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authorRichard Henderson <rth@twiddle.net>2013-07-08 14:55:59 -0700
committerRichard Henderson <rth@twiddle.net>2013-07-14 13:40:31 -0700
commit23326164ae6fe8d94b7eff123e03f97ca6978d33 (patch)
tree4f62b99d59b55277be0609748f0c1a5ebd3359db /exec.c
parent3661049fec64ffd7ab008e57e396881c6a4b53a4 (diff)
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exec: Support 64-bit operations in address_space_rw
Honor the implementation maximum access size, and at least check the minimum access size. Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Richard Henderson <rth@twiddle.net>
Diffstat (limited to 'exec.c')
-rw-r--r--exec.c68
1 files changed, 56 insertions, 12 deletions
diff --git a/exec.c b/exec.c
index 80ee2ab..c99a883 100644
--- a/exec.c
+++ b/exec.c
@@ -1896,15 +1896,37 @@ static inline bool memory_access_is_direct(MemoryRegion *mr, bool is_write)
return false;
}
-static inline int memory_access_size(MemoryRegion *mr, int l, hwaddr addr)
+static int memory_access_size(MemoryRegion *mr, unsigned l, hwaddr addr)
{
- if (l >= 4 && (((addr & 3) == 0 || mr->ops->impl.unaligned))) {
- return 4;
+ unsigned access_size_min = mr->ops->impl.min_access_size;
+ unsigned access_size_max = mr->ops->impl.max_access_size;
+
+ /* Regions are assumed to support 1-4 byte accesses unless
+ otherwise specified. */
+ if (access_size_min == 0) {
+ access_size_min = 1;
+ }
+ if (access_size_max == 0) {
+ access_size_max = 4;
+ }
+
+ /* Bound the maximum access by the alignment of the address. */
+ if (!mr->ops->impl.unaligned) {
+ unsigned align_size_max = addr & -addr;
+ if (align_size_max != 0 && align_size_max < access_size_max) {
+ access_size_max = align_size_max;
+ }
}
- if (l >= 2 && (((addr & 1) == 0) || mr->ops->impl.unaligned)) {
- return 2;
+
+ /* Don't attempt accesses larger than the maximum. */
+ if (l > access_size_max) {
+ l = access_size_max;
}
- return 1;
+ /* ??? The users of this function are wrong, not supporting minimums larger
+ than the remaining length. C.f. memory.c:access_with_adjusted_size. */
+ assert(l >= access_size_min);
+
+ return l;
}
bool address_space_rw(AddressSpace *as, hwaddr addr, uint8_t *buf,
@@ -1926,18 +1948,29 @@ bool address_space_rw(AddressSpace *as, hwaddr addr, uint8_t *buf,
l = memory_access_size(mr, l, addr1);
/* XXX: could force current_cpu to NULL to avoid
potential bugs */
- if (l == 4) {
+ switch (l) {
+ case 8:
+ /* 64 bit write access */
+ val = ldq_p(buf);
+ error |= io_mem_write(mr, addr1, val, 8);
+ break;
+ case 4:
/* 32 bit write access */
val = ldl_p(buf);
error |= io_mem_write(mr, addr1, val, 4);
- } else if (l == 2) {
+ break;
+ case 2:
/* 16 bit write access */
val = lduw_p(buf);
error |= io_mem_write(mr, addr1, val, 2);
- } else {
+ break;
+ case 1:
/* 8 bit write access */
val = ldub_p(buf);
error |= io_mem_write(mr, addr1, val, 1);
+ break;
+ default:
+ abort();
}
} else {
addr1 += memory_region_get_ram_addr(mr);
@@ -1950,18 +1983,29 @@ bool address_space_rw(AddressSpace *as, hwaddr addr, uint8_t *buf,
if (!memory_access_is_direct(mr, is_write)) {
/* I/O case */
l = memory_access_size(mr, l, addr1);
- if (l == 4) {
+ switch (l) {
+ case 8:
+ /* 64 bit read access */
+ error |= io_mem_read(mr, addr1, &val, 8);
+ stq_p(buf, val);
+ break;
+ case 4:
/* 32 bit read access */
error |= io_mem_read(mr, addr1, &val, 4);
stl_p(buf, val);
- } else if (l == 2) {
+ break;
+ case 2:
/* 16 bit read access */
error |= io_mem_read(mr, addr1, &val, 2);
stw_p(buf, val);
- } else {
+ break;
+ case 1:
/* 8 bit read access */
error |= io_mem_read(mr, addr1, &val, 1);
stb_p(buf, val);
+ break;
+ default:
+ abort();
}
} else {
/* RAM case */