From e01b444523e2b0c663b42b3e8f44ef48a6153051 Mon Sep 17 00:00:00 2001 From: David Gibson Date: Tue, 12 Mar 2013 00:31:40 +0000 Subject: mmu-hash*: Clean up permission checking Currently checking of PTE permission bits is split messily amongst ppc_hash{32,64}_pp_check(), ppc_hash{32,64}_check_prot() and their callers. This patch cleans this up to have the new function ppc_hash{32,64}_pte_prot() compute the page permissions from the SLBE (for 64-bit) or segment register (32-bit) and the pte. A greatly simplified version of the actual permissions check is then open coded in the callers. The 32-bit version of ppc_hash32_pte_prot() is implemented in terms of ppc_hash32_pp_prot(), a renamed and slightly cleaned up version of the old ppc_hash32_pp_check(), which is also used for checking BAT permissions on the 601. Signed-off-by: David Gibson Signed-off-by: Alexander Graf --- target-ppc/mmu-hash32.c | 95 +++++++++++++++++++++---------------------------- 1 file changed, 40 insertions(+), 55 deletions(-) (limited to 'target-ppc/mmu-hash32.c') diff --git a/target-ppc/mmu-hash32.c b/target-ppc/mmu-hash32.c index 2b88b9ff3a..6581d0f425 100644 --- a/target-ppc/mmu-hash32.c +++ b/target-ppc/mmu-hash32.c @@ -47,69 +47,60 @@ struct mmu_ctx_hash32 { int key; /* Access key */ }; -static int ppc_hash32_pp_check(int key, int pp, int nx) +static int ppc_hash32_pp_prot(int key, int pp, int nx) { - int access; + int prot; - /* Compute access rights */ - access = 0; if (key == 0) { switch (pp) { case 0x0: case 0x1: case 0x2: - access |= PAGE_WRITE; - /* No break here */ + prot = PAGE_READ | PAGE_WRITE; + break; + case 0x3: - access |= PAGE_READ; + prot = PAGE_READ; break; + + default: + abort(); } } else { switch (pp) { case 0x0: - access = 0; + prot = 0; break; + case 0x1: case 0x3: - access = PAGE_READ; + prot = PAGE_READ; break; + case 0x2: - access = PAGE_READ | PAGE_WRITE; + prot = PAGE_READ | PAGE_WRITE; break; + + default: + abort(); } } if (nx == 0) { - access |= PAGE_EXEC; + prot |= PAGE_EXEC; } - return access; + return prot; } -static int ppc_hash32_check_prot(int prot, int rwx) +static int ppc_hash32_pte_prot(CPUPPCState *env, + target_ulong sr, ppc_hash_pte32_t pte) { - int ret; + unsigned pp, key; - if (rwx == 2) { - if (prot & PAGE_EXEC) { - ret = 0; - } else { - ret = -2; - } - } else if (rwx) { - if (prot & PAGE_WRITE) { - ret = 0; - } else { - ret = -2; - } - } else { - if (prot & PAGE_READ) { - ret = 0; - } else { - ret = -2; - } - } + key = !!(msr_pr ? (sr & SR32_KP) : (sr & SR32_KS)); + pp = pte.pte1 & HPTE32_R_PP; - return ret; + return ppc_hash32_pp_prot(key, pp, !!(sr & SR32_NX)); } static target_ulong hash32_bat_size(CPUPPCState *env, @@ -160,7 +151,7 @@ static int hash32_bat_601_prot(CPUPPCState *env, } else { key = !!(batu & BATU32_601_KP); } - return ppc_hash32_pp_check(key, pp, 0); + return ppc_hash32_pp_prot(key, pp, 0); } static hwaddr ppc_hash32_bat_lookup(CPUPPCState *env, target_ulong ea, int rwx, @@ -380,11 +371,10 @@ static hwaddr ppc_hash32_htab_lookup(CPUPPCState *env, static int ppc_hash32_translate(CPUPPCState *env, struct mmu_ctx_hash32 *ctx, target_ulong eaddr, int rwx) { - int ret; target_ulong sr; - bool nx; hwaddr pte_offset; ppc_hash_pte32_t pte; + const int need_prot[] = {PAGE_READ, PAGE_WRITE, PAGE_EXEC}; assert((rwx == 0) || (rwx == 1) || (rwx == 2)); @@ -400,7 +390,10 @@ static int ppc_hash32_translate(CPUPPCState *env, struct mmu_ctx_hash32 *ctx, if (env->nb_BATs != 0) { ctx->raddr = ppc_hash32_bat_lookup(env, eaddr, rwx, &ctx->prot); if (ctx->raddr != -1) { - return ppc_hash32_check_prot(ctx->prot, rwx); + if (need_prot[rwx] & ~ctx->prot) { + return -2; + } + return 0; } } @@ -414,8 +407,7 @@ static int ppc_hash32_translate(CPUPPCState *env, struct mmu_ctx_hash32 *ctx, } /* 5. Check for segment level no-execute violation */ - nx = !!(sr & SR32_NX); - if ((rwx == 2) && nx) { + if ((rwx == 2) && (sr & SR32_NX)) { return -3; } @@ -427,34 +419,27 @@ static int ppc_hash32_translate(CPUPPCState *env, struct mmu_ctx_hash32 *ctx, LOG_MMU("found PTE at offset %08" HWADDR_PRIx "\n", pte_offset); /* 7. Check access permissions */ - ctx->key = (((sr & SR32_KP) && (msr_pr != 0)) || - ((sr & SR32_KS) && (msr_pr == 0))) ? 1 : 0; - - int access, pp; - pp = pte.pte1 & HPTE32_R_PP; - /* Compute access rights */ - access = ppc_hash32_pp_check(ctx->key, pp, nx); - /* Keep the matching PTE informations */ - ctx->raddr = pte.pte1; - ctx->prot = access; - ret = ppc_hash32_check_prot(ctx->prot, rwx); + ctx->prot = ppc_hash32_pte_prot(env, sr, pte); - if (ret) { + if (need_prot[rwx] & ~ctx->prot) { /* Access right violation */ LOG_MMU("PTE access rejected\n"); - return ret; + return -2; } LOG_MMU("PTE access granted !\n"); /* 8. Update PTE referenced and changed bits if necessary */ - if (ppc_hash32_pte_update_flags(ctx, &pte.pte1, ret, rwx) == 1) { + if (ppc_hash32_pte_update_flags(ctx, &pte.pte1, 0, rwx) == 1) { ppc_hash32_store_hpte1(env, pte_offset, pte.pte1); } - return ret; + /* Keep the matching PTE informations */ + ctx->raddr = pte.pte1; + + return 0; } hwaddr ppc_hash32_get_phys_page_debug(CPUPPCState *env, target_ulong addr) -- cgit v1.2.1