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tcg/mips: Drop special alignment for code_gen_buffer

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Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2021-08-06 08:20:16 -10:00
parent 5a8f0a5dd2
commit 3d1e8ed011
1 changed files with 0 additions and 91 deletions
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91
tcg/region.c
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@ -467,38 +467,6 @@ static size_t tcg_n_regions(size_t tb_size, unsigned max_cpus)
(DEFAULT_CODE_GEN_BUFFER_SIZE_1 < MAX_CODE_GEN_BUFFER_SIZE \
? DEFAULT_CODE_GEN_BUFFER_SIZE_1 : MAX_CODE_GEN_BUFFER_SIZE)
#ifdef __mips__
/*
* In order to use J and JAL within the code_gen_buffer, we require
* that the buffer not cross a 256MB boundary.
*/
static inline bool cross_256mb(void *addr, size_t size)
{
return ((uintptr_t)addr ^ ((uintptr_t)addr + size)) & ~0x0ffffffful;
}
/*
* We weren't able to allocate a buffer without crossing that boundary,
* so make do with the larger portion of the buffer that doesn't cross.
* Returns the new base and size of the buffer in *obuf and *osize.
*/
static inline void split_cross_256mb(void **obuf, size_t *osize,
void *buf1, size_t size1)
{
void *buf2 = (void *)(((uintptr_t)buf1 + size1) & ~0x0ffffffful);
size_t size2 = buf1 + size1 - buf2;
size1 = buf2 - buf1;
if (size1 < size2) {
size1 = size2;
buf1 = buf2;
}
*obuf = buf1;
*osize = size1;
}
#endif
#ifdef USE_STATIC_CODE_GEN_BUFFER
static uint8_t static_code_gen_buffer[DEFAULT_CODE_GEN_BUFFER_SIZE]
__attribute__((aligned(CODE_GEN_ALIGN)));
@ -526,12 +494,6 @@ static int alloc_code_gen_buffer(size_t tb_size, int splitwx, Error **errp)
size = QEMU_ALIGN_DOWN(tb_size, qemu_real_host_page_size);
}
#ifdef __mips__
if (cross_256mb(buf, size)) {
split_cross_256mb(&buf, &size, buf, size);
}
#endif
region.start_aligned = buf;
region.total_size = size;
@ -573,39 +535,6 @@ static int alloc_code_gen_buffer_anon(size_t size, int prot,
return -1;
}
#ifdef __mips__
if (cross_256mb(buf, size)) {
/*
* Try again, with the original still mapped, to avoid re-acquiring
* the same 256mb crossing.
*/
size_t size2;
void *buf2 = mmap(NULL, size, prot, flags, -1, 0);
switch ((int)(buf2 != MAP_FAILED)) {
case 1:
if (!cross_256mb(buf2, size)) {
/* Success! Use the new buffer. */
munmap(buf, size);
break;
}
/* Failure. Work with what we had. */
munmap(buf2, size);
/* fallthru */
default:
/* Split the original buffer. Free the smaller half. */
split_cross_256mb(&buf2, &size2, buf, size);
if (buf == buf2) {
munmap(buf + size2, size - size2);
} else {
munmap(buf, size - size2);
}
size = size2;
break;
}
buf = buf2;
}
#endif
region.start_aligned = buf;
region.total_size = size;
return prot;
@ -620,35 +549,15 @@ static bool alloc_code_gen_buffer_splitwx_memfd(size_t size, Error **errp)
void *buf_rw = NULL, *buf_rx = MAP_FAILED;
int fd = -1;
#ifdef __mips__
/* Find space for the RX mapping, vs the 256MiB regions. */
if (alloc_code_gen_buffer_anon(size, PROT_NONE,
MAP_PRIVATE | MAP_ANONYMOUS |
MAP_NORESERVE, errp) < 0) {
return false;
}
/* The size of the mapping may have been adjusted. */
buf_rx = region.start_aligned;
size = region.total_size;
#endif
buf_rw = qemu_memfd_alloc("tcg-jit", size, 0, &fd, errp);
if (buf_rw == NULL) {
goto fail;
}
#ifdef __mips__
void *tmp = mmap(buf_rx, size, PROT_READ | PROT_EXEC,
MAP_SHARED | MAP_FIXED, fd, 0);
if (tmp != buf_rx) {
goto fail_rx;
}
#else
buf_rx = mmap(NULL, size, PROT_READ | PROT_EXEC, MAP_SHARED, fd, 0);
if (buf_rx == MAP_FAILED) {
goto fail_rx;
}
#endif
close(fd);
region.start_aligned = buf_rw;