Il 09/07/2013 03:01, Richard Henderson ha scritto:
> Honor the implementation maximum access size, and at least check
> the minimum access size.
>
> Signed-off-by: Richard Henderson <r...@twiddle.net>
> ---
> exec.c | 68
> ++++++++++++++++++++++++++++++++++++++++++++++++++++++------------
> 1 file changed, 56 insertions(+), 12 deletions(-)
>
> diff --git a/exec.c b/exec.c
> index 03fdf7e..5da22dc 100644
> --- a/exec.c
> +++ b/exec.c
> @@ -1902,15 +1902,37 @@ 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,
> @@ -1932,18 +1954,29 @@ bool address_space_rw(AddressSpace *as, hwaddr addr,
> uint8_t *buf,
> l = memory_access_size(mr, l, addr1);
> /* XXX: could force cpu_single_env 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);
> @@ -1956,18 +1989,29 @@ 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 */
>
Reviewed-by: Paolo Bonzini <pbonz...@redhat.com>
