1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef __ASM_POWERPC_CPU_HAS_FEATURE_H
3 #define __ASM_POWERPC_CPU_HAS_FEATURE_H
4
5 #ifndef __ASSEMBLY__
6
7 #include <linux/bug.h>
8 #include <asm/cputable.h>
9
10 static __always_inline bool early_cpu_has_feature(unsigned long feature)
11 {
12 return !!((CPU_FTRS_ALWAYS & feature) ||
13 (CPU_FTRS_POSSIBLE & cur_cpu_spec->cpu_features & feature));
14 }
15
16 #ifdef CONFIG_JUMP_LABEL_FEATURE_CHECKS
17 #include <linux/jump_label.h>
18
19 #define NUM_CPU_FTR_KEYS BITS_PER_LONG
20
21 extern struct static_key_true cpu_feature_keys[NUM_CPU_FTR_KEYS];
22
23 static __always_inline bool cpu_has_feature(unsigned long feature)
24 {
25 int i;
26
27 BUILD_BUG_ON(!__builtin_constant_p(feature));
28 BUILD_BUG_ON(__builtin_popcountl(feature) > 1);
29
30 #ifdef CONFIG_JUMP_LABEL_FEATURE_CHECK_DEBUG
31 if (!static_key_feature_checks_initialized) {
32 printk("Warning! cpu_has_feature() used prior to jump label init!\n");
33 dump_stack();
34 return early_cpu_has_feature(feature);
35 }
36 #endif
37
38 if (CPU_FTRS_ALWAYS & feature)
39 return true;
40
41 if (!(CPU_FTRS_POSSIBLE & feature))
42 return false;
43
44 i = __builtin_ctzl(feature);
45 return static_branch_likely(&cpu_feature_keys[i]);
46 }
47 #else
48 static __always_inline bool cpu_has_feature(unsigned long feature)
49 {
50 return early_cpu_has_feature(feature);
51 }
52 #endif
53
54 #endif /* __ASSEMBLY__ */
55 #endif /* __ASM_POWERPC_CPU_HAS_FEATURE_H */
56
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.