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authorRichard Henderson <richard.henderson@linaro.org>2020-01-29 15:50:37 -0800
committerDavid Gibson <david@gibson.dropbear.id.au>2020-02-03 11:33:11 +1100
commitbb99b391896f3c7a477777e3d47a2524fd795357 (patch)
tree7c1724ccad381e96ba8f7207cce2f0491de725c5 /target/ppc
parente0aeef7a3532a7abe921ea96c6a1e974f2ab1fa1 (diff)
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 <hsp.cat7@gmail.com> Signed-off-by: Richard Henderson <richard.henderson@linaro.org> Message-Id: <20200129235040.24022-2-richard.henderson@linaro.org> Tested-by: Howard Spoelstra <hsp.cat7@gmail.com> Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Diffstat (limited to 'target/ppc')
-rw-r--r--target/ppc/mem_helper.c148
1 files 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;
}
}
}