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-rw-r--r--arch/powerpc/include/asm/cpu_has_feature.h56
1 files changed, 56 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/cpu_has_feature.h b/arch/powerpc/include/asm/cpu_has_feature.h
new file mode 100644
index 000000000..727d4b321
--- /dev/null
+++ b/arch/powerpc/include/asm/cpu_has_feature.h
@@ -0,0 +1,56 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __ASM_POWERPC_CPU_HAS_FEATURE_H
+#define __ASM_POWERPC_CPU_HAS_FEATURE_H
+
+#ifndef __ASSEMBLY__
+
+#include <linux/bug.h>
+#include <asm/cputable.h>
+
+static __always_inline bool early_cpu_has_feature(unsigned long feature)
+{
+ return !!((CPU_FTRS_ALWAYS & feature) ||
+ (CPU_FTRS_POSSIBLE & cur_cpu_spec->cpu_features & feature));
+}
+
+#ifdef CONFIG_JUMP_LABEL_FEATURE_CHECKS
+#include <linux/jump_label.h>
+
+#define NUM_CPU_FTR_KEYS BITS_PER_LONG
+
+extern struct static_key_true cpu_feature_keys[NUM_CPU_FTR_KEYS];
+
+static __always_inline bool cpu_has_feature(unsigned long feature)
+{
+ int i;
+
+#ifndef __clang__ /* clang can't cope with this */
+ BUILD_BUG_ON(!__builtin_constant_p(feature));
+#endif
+
+#ifdef CONFIG_JUMP_LABEL_FEATURE_CHECK_DEBUG
+ if (!static_key_initialized) {
+ printk("Warning! cpu_has_feature() used prior to jump label init!\n");
+ dump_stack();
+ return early_cpu_has_feature(feature);
+ }
+#endif
+
+ if (CPU_FTRS_ALWAYS & feature)
+ return true;
+
+ if (!(CPU_FTRS_POSSIBLE & feature))
+ return false;
+
+ i = __builtin_ctzl(feature);
+ return static_branch_likely(&cpu_feature_keys[i]);
+}
+#else
+static __always_inline bool cpu_has_feature(unsigned long feature)
+{
+ return early_cpu_has_feature(feature);
+}
+#endif
+
+#endif /* __ASSEMBLY__ */
+#endif /* __ASM_POWERPC_CPU_HAS_FEATURE_H */