From 59688aa02340ed51113e5574bf4c3ced3b73220a Mon Sep 17 00:00:00 2001 From: Richard Henderson Date: Wed, 12 Apr 2023 13:43:28 +0200 Subject: [PATCH] target/riscv: Move leaf pte processing out of level loop Move the code that never loops outside of the loop. Unchain the if-return-else statements. Signed-off-by: Richard Henderson Reviewed-by: Alistair Francis Reviewed-by: Weiwei Li Tested-by: Daniel Henrique Barboza Message-Id: <20230325105429.1142530-21-richard.henderson@linaro.org> Message-Id: <20230412114333.118895-21-richard.henderson@linaro.org> Signed-off-by: Alistair Francis --- target/riscv/cpu_helper.c | 234 ++++++++++++++++++++------------------ 1 file changed, 123 insertions(+), 111 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)) { - 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 */ + } + 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 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; - } -#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; - } + target_ulong old_pte = qatomic_cmpxchg(pte_pa, pte, updated_pte); + if (old_pte != pte) { + goto restart; } - + pte = updated_pte; +#endif + } 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; - } - } + 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); + /* For superpage mappings, make a fake leaf PTE for the TLB's benefit. */ + target_ulong vpn = addr >> PGSHIFT; - /* 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; + 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; } } - 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, -- 2.39.2