There are multiple instances in the kernel where we need to include or
exclude particular instructions based on the ISA revision of the target
processor. For MIPS32 / MIPS64, the compiler exports a __mips_isa_rev
define. However, when targeting MIPS I - V, this define is absent. This
leads to each use of __mips_isa_rev having to check that it is defined
first. To simplify this, this series introduces the isa-rev.h header
which always exports MIPS_ISA_REV (the name is changed so as to avoid
confusion with the compiler builtin and to avoid accidentally using the
builtin). All uses of __mips_isa_rev are then replaced with the new
define, removing the check that it is defined.
Applies on v4.16-rc1
Matt Redfearn (4):
MIPS: Introduce isa-rev.h to define MIPS_ISA_REV
MIPS: cpu-features.h: Replace __mips_isa_rev with MIPS_ISA_REV
MIPS: BPF: Replace __mips_isa_rev with MIPS_ISA_REV
MIPS: VDSO: Replace __mips_isa_rev with MIPS_ISA_REV
arch/mips/include/asm/cpu-features.h | 5 +++--
arch/mips/include/asm/isa-rev.h | 24 ++++++++++++++++++++++++
arch/mips/net/bpf_jit_asm.S | 9 +++++----
arch/mips/vdso/elf.S | 10 ++++------
4 files changed, 36 insertions(+), 12 deletions(-)
create mode 100644 arch/mips/include/asm/isa-rev.h
--
2.7.4
Remove the need to check that __mips_isa_rev is defined by using the
newly added MIPS_ISA_REV.
Signed-off-by: Matt Redfearn <[email protected]>
---
arch/mips/include/asm/cpu-features.h | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/mips/include/asm/cpu-features.h b/arch/mips/include/asm/cpu-features.h
index 721b698bfe3c..5f74590e0bea 100644
--- a/arch/mips/include/asm/cpu-features.h
+++ b/arch/mips/include/asm/cpu-features.h
@@ -11,6 +11,7 @@
#include <asm/cpu.h>
#include <asm/cpu-info.h>
+#include <asm/isa-rev.h>
#include <cpu-feature-overrides.h>
/*
@@ -493,7 +494,7 @@
# define cpu_has_perf (cpu_data[0].options & MIPS_CPU_PERF)
#endif
-#if defined(CONFIG_SMP) && defined(__mips_isa_rev) && (__mips_isa_rev >= 6)
+#if defined(CONFIG_SMP) && (MIPS_ISA_REV >= 6)
/*
* Some systems share FTLB RAMs between threads within a core (siblings in
* kernel parlance). This means that FTLB entries may become invalid at almost
@@ -525,7 +526,7 @@
# define cpu_has_shared_ftlb_entries \
(current_cpu_data.options & MIPS_CPU_SHARED_FTLB_ENTRIES)
# endif
-#endif /* SMP && __mips_isa_rev >= 6 */
+#endif /* SMP && MIPS_ISA_REV >= 6 */
#ifndef cpu_has_shared_ftlb_ram
# define cpu_has_shared_ftlb_ram 0
--
2.7.4
There are multiple instances in the kernel where we need to include or
exclude particular instructions based on the ISA revision of the target
processor. For MIPS32 / MIPS64, the compiler exports a __mips_isa_rev
define. However, when targeting MIPS I - V, this define is absent. This
leads to each use of __mips_isa_rev having to check that it is defined
first. To simplify this, introduce the isa-rev.h header which always
exports MIPS_ISA_REV. The name is changed so as to avoid confusion with
the compiler builtin and to avoid accidentally using the builtin.
MIPS_ISA_REV is defined to the compilers builtin if provided, or 0,
which satisfies all current usages.
Suggested-by: Paul Burton <[email protected]>
Signed-off-by: Matt Redfearn <[email protected]>
---
arch/mips/include/asm/isa-rev.h | 24 ++++++++++++++++++++++++
1 file changed, 24 insertions(+)
create mode 100644 arch/mips/include/asm/isa-rev.h
diff --git a/arch/mips/include/asm/isa-rev.h b/arch/mips/include/asm/isa-rev.h
new file mode 100644
index 000000000000..683ea3454dcb
--- /dev/null
+++ b/arch/mips/include/asm/isa-rev.h
@@ -0,0 +1,24 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2018 MIPS Tech, LLC
+ * Author: Matt Redfearn <[email protected]>
+ */
+
+#ifndef __MIPS_ASM_ISA_REV_H__
+#define __MIPS_ASM_ISA_REV_H__
+
+/*
+ * The ISA revision level. This is 0 for MIPS I to V and N for
+ * MIPS{32,64}rN.
+ */
+
+/* If the compiler has defined __mips_isa_rev, believe it. */
+#ifdef __mips_isa_rev
+#define MIPS_ISA_REV __mips_isa_rev
+#else
+/* The compiler hasn't defined the isa rev so assume it's MIPS I - V (0) */
+#define MIPS_ISA_REV 0
+#endif
+
+
+#endif /* __MIPS_ASM_ISA_REV_H__ */
--
2.7.4
Remove the need to check that __mips_isa_rev is defined by using the
newly added MIPS_ISA_REV.
Signed-off-by: Matt Redfearn <[email protected]>
---
arch/mips/net/bpf_jit_asm.S | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/arch/mips/net/bpf_jit_asm.S b/arch/mips/net/bpf_jit_asm.S
index 88a2075305d1..57154c5883b6 100644
--- a/arch/mips/net/bpf_jit_asm.S
+++ b/arch/mips/net/bpf_jit_asm.S
@@ -11,6 +11,7 @@
*/
#include <asm/asm.h>
+#include <asm/isa-rev.h>
#include <asm/regdef.h>
#include "bpf_jit.h"
@@ -65,7 +66,7 @@ FEXPORT(sk_load_word_positive)
lw $r_A, 0(t1)
.set noreorder
#ifdef CONFIG_CPU_LITTLE_ENDIAN
-# if defined(__mips_isa_rev) && (__mips_isa_rev >= 2)
+# if MIPS_ISA_REV >= 2
wsbh t0, $r_A
rotr $r_A, t0, 16
# else
@@ -92,7 +93,7 @@ FEXPORT(sk_load_half_positive)
PTR_ADDU t1, $r_skb_data, offset
lhu $r_A, 0(t1)
#ifdef CONFIG_CPU_LITTLE_ENDIAN
-# if defined(__mips_isa_rev) && (__mips_isa_rev >= 2)
+# if MIPS_ISA_REV >= 2
wsbh $r_A, $r_A
# else
sll t0, $r_A, 8
@@ -170,7 +171,7 @@ FEXPORT(sk_load_byte_positive)
NESTED(bpf_slow_path_word, (6 * SZREG), $r_sp)
bpf_slow_path_common(4)
#ifdef CONFIG_CPU_LITTLE_ENDIAN
-# if defined(__mips_isa_rev) && (__mips_isa_rev >= 2)
+# if MIPS_ISA_REV >= 2
wsbh t0, $r_s0
jr $r_ra
rotr $r_A, t0, 16
@@ -196,7 +197,7 @@ NESTED(bpf_slow_path_word, (6 * SZREG), $r_sp)
NESTED(bpf_slow_path_half, (6 * SZREG), $r_sp)
bpf_slow_path_common(2)
#ifdef CONFIG_CPU_LITTLE_ENDIAN
-# if defined(__mips_isa_rev) && (__mips_isa_rev >= 2)
+# if MIPS_ISA_REV >= 2
jr $r_ra
wsbh $r_A, $r_s0
# else
--
2.7.4
Remove the need to check that __mips_isa_rev is defined by using the
newly added MIPS_ISA_REV.
Signed-off-by: Matt Redfearn <[email protected]>
---
arch/mips/vdso/elf.S | 10 ++++------
1 file changed, 4 insertions(+), 6 deletions(-)
diff --git a/arch/mips/vdso/elf.S b/arch/mips/vdso/elf.S
index be37bbb1f061..428a1917afc6 100644
--- a/arch/mips/vdso/elf.S
+++ b/arch/mips/vdso/elf.S
@@ -10,6 +10,8 @@
#include "vdso.h"
+#include <asm/isa-rev.h>
+
#include <linux/elfnote.h>
#include <linux/version.h>
@@ -40,11 +42,7 @@ __mips_abiflags:
.byte __mips /* isa_level */
/* isa_rev */
-#ifdef __mips_isa_rev
- .byte __mips_isa_rev
-#else
- .byte 0
-#endif
+ .byte MIPS_ISA_REV
/* gpr_size */
#ifdef __mips64
@@ -54,7 +52,7 @@ __mips_abiflags:
#endif
/* cpr1_size */
-#if (defined(__mips_isa_rev) && __mips_isa_rev >= 6) || defined(__mips64)
+#if (MIPS_ISA_REV >= 6) || defined(__mips64)
.byte 2 /* AFL_REG_64 */
#else
.byte 1 /* AFL_REG_32 */
--
2.7.4
On Mon, 26 Feb 2018, Matt Redfearn wrote:
> +/* If the compiler has defined __mips_isa_rev, believe it. */
> +#ifdef __mips_isa_rev
> +#define MIPS_ISA_REV __mips_isa_rev
> +#else
> +/* The compiler hasn't defined the isa rev so assume it's MIPS I - V (0) */
> +#define MIPS_ISA_REV 0
> +#endif
FYI, GCC has this:
/* The ISA revision level. This is 0 for MIPS I to V and N for
MIPS{32,64}rN. */
int mips_isa_rev;
and this:
if (mips_isa < 32)
mips_isa_rev = 0;
else
mips_isa_rev = (mips_isa & 31) + 1;
and then:
if (mips_isa_rev > 0) \
builtin_define_with_int_value ("__mips_isa_rev", \
mips_isa_rev); \
so your proposal looks like the right approach to me. I think we should
have the various target macros documented in the GCC manual.
Reviewed-by: Maciej W. Rozycki <[email protected]>
Maciej
On Mon, Feb 26, 2018 at 05:02:41PM +0000, Matt Redfearn wrote:
> There are multiple instances in the kernel where we need to include or
> exclude particular instructions based on the ISA revision of the target
> processor. For MIPS32 / MIPS64, the compiler exports a __mips_isa_rev
> define. However, when targeting MIPS I - V, this define is absent. This
> leads to each use of __mips_isa_rev having to check that it is defined
> first. To simplify this, this series introduces the isa-rev.h header
> which always exports MIPS_ISA_REV (the name is changed so as to avoid
> confusion with the compiler builtin and to avoid accidentally using the
> builtin). All uses of __mips_isa_rev are then replaced with the new
> define, removing the check that it is defined.
>
> Applies on v4.16-rc1
>
>
> Matt Redfearn (4):
> MIPS: Introduce isa-rev.h to define MIPS_ISA_REV
> MIPS: cpu-features.h: Replace __mips_isa_rev with MIPS_ISA_REV
> MIPS: BPF: Replace __mips_isa_rev with MIPS_ISA_REV
> MIPS: VDSO: Replace __mips_isa_rev with MIPS_ISA_REV
Applied for 4.17,
Thanks
James