/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _ASM_X86_PERCPU_H #define _ASM_X86_PERCPU_H #ifdef CONFIG_X86_64 #define __percpu_seg gs #define __percpu_mov_op movq #else #define __percpu_seg fs #define __percpu_mov_op movl #endif #ifdef __ASSEMBLY__ /* * PER_CPU finds an address of a per-cpu variable. * * Args: * var - variable name * reg - 32bit register * * The resulting address is stored in the "reg" argument. * * Example: * PER_CPU(cpu_gdt_descr, %ebx) */ #ifdef CONFIG_SMP #define PER_CPU(var, reg) \ __percpu_mov_op %__percpu_seg:this_cpu_off, reg; \ lea var(reg), reg #define PER_CPU_VAR(var) %__percpu_seg:var #else /* ! SMP */ #define PER_CPU(var, reg) __percpu_mov_op $var, reg #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 volatile("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). */ extern void __bad_percpu_size(void); #define percpu_to_op(op, var, val) \ do { \ typedef typeof(var) pto_T__; \ if (0) { \ pto_T__ pto_tmp__; \ pto_tmp__ = (val); \ (void)pto_tmp__; \ } \ switch (sizeof(var)) { \ case 1: \ asm(op "b %1,"__percpu_arg(0) \ : "+m" (var) \ : "qi" ((pto_T__)(val))); \ break; \ case 2: \ asm(op "w %1,"__percpu_arg(0) \ : "+m" (var) \ : "ri" ((pto_T__)(val))); \ break; \ case 4: \ asm(op "l %1,"__percpu_arg(0) \ : "+m" (var) \ : "ri" ((pto_T__)(val))); \ break; \ case 8: \ asm(op "q %1,"__percpu_arg(0) \ : "+m" (var) \ : "re" ((pto_T__)(val))); \ break; \ default: __bad_percpu_size(); \ } \ } while (0) /* * Generate a percpu add to memory instruction and optimize code * if one is added or subtracted. */ #define percpu_add_op(var, val) \ do { \ typedef typeof(var) pao_T__; \ const int pao_ID__ = (__builtin_constant_p(val) && \ ((val) == 1 || (val) == -1)) ? \ (int)(val) : 0; \ if (0) { \ pao_T__ pao_tmp__; \ pao_tmp__ = (val); \ (void)pao_tmp__; \ } \ switch (sizeof(var)) { \ case 1: \ if (pao_ID__ == 1) \ asm("incb "__percpu_arg(0) : "+m" (var)); \ else if (pao_ID__ == -1) \ asm("decb "__percpu_arg(0) : "+m" (var)); \ else \ asm("addb %1, "__percpu_arg(0) \ : "+m" (var) \ : "qi" ((pao_T__)(val))); \ break; \ case 2: \ if (pao_ID__ == 1) \ asm("incw "__percpu_arg(0) : "+m" (var)); \ else if (pao_ID__ == -1) \ asm("decw "__percpu_arg(0) : "+m" (var)); \ else \ asm("addw %1, "__percpu_arg(0) \ : "+m" (var) \ : "ri" ((pao_T__)(val))); \ break; \ case 4: \ if (pao_ID__ == 1) \ asm("incl "__percpu_arg(0) : "+m" (var)); \ else if (pao_ID__ == -1) \ asm("decl "__percpu_arg(0) : "+m" (var)); \ else \ asm("addl %1, "__percpu_arg(0) \ : "+m" (var) \ : "ri" ((pao_T__)(val))); \ break; \ case 8: \ if (pao_ID__ == 1) \ asm("incq "__percpu_arg(0) : "+m" (var)); \ else if (pao_ID__ == -1) \ asm("decq "__percpu_arg(0) : "+m" (var)); \ else \ asm("addq %1, "__percpu_arg(0) \ : "+m" (var) \ : "re" ((pao_T__)(val))); \ break; \ default: __bad_percpu_size(); \ } \ } while (0) #define percpu_from_op(op, var) \ ({ \ typeof(var) pfo_ret__; \ switch (sizeof(var)) { \ case 1: \ asm volatile(op "b "__percpu_arg(1)",%0"\ : "=q" (pfo_ret__) \ : "m" (var)); \ break; \ case 2: \ asm volatile(op "w "__percpu_arg(1)",%0"\ : "=r" (pfo_ret__) \ : "m" (var)); \ break; \ case 4: \ asm volatile(op "l "__percpu_arg(1)",%0"\ : "=r" (pfo_ret__) \ : "m" (var)); \ break; \ case 8: \ asm volatile(op "q "__percpu_arg(1)",%0"\ : "=r" (pfo_ret__) \ : "m" (var)); \ break; \ default: __bad_percpu_size(); \ } \ pfo_ret__; \ }) #define percpu_stable_op(op, var) \ ({ \ typeof(var) pfo_ret__; \ switch (sizeof(var)) { \ case 1: \ asm(op "b "__percpu_arg(P1)",%0" \ : "=q" (pfo_ret__) \ : "p" (&(var))); \ break; \ case 2: \ asm(op "w "__percpu_arg(P1)",%0" \ : "=r" (pfo_ret__) \ : "p" (&(var))); \ break; \ case 4: \ asm(op "l "__percpu_arg(P1)",%0" \ : "=r" (pfo_ret__) \ : "p" (&(var))); \ break; \ case 8: \ asm(op "q "__percpu_arg(P1)",%0" \ : "=r" (pfo_ret__) \ : "p" (&(var))); \ break; \ default: __bad_percpu_size(); \ } \ pfo_ret__; \ }) #define percpu_unary_op(op, var) \ ({ \ switch (sizeof(var)) { \ case 1: \ asm(op "b "__percpu_arg(0) \ : "+m" (var)); \ break; \ case 2: \ asm(op "w "__percpu_arg(0) \ : "+m" (var)); \ break; \ case 4: \ asm(op "l "__percpu_arg(0) \ : "+m" (var)); \ break; \ case 8: \ asm(op "q "__percpu_arg(0) \ : "+m" (var)); \ break; \ default: __bad_percpu_size(); \ } \ }) /* * Add return operation */ #define percpu_add_return_op(var, val) \ ({ \ typeof(var) paro_ret__ = val; \ switch (sizeof(var)) { \ case 1: \ asm("xaddb %0, "__percpu_arg(1) \ : "+q" (paro_ret__), "+m" (var) \ : : "memory"); \ break; \ case 2: \ asm("xaddw %0, "__percpu_arg(1) \ : "+r" (paro_ret__), "+m" (var) \ : : "memory"); \ break; \ case 4: \ asm("xaddl %0, "__percpu_arg(1) \ : "+r" (paro_ret__), "+m" (var) \ : : "memory"); \ break; \ case 8: \ asm("xaddq %0, "__percpu_arg(1) \ : "+re" (paro_ret__), "+m" (var) \ : : "memory"); \ break; \ default: __bad_percpu_size(); \ } \ paro_ret__ += val; \ paro_ret__; \ }) /* * 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(var, nval) \ ({ \ typeof(var) pxo_ret__; \ typeof(var) pxo_new__ = (nval); \ switch (sizeof(var)) { \ case 1: \ asm("\n\tmov "__percpu_arg(1)",%%al" \ "\n1:\tcmpxchgb %2, "__percpu_arg(1) \ "\n\tjnz 1b" \ : "=&a" (pxo_ret__), "+m" (var) \ : "q" (pxo_new__) \ : "memory"); \ break; \ case 2: \ asm("\n\tmov "__percpu_arg(1)",%%ax" \ "\n1:\tcmpxchgw %2, "__percpu_arg(1) \ "\n\tjnz 1b" \ : "=&a" (pxo_ret__), "+m" (var) \ : "r" (pxo_new__) \ : "memory"); \ break; \ case 4: \ asm("\n\tmov "__percpu_arg(1)",%%eax" \ "\n1:\tcmpxchgl %2, "__percpu_arg(1) \ "\n\tjnz 1b" \ : "=&a" (pxo_ret__), "+m" (var) \ : "r" (pxo_new__) \ : "memory"); \ break; \ case 8: \ asm("\n\tmov "__percpu_arg(1)",%%rax" \ "\n1:\tcmpxchgq %2, "__percpu_arg(1) \ "\n\tjnz 1b" \ : "=&a" (pxo_ret__), "+m" (var) \ : "r" (pxo_new__) \ : "memory"); \ break; \ default: __bad_percpu_size(); \ } \ pxo_ret__; \ }) /* * cmpxchg has no such implied lock semantics as a result it is much * more efficient for cpu local operations. */ #define percpu_cmpxchg_op(var, oval, nval) \ ({ \ typeof(var) pco_ret__; \ typeof(var) pco_old__ = (oval); \ typeof(var) pco_new__ = (nval); \ switch (sizeof(var)) { \ case 1: \ asm("cmpxchgb %2, "__percpu_arg(1) \ : "=a" (pco_ret__), "+m" (var) \ : "q" (pco_new__), "0" (pco_old__) \ : "memory"); \ break; \ case 2: \ asm("cmpxchgw %2, "__percpu_arg(1) \ : "=a" (pco_ret__), "+m" (var) \ : "r" (pco_new__), "0" (pco_old__) \ : "memory"); \ break; \ case 4: \ asm("cmpxchgl %2, "__percpu_arg(1) \ : "=a" (pco_ret__), "+m" (var) \ : "r" (pco_new__), "0" (pco_old__) \ : "memory"); \ break; \ case 8: \ asm("cmpxchgq %2, "__percpu_arg(1) \ : "=a" (pco_ret__), "+m" (var) \ : "r" (pco_new__), "0" (pco_old__) \ : "memory"); \ break; \ default: __bad_percpu_size(); \ } \ pco_ret__; \ }) /* * 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(var) percpu_stable_op("mov", var) #define raw_cpu_read_1(pcp) percpu_from_op("mov", pcp) #define raw_cpu_read_2(pcp) percpu_from_op("mov", pcp) #define raw_cpu_read_4(pcp) percpu_from_op("mov", pcp) #define raw_cpu_write_1(pcp, val) percpu_to_op("mov", (pcp), val) #define raw_cpu_write_2(pcp, val) percpu_to_op("mov", (pcp), val) #define raw_cpu_write_4(pcp, val) percpu_to_op("mov", (pcp), val) #define raw_cpu_add_1(pcp, val) percpu_add_op((pcp), val) #define raw_cpu_add_2(pcp, val) percpu_add_op((pcp), val) #define raw_cpu_add_4(pcp, val) percpu_add_op((pcp), val) #define raw_cpu_and_1(pcp, val) percpu_to_op("and", (pcp), val) #define raw_cpu_and_2(pcp, val) percpu_to_op("and", (pcp), val) #define raw_cpu_and_4(pcp, val) percpu_to_op("and", (pcp), val) #define raw_cpu_or_1(pcp, val) percpu_to_op("or", (pcp), val) #define raw_cpu_or_2(pcp, val) percpu_to_op("or", (pcp), val) #define raw_cpu_or_4(pcp, val) percpu_to_op("or", (pcp), val) #define raw_cpu_xchg_1(pcp, val) percpu_xchg_op(pcp, val) #define raw_cpu_xchg_2(pcp, val) percpu_xchg_op(pcp, val) #define raw_cpu_xchg_4(pcp, val) percpu_xchg_op(pcp, val) #define this_cpu_read_1(pcp) percpu_from_op("mov", pcp) #define this_cpu_read_2(pcp) percpu_from_op("mov", pcp) #define this_cpu_read_4(pcp) percpu_from_op("mov", pcp) #define this_cpu_write_1(pcp, val) percpu_to_op("mov", (pcp), val) #define this_cpu_write_2(pcp, val) percpu_to_op("mov", (pcp), val) #define this_cpu_write_4(pcp, val) percpu_to_op("mov", (pcp), val) #define this_cpu_add_1(pcp, val) percpu_add_op((pcp), val) #define this_cpu_add_2(pcp, val) percpu_add_op((pcp), val) #define this_cpu_add_4(pcp, val) percpu_add_op((pcp), val) #define this_cpu_and_1(pcp, val) percpu_to_op("and", (pcp), val) #define this_cpu_and_2(pcp, val) percpu_to_op("and", (pcp), val) #define this_cpu_and_4(pcp, val) percpu_to_op("and", (pcp), val) #define this_cpu_or_1(pcp, val) percpu_to_op("or", (pcp), val) #define this_cpu_or_2(pcp, val) percpu_to_op("or", (pcp), val) #define this_cpu_or_4(pcp, val) percpu_to_op("or", (pcp), val) #define this_cpu_xchg_1(pcp, nval) percpu_xchg_op(pcp, nval) #define this_cpu_xchg_2(pcp, nval) percpu_xchg_op(pcp, nval) #define this_cpu_xchg_4(pcp, nval) percpu_xchg_op(pcp, nval) #define raw_cpu_add_return_1(pcp, val) percpu_add_return_op(pcp, val) #define raw_cpu_add_return_2(pcp, val) percpu_add_return_op(pcp, val) #define raw_cpu_add_return_4(pcp, val) percpu_add_return_op(pcp, val) #define raw_cpu_cmpxchg_1(pcp, oval, nval) percpu_cmpxchg_op(pcp, oval, nval) #define raw_cpu_cmpxchg_2(pcp, oval, nval) percpu_cmpxchg_op(pcp, oval, nval) #define raw_cpu_cmpxchg_4(pcp, oval, nval) percpu_cmpxchg_op(pcp, oval, nval) #define this_cpu_add_return_1(pcp, val) percpu_add_return_op(pcp, val) #define this_cpu_add_return_2(pcp, val) percpu_add_return_op(pcp, val) #define this_cpu_add_return_4(pcp, val) percpu_add_return_op(pcp, val) #define this_cpu_cmpxchg_1(pcp, oval, nval) percpu_cmpxchg_op(pcp, oval, nval) #define this_cpu_cmpxchg_2(pcp, oval, nval) percpu_cmpxchg_op(pcp, oval, nval) #define this_cpu_cmpxchg_4(pcp, oval, nval) percpu_cmpxchg_op(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("mov", pcp) #define raw_cpu_write_8(pcp, val) percpu_to_op("mov", (pcp), val) #define raw_cpu_add_8(pcp, val) percpu_add_op((pcp), val) #define raw_cpu_and_8(pcp, val) percpu_to_op("and", (pcp), val) #define raw_cpu_or_8(pcp, val) percpu_to_op("or", (pcp), val) #define raw_cpu_add_return_8(pcp, val) percpu_add_return_op(pcp, val) #define raw_cpu_xchg_8(pcp, nval) percpu_xchg_op(pcp, nval) #define raw_cpu_cmpxchg_8(pcp, oval, nval) percpu_cmpxchg_op(pcp, oval, nval) #define this_cpu_read_8(pcp) percpu_from_op("mov", pcp) #define this_cpu_write_8(pcp, val) percpu_to_op("mov", (pcp), val) #define this_cpu_add_8(pcp, val) percpu_add_op((pcp), val) #define this_cpu_and_8(pcp, val) percpu_to_op("and", (pcp), val) #define this_cpu_or_8(pcp, val) percpu_to_op("or", (pcp), val) #define this_cpu_add_return_8(pcp, val) percpu_add_return_op(pcp, val) #define this_cpu_xchg_8(pcp, nval) percpu_xchg_op(pcp, nval) #define this_cpu_cmpxchg_8(pcp, oval, nval) percpu_cmpxchg_op(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 */