^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 1) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 2) * 1,2 and 4 byte cmpxchg and xchg implementations for OpenRISC.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 3) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 4) * Copyright (C) 2014 Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 5) * Copyright (C) 2017 Stafford Horne <shorne@gmail.com>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 6) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 7) * This file is licensed under the terms of the GNU General Public License
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 8) * version 2. This program is licensed "as is" without any warranty of any
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 9) * kind, whether express or implied.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) * Note:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) * The portable implementations of 1 and 2 byte xchg and cmpxchg using a 4
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) * byte cmpxchg is sourced heavily from the sh and mips implementations.
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) #ifndef __ASM_OPENRISC_CMPXCHG_H
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) #define __ASM_OPENRISC_CMPXCHG_H
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) #include <linux/bits.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) #include <linux/compiler.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) #include <linux/types.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) #define __HAVE_ARCH_CMPXCHG 1
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) static inline unsigned long cmpxchg_u32(volatile void *ptr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) unsigned long old, unsigned long new)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) __asm__ __volatile__(
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) "1: l.lwa %0, 0(%1) \n"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) " l.sfeq %0, %2 \n"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) " l.bnf 2f \n"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) " l.nop \n"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) " l.swa 0(%1), %3 \n"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) " l.bnf 1b \n"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) " l.nop \n"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) "2: \n"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) : "=&r"(old)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) : "r"(ptr), "r"(old), "r"(new)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) : "cc", "memory");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) return old;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) static inline unsigned long xchg_u32(volatile void *ptr,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) unsigned long val)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) __asm__ __volatile__(
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) "1: l.lwa %0, 0(%1) \n"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) " l.swa 0(%1), %2 \n"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) " l.bnf 1b \n"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) " l.nop \n"
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) : "=&r"(val)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) : "r"(ptr), "r"(val)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) : "cc", "memory");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) return val;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) static inline u32 cmpxchg_small(volatile void *ptr, u32 old, u32 new,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) int size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) int off = (unsigned long)ptr % sizeof(u32);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) volatile u32 *p = ptr - off;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) #ifdef __BIG_ENDIAN
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) int bitoff = (sizeof(u32) - size - off) * BITS_PER_BYTE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) int bitoff = off * BITS_PER_BYTE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) u32 bitmask = ((0x1 << size * BITS_PER_BYTE) - 1) << bitoff;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) u32 load32, old32, new32;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) u32 ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) load32 = READ_ONCE(*p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 75) while (true) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 76) ret = (load32 & bitmask) >> bitoff;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 77) if (old != ret)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 78) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 79)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 80) old32 = (load32 & ~bitmask) | (old << bitoff);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 81) new32 = (load32 & ~bitmask) | (new << bitoff);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 82)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 83) /* Do 32 bit cmpxchg */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 84) load32 = cmpxchg_u32(p, old32, new32);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 85) if (load32 == old32)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 86) return old;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 87) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 88) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 89)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 90) /* xchg */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 91)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 92) static inline u32 xchg_small(volatile void *ptr, u32 x, int size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 93) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 94) int off = (unsigned long)ptr % sizeof(u32);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 95) volatile u32 *p = ptr - off;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 96) #ifdef __BIG_ENDIAN
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 97) int bitoff = (sizeof(u32) - size - off) * BITS_PER_BYTE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 98) #else
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 99) int bitoff = off * BITS_PER_BYTE;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 100) #endif
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 101) u32 bitmask = ((0x1 << size * BITS_PER_BYTE) - 1) << bitoff;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 102) u32 oldv, newv;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 103) u32 ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 104)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 105) do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 106) oldv = READ_ONCE(*p);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 107) ret = (oldv & bitmask) >> bitoff;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 108) newv = (oldv & ~bitmask) | (x << bitoff);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 109) } while (cmpxchg_u32(p, oldv, newv) != oldv);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 110)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 111) return ret;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 112) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 113)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 114) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 115) * This function doesn't exist, so you'll get a linker error
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 116) * if something tries to do an invalid cmpxchg().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 117) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 118) extern unsigned long __cmpxchg_called_with_bad_pointer(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 119) __compiletime_error("Bad argument size for cmpxchg");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 120)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 121) static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 122) unsigned long new, int size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 123) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 124) switch (size) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 125) case 1:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 126) case 2:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 127) return cmpxchg_small(ptr, old, new, size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 128) case 4:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 129) return cmpxchg_u32(ptr, old, new);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 130) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 131) return __cmpxchg_called_with_bad_pointer();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 132) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 133) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 134)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 135) #define cmpxchg(ptr, o, n) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 136) ({ \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 137) (__typeof__(*(ptr))) __cmpxchg((ptr), \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 138) (unsigned long)(o), \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 139) (unsigned long)(n), \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 140) sizeof(*(ptr))); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 141) })
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 142)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 143) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 144) * This function doesn't exist, so you'll get a linker error if
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 145) * something tries to do an invalidly-sized xchg().
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 146) */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 147) extern unsigned long __xchg_called_with_bad_pointer(void)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 148) __compiletime_error("Bad argument size for xchg");
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 149)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 150) static inline unsigned long __xchg(volatile void *ptr, unsigned long with,
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 151) int size)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 152) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 153) switch (size) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 154) case 1:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 155) case 2:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 156) return xchg_small(ptr, with, size);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 157) case 4:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 158) return xchg_u32(ptr, with);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 159) default:
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 160) return __xchg_called_with_bad_pointer();
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 161) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 162) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 163)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 164) #define xchg(ptr, with) \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 165) ({ \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 166) (__typeof__(*(ptr))) __xchg((ptr), \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 167) (unsigned long)(with), \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 168) sizeof(*(ptr))); \
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 169) })
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 170)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 171) #endif /* __ASM_OPENRISC_CMPXCHG_H */
Orange Pi5 kernel
Deprecated Linux kernel 5.10.110 for OrangePi 5/5B/5+ boards
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