RISC-V: use bit-values instead of numbers to identify
From: Heiko Stuebner <heiko.stuebner@...> Date: Tue, 3 Jan 2023 11:55:25 +0100
Commit-Message
RISC-V cpufeatures are often based on available extensions and maybe even some combination of them. Using a bitfield for the errata-id gives us a simple way to also require a combination of extensions for a specific alternative patch. Signed-off-by: Heiko Stuebner <heiko.stuebner@...>
Patch-Comment
arch/riscv/include/asm/errata_list.h | 6 +++--- arch/riscv/kernel/cpufeature.c | 12 +++++------- 2 files changed, 8 insertions(+), 10 deletions(-)
Statistics
- 8 lines added
- 10 lines removed
Changes
--------------------- arch/riscv/include/asm/errata_list.h ---------------------
index 95e626b7281e..40c9e9c3295b 100644
@@ -22,9 +22,9 @@
#define ERRATA_THEAD_NUMBER 3
#endif
+#define CPUFEATURE_SVPBMT (1 << 0)
+#define CPUFEATURE_ZICBOM (1 << 1)
+#define CPUFEATURE_ZBB (1 << 2)
#define CPUFEATURE_NUMBER 3
#ifdef __ASSEMBLY__
------------------------ arch/riscv/kernel/cpufeature.c ------------------------
index 7bfc6eb9a5cf..8c83bd9d0e22 100644
@@ -350,13 +350,13 @@ static u32 __init_or_module cpufeature_probe(unsigned int stage)
u32 cpu_req_feature = 0;
if (cpufeature_probe_svpbmt(stage))
+ cpu_req_feature |= CPUFEATURE_SVPBMT;
if (cpufeature_probe_zicbom(stage))
+ cpu_req_feature |= CPUFEATURE_ZICBOM;
if (cpufeature_probe_zbb(stage))
+ cpu_req_feature |= CPUFEATURE_ZBB;
return cpu_req_feature;
}
@@ -367,19 +367,17 @@ void __init_or_module riscv_cpufeature_patch_func(struct alt_entry *begin,
{
u32 cpu_req_feature = cpufeature_probe(stage);
struct alt_entry *alt;
for (alt = begin; alt < end; alt++) {
if (alt->vendor_id != 0)
continue;
+ if (alt->errata_id & GENMASK(31, CPUFEATURE_NUMBER)) {
WARN(1, "This feature id:%d is not in kernel cpufeature list",
alt->errata_id);
continue;
}
+ if ((cpu_req_feature & alt->errata_id) == alt->errata_id) {
patch_text_nosync(alt->old_ptr, alt->alt_ptr, alt->alt_len);
riscv_alternative_fix_offsets(alt->old_ptr, alt->alt_len,
alt->old_ptr - alt->alt_ptr);