From bb99b391896f3c7a477777e3d47a2524fd795357 Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Wed, 29 Jan 2020 15:50:37 -0800 Subject: [PATCH] target/ppc: Use probe_access for LSW, STSW Use a minimum number of mmu lookups for the contiguous bytes that are accessed. If the lookup succeeds, we can finish the operation with host addresses only. Reported-by: Howard Spoelstra Signed-off-by: Richard Henderson Message-Id: <20200129235040.24022-2-richard.henderson@linaro.org> Tested-by: Howard Spoelstra Signed-off-by: David Gibson --- target/ppc/mem_helper.c | 148 +++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 128 insertions(+), 20 deletions(-) diff --git a/target/ppc/mem_helper.c b/target/ppc/mem_helper.c index e8e2a8ac2a..508d472a2f 100644 --- a/target/ppc/mem_helper.c +++ b/target/ppc/mem_helper.c @@ -56,6 +56,32 @@ static inline target_ulong addr_add(CPUPPCState *env, target_ulong addr, } } +static void *probe_contiguous(CPUPPCState *env, target_ulong addr, uint32_t nb, + MMUAccessType access_type, int mmu_idx, + uintptr_t raddr) +{ + void *host1, *host2; + uint32_t nb_pg1, nb_pg2; + + nb_pg1 = -(addr | TARGET_PAGE_MASK); + if (likely(nb <= nb_pg1)) { + /* The entire operation is on a single page. */ + return probe_access(env, addr, nb, access_type, mmu_idx, raddr); + } + + /* The operation spans two pages. */ + nb_pg2 = nb - nb_pg1; + host1 = probe_access(env, addr, nb_pg1, access_type, mmu_idx, raddr); + addr = addr_add(env, addr, nb_pg1); + host2 = probe_access(env, addr, nb_pg2, access_type, mmu_idx, raddr); + + /* If the two host pages are contiguous, optimize. */ + if (host2 == host1 + nb_pg1) { + return host1; + } + return NULL; +} + void helper_lmw(CPUPPCState *env, target_ulong addr, uint32_t reg) { for (; reg < 32; reg++) { @@ -84,23 +110,65 @@ void helper_stmw(CPUPPCState *env, target_ulong addr, uint32_t reg) static void do_lsw(CPUPPCState *env, target_ulong addr, uint32_t nb, uint32_t reg, uintptr_t raddr) { - int sh; + int mmu_idx; + void *host; + uint32_t val; - for (; nb > 3; nb -= 4) { - env->gpr[reg] = cpu_ldl_data_ra(env, addr, raddr); - reg = (reg + 1) % 32; - addr = addr_add(env, addr, 4); + if (unlikely(nb == 0)) { + return; } - if (unlikely(nb > 0)) { - env->gpr[reg] = 0; - for (sh = 24; nb > 0; nb--, sh -= 8) { - env->gpr[reg] |= cpu_ldub_data_ra(env, addr, raddr) << sh; - addr = addr_add(env, addr, 1); + + mmu_idx = cpu_mmu_index(env, false); + host = probe_contiguous(env, addr, nb, MMU_DATA_LOAD, mmu_idx, raddr); + + if (likely(host)) { + /* Fast path -- the entire operation is in RAM at host. */ + for (; nb > 3; nb -= 4) { + env->gpr[reg] = (uint32_t)ldl_be_p(host); + reg = (reg + 1) % 32; + host += 4; + } + switch (nb) { + default: + return; + case 1: + val = ldub_p(host) << 24; + break; + case 2: + val = lduw_be_p(host) << 16; + break; + case 3: + val = (lduw_be_p(host) << 16) | (ldub_p(host + 2) << 8); + break; + } + } else { + /* Slow path -- at least some of the operation requires i/o. */ + for (; nb > 3; nb -= 4) { + env->gpr[reg] = cpu_ldl_mmuidx_ra(env, addr, mmu_idx, raddr); + reg = (reg + 1) % 32; + addr = addr_add(env, addr, 4); + } + switch (nb) { + default: + return; + case 1: + val = cpu_ldub_mmuidx_ra(env, addr, mmu_idx, raddr) << 24; + break; + case 2: + val = cpu_lduw_mmuidx_ra(env, addr, mmu_idx, raddr) << 16; + break; + case 3: + val = cpu_lduw_mmuidx_ra(env, addr, mmu_idx, raddr) << 16; + addr = addr_add(env, addr, 2); + val |= cpu_ldub_mmuidx_ra(env, addr, mmu_idx, raddr) << 8; + break; } } + env->gpr[reg] = val; } -void helper_lsw(CPUPPCState *env, target_ulong addr, uint32_t nb, uint32_t reg) +void helper_lsw(CPUPPCState *env, target_ulong addr, + uint32_t nb, uint32_t reg) { do_lsw(env, addr, nb, reg, GETPC()); } @@ -130,17 +198,57 @@ void helper_lswx(CPUPPCState *env, target_ulong addr, uint32_t reg, void helper_stsw(CPUPPCState *env, target_ulong addr, uint32_t nb, uint32_t reg) { - int sh; + uintptr_t raddr = GETPC(); + int mmu_idx; + void *host; + uint32_t val; - for (; nb > 3; nb -= 4) { - cpu_stl_data_ra(env, addr, env->gpr[reg], GETPC()); - reg = (reg + 1) % 32; - addr = addr_add(env, addr, 4); + if (unlikely(nb == 0)) { + return; } - if (unlikely(nb > 0)) { - for (sh = 24; nb > 0; nb--, sh -= 8) { - cpu_stb_data_ra(env, addr, (env->gpr[reg] >> sh) & 0xFF, GETPC()); - addr = addr_add(env, addr, 1); + + mmu_idx = cpu_mmu_index(env, false); + host = probe_contiguous(env, addr, nb, MMU_DATA_STORE, mmu_idx, raddr); + + if (likely(host)) { + /* Fast path -- the entire operation is in RAM at host. */ + for (; nb > 3; nb -= 4) { + stl_be_p(host, env->gpr[reg]); + reg = (reg + 1) % 32; + host += 4; + } + val = env->gpr[reg]; + switch (nb) { + case 1: + stb_p(host, val >> 24); + break; + case 2: + stw_be_p(host, val >> 16); + break; + case 3: + stw_be_p(host, val >> 16); + stb_p(host + 2, val >> 8); + break; + } + } else { + for (; nb > 3; nb -= 4) { + cpu_stl_mmuidx_ra(env, addr, env->gpr[reg], mmu_idx, raddr); + reg = (reg + 1) % 32; + addr = addr_add(env, addr, 4); + } + val = env->gpr[reg]; + switch (nb) { + case 1: + cpu_stb_mmuidx_ra(env, addr, val >> 24, mmu_idx, raddr); + break; + case 2: + cpu_stw_mmuidx_ra(env, addr, val >> 16, mmu_idx, raddr); + break; + case 3: + cpu_stw_mmuidx_ra(env, addr, val >> 16, mmu_idx, raddr); + addr = addr_add(env, addr, 2); + cpu_stb_mmuidx_ra(env, addr, val >> 8, mmu_idx, raddr); + break; } } } -- 2.11.4.GIT