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authorKevin Hao <haokexin@gmail.com>2016-07-23 14:42:42 +0530
committerMichael Ellerman <mpe@ellerman.id.au>2016-08-01 11:15:06 +1000
commitc12e6f24d4137822d5019c1f78ac65bd27a3447d (patch)
tree7ebc50a5a62a36e89dc90e801da4f00e59633622 /arch/powerpc/include/asm/mmu.h
parent4db7327194dba0cb91f274b0f606785a9ee5108d (diff)
downloadlinux-c12e6f24d4137822d5019c1f78ac65bd27a3447d.tar.bz2
powerpc: Add option to use jump label for mmu_has_feature()
As we just did for CPU features. Signed-off-by: Kevin Hao <haokexin@gmail.com> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/include/asm/mmu.h')
-rw-r--r--arch/powerpc/include/asm/mmu.h38
1 files changed, 38 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/mmu.h b/arch/powerpc/include/asm/mmu.h
index 37f55169df3e..1bf919aafd50 100644
--- a/arch/powerpc/include/asm/mmu.h
+++ b/arch/powerpc/include/asm/mmu.h
@@ -141,6 +141,43 @@ static inline bool early_mmu_has_feature(unsigned long feature)
return !!(MMU_FTRS_POSSIBLE & cur_cpu_spec->mmu_features & feature);
}
+#ifdef CONFIG_JUMP_LABEL_FEATURE_CHECKS
+#include <linux/jump_label.h>
+
+#define NUM_MMU_FTR_KEYS 32
+
+extern struct static_key_true mmu_feature_keys[NUM_MMU_FTR_KEYS];
+
+extern void mmu_feature_keys_init(void);
+
+static __always_inline bool mmu_has_feature(unsigned long feature)
+{
+ int i;
+
+ BUILD_BUG_ON(!__builtin_constant_p(feature));
+
+ if (!(MMU_FTRS_POSSIBLE & feature))
+ return false;
+
+ i = __builtin_ctzl(feature);
+ return static_branch_likely(&mmu_feature_keys[i]);
+}
+
+static inline void mmu_clear_feature(unsigned long feature)
+{
+ int i;
+
+ i = __builtin_ctzl(feature);
+ cur_cpu_spec->mmu_features &= ~feature;
+ static_branch_disable(&mmu_feature_keys[i]);
+}
+#else
+
+static inline void mmu_feature_keys_init(void)
+{
+
+}
+
static inline bool mmu_has_feature(unsigned long feature)
{
return early_mmu_has_feature(feature);
@@ -150,6 +187,7 @@ static inline void mmu_clear_feature(unsigned long feature)
{
cur_cpu_spec->mmu_features &= ~feature;
}
+#endif /* CONFIG_JUMP_LABEL */
extern unsigned int __start___mmu_ftr_fixup, __stop___mmu_ftr_fixup;