2022-10-06 07:36:21

by Jisheng Zhang

Subject: [PATCH 2/8] riscv: cpufeature: detect RISCV_ALTERNATIVES_EARLY_BOOT earlier

Now, the riscv_cpufeature_patch_func() do nothing in the stage of
RISCV_ALTERNATIVES_EARLY_BOOT. We can move the detection of "early
boot" stage earlier.

In following patch, we will make riscv_cpufeature_patch_func() scans
all ISA extensions.

Signed-off-by: Jisheng Zhang <[email protected]>
---
arch/riscv/kernel/cpufeature.c | 3 +++
1 file changed, 3 insertions(+)

diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index 03611b3ef45e..afa54635c180 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -307,6 +307,9 @@ void __init_or_module riscv_cpufeature_patch_func(struct alt_entry *begin,
struct alt_entry *alt;
u32 tmp;

+ if (stage == RISCV_ALTERNATIVES_EARLY_BOOT)
+ return;
+
for (alt = begin; alt < end; alt++) {
if (alt->vendor_id != 0)
continue;
--
2.37.2

2022-10-06 13:50:59

by Andrew Jones

Subject: Re: [PATCH 2/8] riscv: cpufeature: detect RISCV_ALTERNATIVES_EARLY_BOOT earlier

On Thu, Oct 06, 2022 at 03:08:12PM +0800, Jisheng Zhang wrote:
> Now, the riscv_cpufeature_patch_func() do nothing in the stage of
> RISCV_ALTERNATIVES_EARLY_BOOT. We can move the detection of "early
> boot" stage earlier.
>
> In following patch, we will make riscv_cpufeature_patch_func() scans
> all ISA extensions.
>
> Signed-off-by: Jisheng Zhang <[email protected]>
> ---
> arch/riscv/kernel/cpufeature.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
> index 03611b3ef45e..afa54635c180 100644
> --- a/arch/riscv/kernel/cpufeature.c
> +++ b/arch/riscv/kernel/cpufeature.c
> @@ -307,6 +307,9 @@ void __init_or_module riscv_cpufeature_patch_func(struct alt_entry *begin,
> struct alt_entry *alt;
> u32 tmp;
>
> + if (stage == RISCV_ALTERNATIVES_EARLY_BOOT)
> + return;
> +
> for (alt = begin; alt < end; alt++) {
> if (alt->vendor_id != 0)
> continue;
> --
> 2.37.2
>

Reviewed-by: Andrew Jones <[email protected]>

2022-10-07 09:45:13

by Heiko Stuebner

Subject: Re: [PATCH 2/8] riscv: cpufeature: detect RISCV_ALTERNATIVES_EARLY_BOOT earlier

Am Donnerstag, 6. Oktober 2022, 09:08:12 CEST schrieb Jisheng Zhang:
> Now, the riscv_cpufeature_patch_func() do nothing in the stage of
> RISCV_ALTERNATIVES_EARLY_BOOT. We can move the detection of "early
> boot" stage earlier.
>
> In following patch, we will make riscv_cpufeature_patch_func() scans
> all ISA extensions.
>
> Signed-off-by: Jisheng Zhang <[email protected]>
> ---
> arch/riscv/kernel/cpufeature.c | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
> index 03611b3ef45e..afa54635c180 100644
> --- a/arch/riscv/kernel/cpufeature.c
> +++ b/arch/riscv/kernel/cpufeature.c
> @@ -307,6 +307,9 @@ void __init_or_module riscv_cpufeature_patch_func(struct alt_entry *begin,
> struct alt_entry *alt;
> u32 tmp;
>
> + if (stage == RISCV_ALTERNATIVES_EARLY_BOOT)
> + return;
> +

This will work as long as no extension needs early patching,
but we can cross that bridge when this happens :-)

Reviewed-by: Heiko Stuebner <[email protected]>

> for (alt = begin; alt < end; alt++) {
> if (alt->vendor_id != 0)
> continue;
>