenb;
+ return 0;
+}
+
static int __init riscv_fill_hwcap_from_ext_list(unsigned long *isa2hwcap)
{
unsigned int cpu;
@@ -689,6 +731,12 @@ static int __init riscv_fill_hwcap_from_ext_list(unsigned long *isa2hwcap)
riscv_fill_vendor_ext_list(cpu);
}

+ if (riscv_isa_vendor_extension_available(THEAD_VENDOR_ID, XTHEADVECTOR) &&
+ has_thead_homogeneous_vlenb() < 0) {
+ pr_warn("Unsupported heterogeneous vlenb detected, vector extension disabled.\n");
+ elf_hwcap &= ~COMPAT_HWCAP_ISA_V;
+ }
+
if (bitmap_empty(riscv_isa, RISCV_ISA_EXT_MAX))
return -ENOENT;

diff --git a/arch/riscv/kernel/vector.c b/arch/riscv/kernel/vector.c
index 6727d1d3b8f2..3ba2f2432483 100644
--- a/arch/riscv/kernel/vector.c
+++ b/arch/riscv/kernel/vector.c
@@ -33,7 +33,17 @@ int riscv_v_setup_vsize(void)
{
unsigned long this_vsize;

- /* There are 32 vector registers with vlenb length. */
+ /*
+ * There are 32 vector registers with vlenb length.
+ *
+ * If the thead,vlenb property was provided by the firmware, use that
+ * instead of probing the CSRs.
+ */
+ if (thead_vlenb_of) {
+ this_vsize = thead_vlenb_of * 32;
+ return 0;
+ }
+
riscv_v_enable();
this_vsize = csr_read(CSR_VLENB) * 32;
riscv_v_disable();

--
2.44.0


2024-06-10 22:58:55

by Charlie Jenkins

[permalink] [raw]
Subject: [PATCH v2 06/13] RISC-V: define the elements of the VCSR vector CSR

From: Heiko Stuebner <[email protected]>

The VCSR CSR contains two elements VXRM[2:1] and VXSAT[0].

Define constants for those to access the elements in a readable way.

Acked-by: Guo Ren <[email protected]>
Reviewed-by: Conor Dooley <[email protected]>
Signed-off-by: Heiko Stuebner <[email protected]>
Signed-off-by: Charlie Jenkins <[email protected]>
---
arch/riscv/include/asm/csr.h | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/arch/riscv/include/asm/csr.h b/arch/riscv/include/asm/csr.h
index 25966995da04..18e178d83401 100644
--- a/arch/riscv/include/asm/csr.h
+++ b/arch/riscv/include/asm/csr.h
@@ -216,6 +216,11 @@
#define SMSTATEEN0_SSTATEEN0_SHIFT 63
#define SMSTATEEN0_SSTATEEN0 (_ULL(1) << SMSTATEEN0_SSTATEEN0_SHIFT)

+/* VCSR flags */
+#define VCSR_VXRM_MASK 3
+#define VCSR_VXRM_SHIFT 1
+#define VCSR_VXSAT_MASK 1
+
/* symbolic CSR names: */
#define CSR_CYCLE 0xc00
#define CSR_TIME 0xc01

--
2.44.0


2024-06-10 22:59:14

by Charlie Jenkins

[permalink] [raw]
Subject: [PATCH v2 07/13] riscv: csr: Add CSR encodings for VCSR_VXRM/VCSR_VXSAT

The VXRM vector csr for xtheadvector has an encoding of 0xa and VXSAT
has an encoding of 0x9.

Co-developed-by: Heiko Stuebner <[email protected]>
Signed-off-by: Charlie Jenkins <[email protected]>
---
arch/riscv/include/asm/csr.h | 2 ++
1 file changed, 2 insertions(+)

diff --git a/arch/riscv/include/asm/csr.h b/arch/riscv/include/asm/csr.h
index 18e178d83401..9086639a3dde 100644
--- a/arch/riscv/include/asm/csr.h
+++ b/arch/riscv/include/asm/csr.h
@@ -220,6 +220,8 @@
#define VCSR_VXRM_MASK 3
#define VCSR_VXRM_SHIFT 1
#define VCSR_VXSAT_MASK 1
+#define VCSR_VXSAT 0x9
+#define VCSR_VXRM 0xa

/* symbolic CSR names: */
#define CSR_CYCLE 0xc00

--
2.44.0


2024-06-10 22:59:26

by Charlie Jenkins

[permalink] [raw]
Subject: [PATCH v2 08/13] riscv: Add xtheadvector instruction definitions

xtheadvector uses different encodings than standard vector for
vsetvli and vector loads/stores. Write the instruction formats to be
used in assembly code.

Co-developed-by: Heiko Stuebner <[email protected]>
Signed-off-by: Charlie Jenkins <[email protected]>
---
arch/riscv/include/asm/vendor_extensions/thead.h | 26 ++++++++++++++++++++++++
1 file changed, 26 insertions(+)

diff --git a/arch/riscv/include/asm/vendor_extensions/thead.h b/arch/riscv/include/asm/vendor_extensions/thead.h
index 48421d1553ad..27a253a20ab8 100644
--- a/arch/riscv/include/asm/vendor_extensions/thead.h
+++ b/arch/riscv/include/asm/vendor_extensions/thead.h
@@ -13,4 +13,30 @@

extern struct riscv_isa_vendor_ext_data_list riscv_isa_vendor_ext_list_thead;

+/* Extension specific helpers */
+
+/*
+ * Vector 0.7.1 as used for example on T-Head Xuantie cores, uses an older
+ * encoding for vsetvli (ta, ma vs. d1), so provide an instruction for
+ * vsetvli t4, x0, e8, m8, d1
+ */
+#define THEAD_VSETVLI_T4X0E8M8D1 ".long 0x00307ed7\n\t"
+#define THEAD_VSETVLI_X0X0E8M8D1 ".long 0x00307057\n\t"
+
+/*
+ * While in theory, the vector-0.7.1 vsb.v and vlb.v result in the same
+ * encoding as the standard vse8.v and vle8.v, compilers seem to optimize
+ * the call resulting in a different encoding and then using a value for
+ * the "mop" field that is not part of vector-0.7.1
+ * So encode specific variants for vstate_save and _restore.
+ */
+#define THEAD_VSB_V_V0T0 ".long 0x02028027\n\t"
+#define THEAD_VSB_V_V8T0 ".long 0x02028427\n\t"
+#define THEAD_VSB_V_V16T0 ".long 0x02028827\n\t"
+#define THEAD_VSB_V_V24T0 ".long 0x02028c27\n\t"
+#define THEAD_VLB_V_V0T0 ".long 0x012028007\n\t"
+#define THEAD_VLB_V_V8T0 ".long 0x012028407\n\t"
+#define THEAD_VLB_V_V16T0 ".long 0x012028807\n\t"
+#define THEAD_VLB_V_V24T0 ".long 0x012028c07\n\t"
+
#endif

--
2.44.0


2024-06-10 22:59:28

by Charlie Jenkins

[permalink] [raw]
Subject: [PATCH v2 03/13] riscv: dts: allwinner: Add xtheadvector to the D1/D1s devicetree

The D1/D1s SoCs support xtheadvector so it can be included in the
devicetree. Also include vlenb for the cpu.

Signed-off-by: Charlie Jenkins <[email protected]>
---
arch/riscv/boot/dts/allwinner/sun20i-d1s.dtsi | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/arch/riscv/boot/dts/allwinner/sun20i-d1s.dtsi b/arch/riscv/boot/dts/allwinner/sun20i-d1s.dtsi
index 64c3c2e6cbe0..6367112e614a 100644
--- a/arch/riscv/boot/dts/allwinner/sun20i-d1s.dtsi
+++ b/arch/riscv/boot/dts/allwinner/sun20i-d1s.dtsi
@@ -27,7 +27,8 @@ cpu0: cpu@0 {
riscv,isa = "rv64imafdc";
riscv,isa-base = "rv64i";
riscv,isa-extensions = "i", "m", "a", "f", "d", "c", "zicntr", "zicsr",
- "zifencei", "zihpm";
+ "zifencei", "zihpm", "xtheadvector";
+ thead,vlenb = <128>;
#cooling-cells = <2>;

cpu0_intc: interrupt-controller {

--
2.44.0


2024-06-10 22:59:57

by Charlie Jenkins

[permalink] [raw]
Subject: [PATCH v2 04/13] riscv: Add thead and xtheadvector as a vendor extension

Add support to the kernel for THead vendor extensions with the target of
the new extension xtheadvector.

Signed-off-by: Charlie Jenkins <[email protected]>
---
arch/riscv/Kconfig.vendor | 13 +++++++++++++
arch/riscv/include/asm/vendor_extensions/thead.h | 16 ++++++++++++++++
arch/riscv/kernel/cpufeature.c | 1 +
arch/riscv/kernel/vendor_extensions.c | 10 ++++++++++
arch/riscv/kernel/vendor_extensions/Makefile | 1 +
arch/riscv/kernel/vendor_extensions/thead.c | 18 ++++++++++++++++++
6 files changed, 59 insertions(+)

diff --git a/arch/riscv/Kconfig.vendor b/arch/riscv/Kconfig.vendor
index 6f1cdd32ed29..9897442bd44f 100644
--- a/arch/riscv/Kconfig.vendor
+++ b/arch/riscv/Kconfig.vendor
@@ -16,4 +16,17 @@ config RISCV_ISA_VENDOR_EXT_ANDES
If you don't know what to do here, say Y.
endmenu

+menu "T-Head"
+config RISCV_ISA_VENDOR_EXT_THEAD
+ bool "T-Head vendor extension support"
+ select RISCV_ISA_VENDOR_EXT
+ default y
+ help
+ Say N here to disable detection of and support for all T-Head vendor
+ extensions. Without this option enabled, T-Head vendor extensions will
+ not be detected at boot and their presence not reported to userspace.
+
+ If you don't know what to do here, say Y.
+endmenu
+
endmenu
diff --git a/arch/riscv/include/asm/vendor_extensions/thead.h b/arch/riscv/include/asm/vendor_extensions/thead.h
new file mode 100644
index 000000000000..48421d1553ad
--- /dev/null
+++ b/arch/riscv/include/asm/vendor_extensions/thead.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_RISCV_VENDOR_EXTENSIONS_THEAD_H
+#define _ASM_RISCV_VENDOR_EXTENSIONS_THEAD_H
+
+#include <asm/vendor_extensions.h>
+
+#include <linux/types.h>
+
+/*
+ * Extension keys must be strictly less than RISCV_ISA_VENDOR_EXT_MAX.
+ */
+#define RISCV_ISA_VENDOR_EXT_XTHEADVECTOR 0
+
+extern struct riscv_isa_vendor_ext_data_list riscv_isa_vendor_ext_list_thead;
+
+#endif
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index f2c24820700b..2107c59575dd 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -25,6 +25,7 @@
#include <asm/sbi.h>
#include <asm/vector.h>
#include <asm/vendor_extensions.h>
+#include <asm/vendor_extensions/thead.h>

#define NUM_ALPHA_EXTS ('z' - 'a' + 1)

diff --git a/arch/riscv/kernel/vendor_extensions.c b/arch/riscv/kernel/vendor_extensions.c
index b6c1e7b5d34b..662ba64a8f93 100644
--- a/arch/riscv/kernel/vendor_extensions.c
+++ b/arch/riscv/kernel/vendor_extensions.c
@@ -6,6 +6,7 @@
#include <asm/vendorid_list.h>
#include <asm/vendor_extensions.h>
#include <asm/vendor_extensions/andes.h>
+#include <asm/vendor_extensions/thead.h>

#include <linux/array_size.h>
#include <linux/types.h>
@@ -14,6 +15,9 @@ struct riscv_isa_vendor_ext_data_list *riscv_isa_vendor_ext_list[] = {
#ifdef CONFIG_RISCV_ISA_VENDOR_EXT_ANDES
&riscv_isa_vendor_ext_list_andes,
#endif
+#ifdef CONFIG_RISCV_ISA_VENDOR_EXT_THEAD
+ &riscv_isa_vendor_ext_list_thead,
+#endif
};

const size_t riscv_isa_vendor_ext_list_size = ARRAY_SIZE(riscv_isa_vendor_ext_list);
@@ -41,6 +45,12 @@ bool __riscv_isa_vendor_extension_available(int cpu, unsigned long vendor, unsig
cpu_bmap = &riscv_isa_vendor_ext_list_andes.per_hart_isa_bitmap[cpu];
break;
#endif
+ #ifdef CONFIG_RISCV_ISA_VENDOR_EXT_THEAD
+ case THEAD_VENDOR_ID:
+ bmap = &riscv_isa_vendor_ext_list_thead.all_harts_isa_bitmap;
+ cpu_bmap = &riscv_isa_vendor_ext_list_thead.per_hart_isa_bitmap[cpu];
+ break;
+ #endif
default:
return false;
}
diff --git a/arch/riscv/kernel/vendor_extensions/Makefile b/arch/riscv/kernel/vendor_extensions/Makefile
index 6a61aed944f1..353522cb3bf0 100644
--- a/arch/riscv/kernel/vendor_extensions/Makefile
+++ b/arch/riscv/kernel/vendor_extensions/Makefile
@@ -1,3 +1,4 @@
# SPDX-License-Identifier: GPL-2.0-only

obj-$(CONFIG_RISCV_ISA_VENDOR_EXT_ANDES) += andes.o
+obj-$(CONFIG_RISCV_ISA_VENDOR_EXT_THEAD) += thead.o
diff --git a/arch/riscv/kernel/vendor_extensions/thead.c b/arch/riscv/kernel/vendor_extensions/thead.c
new file mode 100644
index 000000000000..0934a2086473
--- /dev/null
+++ b/arch/riscv/kernel/vendor_extensions/thead.c
@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <asm/cpufeature.h>
+#include <asm/vendor_extensions.h>
+#include <asm/vendor_extensions/thead.h>
+
+#include <linux/array_size.h>
+#include <linux/types.h>
+
+/* All T-Head vendor extensions supported in Linux */
+const struct riscv_isa_ext_data riscv_isa_vendor_ext_thead[] = {
+ __RISCV_ISA_EXT_DATA(xtheadvector, RISCV_ISA_VENDOR_EXT_XTHEADVECTOR),
+};
+
+struct riscv_isa_vendor_ext_data_list riscv_isa_vendor_ext_list_thead = {
+ .ext_data_count = ARRAY_SIZE(riscv_isa_vendor_ext_thead),
+ .ext_data = riscv_isa_vendor_ext_thead,
+};

--
2.44.0


2024-06-10 23:00:24

by Charlie Jenkins

[permalink] [raw]
Subject: [PATCH v2 13/13] selftests: riscv: Support xtheadvector in vector tests

Extend existing vector tests to be compatible with the xtheadvector
instructions.

Signed-off-by: Charlie Jenkins <[email protected]>
---
.../selftests/riscv/vector/v_exec_initval_nolibc.c | 23 ++++--
tools/testing/selftests/riscv/vector/v_helpers.c | 17 +++-
tools/testing/selftests/riscv/vector/v_helpers.h | 4 +-
tools/testing/selftests/riscv/vector/v_initval.c | 12 ++-
.../selftests/riscv/vector/vstate_exec_nolibc.c | 20 +++--
.../testing/selftests/riscv/vector/vstate_prctl.c | 91 ++++++++++++++--------
6 files changed, 115 insertions(+), 52 deletions(-)

diff --git a/tools/testing/selftests/riscv/vector/v_exec_initval_nolibc.c b/tools/testing/selftests/riscv/vector/v_exec_initval_nolibc.c
index 74b13806baf0..58c29ea91b80 100644
--- a/tools/testing/selftests/riscv/vector/v_exec_initval_nolibc.c
+++ b/tools/testing/selftests/riscv/vector/v_exec_initval_nolibc.c
@@ -18,13 +18,22 @@ int main(int argc, char **argv)
unsigned long vl;
int first = 1;

- asm volatile (
- ".option push\n\t"
- ".option arch, +v\n\t"
- "vsetvli %[vl], x0, e8, m1, ta, ma\n\t"
- ".option pop\n\t"
- : [vl] "=r" (vl)
- );
+ if (argc > 2 && strcmp(argv[2], "x"))
+ asm volatile (
+ // 0 | zimm[10:0] | rs1 | 1 1 1 | rd |1010111| vsetvli
+ // vsetvli t4, x0, e8, m1, d1
+ ".insn 0b00000000000000000111111011010111\n\t"
+ "mv %[vl], t4\n\t"
+ : [vl] "=r" (vl) : : "t4"
+ );
+ else
+ asm volatile (
+ ".option push\n\t"
+ ".option arch, +v\n\t"
+ "vsetvli %[vl], x0, e8, m1, ta, ma\n\t"
+ ".option pop\n\t"
+ : [vl] "=r" (vl)
+ );

#define CHECK_VECTOR_REGISTER(register) ({ \
for (int i = 0; i < vl; i++) { \
diff --git a/tools/testing/selftests/riscv/vector/v_helpers.c b/tools/testing/selftests/riscv/vector/v_helpers.c
index 15c22318db72..2c4df76eefe9 100644
--- a/tools/testing/selftests/riscv/vector/v_helpers.c
+++ b/tools/testing/selftests/riscv/vector/v_helpers.c
@@ -1,11 +1,21 @@
// SPDX-License-Identifier: GPL-2.0-only

#include "../hwprobe/hwprobe.h"
+#include <asm/vendor/thead.h>
#include <stdlib.h>
#include <stdio.h>
#include <unistd.h>
#include <sys/wait.h>

+int is_xtheadvector_supported(void)
+{
+ struct riscv_hwprobe pair;
+
+ pair.key = RISCV_HWPROBE_KEY_VENDOR_EXT_THEAD_0;
+ riscv_hwprobe(&pair, 1, 0, NULL, 0);
+ return pair.value & RISCV_HWPROBE_VENDOR_EXT_XTHEADVECTOR;
+}
+
int is_vector_supported(void)
{
struct riscv_hwprobe pair;
@@ -15,9 +25,9 @@ int is_vector_supported(void)
return pair.value & RISCV_HWPROBE_IMA_V;
}

-int launch_test(char *next_program, int test_inherit)
+int launch_test(char *next_program, int test_inherit, int xtheadvector)
{
- char *exec_argv[3], *exec_envp[1];
+ char *exec_argv[4], *exec_envp[1];
int rc, pid, status;

pid = fork();
@@ -29,7 +39,8 @@ int launch_test(char *next_program, int test_inherit)
if (!pid) {
exec_argv[0] = next_program;
exec_argv[1] = test_inherit != 0 ? "x" : NULL;
- exec_argv[2] = NULL;
+ exec_argv[2] = xtheadvector != 0 ? "x" : NULL;
+ exec_argv[3] = NULL;
exec_envp[0] = NULL;
/* launch the program again to check inherit */
rc = execve(next_program, exec_argv, exec_envp);
diff --git a/tools/testing/selftests/riscv/vector/v_helpers.h b/tools/testing/selftests/riscv/vector/v_helpers.h
index 88719c4be496..67d41cb6f871 100644
--- a/tools/testing/selftests/riscv/vector/v_helpers.h
+++ b/tools/testing/selftests/riscv/vector/v_helpers.h
@@ -1,5 +1,7 @@
/* SPDX-License-Identifier: GPL-2.0-only */

+int is_xtheadvector_supported(void);
+
int is_vector_supported(void);

-int launch_test(char *next_program, int test_inherit);
+int launch_test(char *next_program, int test_inherit, int xtheadvector);
diff --git a/tools/testing/selftests/riscv/vector/v_initval.c b/tools/testing/selftests/riscv/vector/v_initval.c
index f38b5797fa31..be9e1d18ad29 100644
--- a/tools/testing/selftests/riscv/vector/v_initval.c
+++ b/tools/testing/selftests/riscv/vector/v_initval.c
@@ -7,10 +7,16 @@

TEST(v_initval)
{
- if (!is_vector_supported())
- SKIP(return, "Vector not supported");
+ int xtheadvector = 0;

- ASSERT_EQ(0, launch_test(NEXT_PROGRAM, 0));
+ if (!is_vector_supported()) {
+ if (is_xtheadvector_supported())
+ xtheadvector = 1;
+ else
+ SKIP(return, "Vector not supported");
+ }
+
+ ASSERT_EQ(0, launch_test(NEXT_PROGRAM, 0, xtheadvector));
}

TEST_HARNESS_MAIN
diff --git a/tools/testing/selftests/riscv/vector/vstate_exec_nolibc.c b/tools/testing/selftests/riscv/vector/vstate_exec_nolibc.c
index 1f9969bed235..12d30d3b90fa 100644
--- a/tools/testing/selftests/riscv/vector/vstate_exec_nolibc.c
+++ b/tools/testing/selftests/riscv/vector/vstate_exec_nolibc.c
@@ -6,13 +6,16 @@

int main(int argc, char **argv)
{
- int rc, pid, status, test_inherit = 0;
+ int rc, pid, status, test_inherit = 0, xtheadvector = 0;
long ctrl, ctrl_c;
char *exec_argv[2], *exec_envp[2];

- if (argc > 1)
+ if (argc > 1 && strcmp(argv[1], "x"))
test_inherit = 1;

+ if (argc > 2 && strcmp(argv[2], "x"))
+ xtheadvector = 1;
+
ctrl = my_syscall1(__NR_prctl, PR_RISCV_V_GET_CONTROL);
if (ctrl < 0) {
puts("PR_RISCV_V_GET_CONTROL is not supported\n");
@@ -53,11 +56,14 @@ int main(int argc, char **argv)
puts("child's vstate_ctrl not equal to parent's\n");
exit(-1);
}
- asm volatile (".option push\n\t"
- ".option arch, +v\n\t"
- "vsetvli x0, x0, e32, m8, ta, ma\n\t"
- ".option pop\n\t"
- );
+ if (xtheadvector)
+ asm volatile (".insn 0x00007ed7");
+ else
+ asm volatile (".option push\n\t"
+ ".option arch, +v\n\t"
+ "vsetvli x0, x0, e32, m8, ta, ma\n\t"
+ ".option pop\n\t"
+ );
exit(ctrl);
}
}
diff --git a/tools/testing/selftests/riscv/vector/vstate_prctl.c b/tools/testing/selftests/riscv/vector/vstate_prctl.c
index 528e8c544db0..375af40e88e6 100644
--- a/tools/testing/selftests/riscv/vector/vstate_prctl.c
+++ b/tools/testing/selftests/riscv/vector/vstate_prctl.c
@@ -11,7 +11,7 @@

#define NEXT_PROGRAM "./vstate_exec_nolibc"

-int test_and_compare_child(long provided, long expected, int inherit)
+int test_and_compare_child(long provided, long expected, int inherit, int xtheadvector)
{
int rc;

@@ -21,7 +21,7 @@ int test_and_compare_child(long provided, long expected, int inherit)
provided, rc);
return -1;
}
- rc = launch_test(NEXT_PROGRAM, inherit);
+ rc = launch_test(NEXT_PROGRAM, inherit, xtheadvector);
if (rc != expected) {
printf("Test failed, check %d != %ld\n", rc, expected);
return -2;
@@ -36,7 +36,7 @@ TEST(get_control_no_v)
{
long rc;

- if (is_vector_supported())
+ if (is_vector_supported() || is_xtheadvector_supported())
SKIP(return, "Test expects vector to be not supported");

rc = prctl(PR_RISCV_V_GET_CONTROL);
@@ -48,7 +48,7 @@ TEST(set_control_no_v)
{
long rc;

- if (is_vector_supported())
+ if (is_vector_supported() || is_xtheadvector_supported())
SKIP(return, "Test expects vector to be not supported");

rc = prctl(PR_RISCV_V_SET_CONTROL, PR_RISCV_V_VSTATE_CTRL_ON);
@@ -61,12 +61,12 @@ TEST(vstate_on_current)
long flag;
long rc;

- if (!is_vector_supported())
+ if (!is_vector_supported() && !is_xtheadvector_supported())
SKIP(return, "Vector not supported");

flag = PR_RISCV_V_VSTATE_CTRL_ON;
rc = prctl(PR_RISCV_V_SET_CONTROL, flag);
- EXPECT_EQ(0, rc) TH_LOG("Enabling V for current should always success");
+ EXPECT_EQ(0, rc) TH_LOG("Enabling V for current should always succeed");
}

TEST(vstate_off_eperm)
@@ -74,99 +74,128 @@ TEST(vstate_off_eperm)
long flag;
long rc;

- if (!is_vector_supported())
+ if (!is_vector_supported() && !is_xtheadvector_supported())
SKIP(return, "Vector not supported");

flag = PR_RISCV_V_VSTATE_CTRL_OFF;
rc = prctl(PR_RISCV_V_SET_CONTROL, flag);
- EXPECT_EQ(EPERM, errno) TH_LOG("Disabling current's V alive must fail with EPERM(%d)", errno);
- EXPECT_EQ(-1, rc) TH_LOG("Disabling current's V alive must fail with EPERM(%d)", errno);
+ EXPECT_EQ(EPERM, errno) TH_LOG("Disabling V in current thread with V enabled must fail with EPERM(%d)", errno);
+ EXPECT_EQ(-1, rc) TH_LOG("Disabling V in current thread with V enabled must fail with EPERM(%d)", errno);
}

TEST(vstate_on_no_nesting)
{
long flag;
+ int xtheadvector = 0;

- if (!is_vector_supported())
- SKIP(return, "Vector not supported");
+ if (!is_vector_supported()) {
+ if (is_xtheadvector_supported())
+ xtheadvector = 1;
+ else
+ SKIP(return, "Vector not supported");
+ }

/* Turn on next's vector explicitly and test */
flag = PR_RISCV_V_VSTATE_CTRL_ON << PR_RISCV_V_VSTATE_CTRL_NEXT_SHIFT;

- EXPECT_EQ(0, test_and_compare_child(flag, PR_RISCV_V_VSTATE_CTRL_ON, 0));
+ EXPECT_EQ(0, test_and_compare_child(flag, PR_RISCV_V_VSTATE_CTRL_ON, 0, xtheadvector));
}

TEST(vstate_off_nesting)
{
long flag;
+ int xtheadvector = 0;

- if (!is_vector_supported())
- SKIP(return, "Vector not supported");
+ if (!is_vector_supported()) {
+ if (is_xtheadvector_supported())
+ xtheadvector = 1;
+ else
+ SKIP(return, "Vector not supported");
+ }

/* Turn off next's vector explicitly and test */
flag = PR_RISCV_V_VSTATE_CTRL_OFF << PR_RISCV_V_VSTATE_CTRL_NEXT_SHIFT;

- EXPECT_EQ(0, test_and_compare_child(flag, PR_RISCV_V_VSTATE_CTRL_OFF, 1));
+ EXPECT_EQ(0, test_and_compare_child(flag, PR_RISCV_V_VSTATE_CTRL_OFF, 1, xtheadvector));
}

TEST(vstate_on_inherit_no_nesting)
{
long flag, expected;
+ int xtheadvector = 0;

- if (!is_vector_supported())
- SKIP(return, "Vector not supported");
+ if (!is_vector_supported()) {
+ if (is_xtheadvector_supported())
+ xtheadvector = 1;
+ else
+ SKIP(return, "Vector not supported");
+ }

/* Turn on next's vector explicitly and test no inherit */
flag = PR_RISCV_V_VSTATE_CTRL_ON << PR_RISCV_V_VSTATE_CTRL_NEXT_SHIFT;
flag |= PR_RISCV_V_VSTATE_CTRL_INHERIT;
expected = flag | PR_RISCV_V_VSTATE_CTRL_ON;

- EXPECT_EQ(0, test_and_compare_child(flag, expected, 0));
+ EXPECT_EQ(0, test_and_compare_child(flag, expected, 0, xtheadvector));
}

TEST(vstate_on_inherit)
{
long flag, expected;
+ int xtheadvector = 0;

- if (!is_vector_supported())
- SKIP(return, "Vector not supported");
+ if (!is_vector_supported()) {
+ if (is_xtheadvector_supported())
+ xtheadvector = 1;
+ else
+ SKIP(return, "Vector not supported");
+ }

/* Turn on next's vector explicitly and test inherit */
flag = PR_RISCV_V_VSTATE_CTRL_ON << PR_RISCV_V_VSTATE_CTRL_NEXT_SHIFT;
flag |= PR_RISCV_V_VSTATE_CTRL_INHERIT;
expected = flag | PR_RISCV_V_VSTATE_CTRL_ON;

- EXPECT_EQ(0, test_and_compare_child(flag, expected, 1));
+ EXPECT_EQ(0, test_and_compare_child(flag, expected, 1, xtheadvector));
}

TEST(vstate_off_inherit_no_nesting)
{
long flag, expected;
+ int xtheadvector = 0;

- if (!is_vector_supported())
- SKIP(return, "Vector not supported");
-
+ if (!is_vector_supported()) {
+ if (is_xtheadvector_supported())
+ xtheadvector = 1;
+ else
+ SKIP(return, "Vector not supported");
+ }
/* Turn off next's vector explicitly and test no inherit */
flag = PR_RISCV_V_VSTATE_CTRL_OFF << PR_RISCV_V_VSTATE_CTRL_NEXT_SHIFT;
flag |= PR_RISCV_V_VSTATE_CTRL_INHERIT;
expected = flag | PR_RISCV_V_VSTATE_CTRL_OFF;

- EXPECT_EQ(0, test_and_compare_child(flag, expected, 0));
+ EXPECT_EQ(0, test_and_compare_child(flag, expected, 0, xtheadvector));
}

TEST(vstate_off_inherit)
{
long flag, expected;
+ int xtheadvector = 0;

- if (!is_vector_supported())
- SKIP(return, "Vector not supported");
+ if (!is_vector_supported()) {
+ if (is_xtheadvector_supported())
+ xtheadvector = 1;
+ else
+ SKIP(return, "Vector not supported");
+ }

/* Turn off next's vector explicitly and test inherit */
flag = PR_RISCV_V_VSTATE_CTRL_OFF << PR_RISCV_V_VSTATE_CTRL_NEXT_SHIFT;
flag |= PR_RISCV_V_VSTATE_CTRL_INHERIT;
expected = flag | PR_RISCV_V_VSTATE_CTRL_OFF;

- EXPECT_EQ(0, test_and_compare_child(flag, expected, 1));
+ EXPECT_EQ(0, test_and_compare_child(flag, expected, 1, xtheadvector));
}

/* arguments should fail with EINVAL */
@@ -174,7 +203,7 @@ TEST(inval_set_control_1)
{
int rc;

- if (!is_vector_supported())
+ if (!is_vector_supported() && !is_xtheadvector_supported())
SKIP(return, "Vector not supported");

rc = prctl(PR_RISCV_V_SET_CONTROL, 0xff0);
@@ -187,7 +216,7 @@ TEST(inval_set_control_2)
{
int rc;

- if (!is_vector_supported())
+ if (!is_vector_supported() && !is_xtheadvector_supported())
SKIP(return, "Vector not supported");

rc = prctl(PR_RISCV_V_SET_CONTROL, 0x3);
@@ -200,7 +229,7 @@ TEST(inval_set_control_3)
{
int rc;

- if (!is_vector_supported())
+ if (!is_vector_supported() && !is_xtheadvector_supported())
SKIP(return, "Vector not supported");

rc = prctl(PR_RISCV_V_SET_CONTROL, 0xc);

--
2.44.0


2024-06-10 23:01:54

by Charlie Jenkins

[permalink] [raw]
Subject: [PATCH v2 10/13] riscv: hwprobe: Add thead vendor extension probing

Add a new hwprobe key "RISCV_HWPROBE_KEY_VENDOR_EXT_THEAD_0" which
allows userspace to probe for the new RISCV_ISA_VENDOR_EXT_XTHEADVECTOR
vendor extension.

This new key will allow userspace code to probe for which thead vendor
extensions are supported. This API is modeled to be consistent with
RISCV_HWPROBE_KEY_IMA_EXT_0. The bitmask returned will have each bit
corresponding to a supported thead vendor extension of the cpumask set.
Just like RISCV_HWPROBE_KEY_IMA_EXT_0, this allows a userspace program
to determine all of the supported thead vendor extensions in one call.

Signed-off-by: Charlie Jenkins <[email protected]>
Reviewed-by: Evan Green <[email protected]>
---
arch/riscv/include/asm/hwprobe.h | 4 +--
.../include/asm/vendor_extensions/thead_hwprobe.h | 18 +++++++++++
.../include/asm/vendor_extensions/vendor_hwprobe.h | 37 ++++++++++++++++++++++
arch/riscv/include/uapi/asm/hwprobe.h | 3 +-
arch/riscv/include/uapi/asm/vendor/thead.h | 3 ++
arch/riscv/kernel/sys_hwprobe.c | 5 +++
arch/riscv/kernel/vendor_extensions/Makefile | 1 +
.../riscv/kernel/vendor_extensions/thead_hwprobe.c | 19 +++++++++++
8 files changed, 87 insertions(+), 3 deletions(-)

diff --git a/arch/riscv/include/asm/hwprobe.h b/arch/riscv/include/asm/hwprobe.h
index 630507dff5ea..e68496b4f8de 100644
--- a/arch/riscv/include/asm/hwprobe.h
+++ b/arch/riscv/include/asm/hwprobe.h
@@ -1,6 +1,6 @@
/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
/*
- * Copyright 2023 Rivos, Inc
+ * Copyright 2023-2024 Rivos, Inc
*/

#ifndef _ASM_HWPROBE_H
@@ -8,7 +8,7 @@

#include <uapi/asm/hwprobe.h>

-#define RISCV_HWPROBE_MAX_KEY 6
+#define RISCV_HWPROBE_MAX_KEY 7

static inline bool riscv_hwprobe_key_is_valid(__s64 key)
{
diff --git a/arch/riscv/include/asm/vendor_extensions/thead_hwprobe.h b/arch/riscv/include/asm/vendor_extensions/thead_hwprobe.h
new file mode 100644
index 000000000000..925fef39a2c0
--- /dev/null
+++ b/arch/riscv/include/asm/vendor_extensions/thead_hwprobe.h
@@ -0,0 +1,18 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _ASM_RISCV_VENDOR_EXTENSIONS_THEAD_HWPROBE_H
+#define _ASM_RISCV_VENDOR_EXTENSIONS_THEAD_HWPROBE_H
+
+#include <linux/cpumask.h>
+
+#include <uapi/asm/hwprobe.h>
+
+#ifdef CONFIG_RISCV_ISA_VENDOR_EXT_THEAD
+void hwprobe_isa_vendor_ext_thead_0(struct riscv_hwprobe *pair, const struct cpumask *cpus);
+#else
+static inline void hwprobe_isa_vendor_ext_thead_0(struct riscv_hwprobe *pair, const struct cpumask *cpus)
+{
+ pair->value = 0;
+}
+#endif
+
+#endif
diff --git a/arch/riscv/include/asm/vendor_extensions/vendor_hwprobe.h b/arch/riscv/include/asm/vendor_extensions/vendor_hwprobe.h
new file mode 100644
index 000000000000..f28f31e19cda
--- /dev/null
+++ b/arch/riscv/include/asm/vendor_extensions/vendor_hwprobe.h
@@ -0,0 +1,37 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright 2024 Rivos, Inc
+ */
+
+#ifndef _ASM_RISCV_SYS_HWPROBE_H
+#define _ASM_RISCV_SYS_HWPROBE_H
+
+#include <asm/cpufeature.h>
+
+#define VENDOR_EXT_KEY(ext) \
+ do { \
+ if (__riscv_isa_extension_available(isainfo->isa, RISCV_ISA_VENDOR_EXT_##ext)) \
+ pair->value |= RISCV_HWPROBE_VENDOR_EXT_##ext; \
+ else \
+ missing |= RISCV_HWPROBE_VENDOR_EXT_##ext; \
+ } while (false)
+
+/*
+ * Loop through and record extensions that 1) anyone has, and 2) anyone
+ * doesn't have.
+ *
+ * _extension_checks is an arbitrary C block to set the values of pair->value
+ * and missing. It should be filled with VENDOR_EXT_KEY expressions.
+ */
+#define VENDOR_EXTENSION_SUPPORTED(pair, cpus, per_hart_vendor_bitmap, _extension_checks) \
+ do { \
+ int cpu; \
+ u64 missing; \
+ for_each_cpu(cpu, (cpus)) { \
+ struct riscv_isavendorinfo *isainfo = &(per_hart_vendor_bitmap)[cpu]; \
+ _extension_checks \
+ } \
+ (pair)->value &= ~missing; \
+ } while (false) \
+
+#endif /* _ASM_RISCV_SYS_HWPROBE_H */
diff --git a/arch/riscv/include/uapi/asm/hwprobe.h b/arch/riscv/include/uapi/asm/hwprobe.h
index dda76a05420b..155a83dd1cdf 100644
--- a/arch/riscv/include/uapi/asm/hwprobe.h
+++ b/arch/riscv/include/uapi/asm/hwprobe.h
@@ -1,6 +1,6 @@
/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
/*
- * Copyright 2023 Rivos, Inc
+ * Copyright 2023-2024 Rivos, Inc
*/

#ifndef _UAPI_ASM_HWPROBE_H
@@ -68,6 +68,7 @@ struct riscv_hwprobe {
#define RISCV_HWPROBE_MISALIGNED_UNSUPPORTED (4 << 0)
#define RISCV_HWPROBE_MISALIGNED_MASK (7 << 0)
#define RISCV_HWPROBE_KEY_ZICBOZ_BLOCK_SIZE 6
+#define RISCV_HWPROBE_KEY_VENDOR_EXT_THEAD_0 7
/* Increase RISCV_HWPROBE_MAX_KEY when adding items. */

/* Flags */
diff --git a/arch/riscv/include/uapi/asm/vendor/thead.h b/arch/riscv/include/uapi/asm/vendor/thead.h
new file mode 100644
index 000000000000..43790ebe5faf
--- /dev/null
+++ b/arch/riscv/include/uapi/asm/vendor/thead.h
@@ -0,0 +1,3 @@
+/* SPDX-License-Identifier: GPL-2.0 WITH Linux-syscall-note */
+
+#define RISCV_HWPROBE_VENDOR_EXT_XTHEADVECTOR (1 << 0)
diff --git a/arch/riscv/kernel/sys_hwprobe.c b/arch/riscv/kernel/sys_hwprobe.c
index 969ef3d59dbe..e39fa70083d3 100644
--- a/arch/riscv/kernel/sys_hwprobe.c
+++ b/arch/riscv/kernel/sys_hwprobe.c
@@ -13,6 +13,7 @@
#include <asm/uaccess.h>
#include <asm/unistd.h>
#include <asm/vector.h>
+#include <asm/vendor_extensions/thead_hwprobe.h>
#include <vdso/vsyscall.h>


@@ -217,6 +218,10 @@ static void hwprobe_one_pair(struct riscv_hwprobe *pair,
pair->value = riscv_cboz_block_size;
break;

+ case RISCV_HWPROBE_KEY_VENDOR_EXT_THEAD_0:
+ hwprobe_isa_vendor_ext_thead_0(pair, cpus);
+ break;
+
/*
* For forward compatibility, unknown keys don't fail the whole
* call, but get their element key set to -1 and value set to 0
diff --git a/arch/riscv/kernel/vendor_extensions/Makefile b/arch/riscv/kernel/vendor_extensions/Makefile
index 353522cb3bf0..866414c81a9f 100644
--- a/arch/riscv/kernel/vendor_extensions/Makefile
+++ b/arch/riscv/kernel/vendor_extensions/Makefile
@@ -2,3 +2,4 @@

obj-$(CONFIG_RISCV_ISA_VENDOR_EXT_ANDES) += andes.o
obj-$(CONFIG_RISCV_ISA_VENDOR_EXT_THEAD) += thead.o
+obj-$(CONFIG_RISCV_ISA_VENDOR_EXT_THEAD) += thead_hwprobe.o
diff --git a/arch/riscv/kernel/vendor_extensions/thead_hwprobe.c b/arch/riscv/kernel/vendor_extensions/thead_hwprobe.c
new file mode 100644
index 000000000000..2eba34011786
--- /dev/null
+++ b/arch/riscv/kernel/vendor_extensions/thead_hwprobe.c
@@ -0,0 +1,19 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include <asm/vendor_extensions/thead.h>
+#include <asm/vendor_extensions/thead_hwprobe.h>
+#include <asm/vendor_extensions/vendor_hwprobe.h>
+
+#include <linux/cpumask.h>
+#include <linux/types.h>
+
+#include <uapi/asm/hwprobe.h>
+#include <uapi/asm/vendor/thead.h>
+
+void hwprobe_isa_vendor_ext_thead_0(struct riscv_hwprobe *pair, const struct cpumask *cpus)
+{
+ VENDOR_EXTENSION_SUPPORTED(pair, cpus,
+ riscv_isa_vendor_ext_list_thead.per_hart_isa_bitmap, {
+ VENDOR_EXT_KEY(XTHEADVECTOR);
+ });
+}

--
2.44.0


2024-06-10 23:01:58

by Charlie Jenkins

[permalink] [raw]
Subject: [PATCH v2 11/13] riscv: hwprobe: Document thead vendor extensions and xtheadvector extension

Document support for thead vendor extensions using the key
RISCV_HWPROBE_KEY_VENDOR_EXT_THEAD_0 and xtheadvector extension using
the key RISCV_HWPROBE_VENDOR_EXT_XTHEADVECTOR.

Signed-off-by: Charlie Jenkins <[email protected]>
Reviewed-by: Evan Green <[email protected]>
---
Documentation/arch/riscv/hwprobe.rst | 10 ++++++++++
1 file changed, 10 insertions(+)

diff --git a/Documentation/arch/riscv/hwprobe.rst b/Documentation/arch/riscv/hwprobe.rst
index 204cd4433af5..9c0ef8c57228 100644
--- a/Documentation/arch/riscv/hwprobe.rst
+++ b/Documentation/arch/riscv/hwprobe.rst
@@ -214,3 +214,13 @@ The following keys are defined:

* :c:macro:`RISCV_HWPROBE_KEY_ZICBOZ_BLOCK_SIZE`: An unsigned int which
represents the size of the Zicboz block in bytes.
+
+* :c:macro:`RISCV_HWPROBE_KEY_VENDOR_EXT_THEAD_0`: A bitmask containing the
+ thead vendor extensions that are compatible with the
+ :c:macro:`RISCV_HWPROBE_BASE_BEHAVIOR_IMA`: base system behavior.
+
+ * T-HEAD
+
+ * :c:macro:`RISCV_HWPROBE_VENDOR_EXT_XTHEADVECTOR`: The xtheadvector vendor
+ extension is supported in the T-Head ISA extensions spec starting from
+ commit a18c801634 ("Add T-Head VECTOR vendor extension. ").

--
2.44.0


2024-06-10 23:02:54

by Charlie Jenkins

[permalink] [raw]
Subject: [PATCH v2 12/13] selftests: riscv: Fix vector tests

Overhaul the riscv vector tests to use kselftest_harness to help the
test cases correctly report the results and decouple the individual test
cases from each other. With this refactoring, only run the test cases is
vector is reported and properly report the test case as skipped
otherwise. The v_initval_nolibc test was previously not checking if
vector was supported and used a function (malloc) which invalidates
the state of the vector registers.

Signed-off-by: Charlie Jenkins <[email protected]>
---
tools/testing/selftests/riscv/vector/.gitignore | 3 +-
tools/testing/selftests/riscv/vector/Makefile | 17 +-
.../selftests/riscv/vector/v_exec_initval_nolibc.c | 84 +++++++
tools/testing/selftests/riscv/vector/v_helpers.c | 56 +++++
tools/testing/selftests/riscv/vector/v_helpers.h | 5 +
tools/testing/selftests/riscv/vector/v_initval.c | 16 ++
.../selftests/riscv/vector/v_initval_nolibc.c | 68 ------
.../testing/selftests/riscv/vector/vstate_prctl.c | 266 ++++++++++++---------
8 files changed, 324 insertions(+), 191 deletions(-)

diff --git a/tools/testing/selftests/riscv/vector/.gitignore b/tools/testing/selftests/riscv/vector/.gitignore
index 9ae7964491d5..7d9c87cd0649 100644
--- a/tools/testing/selftests/riscv/vector/.gitignore
+++ b/tools/testing/selftests/riscv/vector/.gitignore
@@ -1,3 +1,4 @@
vstate_exec_nolibc
vstate_prctl
-v_initval_nolibc
+v_initval
+v_exec_initval_nolibc
diff --git a/tools/testing/selftests/riscv/vector/Makefile b/tools/testing/selftests/riscv/vector/Makefile
index bfff0ff4f3be..995746359477 100644
--- a/tools/testing/selftests/riscv/vector/Makefile
+++ b/tools/testing/selftests/riscv/vector/Makefile
@@ -2,18 +2,27 @@
# Copyright (C) 2021 ARM Limited
# Originally tools/testing/arm64/abi/Makefile

-TEST_GEN_PROGS := vstate_prctl v_initval_nolibc
-TEST_GEN_PROGS_EXTENDED := vstate_exec_nolibc
+TEST_GEN_PROGS := v_initval vstate_prctl
+TEST_GEN_PROGS_EXTENDED := vstate_exec_nolibc v_exec_initval_nolibc sys_hwprobe.o v_helpers.o

include ../../lib.mk

-$(OUTPUT)/vstate_prctl: vstate_prctl.c ../hwprobe/sys_hwprobe.S
+$(OUTPUT)/sys_hwprobe.o: ../hwprobe/sys_hwprobe.S
+ $(CC) -static -c -o$@ $(CFLAGS) $^
+
+$(OUTPUT)/v_helpers.o: v_helpers.c
+ $(CC) -static -c -o$@ $(CFLAGS) $^
+
+$(OUTPUT)/vstate_prctl: vstate_prctl.c $(OUTPUT)/sys_hwprobe.o $(OUTPUT)/v_helpers.o
$(CC) -static -o$@ $(CFLAGS) $(LDFLAGS) $^

$(OUTPUT)/vstate_exec_nolibc: vstate_exec_nolibc.c
$(CC) -nostdlib -static -include ../../../../include/nolibc/nolibc.h \
-Wall $(CFLAGS) $(LDFLAGS) $^ -o $@ -lgcc

-$(OUTPUT)/v_initval_nolibc: v_initval_nolibc.c
+$(OUTPUT)/v_initval: v_initval.c $(OUTPUT)/sys_hwprobe.o $(OUTPUT)/v_helpers.o
+ $(CC) -static -o$@ $(CFLAGS) $(LDFLAGS) $^
+
+$(OUTPUT)/v_exec_initval_nolibc: v_exec_initval_nolibc.c
$(CC) -nostdlib -static -include ../../../../include/nolibc/nolibc.h \
-Wall $(CFLAGS) $(LDFLAGS) $^ -o $@ -lgcc
diff --git a/tools/testing/selftests/riscv/vector/v_exec_initval_nolibc.c b/tools/testing/selftests/riscv/vector/v_exec_initval_nolibc.c
new file mode 100644
index 000000000000..74b13806baf0
--- /dev/null
+++ b/tools/testing/selftests/riscv/vector/v_exec_initval_nolibc.c
@@ -0,0 +1,84 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Get values of vector registers as soon as the program starts to test if
+ * is properly cleaning the values before starting a new program. Vector
+ * registers are caller saved, so no function calls may happen before reading
+ * the values. To further ensure consistency, this file is compiled without
+ * libc and without auto-vectorization.
+ *
+ * To be "clean" all values must be either all ones or all zeroes.
+ */
+
+#define __stringify_1(x...) #x
+#define __stringify(x...) __stringify_1(x)
+
+int main(int argc, char **argv)
+{
+ char prev_value = 0, value;
+ unsigned long vl;
+ int first = 1;
+
+ asm volatile (
+ ".option push\n\t"
+ ".option arch, +v\n\t"
+ "vsetvli %[vl], x0, e8, m1, ta, ma\n\t"
+ ".option pop\n\t"
+ : [vl] "=r" (vl)
+ );
+
+#define CHECK_VECTOR_REGISTER(register) ({ \
+ for (int i = 0; i < vl; i++) { \
+ asm volatile ( \
+ ".option push\n\t" \
+ ".option arch, +v\n\t" \
+ "vmv.x.s %0, " __stringify(register) "\n\t" \
+ "vsrl.vi " __stringify(register) ", " __stringify(register) ", 8\n\t" \
+ ".option pop\n\t" \
+ : "=r" (value)); \
+ if (first) { \
+ first = 0; \
+ } else if (value != prev_value || !(value == 0x00 || value == 0xff)) { \
+ printf("Register " __stringify(register) " values not clean! value: %u\n", value); \
+ exit(-1); \
+ } \
+ prev_value = value; \
+ } \
+})
+
+ CHECK_VECTOR_REGISTER(v0);
+ CHECK_VECTOR_REGISTER(v1);
+ CHECK_VECTOR_REGISTER(v2);
+ CHECK_VECTOR_REGISTER(v3);
+ CHECK_VECTOR_REGISTER(v4);
+ CHECK_VECTOR_REGISTER(v5);
+ CHECK_VECTOR_REGISTER(v6);
+ CHECK_VECTOR_REGISTER(v7);
+ CHECK_VECTOR_REGISTER(v8);
+ CHECK_VECTOR_REGISTER(v9);
+ CHECK_VECTOR_REGISTER(v10);
+ CHECK_VECTOR_REGISTER(v11);
+ CHECK_VECTOR_REGISTER(v12);
+ CHECK_VECTOR_REGISTER(v13);
+ CHECK_VECTOR_REGISTER(v14);
+ CHECK_VECTOR_REGISTER(v15);
+ CHECK_VECTOR_REGISTER(v16);
+ CHECK_VECTOR_REGISTER(v17);
+ CHECK_VECTOR_REGISTER(v18);
+ CHECK_VECTOR_REGISTER(v19);
+ CHECK_VECTOR_REGISTER(v20);
+ CHECK_VECTOR_REGISTER(v21);
+ CHECK_VECTOR_REGISTER(v22);
+ CHECK_VECTOR_REGISTER(v23);
+ CHECK_VECTOR_REGISTER(v24);
+ CHECK_VECTOR_REGISTER(v25);
+ CHECK_VECTOR_REGISTER(v26);
+ CHECK_VECTOR_REGISTER(v27);
+ CHECK_VECTOR_REGISTER(v28);
+ CHECK_VECTOR_REGISTER(v29);
+ CHECK_VECTOR_REGISTER(v30);
+ CHECK_VECTOR_REGISTER(v31);
+
+#undef CHECK_VECTOR_REGISTER
+
+ return 0;
+}
diff --git a/tools/testing/selftests/riscv/vector/v_helpers.c b/tools/testing/selftests/riscv/vector/v_helpers.c
new file mode 100644
index 000000000000..15c22318db72
--- /dev/null
+++ b/tools/testing/selftests/riscv/vector/v_helpers.c
@@ -0,0 +1,56 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include "../hwprobe/hwprobe.h"
+#include <stdlib.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/wait.h>
+
+int is_vector_supported(void)
+{
+ struct riscv_hwprobe pair;
+
+ pair.key = RISCV_HWPROBE_KEY_IMA_EXT_0;
+ riscv_hwprobe(&pair, 1, 0, NULL, 0);
+ return pair.value & RISCV_HWPROBE_IMA_V;
+}
+
+int launch_test(char *next_program, int test_inherit)
+{
+ char *exec_argv[3], *exec_envp[1];
+ int rc, pid, status;
+
+ pid = fork();
+ if (pid < 0) {
+ printf("fork failed %d", pid);
+ return -1;
+ }
+
+ if (!pid) {
+ exec_argv[0] = next_program;
+ exec_argv[1] = test_inherit != 0 ? "x" : NULL;
+ exec_argv[2] = NULL;
+ exec_envp[0] = NULL;
+ /* launch the program again to check inherit */
+ rc = execve(next_program, exec_argv, exec_envp);
+ if (rc) {
+ perror("execve");
+ printf("child execve failed %d\n", rc);
+ exit(-1);
+ }
+ }
+
+ rc = waitpid(-1, &status, 0);
+ if (rc < 0) {
+ printf("waitpid failed\n");
+ return -3;
+ }
+
+ if ((WIFEXITED(status) && WEXITSTATUS(status) == -1) ||
+ WIFSIGNALED(status)) {
+ printf("child exited abnormally\n");
+ return -4;
+ }
+
+ return WEXITSTATUS(status);
+}
diff --git a/tools/testing/selftests/riscv/vector/v_helpers.h b/tools/testing/selftests/riscv/vector/v_helpers.h
new file mode 100644
index 000000000000..88719c4be496
--- /dev/null
+++ b/tools/testing/selftests/riscv/vector/v_helpers.h
@@ -0,0 +1,5 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+int is_vector_supported(void);
+
+int launch_test(char *next_program, int test_inherit);
diff --git a/tools/testing/selftests/riscv/vector/v_initval.c b/tools/testing/selftests/riscv/vector/v_initval.c
new file mode 100644
index 000000000000..f38b5797fa31
--- /dev/null
+++ b/tools/testing/selftests/riscv/vector/v_initval.c
@@ -0,0 +1,16 @@
+// SPDX-License-Identifier: GPL-2.0-only
+
+#include "../../kselftest_harness.h"
+#include "v_helpers.h"
+
+#define NEXT_PROGRAM "./v_exec_initval_nolibc"
+
+TEST(v_initval)
+{
+ if (!is_vector_supported())
+ SKIP(return, "Vector not supported");
+
+ ASSERT_EQ(0, launch_test(NEXT_PROGRAM, 0));
+}
+
+TEST_HARNESS_MAIN
diff --git a/tools/testing/selftests/riscv/vector/v_initval_nolibc.c b/tools/testing/selftests/riscv/vector/v_initval_nolibc.c
deleted file mode 100644
index 1dd94197da30..000000000000
--- a/tools/testing/selftests/riscv/vector/v_initval_nolibc.c
+++ /dev/null
@@ -1,68 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0-only
-
-#include "../../kselftest.h"
-#define MAX_VSIZE (8192 * 32)
-
-void dump(char *ptr, int size)
-{
- int i = 0;
-
- for (i = 0; i < size; i++) {
- if (i != 0) {
- if (i % 16 == 0)
- printf("\n");
- else if (i % 8 == 0)
- printf(" ");
- }
- printf("%02x ", ptr[i]);
- }
- printf("\n");
-}
-
-int main(void)
-{
- int i;
- unsigned long vl;
- char *datap, *tmp;
-
- datap = malloc(MAX_VSIZE);
- if (!datap) {
- ksft_test_result_fail("fail to allocate memory for size = %d\n", MAX_VSIZE);
- exit(-1);
- }
-
- tmp = datap;
- asm volatile (
- ".option push\n\t"
- ".option arch, +v\n\t"
- "vsetvli %0, x0, e8, m8, ta, ma\n\t"
- "vse8.v v0, (%2)\n\t"
- "add %1, %2, %0\n\t"
- "vse8.v v8, (%1)\n\t"
- "add %1, %1, %0\n\t"
- "vse8.v v16, (%1)\n\t"
- "add %1, %1, %0\n\t"
- "vse8.v v24, (%1)\n\t"
- ".option pop\n\t"
- : "=&r" (vl), "=r" (tmp) : "r" (datap) : "memory");
-
- ksft_print_msg("vl = %lu\n", vl);
-
- if (datap[0] != 0x00 && datap[0] != 0xff) {
- ksft_test_result_fail("v-regesters are not properly initialized\n");
- dump(datap, vl * 4);
- exit(-1);
- }
-
- for (i = 1; i < vl * 4; i++) {
- if (datap[i] != datap[0]) {
- ksft_test_result_fail("detect stale values on v-regesters\n");
- dump(datap, vl * 4);
- exit(-2);
- }
- }
-
- free(datap);
- ksft_exit_pass();
- return 0;
-}
diff --git a/tools/testing/selftests/riscv/vector/vstate_prctl.c b/tools/testing/selftests/riscv/vector/vstate_prctl.c
index 27668fb3b6d0..528e8c544db0 100644
--- a/tools/testing/selftests/riscv/vector/vstate_prctl.c
+++ b/tools/testing/selftests/riscv/vector/vstate_prctl.c
@@ -3,50 +3,13 @@
#include <unistd.h>
#include <errno.h>
#include <sys/wait.h>
+#include <sys/types.h>
+#include <stdlib.h>

-#include "../hwprobe/hwprobe.h"
-#include "../../kselftest.h"
+#include "../../kselftest_harness.h"
+#include "v_helpers.h"

#define NEXT_PROGRAM "./vstate_exec_nolibc"
-static int launch_test(int test_inherit)
-{
- char *exec_argv[3], *exec_envp[1];
- int rc, pid, status;
-
- pid = fork();
- if (pid < 0) {
- ksft_test_result_fail("fork failed %d", pid);
- return -1;
- }
-
- if (!pid) {
- exec_argv[0] = NEXT_PROGRAM;
- exec_argv[1] = test_inherit != 0 ? "x" : NULL;
- exec_argv[2] = NULL;
- exec_envp[0] = NULL;
- /* launch the program again to check inherit */
- rc = execve(NEXT_PROGRAM, exec_argv, exec_envp);
- if (rc) {
- perror("execve");
- ksft_test_result_fail("child execve failed %d\n", rc);
- exit(-1);
- }
- }
-
- rc = waitpid(-1, &status, 0);
- if (rc < 0) {
- ksft_test_result_fail("waitpid failed\n");
- return -3;
- }
-
- if ((WIFEXITED(status) && WEXITSTATUS(status) == -1) ||
- WIFSIGNALED(status)) {
- ksft_test_result_fail("child exited abnormally\n");
- return -4;
- }
-
- return WEXITSTATUS(status);
-}

int test_and_compare_child(long provided, long expected, int inherit)
{
@@ -54,14 +17,13 @@ int test_and_compare_child(long provided, long expected, int inherit)

rc = prctl(PR_RISCV_V_SET_CONTROL, provided);
if (rc != 0) {
- ksft_test_result_fail("prctl with provided arg %lx failed with code %d\n",
- provided, rc);
+ printf("prctl with provided arg %lx failed with code %d\n",
+ provided, rc);
return -1;
}
- rc = launch_test(inherit);
+ rc = launch_test(NEXT_PROGRAM, inherit);
if (rc != expected) {
- ksft_test_result_fail("Test failed, check %d != %ld\n", rc,
- expected);
+ printf("Test failed, check %d != %ld\n", rc, expected);
return -2;
}
return 0;
@@ -70,112 +32,180 @@ int test_and_compare_child(long provided, long expected, int inherit)
#define PR_RISCV_V_VSTATE_CTRL_CUR_SHIFT 0
#define PR_RISCV_V_VSTATE_CTRL_NEXT_SHIFT 2

-int main(void)
+TEST(get_control_no_v)
{
- struct riscv_hwprobe pair;
- long flag, expected;
long rc;

- pair.key = RISCV_HWPROBE_KEY_IMA_EXT_0;
- rc = riscv_hwprobe(&pair, 1, 0, NULL, 0);
- if (rc < 0) {
- ksft_test_result_fail("hwprobe() failed with %ld\n", rc);
- return -1;
- }
+ if (is_vector_supported())
+ SKIP(return, "Test expects vector to be not supported");

- if (pair.key != RISCV_HWPROBE_KEY_IMA_EXT_0) {
- ksft_test_result_fail("hwprobe cannot probe RISCV_HWPROBE_KEY_IMA_EXT_0\n");
- return -2;
- }
+ rc = prctl(PR_RISCV_V_GET_CONTROL);
+ EXPECT_EQ(-1, rc) TH_LOG("GET_CONTROL should fail on kernel/hw without V");
+ EXPECT_EQ(EINVAL, errno) TH_LOG("GET_CONTROL should fail on kernel/hw without V");
+}

- if (!(pair.value & RISCV_HWPROBE_IMA_V)) {
- rc = prctl(PR_RISCV_V_GET_CONTROL);
- if (rc != -1 || errno != EINVAL) {
- ksft_test_result_fail("GET_CONTROL should fail on kernel/hw without V\n");
- return -3;
- }
-
- rc = prctl(PR_RISCV_V_SET_CONTROL, PR_RISCV_V_VSTATE_CTRL_ON);
- if (rc != -1 || errno != EINVAL) {
- ksft_test_result_fail("GET_CONTROL should fail on kernel/hw without V\n");
- return -4;
- }
-
- ksft_test_result_skip("Vector not supported\n");
- return 0;
- }
+TEST(set_control_no_v)
+{
+ long rc;
+
+ if (is_vector_supported())
+ SKIP(return, "Test expects vector to be not supported");
+
+ rc = prctl(PR_RISCV_V_SET_CONTROL, PR_RISCV_V_VSTATE_CTRL_ON);
+ EXPECT_EQ(-1, rc) TH_LOG("SET_CONTROL should fail on kernel/hw without V");
+ EXPECT_EQ(EINVAL, errno) TH_LOG("SET_CONTROL should fail on kernel/hw without V");
+}
+
+TEST(vstate_on_current)
+{
+ long flag;
+ long rc;
+
+ if (!is_vector_supported())
+ SKIP(return, "Vector not supported");

flag = PR_RISCV_V_VSTATE_CTRL_ON;
rc = prctl(PR_RISCV_V_SET_CONTROL, flag);
- if (rc != 0) {
- ksft_test_result_fail("Enabling V for current should always success\n");
- return -5;
- }
+ EXPECT_EQ(0, rc) TH_LOG("Enabling V for current should always success");
+}
+
+TEST(vstate_off_eperm)
+{
+ long flag;
+ long rc;
+
+ if (!is_vector_supported())
+ SKIP(return, "Vector not supported");

flag = PR_RISCV_V_VSTATE_CTRL_OFF;
rc = prctl(PR_RISCV_V_SET_CONTROL, flag);
- if (rc != -1 || errno != EPERM) {
- ksft_test_result_fail("Disabling current's V alive must fail with EPERM(%d)\n",
- errno);
- return -5;
- }
+ EXPECT_EQ(EPERM, errno) TH_LOG("Disabling current's V alive must fail with EPERM(%d)", errno);
+ EXPECT_EQ(-1, rc) TH_LOG("Disabling current's V alive must fail with EPERM(%d)", errno);
+}
+
+TEST(vstate_on_no_nesting)
+{
+ long flag;
+
+ if (!is_vector_supported())
+ SKIP(return, "Vector not supported");

/* Turn on next's vector explicitly and test */
flag = PR_RISCV_V_VSTATE_CTRL_ON << PR_RISCV_V_VSTATE_CTRL_NEXT_SHIFT;
- if (test_and_compare_child(flag, PR_RISCV_V_VSTATE_CTRL_ON, 0))
- return -6;
+
+ EXPECT_EQ(0, test_and_compare_child(flag, PR_RISCV_V_VSTATE_CTRL_ON, 0));
+}
+
+TEST(vstate_off_nesting)
+{
+ long flag;
+
+ if (!is_vector_supported())
+ SKIP(return, "Vector not supported");

/* Turn off next's vector explicitly and test */
flag = PR_RISCV_V_VSTATE_CTRL_OFF << PR_RISCV_V_VSTATE_CTRL_NEXT_SHIFT;
- if (test_and_compare_child(flag, PR_RISCV_V_VSTATE_CTRL_OFF, 0))
- return -7;
+
+ EXPECT_EQ(0, test_and_compare_child(flag, PR_RISCV_V_VSTATE_CTRL_OFF, 1));
+}
+
+TEST(vstate_on_inherit_no_nesting)
+{
+ long flag, expected;
+
+ if (!is_vector_supported())
+ SKIP(return, "Vector not supported");
+
+ /* Turn on next's vector explicitly and test no inherit */
+ flag = PR_RISCV_V_VSTATE_CTRL_ON << PR_RISCV_V_VSTATE_CTRL_NEXT_SHIFT;
+ flag |= PR_RISCV_V_VSTATE_CTRL_INHERIT;
+ expected = flag | PR_RISCV_V_VSTATE_CTRL_ON;
+
+ EXPECT_EQ(0, test_and_compare_child(flag, expected, 0));
+}
+
+TEST(vstate_on_inherit)
+{
+ long flag, expected;
+
+ if (!is_vector_supported())
+ SKIP(return, "Vector not supported");

/* Turn on next's vector explicitly and test inherit */
flag = PR_RISCV_V_VSTATE_CTRL_ON << PR_RISCV_V_VSTATE_CTRL_NEXT_SHIFT;
flag |= PR_RISCV_V_VSTATE_CTRL_INHERIT;
expected = flag | PR_RISCV_V_VSTATE_CTRL_ON;
- if (test_and_compare_child(flag, expected, 0))
- return -8;

- if (test_and_compare_child(flag, expected, 1))
- return -9;
+ EXPECT_EQ(0, test_and_compare_child(flag, expected, 1));
+}
+
+TEST(vstate_off_inherit_no_nesting)
+{
+ long flag, expected;
+
+ if (!is_vector_supported())
+ SKIP(return, "Vector not supported");
+
+ /* Turn off next's vector explicitly and test no inherit */
+ flag = PR_RISCV_V_VSTATE_CTRL_OFF << PR_RISCV_V_VSTATE_CTRL_NEXT_SHIFT;
+ flag |= PR_RISCV_V_VSTATE_CTRL_INHERIT;
+ expected = flag | PR_RISCV_V_VSTATE_CTRL_OFF;
+
+ EXPECT_EQ(0, test_and_compare_child(flag, expected, 0));
+}
+
+TEST(vstate_off_inherit)
+{
+ long flag, expected;
+
+ if (!is_vector_supported())
+ SKIP(return, "Vector not supported");

/* Turn off next's vector explicitly and test inherit */
flag = PR_RISCV_V_VSTATE_CTRL_OFF << PR_RISCV_V_VSTATE_CTRL_NEXT_SHIFT;
flag |= PR_RISCV_V_VSTATE_CTRL_INHERIT;
expected = flag | PR_RISCV_V_VSTATE_CTRL_OFF;
- if (test_and_compare_child(flag, expected, 0))
- return -10;

- if (test_and_compare_child(flag, expected, 1))
- return -11;
+ EXPECT_EQ(0, test_and_compare_child(flag, expected, 1));
+}
+
+/* arguments should fail with EINVAL */
+TEST(inval_set_control_1)
+{
+ int rc;
+
+ if (!is_vector_supported())
+ SKIP(return, "Vector not supported");

- /* arguments should fail with EINVAL */
rc = prctl(PR_RISCV_V_SET_CONTROL, 0xff0);
- if (rc != -1 || errno != EINVAL) {
- ksft_test_result_fail("Undefined control argument should return EINVAL\n");
- return -12;
- }
+ EXPECT_EQ(-1, rc);
+ EXPECT_EQ(EINVAL, errno);
+}
+
+/* arguments should fail with EINVAL */
+TEST(inval_set_control_2)
+{
+ int rc;
+
+ if (!is_vector_supported())
+ SKIP(return, "Vector not supported");

rc = prctl(PR_RISCV_V_SET_CONTROL, 0x3);
- if (rc != -1 || errno != EINVAL) {
- ksft_test_result_fail("Undefined control argument should return EINVAL\n");
- return -12;
- }
+ EXPECT_EQ(-1, rc);
+ EXPECT_EQ(EINVAL, errno);
+}

- rc = prctl(PR_RISCV_V_SET_CONTROL, 0xc);
- if (rc != -1 || errno != EINVAL) {
- ksft_test_result_fail("Undefined control argument should return EINVAL\n");
- return -12;
- }
+/* arguments should fail with EINVAL */
+TEST(inval_set_control_3)
+{
+ int rc;

- rc = prctl(PR_RISCV_V_SET_CONTROL, 0xc);
- if (rc != -1 || errno != EINVAL) {
- ksft_test_result_fail("Undefined control argument should return EINVAL\n");
- return -12;
- }
+ if (!is_vector_supported())
+ SKIP(return, "Vector not supported");

- ksft_test_result_pass("tests for riscv_v_vstate_ctrl pass\n");
- ksft_exit_pass();
- return 0;
+ rc = prctl(PR_RISCV_V_SET_CONTROL, 0xc);
+ EXPECT_EQ(-1, rc);
+ EXPECT_EQ(EINVAL, errno);
}
+
+TEST_HARNESS_MAIN

--
2.44.0


2024-06-10 23:08:05

by Charlie Jenkins

[permalink] [raw]
Subject: [PATCH v2 09/13] riscv: vector: Support xtheadvector save/restore

Use alternatives to add support for xtheadvector vector save/restore
routines.

Signed-off-by: Charlie Jenkins <[email protected]>
---
arch/riscv/include/asm/csr.h | 6 +
arch/riscv/include/asm/switch_to.h | 2 +-
arch/riscv/include/asm/vector.h | 249 ++++++++++++++++++++++++++-------
arch/riscv/kernel/cpufeature.c | 2 +-
arch/riscv/kernel/kernel_mode_vector.c | 8 +-
arch/riscv/kernel/process.c | 4 +-
arch/riscv/kernel/signal.c | 6 +-
arch/riscv/kernel/vector.c | 13 +-
8 files changed, 222 insertions(+), 68 deletions(-)

diff --git a/arch/riscv/include/asm/csr.h b/arch/riscv/include/asm/csr.h
index 9086639a3dde..407d4a5687f5 100644
--- a/arch/riscv/include/asm/csr.h
+++ b/arch/riscv/include/asm/csr.h
@@ -30,6 +30,12 @@
#define SR_VS_CLEAN _AC(0x00000400, UL)
#define SR_VS_DIRTY _AC(0x00000600, UL)

+#define SR_VS_THEAD _AC(0x01800000, UL) /* xtheadvector Status */
+#define SR_VS_OFF_THEAD _AC(0x00000000, UL)
+#define SR_VS_INITIAL_THEAD _AC(0x00800000, UL)
+#define SR_VS_CLEAN_THEAD _AC(0x01000000, UL)
+#define SR_VS_DIRTY_THEAD _AC(0x01800000, UL)
+
#define SR_XS _AC(0x00018000, UL) /* Extension Status */
#define SR_XS_OFF _AC(0x00000000, UL)
#define SR_XS_INITIAL _AC(0x00008000, UL)
diff --git a/arch/riscv/include/asm/switch_to.h b/arch/riscv/include/asm/switch_to.h
index 7594df37cc9f..f9cbebe372b8 100644
--- a/arch/riscv/include/asm/switch_to.h
+++ b/arch/riscv/include/asm/switch_to.h
@@ -99,7 +99,7 @@ do { \
__set_prev_cpu(__prev->thread); \
if (has_fpu()) \
__switch_to_fpu(__prev, __next); \
- if (has_vector()) \
+ if (has_vector() || has_xtheadvector()) \
__switch_to_vector(__prev, __next); \
if (switch_to_should_flush_icache(__next)) \
local_flush_icache_all(); \
diff --git a/arch/riscv/include/asm/vector.h b/arch/riscv/include/asm/vector.h
index 731dcd0ed4de..6294dcaabc6a 100644
--- a/arch/riscv/include/asm/vector.h
+++ b/arch/riscv/include/asm/vector.h
@@ -18,6 +18,27 @@
#include <asm/cpufeature.h>
#include <asm/csr.h>
#include <asm/asm.h>
+#include <asm/vendorid_list.h>
+#include <asm/vendor_extensions.h>
+#include <asm/vendor_extensions/thead.h>
+
+#define __riscv_v_vstate_or(_val, TYPE) ({ \
+ typeof(_val) _res = _val; \
+ if (has_xtheadvector()) \
+ _res = (_res & ~SR_VS_THEAD) | SR_VS_##TYPE##_THEAD; \
+ else \
+ _res = (_res & ~SR_VS) | SR_VS_##TYPE; \
+ _res; \
+})
+
+#define __riscv_v_vstate_check(_val, TYPE) ({ \
+ bool _res; \
+ if (has_xtheadvector()) \
+ _res = ((_val) & SR_VS_THEAD) == SR_VS_##TYPE##_THEAD; \
+ else \
+ _res = ((_val) & SR_VS) == SR_VS_##TYPE; \
+ _res; \
+})

extern unsigned long riscv_v_vsize;
int riscv_v_setup_vsize(void);
@@ -40,39 +61,62 @@ static __always_inline bool has_vector(void)
return riscv_has_extension_unlikely(RISCV_ISA_EXT_v);
}

+static __always_inline bool has_xtheadvector_no_alternatives(void)
+{
+ if (IS_ENABLED(CONFIG_RISCV_ISA_XTHEADVECTOR))
+ return riscv_isa_vendor_extension_available(THEAD_VENDOR_ID, XTHEADVECTOR);
+ else
+ return false;
+}
+
+static __always_inline bool has_xtheadvector(void)
+{
+ if (IS_ENABLED(CONFIG_RISCV_ISA_XTHEADVECTOR))
+ return riscv_has_vendor_extension_unlikely(THEAD_VENDOR_ID,
+ RISCV_ISA_VENDOR_EXT_XTHEADVECTOR);
+ else
+ return false;
+}
+
static inline void __riscv_v_vstate_clean(struct pt_regs *regs)
{
- regs->status = (regs->status & ~SR_VS) | SR_VS_CLEAN;
+ regs->status = __riscv_v_vstate_or(regs->status, CLEAN);
}

static inline void __riscv_v_vstate_dirty(struct pt_regs *regs)
{
- regs->status = (regs->status & ~SR_VS) | SR_VS_DIRTY;
+ regs->status = __riscv_v_vstate_or(regs->status, DIRTY);
}

static inline void riscv_v_vstate_off(struct pt_regs *regs)
{
- regs->status = (regs->status & ~SR_VS) | SR_VS_OFF;
+ regs->status = __riscv_v_vstate_or(regs->status, OFF);
}

static inline void riscv_v_vstate_on(struct pt_regs *regs)
{
- regs->status = (regs->status & ~SR_VS) | SR_VS_INITIAL;
+ regs->status = __riscv_v_vstate_or(regs->status, INITIAL);
}

static inline bool riscv_v_vstate_query(struct pt_regs *regs)
{
- return (regs->status & SR_VS) != 0;
+ return !__riscv_v_vstate_check(regs->status, OFF);
}

static __always_inline void riscv_v_enable(void)
{
- csr_set(CSR_SSTATUS, SR_VS);
+ if (has_xtheadvector())
+ csr_set(CSR_SSTATUS, SR_VS_THEAD);
+ else
+ csr_set(CSR_SSTATUS, SR_VS);
}

static __always_inline void riscv_v_disable(void)
{
- csr_clear(CSR_SSTATUS, SR_VS);
+ if (has_xtheadvector())
+ csr_clear(CSR_SSTATUS, SR_VS_THEAD);
+ else
+ csr_clear(CSR_SSTATUS, SR_VS);
}

static __always_inline void __vstate_csr_save(struct __riscv_v_ext_state *dest)
@@ -81,10 +125,49 @@ static __always_inline void __vstate_csr_save(struct __riscv_v_ext_state *dest)
"csrr %0, " __stringify(CSR_VSTART) "\n\t"
"csrr %1, " __stringify(CSR_VTYPE) "\n\t"
"csrr %2, " __stringify(CSR_VL) "\n\t"
- "csrr %3, " __stringify(CSR_VCSR) "\n\t"
- "csrr %4, " __stringify(CSR_VLENB) "\n\t"
: "=r" (dest->vstart), "=r" (dest->vtype), "=r" (dest->vl),
- "=r" (dest->vcsr), "=r" (dest->vlenb) : :);
+ "=r" (dest->vcsr) : :);
+
+ if (has_xtheadvector()) {
+ u32 tmp_vcsr;
+ bool restore_fpu = false;
+ unsigned long status = csr_read(CSR_SSTATUS);
+
+ /*
+ * CSR_VCSR is defined as
+ * [2:1] - vxrm[1:0]
+ * [0] - vxsat
+ * The earlier vector spec implemented by T-Head uses separate
+ * registers for the same bit-elements, so just combine those
+ * into the existing output field.
+ *
+ * Additionally T-Head cores need FS to be enabled when accessing
+ * the VXRM and VXSAT CSRs, otherwise ending in illegal instructions.
+ * Though the cores do not implement the VXRM and VXSAT fields in the
+ * FCSR CSR that vector-0.7.1 specifies.
+ */
+ if ((status & SR_FS) == SR_FS_OFF) {
+ csr_set(CSR_SSTATUS, (status & ~SR_FS) | SR_FS_CLEAN);
+ restore_fpu = true;
+ }
+
+ asm volatile (
+ "csrr %[tmp_vcsr], " __stringify(VCSR_VXRM) "\n\t"
+ "slliw %[vcsr], %[tmp_vcsr], " __stringify(VCSR_VXRM_SHIFT) "\n\t"
+ "csrr %[tmp_vcsr], " __stringify(VCSR_VXSAT) "\n\t"
+ "or %[vcsr], %[vcsr], %[tmp_vcsr]\n\t"
+ : [vcsr] "=r" (dest->vcsr), [tmp_vcsr] "=&r" (tmp_vcsr));
+
+ dest->vlenb = riscv_v_vsize / 32;
+
+ if (restore_fpu)
+ csr_set(CSR_SSTATUS, status);
+ } else {
+ asm volatile (
+ "csrr %[vcsr], " __stringify(CSR_VCSR) "\n\t"
+ "csrr %[vlenb], " __stringify(CSR_VLENB) "\n\t"
+ : [vcsr] "=r" (dest->vcsr), [vlenb] "=r" (dest->vlenb));
+ }
}

static __always_inline void __vstate_csr_restore(struct __riscv_v_ext_state *src)
@@ -95,9 +178,37 @@ static __always_inline void __vstate_csr_restore(struct __riscv_v_ext_state *src
"vsetvl x0, %2, %1\n\t"
".option pop\n\t"
"csrw " __stringify(CSR_VSTART) ", %0\n\t"
- "csrw " __stringify(CSR_VCSR) ", %3\n\t"
- : : "r" (src->vstart), "r" (src->vtype), "r" (src->vl),
- "r" (src->vcsr) :);
+ : : "r" (src->vstart), "r" (src->vtype), "r" (src->vl));
+
+ if (has_xtheadvector()) {
+ u32 tmp_vcsr;
+ bool restore_fpu = false;
+ unsigned long status = csr_read(CSR_SSTATUS);
+
+ /*
+ * Similar to __vstate_csr_save above, restore values for the
+ * separate VXRM and VXSAT CSRs from the vcsr variable.
+ */
+ if ((status & SR_FS) == SR_FS_OFF) {
+ csr_set(CSR_SSTATUS, (status & ~SR_FS) | SR_FS_CLEAN);
+ restore_fpu = true;
+ }
+
+ asm volatile (
+ "srliw %[tmp_vcsr], %[vcsr], " __stringify(VCSR_VXRM_SHIFT) "\n\t"
+ "andi %[tmp_vcsr], %[tmp_vcsr], " __stringify(VCSR_VXRM_MASK) "\n\t"
+ "csrw " __stringify(VCSR_VXRM) ", %[tmp_vcsr]\n\t"
+ "andi %[tmp_vcsr], %[vcsr], " __stringify(VCSR_VXSAT_MASK) "\n\t"
+ "csrw " __stringify(VCSR_VXSAT) ", %[tmp_vcsr]\n\t"
+ : [tmp_vcsr] "=&r" (tmp_vcsr) : [vcsr] "r" (src->vcsr));
+
+ if (restore_fpu)
+ csr_set(CSR_SSTATUS, status);
+ } else {
+ asm volatile (
+ "csrw " __stringify(CSR_VCSR) ", %[vcsr]\n\t"
+ : : [vcsr] "r" (src->vcsr));
+ }
}

static inline void __riscv_v_vstate_save(struct __riscv_v_ext_state *save_to,
@@ -107,19 +218,33 @@ static inline void __riscv_v_vstate_save(struct __riscv_v_ext_state *save_to,

riscv_v_enable();
__vstate_csr_save(save_to);
- asm volatile (
- ".option push\n\t"
- ".option arch, +v\n\t"
- "vsetvli %0, x0, e8, m8, ta, ma\n\t"
- "vse8.v v0, (%1)\n\t"
- "add %1, %1, %0\n\t"
- "vse8.v v8, (%1)\n\t"
- "add %1, %1, %0\n\t"
- "vse8.v v16, (%1)\n\t"
- "add %1, %1, %0\n\t"
- "vse8.v v24, (%1)\n\t"
- ".option pop\n\t"
- : "=&r" (vl) : "r" (datap) : "memory");
+ if (has_xtheadvector()) {
+ asm volatile (
+ "mv t0, %0\n\t"
+ THEAD_VSETVLI_T4X0E8M8D1
+ THEAD_VSB_V_V0T0
+ "add t0, t0, t4\n\t"
+ THEAD_VSB_V_V0T0
+ "add t0, t0, t4\n\t"
+ THEAD_VSB_V_V0T0
+ "add t0, t0, t4\n\t"
+ THEAD_VSB_V_V0T0
+ : : "r" (datap) : "memory", "t0", "t4");
+ } else {
+ asm volatile (
+ ".option push\n\t"
+ ".option arch, +v\n\t"
+ "vsetvli %0, x0, e8, m8, ta, ma\n\t"
+ "vse8.v v0, (%1)\n\t"
+ "add %1, %1, %0\n\t"
+ "vse8.v v8, (%1)\n\t"
+ "add %1, %1, %0\n\t"
+ "vse8.v v16, (%1)\n\t"
+ "add %1, %1, %0\n\t"
+ "vse8.v v24, (%1)\n\t"
+ ".option pop\n\t"
+ : "=&r" (vl) : "r" (datap) : "memory");
+ }
riscv_v_disable();
}

@@ -129,55 +254,77 @@ static inline void __riscv_v_vstate_restore(struct __riscv_v_ext_state *restore_
unsigned long vl;

riscv_v_enable();
- asm volatile (
- ".option push\n\t"
- ".option arch, +v\n\t"
- "vsetvli %0, x0, e8, m8, ta, ma\n\t"
- "vle8.v v0, (%1)\n\t"
- "add %1, %1, %0\n\t"
- "vle8.v v8, (%1)\n\t"
- "add %1, %1, %0\n\t"
- "vle8.v v16, (%1)\n\t"
- "add %1, %1, %0\n\t"
- "vle8.v v24, (%1)\n\t"
- ".option pop\n\t"
- : "=&r" (vl) : "r" (datap) : "memory");
+ if (has_xtheadvector()) {
+ asm volatile (
+ "mv t0, %0\n\t"
+ THEAD_VSETVLI_T4X0E8M8D1
+ THEAD_VLB_V_V0T0
+ "add t0, t0, t4\n\t"
+ THEAD_VLB_V_V0T0
+ "add t0, t0, t4\n\t"
+ THEAD_VLB_V_V0T0
+ "add t0, t0, t4\n\t"
+ THEAD_VLB_V_V0T0
+ : : "r" (datap) : "memory", "t0", "t4");
+ } else {
+ asm volatile (
+ ".option push\n\t"
+ ".option arch, +v\n\t"
+ "vsetvli %0, x0, e8, m8, ta, ma\n\t"
+ "vle8.v v0, (%1)\n\t"
+ "add %1, %1, %0\n\t"
+ "vle8.v v8, (%1)\n\t"
+ "add %1, %1, %0\n\t"
+ "vle8.v v16, (%1)\n\t"
+ "add %1, %1, %0\n\t"
+ "vle8.v v24, (%1)\n\t"
+ ".option pop\n\t"
+ : "=&r" (vl) : "r" (datap) : "memory");
+ }
__vstate_csr_restore(restore_from);
riscv_v_disable();
}

static inline void __riscv_v_vstate_discard(void)
{
- unsigned long vl, vtype_inval = 1UL << (BITS_PER_LONG - 1);
+ unsigned long vtype_inval = 1UL << (BITS_PER_LONG - 1);

riscv_v_enable();
+ if (has_xtheadvector())
+ asm volatile (THEAD_VSETVLI_X0X0E8M8D1);
+ else
+ asm volatile (
+ ".option push\n\t"
+ ".option arch, +v\n\t"
+ "vsetvli x0, x0, e8, m8, ta, ma\n\t"
+ ".option pop\n\t");
+
asm volatile (
".option push\n\t"
".option arch, +v\n\t"
- "vsetvli %0, x0, e8, m8, ta, ma\n\t"
"vmv.v.i v0, -1\n\t"
"vmv.v.i v8, -1\n\t"
"vmv.v.i v16, -1\n\t"
"vmv.v.i v24, -1\n\t"
- "vsetvl %0, x0, %1\n\t"
+ "vsetvl x0, x0, %0\n\t"
".option pop\n\t"
- : "=&r" (vl) : "r" (vtype_inval) : "memory");
+ : : "r" (vtype_inval));
+
riscv_v_disable();
}

static inline void riscv_v_vstate_discard(struct pt_regs *regs)
{
- if ((regs->status & SR_VS) == SR_VS_OFF)
- return;
-
- __riscv_v_vstate_discard();
- __riscv_v_vstate_dirty(regs);
+ if (riscv_v_vstate_query(regs)) {
+ __riscv_v_vstate_discard();
+ __riscv_v_vstate_dirty(regs);
+ }
}

static inline void riscv_v_vstate_save(struct __riscv_v_ext_state *vstate,
struct pt_regs *regs)
{
- if ((regs->status & SR_VS) == SR_VS_DIRTY) {
+ if (__riscv_v_vstate_check(regs->status, DIRTY)) {
__riscv_v_vstate_save(vstate, vstate->datap);
__riscv_v_vstate_clean(regs);
}
@@ -186,7 +333,7 @@ static inline void riscv_v_vstate_save(struct __riscv_v_ext_state *vstate,
static inline void riscv_v_vstate_restore(struct __riscv_v_ext_state *vstate,
struct pt_regs *regs)
{
- if ((regs->status & SR_VS) != SR_VS_OFF) {
+ if (riscv_v_vstate_query(regs)) {
__riscv_v_vstate_restore(vstate, vstate->datap);
__riscv_v_vstate_clean(regs);
}
@@ -195,7 +342,7 @@ static inline void riscv_v_vstate_restore(struct __riscv_v_ext_state *vstate,
static inline void riscv_v_vstate_set_restore(struct task_struct *task,
struct pt_regs *regs)
{
- if ((regs->status & SR_VS) != SR_VS_OFF) {
+ if (riscv_v_vstate_query(regs)) {
set_tsk_thread_flag(task, TIF_RISCV_V_DEFER_RESTORE);
riscv_v_vstate_on(regs);
}
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index 077be4ab1f9a..180f7eae9086 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -789,7 +789,7 @@ void __init riscv_fill_hwcap(void)
elf_hwcap &= ~COMPAT_HWCAP_ISA_F;
}

- if (elf_hwcap & COMPAT_HWCAP_ISA_V) {
+ if (elf_hwcap & COMPAT_HWCAP_ISA_V || has_xtheadvector_no_alternatives()) {
riscv_v_setup_vsize();
/*
* ISA string in device tree might have 'v' flag, but
diff --git a/arch/riscv/kernel/kernel_mode_vector.c b/arch/riscv/kernel/kernel_mode_vector.c
index 6afe80c7f03a..99972a48e86b 100644
--- a/arch/riscv/kernel/kernel_mode_vector.c
+++ b/arch/riscv/kernel/kernel_mode_vector.c
@@ -143,7 +143,7 @@ static int riscv_v_start_kernel_context(bool *is_nested)

/* Transfer the ownership of V from user to kernel, then save */
riscv_v_start(RISCV_PREEMPT_V | RISCV_PREEMPT_V_DIRTY);
- if ((task_pt_regs(current)->status & SR_VS) == SR_VS_DIRTY) {
+ if (__riscv_v_vstate_check(task_pt_regs(current)->status, DIRTY)) {
uvstate = &current->thread.vstate;
__riscv_v_vstate_save(uvstate, uvstate->datap);
}
@@ -160,7 +160,7 @@ asmlinkage void riscv_v_context_nesting_start(struct pt_regs *regs)
return;

depth = riscv_v_ctx_get_depth();
- if (depth == 0 && (regs->status & SR_VS) == SR_VS_DIRTY)
+ if (depth == 0 && __riscv_v_vstate_check(regs->status, DIRTY))
riscv_preempt_v_set_dirty();

riscv_v_ctx_depth_inc();
@@ -208,7 +208,7 @@ void kernel_vector_begin(void)
{
bool nested = false;

- if (WARN_ON(!has_vector()))
+ if (WARN_ON(!(has_vector() || has_xtheadvector())))
return;

BUG_ON(!may_use_simd());
@@ -236,7 +236,7 @@ EXPORT_SYMBOL_GPL(kernel_vector_begin);
*/
void kernel_vector_end(void)
{
- if (WARN_ON(!has_vector()))
+ if (WARN_ON(!(has_vector() || has_xtheadvector())))
return;

riscv_v_disable();
diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c
index e4bc61c4e58a..191023decd16 100644
--- a/arch/riscv/kernel/process.c
+++ b/arch/riscv/kernel/process.c
@@ -176,7 +176,7 @@ void flush_thread(void)
void arch_release_task_struct(struct task_struct *tsk)
{
/* Free the vector context of datap. */
- if (has_vector())
+ if (has_vector() || has_xtheadvector())
riscv_v_thread_free(tsk);
}

@@ -222,7 +222,7 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
p->thread.s[0] = 0;
}
p->thread.riscv_v_flags = 0;
- if (has_vector())
+ if (has_vector() || has_xtheadvector())
riscv_v_thread_alloc(p);
p->thread.ra = (unsigned long)ret_from_fork;
p->thread.sp = (unsigned long)childregs; /* kernel sp */
diff --git a/arch/riscv/kernel/signal.c b/arch/riscv/kernel/signal.c
index 5a2edd7f027e..1d5e4b3ca9e1 100644
--- a/arch/riscv/kernel/signal.c
+++ b/arch/riscv/kernel/signal.c
@@ -189,7 +189,7 @@ static long restore_sigcontext(struct pt_regs *regs,

return 0;
case RISCV_V_MAGIC:
- if (!has_vector() || !riscv_v_vstate_query(regs) ||
+ if (!(has_vector() || has_xtheadvector()) || !riscv_v_vstate_query(regs) ||
size != riscv_v_sc_size)
return -EINVAL;

@@ -211,7 +211,7 @@ static size_t get_rt_frame_size(bool cal_all)

frame_size = sizeof(*frame);

- if (has_vector()) {
+ if (has_vector() || has_xtheadvector()) {
if (cal_all || riscv_v_vstate_query(task_pt_regs(current)))
total_context_size += riscv_v_sc_size;
}
@@ -284,7 +284,7 @@ static long setup_sigcontext(struct rt_sigframe __user *frame,
if (has_fpu())
err |= save_fp_state(regs, &sc->sc_fpregs);
/* Save the vector state. */
- if (has_vector() && riscv_v_vstate_query(regs))
+ if ((has_vector() || has_xtheadvector()) && riscv_v_vstate_query(regs))
err |= save_v_state(regs, (void __user **)&sc_ext_ptr);
/* Write zero to fp-reserved space and check it on restore_sigcontext */
err |= __put_user(0, &sc->sc_extdesc.reserved);
diff --git a/arch/riscv/kernel/vector.c b/arch/riscv/kernel/vector.c
index 3ba2f2432483..83126995f61a 100644
--- a/arch/riscv/kernel/vector.c
+++ b/arch/riscv/kernel/vector.c
@@ -63,7 +63,7 @@ int riscv_v_setup_vsize(void)

void __init riscv_v_setup_ctx_cache(void)
{
- if (!has_vector())
+ if (!(has_vector() || has_xtheadvector()))
return;

riscv_v_user_cachep = kmem_cache_create_usercopy("riscv_vector_ctx",
@@ -184,7 +184,8 @@ bool riscv_v_first_use_handler(struct pt_regs *regs)
u32 insn = (u32)regs->badaddr;

/* Do not handle if V is not supported, or disabled */
- if (!(ELF_HWCAP & COMPAT_HWCAP_ISA_V))
+ if (!(ELF_HWCAP & COMPAT_HWCAP_ISA_V) &&
+ !(has_xtheadvector() && riscv_v_vstate_ctrl_user_allowed()))
return false;

/* If V has been enabled then it is not the first-use trap */
@@ -223,7 +224,7 @@ void riscv_v_vstate_ctrl_init(struct task_struct *tsk)
bool inherit;
int cur, next;

- if (!has_vector())
+ if (!(has_vector() || has_xtheadvector()))
return;

next = riscv_v_ctrl_get_next(tsk);
@@ -245,7 +246,7 @@ void riscv_v_vstate_ctrl_init(struct task_struct *tsk)

long riscv_v_vstate_ctrl_get_current(void)
{
- if (!has_vector())
+ if (!(has_vector() || has_xtheadvector()))
return -EINVAL;

return current->thread.vstate_ctrl & PR_RISCV_V_VSTATE_CTRL_MASK;
@@ -256,7 +257,7 @@ long riscv_v_vstate_ctrl_set_current(unsigned long arg)
bool inherit;
int cur, next;

- if (!has_vector())
+ if (!(has_vector() || has_xtheadvector()))
return -EINVAL;

if (arg & ~PR_RISCV_V_VSTATE_CTRL_MASK)
@@ -306,7 +307,7 @@ static struct ctl_table riscv_v_default_vstate_table[] = {

static int __init riscv_v_sysctl_init(void)
{
- if (has_vector())
+ if (has_vector() || has_xtheadvector())
if (!register_sysctl("abi", riscv_v_default_vstate_table))
return -EINVAL;
return 0;

--
2.44.0


2024-06-11 15:59:37

by Evan Green

[permalink] [raw]
Subject: Re: [PATCH v2 11/13] riscv: hwprobe: Document thead vendor extensions and xtheadvector extension

On Mon, Jun 10, 2024 at 3:57 PM Charlie Jenkins <[email protected]> wrote:
>
> Document support for thead vendor extensions using the key
> RISCV_HWPROBE_KEY_VENDOR_EXT_THEAD_0 and xtheadvector extension using
> the key RISCV_HWPROBE_VENDOR_EXT_XTHEADVECTOR.
>
> Signed-off-by: Charlie Jenkins <[email protected]>
> Reviewed-by: Evan Green <[email protected]>
> ---
> Documentation/arch/riscv/hwprobe.rst | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
> diff --git a/Documentation/arch/riscv/hwprobe.rst b/Documentation/arch/riscv/hwprobe.rst
> index 204cd4433af5..9c0ef8c57228 100644
> --- a/Documentation/arch/riscv/hwprobe.rst
> +++ b/Documentation/arch/riscv/hwprobe.rst
> @@ -214,3 +214,13 @@ The following keys are defined:
>
> * :c:macro:`RISCV_HWPROBE_KEY_ZICBOZ_BLOCK_SIZE`: An unsigned int which
> represents the size of the Zicboz block in bytes.
> +
> +* :c:macro:`RISCV_HWPROBE_KEY_VENDOR_EXT_THEAD_0`: A bitmask containing the

Our recent snafoo with CPUPERF_0 popped into my memory
when reading this. Does this work properly with the WHICH_CPUS flag?
Specifically, we need hwprobe_key_is_bitmask() to return true for this
key since it's a bitmask.

2024-06-11 19:47:27

by Charlie Jenkins

[permalink] [raw]
Subject: Re: [PATCH v2 11/13] riscv: hwprobe: Document thead vendor extensions and xtheadvector extension

On Tue, Jun 11, 2024 at 08:58:37AM -0700, Evan Green wrote:
> On Mon, Jun 10, 2024 at 3:57 PM Charlie Jenkins <[email protected]> wrote:
> >
> > Document support for thead vendor extensions using the key
> > RISCV_HWPROBE_KEY_VENDOR_EXT_THEAD_0 and xtheadvector extension using
> > the key RISCV_HWPROBE_VENDOR_EXT_XTHEADVECTOR.
> >
> > Signed-off-by: Charlie Jenkins <[email protected]>
> > Reviewed-by: Evan Green <[email protected]>
> > ---
> > Documentation/arch/riscv/hwprobe.rst | 10 ++++++++++
> > 1 file changed, 10 insertions(+)
> >
> > diff --git a/Documentation/arch/riscv/hwprobe.rst b/Documentation/arch/riscv/hwprobe.rst
> > index 204cd4433af5..9c0ef8c57228 100644
> > --- a/Documentation/arch/riscv/hwprobe.rst
> > +++ b/Documentation/arch/riscv/hwprobe.rst
> > @@ -214,3 +214,13 @@ The following keys are defined:
> >
> > * :c:macro:`RISCV_HWPROBE_KEY_ZICBOZ_BLOCK_SIZE`: An unsigned int which
> > represents the size of the Zicboz block in bytes.
> > +
> > +* :c:macro:`RISCV_HWPROBE_KEY_VENDOR_EXT_THEAD_0`: A bitmask containing the
>
> Our recent snafoo with CPUPERF_0 popped into my memory
> when reading this. Does this work properly with the WHICH_CPUS flag?
> Specifically, we need hwprobe_key_is_bitmask() to return true for this
> key since it's a bitmask.

Hmm yes I need to add that. Thank you.

- Charlie


2024-06-13 14:35:32

by Conor Dooley

[permalink] [raw]
Subject: Re: [PATCH v2 02/13] dt-bindings: cpus: add a thead vlen register length property

On Mon, Jun 10, 2024 at 03:56:39PM -0700, Charlie Jenkins wrote:
> Add a property analogous to the vlenb CSR so that software can detect
> the vector length of each CPU prior to it being brought online.
> Currently software has to assume that the vector length read from the
> boot CPU applies to all possible CPUs. On T-Head CPUs implementing
> pre-ratification vector, reading the th.vlenb CSR may produce an illegal
> instruction trap, so this property is required on such systems.
>
> Signed-off-by: Charlie Jenkins <[email protected]>

Reviewed-by: Conor Dooley <[email protected]>


Attachments:
(No filename) (611.00 B)
signature.asc (235.00 B)
Download all attachments

2024-06-13 14:36:18

by Conor Dooley

[permalink] [raw]
Subject: Re: [PATCH v2 03/13] riscv: dts: allwinner: Add xtheadvector to the D1/D1s devicetree

On Mon, Jun 10, 2024 at 03:56:40PM -0700, Charlie Jenkins wrote:
> The D1/D1s SoCs support xtheadvector so it can be included in the
> devicetree. Also include vlenb for the cpu.
>
> Signed-off-by: Charlie Jenkins <[email protected]>

Reviewed-by: Conor Dooley <[email protected]>

> ---
> arch/riscv/boot/dts/allwinner/sun20i-d1s.dtsi | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/arch/riscv/boot/dts/allwinner/sun20i-d1s.dtsi b/arch/riscv/boot/dts/allwinner/sun20i-d1s.dtsi
> index 64c3c2e6cbe0..6367112e614a 100644
> --- a/arch/riscv/boot/dts/allwinner/sun20i-d1s.dtsi
> +++ b/arch/riscv/boot/dts/allwinner/sun20i-d1s.dtsi
> @@ -27,7 +27,8 @@ cpu0: cpu@0 {
> riscv,isa = "rv64imafdc";
> riscv,isa-base = "rv64i";
> riscv,isa-extensions = "i", "m", "a", "f", "d", "c", "zicntr", "zicsr",
> - "zifencei", "zihpm";
> + "zifencei", "zihpm", "xtheadvector";
> + thead,vlenb = <128>;
> #cooling-cells = <2>;
>
> cpu0_intc: interrupt-controller {
>
> --
> 2.44.0
>


Attachments:
(No filename) (1.06 kB)
signature.asc (235.00 B)
Download all attachments

2024-06-13 14:38:51

by Conor Dooley

[permalink] [raw]
Subject: Re: [PATCH v2 08/13] riscv: Add xtheadvector instruction definitions

On Mon, Jun 10, 2024 at 03:56:45PM -0700, Charlie Jenkins wrote:
> xtheadvector uses different encodings than standard vector for
> vsetvli and vector loads/stores. Write the instruction formats to be
> used in assembly code.
>
> Co-developed-by: Heiko Stuebner <[email protected]>
> Signed-off-by: Charlie Jenkins <[email protected]>

Where did Heiko's signoff go?


Attachments:
(No filename) (377.00 B)
signature.asc (235.00 B)
Download all attachments

2024-06-13 14:40:10

by Conor Dooley

[permalink] [raw]
Subject: Re: [PATCH v2 09/13] riscv: vector: Support xtheadvector save/restore

Andy,

On Mon, Jun 10, 2024 at 03:56:46PM -0700, Charlie Jenkins wrote:
> Use alternatives to add support for xtheadvector vector save/restore
> routines.
>
> Signed-off-by: Charlie Jenkins <[email protected]>

Could you review this please?

Cheers,
Conor.

> ---
> arch/riscv/include/asm/csr.h | 6 +
> arch/riscv/include/asm/switch_to.h | 2 +-
> arch/riscv/include/asm/vector.h | 249 ++++++++++++++++++++++++++-------
> arch/riscv/kernel/cpufeature.c | 2 +-
> arch/riscv/kernel/kernel_mode_vector.c | 8 +-
> arch/riscv/kernel/process.c | 4 +-
> arch/riscv/kernel/signal.c | 6 +-
> arch/riscv/kernel/vector.c | 13 +-
> 8 files changed, 222 insertions(+), 68 deletions(-)
>
> diff --git a/arch/riscv/include/asm/csr.h b/arch/riscv/include/asm/csr.h
> index 9086639a3dde..407d4a5687f5 100644
> --- a/arch/riscv/include/asm/csr.h
> +++ b/arch/riscv/include/asm/csr.h
> @@ -30,6 +30,12 @@
> #define SR_VS_CLEAN _AC(0x00000400, UL)
> #define SR_VS_DIRTY _AC(0x00000600, UL)
>
> +#define SR_VS_THEAD _AC(0x01800000, UL) /* xtheadvector Status */
> +#define SR_VS_OFF_THEAD _AC(0x00000000, UL)
> +#define SR_VS_INITIAL_THEAD _AC(0x00800000, UL)
> +#define SR_VS_CLEAN_THEAD _AC(0x01000000, UL)
> +#define SR_VS_DIRTY_THEAD _AC(0x01800000, UL)
> +
> #define SR_XS _AC(0x00018000, UL) /* Extension Status */
> #define SR_XS_OFF _AC(0x00000000, UL)
> #define SR_XS_INITIAL _AC(0x00008000, UL)
> diff --git a/arch/riscv/include/asm/switch_to.h b/arch/riscv/include/asm/switch_to.h
> index 7594df37cc9f..f9cbebe372b8 100644
> --- a/arch/riscv/include/asm/switch_to.h
> +++ b/arch/riscv/include/asm/switch_to.h
> @@ -99,7 +99,7 @@ do { \
> __set_prev_cpu(__prev->thread); \
> if (has_fpu()) \
> __switch_to_fpu(__prev, __next); \
> - if (has_vector()) \
> + if (has_vector() || has_xtheadvector()) \
> __switch_to_vector(__prev, __next); \
> if (switch_to_should_flush_icache(__next)) \
> local_flush_icache_all(); \
> diff --git a/arch/riscv/include/asm/vector.h b/arch/riscv/include/asm/vector.h
> index 731dcd0ed4de..6294dcaabc6a 100644
> --- a/arch/riscv/include/asm/vector.h
> +++ b/arch/riscv/include/asm/vector.h
> @@ -18,6 +18,27 @@
> #include <asm/cpufeature.h>
> #include <asm/csr.h>
> #include <asm/asm.h>
> +#include <asm/vendorid_list.h>
> +#include <asm/vendor_extensions.h>
> +#include <asm/vendor_extensions/thead.h>
> +
> +#define __riscv_v_vstate_or(_val, TYPE) ({ \
> + typeof(_val) _res = _val; \
> + if (has_xtheadvector()) \
> + _res = (_res & ~SR_VS_THEAD) | SR_VS_##TYPE##_THEAD; \
> + else \
> + _res = (_res & ~SR_VS) | SR_VS_##TYPE; \
> + _res; \
> +})
> +
> +#define __riscv_v_vstate_check(_val, TYPE) ({ \
> + bool _res; \
> + if (has_xtheadvector()) \
> + _res = ((_val) & SR_VS_THEAD) == SR_VS_##TYPE##_THEAD; \
> + else \
> + _res = ((_val) & SR_VS) == SR_VS_##TYPE; \
> + _res; \
> +})
>
> extern unsigned long riscv_v_vsize;
> int riscv_v_setup_vsize(void);
> @@ -40,39 +61,62 @@ static __always_inline bool has_vector(void)
> return riscv_has_extension_unlikely(RISCV_ISA_EXT_v);
> }
>
> +static __always_inline bool has_xtheadvector_no_alternatives(void)
> +{
> + if (IS_ENABLED(CONFIG_RISCV_ISA_XTHEADVECTOR))
> + return riscv_isa_vendor_extension_available(THEAD_VENDOR_ID, XTHEADVECTOR);
> + else
> + return false;
> +}
> +
> +static __always_inline bool has_xtheadvector(void)
> +{
> + if (IS_ENABLED(CONFIG_RISCV_ISA_XTHEADVECTOR))
> + return riscv_has_vendor_extension_unlikely(THEAD_VENDOR_ID,
> + RISCV_ISA_VENDOR_EXT_XTHEADVECTOR);
> + else
> + return false;
> +}
> +
> static inline void __riscv_v_vstate_clean(struct pt_regs *regs)
> {
> - regs->status = (regs->status & ~SR_VS) | SR_VS_CLEAN;
> + regs->status = __riscv_v_vstate_or(regs->status, CLEAN);
> }
>
> static inline void __riscv_v_vstate_dirty(struct pt_regs *regs)
> {
> - regs->status = (regs->status & ~SR_VS) | SR_VS_DIRTY;
> + regs->status = __riscv_v_vstate_or(regs->status, DIRTY);
> }
>
> static inline void riscv_v_vstate_off(struct pt_regs *regs)
> {
> - regs->status = (regs->status & ~SR_VS) | SR_VS_OFF;
> + regs->status = __riscv_v_vstate_or(regs->status, OFF);
> }
>
> static inline void riscv_v_vstate_on(struct pt_regs *regs)
> {
> - regs->status = (regs->status & ~SR_VS) | SR_VS_INITIAL;
> + regs->status = __riscv_v_vstate_or(regs->status, INITIAL);
> }
>
> static inline bool riscv_v_vstate_query(struct pt_regs *regs)
> {
> - return (regs->status & SR_VS) != 0;
> + return !__riscv_v_vstate_check(regs->status, OFF);
> }
>
> static __always_inline void riscv_v_enable(void)
> {
> - csr_set(CSR_SSTATUS, SR_VS);
> + if (has_xtheadvector())
> + csr_set(CSR_SSTATUS, SR_VS_THEAD);
> + else
> + csr_set(CSR_SSTATUS, SR_VS);
> }
>
> static __always_inline void riscv_v_disable(void)
> {
> - csr_clear(CSR_SSTATUS, SR_VS);
> + if (has_xtheadvector())
> + csr_clear(CSR_SSTATUS, SR_VS_THEAD);
> + else
> + csr_clear(CSR_SSTATUS, SR_VS);
> }
>
> static __always_inline void __vstate_csr_save(struct __riscv_v_ext_state *dest)
> @@ -81,10 +125,49 @@ static __always_inline void __vstate_csr_save(struct __riscv_v_ext_state *dest)
> "csrr %0, " __stringify(CSR_VSTART) "\n\t"
> "csrr %1, " __stringify(CSR_VTYPE) "\n\t"
> "csrr %2, " __stringify(CSR_VL) "\n\t"
> - "csrr %3, " __stringify(CSR_VCSR) "\n\t"
> - "csrr %4, " __stringify(CSR_VLENB) "\n\t"
> : "=r" (dest->vstart), "=r" (dest->vtype), "=r" (dest->vl),
> - "=r" (dest->vcsr), "=r" (dest->vlenb) : :);
> + "=r" (dest->vcsr) : :);
> +
> + if (has_xtheadvector()) {
> + u32 tmp_vcsr;
> + bool restore_fpu = false;
> + unsigned long status = csr_read(CSR_SSTATUS);
> +
> + /*
> + * CSR_VCSR is defined as
> + * [2:1] - vxrm[1:0]
> + * [0] - vxsat
> + * The earlier vector spec implemented by T-Head uses separate
> + * registers for the same bit-elements, so just combine those
> + * into the existing output field.
> + *
> + * Additionally T-Head cores need FS to be enabled when accessing
> + * the VXRM and VXSAT CSRs, otherwise ending in illegal instructions.
> + * Though the cores do not implement the VXRM and VXSAT fields in the
> + * FCSR CSR that vector-0.7.1 specifies.
> + */
> + if ((status & SR_FS) == SR_FS_OFF) {
> + csr_set(CSR_SSTATUS, (status & ~SR_FS) | SR_FS_CLEAN);
> + restore_fpu = true;
> + }
> +
> + asm volatile (
> + "csrr %[tmp_vcsr], " __stringify(VCSR_VXRM) "\n\t"
> + "slliw %[vcsr], %[tmp_vcsr], " __stringify(VCSR_VXRM_SHIFT) "\n\t"
> + "csrr %[tmp_vcsr], " __stringify(VCSR_VXSAT) "\n\t"
> + "or %[vcsr], %[vcsr], %[tmp_vcsr]\n\t"
> + : [vcsr] "=r" (dest->vcsr), [tmp_vcsr] "=&r" (tmp_vcsr));
> +
> + dest->vlenb = riscv_v_vsize / 32;
> +
> + if (restore_fpu)
> + csr_set(CSR_SSTATUS, status);
> + } else {
> + asm volatile (
> + "csrr %[vcsr], " __stringify(CSR_VCSR) "\n\t"
> + "csrr %[vlenb], " __stringify(CSR_VLENB) "\n\t"
> + : [vcsr] "=r" (dest->vcsr), [vlenb] "=r" (dest->vlenb));
> + }
> }
>
> static __always_inline void __vstate_csr_restore(struct __riscv_v_ext_state *src)
> @@ -95,9 +178,37 @@ static __always_inline void __vstate_csr_restore(struct __riscv_v_ext_state *src
> "vsetvl x0, %2, %1\n\t"
> ".option pop\n\t"
> "csrw " __stringify(CSR_VSTART) ", %0\n\t"
> - "csrw " __stringify(CSR_VCSR) ", %3\n\t"
> - : : "r" (src->vstart), "r" (src->vtype), "r" (src->vl),
> - "r" (src->vcsr) :);
> + : : "r" (src->vstart), "r" (src->vtype), "r" (src->vl));
> +
> + if (has_xtheadvector()) {
> + u32 tmp_vcsr;
> + bool restore_fpu = false;
> + unsigned long status = csr_read(CSR_SSTATUS);
> +
> + /*
> + * Similar to __vstate_csr_save above, restore values for the
> + * separate VXRM and VXSAT CSRs from the vcsr variable.
> + */
> + if ((status & SR_FS) == SR_FS_OFF) {
> + csr_set(CSR_SSTATUS, (status & ~SR_FS) | SR_FS_CLEAN);
> + restore_fpu = true;
> + }
> +
> + asm volatile (
> + "srliw %[tmp_vcsr], %[vcsr], " __stringify(VCSR_VXRM_SHIFT) "\n\t"
> + "andi %[tmp_vcsr], %[tmp_vcsr], " __stringify(VCSR_VXRM_MASK) "\n\t"
> + "csrw " __stringify(VCSR_VXRM) ", %[tmp_vcsr]\n\t"
> + "andi %[tmp_vcsr], %[vcsr], " __stringify(VCSR_VXSAT_MASK) "\n\t"
> + "csrw " __stringify(VCSR_VXSAT) ", %[tmp_vcsr]\n\t"
> + : [tmp_vcsr] "=&r" (tmp_vcsr) : [vcsr] "r" (src->vcsr));
> +
> + if (restore_fpu)
> + csr_set(CSR_SSTATUS, status);
> + } else {
> + asm volatile (
> + "csrw " __stringify(CSR_VCSR) ", %[vcsr]\n\t"
> + : : [vcsr] "r" (src->vcsr));
> + }
> }
>
> static inline void __riscv_v_vstate_save(struct __riscv_v_ext_state *save_to,
> @@ -107,19 +218,33 @@ static inline void __riscv_v_vstate_save(struct __riscv_v_ext_state *save_to,
>
> riscv_v_enable();
> __vstate_csr_save(save_to);
> - asm volatile (
> - ".option push\n\t"
> - ".option arch, +v\n\t"
> - "vsetvli %0, x0, e8, m8, ta, ma\n\t"
> - "vse8.v v0, (%1)\n\t"
> - "add %1, %1, %0\n\t"
> - "vse8.v v8, (%1)\n\t"
> - "add %1, %1, %0\n\t"
> - "vse8.v v16, (%1)\n\t"
> - "add %1, %1, %0\n\t"
> - "vse8.v v24, (%1)\n\t"
> - ".option pop\n\t"
> - : "=&r" (vl) : "r" (datap) : "memory");
> + if (has_xtheadvector()) {
> + asm volatile (
> + "mv t0, %0\n\t"
> + THEAD_VSETVLI_T4X0E8M8D1
> + THEAD_VSB_V_V0T0
> + "add t0, t0, t4\n\t"
> + THEAD_VSB_V_V0T0
> + "add t0, t0, t4\n\t"
> + THEAD_VSB_V_V0T0
> + "add t0, t0, t4\n\t"
> + THEAD_VSB_V_V0T0
> + : : "r" (datap) : "memory", "t0", "t4");
> + } else {
> + asm volatile (
> + ".option push\n\t"
> + ".option arch, +v\n\t"
> + "vsetvli %0, x0, e8, m8, ta, ma\n\t"
> + "vse8.v v0, (%1)\n\t"
> + "add %1, %1, %0\n\t"
> + "vse8.v v8, (%1)\n\t"
> + "add %1, %1, %0\n\t"
> + "vse8.v v16, (%1)\n\t"
> + "add %1, %1, %0\n\t"
> + "vse8.v v24, (%1)\n\t"
> + ".option pop\n\t"
> + : "=&r" (vl) : "r" (datap) : "memory");
> + }
> riscv_v_disable();
> }
>
> @@ -129,55 +254,77 @@ static inline void __riscv_v_vstate_restore(struct __riscv_v_ext_state *restore_
> unsigned long vl;
>
> riscv_v_enable();
> - asm volatile (
> - ".option push\n\t"
> - ".option arch, +v\n\t"
> - "vsetvli %0, x0, e8, m8, ta, ma\n\t"
> - "vle8.v v0, (%1)\n\t"
> - "add %1, %1, %0\n\t"
> - "vle8.v v8, (%1)\n\t"
> - "add %1, %1, %0\n\t"
> - "vle8.v v16, (%1)\n\t"
> - "add %1, %1, %0\n\t"
> - "vle8.v v24, (%1)\n\t"
> - ".option pop\n\t"
> - : "=&r" (vl) : "r" (datap) : "memory");
> + if (has_xtheadvector()) {
> + asm volatile (
> + "mv t0, %0\n\t"
> + THEAD_VSETVLI_T4X0E8M8D1
> + THEAD_VLB_V_V0T0
> + "add t0, t0, t4\n\t"
> + THEAD_VLB_V_V0T0
> + "add t0, t0, t4\n\t"
> + THEAD_VLB_V_V0T0
> + "add t0, t0, t4\n\t"
> + THEAD_VLB_V_V0T0
> + : : "r" (datap) : "memory", "t0", "t4");
> + } else {
> + asm volatile (
> + ".option push\n\t"
> + ".option arch, +v\n\t"
> + "vsetvli %0, x0, e8, m8, ta, ma\n\t"
> + "vle8.v v0, (%1)\n\t"
> + "add %1, %1, %0\n\t"
> + "vle8.v v8, (%1)\n\t"
> + "add %1, %1, %0\n\t"
> + "vle8.v v16, (%1)\n\t"
> + "add %1, %1, %0\n\t"
> + "vle8.v v24, (%1)\n\t"
> + ".option pop\n\t"
> + : "=&r" (vl) : "r" (datap) : "memory");
> + }
> __vstate_csr_restore(restore_from);
> riscv_v_disable();
> }
>
> static inline void __riscv_v_vstate_discard(void)
> {
> - unsigned long vl, vtype_inval = 1UL << (BITS_PER_LONG - 1);
> + unsigned long vtype_inval = 1UL << (BITS_PER_LONG - 1);
>
> riscv_v_enable();
> + if (has_xtheadvector())
> + asm volatile (THEAD_VSETVLI_X0X0E8M8D1);
> + else
> + asm volatile (
> + ".option push\n\t"
> + ".option arch, +v\n\t"
> + "vsetvli x0, x0, e8, m8, ta, ma\n\t"
> + ".option pop\n\t");
> +
> asm volatile (
> ".option push\n\t"
> ".option arch, +v\n\t"
> - "vsetvli %0, x0, e8, m8, ta, ma\n\t"
> "vmv.v.i v0, -1\n\t"
> "vmv.v.i v8, -1\n\t"
> "vmv.v.i v16, -1\n\t"
> "vmv.v.i v24, -1\n\t"
> - "vsetvl %0, x0, %1\n\t"
> + "vsetvl x0, x0, %0\n\t"
> ".option pop\n\t"
> - : "=&r" (vl) : "r" (vtype_inval) : "memory");
> + : : "r" (vtype_inval));
> +
> riscv_v_disable();
> }
>
> static inline void riscv_v_vstate_discard(struct pt_regs *regs)
> {
> - if ((regs->status & SR_VS) == SR_VS_OFF)
> - return;
> -
> - __riscv_v_vstate_discard();
> - __riscv_v_vstate_dirty(regs);
> + if (riscv_v_vstate_query(regs)) {
> + __riscv_v_vstate_discard();
> + __riscv_v_vstate_dirty(regs);
> + }
> }
>
> static inline void riscv_v_vstate_save(struct __riscv_v_ext_state *vstate,
> struct pt_regs *regs)
> {
> - if ((regs->status & SR_VS) == SR_VS_DIRTY) {
> + if (__riscv_v_vstate_check(regs->status, DIRTY)) {
> __riscv_v_vstate_save(vstate, vstate->datap);
> __riscv_v_vstate_clean(regs);
> }
> @@ -186,7 +333,7 @@ static inline void riscv_v_vstate_save(struct __riscv_v_ext_state *vstate,
> static inline void riscv_v_vstate_restore(struct __riscv_v_ext_state *vstate,
> struct pt_regs *regs)
> {
> - if ((regs->status & SR_VS) != SR_VS_OFF) {
> + if (riscv_v_vstate_query(regs)) {
> __riscv_v_vstate_restore(vstate, vstate->datap);
> __riscv_v_vstate_clean(regs);
> }
> @@ -195,7 +342,7 @@ static inline void riscv_v_vstate_restore(struct __riscv_v_ext_state *vstate,
> static inline void riscv_v_vstate_set_restore(struct task_struct *task,
> struct pt_regs *regs)
> {
> - if ((regs->status & SR_VS) != SR_VS_OFF) {
> + if (riscv_v_vstate_query(regs)) {
> set_tsk_thread_flag(task, TIF_RISCV_V_DEFER_RESTORE);
> riscv_v_vstate_on(regs);
> }
> diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
> index 077be4ab1f9a..180f7eae9086 100644
> --- a/arch/riscv/kernel/cpufeature.c
> +++ b/arch/riscv/kernel/cpufeature.c
> @@ -789,7 +789,7 @@ void __init riscv_fill_hwcap(void)
> elf_hwcap &= ~COMPAT_HWCAP_ISA_F;
> }
>
> - if (elf_hwcap & COMPAT_HWCAP_ISA_V) {
> + if (elf_hwcap & COMPAT_HWCAP_ISA_V || has_xtheadvector_no_alternatives()) {
> riscv_v_setup_vsize();
> /*
> * ISA string in device tree might have 'v' flag, but
> diff --git a/arch/riscv/kernel/kernel_mode_vector.c b/arch/riscv/kernel/kernel_mode_vector.c
> index 6afe80c7f03a..99972a48e86b 100644
> --- a/arch/riscv/kernel/kernel_mode_vector.c
> +++ b/arch/riscv/kernel/kernel_mode_vector.c
> @@ -143,7 +143,7 @@ static int riscv_v_start_kernel_context(bool *is_nested)
>
> /* Transfer the ownership of V from user to kernel, then save */
> riscv_v_start(RISCV_PREEMPT_V | RISCV_PREEMPT_V_DIRTY);
> - if ((task_pt_regs(current)->status & SR_VS) == SR_VS_DIRTY) {
> + if (__riscv_v_vstate_check(task_pt_regs(current)->status, DIRTY)) {
> uvstate = &current->thread.vstate;
> __riscv_v_vstate_save(uvstate, uvstate->datap);
> }
> @@ -160,7 +160,7 @@ asmlinkage void riscv_v_context_nesting_start(struct pt_regs *regs)
> return;
>
> depth = riscv_v_ctx_get_depth();
> - if (depth == 0 && (regs->status & SR_VS) == SR_VS_DIRTY)
> + if (depth == 0 && __riscv_v_vstate_check(regs->status, DIRTY))
> riscv_preempt_v_set_dirty();
>
> riscv_v_ctx_depth_inc();
> @@ -208,7 +208,7 @@ void kernel_vector_begin(void)
> {
> bool nested = false;
>
> - if (WARN_ON(!has_vector()))
> + if (WARN_ON(!(has_vector() || has_xtheadvector())))
> return;
>
> BUG_ON(!may_use_simd());
> @@ -236,7 +236,7 @@ EXPORT_SYMBOL_GPL(kernel_vector_begin);
> */
> void kernel_vector_end(void)
> {
> - if (WARN_ON(!has_vector()))
> + if (WARN_ON(!(has_vector() || has_xtheadvector())))
> return;
>
> riscv_v_disable();
> diff --git a/arch/riscv/kernel/process.c b/arch/riscv/kernel/process.c
> index e4bc61c4e58a..191023decd16 100644
> --- a/arch/riscv/kernel/process.c
> +++ b/arch/riscv/kernel/process.c
> @@ -176,7 +176,7 @@ void flush_thread(void)
> void arch_release_task_struct(struct task_struct *tsk)
> {
> /* Free the vector context of datap. */
> - if (has_vector())
> + if (has_vector() || has_xtheadvector())
> riscv_v_thread_free(tsk);
> }
>
> @@ -222,7 +222,7 @@ int copy_thread(struct task_struct *p, const struct kernel_clone_args *args)
> p->thread.s[0] = 0;
> }
> p->thread.riscv_v_flags = 0;
> - if (has_vector())
> + if (has_vector() || has_xtheadvector())
> riscv_v_thread_alloc(p);
> p->thread.ra = (unsigned long)ret_from_fork;
> p->thread.sp = (unsigned long)childregs; /* kernel sp */
> diff --git a/arch/riscv/kernel/signal.c b/arch/riscv/kernel/signal.c
> index 5a2edd7f027e..1d5e4b3ca9e1 100644
> --- a/arch/riscv/kernel/signal.c
> +++ b/arch/riscv/kernel/signal.c
> @@ -189,7 +189,7 @@ static long restore_sigcontext(struct pt_regs *regs,
>
> return 0;
> case RISCV_V_MAGIC:
> - if (!has_vector() || !riscv_v_vstate_query(regs) ||
> + if (!(has_vector() || has_xtheadvector()) || !riscv_v_vstate_query(regs) ||
> size != riscv_v_sc_size)
> return -EINVAL;
>
> @@ -211,7 +211,7 @@ static size_t get_rt_frame_size(bool cal_all)
>
> frame_size = sizeof(*frame);
>
> - if (has_vector()) {
> + if (has_vector() || has_xtheadvector()) {
> if (cal_all || riscv_v_vstate_query(task_pt_regs(current)))
> total_context_size += riscv_v_sc_size;
> }
> @@ -284,7 +284,7 @@ static long setup_sigcontext(struct rt_sigframe __user *frame,
> if (has_fpu())
> err |= save_fp_state(regs, &sc->sc_fpregs);
> /* Save the vector state. */
> - if (has_vector() && riscv_v_vstate_query(regs))
> + if ((has_vector() || has_xtheadvector()) && riscv_v_vstate_query(regs))
> err |= save_v_state(regs, (void __user **)&sc_ext_ptr);
> /* Write zero to fp-reserved space and check it on restore_sigcontext */
> err |= __put_user(0, &sc->sc_extdesc.reserved);
> diff --git a/arch/riscv/kernel/vector.c b/arch/riscv/kernel/vector.c
> index 3ba2f2432483..83126995f61a 100644
> --- a/arch/riscv/kernel/vector.c
> +++ b/arch/riscv/kernel/vector.c
> @@ -63,7 +63,7 @@ int riscv_v_setup_vsize(void)
>
> void __init riscv_v_setup_ctx_cache(void)
> {
> - if (!has_vector())
> + if (!(has_vector() || has_xtheadvector()))
> return;
>
> riscv_v_user_cachep = kmem_cache_create_usercopy("riscv_vector_ctx",
> @@ -184,7 +184,8 @@ bool riscv_v_first_use_handler(struct pt_regs *regs)
> u32 insn = (u32)regs->badaddr;
>
> /* Do not handle if V is not supported, or disabled */
> - if (!(ELF_HWCAP & COMPAT_HWCAP_ISA_V))
> + if (!(ELF_HWCAP & COMPAT_HWCAP_ISA_V) &&
> + !(has_xtheadvector() && riscv_v_vstate_ctrl_user_allowed()))
> return false;
>
> /* If V has been enabled then it is not the first-use trap */
> @@ -223,7 +224,7 @@ void riscv_v_vstate_ctrl_init(struct task_struct *tsk)
> bool inherit;
> int cur, next;
>
> - if (!has_vector())
> + if (!(has_vector() || has_xtheadvector()))
> return;
>
> next = riscv_v_ctrl_get_next(tsk);
> @@ -245,7 +246,7 @@ void riscv_v_vstate_ctrl_init(struct task_struct *tsk)
>
> long riscv_v_vstate_ctrl_get_current(void)
> {
> - if (!has_vector())
> + if (!(has_vector() || has_xtheadvector()))
> return -EINVAL;
>
> return current->thread.vstate_ctrl & PR_RISCV_V_VSTATE_CTRL_MASK;
> @@ -256,7 +257,7 @@ long riscv_v_vstate_ctrl_set_current(unsigned long arg)
> bool inherit;
> int cur, next;
>
> - if (!has_vector())
> + if (!(has_vector() || has_xtheadvector()))
> return -EINVAL;
>
> if (arg & ~PR_RISCV_V_VSTATE_CTRL_MASK)
> @@ -306,7 +307,7 @@ static struct ctl_table riscv_v_default_vstate_table[] = {
>
> static int __init riscv_v_sysctl_init(void)
> {
> - if (has_vector())
> + if (has_vector() || has_xtheadvector())
> if (!register_sysctl("abi", riscv_v_default_vstate_table))
> return -EINVAL;
> return 0;
>
> --
> 2.44.0
>


Attachments:
(No filename) (19.87 kB)
signature.asc (235.00 B)
Download all attachments

2024-06-13 14:42:03

by Conor Dooley

[permalink] [raw]
Subject: Re: [PATCH v2 04/13] riscv: Add thead and xtheadvector as a vendor extension

On Mon, Jun 10, 2024 at 03:56:41PM -0700, Charlie Jenkins wrote:
> Add support to the kernel for THead vendor extensions with the target of
> the new extension xtheadvector.
>
> Signed-off-by: Charlie Jenkins <[email protected]>

Reviewed-by: Conor Dooley <[email protected]>


Attachments:
(No filename) (296.00 B)
signature.asc (235.00 B)
Download all attachments