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

Jisheng Zhang posted 8 patches 3 years, 6 months ago
There is a newer version of this series
[PATCH 2/8] riscv: cpufeature: detect RISCV_ALTERNATIVES_EARLY_BOOT earlier
Posted by Jisheng Zhang 3 years, 6 months ago
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 <jszhang@kernel.org>
---
 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
Re: [PATCH 2/8] riscv: cpufeature: detect RISCV_ALTERNATIVES_EARLY_BOOT earlier
Posted by Heiko Stübner 3 years, 6 months ago
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 <jszhang@kernel.org>
> ---
>  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 <heiko@sntech.de>

>  	for (alt = begin; alt < end; alt++) {
>  		if (alt->vendor_id != 0)
>  			continue;
>
Re: [PATCH 2/8] riscv: cpufeature: detect RISCV_ALTERNATIVES_EARLY_BOOT earlier
Posted by Andrew Jones 3 years, 6 months ago
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 <jszhang@kernel.org>
> ---
>  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 <ajones@ventanamicro.com>