A size is easier to work with than an end point,
particularly during initial buffer allocation.
Signed-off-by: Richard Henderson <richard.hender...@linaro.org>
---
tcg/region.c | 29 +++++++++++++++++------------
1 file changed, 17 insertions(+), 12 deletions(-)
diff --git a/tcg/region.c b/tcg/region.c
index ae22308290..8e4dd0480b 100644
--- a/tcg/region.c
+++ b/tcg/region.c
@@ -48,7 +48,7 @@ struct tcg_region_state {
/* fields set at init time */
void *start;
void *start_aligned;
- void *end;
+ size_t total_size; /* size of entire buffer */
size_t n;
size_t size; /* size of one region */
size_t stride; /* .size + guard size */
@@ -279,7 +279,7 @@ static void tcg_region_bounds(size_t curr_region, void
**pstart, void **pend)
start = region.start;
}
if (curr_region == region.n - 1) {
- end = region.end;
+ end = region.start_aligned + region.total_size;
}
*pstart = start;
@@ -813,8 +813,8 @@ static bool alloc_code_gen_buffer(size_t size, int splitwx,
Error **errp)
*/
void tcg_region_init(size_t tb_size, int splitwx, unsigned max_cpus)
{
- void *buf, *aligned;
- size_t size;
+ void *buf, *aligned, *end;
+ size_t total_size;
size_t page_size;
size_t region_size;
size_t n_regions;
@@ -827,19 +827,20 @@ void tcg_region_init(size_t tb_size, int splitwx,
unsigned max_cpus)
assert(ok);
buf = tcg_init_ctx.code_gen_buffer;
- size = tcg_init_ctx.code_gen_buffer_size;
+ total_size = tcg_init_ctx.code_gen_buffer_size;
page_size = qemu_real_host_page_size;
n_regions = tcg_n_regions(max_cpus);
/* The first region will be 'aligned - buf' bytes larger than the others */
aligned = QEMU_ALIGN_PTR_UP(buf, page_size);
- g_assert(aligned < tcg_init_ctx.code_gen_buffer + size);
+ g_assert(aligned < tcg_init_ctx.code_gen_buffer + total_size);
+
/*
* Make region_size a multiple of page_size, using aligned as the start.
* As a result of this we might end up with a few extra pages at the end of
* the buffer; we will assign those to the last region.
*/
- region_size = (size - (aligned - buf)) / n_regions;
+ region_size = (total_size - (aligned - buf)) / n_regions;
region_size = QEMU_ALIGN_DOWN(region_size, page_size);
/* A region must have at least 2 pages; one code, one guard */
@@ -853,9 +854,11 @@ void tcg_region_init(size_t tb_size, int splitwx, unsigned
max_cpus)
region.start = buf;
region.start_aligned = aligned;
/* page-align the end, since its last page will be a guard page */
- region.end = QEMU_ALIGN_PTR_DOWN(buf + size, page_size);
+ end = QEMU_ALIGN_PTR_DOWN(buf + total_size, page_size);
/* account for that last guard page */
- region.end -= page_size;
+ end -= page_size;
+ total_size = end - aligned;
+ region.total_size = total_size;
/* set guard pages */
splitwx_diff = tcg_splitwx_diff;
@@ -893,7 +896,7 @@ void tcg_region_prologue_set(TCGContext *s)
/* Register the balance of the buffer with gdb. */
tcg_register_jit(tcg_splitwx_to_rx(region.start),
- region.end - region.start);
+ region.start_aligned + region.total_size - region.start);
}
/*
@@ -934,8 +937,10 @@ size_t tcg_code_capacity(void)
/* no need for synchronization; these variables are set at init time */
guard_size = region.stride - region.size;
- capacity = region.end + guard_size - region.start;
- capacity -= region.n * (guard_size + TCG_HIGHWATER);
+ capacity = region.total_size;
+ capacity -= (region.n - 1) * guard_size;
+ capacity -= region.n * TCG_HIGHWATER;
+
return capacity;
}
--
2.25.1
