qemu-e2k/target-ppc/mmu-hash64.c
David Gibson e01b444523 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 <david@gibson.dropbear.id.au>
Signed-off-by: Alexander Graf <agraf@suse.de>
2013-03-22 15:28:52 +01:00

548 lines
16 KiB
C

/*
* PowerPC MMU, TLB, SLB and BAT emulation helpers for QEMU.
*
* Copyright (c) 2003-2007 Jocelyn Mayer
* Copyright (c) 2013 David Gibson, IBM Corporation
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this library; if not, see <http://www.gnu.org/licenses/>.
*/
#include "cpu.h"
#include "helper.h"
#include "sysemu/kvm.h"
#include "kvm_ppc.h"
#include "mmu-hash64.h"
//#define DEBUG_MMU
//#define DEBUG_SLB
#ifdef DEBUG_MMU
# define LOG_MMU(...) qemu_log(__VA_ARGS__)
# define LOG_MMU_STATE(env) log_cpu_state((env), 0)
#else
# define LOG_MMU(...) do { } while (0)
# define LOG_MMU_STATE(...) do { } while (0)
#endif
#ifdef DEBUG_SLB
# define LOG_SLB(...) qemu_log(__VA_ARGS__)
#else
# define LOG_SLB(...) do { } while (0)
#endif
struct mmu_ctx_hash64 {
hwaddr raddr; /* Real address */
int prot; /* Protection bits */
};
/*
* SLB handling
*/
static ppc_slb_t *slb_lookup(CPUPPCState *env, target_ulong eaddr)
{
uint64_t esid_256M, esid_1T;
int n;
LOG_SLB("%s: eaddr " TARGET_FMT_lx "\n", __func__, eaddr);
esid_256M = (eaddr & SEGMENT_MASK_256M) | SLB_ESID_V;
esid_1T = (eaddr & SEGMENT_MASK_1T) | SLB_ESID_V;
for (n = 0; n < env->slb_nr; n++) {
ppc_slb_t *slb = &env->slb[n];
LOG_SLB("%s: slot %d %016" PRIx64 " %016"
PRIx64 "\n", __func__, n, slb->esid, slb->vsid);
/* We check for 1T matches on all MMUs here - if the MMU
* doesn't have 1T segment support, we will have prevented 1T
* entries from being inserted in the slbmte code. */
if (((slb->esid == esid_256M) &&
((slb->vsid & SLB_VSID_B) == SLB_VSID_B_256M))
|| ((slb->esid == esid_1T) &&
((slb->vsid & SLB_VSID_B) == SLB_VSID_B_1T))) {
return slb;
}
}
return NULL;
}
void dump_slb(FILE *f, fprintf_function cpu_fprintf, CPUPPCState *env)
{
int i;
uint64_t slbe, slbv;
cpu_synchronize_state(env);
cpu_fprintf(f, "SLB\tESID\t\t\tVSID\n");
for (i = 0; i < env->slb_nr; i++) {
slbe = env->slb[i].esid;
slbv = env->slb[i].vsid;
if (slbe == 0 && slbv == 0) {
continue;
}
cpu_fprintf(f, "%d\t0x%016" PRIx64 "\t0x%016" PRIx64 "\n",
i, slbe, slbv);
}
}
void helper_slbia(CPUPPCState *env)
{
int n, do_invalidate;
do_invalidate = 0;
/* XXX: Warning: slbia never invalidates the first segment */
for (n = 1; n < env->slb_nr; n++) {
ppc_slb_t *slb = &env->slb[n];
if (slb->esid & SLB_ESID_V) {
slb->esid &= ~SLB_ESID_V;
/* XXX: given the fact that segment size is 256 MB or 1TB,
* and we still don't have a tlb_flush_mask(env, n, mask)
* in QEMU, we just invalidate all TLBs
*/
do_invalidate = 1;
}
}
if (do_invalidate) {
tlb_flush(env, 1);
}
}
void helper_slbie(CPUPPCState *env, target_ulong addr)
{
ppc_slb_t *slb;
slb = slb_lookup(env, addr);
if (!slb) {
return;
}
if (slb->esid & SLB_ESID_V) {
slb->esid &= ~SLB_ESID_V;
/* XXX: given the fact that segment size is 256 MB or 1TB,
* and we still don't have a tlb_flush_mask(env, n, mask)
* in QEMU, we just invalidate all TLBs
*/
tlb_flush(env, 1);
}
}
int ppc_store_slb(CPUPPCState *env, target_ulong rb, target_ulong rs)
{
int slot = rb & 0xfff;
ppc_slb_t *slb = &env->slb[slot];
if (rb & (0x1000 - env->slb_nr)) {
return -1; /* Reserved bits set or slot too high */
}
if (rs & (SLB_VSID_B & ~SLB_VSID_B_1T)) {
return -1; /* Bad segment size */
}
if ((rs & SLB_VSID_B) && !(env->mmu_model & POWERPC_MMU_1TSEG)) {
return -1; /* 1T segment on MMU that doesn't support it */
}
/* Mask out the slot number as we store the entry */
slb->esid = rb & (SLB_ESID_ESID | SLB_ESID_V);
slb->vsid = rs;
LOG_SLB("%s: %d " TARGET_FMT_lx " - " TARGET_FMT_lx " => %016" PRIx64
" %016" PRIx64 "\n", __func__, slot, rb, rs,
slb->esid, slb->vsid);
return 0;
}
static int ppc_load_slb_esid(CPUPPCState *env, target_ulong rb,
target_ulong *rt)
{
int slot = rb & 0xfff;
ppc_slb_t *slb = &env->slb[slot];
if (slot >= env->slb_nr) {
return -1;
}
*rt = slb->esid;
return 0;
}
static int ppc_load_slb_vsid(CPUPPCState *env, target_ulong rb,
target_ulong *rt)
{
int slot = rb & 0xfff;
ppc_slb_t *slb = &env->slb[slot];
if (slot >= env->slb_nr) {
return -1;
}
*rt = slb->vsid;
return 0;
}
void helper_store_slb(CPUPPCState *env, target_ulong rb, target_ulong rs)
{
if (ppc_store_slb(env, rb, rs) < 0) {
helper_raise_exception_err(env, POWERPC_EXCP_PROGRAM,
POWERPC_EXCP_INVAL);
}
}
target_ulong helper_load_slb_esid(CPUPPCState *env, target_ulong rb)
{
target_ulong rt = 0;
if (ppc_load_slb_esid(env, rb, &rt) < 0) {
helper_raise_exception_err(env, POWERPC_EXCP_PROGRAM,
POWERPC_EXCP_INVAL);
}
return rt;
}
target_ulong helper_load_slb_vsid(CPUPPCState *env, target_ulong rb)
{
target_ulong rt = 0;
if (ppc_load_slb_vsid(env, rb, &rt) < 0) {
helper_raise_exception_err(env, POWERPC_EXCP_PROGRAM,
POWERPC_EXCP_INVAL);
}
return rt;
}
/*
* 64-bit hash table MMU handling
*/
static int ppc_hash64_pte_prot(CPUPPCState *env,
ppc_slb_t *slb, ppc_hash_pte64_t pte)
{
unsigned pp, key;
/* Some pp bit combinations have undefined behaviour, so default
* to no access in those cases */
int prot = 0;
key = !!(msr_pr ? (slb->vsid & SLB_VSID_KP)
: (slb->vsid & SLB_VSID_KS));
pp = (pte.pte1 & HPTE64_R_PP) | ((pte.pte1 & HPTE64_R_PP0) >> 61);
if (key == 0) {
switch (pp) {
case 0x0:
case 0x1:
case 0x2:
prot = PAGE_READ | PAGE_WRITE;
break;
case 0x3:
case 0x6:
prot = PAGE_READ;
break;
}
} else {
switch (pp) {
case 0x0:
case 0x6:
prot = 0;
break;
case 0x1:
case 0x3:
prot = PAGE_READ;
break;
case 0x2:
prot = PAGE_READ | PAGE_WRITE;
break;
}
}
/* No execute if either noexec or guarded bits set */
if (!(pte.pte1 & HPTE64_R_N) || (pte.pte1 & HPTE64_R_G)) {
prot |= PAGE_EXEC;
}
return prot;
}
static int ppc_hash64_pte_update_flags(struct mmu_ctx_hash64 *ctx,
uint64_t *pte1p, int ret, int rw)
{
int store = 0;
/* Update page flags */
if (!(*pte1p & HPTE64_R_R)) {
/* Update accessed flag */
*pte1p |= HPTE64_R_R;
store = 1;
}
if (!(*pte1p & HPTE64_R_C)) {
if (rw == 1 && ret == 0) {
/* Update changed flag */
*pte1p |= HPTE64_R_C;
store = 1;
} else {
/* Force page fault for first write access */
ctx->prot &= ~PAGE_WRITE;
}
}
return store;
}
static hwaddr ppc_hash64_pteg_search(CPUPPCState *env, hwaddr pteg_off,
bool secondary, target_ulong ptem,
ppc_hash_pte64_t *pte)
{
hwaddr pte_offset = pteg_off;
target_ulong pte0, pte1;
int i;
for (i = 0; i < HPTES_PER_GROUP; i++) {
pte0 = ppc_hash64_load_hpte0(env, pte_offset);
pte1 = ppc_hash64_load_hpte1(env, pte_offset);
if ((pte0 & HPTE64_V_VALID)
&& (secondary == !!(pte0 & HPTE64_V_SECONDARY))
&& HPTE64_V_COMPARE(pte0, ptem)) {
pte->pte0 = pte0;
pte->pte1 = pte1;
return pte_offset;
}
pte_offset += HASH_PTE_SIZE_64;
}
return -1;
}
static hwaddr ppc_hash64_htab_lookup(CPUPPCState *env,
ppc_slb_t *slb, target_ulong eaddr,
ppc_hash_pte64_t *pte)
{
hwaddr pteg_off, pte_offset;
hwaddr hash;
uint64_t vsid, epnshift, epnmask, epn, ptem;
/* Page size according to the SLB, which we use to generate the
* EPN for hash table lookup.. When we implement more recent MMU
* extensions this might be different from the actual page size
* encoded in the PTE */
epnshift = (slb->vsid & SLB_VSID_L)
? TARGET_PAGE_BITS_16M : TARGET_PAGE_BITS;
epnmask = ~((1ULL << epnshift) - 1);
if (slb->vsid & SLB_VSID_B) {
/* 1TB segment */
vsid = (slb->vsid & SLB_VSID_VSID) >> SLB_VSID_SHIFT_1T;
epn = (eaddr & ~SEGMENT_MASK_1T) & epnmask;
hash = vsid ^ (vsid << 25) ^ (epn >> epnshift);
} else {
/* 256M segment */
vsid = (slb->vsid & SLB_VSID_VSID) >> SLB_VSID_SHIFT;
epn = (eaddr & ~SEGMENT_MASK_256M) & epnmask;
hash = vsid ^ (epn >> epnshift);
}
ptem = (slb->vsid & SLB_VSID_PTEM) | ((epn >> 16) & HPTE64_V_AVPN);
/* Page address translation */
LOG_MMU("htab_base " TARGET_FMT_plx " htab_mask " TARGET_FMT_plx
" hash " TARGET_FMT_plx "\n",
env->htab_base, env->htab_mask, hash);
/* Primary PTEG lookup */
LOG_MMU("0 htab=" TARGET_FMT_plx "/" TARGET_FMT_plx
" vsid=" TARGET_FMT_lx " ptem=" TARGET_FMT_lx
" hash=" TARGET_FMT_plx "\n",
env->htab_base, env->htab_mask, vsid, ptem, hash);
pteg_off = (hash * HASH_PTEG_SIZE_64) & env->htab_mask;
pte_offset = ppc_hash64_pteg_search(env, pteg_off, 0, ptem, pte);
if (pte_offset == -1) {
/* Secondary PTEG lookup */
LOG_MMU("1 htab=" TARGET_FMT_plx "/" TARGET_FMT_plx
" vsid=" TARGET_FMT_lx " api=" TARGET_FMT_lx
" hash=" TARGET_FMT_plx "\n", env->htab_base,
env->htab_mask, vsid, ptem, ~hash);
pteg_off = (~hash * HASH_PTEG_SIZE_64) & env->htab_mask;
pte_offset = ppc_hash64_pteg_search(env, pteg_off, 1, ptem, pte);
}
return pte_offset;
}
static int ppc_hash64_translate(CPUPPCState *env, struct mmu_ctx_hash64 *ctx,
target_ulong eaddr, int rwx)
{
ppc_slb_t *slb;
hwaddr pte_offset;
ppc_hash_pte64_t pte;
int target_page_bits;
const int need_prot[] = {PAGE_READ, PAGE_WRITE, PAGE_EXEC};
assert((rwx == 0) || (rwx == 1) || (rwx == 2));
/* 1. Handle real mode accesses */
if (((rwx == 2) && (msr_ir == 0)) || ((rwx != 2) && (msr_dr == 0))) {
/* Translation is off */
/* In real mode the top 4 effective address bits are ignored */
ctx->raddr = eaddr & 0x0FFFFFFFFFFFFFFFULL;
ctx->prot = PAGE_READ | PAGE_EXEC | PAGE_WRITE;
return 0;
}
/* 2. Translation is on, so look up the SLB */
slb = slb_lookup(env, eaddr);
if (!slb) {
return -5;
}
/* 3. Check for segment level no-execute violation */
if ((rwx == 2) && (slb->vsid & SLB_VSID_N)) {
return -3;
}
/* 4. Locate the PTE in the hash table */
pte_offset = ppc_hash64_htab_lookup(env, slb, eaddr, &pte);
if (pte_offset == -1) {
return -1;
}
LOG_MMU("found PTE at offset %08" HWADDR_PRIx "\n", pte_offset);
/* 5. Check access permissions */
ctx->prot = ppc_hash64_pte_prot(env, slb, pte);
if ((need_prot[rwx] & ~ctx->prot) != 0) {
/* Access right violation */
LOG_MMU("PTE access rejected\n");
return -2;
}
LOG_MMU("PTE access granted !\n");
/* 6. Update PTE referenced and changed bits if necessary */
if (ppc_hash64_pte_update_flags(ctx, &pte.pte1, 0, rwx) == 1) {
ppc_hash64_store_hpte1(env, pte_offset, pte.pte1);
}
/* Keep the matching PTE informations */
ctx->raddr = pte.pte1;
/* We have a TLB that saves 4K pages, so let's
* split a huge page to 4k chunks */
target_page_bits = (slb->vsid & SLB_VSID_L)
? TARGET_PAGE_BITS_16M : TARGET_PAGE_BITS;
if (target_page_bits != TARGET_PAGE_BITS) {
ctx->raddr |= (eaddr & ((1 << target_page_bits) - 1))
& TARGET_PAGE_MASK;
}
return 0;
}
hwaddr ppc_hash64_get_phys_page_debug(CPUPPCState *env, target_ulong addr)
{
struct mmu_ctx_hash64 ctx;
if (unlikely(ppc_hash64_translate(env, &ctx, addr, 0) != 0)) {
return -1;
}
return ctx.raddr & TARGET_PAGE_MASK;
}
int ppc_hash64_handle_mmu_fault(CPUPPCState *env, target_ulong address, int rwx,
int mmu_idx)
{
struct mmu_ctx_hash64 ctx;
int ret = 0;
ret = ppc_hash64_translate(env, &ctx, address, rwx);
if (ret == 0) {
tlb_set_page(env, address & TARGET_PAGE_MASK,
ctx.raddr & TARGET_PAGE_MASK, ctx.prot,
mmu_idx, TARGET_PAGE_SIZE);
ret = 0;
} else if (ret < 0) {
LOG_MMU_STATE(env);
if (rwx == 2) {
switch (ret) {
case -1:
env->exception_index = POWERPC_EXCP_ISI;
env->error_code = 0x40000000;
break;
case -2:
/* Access rights violation */
env->exception_index = POWERPC_EXCP_ISI;
env->error_code = 0x08000000;
break;
case -3:
/* No execute protection violation */
env->exception_index = POWERPC_EXCP_ISI;
env->error_code = 0x10000000;
break;
case -5:
/* No match in segment table */
env->exception_index = POWERPC_EXCP_ISEG;
env->error_code = 0;
break;
}
} else {
switch (ret) {
case -1:
/* No matches in page tables or TLB */
env->exception_index = POWERPC_EXCP_DSI;
env->error_code = 0;
env->spr[SPR_DAR] = address;
if (rwx == 1) {
env->spr[SPR_DSISR] = 0x42000000;
} else {
env->spr[SPR_DSISR] = 0x40000000;
}
break;
case -2:
/* Access rights violation */
env->exception_index = POWERPC_EXCP_DSI;
env->error_code = 0;
env->spr[SPR_DAR] = address;
if (rwx == 1) {
env->spr[SPR_DSISR] = 0x0A000000;
} else {
env->spr[SPR_DSISR] = 0x08000000;
}
break;
case -5:
/* No match in segment table */
env->exception_index = POWERPC_EXCP_DSEG;
env->error_code = 0;
env->spr[SPR_DAR] = address;
break;
}
}
#if 0
printf("%s: set exception to %d %02x\n", __func__,
env->exception, env->error_code);
#endif
ret = 1;
}
return ret;
}