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Diffstat (limited to 'arch/arm64/include/asm/percpu.h')
-rw-r--r-- | arch/arm64/include/asm/percpu.h | 311 |
1 files changed, 311 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/percpu.h b/arch/arm64/include/asm/percpu.h new file mode 100644 index 000000000..21a81b59a --- /dev/null +++ b/arch/arm64/include/asm/percpu.h @@ -0,0 +1,311 @@ +/* + * Copyright (C) 2013 ARM Ltd. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program. If not, see <http://www.gnu.org/licenses/>. + */ +#ifndef __ASM_PERCPU_H +#define __ASM_PERCPU_H + +#include <linux/preempt.h> + +#include <asm/alternative.h> +#include <asm/cmpxchg.h> +#include <asm/stack_pointer.h> + +static inline void set_my_cpu_offset(unsigned long off) +{ + asm volatile(ALTERNATIVE("msr tpidr_el1, %0", + "msr tpidr_el2, %0", + ARM64_HAS_VIRT_HOST_EXTN) + :: "r" (off) : "memory"); +} + +static inline unsigned long __my_cpu_offset(void) +{ + unsigned long off; + + /* + * We want to allow caching the value, so avoid using volatile and + * instead use a fake stack read to hazard against barrier(). + */ + asm(ALTERNATIVE("mrs %0, tpidr_el1", + "mrs %0, tpidr_el2", + ARM64_HAS_VIRT_HOST_EXTN) + : "=r" (off) : + "Q" (*(const unsigned long *)current_stack_pointer)); + + return off; +} +#define __my_cpu_offset __my_cpu_offset() + +#define PERCPU_OP(op, asm_op) \ +static inline unsigned long __percpu_##op(void *ptr, \ + unsigned long val, int size) \ +{ \ + unsigned long loop, ret; \ + \ + switch (size) { \ + case 1: \ + asm ("//__per_cpu_" #op "_1\n" \ + "1: ldxrb %w[ret], %[ptr]\n" \ + #asm_op " %w[ret], %w[ret], %w[val]\n" \ + " stxrb %w[loop], %w[ret], %[ptr]\n" \ + " cbnz %w[loop], 1b" \ + : [loop] "=&r" (loop), [ret] "=&r" (ret), \ + [ptr] "+Q"(*(u8 *)ptr) \ + : [val] "Ir" (val)); \ + break; \ + case 2: \ + asm ("//__per_cpu_" #op "_2\n" \ + "1: ldxrh %w[ret], %[ptr]\n" \ + #asm_op " %w[ret], %w[ret], %w[val]\n" \ + " stxrh %w[loop], %w[ret], %[ptr]\n" \ + " cbnz %w[loop], 1b" \ + : [loop] "=&r" (loop), [ret] "=&r" (ret), \ + [ptr] "+Q"(*(u16 *)ptr) \ + : [val] "Ir" (val)); \ + break; \ + case 4: \ + asm ("//__per_cpu_" #op "_4\n" \ + "1: ldxr %w[ret], %[ptr]\n" \ + #asm_op " %w[ret], %w[ret], %w[val]\n" \ + " stxr %w[loop], %w[ret], %[ptr]\n" \ + " cbnz %w[loop], 1b" \ + : [loop] "=&r" (loop), [ret] "=&r" (ret), \ + [ptr] "+Q"(*(u32 *)ptr) \ + : [val] "Ir" (val)); \ + break; \ + case 8: \ + asm ("//__per_cpu_" #op "_8\n" \ + "1: ldxr %[ret], %[ptr]\n" \ + #asm_op " %[ret], %[ret], %[val]\n" \ + " stxr %w[loop], %[ret], %[ptr]\n" \ + " cbnz %w[loop], 1b" \ + : [loop] "=&r" (loop), [ret] "=&r" (ret), \ + [ptr] "+Q"(*(u64 *)ptr) \ + : [val] "Ir" (val)); \ + break; \ + default: \ + ret = 0; \ + BUILD_BUG(); \ + } \ + \ + return ret; \ +} + +PERCPU_OP(add, add) +PERCPU_OP(and, and) +PERCPU_OP(or, orr) +#undef PERCPU_OP + +static inline unsigned long __percpu_read(void *ptr, int size) +{ + unsigned long ret; + + switch (size) { + case 1: + ret = READ_ONCE(*(u8 *)ptr); + break; + case 2: + ret = READ_ONCE(*(u16 *)ptr); + break; + case 4: + ret = READ_ONCE(*(u32 *)ptr); + break; + case 8: + ret = READ_ONCE(*(u64 *)ptr); + break; + default: + ret = 0; + BUILD_BUG(); + } + + return ret; +} + +static inline void __percpu_write(void *ptr, unsigned long val, int size) +{ + switch (size) { + case 1: + WRITE_ONCE(*(u8 *)ptr, (u8)val); + break; + case 2: + WRITE_ONCE(*(u16 *)ptr, (u16)val); + break; + case 4: + WRITE_ONCE(*(u32 *)ptr, (u32)val); + break; + case 8: + WRITE_ONCE(*(u64 *)ptr, (u64)val); + break; + default: + BUILD_BUG(); + } +} + +static inline unsigned long __percpu_xchg(void *ptr, unsigned long val, + int size) +{ + unsigned long ret, loop; + + switch (size) { + case 1: + asm ("//__percpu_xchg_1\n" + "1: ldxrb %w[ret], %[ptr]\n" + " stxrb %w[loop], %w[val], %[ptr]\n" + " cbnz %w[loop], 1b" + : [loop] "=&r"(loop), [ret] "=&r"(ret), + [ptr] "+Q"(*(u8 *)ptr) + : [val] "r" (val)); + break; + case 2: + asm ("//__percpu_xchg_2\n" + "1: ldxrh %w[ret], %[ptr]\n" + " stxrh %w[loop], %w[val], %[ptr]\n" + " cbnz %w[loop], 1b" + : [loop] "=&r"(loop), [ret] "=&r"(ret), + [ptr] "+Q"(*(u16 *)ptr) + : [val] "r" (val)); + break; + case 4: + asm ("//__percpu_xchg_4\n" + "1: ldxr %w[ret], %[ptr]\n" + " stxr %w[loop], %w[val], %[ptr]\n" + " cbnz %w[loop], 1b" + : [loop] "=&r"(loop), [ret] "=&r"(ret), + [ptr] "+Q"(*(u32 *)ptr) + : [val] "r" (val)); + break; + case 8: + asm ("//__percpu_xchg_8\n" + "1: ldxr %[ret], %[ptr]\n" + " stxr %w[loop], %[val], %[ptr]\n" + " cbnz %w[loop], 1b" + : [loop] "=&r"(loop), [ret] "=&r"(ret), + [ptr] "+Q"(*(u64 *)ptr) + : [val] "r" (val)); + break; + default: + ret = 0; + BUILD_BUG(); + } + + return ret; +} + +/* this_cpu_cmpxchg */ +#define _protect_cmpxchg_local(pcp, o, n) \ +({ \ + typeof(*raw_cpu_ptr(&(pcp))) __ret; \ + preempt_disable(); \ + __ret = cmpxchg_local(raw_cpu_ptr(&(pcp)), o, n); \ + preempt_enable(); \ + __ret; \ +}) + +#define this_cpu_cmpxchg_1(ptr, o, n) _protect_cmpxchg_local(ptr, o, n) +#define this_cpu_cmpxchg_2(ptr, o, n) _protect_cmpxchg_local(ptr, o, n) +#define this_cpu_cmpxchg_4(ptr, o, n) _protect_cmpxchg_local(ptr, o, n) +#define this_cpu_cmpxchg_8(ptr, o, n) _protect_cmpxchg_local(ptr, o, n) + +#define this_cpu_cmpxchg_double_8(ptr1, ptr2, o1, o2, n1, n2) \ +({ \ + int __ret; \ + preempt_disable(); \ + __ret = cmpxchg_double_local( raw_cpu_ptr(&(ptr1)), \ + raw_cpu_ptr(&(ptr2)), \ + o1, o2, n1, n2); \ + preempt_enable(); \ + __ret; \ +}) + +#define _percpu_read(pcp) \ +({ \ + typeof(pcp) __retval; \ + preempt_disable_notrace(); \ + __retval = (typeof(pcp))__percpu_read(raw_cpu_ptr(&(pcp)), \ + sizeof(pcp)); \ + preempt_enable_notrace(); \ + __retval; \ +}) + +#define _percpu_write(pcp, val) \ +do { \ + preempt_disable_notrace(); \ + __percpu_write(raw_cpu_ptr(&(pcp)), (unsigned long)(val), \ + sizeof(pcp)); \ + preempt_enable_notrace(); \ +} while(0) \ + +#define _pcp_protect(operation, pcp, val) \ +({ \ + typeof(pcp) __retval; \ + preempt_disable(); \ + __retval = (typeof(pcp))operation(raw_cpu_ptr(&(pcp)), \ + (val), sizeof(pcp)); \ + preempt_enable(); \ + __retval; \ +}) + +#define _percpu_add(pcp, val) \ + _pcp_protect(__percpu_add, pcp, val) + +#define _percpu_add_return(pcp, val) _percpu_add(pcp, val) + +#define _percpu_and(pcp, val) \ + _pcp_protect(__percpu_and, pcp, val) + +#define _percpu_or(pcp, val) \ + _pcp_protect(__percpu_or, pcp, val) + +#define _percpu_xchg(pcp, val) (typeof(pcp)) \ + _pcp_protect(__percpu_xchg, pcp, (unsigned long)(val)) + +#define this_cpu_add_1(pcp, val) _percpu_add(pcp, val) +#define this_cpu_add_2(pcp, val) _percpu_add(pcp, val) +#define this_cpu_add_4(pcp, val) _percpu_add(pcp, val) +#define this_cpu_add_8(pcp, val) _percpu_add(pcp, val) + +#define this_cpu_add_return_1(pcp, val) _percpu_add_return(pcp, val) +#define this_cpu_add_return_2(pcp, val) _percpu_add_return(pcp, val) +#define this_cpu_add_return_4(pcp, val) _percpu_add_return(pcp, val) +#define this_cpu_add_return_8(pcp, val) _percpu_add_return(pcp, val) + +#define this_cpu_and_1(pcp, val) _percpu_and(pcp, val) +#define this_cpu_and_2(pcp, val) _percpu_and(pcp, val) +#define this_cpu_and_4(pcp, val) _percpu_and(pcp, val) +#define this_cpu_and_8(pcp, val) _percpu_and(pcp, val) + +#define this_cpu_or_1(pcp, val) _percpu_or(pcp, val) +#define this_cpu_or_2(pcp, val) _percpu_or(pcp, val) +#define this_cpu_or_4(pcp, val) _percpu_or(pcp, val) +#define this_cpu_or_8(pcp, val) _percpu_or(pcp, val) + +#define this_cpu_read_1(pcp) _percpu_read(pcp) +#define this_cpu_read_2(pcp) _percpu_read(pcp) +#define this_cpu_read_4(pcp) _percpu_read(pcp) +#define this_cpu_read_8(pcp) _percpu_read(pcp) + +#define this_cpu_write_1(pcp, val) _percpu_write(pcp, val) +#define this_cpu_write_2(pcp, val) _percpu_write(pcp, val) +#define this_cpu_write_4(pcp, val) _percpu_write(pcp, val) +#define this_cpu_write_8(pcp, val) _percpu_write(pcp, val) + +#define this_cpu_xchg_1(pcp, val) _percpu_xchg(pcp, val) +#define this_cpu_xchg_2(pcp, val) _percpu_xchg(pcp, val) +#define this_cpu_xchg_4(pcp, val) _percpu_xchg(pcp, val) +#define this_cpu_xchg_8(pcp, val) _percpu_xchg(pcp, val) + +#include <asm-generic/percpu.h> + +#endif /* __ASM_PERCPU_H */ |