[PATCH v2 05/13] riscv: cpufeature: extend riscv_cpufeature_patch_func to all ISA extensions

Jisheng Zhang
2022-12-04T18:00:20Z

make the riscv_cpufeature_patch_func() scan all ISA extensions rather
than limited feature macros.

Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
---
arch/riscv/include/asm/errata_list.h | 9 ++--
arch/riscv/kernel/cpufeature.c | 73 +++++-----------------------
2 files changed, 15 insertions(+), 67 deletions(-)

diff --git a/arch/riscv/include/asm/errata_list.h b/arch/riscv/include/asm/errata_list.h
index 19a771085781..722525f4fc96 100644
--- a/arch/riscv/include/asm/errata_list.h
+++ b/arch/riscv/include/asm/errata_list.h
@@ -6,6 +6,7 @@
#define ASM_ERRATA_LIST_H

#include <asm/alternative.h>
+#include <asm/hwcap.h>
#include <asm/vendorid_list.h>

#ifdef CONFIG_ERRATA_SIFIVE
@@ -20,10 +21,6 @@
#define ERRATA_THEAD_NUMBER 2
#endif

-#define CPUFEATURE_SVPBMT 0
-#define CPUFEATURE_ZICBOM 1
-#define CPUFEATURE_NUMBER 2
-
#ifdef __ASSEMBLY__

#define ALT_INSN_FAULT(x) \
@@ -53,7 +50,7 @@ asm(ALTERNATIVE("sfence.vma %0", "sfence.vma", SIFIVE_VENDOR_ID, \
#define ALT_SVPBMT(_val, prot) \
asm(ALTERNATIVE_2("li %0, 0\t\nnop", \
"li %0, %1\t\nslli %0,%0,%3", 0, \
- CPUFEATURE_SVPBMT, CONFIG_RISCV_ISA_SVPBMT, \
+ RISCV_ISA_EXT_SVPBMT, CONFIG_RISCV_ISA_SVPBMT, \
"li %0, %2\t\nslli %0,%0,%4", THEAD_VENDOR_ID, \
ERRATA_THEAD_PBMT, CONFIG_ERRATA_THEAD_PBMT) \
: "=r"(_val) \
@@ -127,7 +124,7 @@ asm volatile(ALTERNATIVE_2( \
"add a0, a0, %0\n\t" \
"2:\n\t" \
"bltu a0, %2, 3b\n\t" \
- "nop", 0, CPUFEATURE_ZICBOM, CONFIG_RISCV_ISA_ZICBOM, \
+ "nop", 0, RISCV_ISA_EXT_ZICBOM, CONFIG_RISCV_ISA_ZICBOM, \
"mv a0, %1\n\t" \
"j 2f\n\t" \
"3:\n\t" \
diff --git a/arch/riscv/kernel/cpufeature.c b/arch/riscv/kernel/cpufeature.c
index a4d2af67e05c..6244be5cd94a 100644
--- a/arch/riscv/kernel/cpufeature.c
+++ b/arch/riscv/kernel/cpufeature.c
@@ -252,58 +252,11 @@ void __init riscv_fill_hwcap(void)
}

#ifdef CONFIG_RISCV_ALTERNATIVE
-static bool __init_or_module cpufeature_probe_svpbmt(unsigned int stage)
-{
- if (!IS_ENABLED(CONFIG_RISCV_ISA_SVPBMT))
- return false;
-
- if (stage == RISCV_ALTERNATIVES_EARLY_BOOT)
- return false;
-
- return riscv_isa_extension_available(NULL, SVPBMT);
-}
-
-static bool __init_or_module cpufeature_probe_zicbom(unsigned int stage)
-{
- if (!IS_ENABLED(CONFIG_RISCV_ISA_ZICBOM))
- return false;
-
- if (stage == RISCV_ALTERNATIVES_EARLY_BOOT)
- return false;
-
- if (!riscv_isa_extension_available(NULL, ZICBOM))
- return false;
-
- return true;
-}
-
-/*
- * Probe presence of individual extensions.
- *
- * This code may also be executed before kernel relocation, so we cannot use
- * addresses generated by the address-of operator as they won't be valid in
- * this context.
- */
-static u32 __init_or_module cpufeature_probe(unsigned int stage)
-{
- u32 cpu_req_feature = 0;
-
- if (cpufeature_probe_svpbmt(stage))
- cpu_req_feature |= BIT(CPUFEATURE_SVPBMT);
-
- if (cpufeature_probe_zicbom(stage))
- cpu_req_feature |= BIT(CPUFEATURE_ZICBOM);
-
- return cpu_req_feature;
-}
-
void __init_or_module riscv_cpufeature_patch_func(struct alt_entry *begin,
struct alt_entry *end,
unsigned int stage)
{
- u32 cpu_req_feature = cpufeature_probe(stage);
struct alt_entry *alt;
- u32 tmp;

if (stage == RISCV_ALTERNATIVES_EARLY_BOOT)
return;
@@ -311,25 +264,23 @@ void __init_or_module riscv_cpufeature_patch_func(struct alt_entry *begin,
for (alt = begin; alt < end; alt++) {
if (alt->vendor_id != 0)
continue;
- if (alt->errata_id >= CPUFEATURE_NUMBER) {
- WARN(1, "This feature id:%d is not in kernel cpufeature list",
+ if (alt->errata_id >= RISCV_ISA_EXT_MAX) {
+ WARN(1, "This extension id:%d is not in ISA extension list",
alt->errata_id);
continue;
}

- tmp = (1U << alt->errata_id);
- if (cpu_req_feature & tmp) {
- /* do the basic patching */
- patch_text_nosync(alt->old_ptr, alt->alt_ptr,
- alt->alt_len);
+ if (!__riscv_isa_extension_available(NULL, alt->errata_id))
+ continue;

- riscv_alternative_fix_auipc_jalr(alt->old_ptr,
- alt->alt_len,
- alt->old_ptr - alt->alt_ptr);
- riscv_alternative_fix_jal(alt->old_ptr,
- alt->alt_len,
- alt->old_ptr - alt->alt_ptr);
- }
+ /* do the basic patching */
+ patch_text_nosync(alt->old_ptr, alt->alt_ptr, alt->alt_len);
+ riscv_alternative_fix_auipc_jalr(alt->old_ptr,
+ alt->alt_len,
+ alt->old_ptr - alt->alt_ptr);
+ riscv_alternative_fix_jal(alt->old_ptr,
+ alt->alt_len,
+ alt->old_ptr - alt->alt_ptr);
}
}
#endif
--
2.37.2