memory: Single byte swap along the I/O path

Now that MemOp has been pushed down into the memory API, and
callers are encoding endianness, we can collapse byte swaps
along the I/O path into the accelerator and target independent
adjust_endianness.

Collapsing byte swaps along the I/O path enables additional endian
inversion logic, e.g. SPARC64 Invert Endian TTE bit, with redundant
byte swaps cancelling out.

Backports commit 9bf825bf3df4ebae3af51566c8088e3f1249a910 from qemu
This commit is contained in:
Tony Nguyen 2020-01-07 19:12:01 -05:00 committed by Lioncash
parent ad8957a4c3
commit 103d6f51c8
4 changed files with 17 additions and 136 deletions

View file

@ -834,38 +834,6 @@ static void *atomic_mmu_lookup(CPUArchState *env, target_ulong addr,
cpu_loop_exit_atomic(env_cpu(env), retaddr);
}
#ifdef TARGET_WORDS_BIGENDIAN
#define NEED_BE_BSWAP 0
#define NEED_LE_BSWAP 1
#else
#define NEED_BE_BSWAP 1
#define NEED_LE_BSWAP 0
#endif
/*
* Byte Swap Helper
*
* This should all dead code away depending on the build host and
* access type.
*/
static inline uint64_t handle_bswap(uint64_t val, MemOp op)
{
if ((memop_big_endian(op) && NEED_BE_BSWAP) ||
(!memop_big_endian(op) && NEED_LE_BSWAP)) {
switch (op & MO_SIZE) {
case MO_8: return val;
case MO_16: return bswap16(val);
case MO_32: return bswap32(val);
case MO_64: return bswap64(val);
default:
g_assert_not_reached();
}
} else {
return val;
}
}
/*
* Load Helpers
*
@ -1045,10 +1013,8 @@ load_helper(CPUArchState *env, target_ulong addr, TCGMemOpIdx oi,
}
}
/* TODO: Merge bswap into io_readx -> memory_region_dispatch_read. */
res = io_readx(env, &env->iotlb[mmu_idx][index], mmu_idx, addr,
return io_readx(env, &env->iotlb[mmu_idx][index],
mmu_idx, addr, retaddr, access_type, op);
return handle_bswap(res, op);
}
/* Handle slow unaligned access (it spans two pages or IO). */
@ -1366,10 +1332,8 @@ store_helper(CPUArchState *env, target_ulong addr, uint64_t val,
}
}
/* TODO: Merge bswap into io_writex -> memory_region_dispatch_write. */
io_writex(env, &env->iotlb[mmu_idx][index], mmu_idx,
handle_bswap(val, op),
addr, retaddr, op);
val, addr, retaddr, op);
return;
}

View file

@ -1957,16 +1957,9 @@ static MemTxResult flatview_write_continue(FlatView *fv, hwaddr addr,
// Unicorn: commented out
//release_lock |= prepare_mmio_access(mr);
l = memory_access_size(mr, l, addr1);
/* XXX: could force current_cpu to NULL to avoid
potential bugs */
val = ldn_p(buf, l);
/*
* TODO: Merge bswap from ldn_p into memory_region_dispatch_write
* by using ldn_he_p and dropping MO_TE to get a host-endian value.
*/
val = ldn_he_p(buf, l);
result |= memory_region_dispatch_write(mr, addr1, val,
size_memop(l) | MO_TE,
attrs);
size_memop(l), attrs);
} else {
/* RAM case */
ptr = qemu_map_ram_ptr(mr->uc, mr->ram_block, addr1);
@ -2042,13 +2035,9 @@ MemTxResult flatview_read_continue(FlatView *fv, hwaddr addr,
// Unicorn: commented out
//release_lock |= prepare_mmio_access(mr);
l = memory_access_size(mr, l, addr1);
/*
* TODO: Merge bswap from stn_p into memory_region_dispatch_read
* by using stn_he_p and dropping MO_TE to get a host-endian value.
*/
result |= memory_region_dispatch_read(mr, addr1, &val,
size_memop(l) | MO_TE, attrs);
stn_p(buf, l, val);
size_memop(l), attrs);
stn_he_p(buf, l, val);
} else {
/* RAM case */
ptr = qemu_map_ram_ptr(mr->uc, mr->ram_block, addr1);

View file

@ -413,32 +413,23 @@ static bool memory_region_big_endian(MemoryRegion *mr)
#endif
}
static bool memory_region_wrong_endianness(MemoryRegion *mr)
static void adjust_endianness(MemoryRegion *mr, uint64_t *data, MemOp op)
{
#ifdef TARGET_WORDS_BIGENDIAN
return mr->ops->endianness == DEVICE_LITTLE_ENDIAN;
#else
return mr->ops->endianness == DEVICE_BIG_ENDIAN;
#endif
}
static void adjust_endianness(MemoryRegion *mr, uint64_t *data, unsigned size)
{
if (memory_region_wrong_endianness(mr)) {
switch (size) {
case 1:
if ((op & MO_BSWAP) != devend_memop(mr->ops->endianness)) {
switch (op & MO_SIZE) {
case MO_8:
break;
case 2:
case MO_16:
*data = bswap16(*data);
break;
case 4:
case MO_32:
*data = bswap32(*data);
break;
case 8:
case MO_64:
*data = bswap64(*data);
break;
default:
abort();
g_assert_not_reached();
}
}
}
@ -1319,7 +1310,7 @@ MemTxResult memory_region_dispatch_read(MemoryRegion *mr,
}
r = memory_region_dispatch_read1(mr, addr, pval, size, attrs);
adjust_endianness(mr, pval, size);
adjust_endianness(mr, pval, op);
return r;
}
@ -1336,7 +1327,7 @@ MemTxResult memory_region_dispatch_write(MemoryRegion *mr,
return MEMTX_DECODE_ERROR;
}
adjust_endianness(mr, &data, size);
adjust_endianness(mr, &data, op);
if (mr->ops->write) {
return access_with_adjusted_size(addr, &data, size,

View file

@ -42,18 +42,8 @@ static inline uint32_t glue(address_space_ldl_internal, SUFFIX)(ARG1_DECL,
//release_lock |= prepare_mmio_access(mr);
/* I/O case */
/* TODO: Merge bswap32 into memory_region_dispatch_read. */
r = memory_region_dispatch_read(mr, addr1, &val,
MO_32 | devend_memop(endian), attrs);
#if defined(TARGET_WORDS_BIGENDIAN)
if (endian == DEVICE_LITTLE_ENDIAN) {
val = bswap32(val);
}
#else
if (endian == DEVICE_BIG_ENDIAN) {
val = bswap32(val);
}
#endif
} else {
/* RAM case */
ptr = qemu_map_ram_ptr(mr->uc, mr->ram_block, addr1);
@ -144,18 +134,8 @@ static inline uint64_t glue(address_space_ldq_internal, SUFFIX)(ARG1_DECL,
//release_lock |= prepare_mmio_access(mr);
/* I/O case */
/* TODO: Merge bswap64 into memory_region_dispatch_read. */
r = memory_region_dispatch_read(mr, addr1, &val,
MO_64 | devend_memop(endian), attrs);
#if defined(TARGET_WORDS_BIGENDIAN)
if (endian == DEVICE_LITTLE_ENDIAN) {
val = bswap64(val);
}
#else
if (endian == DEVICE_BIG_ENDIAN) {
val = bswap64(val);
}
#endif
} else {
/* RAM case */
ptr = qemu_map_ram_ptr(mr->uc, mr->ram_block, addr1);
@ -292,18 +272,8 @@ static inline uint32_t glue(address_space_lduw_internal, SUFFIX)(ARG1_DECL,
//release_lock |= prepare_mmio_access(mr);
/* I/O case */
/* TODO: Merge bswap16 into memory_region_dispatch_read. */
r = memory_region_dispatch_read(mr, addr1, &val,
MO_16 | devend_memop(endian), attrs);
#if defined(TARGET_WORDS_BIGENDIAN)
if (endian == DEVICE_LITTLE_ENDIAN) {
val = bswap16(val);
}
#else
if (endian == DEVICE_BIG_ENDIAN) {
val = bswap16(val);
}
#endif
} else {
/* RAM case */
ptr = qemu_map_ram_ptr(mr->uc, mr->ram_block, addr1);
@ -436,17 +406,6 @@ static inline void glue(address_space_stl_internal, SUFFIX)(ARG1_DECL,
if (l < 4 || !memory_access_is_direct(mr, true)) {
// Unicorn: commented out
//release_lock |= prepare_mmio_access(mr);
#if defined(TARGET_WORDS_BIGENDIAN)
if (endian == DEVICE_LITTLE_ENDIAN) {
val = bswap32(val);
}
#else
if (endian == DEVICE_BIG_ENDIAN) {
val = bswap32(val);
}
#endif
/* TODO: Merge bswap32 into memory_region_dispatch_write. */
r = memory_region_dispatch_write(mr, addr1, val,
MO_32 | devend_memop(endian), attrs);
} else {
@ -579,17 +538,6 @@ static inline void glue(address_space_stw_internal, SUFFIX)(ARG1_DECL,
if (l < 2 || !memory_access_is_direct(mr, true)) {
// Unicorn: commented out
//release_lock |= prepare_mmio_access(mr);
#if defined(TARGET_WORDS_BIGENDIAN)
if (endian == DEVICE_LITTLE_ENDIAN) {
val = bswap16(val);
}
#else
if (endian == DEVICE_BIG_ENDIAN) {
val = bswap16(val);
}
#endif
/* TODO: Merge bswap16 into memory_region_dispatch_write. */
r = memory_region_dispatch_write(mr, addr1, val,
MO_16 | devend_memop(endian), attrs);
} else {
@ -678,17 +626,6 @@ static void glue(address_space_stq_internal, SUFFIX)(ARG1_DECL,
if (l < 8 || !memory_access_is_direct(mr, true)) {
// Unicorn: commented out
//release_lock |= prepare_mmio_access(mr);
#if defined(TARGET_WORDS_BIGENDIAN)
if (endian == DEVICE_LITTLE_ENDIAN) {
val = bswap64(val);
}
#else
if (endian == DEVICE_BIG_ENDIAN) {
val = bswap64(val);
}
#endif
/* TODO: Merge bswap64 into memory_region_dispatch_write. */
r = memory_region_dispatch_write(mr, addr1, val,
MO_64 | devend_memop(endian), attrs);
} else {