2023-03-27 16:35:00

by Evan Green

Subject: [PATCH v5 1/6] RISC-V: Move struct riscv_cpuinfo to new header

In preparation for tracking and exposing microarchitectural details to
userspace (like whether or not unaligned accesses are fast), move the
riscv_cpuinfo struct out to its own new cpufeatures.h header. It will
need to be used by more than just cpu.c.

Signed-off-by: Evan Green <[email protected]>
Reviewed-by: Conor Dooley <[email protected]>
Reviewed-by: Heiko Stuebner <[email protected]>
Tested-by: Heiko Stuebner <[email protected]>
---

Changes in v5:
- Added tags

Changes in v3:
- Updated copyright date in cpufeature.h
- Fixed typo in cpufeature.h comment (Conor)

Changes in v2:
- Factored the move of struct riscv_cpuinfo to its own header

arch/riscv/include/asm/cpufeature.h | 21 +++++++++++++++++++++
arch/riscv/kernel/cpu.c | 8 ++------
2 files changed, 23 insertions(+), 6 deletions(-)
create mode 100644 arch/riscv/include/asm/cpufeature.h

diff --git a/arch/riscv/include/asm/cpufeature.h b/arch/riscv/include/asm/cpufeature.h
new file mode 100644
index 000000000000..66ebaae449c8
--- /dev/null
+++ b/arch/riscv/include/asm/cpufeature.h
@@ -0,0 +1,21 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright 2022-2023 Rivos, Inc
+ */
+
+#ifndef _ASM_CPUFEATURE_H
+#define _ASM_CPUFEATURE_H
+
+/*
+ * These are probed via a device_initcall(), via either the SBI or directly
+ * from the corresponding CSRs.
+ */
+struct riscv_cpuinfo {
+ unsigned long mvendorid;
+ unsigned long marchid;
+ unsigned long mimpid;
+};
+
+DECLARE_PER_CPU(struct riscv_cpuinfo, riscv_cpuinfo);
+
+#endif
diff --git a/arch/riscv/kernel/cpu.c b/arch/riscv/kernel/cpu.c
index 8400f0cc9704..dafd0caa4f1d 100644
--- a/arch/riscv/kernel/cpu.c
+++ b/arch/riscv/kernel/cpu.c
@@ -7,6 +7,7 @@
#include <linux/init.h>
#include <linux/seq_file.h>
#include <linux/of.h>
+#include <asm/cpufeature.h>
#include <asm/csr.h>
#include <asm/hwcap.h>
#include <asm/sbi.h>
@@ -70,12 +71,7 @@ int riscv_of_parent_hartid(struct device_node *node, unsigned long *hartid)
return -1;
}

-struct riscv_cpuinfo {
- unsigned long mvendorid;
- unsigned long marchid;
- unsigned long mimpid;
-};
-static DEFINE_PER_CPU(struct riscv_cpuinfo, riscv_cpuinfo);
+DEFINE_PER_CPU(struct riscv_cpuinfo, riscv_cpuinfo);

unsigned long riscv_cached_mvendorid(unsigned int cpu_id)
{
--
2.25.1

2023-04-05 14:02:48

by Paul Walmsley

Subject: Re: [PATCH v5 1/6] RISC-V: Move struct riscv_cpuinfo to new header

On Mon, 27 Mar 2023, Evan Green wrote:

> In preparation for tracking and exposing microarchitectural details to
> userspace (like whether or not unaligned accesses are fast), move the
> riscv_cpuinfo struct out to its own new cpufeatures.h header. It will
> need to be used by more than just cpu.c.
>
> Signed-off-by: Evan Green <[email protected]>
> Reviewed-by: Conor Dooley <[email protected]>
> Reviewed-by: Heiko Stuebner <[email protected]>
> Tested-by: Heiko Stuebner <[email protected]>

Reviewed-by: Paul Walmsley <[email protected]>

- Paul