From: Richard Henderson <richard.henderson@linaro.org>
To: qemu-devel@nongnu.org
Cc: alistair23@gmail.com, qemu-riscv@nongnu.org,
Alistair Francis <alistair.francis@wdc.com>,
Weiwei Li <liweiwei@iscas.ac.cn>,
Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Subject: [PATCH v7 20/25] target/riscv: Move leaf pte processing out of level loop
Date: Wed, 12 Apr 2023 13:43:28 +0200 [thread overview]
Message-ID: <20230412114333.118895-21-richard.henderson@linaro.org> (raw)
In-Reply-To: <20230412114333.118895-1-richard.henderson@linaro.org>
Move the code that never loops outside of the loop.
Unchain the if-return-else statements.
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Reviewed-by: Weiwei Li <liweiwei@iscas.ac.cn>
Tested-by: Daniel Henrique Barboza <dbarboza@ventanamicro.com>
Message-Id: <20230325105429.1142530-21-richard.henderson@linaro.org>
---
target/riscv/cpu_helper.c | 238 ++++++++++++++++++++------------------
1 file changed, 125 insertions(+), 113 deletions(-)
diff --git a/target/riscv/cpu_helper.c b/target/riscv/cpu_helper.c
index 7c9f89d4d3..c2d083f029 100644
--- a/target/riscv/cpu_helper.c
+++ b/target/riscv/cpu_helper.c
@@ -865,6 +865,8 @@ static int get_physical_address(CPURISCVState *env, hwaddr *physical,
}
int ptshift = (levels - 1) * ptidxbits;
+ target_ulong pte;
+ hwaddr pte_addr;
int i;
#if !TCG_OVERSIZED_GUEST
@@ -881,7 +883,6 @@ restart:
}
/* check that physical address of PTE is legal */
- hwaddr pte_addr;
if (two_stage && first_stage) {
int vbase_prot;
@@ -913,7 +914,6 @@ restart:
return TRANSLATE_PMP_FAIL;
}
- target_ulong pte;
if (riscv_cpu_mxl(env) == MXL_RV32) {
pte = address_space_ldl(cs->as, pte_addr, attrs, &res);
} else {
@@ -938,128 +938,140 @@ restart:
if (!(pte & PTE_V)) {
/* Invalid PTE */
return TRANSLATE_FAIL;
- } else if (!pbmte && (pte & PTE_PBMT)) {
+ }
+ if (pte & (PTE_R | PTE_W | PTE_X)) {
+ goto leaf;
+ }
+
+ /* Inner PTE, continue walking */
+ if (pte & (PTE_D | PTE_A | PTE_U | PTE_ATTR)) {
return TRANSLATE_FAIL;
- } else if (!(pte & (PTE_R | PTE_W | PTE_X))) {
- /* Inner PTE, continue walking */
- if (pte & (PTE_D | PTE_A | PTE_U | PTE_ATTR)) {
- return TRANSLATE_FAIL;
- }
- base = ppn << PGSHIFT;
- } else if ((pte & (PTE_R | PTE_W | PTE_X)) == PTE_W) {
- /* Reserved leaf PTE flags: PTE_W */
- return TRANSLATE_FAIL;
- } else if ((pte & (PTE_R | PTE_W | PTE_X)) == (PTE_W | PTE_X)) {
- /* Reserved leaf PTE flags: PTE_W + PTE_X */
- return TRANSLATE_FAIL;
- } else if ((pte & PTE_U) && ((mode != PRV_U) &&
- (!sum || access_type == MMU_INST_FETCH))) {
- /* User PTE flags when not U mode and mstatus.SUM is not set,
- or the access type is an instruction fetch */
- return TRANSLATE_FAIL;
- } else if (!(pte & PTE_U) && (mode != PRV_S)) {
- /* Supervisor PTE flags when not S mode */
- return TRANSLATE_FAIL;
- } else if (ppn & ((1ULL << ptshift) - 1)) {
- /* Misaligned PPN */
- return TRANSLATE_FAIL;
- } else if (access_type == MMU_DATA_LOAD && !((pte & PTE_R) ||
- ((pte & PTE_X) && mxr))) {
- /* Read access check failed */
- return TRANSLATE_FAIL;
- } else if (access_type == MMU_DATA_STORE && !(pte & PTE_W)) {
- /* Write access check failed */
- return TRANSLATE_FAIL;
- } else if (access_type == MMU_INST_FETCH && !(pte & PTE_X)) {
- /* Fetch access check failed */
- return TRANSLATE_FAIL;
- } else {
- /* if necessary, set accessed and dirty bits. */
- target_ulong updated_pte = pte | PTE_A |
+ }
+ base = ppn << PGSHIFT;
+ }
+
+ /* No leaf pte at any translation level. */
+ return TRANSLATE_FAIL;
+
+ leaf:
+ if (ppn & ((1ULL << ptshift) - 1)) {
+ /* Misaligned PPN */
+ return TRANSLATE_FAIL;
+ }
+ if (!pbmte && (pte & PTE_PBMT)) {
+ /* Reserved without Svpbmt. */
+ return TRANSLATE_FAIL;
+ }
+ if ((pte & (PTE_R | PTE_W | PTE_X)) == PTE_W) {
+ /* Reserved leaf PTE flags: PTE_W */
+ return TRANSLATE_FAIL;
+ }
+ if ((pte & (PTE_R | PTE_W | PTE_X)) == (PTE_W | PTE_X)) {
+ /* Reserved leaf PTE flags: PTE_W + PTE_X */
+ return TRANSLATE_FAIL;
+ }
+ if ((pte & PTE_U) &&
+ ((mode != PRV_U) && (!sum || access_type == MMU_INST_FETCH))) {
+ /*
+ * User PTE flags when not U mode and mstatus.SUM is not set,
+ * or the access type is an instruction fetch.
+ */
+ return TRANSLATE_FAIL;
+ }
+ if (!(pte & PTE_U) && (mode != PRV_S)) {
+ /* Supervisor PTE flags when not S mode */
+ return TRANSLATE_FAIL;
+ }
+ if (access_type == MMU_DATA_LOAD &&
+ !((pte & PTE_R) || ((pte & PTE_X) && mxr))) {
+ /* Read access check failed */
+ return TRANSLATE_FAIL;
+ }
+ if (access_type == MMU_DATA_STORE && !(pte & PTE_W)) {
+ /* Write access check failed */
+ return TRANSLATE_FAIL;
+ }
+ if (access_type == MMU_INST_FETCH && !(pte & PTE_X)) {
+ /* Fetch access check failed */
+ return TRANSLATE_FAIL;
+ }
+
+ /* If necessary, set accessed and dirty bits. */
+ target_ulong updated_pte = pte | PTE_A |
(access_type == MMU_DATA_STORE ? PTE_D : 0);
- /* Page table updates need to be atomic with MTTCG enabled */
- if (updated_pte != pte) {
- if (!hade) {
- return TRANSLATE_FAIL;
- }
+ /* Page table updates need to be atomic with MTTCG enabled */
+ if (updated_pte != pte) {
+ if (!hade) {
+ return TRANSLATE_FAIL;
+ }
- /*
- * - if accessed or dirty bits need updating, and the PTE is
- * in RAM, then we do so atomically with a compare and swap.
- * - if the PTE is in IO space or ROM, then it can't be updated
- * and we return TRANSLATE_FAIL.
- * - if the PTE changed by the time we went to update it, then
- * it is no longer valid and we must re-walk the page table.
- */
- MemoryRegion *mr;
- hwaddr l = sizeof(target_ulong), addr1;
- mr = address_space_translate(cs->as, pte_addr, &addr1, &l,
- false, MEMTXATTRS_UNSPECIFIED);
- if (memory_region_is_ram(mr)) {
- target_ulong *pte_pa =
- qemu_map_ram_ptr(mr->ram_block, addr1);
+ /*
+ * - if accessed or dirty bits need updating, and the PTE is
+ * in RAM, then we do so atomically with a compare and swap.
+ * - if the PTE is in IO space or ROM, then it can't be updated
+ * and we return TRANSLATE_FAIL.
+ * - if the PTE changed by the time we went to update it, then
+ * it is no longer valid and we must re-walk the page table.
+ */
+ MemoryRegion *mr;
+ hwaddr l = sizeof(target_ulong), addr1;
+ mr = address_space_translate(cs->as, pte_addr, &addr1, &l,
+ false, MEMTXATTRS_UNSPECIFIED);
+ if (memory_region_is_ram(mr)) {
+ target_ulong *pte_pa = qemu_map_ram_ptr(mr->ram_block, addr1);
#if TCG_OVERSIZED_GUEST
- /*
- * MTTCG is not enabled on oversized TCG guests so
- * page table updates do not need to be atomic
- */
- *pte_pa = pte = updated_pte;
+ /*
+ * MTTCG is not enabled on oversized TCG guests so
+ * page table updates do not need to be atomic
+ */
+ *pte_pa = pte = updated_pte;
#else
- target_ulong old_pte =
- qatomic_cmpxchg(pte_pa, pte, updated_pte);
- if (old_pte != pte) {
- goto restart;
- } else {
- pte = updated_pte;
- }
+ target_ulong old_pte = qatomic_cmpxchg(pte_pa, pte, updated_pte);
+ if (old_pte != pte) {
+ goto restart;
+ }
+ pte = updated_pte;
#endif
- } else {
- /*
- * misconfigured PTE in ROM (AD bits are not preset) or
- * PTE is in IO space and can't be updated atomically
- */
- return TRANSLATE_FAIL;
- }
- }
-
+ } else {
/*
- * for superpage mappings, make a fake leaf PTE for the TLB's
- * benefit.
+ * Misconfigured PTE in ROM (AD bits are not preset) or
+ * PTE is in IO space and can't be updated atomically.
*/
- target_ulong vpn = addr >> PGSHIFT;
-
- if (riscv_cpu_cfg(env)->ext_svnapot && (pte & PTE_N)) {
- napot_bits = ctzl(ppn) + 1;
- if ((i != (levels - 1)) || (napot_bits != 4)) {
- return TRANSLATE_FAIL;
- }
- }
-
- napot_mask = (1 << napot_bits) - 1;
- *physical = (((ppn & ~napot_mask) | (vpn & napot_mask) |
- (vpn & (((target_ulong)1 << ptshift) - 1))
- ) << PGSHIFT) | (addr & ~TARGET_PAGE_MASK);
-
- /* set permissions on the TLB entry */
- if ((pte & PTE_R) || ((pte & PTE_X) && mxr)) {
- *prot |= PAGE_READ;
- }
- if (pte & PTE_X) {
- *prot |= PAGE_EXEC;
- }
- /*
- * add write permission on stores or if the page is already dirty,
- * so that we TLB miss on later writes to update the dirty bit
- */
- if ((pte & PTE_W) &&
- (access_type == MMU_DATA_STORE || (pte & PTE_D))) {
- *prot |= PAGE_WRITE;
- }
- return TRANSLATE_SUCCESS;
+ return TRANSLATE_FAIL;
}
}
- return TRANSLATE_FAIL;
+
+ /* For superpage mappings, make a fake leaf PTE for the TLB's benefit. */
+ target_ulong vpn = addr >> PGSHIFT;
+
+ if (riscv_cpu_cfg(env)->ext_svnapot && (pte & PTE_N)) {
+ napot_bits = ctzl(ppn) + 1;
+ if ((i != (levels - 1)) || (napot_bits != 4)) {
+ return TRANSLATE_FAIL;
+ }
+ }
+
+ napot_mask = (1 << napot_bits) - 1;
+ *physical = (((ppn & ~napot_mask) | (vpn & napot_mask) |
+ (vpn & (((target_ulong)1 << ptshift) - 1))
+ ) << PGSHIFT) | (addr & ~TARGET_PAGE_MASK);
+
+ /* set permissions on the TLB entry */
+ if ((pte & PTE_R) || ((pte & PTE_X) && mxr)) {
+ *prot |= PAGE_READ;
+ }
+ if (pte & PTE_X) {
+ *prot |= PAGE_EXEC;
+ }
+ /*
+ * Add write permission on stores or if the page is already dirty,
+ * so that we TLB miss on later writes to update the dirty bit.
+ */
+ if ((pte & PTE_W) && (access_type == MMU_DATA_STORE || (pte & PTE_D))) {
+ *prot |= PAGE_WRITE;
+ }
+ return TRANSLATE_SUCCESS;
}
static void raise_mmu_exception(CPURISCVState *env, target_ulong address,
--
2.34.1
next prev parent reply other threads:[~2023-04-12 11:46 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-12 11:43 [PATCH v7 00/25] target/riscv: MSTATUS_SUM + cleanups Richard Henderson
2023-04-12 11:43 ` [PATCH v7 01/25] target/riscv: Extract virt enabled state from tb flags Richard Henderson
2023-04-12 11:43 ` [PATCH v7 02/25] target/riscv: Add a general status enum for extensions Richard Henderson
2023-04-12 11:43 ` [PATCH v7 03/25] target/riscv: Encode the FS and VS on a normal way for tb flags Richard Henderson
2023-04-12 11:43 ` [PATCH v7 04/25] target/riscv: Remove mstatus_hs_{fs, vs} from tb_flags Richard Henderson
2023-04-12 11:43 ` [PATCH v7 05/25] target/riscv: Add a tb flags field for vstart Richard Henderson
2023-04-12 11:43 ` [PATCH v7 06/25] target/riscv: Separate priv from mmu_idx Richard Henderson
2023-04-12 11:43 ` [PATCH v7 07/25] target/riscv: Reduce overhead of MSTATUS_SUM change Richard Henderson
2023-04-12 11:43 ` [PATCH v7 08/25] accel/tcg: Add cpu_ld*_code_mmu Richard Henderson
2023-04-12 11:43 ` [PATCH v7 09/25] target/riscv: Use cpu_ld*_code_mmu for HLVX Richard Henderson
2023-04-12 11:43 ` [PATCH v7 10/25] target/riscv: Handle HLV, HSV via helpers Richard Henderson
2023-04-12 11:43 ` [PATCH v7 11/25] target/riscv: Rename MMU_HYP_ACCESS_BIT to MMU_2STAGE_BIT Richard Henderson
2023-04-12 11:43 ` [PATCH v7 12/25] target/riscv: Introduce mmuidx_sum Richard Henderson
2023-04-12 11:43 ` [PATCH v7 13/25] target/riscv: Introduce mmuidx_priv Richard Henderson
2023-04-12 11:43 ` [PATCH v7 14/25] target/riscv: Introduce mmuidx_2stage Richard Henderson
2023-04-12 11:43 ` [PATCH v7 15/25] target/riscv: Move hstatus.spvp check to check_access_hlsv Richard Henderson
2023-04-12 11:43 ` [PATCH v7 16/25] target/riscv: Set MMU_2STAGE_BIT in riscv_cpu_mmu_index Richard Henderson
2023-04-12 11:43 ` [PATCH v7 17/25] target/riscv: Check SUM in the correct register Richard Henderson
2023-04-12 11:43 ` [PATCH v7 18/25] target/riscv: Hoist second stage mode change to callers Richard Henderson
2023-04-12 11:43 ` [PATCH v7 19/25] target/riscv: Hoist pbmte and hade out of the level loop Richard Henderson
2023-04-12 11:43 ` Richard Henderson [this message]
2023-04-12 11:43 ` [PATCH v7 21/25] target/riscv: Suppress pte update with is_debug Richard Henderson
2023-04-12 11:43 ` [PATCH v7 22/25] target/riscv: Don't modify SUM " Richard Henderson
2023-04-12 11:43 ` [PATCH v7 23/25] target/riscv: Merge checks for reserved pte flags Richard Henderson
2023-04-12 11:43 ` [PATCH v7 24/25] target/riscv: Reorg access check in get_physical_address Richard Henderson
2023-04-12 11:43 ` [PATCH v7 25/25] target/riscv: Reorg sum " Richard Henderson
2023-04-17 2:11 ` [PATCH v7 00/25] target/riscv: MSTATUS_SUM + cleanups Alistair Francis
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