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memory: Single byte swap along the I/O path

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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.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Suggested-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Tony Nguyen <tony.nguyen@bt.com>
Message-Id: <911ff31af11922a9afba9b7ce128af8b8b80f316.1566466906.git.tony.nguyen@bt.com>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Tony Nguyen 2019-08-24 04:36:54 +10:00 • committed by Richard Henderson
parent be5c4787e9
commit 9bf825bf3d
5 changed files with 23 additions and 142 deletions
Download patch file Download diff file Expand all files Collapse all files

33
memory.c
View file

@ -351,32 +351,23 @@ 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();
}
}
}
@ -1458,7 +1449,7 @@ 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;
}
@ -1501,7 +1492,7 @@ MemTxResult memory_region_dispatch_write(MemoryRegion *mr,
return MEMTX_DECODE_ERROR;
}
adjust_endianness(mr, &data, size);
adjust_endianness(mr, &data, op);
if ((!kvm_eventfds_enabled()) &&
memory_region_dispatch_write_eventfds(mr, addr, data, size, attrs)) {
@ -2350,7 +2341,7 @@ void memory_region_add_eventfd(MemoryRegion *mr,
}
if (size) {
adjust_endianness(mr, &mrfd.data, size);
adjust_endianness(mr, &mrfd.data, size_memop(size) | MO_TE);
}
memory_region_transaction_begin();
for (i = 0; i < mr->ioeventfd_nb; ++i) {
@ -2385,7 +2376,7 @@ void memory_region_del_eventfd(MemoryRegion *mr,
unsigned i;
if (size) {
adjust_endianness(mr, &mrfd.data, size);
adjust_endianness(mr, &mrfd.data, size_memop(size) | MO_TE);
}
memory_region_transaction_begin();
for (i = 0; i < mr->ioeventfd_nb; ++i) {