On 12/18/25 01:31, Philippe Mathieu-Daudé wrote:
> Replace the ldn_p/stn_p() calls by their explicit endianness
> variants. Duplicate the MemoryRegionOps, replacing the single
> DEVICE_NATIVE_ENDIAN entry by a pair of LITTLE and BIG ones.
> Select the proper MemoryRegionOps in subpage_init().
>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> ---
> system/physmem.c | 81 ++++++++++++++++++++++++++++++++++++++----------
> 1 file changed, 64 insertions(+), 17 deletions(-)
>
> diff --git a/system/physmem.c b/system/physmem.c
> index 1292f49095f..d8465f085bd 100644
> --- a/system/physmem.c
> +++ b/system/physmem.c
> @@ -2896,8 +2896,8 @@ static MemTxResult flatview_write(FlatView *fv, hwaddr addr, MemTxAttrs attrs,
> static bool flatview_access_valid(FlatView *fv, hwaddr addr, hwaddr len,
> bool is_write, MemTxAttrs attrs);
>
> -static MemTxResult subpage_read(void *opaque, hwaddr addr, uint64_t *data,
> - unsigned len, MemTxAttrs attrs)
> +static MemTxResult subpage_read_le(void *opaque, hwaddr addr, uint64_t *data,
> + unsigned len, MemTxAttrs attrs)
> {
> subpage_t *subpage = opaque;
> uint8_t buf[8];
> @@ -2911,12 +2911,32 @@ static MemTxResult subpage_read(void *opaque, hwaddr addr, uint64_t *data,
> if (res) {
> return res;
> }
> - *data = ldn_p(buf, len);
> + *data = ldn_le_p(buf, len);
> return MEMTX_OK;
> }
>
> -static MemTxResult subpage_write(void *opaque, hwaddr addr,
> - uint64_t value, unsigned len, MemTxAttrs attrs)
> +static MemTxResult subpage_read_be(void *opaque, hwaddr addr, uint64_t *data,
> + unsigned len, MemTxAttrs attrs)
> +{
> + subpage_t *subpage = opaque;
> + uint8_t buf[8];
> + MemTxResult res;
> +
> +#if defined(DEBUG_SUBPAGE)
> + printf("%s: subpage %p len %u addr " HWADDR_FMT_plx "\n", __func__,
> + subpage, len, addr);
> +#endif
It would be worth converting these to trace points before replicating.
Otherwise,
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
r~
> + res = flatview_read(subpage->fv, addr + subpage->base, attrs, buf, len);
> + if (res) {
> + return res;
> + }
> + *data = ldn_be_p(buf, len);
> + return MEMTX_OK;
> +}
> +
> +static MemTxResult subpage_write_le(void *opaque, hwaddr addr,
> + uint64_t value, unsigned len,
> + MemTxAttrs attrs)
> {
> subpage_t *subpage = opaque;
> uint8_t buf[8];
> @@ -2926,7 +2946,23 @@ static MemTxResult subpage_write(void *opaque, hwaddr addr,
> " value %"PRIx64"\n",
> __func__, subpage, len, addr, value);
> #endif
> - stn_p(buf, len, value);
> + stn_le_p(buf, len, value);
> + return flatview_write(subpage->fv, addr + subpage->base, attrs, buf, len);
> +}
> +
> +static MemTxResult subpage_write_be(void *opaque, hwaddr addr,
> + uint64_t value, unsigned len,
> + MemTxAttrs attrs)
> +{
> + subpage_t *subpage = opaque;
> + uint8_t buf[8];
> +
> +#if defined(DEBUG_SUBPAGE)
> + printf("%s: subpage %p len %u addr " HWADDR_FMT_plx
> + " value %"PRIx64"\n",
> + __func__, subpage, len, addr, value);
> +#endif
> + stn_be_p(buf, len, value);
> return flatview_write(subpage->fv, addr + subpage->base, attrs, buf, len);
> }
>
> @@ -2944,15 +2980,26 @@ static bool subpage_accepts(void *opaque, hwaddr addr,
> len, is_write, attrs);
> }
>
> -static const MemoryRegionOps subpage_ops = {
> - .read_with_attrs = subpage_read,
> - .write_with_attrs = subpage_write,
> - .impl.min_access_size = 1,
> - .impl.max_access_size = 8,
> - .valid.min_access_size = 1,
> - .valid.max_access_size = 8,
> - .valid.accepts = subpage_accepts,
> - .endianness = DEVICE_NATIVE_ENDIAN,
> +static const MemoryRegionOps subpage_ops[2] = {
> + [0 ... 1] = {
> + .impl = {
> + .min_access_size = 1,
> + .max_access_size = 8,
> + },
> + .valid = {
> + .min_access_size = 1,
> + .max_access_size = 8,
> + .accepts = subpage_accepts,
> + },
> + },
> +
> + [0].endianness = DEVICE_LITTLE_ENDIAN,
> + [0].read_with_attrs = subpage_read_le,
> + [0].write_with_attrs = subpage_write_le,
> +
> + [1].endianness = DEVICE_BIG_ENDIAN,
> + [1].read_with_attrs = subpage_read_be,
> + [1].write_with_attrs = subpage_write_be,
> };
>
> static int subpage_register(subpage_t *mmio, uint32_t start, uint32_t end,
> @@ -2983,8 +3030,8 @@ static subpage_t *subpage_init(FlatView *fv, hwaddr base)
> mmio = g_malloc0(sizeof(subpage_t) + TARGET_PAGE_SIZE * sizeof(uint16_t));
> mmio->fv = fv;
> mmio->base = base;
> - memory_region_init_io(&mmio->iomem, NULL, &subpage_ops, mmio,
> - NULL, TARGET_PAGE_SIZE);
> + memory_region_init_io(&mmio->iomem, NULL, &subpage_ops[target_big_endian()],
> + mmio, NULL, TARGET_PAGE_SIZE);
> mmio->iomem.subpage = true;
> #if defined(DEBUG_SUBPAGE)
> printf("%s: %p base " HWADDR_FMT_plx " len %08x\n", __func__,