arm64: Extract feature parsing code from cpu_errata.c

As we detect more architectural features at runtime, it makes
sense to reuse the existing framework whilst avoiding to call
a feature an erratum...

This patch extract the core capability parsing, moves it into
a new file (cpufeature.c), and let the CPU errata detection code
use it.

Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

1 files changed, 4 insertions, 32 deletions

diff --git a/arch/arm64/kernel/cpu_errata.c b/arch/arm64/kernel/cpu_errata.c
index fa62637e63a8..a66f4fa4d541 100644
--- a/arch/arm64/kernel/cpu_errata.c
+++ b/arch/arm64/kernel/cpu_errata.c
@@ -16,8 +16,6 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
-#define pr_fmt(fmt) "alternatives: " fmt
-
 #include <linux/types.h>
 #include <asm/cpu.h>
 #include <asm/cputype.h>
@@ -26,27 +24,11 @@
 #define MIDR_CORTEX_A53 MIDR_CPU_PART(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A53)
 #define MIDR_CORTEX_A57 MIDR_CPU_PART(ARM_CPU_IMP_ARM, ARM_CPU_PART_CORTEX_A57)
 
-/*
- * Add a struct or another datatype to the union below if you need
- * different means to detect an affected CPU.
- */
-struct arm64_cpu_capabilities {
-	const char *desc;
-	u16 capability;
-	bool (*is_affected)(struct arm64_cpu_capabilities *);
-	union {
-		struct {
-			u32 midr_model;
-			u32 midr_range_min, midr_range_max;
-		};
-	};
-};
-
 #define CPU_MODEL_MASK (MIDR_IMPLEMENTOR_MASK | MIDR_PARTNUM_MASK | \
 			MIDR_ARCHITECTURE_MASK)
 
 static bool __maybe_unused
-is_affected_midr_range(struct arm64_cpu_capabilities *entry)
+is_affected_midr_range(const struct arm64_cpu_capabilities *entry)
 {
 	u32 midr = read_cpuid_id();
 
@@ -59,12 +41,12 @@ is_affected_midr_range(struct arm64_cpu_capabilities *entry)
 }
 
 #define MIDR_RANGE(model, min, max) \
-	.is_affected = is_affected_midr_range, \
+	.matches = is_affected_midr_range, \
 	.midr_model = model, \
 	.midr_range_min = min, \
 	.midr_range_max = max
 
-struct arm64_cpu_capabilities arm64_errata[] = {
+const struct arm64_cpu_capabilities arm64_errata[] = {
 #if	defined(CONFIG_ARM64_ERRATUM_826319) || \
 	defined(CONFIG_ARM64_ERRATUM_827319) || \
 	defined(CONFIG_ARM64_ERRATUM_824069)
@@ -97,15 +79,5 @@ struct arm64_cpu_capabilities arm64_errata[] = {
 
 void check_local_cpu_errata(void)
 {
-	struct arm64_cpu_capabilities *cpus = arm64_errata;
-	int i;
-
-	for (i = 0; cpus[i].desc; i++) {
-		if (!cpus[i].is_affected(&cpus[i]))
-			continue;
-
-		if (!cpus_have_cap(cpus[i].capability))
-			pr_info("enabling workaround for %s\n", cpus[i].desc);
-		cpus_set_cap(cpus[i].capability);
-	}
+	check_cpu_capabilities(arm64_errata, "enabling workaround for");
 }