qemu/accel/tcg/softmmu_template.h
Peter Maydell 55df6fcf54 tcg: Support MMU protection regions smaller than TARGET_PAGE_SIZE
Add support for MMU protection regions that are smaller than
TARGET_PAGE_SIZE. We do this by marking the TLB entry for those
pages with a flag TLB_RECHECK. This flag causes us to always
take the slow-path for accesses. In the slow path we can then
special case them to always call tlb_fill() again, so we have
the correct information for the exact address being accessed.

This change allows us to handle reading and writing from small
regions; we cannot deal with execution from the small region.

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-id: 20180620130619.11362-2-peter.maydell@linaro.org
2018-06-26 17:50:41 +01:00

444 lines
16 KiB
C

/*
* Software MMU support
*
* Generate helpers used by TCG for qemu_ld/st ops and code load
* functions.
*
* Included from target op helpers and exec.c.
*
* Copyright (c) 2003 Fabrice Bellard
*
* 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/>.
*/
#if DATA_SIZE == 8
#define SUFFIX q
#define LSUFFIX q
#define SDATA_TYPE int64_t
#define DATA_TYPE uint64_t
#elif DATA_SIZE == 4
#define SUFFIX l
#define LSUFFIX l
#define SDATA_TYPE int32_t
#define DATA_TYPE uint32_t
#elif DATA_SIZE == 2
#define SUFFIX w
#define LSUFFIX uw
#define SDATA_TYPE int16_t
#define DATA_TYPE uint16_t
#elif DATA_SIZE == 1
#define SUFFIX b
#define LSUFFIX ub
#define SDATA_TYPE int8_t
#define DATA_TYPE uint8_t
#else
#error unsupported data size
#endif
/* For the benefit of TCG generated code, we want to avoid the complication
of ABI-specific return type promotion and always return a value extended
to the register size of the host. This is tcg_target_long, except in the
case of a 32-bit host and 64-bit data, and for that we always have
uint64_t. Don't bother with this widened value for SOFTMMU_CODE_ACCESS. */
#if defined(SOFTMMU_CODE_ACCESS) || DATA_SIZE == 8
# define WORD_TYPE DATA_TYPE
# define USUFFIX SUFFIX
#else
# define WORD_TYPE tcg_target_ulong
# define USUFFIX glue(u, SUFFIX)
# define SSUFFIX glue(s, SUFFIX)
#endif
#ifdef SOFTMMU_CODE_ACCESS
#define READ_ACCESS_TYPE MMU_INST_FETCH
#define ADDR_READ addr_code
#else
#define READ_ACCESS_TYPE MMU_DATA_LOAD
#define ADDR_READ addr_read
#endif
#if DATA_SIZE == 8
# define BSWAP(X) bswap64(X)
#elif DATA_SIZE == 4
# define BSWAP(X) bswap32(X)
#elif DATA_SIZE == 2
# define BSWAP(X) bswap16(X)
#else
# define BSWAP(X) (X)
#endif
#if DATA_SIZE == 1
# define helper_le_ld_name glue(glue(helper_ret_ld, USUFFIX), MMUSUFFIX)
# define helper_be_ld_name helper_le_ld_name
# define helper_le_lds_name glue(glue(helper_ret_ld, SSUFFIX), MMUSUFFIX)
# define helper_be_lds_name helper_le_lds_name
# define helper_le_st_name glue(glue(helper_ret_st, SUFFIX), MMUSUFFIX)
# define helper_be_st_name helper_le_st_name
#else
# define helper_le_ld_name glue(glue(helper_le_ld, USUFFIX), MMUSUFFIX)
# define helper_be_ld_name glue(glue(helper_be_ld, USUFFIX), MMUSUFFIX)
# define helper_le_lds_name glue(glue(helper_le_ld, SSUFFIX), MMUSUFFIX)
# define helper_be_lds_name glue(glue(helper_be_ld, SSUFFIX), MMUSUFFIX)
# define helper_le_st_name glue(glue(helper_le_st, SUFFIX), MMUSUFFIX)
# define helper_be_st_name glue(glue(helper_be_st, SUFFIX), MMUSUFFIX)
#endif
#ifndef SOFTMMU_CODE_ACCESS
static inline DATA_TYPE glue(io_read, SUFFIX)(CPUArchState *env,
size_t mmu_idx, size_t index,
target_ulong addr,
uintptr_t retaddr,
bool recheck)
{
CPUIOTLBEntry *iotlbentry = &env->iotlb[mmu_idx][index];
return io_readx(env, iotlbentry, mmu_idx, addr, retaddr, recheck,
DATA_SIZE);
}
#endif
WORD_TYPE helper_le_ld_name(CPUArchState *env, target_ulong addr,
TCGMemOpIdx oi, uintptr_t retaddr)
{
unsigned mmu_idx = get_mmuidx(oi);
int index = (addr >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1);
target_ulong tlb_addr = env->tlb_table[mmu_idx][index].ADDR_READ;
unsigned a_bits = get_alignment_bits(get_memop(oi));
uintptr_t haddr;
DATA_TYPE res;
if (addr & ((1 << a_bits) - 1)) {
cpu_unaligned_access(ENV_GET_CPU(env), addr, READ_ACCESS_TYPE,
mmu_idx, retaddr);
}
/* If the TLB entry is for a different page, reload and try again. */
if ((addr & TARGET_PAGE_MASK)
!= (tlb_addr & (TARGET_PAGE_MASK | TLB_INVALID_MASK))) {
if (!VICTIM_TLB_HIT(ADDR_READ, addr)) {
tlb_fill(ENV_GET_CPU(env), addr, DATA_SIZE, READ_ACCESS_TYPE,
mmu_idx, retaddr);
}
tlb_addr = env->tlb_table[mmu_idx][index].ADDR_READ;
}
/* Handle an IO access. */
if (unlikely(tlb_addr & ~TARGET_PAGE_MASK)) {
if ((addr & (DATA_SIZE - 1)) != 0) {
goto do_unaligned_access;
}
/* ??? Note that the io helpers always read data in the target
byte ordering. We should push the LE/BE request down into io. */
res = glue(io_read, SUFFIX)(env, mmu_idx, index, addr, retaddr,
tlb_addr & TLB_RECHECK);
res = TGT_LE(res);
return res;
}
/* Handle slow unaligned access (it spans two pages or IO). */
if (DATA_SIZE > 1
&& unlikely((addr & ~TARGET_PAGE_MASK) + DATA_SIZE - 1
>= TARGET_PAGE_SIZE)) {
target_ulong addr1, addr2;
DATA_TYPE res1, res2;
unsigned shift;
do_unaligned_access:
addr1 = addr & ~(DATA_SIZE - 1);
addr2 = addr1 + DATA_SIZE;
res1 = helper_le_ld_name(env, addr1, oi, retaddr);
res2 = helper_le_ld_name(env, addr2, oi, retaddr);
shift = (addr & (DATA_SIZE - 1)) * 8;
/* Little-endian combine. */
res = (res1 >> shift) | (res2 << ((DATA_SIZE * 8) - shift));
return res;
}
haddr = addr + env->tlb_table[mmu_idx][index].addend;
#if DATA_SIZE == 1
res = glue(glue(ld, LSUFFIX), _p)((uint8_t *)haddr);
#else
res = glue(glue(ld, LSUFFIX), _le_p)((uint8_t *)haddr);
#endif
return res;
}
#if DATA_SIZE > 1
WORD_TYPE helper_be_ld_name(CPUArchState *env, target_ulong addr,
TCGMemOpIdx oi, uintptr_t retaddr)
{
unsigned mmu_idx = get_mmuidx(oi);
int index = (addr >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1);
target_ulong tlb_addr = env->tlb_table[mmu_idx][index].ADDR_READ;
unsigned a_bits = get_alignment_bits(get_memop(oi));
uintptr_t haddr;
DATA_TYPE res;
if (addr & ((1 << a_bits) - 1)) {
cpu_unaligned_access(ENV_GET_CPU(env), addr, READ_ACCESS_TYPE,
mmu_idx, retaddr);
}
/* If the TLB entry is for a different page, reload and try again. */
if ((addr & TARGET_PAGE_MASK)
!= (tlb_addr & (TARGET_PAGE_MASK | TLB_INVALID_MASK))) {
if (!VICTIM_TLB_HIT(ADDR_READ, addr)) {
tlb_fill(ENV_GET_CPU(env), addr, DATA_SIZE, READ_ACCESS_TYPE,
mmu_idx, retaddr);
}
tlb_addr = env->tlb_table[mmu_idx][index].ADDR_READ;
}
/* Handle an IO access. */
if (unlikely(tlb_addr & ~TARGET_PAGE_MASK)) {
if ((addr & (DATA_SIZE - 1)) != 0) {
goto do_unaligned_access;
}
/* ??? Note that the io helpers always read data in the target
byte ordering. We should push the LE/BE request down into io. */
res = glue(io_read, SUFFIX)(env, mmu_idx, index, addr, retaddr,
tlb_addr & TLB_RECHECK);
res = TGT_BE(res);
return res;
}
/* Handle slow unaligned access (it spans two pages or IO). */
if (DATA_SIZE > 1
&& unlikely((addr & ~TARGET_PAGE_MASK) + DATA_SIZE - 1
>= TARGET_PAGE_SIZE)) {
target_ulong addr1, addr2;
DATA_TYPE res1, res2;
unsigned shift;
do_unaligned_access:
addr1 = addr & ~(DATA_SIZE - 1);
addr2 = addr1 + DATA_SIZE;
res1 = helper_be_ld_name(env, addr1, oi, retaddr);
res2 = helper_be_ld_name(env, addr2, oi, retaddr);
shift = (addr & (DATA_SIZE - 1)) * 8;
/* Big-endian combine. */
res = (res1 << shift) | (res2 >> ((DATA_SIZE * 8) - shift));
return res;
}
haddr = addr + env->tlb_table[mmu_idx][index].addend;
res = glue(glue(ld, LSUFFIX), _be_p)((uint8_t *)haddr);
return res;
}
#endif /* DATA_SIZE > 1 */
#ifndef SOFTMMU_CODE_ACCESS
/* Provide signed versions of the load routines as well. We can of course
avoid this for 64-bit data, or for 32-bit data on 32-bit host. */
#if DATA_SIZE * 8 < TCG_TARGET_REG_BITS
WORD_TYPE helper_le_lds_name(CPUArchState *env, target_ulong addr,
TCGMemOpIdx oi, uintptr_t retaddr)
{
return (SDATA_TYPE)helper_le_ld_name(env, addr, oi, retaddr);
}
# if DATA_SIZE > 1
WORD_TYPE helper_be_lds_name(CPUArchState *env, target_ulong addr,
TCGMemOpIdx oi, uintptr_t retaddr)
{
return (SDATA_TYPE)helper_be_ld_name(env, addr, oi, retaddr);
}
# endif
#endif
static inline void glue(io_write, SUFFIX)(CPUArchState *env,
size_t mmu_idx, size_t index,
DATA_TYPE val,
target_ulong addr,
uintptr_t retaddr,
bool recheck)
{
CPUIOTLBEntry *iotlbentry = &env->iotlb[mmu_idx][index];
return io_writex(env, iotlbentry, mmu_idx, val, addr, retaddr,
recheck, DATA_SIZE);
}
void helper_le_st_name(CPUArchState *env, target_ulong addr, DATA_TYPE val,
TCGMemOpIdx oi, uintptr_t retaddr)
{
unsigned mmu_idx = get_mmuidx(oi);
int index = (addr >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1);
target_ulong tlb_addr = env->tlb_table[mmu_idx][index].addr_write;
unsigned a_bits = get_alignment_bits(get_memop(oi));
uintptr_t haddr;
if (addr & ((1 << a_bits) - 1)) {
cpu_unaligned_access(ENV_GET_CPU(env), addr, MMU_DATA_STORE,
mmu_idx, retaddr);
}
/* If the TLB entry is for a different page, reload and try again. */
if ((addr & TARGET_PAGE_MASK)
!= (tlb_addr & (TARGET_PAGE_MASK | TLB_INVALID_MASK))) {
if (!VICTIM_TLB_HIT(addr_write, addr)) {
tlb_fill(ENV_GET_CPU(env), addr, DATA_SIZE, MMU_DATA_STORE,
mmu_idx, retaddr);
}
tlb_addr = env->tlb_table[mmu_idx][index].addr_write & ~TLB_INVALID_MASK;
}
/* Handle an IO access. */
if (unlikely(tlb_addr & ~TARGET_PAGE_MASK)) {
if ((addr & (DATA_SIZE - 1)) != 0) {
goto do_unaligned_access;
}
/* ??? Note that the io helpers always read data in the target
byte ordering. We should push the LE/BE request down into io. */
val = TGT_LE(val);
glue(io_write, SUFFIX)(env, mmu_idx, index, val, addr,
retaddr, tlb_addr & TLB_RECHECK);
return;
}
/* Handle slow unaligned access (it spans two pages or IO). */
if (DATA_SIZE > 1
&& unlikely((addr & ~TARGET_PAGE_MASK) + DATA_SIZE - 1
>= TARGET_PAGE_SIZE)) {
int i, index2;
target_ulong page2, tlb_addr2;
do_unaligned_access:
/* Ensure the second page is in the TLB. Note that the first page
is already guaranteed to be filled, and that the second page
cannot evict the first. */
page2 = (addr + DATA_SIZE) & TARGET_PAGE_MASK;
index2 = (page2 >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1);
tlb_addr2 = env->tlb_table[mmu_idx][index2].addr_write;
if (page2 != (tlb_addr2 & (TARGET_PAGE_MASK | TLB_INVALID_MASK))
&& !VICTIM_TLB_HIT(addr_write, page2)) {
tlb_fill(ENV_GET_CPU(env), page2, DATA_SIZE, MMU_DATA_STORE,
mmu_idx, retaddr);
}
/* XXX: not efficient, but simple. */
/* This loop must go in the forward direction to avoid issues
with self-modifying code in Windows 64-bit. */
for (i = 0; i < DATA_SIZE; ++i) {
/* Little-endian extract. */
uint8_t val8 = val >> (i * 8);
glue(helper_ret_stb, MMUSUFFIX)(env, addr + i, val8,
oi, retaddr);
}
return;
}
haddr = addr + env->tlb_table[mmu_idx][index].addend;
#if DATA_SIZE == 1
glue(glue(st, SUFFIX), _p)((uint8_t *)haddr, val);
#else
glue(glue(st, SUFFIX), _le_p)((uint8_t *)haddr, val);
#endif
}
#if DATA_SIZE > 1
void helper_be_st_name(CPUArchState *env, target_ulong addr, DATA_TYPE val,
TCGMemOpIdx oi, uintptr_t retaddr)
{
unsigned mmu_idx = get_mmuidx(oi);
int index = (addr >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1);
target_ulong tlb_addr = env->tlb_table[mmu_idx][index].addr_write;
unsigned a_bits = get_alignment_bits(get_memop(oi));
uintptr_t haddr;
if (addr & ((1 << a_bits) - 1)) {
cpu_unaligned_access(ENV_GET_CPU(env), addr, MMU_DATA_STORE,
mmu_idx, retaddr);
}
/* If the TLB entry is for a different page, reload and try again. */
if ((addr & TARGET_PAGE_MASK)
!= (tlb_addr & (TARGET_PAGE_MASK | TLB_INVALID_MASK))) {
if (!VICTIM_TLB_HIT(addr_write, addr)) {
tlb_fill(ENV_GET_CPU(env), addr, DATA_SIZE, MMU_DATA_STORE,
mmu_idx, retaddr);
}
tlb_addr = env->tlb_table[mmu_idx][index].addr_write & ~TLB_INVALID_MASK;
}
/* Handle an IO access. */
if (unlikely(tlb_addr & ~TARGET_PAGE_MASK)) {
if ((addr & (DATA_SIZE - 1)) != 0) {
goto do_unaligned_access;
}
/* ??? Note that the io helpers always read data in the target
byte ordering. We should push the LE/BE request down into io. */
val = TGT_BE(val);
glue(io_write, SUFFIX)(env, mmu_idx, index, val, addr, retaddr,
tlb_addr & TLB_RECHECK);
return;
}
/* Handle slow unaligned access (it spans two pages or IO). */
if (DATA_SIZE > 1
&& unlikely((addr & ~TARGET_PAGE_MASK) + DATA_SIZE - 1
>= TARGET_PAGE_SIZE)) {
int i, index2;
target_ulong page2, tlb_addr2;
do_unaligned_access:
/* Ensure the second page is in the TLB. Note that the first page
is already guaranteed to be filled, and that the second page
cannot evict the first. */
page2 = (addr + DATA_SIZE) & TARGET_PAGE_MASK;
index2 = (page2 >> TARGET_PAGE_BITS) & (CPU_TLB_SIZE - 1);
tlb_addr2 = env->tlb_table[mmu_idx][index2].addr_write;
if (page2 != (tlb_addr2 & (TARGET_PAGE_MASK | TLB_INVALID_MASK))
&& !VICTIM_TLB_HIT(addr_write, page2)) {
tlb_fill(ENV_GET_CPU(env), page2, DATA_SIZE, MMU_DATA_STORE,
mmu_idx, retaddr);
}
/* XXX: not efficient, but simple */
/* This loop must go in the forward direction to avoid issues
with self-modifying code. */
for (i = 0; i < DATA_SIZE; ++i) {
/* Big-endian extract. */
uint8_t val8 = val >> (((DATA_SIZE - 1) * 8) - (i * 8));
glue(helper_ret_stb, MMUSUFFIX)(env, addr + i, val8,
oi, retaddr);
}
return;
}
haddr = addr + env->tlb_table[mmu_idx][index].addend;
glue(glue(st, SUFFIX), _be_p)((uint8_t *)haddr, val);
}
#endif /* DATA_SIZE > 1 */
#endif /* !defined(SOFTMMU_CODE_ACCESS) */
#undef READ_ACCESS_TYPE
#undef DATA_TYPE
#undef SUFFIX
#undef LSUFFIX
#undef DATA_SIZE
#undef ADDR_READ
#undef WORD_TYPE
#undef SDATA_TYPE
#undef USUFFIX
#undef SSUFFIX
#undef BSWAP
#undef helper_le_ld_name
#undef helper_be_ld_name
#undef helper_le_lds_name
#undef helper_be_lds_name
#undef helper_le_st_name
#undef helper_be_st_name