Commit e0fdb0e0 authored by Rusty Russell's avatar Rusty Russell Committed by Tejun Heo
Browse files

percpu: add __percpu for sparse. 



We have to make __kernel "__attribute__((address_space(0)))" so we can
cast to it.

tj: * put_cpu_var() update.

    * Annotations added to dynamic allocator interface.

Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: default avatarTejun Heo <tj@kernel.org>
parent f7b64fe8

include/asm-generic/percpu.h

+3 −1
Original line number Diff line number Diff line
@@ -41,7 +41,9 @@ extern unsigned long __per_cpu_offset[NR_CPUS]; 
 * Only S390 provides its own means of moving the pointer.

 */

#ifndef SHIFT_PERCPU_PTR

#define SHIFT_PERCPU_PTR(__p, __offset)	RELOC_HIDE((__p), (__offset))

/* Weird cast keeps both GCC and sparse happy. */

#define SHIFT_PERCPU_PTR(__p, __offset)				\

	RELOC_HIDE((typeof(*(__p)) __kernel __force *)(__p), (__offset))

#endif



/*

include/linux/compiler.h

+3 −1
Original line number Diff line number Diff line
@@ -5,7 +5,7 @@ 


#ifdef __CHECKER__

# define __user		__attribute__((noderef, address_space(1)))

# define __kernel	/* default address space */

# define __kernel	__attribute__((address_space(0)))

# define __safe		__attribute__((safe))

# define __force	__attribute__((force))

# define __nocast	__attribute__((nocast))
@@ -15,6 +15,7 @@ 
# define __acquire(x)	__context__(x,1)

# define __release(x)	__context__(x,-1)

# define __cond_lock(x,c)	((c) ? ({ __acquire(x); 1; }) : 0)

# define __percpu	__attribute__((noderef, address_space(3)))

extern void __chk_user_ptr(const volatile void __user *);

extern void __chk_io_ptr(const volatile void __iomem *);

#else
@@ -32,6 +33,7 @@ extern void __chk_io_ptr(const volatile void __iomem *); 
# define __acquire(x) (void)0

# define __release(x) (void)0

# define __cond_lock(x,c) (c)

# define __percpu

#endif



#ifdef __KERNEL__

include/linux/percpu-defs.h

+1 −1
Original line number Diff line number Diff line
@@ -12,7 +12,7 @@ 
 * that section.

 */

#define __PCPU_ATTRS(sec)						\

	__attribute__((section(PER_CPU_BASE_SECTION sec)))		\

	__percpu __attribute__((section(PER_CPU_BASE_SECTION sec)))	\

	PER_CPU_ATTRIBUTES



#define __PCPU_DUMMY_ATTRS						\

include/linux/percpu.h

+11 −7
Original line number Diff line number Diff line
@@ -30,8 +30,12 @@ 
	preempt_disable();				\

	&__get_cpu_var(var); }))



/*

 * 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);					\

	(void)&(var);					\

	preempt_enable();				\

} while (0)
@@ -130,9 +134,9 @@ extern int __init pcpu_page_first_chunk(size_t reserved_size, 
 */

#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);

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);
@@ -142,7 +146,7 @@ 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
@@ -153,7 +157,7 @@ static inline void *__alloc_percpu(size_t size, size_t align) 
	return kzalloc(size, GFP_KERNEL);

}



static inline void free_percpu(void *p)

static inline void free_percpu(void __percpu *p)

{

	kfree(p);

}
@@ -168,7 +172,7 @@ static inline void *pcpu_lpage_remapped(void *kaddr) 
#endif /* CONFIG_SMP */



#define alloc_percpu(type)	\

	(typeof(type) *)__alloc_percpu(sizeof(type), __alignof__(type))

	(typeof(type) __percpu *)__alloc_percpu(sizeof(type), __alignof__(type))



/*

 * Optional methods for optimized non-lvalue per-cpu variable access.

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