/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _ASM_X86_PERCPU_H #define _ASM_X86_PERCPU_H #ifdef CONFIG_X86_64 #define __percpu_seg gs #else #define __percpu_seg fs #endif #ifdef __ASSEMBLY__ #ifdef CONFIG_SMP #define PER_CPU_VAR(var) %__percpu_seg:var #else /* ! SMP */ #define PER_CPU_VAR(var) 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) var #endif #else /* ...!ASSEMBLY */ #include #include #ifdef CONFIG_SMP #define __percpu_prefix "%%"__stringify(__percpu_seg)":" #define __my_cpu_offset this_cpu_read(this_cpu_off) /* * Compared to the generic __my_cpu_offset version, the following * saves one instruction and avoids clobbering a temp register. */ #define arch_raw_cpu_ptr(ptr) \ ({ \ unsigned long tcp_ptr__; \ asm ("add " __percpu_arg(1) ", %0" \ : "=r" (tcp_ptr__) \ : "m" (this_cpu_off), "0" (ptr)); \ (typeof(*(ptr)) __kernel __force *)tcp_ptr__; \ }) #else #define __percpu_prefix "" #endif #define __percpu_arg(x) __percpu_prefix "%" #x /* * 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. * * There also must be an entry in vmlinux_64.lds.S */ #define DECLARE_INIT_PER_CPU(var) \ extern typeof(var) init_per_cpu_var(var) #ifdef CONFIG_X86_64_SMP #define init_per_cpu_var(var) init_per_cpu__##var #else #define init_per_cpu_var(var) var #endif /* For arch-specific code, we can use direct single-insn ops (they * don't give an lvalue though). */ #define __pcpu_type_1 u8 #define __pcpu_type_2 u16 #define __pcpu_type_4 u32 #define __pcpu_type_8 u64 #define __pcpu_cast_1(val) ((u8)(((unsigned long) val) & 0xff)) #define __pcpu_cast_2(val) ((u16)(((unsigned long) val) & 0xffff)) #define __pcpu_cast_4(val) ((u32)(((unsigned long) val) & 0xffffffff)) #define __pcpu_cast_8(val) ((u64)(val)) #define __pcpu_op1_1(op, dst) op "b " dst #define __pcpu_op1_2(op, dst) op "w " dst #define __pcpu_op1_4(op, dst) op "l " dst #define __pcpu_op1_8(op, dst) op "q " dst #define __pcpu_op2_1(op, src, dst) op "b " src ", " dst #define __pcpu_op2_2(op, src, dst) op "w " src ", " dst #define __pcpu_op2_4(op, src, dst) op "l " src ", " dst #define __pcpu_op2_8(op, src, dst) op "q " src ", " dst #define __pcpu_reg_1(mod, x) mod "q" (x) #define __pcpu_reg_2(mod, x) mod "r" (x) #define __pcpu_reg_4(mod, x) mod "r" (x) #define __pcpu_reg_8(mod, x) mod "r" (x) #define __pcpu_reg_imm_1(x) "qi" (x) #define __pcpu_reg_imm_2(x) "ri" (x) #define __pcpu_reg_imm_4(x) "ri" (x) #define __pcpu_reg_imm_8(x) "re" (x) #define percpu_to_op(size, qual, op, _var, _val) \ do { \ __pcpu_type_##size pto_val__ = __pcpu_cast_##size(_val); \ if (0) { \ typeof(_var) pto_tmp__; \ pto_tmp__ = (_val); \ (void)pto_tmp__; \ } \ asm qual(__pcpu_op2_##size(op, "%[val]", __percpu_arg([var])) \ : [var] "+m" (_var) \ : [val] __pcpu_reg_imm_##size(pto_val__)); \ } while (0) #define percpu_unary_op(size, qual, op, _var) \ ({ \ asm qual (__pcpu_op1_##size(op, __percpu_arg([var])) \ : [var] "+m" (_var)); \ }) /* * Generate a percpu add to memory instruction and optimize code * if one is added or subtracted. */ #define percpu_add_op(size, qual, var, val) \ do { \ const int pao_ID__ = (__builtin_constant_p(val) && \ ((val) == 1 || (val) == -1)) ? \ (int)(val) : 0; \ if (0) { \ typeof(var) pao_tmp__; \ pao_tmp__ = (val); \ (void)pao_tmp__; \ } \ if (pao_ID__ == 1) \ percpu_unary_op(size, qual, "inc", var); \ else if (pao_ID__ == -1) \ percpu_unary_op(size, qual, "dec", var); \ else \ percpu_to_op(size, qual, "add", var, val); \ } while (0) #define percpu_from_op(size, qual, op, _var) \ ({ \ __pcpu_type_##size pfo_val__; \ asm qual (__pcpu_op2_##size(op, __percpu_arg([var]), "%[val]") \ : [val] __pcpu_reg_##size("=", pfo_val__) \ : [var] "m" (_var)); \ (typeof(_var))(unsigned long) pfo_val__; \ }) #define percpu_stable_op(size, op, _var) \ ({ \ __pcpu_type_##size pfo_val__; \ asm(__pcpu_op2_##size(op, __percpu_arg(P[var]), "%[val]") \ : [val] __pcpu_reg_##size("=", pfo_val__) \ : [var] "p" (&(_var))); \ (typeof(_var))(unsigned long) pfo_val__; \ }) /* * Add return operation */ #define percpu_add_return_op(size, qual, _var, _val) \ ({ \ __pcpu_type_##size paro_tmp__ = __pcpu_cast_##size(_val); \ asm qual (__pcpu_op2_##size("xadd", "%[tmp]", \ __percpu_arg([var])) \ : [tmp] __pcpu_reg_##size("+", paro_tmp__), \ [var] "+m" (_var) \ : : "memory"); \ (typeof(_var))(unsigned long) (paro_tmp__ + _val); \ }) /* * xchg is implemented using cmpxchg without a lock prefix. xchg is * expensive due to the implied lock prefix. The processor cannot prefetch * cachelines if xchg is used. */ #define percpu_xchg_op(size, qual, _var, _nval) \ ({ \ __pcpu_type_##size pxo_old__; \ __pcpu_type_##size pxo_new__ = __pcpu_cast_##size(_nval); \ asm qual (__pcpu_op2_##size("mov", __percpu_arg([var]), \ "%[oval]") \ "\n1:\t" \ __pcpu_op2_##size("cmpxchg", "%[nval]", \ __percpu_arg([var])) \ "\n\tjnz 1b" \ : [oval] "=&a" (pxo_old__), \ [var] "+m" (_var) \ : [nval] __pcpu_reg_##size(, pxo_new__) \ : "memory"); \ (typeof(_var))(unsigned long) pxo_old__; \ }) /* * cmpxchg has no such implied lock semantics as a result it is much * more efficient for cpu local operations. */ #define percpu_cmpxchg_op(size, qual, _var, _oval, _nval) \ ({ \ __pcpu_type_##size pco_old__ = __pcpu_cast_##size(_oval); \ __pcpu_type_##size pco_new__ = __pcpu_cast_##size(_nval); \ asm qual (__pcpu_op2_##size("cmpxchg", "%[nval]", \ __percpu_arg([var])) \ : [oval] "+a" (pco_old__), \ [var] "+m" (_var) \ : [nval] __pcpu_reg_##size(, pco_new__) \ : "memory"); \ (typeof(_var))(unsigned long) pco_old__; \ }) /* * this_cpu_read() makes gcc load the percpu variable every time it is * accessed while this_cpu_read_stable() allows the value to be cached. * this_cpu_read_stable() is more efficient and can be used if its value * is guaranteed to be valid across cpus. The current users include * get_current() and get_thread_info() both of which are actually * per-thread variables implemented as per-cpu variables and thus * stable for the duration of the respective task. */ #define this_cpu_read_stable_1(pcp) percpu_stable_op(1, "mov", pcp) #define this_cpu_read_stable_2(pcp) percpu_stable_op(2, "mov", pcp) #define this_cpu_read_stable_4(pcp) percpu_stable_op(4, "mov", pcp) #define this_cpu_read_stable_8(pcp) percpu_stable_op(8, "mov", pcp) #define this_cpu_read_stable(pcp) __pcpu_size_call_return(this_cpu_read_stable_, pcp) #define raw_cpu_read_1(pcp) percpu_from_op(1, , "mov", pcp) #define raw_cpu_read_2(pcp) percpu_from_op(2, , "mov", pcp) #define raw_cpu_read_4(pcp) percpu_from_op(4, , "mov", pcp) #define raw_cpu_write_1(pcp, val) percpu_to_op(1, , "mov", (pcp), val) #define raw_cpu_write_2(pcp, val) percpu_to_op(2, , "mov", (pcp), val) #define raw_cpu_write_4(pcp, val) percpu_to_op(4, , "mov", (pcp), val) #define raw_cpu_add_1(pcp, val) percpu_add_op(1, , (pcp), val) #define raw_cpu_add_2(pcp, val) percpu_add_op(2, , (pcp), val) #define raw_cpu_add_4(pcp, val) percpu_add_op(4, , (pcp), val) #define raw_cpu_and_1(pcp, val) percpu_to_op(1, , "and", (pcp), val) #define raw_cpu_and_2(pcp, val) percpu_to_op(2, , "and", (pcp), val) #define raw_cpu_and_4(pcp, val) percpu_to_op(4, , "and", (pcp), val) #define raw_cpu_or_1(pcp, val) percpu_to_op(1, , "or", (pcp), val) #define raw_cpu_or_2(pcp, val) percpu_to_op(2, , "or", (pcp), val) #define raw_cpu_or_4(pcp, val) percpu_to_op(4, , "or", (pcp), val) /* * raw_cpu_xchg() can use a load-store since it is not required to be * IRQ-safe. */ #define raw_percpu_xchg_op(var, nval) \ ({ \ typeof(var) pxo_ret__ = raw_cpu_read(var); \ raw_cpu_write(var, (nval)); \ pxo_ret__; \ }) #define raw_cpu_xchg_1(pcp, val) raw_percpu_xchg_op(pcp, val) #define raw_cpu_xchg_2(pcp, val) raw_percpu_xchg_op(pcp, val) #define raw_cpu_xchg_4(pcp, val) raw_percpu_xchg_op(pcp, val) #define this_cpu_read_1(pcp) percpu_from_op(1, volatile, "mov", pcp) #define this_cpu_read_2(pcp) percpu_from_op(2, volatile, "mov", pcp) #define this_cpu_read_4(pcp) percpu_from_op(4, volatile, "mov", pcp) #define this_cpu_write_1(pcp, val) percpu_to_op(1, volatile, "mov", (pcp), val) #define this_cpu_write_2(pcp, val) percpu_to_op(2, volatile, "mov", (pcp), val) #define this_cpu_write_4(pcp, val) percpu_to_op(4, volatile, "mov", (pcp), val) #define this_cpu_add_1(pcp, val) percpu_add_op(1, volatile, (pcp), val) #define this_cpu_add_2(pcp, val) percpu_add_op(2, volatile, (pcp), val) #define this_cpu_add_4(pcp, val) percpu_add_op(4, volatile, (pcp), val) #define this_cpu_and_1(pcp, val) percpu_to_op(1, volatile, "and", (pcp), val) #define this_cpu_and_2(pcp, val) percpu_to_op(2, volatile, "and", (pcp), val) #define this_cpu_and_4(pcp, val) percpu_to_op(4, volatile, "and", (pcp), val) #define this_cpu_or_1(pcp, val) percpu_to_op(1, volatile, "or", (pcp), val) #define this_cpu_or_2(pcp, val) percpu_to_op(2, volatile, "or", (pcp), val) #define this_cpu_or_4(pcp, val) percpu_to_op(4, volatile, "or", (pcp), val) #define this_cpu_xchg_1(pcp, nval) percpu_xchg_op(1, volatile, pcp, nval) #define this_cpu_xchg_2(pcp, nval) percpu_xchg_op(2, volatile, pcp, nval) #define this_cpu_xchg_4(pcp, nval) percpu_xchg_op(4, volatile, pcp, nval) #define raw_cpu_add_return_1(pcp, val) percpu_add_return_op(1, , pcp, val) #define raw_cpu_add_return_2(pcp, val) percpu_add_return_op(2, , pcp, val) #define raw_cpu_add_return_4(pcp, val) percpu_add_return_op(4, , pcp, val) #define raw_cpu_cmpxchg_1(pcp, oval, nval) percpu_cmpxchg_op(1, , pcp, oval, nval) #define raw_cpu_cmpxchg_2(pcp, oval, nval) percpu_cmpxchg_op(2, , pcp, oval, nval) #define raw_cpu_cmpxchg_4(pcp, oval, nval) percpu_cmpxchg_op(4, , pcp, oval, nval) #define this_cpu_add_return_1(pcp, val) percpu_add_return_op(1, volatile, pcp, val) #define this_cpu_add_return_2(pcp, val) percpu_add_return_op(2, volatile, pcp, val) #define this_cpu_add_return_4(pcp, val) percpu_add_return_op(4, volatile, pcp, val) #define this_cpu_cmpxchg_1(pcp, oval, nval) percpu_cmpxchg_op(1, volatile, pcp, oval, nval) #define this_cpu_cmpxchg_2(pcp, oval, nval) percpu_cmpxchg_op(2, volatile, pcp, oval, nval) #define this_cpu_cmpxchg_4(pcp, oval, nval) percpu_cmpxchg_op(4, volatile, pcp, oval, nval) #ifdef CONFIG_X86_CMPXCHG64 #define percpu_cmpxchg8b_double(pcp1, pcp2, o1, o2, n1, n2) \ ({ \ bool __ret; \ typeof(pcp1) __o1 = (o1), __n1 = (n1); \ typeof(pcp2) __o2 = (o2), __n2 = (n2); \ asm volatile("cmpxchg8b "__percpu_arg(1) \ CC_SET(z) \ : CC_OUT(z) (__ret), "+m" (pcp1), "+m" (pcp2), "+a" (__o1), "+d" (__o2) \ : "b" (__n1), "c" (__n2)); \ __ret; \ }) #define raw_cpu_cmpxchg_double_4 percpu_cmpxchg8b_double #define this_cpu_cmpxchg_double_4 percpu_cmpxchg8b_double #endif /* CONFIG_X86_CMPXCHG64 */ /* * Per cpu atomic 64 bit operations are only available under 64 bit. * 32 bit must fall back to generic operations. */ #ifdef CONFIG_X86_64 #define raw_cpu_read_8(pcp) percpu_from_op(8, , "mov", pcp) #define raw_cpu_write_8(pcp, val) percpu_to_op(8, , "mov", (pcp), val) #define raw_cpu_add_8(pcp, val) percpu_add_op(8, , (pcp), val) #define raw_cpu_and_8(pcp, val) percpu_to_op(8, , "and", (pcp), val) #define raw_cpu_or_8(pcp, val) percpu_to_op(8, , "or", (pcp), val) #define raw_cpu_add_return_8(pcp, val) percpu_add_return_op(8, , pcp, val) #define raw_cpu_xchg_8(pcp, nval) raw_percpu_xchg_op(pcp, nval) #define raw_cpu_cmpxchg_8(pcp, oval, nval) percpu_cmpxchg_op(8, , pcp, oval, nval) #define this_cpu_read_8(pcp) percpu_from_op(8, volatile, "mov", pcp) #define this_cpu_write_8(pcp, val) percpu_to_op(8, volatile, "mov", (pcp), val) #define this_cpu_add_8(pcp, val) percpu_add_op(8, volatile, (pcp), val) #define this_cpu_and_8(pcp, val) percpu_to_op(8, volatile, "and", (pcp), val) #define this_cpu_or_8(pcp, val) percpu_to_op(8, volatile, "or", (pcp), val) #define this_cpu_add_return_8(pcp, val) percpu_add_return_op(8, volatile, pcp, val) #define this_cpu_xchg_8(pcp, nval) percpu_xchg_op(8, volatile, pcp, nval) #define this_cpu_cmpxchg_8(pcp, oval, nval) percpu_cmpxchg_op(8, volatile, pcp, oval, nval) /* * Pretty complex macro to generate cmpxchg16 instruction. The instruction * is not supported on early AMD64 processors so we must be able to emulate * it in software. The address used in the cmpxchg16 instruction must be * aligned to a 16 byte boundary. */ #define percpu_cmpxchg16b_double(pcp1, pcp2, o1, o2, n1, n2) \ ({ \ bool __ret; \ typeof(pcp1) __o1 = (o1), __n1 = (n1); \ typeof(pcp2) __o2 = (o2), __n2 = (n2); \ alternative_io("leaq %P1,%%rsi\n\tcall this_cpu_cmpxchg16b_emu\n\t", \ "cmpxchg16b " __percpu_arg(1) "\n\tsetz %0\n\t", \ X86_FEATURE_CX16, \ ASM_OUTPUT2("=a" (__ret), "+m" (pcp1), \ "+m" (pcp2), "+d" (__o2)), \ "b" (__n1), "c" (__n2), "a" (__o1) : "rsi"); \ __ret; \ }) #define raw_cpu_cmpxchg_double_8 percpu_cmpxchg16b_double #define this_cpu_cmpxchg_double_8 percpu_cmpxchg16b_double #endif static __always_inline bool x86_this_cpu_constant_test_bit(unsigned int nr, const unsigned long __percpu *addr) { unsigned long __percpu *a = (unsigned long __percpu *)addr + nr / BITS_PER_LONG; #ifdef CONFIG_X86_64 return ((1UL << (nr % BITS_PER_LONG)) & raw_cpu_read_8(*a)) != 0; #else return ((1UL << (nr % BITS_PER_LONG)) & raw_cpu_read_4(*a)) != 0; #endif } static inline bool x86_this_cpu_variable_test_bit(int nr, const unsigned long __percpu *addr) { bool oldbit; asm volatile("btl "__percpu_arg(2)",%1" CC_SET(c) : CC_OUT(c) (oldbit) : "m" (*(unsigned long __percpu *)addr), "Ir" (nr)); return oldbit; } #define x86_this_cpu_test_bit(nr, addr) \ (__builtin_constant_p((nr)) \ ? x86_this_cpu_constant_test_bit((nr), (addr)) \ : x86_this_cpu_variable_test_bit((nr), (addr))) #include /* We can use this directly for local CPU (faster). */ DECLARE_PER_CPU_READ_MOSTLY(unsigned long, this_cpu_off); #endif /* !__ASSEMBLY__ */ #ifdef CONFIG_SMP /* * Define the "EARLY_PER_CPU" macros. These are used for some per_cpu * variables that are initialized and accessed before there are per_cpu * areas allocated. */ #define DEFINE_EARLY_PER_CPU(_type, _name, _initvalue) \ DEFINE_PER_CPU(_type, _name) = _initvalue; \ __typeof__(_type) _name##_early_map[NR_CPUS] __initdata = \ { [0 ... NR_CPUS-1] = _initvalue }; \ __typeof__(_type) *_name##_early_ptr __refdata = _name##_early_map #define DEFINE_EARLY_PER_CPU_READ_MOSTLY(_type, _name, _initvalue) \ DEFINE_PER_CPU_READ_MOSTLY(_type, _name) = _initvalue; \ __typeof__(_type) _name##_early_map[NR_CPUS] __initdata = \ { [0 ... NR_CPUS-1] = _initvalue }; \ __typeof__(_type) *_name##_early_ptr __refdata = _name##_early_map #define EXPORT_EARLY_PER_CPU_SYMBOL(_name) \ EXPORT_PER_CPU_SYMBOL(_name) #define DECLARE_EARLY_PER_CPU(_type, _name) \ DECLARE_PER_CPU(_type, _name); \ extern __typeof__(_type) *_name##_early_ptr; \ extern __typeof__(_type) _name##_early_map[] #define DECLARE_EARLY_PER_CPU_READ_MOSTLY(_type, _name) \ DECLARE_PER_CPU_READ_MOSTLY(_type, _name); \ extern __typeof__(_type) *_name##_early_ptr; \ extern __typeof__(_type) _name##_early_map[] #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)) #else /* !CONFIG_SMP */ #define DEFINE_EARLY_PER_CPU(_type, _name, _initvalue) \ DEFINE_PER_CPU(_type, _name) = _initvalue #define DEFINE_EARLY_PER_CPU_READ_MOSTLY(_type, _name, _initvalue) \ DEFINE_PER_CPU_READ_MOSTLY(_type, _name) = _initvalue #define EXPORT_EARLY_PER_CPU_SYMBOL(_name) \ EXPORT_PER_CPU_SYMBOL(_name) #define DECLARE_EARLY_PER_CPU(_type, _name) \ DECLARE_PER_CPU(_type, _name) #define DECLARE_EARLY_PER_CPU_READ_MOSTLY(_type, _name) \ DECLARE_PER_CPU_READ_MOSTLY(_type, _name) #define early_per_cpu(_name, _cpu) per_cpu(_name, _cpu) #define early_per_cpu_ptr(_name) NULL /* no early_per_cpu_map() */ #endif /* !CONFIG_SMP */ #endif /* _ASM_X86_PERCPU_H */