[PATCH 0/4] riscv: some svpbmt fixes

[PATCH 0/4] riscv: some svpbmt fixes

[Heiko Stuebner]

Some additionals comments and notes from autobuilders received
after the series got applied, warranted some changes.

So this is a small collection of cleanups for the svpbmt v10 series.

Heiko Stuebner (4):
  riscv: drop cpufeature_apply_feature tracking variable
  riscv: Improve description for RISCV_ISA_SVPBMT Kconfig symbol
  riscv: make patch-function pointer more generic in
    cpu_manufacturer_info struct
  riscv: fix dependency for t-head errata

 arch/riscv/Kconfig              |  9 +++++++--
 arch/riscv/Kconfig.erratas      |  1 +
 arch/riscv/kernel/alternative.c | 18 +++++++++---------
 arch/riscv/kernel/cpufeature.c  |  5 +----
 4 files changed, 18 insertions(+), 15 deletions(-)

-- 
2.35.1

[PATCH 1/4] riscv: drop cpufeature_apply_feature tracking variable

[Heiko Stuebner]

The variable was tracking which feature patches got applied
but that information was never actually used - and thus resulted
in a warning as well.

Drop the variable.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
---
 arch/riscv/kernel/cpufeature.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index dea3ea19deee..b33564df81e1 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -294,7 +294,6 @@ void __init_or_module riscv_cpufeature_patch_func(struct alt_entry *begin,
 						  unsigned int stage)
 {
 	u32 cpu_req_feature = cpufeature_probe(stage);
-	u32 cpu_apply_feature = 0;
 	struct alt_entry *alt;
 	u32 tmp;
 
@@ -308,10 +307,8 @@ void __init_or_module riscv_cpufeature_patch_func(struct alt_entry *begin,
 		}
 
 		tmp = (1U << alt->errata_id);
-		if (cpu_req_feature & tmp) {
+		if (cpu_req_feature & tmp)
 			patch_text_nosync(alt->old_ptr, alt->alt_ptr, alt->alt_len);
-			cpu_apply_feature |= tmp;
-		}
 	}
 }
 #endif
-- 
2.35.1

[PATCH 2/4] riscv: Improve description for RISCV_ISA_SVPBMT Kconfig symbol

[Heiko Stuebner]

This improves the symbol's description to make it easier for
people to understand what it is about.

Suggested-by: Christoph Hellwig <hch@lst.de>
Suggested-by: Philipp Tomsich <philipp.tomsich@vrull.eu>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
---
 arch/riscv/Kconfig | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 65285b980134..a4b299ad4473 100644
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -356,8 +356,13 @@ config RISCV_ISA_SVPBMT
 	select RISCV_ALTERNATIVE
 	default y
 	help
-	   Adds support to dynamically detect the presence of the SVPBMT extension
-	   (Supervisor-mode: page-based memory types) and enable its usage.
+	   Adds support to dynamically detect the presence of the SVPBMT
+	   ISA-extension (Supervisor-mode: page-based memory types) and
+	   enable its usage.
+
+	   The memory type for a page contains a combination of attributes
+	   that indicate the cacheability, idempotency, and ordering
+	   properties for access to that page.
 
 	   The SVPBMT extension is only available on 64Bit cpus.
 
-- 
2.35.1

[PATCH 3/4] riscv: make patch-function pointer more generic in cpu_manufacturer_info struct

[Heiko Stuebner]

During review the naming of the function-pointer was called
confusing as the vendor id is just one of three inputs for
the patching and indeed it serves no real purpose, as with
recent changes the function pointer is not a static
global element anymore, so drop the "vendor_" prefix.

Suggested-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
---
 arch/riscv/kernel/alternative.c | 18 +++++++++---------
 1 file changed, 9 insertions(+), 9 deletions(-)

diff --git a/arch/riscv/kernel/alternative.c b/arch/riscv/kernel/alternative.c
index c9d0d3c53223..a7d26a00beea 100644
--- a/arch/riscv/kernel/alternative.c
+++ b/arch/riscv/kernel/alternative.c
@@ -20,7 +20,7 @@ struct cpu_manufacturer_info_t {
 	unsigned long vendor_id;
 	unsigned long arch_id;
 	unsigned long imp_id;
-	void (*vendor_patch_func)(struct alt_entry *begin, struct alt_entry *end,
+	void (*patch_func)(struct alt_entry *begin, struct alt_entry *end,
 				  unsigned long archid, unsigned long impid,
 				  unsigned int stage);
 };
@@ -40,16 +40,16 @@ static void __init_or_module riscv_fill_cpu_mfr_info(struct cpu_manufacturer_inf
 	switch (cpu_mfr_info->vendor_id) {
 #ifdef CONFIG_ERRATA_SIFIVE
 	case SIFIVE_VENDOR_ID:
-		cpu_mfr_info->vendor_patch_func = sifive_errata_patch_func;
+		cpu_mfr_info->patch_func = sifive_errata_patch_func;
 		break;
 #endif
 #ifdef CONFIG_ERRATA_THEAD
 	case THEAD_VENDOR_ID:
-		cpu_mfr_info->vendor_patch_func = thead_errata_patch_func;
+		cpu_mfr_info->patch_func = thead_errata_patch_func;
 		break;
 #endif
 	default:
-		cpu_mfr_info->vendor_patch_func = NULL;
+		cpu_mfr_info->patch_func = NULL;
 	}
 }
 
@@ -68,13 +68,13 @@ static void __init_or_module _apply_alternatives(struct alt_entry *begin,
 
 	riscv_cpufeature_patch_func(begin, end, stage);
 
-	if (!cpu_mfr_info.vendor_patch_func)
+	if (!cpu_mfr_info.patch_func)
 		return;
 
-	cpu_mfr_info.vendor_patch_func(begin, end,
-				   cpu_mfr_info.arch_id,
-				   cpu_mfr_info.imp_id,
-				   stage);
+	cpu_mfr_info.patch_func(begin, end,
+				cpu_mfr_info.arch_id,
+				cpu_mfr_info.imp_id,
+				stage);
 }
 
 void __init apply_boot_alternatives(void)
-- 
2.35.1

[PATCH 4/4] riscv: fix dependency for t-head errata

[Heiko Stuebner]

alternatives only work correctly on non-xip-kernels and while the
selected alternative-symbol has the correct dependency the symbol
selecting it also needs that dependency.

So add the missing dependency to the T-Head errata Kconfig symbol.

Reported-by: kernel test robot <yujie.liu@intel.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
---
 arch/riscv/Kconfig.erratas | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/riscv/Kconfig.erratas b/arch/riscv/Kconfig.erratas
index ebfcd5cc6eaf..457ac72c9b36 100644
--- a/arch/riscv/Kconfig.erratas
+++ b/arch/riscv/Kconfig.erratas
@@ -35,6 +35,7 @@ config ERRATA_SIFIVE_CIP_1200
 
 config ERRATA_THEAD
 	bool "T-HEAD errata"
+	depends on !XIP_KERNEL
 	select RISCV_ALTERNATIVE
 	help
 	  All T-HEAD errata Kconfig depend on this Kconfig. Disabling
-- 
2.35.1

Re: [PATCH 4/4] riscv: fix dependency for t-head errata

[Guo Ren]

Reviewed-by: Guo Ren <guoren@kernel.org>

On Thu, May 19, 2022 at 1:03 AM Heiko Stuebner <heiko@sntech.de> wrote:
>
> alternatives only work correctly on non-xip-kernels and while the
> selected alternative-symbol has the correct dependency the symbol
> selecting it also needs that dependency.
>
> So add the missing dependency to the T-Head errata Kconfig symbol.
>
> Reported-by: kernel test robot <yujie.liu@intel.com>
> Signed-off-by: Heiko Stuebner <heiko@sntech.de>
> ---
>  arch/riscv/Kconfig.erratas | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/arch/riscv/Kconfig.erratas b/arch/riscv/Kconfig.erratas
> index ebfcd5cc6eaf..457ac72c9b36 100644
> --- a/arch/riscv/Kconfig.erratas
> +++ b/arch/riscv/Kconfig.erratas
> @@ -35,6 +35,7 @@ config ERRATA_SIFIVE_CIP_1200
>
>  config ERRATA_THEAD
>         bool "T-HEAD errata"
> +       depends on !XIP_KERNEL
>         select RISCV_ALTERNATIVE
>         help
>           All T-HEAD errata Kconfig depend on this Kconfig. Disabling
> --
> 2.35.1
>


-- 
Best Regards
 Guo Ren

ML: https://lore.kernel.org/linux-csky/

Re: [PATCH 0/4] riscv: some svpbmt fixes

[Heiko Stübner]

Am Mittwoch, 18. Mai 2022, 19:02:50 CEST schrieb Heiko Stuebner:
> Some additionals comments and notes from autobuilders received
> after the series got applied, warranted some changes.
> 
> So this is a small collection of cleanups for the svpbmt v10 series.

I've just sent a v2 of this which added another patch onto the series.

See https://lore.kernel.org/r/20220526205646.258337-1-heiko@sntech.de


Heiko

> Heiko Stuebner (4):
>   riscv: drop cpufeature_apply_feature tracking variable
>   riscv: Improve description for RISCV_ISA_SVPBMT Kconfig symbol
>   riscv: make patch-function pointer more generic in
>     cpu_manufacturer_info struct
>   riscv: fix dependency for t-head errata
> 
>  arch/riscv/Kconfig              |  9 +++++++--
>  arch/riscv/Kconfig.erratas      |  1 +
>  arch/riscv/kernel/alternative.c | 18 +++++++++---------
>  arch/riscv/kernel/cpufeature.c  |  5 +----
>  4 files changed, 18 insertions(+), 15 deletions(-)
> 
>