diff options
author | Richard Henderson <richard.henderson@linaro.org> | 2022-10-30 10:46:12 +1100 |
---|---|---|
committer | Richard Henderson <richard.henderson@linaro.org> | 2023-05-16 15:21:38 -0700 |
commit | 5b36f2684cbb07fcd75cc29b618651c43e7a80ed (patch) | |
tree | d002ffc894fe116a749b397f1da544a452e86f9d /accel | |
parent | cdfac37be0d1876832d2bb813d29df3ab885329c (diff) |
accel/tcg: Honor atomicity of stores
Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Diffstat (limited to 'accel')
-rw-r--r-- | accel/tcg/cputlb.c | 108 | ||||
-rw-r--r-- | accel/tcg/ldst_atomicity.c.inc | 491 | ||||
-rw-r--r-- | accel/tcg/user-exec.c | 12 |
3 files changed, 545 insertions, 66 deletions
diff --git a/accel/tcg/cputlb.c b/accel/tcg/cputlb.c index 33e75ae962..d910464c36 100644 --- a/accel/tcg/cputlb.c +++ b/accel/tcg/cputlb.c @@ -2599,36 +2599,6 @@ Int128 cpu_ld16_le_mmu(CPUArchState *env, abi_ptr addr, * Store Helpers */ -static inline void QEMU_ALWAYS_INLINE -store_memop(void *haddr, uint64_t val, MemOp op) -{ - switch (op) { - case MO_UB: - stb_p(haddr, val); - break; - case MO_BEUW: - stw_be_p(haddr, val); - break; - case MO_LEUW: - stw_le_p(haddr, val); - break; - case MO_BEUL: - stl_be_p(haddr, val); - break; - case MO_LEUL: - stl_le_p(haddr, val); - break; - case MO_BEUQ: - stq_be_p(haddr, val); - break; - case MO_LEUQ: - stq_le_p(haddr, val); - break; - default: - qemu_build_not_reached(); - } -} - /** * do_st_mmio_leN: * @env: cpu context @@ -2655,38 +2625,56 @@ static uint64_t do_st_mmio_leN(CPUArchState *env, MMULookupPageData *p, return val_le; } -/** - * do_st_bytes_leN: - * @p: translation parameters - * @val_le: data to store - * - * Store @p->size bytes at @p->haddr, which is RAM. - * The bytes to store are extracted in little-endian order from @val_le; - * return the bytes of @val_le beyond @p->size that have not been stored. - */ -static uint64_t do_st_bytes_leN(MMULookupPageData *p, uint64_t val_le) -{ - uint8_t *haddr = p->haddr; - int i, size = p->size; - - for (i = 0; i < size; i++, val_le >>= 8) { - haddr[i] = val_le; - } - return val_le; -} - /* * Wrapper for the above. */ static uint64_t do_st_leN(CPUArchState *env, MMULookupPageData *p, - uint64_t val_le, int mmu_idx, uintptr_t ra) + uint64_t val_le, int mmu_idx, + MemOp mop, uintptr_t ra) { + MemOp atom; + unsigned tmp, half_size; + if (unlikely(p->flags & TLB_MMIO)) { return do_st_mmio_leN(env, p, val_le, mmu_idx, ra); } else if (unlikely(p->flags & TLB_DISCARD_WRITE)) { return val_le >> (p->size * 8); - } else { - return do_st_bytes_leN(p, val_le); + } + + /* + * It is a given that we cross a page and therefore there is no atomicity + * for the store as a whole, but subobjects may need attention. + */ + atom = mop & MO_ATOM_MASK; + switch (atom) { + case MO_ATOM_SUBALIGN: + return store_parts_leN(p->haddr, p->size, val_le); + + case MO_ATOM_IFALIGN_PAIR: + case MO_ATOM_WITHIN16_PAIR: + tmp = mop & MO_SIZE; + tmp = tmp ? tmp - 1 : 0; + half_size = 1 << tmp; + if (atom == MO_ATOM_IFALIGN_PAIR + ? p->size == half_size + : p->size >= half_size) { + if (!HAVE_al8_fast && p->size <= 4) { + return store_whole_le4(p->haddr, p->size, val_le); + } else if (HAVE_al8) { + return store_whole_le8(p->haddr, p->size, val_le); + } else { + cpu_loop_exit_atomic(env_cpu(env), ra); + } + } + /* fall through */ + + case MO_ATOM_IFALIGN: + case MO_ATOM_WITHIN16: + case MO_ATOM_NONE: + return store_bytes_leN(p->haddr, p->size, val_le); + + default: + g_assert_not_reached(); } } @@ -2714,7 +2702,7 @@ static void do_st_2(CPUArchState *env, MMULookupPageData *p, uint16_t val, if (memop & MO_BSWAP) { val = bswap16(val); } - store_memop(p->haddr, val, MO_UW); + store_atom_2(env, ra, p->haddr, memop, val); } } @@ -2730,7 +2718,7 @@ static void do_st_4(CPUArchState *env, MMULookupPageData *p, uint32_t val, if (memop & MO_BSWAP) { val = bswap32(val); } - store_memop(p->haddr, val, MO_UL); + store_atom_4(env, ra, p->haddr, memop, val); } } @@ -2746,7 +2734,7 @@ static void do_st_8(CPUArchState *env, MMULookupPageData *p, uint64_t val, if (memop & MO_BSWAP) { val = bswap64(val); } - store_memop(p->haddr, val, MO_UQ); + store_atom_8(env, ra, p->haddr, memop, val); } } @@ -2815,8 +2803,8 @@ static void do_st4_mmu(CPUArchState *env, target_ulong addr, uint32_t val, if ((l.memop & MO_BSWAP) != MO_LE) { val = bswap32(val); } - val = do_st_leN(env, &l.page[0], val, l.mmu_idx, ra); - (void) do_st_leN(env, &l.page[1], val, l.mmu_idx, ra); + val = do_st_leN(env, &l.page[0], val, l.mmu_idx, l.memop, ra); + (void) do_st_leN(env, &l.page[1], val, l.mmu_idx, l.memop, ra); } void helper_le_stl_mmu(CPUArchState *env, target_ulong addr, uint32_t val, @@ -2849,8 +2837,8 @@ static void do_st8_mmu(CPUArchState *env, target_ulong addr, uint64_t val, if ((l.memop & MO_BSWAP) != MO_LE) { val = bswap64(val); } - val = do_st_leN(env, &l.page[0], val, l.mmu_idx, ra); - (void) do_st_leN(env, &l.page[1], val, l.mmu_idx, ra); + val = do_st_leN(env, &l.page[0], val, l.mmu_idx, l.memop, ra); + (void) do_st_leN(env, &l.page[1], val, l.mmu_idx, l.memop, ra); } void helper_le_stq_mmu(CPUArchState *env, target_ulong addr, uint64_t val, diff --git a/accel/tcg/ldst_atomicity.c.inc b/accel/tcg/ldst_atomicity.c.inc index a5bce641f8..1f39e43896 100644 --- a/accel/tcg/ldst_atomicity.c.inc +++ b/accel/tcg/ldst_atomicity.c.inc @@ -21,6 +21,12 @@ #else # define HAVE_al16_fast false #endif +#if defined(CONFIG_ATOMIC128) || defined(CONFIG_CMPXCHG128) +# define HAVE_al16 true +#else +# define HAVE_al16 false +#endif + /** * required_atomicity: @@ -564,3 +570,488 @@ static uint64_t load_atom_8(CPUArchState *env, uintptr_t ra, g_assert_not_reached(); } } + +/** + * store_atomic2: + * @pv: host address + * @val: value to store + * + * Atomically store 2 aligned bytes to @pv. + */ +static inline void store_atomic2(void *pv, uint16_t val) +{ + uint16_t *p = __builtin_assume_aligned(pv, 2); + qatomic_set(p, val); +} + +/** + * store_atomic4: + * @pv: host address + * @val: value to store + * + * Atomically store 4 aligned bytes to @pv. + */ +static inline void store_atomic4(void *pv, uint32_t val) +{ + uint32_t *p = __builtin_assume_aligned(pv, 4); + qatomic_set(p, val); +} + +/** + * store_atomic8: + * @pv: host address + * @val: value to store + * + * Atomically store 8 aligned bytes to @pv. + */ +static inline void store_atomic8(void *pv, uint64_t val) +{ + uint64_t *p = __builtin_assume_aligned(pv, 8); + + qemu_build_assert(HAVE_al8); + qatomic_set__nocheck(p, val); +} + +/** + * store_atom_4x2 + */ +static inline void store_atom_4_by_2(void *pv, uint32_t val) +{ + store_atomic2(pv, val >> (HOST_BIG_ENDIAN ? 16 : 0)); + store_atomic2(pv + 2, val >> (HOST_BIG_ENDIAN ? 0 : 16)); +} + +/** + * store_atom_8_by_2 + */ +static inline void store_atom_8_by_2(void *pv, uint64_t val) +{ + store_atom_4_by_2(pv, val >> (HOST_BIG_ENDIAN ? 32 : 0)); + store_atom_4_by_2(pv + 4, val >> (HOST_BIG_ENDIAN ? 0 : 32)); +} + +/** + * store_atom_8_by_4 + */ +static inline void store_atom_8_by_4(void *pv, uint64_t val) +{ + store_atomic4(pv, val >> (HOST_BIG_ENDIAN ? 32 : 0)); + store_atomic4(pv + 4, val >> (HOST_BIG_ENDIAN ? 0 : 32)); +} + +/** + * store_atom_insert_al4: + * @p: host address + * @val: shifted value to store + * @msk: mask for value to store + * + * Atomically store @val to @p, masked by @msk. + */ +static void store_atom_insert_al4(uint32_t *p, uint32_t val, uint32_t msk) +{ + uint32_t old, new; + + p = __builtin_assume_aligned(p, 4); + old = qatomic_read(p); + do { + new = (old & ~msk) | val; + } while (!__atomic_compare_exchange_n(p, &old, new, true, + __ATOMIC_RELAXED, __ATOMIC_RELAXED)); +} + +/** + * store_atom_insert_al8: + * @p: host address + * @val: shifted value to store + * @msk: mask for value to store + * + * Atomically store @val to @p masked by @msk. + */ +static void store_atom_insert_al8(uint64_t *p, uint64_t val, uint64_t msk) +{ + uint64_t old, new; + + qemu_build_assert(HAVE_al8); + p = __builtin_assume_aligned(p, 8); + old = qatomic_read__nocheck(p); + do { + new = (old & ~msk) | val; + } while (!__atomic_compare_exchange_n(p, &old, new, true, + __ATOMIC_RELAXED, __ATOMIC_RELAXED)); +} + +/** + * store_atom_insert_al16: + * @p: host address + * @val: shifted value to store + * @msk: mask for value to store + * + * Atomically store @val to @p masked by @msk. + */ +static void store_atom_insert_al16(Int128 *ps, Int128Alias val, Int128Alias msk) +{ +#if defined(CONFIG_ATOMIC128) + __uint128_t *pu, old, new; + + /* With CONFIG_ATOMIC128, we can avoid the memory barriers. */ + pu = __builtin_assume_aligned(ps, 16); + old = *pu; + do { + new = (old & ~msk.u) | val.u; + } while (!__atomic_compare_exchange_n(pu, &old, new, true, + __ATOMIC_RELAXED, __ATOMIC_RELAXED)); +#elif defined(CONFIG_CMPXCHG128) + __uint128_t *pu, old, new; + + /* + * Without CONFIG_ATOMIC128, __atomic_compare_exchange_n will always + * defer to libatomic, so we must use __sync_*_compare_and_swap_16 + * and accept the sequential consistency that comes with it. + */ + pu = __builtin_assume_aligned(ps, 16); + do { + old = *pu; + new = (old & ~msk.u) | val.u; + } while (!__sync_bool_compare_and_swap_16(pu, old, new)); +#else + qemu_build_not_reached(); +#endif +} + +/** + * store_bytes_leN: + * @pv: host address + * @size: number of bytes to store + * @val_le: data to store + * + * Store @size bytes at @p. The bytes to store are extracted in little-endian order + * from @val_le; return the bytes of @val_le beyond @size that have not been stored. + */ +static uint64_t store_bytes_leN(void *pv, int size, uint64_t val_le) +{ + uint8_t *p = pv; + for (int i = 0; i < size; i++, val_le >>= 8) { + p[i] = val_le; + } + return val_le; +} + +/** + * store_parts_leN + * @pv: host address + * @size: number of bytes to store + * @val_le: data to store + * + * As store_bytes_leN, but atomically on each aligned part. + */ +G_GNUC_UNUSED +static uint64_t store_parts_leN(void *pv, int size, uint64_t val_le) +{ + do { + int n; + + /* Find minimum of alignment and size */ + switch (((uintptr_t)pv | size) & 7) { + case 4: + store_atomic4(pv, le32_to_cpu(val_le)); + val_le >>= 32; + n = 4; + break; + case 2: + case 6: + store_atomic2(pv, le16_to_cpu(val_le)); + val_le >>= 16; + n = 2; + break; + default: + *(uint8_t *)pv = val_le; + val_le >>= 8; + n = 1; + break; + case 0: + g_assert_not_reached(); + } + pv += n; + size -= n; + } while (size != 0); + + return val_le; +} + +/** + * store_whole_le4 + * @pv: host address + * @size: number of bytes to store + * @val_le: data to store + * + * As store_bytes_leN, but atomically as a whole. + * Four aligned bytes are guaranteed to cover the store. + */ +static uint64_t store_whole_le4(void *pv, int size, uint64_t val_le) +{ + int sz = size * 8; + int o = (uintptr_t)pv & 3; + int sh = o * 8; + uint32_t m = MAKE_64BIT_MASK(0, sz); + uint32_t v; + + if (HOST_BIG_ENDIAN) { + v = bswap32(val_le) >> sh; + m = bswap32(m) >> sh; + } else { + v = val_le << sh; + m <<= sh; + } + store_atom_insert_al4(pv - o, v, m); + return val_le >> sz; +} + +/** + * store_whole_le8 + * @pv: host address + * @size: number of bytes to store + * @val_le: data to store + * + * As store_bytes_leN, but atomically as a whole. + * Eight aligned bytes are guaranteed to cover the store. + */ +static uint64_t store_whole_le8(void *pv, int size, uint64_t val_le) +{ + int sz = size * 8; + int o = (uintptr_t)pv & 7; + int sh = o * 8; + uint64_t m = MAKE_64BIT_MASK(0, sz); + uint64_t v; + + qemu_build_assert(HAVE_al8); + if (HOST_BIG_ENDIAN) { + v = bswap64(val_le) >> sh; + m = bswap64(m) >> sh; + } else { + v = val_le << sh; + m <<= sh; + } + store_atom_insert_al8(pv - o, v, m); + return val_le >> sz; +} + +/** + * store_whole_le16 + * @pv: host address + * @size: number of bytes to store + * @val_le: data to store + * + * As store_bytes_leN, but atomically as a whole. + * 16 aligned bytes are guaranteed to cover the store. + */ +static uint64_t store_whole_le16(void *pv, int size, Int128 val_le) +{ + int sz = size * 8; + int o = (uintptr_t)pv & 15; + int sh = o * 8; + Int128 m, v; + + qemu_build_assert(HAVE_al16); + + /* Like MAKE_64BIT_MASK(0, sz), but larger. */ + if (sz <= 64) { + m = int128_make64(MAKE_64BIT_MASK(0, sz)); + } else { + m = int128_make128(-1, MAKE_64BIT_MASK(0, sz - 64)); + } + + if (HOST_BIG_ENDIAN) { + v = int128_urshift(bswap128(val_le), sh); + m = int128_urshift(bswap128(m), sh); + } else { + v = int128_lshift(val_le, sh); + m = int128_lshift(m, sh); + } + store_atom_insert_al16(pv - o, v, m); + + /* Unused if sz <= 64. */ + return int128_gethi(val_le) >> (sz - 64); +} + +/** + * store_atom_2: + * @p: host address + * @val: the value to store + * @memop: the full memory op + * + * Store 2 bytes to @p, honoring the atomicity of @memop. + */ +static void store_atom_2(CPUArchState *env, uintptr_t ra, + void *pv, MemOp memop, uint16_t val) +{ + uintptr_t pi = (uintptr_t)pv; + int atmax; + + if (likely((pi & 1) == 0)) { + store_atomic2(pv, val); + return; + } + + atmax = required_atomicity(env, pi, memop); + if (atmax == MO_8) { + stw_he_p(pv, val); + return; + } + + /* + * The only case remaining is MO_ATOM_WITHIN16. + * Big or little endian, we want the middle two bytes in each test. + */ + if ((pi & 3) == 1) { + store_atom_insert_al4(pv - 1, (uint32_t)val << 8, MAKE_64BIT_MASK(8, 16)); + return; + } else if ((pi & 7) == 3) { + if (HAVE_al8) { + store_atom_insert_al8(pv - 3, (uint64_t)val << 24, MAKE_64BIT_MASK(24, 16)); + return; + } + } else if ((pi & 15) == 7) { + if (HAVE_al16) { + Int128 v = int128_lshift(int128_make64(val), 56); + Int128 m = int128_lshift(int128_make64(0xffff), 56); + store_atom_insert_al16(pv - 7, v, m); + return; + } + } else { + g_assert_not_reached(); + } + + cpu_loop_exit_atomic(env_cpu(env), ra); +} + +/** + * store_atom_4: + * @p: host address + * @val: the value to store + * @memop: the full memory op + * + * Store 4 bytes to @p, honoring the atomicity of @memop. + */ +static void store_atom_4(CPUArchState *env, uintptr_t ra, + void *pv, MemOp memop, uint32_t val) +{ + uintptr_t pi = (uintptr_t)pv; + int atmax; + + if (likely((pi & 3) == 0)) { + store_atomic4(pv, val); + return; + } + + atmax = required_atomicity(env, pi, memop); + switch (atmax) { + case MO_8: + stl_he_p(pv, val); + return; + case MO_16: + store_atom_4_by_2(pv, val); + return; + case -MO_16: + { + uint32_t val_le = cpu_to_le32(val); + int s2 = pi & 3; + int s1 = 4 - s2; + + switch (s2) { + case 1: + val_le = store_whole_le4(pv, s1, val_le); + *(uint8_t *)(pv + 3) = val_le; + break; + case 3: + *(uint8_t *)pv = val_le; + store_whole_le4(pv + 1, s2, val_le >> 8); + break; + case 0: /* aligned */ + case 2: /* atmax MO_16 */ + default: + g_assert_not_reached(); + } + } + return; + case MO_32: + if ((pi & 7) < 4) { + if (HAVE_al8) { + store_whole_le8(pv, 4, cpu_to_le32(val)); + return; + } + } else { + if (HAVE_al16) { + store_whole_le16(pv, 4, int128_make64(cpu_to_le32(val))); + return; + } + } + cpu_loop_exit_atomic(env_cpu(env), ra); + default: + g_assert_not_reached(); + } +} + +/** + * store_atom_8: + * @p: host address + * @val: the value to store + * @memop: the full memory op + * + * Store 8 bytes to @p, honoring the atomicity of @memop. + */ +static void store_atom_8(CPUArchState *env, uintptr_t ra, + void *pv, MemOp memop, uint64_t val) +{ + uintptr_t pi = (uintptr_t)pv; + int atmax; + + if (HAVE_al8 && likely((pi & 7) == 0)) { + store_atomic8(pv, val); + return; + } + + atmax = required_atomicity(env, pi, memop); + switch (atmax) { + case MO_8: + stq_he_p(pv, val); + return; + case MO_16: + store_atom_8_by_2(pv, val); + return; + case MO_32: + store_atom_8_by_4(pv, val); + return; + case -MO_32: + if (HAVE_al8) { + uint64_t val_le = cpu_to_le64(val); + int s2 = pi & 7; + int s1 = 8 - s2; + + switch (s2) { + case 1 ... 3: + val_le = store_whole_le8(pv, s1, val_le); + store_bytes_leN(pv + s1, s2, val_le); + break; + case 5 ... 7: + val_le = store_bytes_leN(pv, s1, val_le); + store_whole_le8(pv + s1, s2, val_le); + break; + case 0: /* aligned */ + case 4: /* atmax MO_32 */ + default: + g_assert_not_reached(); + } + return; + } + break; + case MO_64: + if (HAVE_al16) { + store_whole_le16(pv, 8, int128_make64(cpu_to_le64(val))); + return; + } + break; + default: + g_assert_not_reached(); + } + cpu_loop_exit_atomic(env_cpu(env), ra); +} diff --git a/accel/tcg/user-exec.c b/accel/tcg/user-exec.c index fefc83cc8c..b89fa35a83 100644 --- a/accel/tcg/user-exec.c +++ b/accel/tcg/user-exec.c @@ -1086,7 +1086,7 @@ void cpu_stw_be_mmu(CPUArchState *env, abi_ptr addr, uint16_t val, validate_memop(oi, MO_BEUW); haddr = cpu_mmu_lookup(env, addr, oi, ra, MMU_DATA_STORE); - stw_be_p(haddr, val); + store_atom_2(env, ra, haddr, get_memop(oi), be16_to_cpu(val)); clear_helper_retaddr(); qemu_plugin_vcpu_mem_cb(env_cpu(env), addr, oi, QEMU_PLUGIN_MEM_W); } @@ -1098,7 +1098,7 @@ void cpu_stl_be_mmu(CPUArchState *env, abi_ptr addr, uint32_t val, validate_memop(oi, MO_BEUL); haddr = cpu_mmu_lookup(env, addr, oi, ra, MMU_DATA_STORE); - stl_be_p(haddr, val); + store_atom_4(env, ra, haddr, get_memop(oi), be32_to_cpu(val)); clear_helper_retaddr(); qemu_plugin_vcpu_mem_cb(env_cpu(env), addr, oi, QEMU_PLUGIN_MEM_W); } @@ -1110,7 +1110,7 @@ void cpu_stq_be_mmu(CPUArchState *env, abi_ptr addr, uint64_t val, validate_memop(oi, MO_BEUQ); haddr = cpu_mmu_lookup(env, addr, oi, ra, MMU_DATA_STORE); - stq_be_p(haddr, val); + store_atom_8(env, ra, haddr, get_memop(oi), be64_to_cpu(val)); clear_helper_retaddr(); qemu_plugin_vcpu_mem_cb(env_cpu(env), addr, oi, QEMU_PLUGIN_MEM_W); } @@ -1122,7 +1122,7 @@ void cpu_stw_le_mmu(CPUArchState *env, abi_ptr addr, uint16_t val, validate_memop(oi, MO_LEUW); haddr = cpu_mmu_lookup(env, addr, oi, ra, MMU_DATA_STORE); - stw_le_p(haddr, val); + store_atom_2(env, ra, haddr, get_memop(oi), le16_to_cpu(val)); clear_helper_retaddr(); qemu_plugin_vcpu_mem_cb(env_cpu(env), addr, oi, QEMU_PLUGIN_MEM_W); } @@ -1134,7 +1134,7 @@ void cpu_stl_le_mmu(CPUArchState *env, abi_ptr addr, uint32_t val, validate_memop(oi, MO_LEUL); haddr = cpu_mmu_lookup(env, addr, oi, ra, MMU_DATA_STORE); - stl_le_p(haddr, val); + store_atom_4(env, ra, haddr, get_memop(oi), le32_to_cpu(val)); clear_helper_retaddr(); qemu_plugin_vcpu_mem_cb(env_cpu(env), addr, oi, QEMU_PLUGIN_MEM_W); } @@ -1146,7 +1146,7 @@ void cpu_stq_le_mmu(CPUArchState *env, abi_ptr addr, uint64_t val, validate_memop(oi, MO_LEUQ); haddr = cpu_mmu_lookup(env, addr, oi, ra, MMU_DATA_STORE); - stq_le_p(haddr, val); + store_atom_8(env, ra, haddr, get_memop(oi), le64_to_cpu(val)); clear_helper_retaddr(); qemu_plugin_vcpu_mem_cb(env_cpu(env), addr, oi, QEMU_PLUGIN_MEM_W); } |