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Diffstat (limited to 'arch/x86/include/asm/percpu.h')
-rw-r--r--arch/x86/include/asm/percpu.h169
1 files changed, 78 insertions, 91 deletions
diff --git a/arch/x86/include/asm/percpu.h b/arch/x86/include/asm/percpu.h
index ece72053ba6..aee103b26d0 100644
--- a/arch/x86/include/asm/percpu.h
+++ b/arch/x86/include/asm/percpu.h
@@ -2,53 +2,12 @@
#define _ASM_X86_PERCPU_H
#ifdef CONFIG_X86_64
-#include <linux/compiler.h>
-
-/* Same as asm-generic/percpu.h, except that we store the per cpu offset
- in the PDA. Longer term the PDA and every per cpu variable
- should be just put into a single section and referenced directly
- from %gs */
-
-#ifdef CONFIG_SMP
-#include <asm/pda.h>
-
-#define __per_cpu_offset(cpu) (cpu_pda(cpu)->data_offset)
-#define __my_cpu_offset read_pda(data_offset)
-
-#define per_cpu_offset(x) (__per_cpu_offset(x))
-
+#define __percpu_seg gs
+#define __percpu_mov_op movq
+#else
+#define __percpu_seg fs
+#define __percpu_mov_op movl
#endif
-#include <asm-generic/percpu.h>
-
-DECLARE_PER_CPU(struct x8664_pda, pda);
-
-/*
- * These are supposed to be implemented as a single instruction which
- * operates on the per-cpu data base segment. x86-64 doesn't have
- * that yet, so this is a fairly inefficient workaround for the
- * meantime. The single instruction is atomic with respect to
- * preemption and interrupts, so we need to explicitly disable
- * interrupts here to achieve the same effect. However, because it
- * can be used from within interrupt-disable/enable, we can't actually
- * disable interrupts; disabling preemption is enough.
- */
-#define x86_read_percpu(var) \
- ({ \
- typeof(per_cpu_var(var)) __tmp; \
- preempt_disable(); \
- __tmp = __get_cpu_var(var); \
- preempt_enable(); \
- __tmp; \
- })
-
-#define x86_write_percpu(var, val) \
- do { \
- preempt_disable(); \
- __get_cpu_var(var) = (val); \
- preempt_enable(); \
- } while(0)
-
-#else /* CONFIG_X86_64 */
#ifdef __ASSEMBLY__
@@ -65,47 +24,48 @@ DECLARE_PER_CPU(struct x8664_pda, pda);
* PER_CPU(cpu_gdt_descr, %ebx)
*/
#ifdef CONFIG_SMP
-#define PER_CPU(var, reg) \
- movl %fs:per_cpu__##this_cpu_off, reg; \
+#define PER_CPU(var, reg) \
+ __percpu_mov_op %__percpu_seg:per_cpu__this_cpu_off, reg; \
lea per_cpu__##var(reg), reg
-#define PER_CPU_VAR(var) %fs:per_cpu__##var
+#define PER_CPU_VAR(var) %__percpu_seg:per_cpu__##var
#else /* ! SMP */
-#define PER_CPU(var, reg) \
- movl $per_cpu__##var, reg
+#define PER_CPU(var, reg) \
+ __percpu_mov_op $per_cpu__##var, reg
#define PER_CPU_VAR(var) per_cpu__##var
#endif /* SMP */
+#ifdef CONFIG_X86_64_SMP
+#define INIT_PER_CPU_VAR(var) init_per_cpu__##var
+#else
+#define INIT_PER_CPU_VAR(var) per_cpu__##var
+#endif
+
#else /* ...!ASSEMBLY */
+#include <linux/stringify.h>
+
+#ifdef CONFIG_SMP
+#define __percpu_arg(x) "%%"__stringify(__percpu_seg)":%P" #x
+#define __my_cpu_offset percpu_read(this_cpu_off)
+#else
+#define __percpu_arg(x) "%" #x
+#endif
+
/*
- * PER_CPU finds an address of a per-cpu variable.
+ * Initialized pointers to per-cpu variables needed for the boot
+ * processor need to use these macros to get the proper address
+ * offset from __per_cpu_load on SMP.
*
- * Args:
- * var - variable name
- * cpu - 32bit register containing the current CPU number
- *
- * The resulting address is stored in the "cpu" argument.
- *
- * Example:
- * PER_CPU(cpu_gdt_descr, %ebx)
+ * There also must be an entry in vmlinux_64.lds.S
*/
-#ifdef CONFIG_SMP
-
-#define __my_cpu_offset x86_read_percpu(this_cpu_off)
-
-/* fs segment starts at (positive) offset == __per_cpu_offset[cpu] */
-#define __percpu_seg "%%fs:"
-
-#else /* !SMP */
-
-#define __percpu_seg ""
-
-#endif /* SMP */
-
-#include <asm-generic/percpu.h>
+#define DECLARE_INIT_PER_CPU(var) \
+ extern typeof(per_cpu_var(var)) init_per_cpu_var(var)
-/* We can use this directly for local CPU (faster). */
-DECLARE_PER_CPU(unsigned long, this_cpu_off);
+#ifdef CONFIG_X86_64_SMP
+#define init_per_cpu_var(var) init_per_cpu__##var
+#else
+#define init_per_cpu_var(var) per_cpu_var(var)
+#endif
/* For arch-specific code, we can use direct single-insn ops (they
* don't give an lvalue though). */
@@ -120,20 +80,25 @@ do { \
} \
switch (sizeof(var)) { \
case 1: \
- asm(op "b %1,"__percpu_seg"%0" \
+ asm(op "b %1,"__percpu_arg(0) \
: "+m" (var) \
: "ri" ((T__)val)); \
break; \
case 2: \
- asm(op "w %1,"__percpu_seg"%0" \
+ asm(op "w %1,"__percpu_arg(0) \
: "+m" (var) \
: "ri" ((T__)val)); \
break; \
case 4: \
- asm(op "l %1,"__percpu_seg"%0" \
+ asm(op "l %1,"__percpu_arg(0) \
: "+m" (var) \
: "ri" ((T__)val)); \
break; \
+ case 8: \
+ asm(op "q %1,"__percpu_arg(0) \
+ : "+m" (var) \
+ : "re" ((T__)val)); \
+ break; \
default: __bad_percpu_size(); \
} \
} while (0)
@@ -143,17 +108,22 @@ do { \
typeof(var) ret__; \
switch (sizeof(var)) { \
case 1: \
- asm(op "b "__percpu_seg"%1,%0" \
+ asm(op "b "__percpu_arg(1)",%0" \
: "=r" (ret__) \
: "m" (var)); \
break; \
case 2: \
- asm(op "w "__percpu_seg"%1,%0" \
+ asm(op "w "__percpu_arg(1)",%0" \
: "=r" (ret__) \
: "m" (var)); \
break; \
case 4: \
- asm(op "l "__percpu_seg"%1,%0" \
+ asm(op "l "__percpu_arg(1)",%0" \
+ : "=r" (ret__) \
+ : "m" (var)); \
+ break; \
+ case 8: \
+ asm(op "q "__percpu_arg(1)",%0" \
: "=r" (ret__) \
: "m" (var)); \
break; \
@@ -162,13 +132,30 @@ do { \
ret__; \
})
-#define x86_read_percpu(var) percpu_from_op("mov", per_cpu__##var)
-#define x86_write_percpu(var, val) percpu_to_op("mov", per_cpu__##var, val)
-#define x86_add_percpu(var, val) percpu_to_op("add", per_cpu__##var, val)
-#define x86_sub_percpu(var, val) percpu_to_op("sub", per_cpu__##var, val)
-#define x86_or_percpu(var, val) percpu_to_op("or", per_cpu__##var, val)
+#define percpu_read(var) percpu_from_op("mov", per_cpu__##var)
+#define percpu_write(var, val) percpu_to_op("mov", per_cpu__##var, val)
+#define percpu_add(var, val) percpu_to_op("add", per_cpu__##var, val)
+#define percpu_sub(var, val) percpu_to_op("sub", per_cpu__##var, val)
+#define percpu_and(var, val) percpu_to_op("and", per_cpu__##var, val)
+#define percpu_or(var, val) percpu_to_op("or", per_cpu__##var, val)
+#define percpu_xor(var, val) percpu_to_op("xor", per_cpu__##var, val)
+
+/* This is not atomic against other CPUs -- CPU preemption needs to be off */
+#define x86_test_and_clear_bit_percpu(bit, var) \
+({ \
+ int old__; \
+ asm volatile("btr %2,"__percpu_arg(1)"\n\tsbbl %0,%0" \
+ : "=r" (old__), "+m" (per_cpu__##var) \
+ : "dIr" (bit)); \
+ old__; \
+})
+
+#include <asm-generic/percpu.h>
+
+/* We can use this directly for local CPU (faster). */
+DECLARE_PER_CPU(unsigned long, this_cpu_off);
+
#endif /* !__ASSEMBLY__ */
-#endif /* !CONFIG_X86_64 */
#ifdef CONFIG_SMP
@@ -195,9 +182,9 @@ do { \
#define early_per_cpu_ptr(_name) (_name##_early_ptr)
#define early_per_cpu_map(_name, _idx) (_name##_early_map[_idx])
#define early_per_cpu(_name, _cpu) \
- (early_per_cpu_ptr(_name) ? \
- early_per_cpu_ptr(_name)[_cpu] : \
- per_cpu(_name, _cpu))
+ *(early_per_cpu_ptr(_name) ? \
+ &early_per_cpu_ptr(_name)[_cpu] : \
+ &per_cpu(_name, _cpu))
#else /* !CONFIG_SMP */
#define DEFINE_EARLY_PER_CPU(_type, _name, _initvalue) \
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-12-21 03:21:00 +0000