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target-ppc: Disentangle hash mmu helper functions

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The newly separated paths for hash mmus rely on several helper functions
which are still shared with 32-bit hash mmus: pp_check(), check_prot() and
pte_update_flags().  While these don't have ugly ifdefs on the mmu type,
they're not very well thought out, so sharing them impedes cleaning up the
hash mmu paths.  For now, put near-duplicate versions into mmu-hash64.c and
mmu-hash32.c, leaving the old version in mmu_helper.c for 6xx software
loaded tlb implementations.  The hash 32 and software loaded
implementations are simplfied slightly, using the fact that no 32-bit CPUs
implement the 3rd page protection bit.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
This commit is contained in:
David Gibson 2013-03-12 00:31:14 +00:00 • committed by Alexander Graf
parent f2ad6be83b
commit 496272a701
4 changed files with 193 additions and 16 deletions
Download patch file Download diff file Expand all files Collapse all files

96
target-ppc/mmu-hash32.c
View file

@ -37,6 +37,71 @@
#define PTE_PTEM_MASK 0x7FFFFFBF
#define PTE_CHECK_MASK (TARGET_PAGE_MASK | 0x7B)
static int ppc_hash32_pp_check(int key, int pp, int nx)
{
int access;
/* Compute access rights */
access = 0;
if (key == 0) {
switch (pp) {
case 0x0:
case 0x1:
case 0x2:
access |= PAGE_WRITE;
/* No break here */
case 0x3:
access |= PAGE_READ;
break;
}
} else {
switch (pp) {
case 0x0:
access = 0;
break;
case 0x1:
case 0x3:
access = PAGE_READ;
break;
case 0x2:
access = PAGE_READ | PAGE_WRITE;
break;
}
}
if (nx == 0) {
access |= PAGE_EXEC;
}
return access;
}
static int ppc_hash32_check_prot(int prot, int rw, int access_type)
{
int ret;
if (access_type == ACCESS_CODE) {
if (prot & PAGE_EXEC) {
ret = 0;
} else {
ret = -2;
}
} else if (rw) {
if (prot & PAGE_WRITE) {
ret = 0;
} else {
ret = -2;
}
} else {
if (prot & PAGE_READ) {
ret = 0;
} else {
ret = -2;
}
}
return ret;
}
static inline int pte_is_valid_hash32(target_ulong pte0)
{
return pte0 & 0x80000000 ? 1 : 0;
@ -66,11 +131,11 @@ static int pte_check_hash32(mmu_ctx_t *ctx, target_ulong pte0,
}
}
/* Compute access rights */
access = pp_check(ctx->key, pp, ctx->nx);
access = ppc_hash32_pp_check(ctx->key, pp, ctx->nx);
/* Keep the matching PTE informations */
ctx->raddr = pte1;
ctx->prot = access;
ret = check_prot(ctx->prot, rw, type);
ret = ppc_hash32_check_prot(ctx->prot, rw, type);
if (ret == 0) {
/* Access granted */
LOG_MMU("PTE access granted !\n");
@ -84,6 +149,31 @@ static int pte_check_hash32(mmu_ctx_t *ctx, target_ulong pte0,
return ret;
}
static int ppc_hash32_pte_update_flags(mmu_ctx_t *ctx, target_ulong *pte1p,
int ret, int rw)
{
int store = 0;
/* Update page flags */
if (!(*pte1p & 0x00000100)) {
/* Update accessed flag */
*pte1p |= 0x00000100;
store = 1;
}
if (!(*pte1p & 0x00000080)) {
if (rw == 1 && ret == 0) {
/* Update changed flag */
*pte1p |= 0x00000080;
store = 1;
} else {
/* Force page fault for first write access */
ctx->prot &= ~PAGE_WRITE;
}
}
return store;
}
/* PTE table lookup */
static int find_pte32(CPUPPCState *env, mmu_ctx_t *ctx, int h,
int rw, int type, int target_page_bits)
@ -138,7 +228,7 @@ static int find_pte32(CPUPPCState *env, mmu_ctx_t *ctx, int h,
ctx->raddr, ctx->prot, ret);
/* Update page flags */
pte1 = ctx->raddr;
if (pte_update_flags(ctx, &pte1, ret, rw) == 1) {
if (ppc_hash32_pte_update_flags(ctx, &pte1, ret, rw) == 1) {
if (env->external_htab) {
stl_p(env->external_htab + pteg_off + (good * 8) + 4,
pte1);