* we force a syntax error here if it isn't.
*/
#define get_cpu_var(var) (*({ \
- extern int simple_identifier_##var(void); \
preempt_disable(); \
&__get_cpu_var(var); }))
-#define put_cpu_var(var) preempt_enable()
-#ifdef CONFIG_SMP
+/*
+ * The weird & is necessary because sparse considers (void)(var) to be
+ * a direct dereference of percpu variable (var).
+ */
+#define put_cpu_var(var) do { \
+ (void)&(var); \
+ preempt_enable(); \
+} while (0)
-#ifndef CONFIG_HAVE_LEGACY_PER_CPU_AREA
+#ifdef CONFIG_SMP
/* minimum unit size, also is the maximum supported allocation size */
#define PCPU_MIN_UNIT_SIZE PFN_ALIGN(64 << 10)
*/
#define per_cpu_ptr(ptr, cpu) SHIFT_PERCPU_PTR((ptr), per_cpu_offset((cpu)))
-extern void *__alloc_reserved_percpu(size_t size, size_t align);
-
-#else /* CONFIG_HAVE_LEGACY_PER_CPU_AREA */
-
-struct percpu_data {
- void *ptrs[1];
-};
-
-/* pointer disguising messes up the kmemleak objects tracking */
-#ifndef CONFIG_DEBUG_KMEMLEAK
-#define __percpu_disguise(pdata) (struct percpu_data *)~(unsigned long)(pdata)
-#else
-#define __percpu_disguise(pdata) (struct percpu_data *)(pdata)
-#endif
-
-#define per_cpu_ptr(ptr, cpu) \
-({ \
- struct percpu_data *__p = __percpu_disguise(ptr); \
- (__typeof__(ptr))__p->ptrs[(cpu)]; \
-})
-
-#endif /* CONFIG_HAVE_LEGACY_PER_CPU_AREA */
-
-extern void *__alloc_percpu(size_t size, size_t align);
-extern void free_percpu(void *__pdata);
+extern void __percpu *__alloc_reserved_percpu(size_t size, size_t align);
+extern void __percpu *__alloc_percpu(size_t size, size_t align);
+extern void free_percpu(void __percpu *__pdata);
#ifndef CONFIG_HAVE_SETUP_PER_CPU_AREA
extern void __init setup_per_cpu_areas(void);
#define per_cpu_ptr(ptr, cpu) ({ (void)(cpu); (ptr); })
-static inline void *__alloc_percpu(size_t size, size_t align)
+static inline void __percpu *__alloc_percpu(size_t size, size_t align)
{
/*
* Can't easily make larger alignment work with kmalloc. WARN
return kzalloc(size, GFP_KERNEL);
}
-static inline void free_percpu(void *p)
+static inline void free_percpu(void __percpu *p)
{
kfree(p);
}
#endif /* CONFIG_SMP */
-#define alloc_percpu(type) (type *)__alloc_percpu(sizeof(type), \
- __alignof__(type))
+#define alloc_percpu(type) \
+ (typeof(type) __percpu *)__alloc_percpu(sizeof(type), __alignof__(type))
/*
* Optional methods for optimized non-lvalue per-cpu variable access.
#ifndef percpu_read
# define percpu_read(var) \
({ \
- typeof(per_cpu_var(var)) __tmp_var__; \
- __tmp_var__ = get_cpu_var(var); \
- put_cpu_var(var); \
- __tmp_var__; \
+ typeof(var) *pr_ptr__ = &(var); \
+ typeof(var) pr_ret__; \
+ pr_ret__ = get_cpu_var(*pr_ptr__); \
+ put_cpu_var(*pr_ptr__); \
+ pr_ret__; \
})
#endif
#define __percpu_generic_to_op(var, val, op) \
do { \
- get_cpu_var(var) op val; \
- put_cpu_var(var); \
+ typeof(var) *pgto_ptr__ = &(var); \
+ get_cpu_var(*pgto_ptr__) op val; \
+ put_cpu_var(*pgto_ptr__); \
} while (0)
#ifndef percpu_write
# define percpu_xor(var, val) __percpu_generic_to_op(var, (val), ^=)
#endif
+/*
+ * Branching function to split up a function into a set of functions that
+ * are called for different scalar sizes of the objects handled.
+ */
+
+extern void __bad_size_call_parameter(void);
+
+#define __pcpu_size_call_return(stem, variable) \
+({ typeof(variable) pscr_ret__; \
+ __verify_pcpu_ptr(&(variable)); \
+ switch(sizeof(variable)) { \
+ case 1: pscr_ret__ = stem##1(variable);break; \
+ case 2: pscr_ret__ = stem##2(variable);break; \
+ case 4: pscr_ret__ = stem##4(variable);break; \
+ case 8: pscr_ret__ = stem##8(variable);break; \
+ default: \
+ __bad_size_call_parameter();break; \
+ } \
+ pscr_ret__; \
+})
+
+#define __pcpu_size_call(stem, variable, ...) \
+do { \
+ __verify_pcpu_ptr(&(variable)); \
+ switch(sizeof(variable)) { \
+ case 1: stem##1(variable, __VA_ARGS__);break; \
+ case 2: stem##2(variable, __VA_ARGS__);break; \
+ case 4: stem##4(variable, __VA_ARGS__);break; \
+ case 8: stem##8(variable, __VA_ARGS__);break; \
+ default: \
+ __bad_size_call_parameter();break; \
+ } \
+} while (0)
+
+/*
+ * Optimized manipulation for memory allocated through the per cpu
+ * allocator or for addresses of per cpu variables.
+ *
+ * These operation guarantee exclusivity of access for other operations
+ * on the *same* processor. The assumption is that per cpu data is only
+ * accessed by a single processor instance (the current one).
+ *
+ * The first group is used for accesses that must be done in a
+ * preemption safe way since we know that the context is not preempt
+ * safe. Interrupts may occur. If the interrupt modifies the variable
+ * too then RMW actions will not be reliable.
+ *
+ * The arch code can provide optimized functions in two ways:
+ *
+ * 1. Override the function completely. F.e. define this_cpu_add().
+ * The arch must then ensure that the various scalar format passed
+ * are handled correctly.
+ *
+ * 2. Provide functions for certain scalar sizes. F.e. provide
+ * this_cpu_add_2() to provide per cpu atomic operations for 2 byte
+ * sized RMW actions. If arch code does not provide operations for
+ * a scalar size then the fallback in the generic code will be
+ * used.
+ */
+
+#define _this_cpu_generic_read(pcp) \
+({ typeof(pcp) ret__; \
+ preempt_disable(); \
+ ret__ = *this_cpu_ptr(&(pcp)); \
+ preempt_enable(); \
+ ret__; \
+})
+
+#ifndef this_cpu_read
+# ifndef this_cpu_read_1
+# define this_cpu_read_1(pcp) _this_cpu_generic_read(pcp)
+# endif
+# ifndef this_cpu_read_2
+# define this_cpu_read_2(pcp) _this_cpu_generic_read(pcp)
+# endif
+# ifndef this_cpu_read_4
+# define this_cpu_read_4(pcp) _this_cpu_generic_read(pcp)
+# endif
+# ifndef this_cpu_read_8
+# define this_cpu_read_8(pcp) _this_cpu_generic_read(pcp)
+# endif
+# define this_cpu_read(pcp) __pcpu_size_call_return(this_cpu_read_, (pcp))
+#endif
+
+#define _this_cpu_generic_to_op(pcp, val, op) \
+do { \
+ preempt_disable(); \
+ *__this_cpu_ptr(&(pcp)) op val; \
+ preempt_enable(); \
+} while (0)
+
+#ifndef this_cpu_write
+# ifndef this_cpu_write_1
+# define this_cpu_write_1(pcp, val) _this_cpu_generic_to_op((pcp), (val), =)
+# endif
+# ifndef this_cpu_write_2
+# define this_cpu_write_2(pcp, val) _this_cpu_generic_to_op((pcp), (val), =)
+# endif
+# ifndef this_cpu_write_4
+# define this_cpu_write_4(pcp, val) _this_cpu_generic_to_op((pcp), (val), =)
+# endif
+# ifndef this_cpu_write_8
+# define this_cpu_write_8(pcp, val) _this_cpu_generic_to_op((pcp), (val), =)
+# endif
+# define this_cpu_write(pcp, val) __pcpu_size_call(this_cpu_write_, (pcp), (val))
+#endif
+
+#ifndef this_cpu_add
+# ifndef this_cpu_add_1
+# define this_cpu_add_1(pcp, val) _this_cpu_generic_to_op((pcp), (val), +=)
+# endif
+# ifndef this_cpu_add_2
+# define this_cpu_add_2(pcp, val) _this_cpu_generic_to_op((pcp), (val), +=)
+# endif
+# ifndef this_cpu_add_4
+# define this_cpu_add_4(pcp, val) _this_cpu_generic_to_op((pcp), (val), +=)
+# endif
+# ifndef this_cpu_add_8
+# define this_cpu_add_8(pcp, val) _this_cpu_generic_to_op((pcp), (val), +=)
+# endif
+# define this_cpu_add(pcp, val) __pcpu_size_call(this_cpu_add_, (pcp), (val))
+#endif
+
+#ifndef this_cpu_sub
+# define this_cpu_sub(pcp, val) this_cpu_add((pcp), -(val))
+#endif
+
+#ifndef this_cpu_inc
+# define this_cpu_inc(pcp) this_cpu_add((pcp), 1)
+#endif
+
+#ifndef this_cpu_dec
+# define this_cpu_dec(pcp) this_cpu_sub((pcp), 1)
+#endif
+
+#ifndef this_cpu_and
+# ifndef this_cpu_and_1
+# define this_cpu_and_1(pcp, val) _this_cpu_generic_to_op((pcp), (val), &=)
+# endif
+# ifndef this_cpu_and_2
+# define this_cpu_and_2(pcp, val) _this_cpu_generic_to_op((pcp), (val), &=)
+# endif
+# ifndef this_cpu_and_4
+# define this_cpu_and_4(pcp, val) _this_cpu_generic_to_op((pcp), (val), &=)
+# endif
+# ifndef this_cpu_and_8
+# define this_cpu_and_8(pcp, val) _this_cpu_generic_to_op((pcp), (val), &=)
+# endif
+# define this_cpu_and(pcp, val) __pcpu_size_call(this_cpu_and_, (pcp), (val))
+#endif
+
+#ifndef this_cpu_or
+# ifndef this_cpu_or_1
+# define this_cpu_or_1(pcp, val) _this_cpu_generic_to_op((pcp), (val), |=)
+# endif
+# ifndef this_cpu_or_2
+# define this_cpu_or_2(pcp, val) _this_cpu_generic_to_op((pcp), (val), |=)
+# endif
+# ifndef this_cpu_or_4
+# define this_cpu_or_4(pcp, val) _this_cpu_generic_to_op((pcp), (val), |=)
+# endif
+# ifndef this_cpu_or_8
+# define this_cpu_or_8(pcp, val) _this_cpu_generic_to_op((pcp), (val), |=)
+# endif
+# define this_cpu_or(pcp, val) __pcpu_size_call(this_cpu_or_, (pcp), (val))
+#endif
+
+#ifndef this_cpu_xor
+# ifndef this_cpu_xor_1
+# define this_cpu_xor_1(pcp, val) _this_cpu_generic_to_op((pcp), (val), ^=)
+# endif
+# ifndef this_cpu_xor_2
+# define this_cpu_xor_2(pcp, val) _this_cpu_generic_to_op((pcp), (val), ^=)
+# endif
+# ifndef this_cpu_xor_4
+# define this_cpu_xor_4(pcp, val) _this_cpu_generic_to_op((pcp), (val), ^=)
+# endif
+# ifndef this_cpu_xor_8
+# define this_cpu_xor_8(pcp, val) _this_cpu_generic_to_op((pcp), (val), ^=)
+# endif
+# define this_cpu_xor(pcp, val) __pcpu_size_call(this_cpu_or_, (pcp), (val))
+#endif
+
+/*
+ * Generic percpu operations that do not require preemption handling.
+ * Either we do not care about races or the caller has the
+ * responsibility of handling preemptions issues. Arch code can still
+ * override these instructions since the arch per cpu code may be more
+ * efficient and may actually get race freeness for free (that is the
+ * case for x86 for example).
+ *
+ * If there is no other protection through preempt disable and/or
+ * disabling interupts then one of these RMW operations can show unexpected
+ * behavior because the execution thread was rescheduled on another processor
+ * or an interrupt occurred and the same percpu variable was modified from
+ * the interrupt context.
+ */
+#ifndef __this_cpu_read
+# ifndef __this_cpu_read_1
+# define __this_cpu_read_1(pcp) (*__this_cpu_ptr(&(pcp)))
+# endif
+# ifndef __this_cpu_read_2
+# define __this_cpu_read_2(pcp) (*__this_cpu_ptr(&(pcp)))
+# endif
+# ifndef __this_cpu_read_4
+# define __this_cpu_read_4(pcp) (*__this_cpu_ptr(&(pcp)))
+# endif
+# ifndef __this_cpu_read_8
+# define __this_cpu_read_8(pcp) (*__this_cpu_ptr(&(pcp)))
+# endif
+# define __this_cpu_read(pcp) __pcpu_size_call_return(__this_cpu_read_, (pcp))
+#endif
+
+#define __this_cpu_generic_to_op(pcp, val, op) \
+do { \
+ *__this_cpu_ptr(&(pcp)) op val; \
+} while (0)
+
+#ifndef __this_cpu_write
+# ifndef __this_cpu_write_1
+# define __this_cpu_write_1(pcp, val) __this_cpu_generic_to_op((pcp), (val), =)
+# endif
+# ifndef __this_cpu_write_2
+# define __this_cpu_write_2(pcp, val) __this_cpu_generic_to_op((pcp), (val), =)
+# endif
+# ifndef __this_cpu_write_4
+# define __this_cpu_write_4(pcp, val) __this_cpu_generic_to_op((pcp), (val), =)
+# endif
+# ifndef __this_cpu_write_8
+# define __this_cpu_write_8(pcp, val) __this_cpu_generic_to_op((pcp), (val), =)
+# endif
+# define __this_cpu_write(pcp, val) __pcpu_size_call(__this_cpu_write_, (pcp), (val))
+#endif
+
+#ifndef __this_cpu_add
+# ifndef __this_cpu_add_1
+# define __this_cpu_add_1(pcp, val) __this_cpu_generic_to_op((pcp), (val), +=)
+# endif
+# ifndef __this_cpu_add_2
+# define __this_cpu_add_2(pcp, val) __this_cpu_generic_to_op((pcp), (val), +=)
+# endif
+# ifndef __this_cpu_add_4
+# define __this_cpu_add_4(pcp, val) __this_cpu_generic_to_op((pcp), (val), +=)
+# endif
+# ifndef __this_cpu_add_8
+# define __this_cpu_add_8(pcp, val) __this_cpu_generic_to_op((pcp), (val), +=)
+# endif
+# define __this_cpu_add(pcp, val) __pcpu_size_call(__this_cpu_add_, (pcp), (val))
+#endif
+
+#ifndef __this_cpu_sub
+# define __this_cpu_sub(pcp, val) __this_cpu_add((pcp), -(val))
+#endif
+
+#ifndef __this_cpu_inc
+# define __this_cpu_inc(pcp) __this_cpu_add((pcp), 1)
+#endif
+
+#ifndef __this_cpu_dec
+# define __this_cpu_dec(pcp) __this_cpu_sub((pcp), 1)
+#endif
+
+#ifndef __this_cpu_and
+# ifndef __this_cpu_and_1
+# define __this_cpu_and_1(pcp, val) __this_cpu_generic_to_op((pcp), (val), &=)
+# endif
+# ifndef __this_cpu_and_2
+# define __this_cpu_and_2(pcp, val) __this_cpu_generic_to_op((pcp), (val), &=)
+# endif
+# ifndef __this_cpu_and_4
+# define __this_cpu_and_4(pcp, val) __this_cpu_generic_to_op((pcp), (val), &=)
+# endif
+# ifndef __this_cpu_and_8
+# define __this_cpu_and_8(pcp, val) __this_cpu_generic_to_op((pcp), (val), &=)
+# endif
+# define __this_cpu_and(pcp, val) __pcpu_size_call(__this_cpu_and_, (pcp), (val))
+#endif
+
+#ifndef __this_cpu_or
+# ifndef __this_cpu_or_1
+# define __this_cpu_or_1(pcp, val) __this_cpu_generic_to_op((pcp), (val), |=)
+# endif
+# ifndef __this_cpu_or_2
+# define __this_cpu_or_2(pcp, val) __this_cpu_generic_to_op((pcp), (val), |=)
+# endif
+# ifndef __this_cpu_or_4
+# define __this_cpu_or_4(pcp, val) __this_cpu_generic_to_op((pcp), (val), |=)
+# endif
+# ifndef __this_cpu_or_8
+# define __this_cpu_or_8(pcp, val) __this_cpu_generic_to_op((pcp), (val), |=)
+# endif
+# define __this_cpu_or(pcp, val) __pcpu_size_call(__this_cpu_or_, (pcp), (val))
+#endif
+
+#ifndef __this_cpu_xor
+# ifndef __this_cpu_xor_1
+# define __this_cpu_xor_1(pcp, val) __this_cpu_generic_to_op((pcp), (val), ^=)
+# endif
+# ifndef __this_cpu_xor_2
+# define __this_cpu_xor_2(pcp, val) __this_cpu_generic_to_op((pcp), (val), ^=)
+# endif
+# ifndef __this_cpu_xor_4
+# define __this_cpu_xor_4(pcp, val) __this_cpu_generic_to_op((pcp), (val), ^=)
+# endif
+# ifndef __this_cpu_xor_8
+# define __this_cpu_xor_8(pcp, val) __this_cpu_generic_to_op((pcp), (val), ^=)
+# endif
+# define __this_cpu_xor(pcp, val) __pcpu_size_call(__this_cpu_xor_, (pcp), (val))
+#endif
+
+/*
+ * IRQ safe versions of the per cpu RMW operations. Note that these operations
+ * are *not* safe against modification of the same variable from another
+ * processors (which one gets when using regular atomic operations)
+ . They are guaranteed to be atomic vs. local interrupts and
+ * preemption only.
+ */
+#define irqsafe_cpu_generic_to_op(pcp, val, op) \
+do { \
+ unsigned long flags; \
+ local_irq_save(flags); \
+ *__this_cpu_ptr(&(pcp)) op val; \
+ local_irq_restore(flags); \
+} while (0)
+
+#ifndef irqsafe_cpu_add
+# ifndef irqsafe_cpu_add_1
+# define irqsafe_cpu_add_1(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), +=)
+# endif
+# ifndef irqsafe_cpu_add_2
+# define irqsafe_cpu_add_2(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), +=)
+# endif
+# ifndef irqsafe_cpu_add_4
+# define irqsafe_cpu_add_4(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), +=)
+# endif
+# ifndef irqsafe_cpu_add_8
+# define irqsafe_cpu_add_8(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), +=)
+# endif
+# define irqsafe_cpu_add(pcp, val) __pcpu_size_call(irqsafe_cpu_add_, (pcp), (val))
+#endif
+
+#ifndef irqsafe_cpu_sub
+# define irqsafe_cpu_sub(pcp, val) irqsafe_cpu_add((pcp), -(val))
+#endif
+
+#ifndef irqsafe_cpu_inc
+# define irqsafe_cpu_inc(pcp) irqsafe_cpu_add((pcp), 1)
+#endif
+
+#ifndef irqsafe_cpu_dec
+# define irqsafe_cpu_dec(pcp) irqsafe_cpu_sub((pcp), 1)
+#endif
+
+#ifndef irqsafe_cpu_and
+# ifndef irqsafe_cpu_and_1
+# define irqsafe_cpu_and_1(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), &=)
+# endif
+# ifndef irqsafe_cpu_and_2
+# define irqsafe_cpu_and_2(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), &=)
+# endif
+# ifndef irqsafe_cpu_and_4
+# define irqsafe_cpu_and_4(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), &=)
+# endif
+# ifndef irqsafe_cpu_and_8
+# define irqsafe_cpu_and_8(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), &=)
+# endif
+# define irqsafe_cpu_and(pcp, val) __pcpu_size_call(irqsafe_cpu_and_, (val))
+#endif
+
+#ifndef irqsafe_cpu_or
+# ifndef irqsafe_cpu_or_1
+# define irqsafe_cpu_or_1(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), |=)
+# endif
+# ifndef irqsafe_cpu_or_2
+# define irqsafe_cpu_or_2(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), |=)
+# endif
+# ifndef irqsafe_cpu_or_4
+# define irqsafe_cpu_or_4(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), |=)
+# endif
+# ifndef irqsafe_cpu_or_8
+# define irqsafe_cpu_or_8(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), |=)
+# endif
+# define irqsafe_cpu_or(pcp, val) __pcpu_size_call(irqsafe_cpu_or_, (val))
+#endif
+
+#ifndef irqsafe_cpu_xor
+# ifndef irqsafe_cpu_xor_1
+# define irqsafe_cpu_xor_1(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), ^=)
+# endif
+# ifndef irqsafe_cpu_xor_2
+# define irqsafe_cpu_xor_2(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), ^=)
+# endif
+# ifndef irqsafe_cpu_xor_4
+# define irqsafe_cpu_xor_4(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), ^=)
+# endif
+# ifndef irqsafe_cpu_xor_8
+# define irqsafe_cpu_xor_8(pcp, val) irqsafe_cpu_generic_to_op((pcp), (val), ^=)
+# endif
+# define irqsafe_cpu_xor(pcp, val) __pcpu_size_call(irqsafe_cpu_xor_, (val))
+#endif
+
#endif /* __LINUX_PERCPU_H */
git.samba.org / sfrench / cifs-2.6.git / blobdiff