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https://github.com/torvalds/linux.git
synced 2026-05-25 07:33:19 +02:00
x86/percpu: Clean up <asm/percpu.h> a bit
- Fix misc typos
- There's 4 variants of the same spelling right now:
'per-CPU', 'per CPU', 'percpu' and 'per-cpu'
Standardize on 'per-CPU' only.
- s/makes gcc load
/makes the compiler load
- Instead of:
#ifdef CONFIG_XXXX
#define YYYY FOO
#else
#define YYYY BAR
#endif
Use the slightly more readable form of:
#ifdef CONFIG_XXXX
# define YYYY FOO
#else
# define YYYY BAR
#endif
- Standardize & expand '#else' and '#endif' comments
- Fix comment style
- Capitalize x86 instruction names in comments
No change in code.
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: Uros Bizjak <ubizjak@gmail.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: linux-kernel@vger.kernel.org
This commit is contained in:
Ingo Molnar
parent
47c9dbd2fb
commit
61d73e4f7d
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@ -3,30 +3,30 @@
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#define _ASM_X86_PERCPU_H
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#ifdef CONFIG_X86_64
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#define __percpu_seg gs
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#define __percpu_rel (%rip)
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# define __percpu_seg gs
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# define __percpu_rel (%rip)
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#else
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#define __percpu_seg fs
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#define __percpu_rel
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# define __percpu_seg fs
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# define __percpu_rel
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#endif
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#ifdef __ASSEMBLY__
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#ifdef CONFIG_SMP
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#define __percpu %__percpu_seg:
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# define __percpu %__percpu_seg:
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#else
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#define __percpu
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# define __percpu
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#endif
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#define PER_CPU_VAR(var) __percpu(var)__percpu_rel
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#ifdef CONFIG_X86_64_SMP
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#define INIT_PER_CPU_VAR(var) init_per_cpu__##var
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# define INIT_PER_CPU_VAR(var) init_per_cpu__##var
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#else
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#define INIT_PER_CPU_VAR(var) var
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# define INIT_PER_CPU_VAR(var) var
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#endif
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#else /* ...!ASSEMBLY */
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#else /* !__ASSEMBLY__: */
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#include <linux/build_bug.h>
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#include <linux/stringify.h>
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@ -37,19 +37,19 @@
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#ifdef CONFIG_CC_HAS_NAMED_AS
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#ifdef __CHECKER__
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#define __seg_gs __attribute__((address_space(__seg_gs)))
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#define __seg_fs __attribute__((address_space(__seg_fs)))
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# define __seg_gs __attribute__((address_space(__seg_gs)))
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# define __seg_fs __attribute__((address_space(__seg_fs)))
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#endif
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#ifdef CONFIG_X86_64
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#define __percpu_seg_override __seg_gs
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# define __percpu_seg_override __seg_gs
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#else
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#define __percpu_seg_override __seg_fs
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# define __percpu_seg_override __seg_fs
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#endif
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#define __percpu_prefix ""
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#else /* CONFIG_CC_HAS_NAMED_AS */
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#else /* !CONFIG_CC_HAS_NAMED_AS: */
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#define __percpu_seg_override
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#define __percpu_prefix "%%"__stringify(__percpu_seg)":"
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@ -80,7 +80,8 @@
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#define PER_CPU_VAR(var) %__percpu_seg:(var)__percpu_rel
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#else /* CONFIG_SMP */
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#else /* !CONFIG_SMP: */
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#define __percpu_seg_override
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#define __percpu_prefix ""
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#define __force_percpu_prefix ""
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@ -96,7 +97,7 @@
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#define __force_percpu_arg(x) __force_percpu_prefix "%" #x
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/*
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* Initialized pointers to per-cpu variables needed for the boot
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* Initialized pointers to per-CPU variables needed for the boot
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* processor need to use these macros to get the proper address
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* offset from __per_cpu_load on SMP.
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*
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@ -106,13 +107,15 @@
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extern typeof(var) init_per_cpu_var(var)
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#ifdef CONFIG_X86_64_SMP
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#define init_per_cpu_var(var) init_per_cpu__##var
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# define init_per_cpu_var(var) init_per_cpu__##var
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#else
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#define init_per_cpu_var(var) var
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# define init_per_cpu_var(var) var
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#endif
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/* For arch-specific code, we can use direct single-insn ops (they
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* don't give an lvalue though). */
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/*
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* For arch-specific code, we can use direct single-insn ops (they
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* don't give an lvalue though).
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*/
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#define __pcpu_type_1 u8
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#define __pcpu_type_2 u16
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@ -158,7 +161,7 @@ do { \
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#define __raw_cpu_read_const(pcp) __raw_cpu_read(, , pcp)
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#else /* CONFIG_USE_X86_SEG_SUPPORT */
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#else /* !CONFIG_USE_X86_SEG_SUPPORT: */
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#define __raw_cpu_read(size, qual, _var) \
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({ \
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@ -183,7 +186,7 @@ do { \
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} while (0)
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/*
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* The generic per-cpu infrastrucutre is not suitable for
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* The generic per-CPU infrastrucutre is not suitable for
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* reading const-qualified variables.
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*/
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#define __raw_cpu_read_const(pcp) ({ BUILD_BUG(); (typeof(pcp))0; })
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@ -219,7 +222,7 @@ do { \
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} while (0)
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/*
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* Generate a percpu add to memory instruction and optimize code
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* Generate a per-CPU add to memory instruction and optimize code
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* if one is added or subtracted.
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*/
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#define percpu_add_op(size, qual, var, val) \
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@ -266,9 +269,9 @@ do { \
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})
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/*
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* this_cpu_xchg() is implemented using cmpxchg without a lock prefix.
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* xchg is expensive due to the implied lock prefix. The processor
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* cannot prefetch cachelines if xchg is used.
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* this_cpu_xchg() is implemented using CMPXCHG without a LOCK prefix.
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* XCHG is expensive due to the implied LOCK prefix. The processor
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* cannot prefetch cachelines if XCHG is used.
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*/
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#define this_percpu_xchg_op(_var, _nval) \
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({ \
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@ -278,8 +281,8 @@ do { \
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})
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/*
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* cmpxchg has no such implied lock semantics as a result it is much
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* more efficient for cpu local operations.
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* CMPXCHG has no such implied lock semantics as a result it is much
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* more efficient for CPU-local operations.
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*/
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#define percpu_cmpxchg_op(size, qual, _var, _oval, _nval) \
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({ \
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@ -314,6 +317,7 @@ do { \
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})
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#if defined(CONFIG_X86_32) && !defined(CONFIG_UML)
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#define percpu_cmpxchg64_op(size, qual, _var, _oval, _nval) \
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({ \
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union { \
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@ -374,7 +378,8 @@ do { \
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#define raw_cpu_try_cmpxchg64(pcp, ovalp, nval) percpu_try_cmpxchg64_op(8, , pcp, ovalp, nval)
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#define this_cpu_try_cmpxchg64(pcp, ovalp, nval) percpu_try_cmpxchg64_op(8, volatile, pcp, ovalp, nval)
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#endif
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#endif /* defined(CONFIG_X86_32) && !defined(CONFIG_UML) */
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#ifdef CONFIG_X86_64
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#define raw_cpu_cmpxchg64(pcp, oval, nval) percpu_cmpxchg_op(8, , pcp, oval, nval);
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@ -443,7 +448,8 @@ do { \
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#define raw_cpu_try_cmpxchg128(pcp, ovalp, nval) percpu_try_cmpxchg128_op(16, , pcp, ovalp, nval)
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#define this_cpu_try_cmpxchg128(pcp, ovalp, nval) percpu_try_cmpxchg128_op(16, volatile, pcp, ovalp, nval)
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#endif
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#endif /* CONFIG_X86_64 */
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#define raw_cpu_read_1(pcp) __raw_cpu_read(1, , pcp)
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#define raw_cpu_read_2(pcp) __raw_cpu_read(2, , pcp)
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@ -510,8 +516,8 @@ do { \
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#define this_cpu_try_cmpxchg_4(pcp, ovalp, nval) percpu_try_cmpxchg_op(4, volatile, pcp, ovalp, nval)
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/*
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* Per cpu atomic 64 bit operations are only available under 64 bit.
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* 32 bit must fall back to generic operations.
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* Per-CPU atomic 64-bit operations are only available under 64-bit kernels.
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* 32-bit kernels must fall back to generic operations.
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*/
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#ifdef CONFIG_X86_64
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#define raw_cpu_read_8(pcp) __raw_cpu_read(8, , pcp)
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@ -539,20 +545,23 @@ do { \
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#define this_cpu_try_cmpxchg_8(pcp, ovalp, nval) percpu_try_cmpxchg_op(8, volatile, pcp, ovalp, nval)
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#define raw_cpu_read_long(pcp) raw_cpu_read_8(pcp)
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#else
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/* There is no generic 64 bit read stable operation for 32 bit targets. */
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#else /* !CONFIG_X86_64: */
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/* There is no generic 64-bit read stable operation for 32-bit targets. */
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#define this_cpu_read_stable_8(pcp) ({ BUILD_BUG(); (typeof(pcp))0; })
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#define raw_cpu_read_long(pcp) raw_cpu_read_4(pcp)
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#endif
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#endif /* CONFIG_X86_64 */
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#define this_cpu_read_const(pcp) __raw_cpu_read_const(pcp)
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/*
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* this_cpu_read() makes gcc load the percpu variable every time it is
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* accessed while this_cpu_read_stable() allows the value to be cached.
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* this_cpu_read() makes the compiler load the per-CPU variable every time
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* it is accessed while this_cpu_read_stable() allows the value to be cached.
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* this_cpu_read_stable() is more efficient and can be used if its value
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* is guaranteed to be valid across cpus. The current users include
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* is guaranteed to be valid across CPUs. The current users include
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* pcpu_hot.current_task and pcpu_hot.top_of_stack, both of which are
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* actually per-thread variables implemented as per-CPU variables and
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* thus stable for the duration of the respective task.
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@ -626,12 +635,12 @@ DECLARE_PER_CPU_READ_MOSTLY(unsigned long, this_cpu_off);
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#define early_per_cpu_ptr(_name) (_name##_early_ptr)
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#define early_per_cpu_map(_name, _idx) (_name##_early_map[_idx])
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#define early_per_cpu(_name, _cpu) \
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#define early_per_cpu(_name, _cpu) \
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*(early_per_cpu_ptr(_name) ? \
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&early_per_cpu_ptr(_name)[_cpu] : \
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&per_cpu(_name, _cpu))
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#else /* !CONFIG_SMP */
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#else /* !CONFIG_SMP: */
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#define DEFINE_EARLY_PER_CPU(_type, _name, _initvalue) \
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DEFINE_PER_CPU(_type, _name) = _initvalue
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@ -651,6 +660,6 @@ DECLARE_PER_CPU_READ_MOSTLY(unsigned long, this_cpu_off);
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#define early_per_cpu_ptr(_name) NULL
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/* no early_per_cpu_map() */
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#endif /* !CONFIG_SMP */
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#endif /* CONFIG_SMP */
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#endif /* _ASM_X86_PERCPU_H */
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