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[Qemu-devel] [PATCH 2/4] memory: streamline common case for memory dispa
From: |
Paolo Bonzini |
Subject: |
[Qemu-devel] [PATCH 2/4] memory: streamline common case for memory dispatch |
Date: |
Mon, 2 Dec 2013 15:40:26 +0100 |
In the common case where there is no combining or splitting,
access_with_adjusted_size is adding a lot of overhead. Call
the MMIO ops directly in that case.
Signed-off-by: Paolo Bonzini <address@hidden>
---
memory.c | 68 ++++++++++++++++++++++++++++++++++++++++++++++++++++------------
1 file changed, 56 insertions(+), 12 deletions(-)
diff --git a/memory.c b/memory.c
index 56e54aa..1ade19c 100644
--- a/memory.c
+++ b/memory.c
@@ -443,6 +443,7 @@ static void memory_region_write_accessor(MemoryRegion *mr,
static void access_with_adjusted_size(hwaddr addr,
uint64_t *value,
unsigned size,
+ unsigned access_size,
void (*access)(MemoryRegion *mr,
hwaddr addr,
uint64_t *value,
@@ -452,11 +453,9 @@ static void access_with_adjusted_size(hwaddr addr,
MemoryRegion *mr)
{
uint64_t access_mask;
- unsigned access_size;
unsigned i;
/* FIXME: support unaligned access? */
- access_size = MAX(MIN(size, mr->min_access_size), mr->min_access_size);
access_mask = -1ULL >> (64 - access_size * 8);
if (memory_region_big_endian(mr)) {
for (i = 0; i < size; i += access_size) {
@@ -929,13 +928,32 @@ static uint64_t memory_region_dispatch_read1(MemoryRegion
*mr,
hwaddr addr,
unsigned size)
{
+ unsigned access_size;
uint64_t data = 0;
+ if (size < mr->min_access_size) {
+ access_size = mr->min_access_size;
+ goto adjusted;
+ }
+ if (size > mr->max_access_size) {
+ access_size = mr->max_access_size;
+ goto adjusted;
+ }
+
+ if (mr->ops->read) {
+ data = mr->ops->read(mr->opaque, addr, size);
+ } else {
+ data = mr->ops->old_mmio.read[ctz32(size)](mr->opaque, addr);
+ }
+ trace_memory_region_ops_read(mr, addr, data, size);
+ return data;
+
+adjusted:
if (mr->ops->read) {
- access_with_adjusted_size(addr, &data, size,
+ access_with_adjusted_size(addr, &data, size, access_size,
memory_region_read_accessor, mr);
} else {
- access_with_adjusted_size(addr, &data, size,
+ access_with_adjusted_size(addr, &data, size, access_size,
memory_region_oldmmio_read_accessor, mr);
}
@@ -957,6 +975,39 @@ static bool memory_region_dispatch_read(MemoryRegion *mr,
return false;
}
+static void memory_region_dispatch_write1(MemoryRegion *mr,
+ hwaddr addr,
+ uint64_t data,
+ unsigned size)
+{
+ unsigned access_size;
+ if (size < mr->min_access_size) {
+ access_size = mr->min_access_size;
+ goto adjusted;
+ }
+ if (size > mr->max_access_size) {
+ access_size = mr->max_access_size;
+ goto adjusted;
+ }
+
+ trace_memory_region_ops_write(mr, addr, data, size);
+ if (mr->ops->write) {
+ mr->ops->write(mr->opaque, addr, data, size);
+ } else {
+ mr->ops->old_mmio.write[ctz32(size)](mr->opaque, addr, data);
+ }
+ return;
+
+adjusted:
+ if (mr->ops->write) {
+ access_with_adjusted_size(addr, &data, size, access_size,
+ memory_region_write_accessor, mr);
+ } else {
+ access_with_adjusted_size(addr, &data, size, access_size,
+ memory_region_oldmmio_write_accessor, mr);
+ }
+}
+
static bool memory_region_dispatch_write(MemoryRegion *mr,
hwaddr addr,
uint64_t data,
@@ -968,14 +1019,7 @@ static bool memory_region_dispatch_write(MemoryRegion *mr,
}
adjust_endianness(mr, &data, size);
-
- if (mr->ops->write) {
- access_with_adjusted_size(addr, &data, size,
- memory_region_write_accessor, mr);
- } else {
- access_with_adjusted_size(addr, &data, size,
- memory_region_oldmmio_write_accessor, mr);
- }
+ memory_region_dispatch_write1(mr, addr, data, size);
return false;
}
--
1.8.4.2