From e0fdb0e050eae331046385643618f12452aa7e73 Mon Sep 17 00:00:00 2001 From: Rusty Russell Date: Thu, 29 Oct 2009 22:34:15 +0900 Subject: [PATCH] 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: Rusty Russell Cc: Al Viro Signed-off-by: Tejun Heo --- include/asm-generic/percpu.h | 4 +++- include/linux/compiler.h | 4 +++- include/linux/percpu-defs.h | 2 +- include/linux/percpu.h | 18 +++++++++++------- 4 files changed, 18 insertions(+), 10 deletions(-) diff --git a/include/asm-generic/percpu.h b/include/asm-generic/percpu.h index ca6f0491412..fded453fd25 100644 --- a/include/asm-generic/percpu.h +++ b/include/asm-generic/percpu.h @@ -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 /* diff --git a/include/linux/compiler.h b/include/linux/compiler.h index 04fb5135b4e..abba8045c6e 100644 --- a/include/linux/compiler.h +++ b/include/linux/compiler.h @@ -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__ diff --git a/include/linux/percpu-defs.h b/include/linux/percpu-defs.h index ee99f6c2cdc..0fa0cb52425 100644 --- a/include/linux/percpu-defs.h +++ b/include/linux/percpu-defs.h @@ -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 \ diff --git a/include/linux/percpu.h b/include/linux/percpu.h index f965f833a64..2c0d31a3f6b 100644 --- a/include/linux/percpu.h +++ b/include/linux/percpu.h @@ -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. -- 2.39.5