Re: [Qemu-devel] [PATCH 1/5] lsi: use ldn_le_p()/stn_le_p()

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

On 3/4/19 7:09 PM, Sven Schnelle wrote:
> Signed-off-by: Sven Schnelle <svens@stackframe.org>
> ---
>  hw/scsi/lsi53c895a.c | 24 ++++--------------------
>  1 file changed, 4 insertions(+), 20 deletions(-)
> 
> diff --git a/hw/scsi/lsi53c895a.c b/hw/scsi/lsi53c895a.c
> index 25c6926039..6d280f8b77 100644
> --- a/hw/scsi/lsi53c895a.c
> +++ b/hw/scsi/lsi53c895a.c
> @@ -289,8 +289,7 @@ typedef struct {
>      uint8_t sbr;
>      uint32_t adder;
>  
> -    /* Script ram is stored as 32-bit words in host byteorder.  */
> -    uint32_t script_ram[2048];
> +    uint8_t script_ram[8192];

I'm tempted to use here:

       uint8_t script_ram[2048 * sizeof(uint32_t)];

>  } LSIState;
>  
>  #define TYPE_LSI53C810  "lsi53c810"
> @@ -2077,29 +2076,14 @@ static void lsi_ram_write(void *opaque, hwaddr addr,
>                            uint64_t val, unsigned size)
>  {
>      LSIState *s = opaque;
> -    uint32_t newval;
> -    uint32_t mask;
> -    int shift;
> -
> -    newval = s->script_ram[addr >> 2];
> -    shift = (addr & 3) * 8;
> -    mask = ((uint64_t)1 << (size * 8)) - 1;
> -    newval &= ~(mask << shift);
> -    newval |= val << shift;
> -    s->script_ram[addr >> 2] = newval;
> +    stn_le_p(s->script_ram + addr, size, val);
>  }
>  
>  static uint64_t lsi_ram_read(void *opaque, hwaddr addr,
>                               unsigned size)
>  {
>      LSIState *s = opaque;
> -    uint32_t val;
> -    uint32_t mask;
> -

Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>

> -    val = s->script_ram[addr >> 2];
> -    mask = ((uint64_t)1 << (size * 8)) - 1;
> -    val >>= (addr & 3) * 8;
> -    return val & mask;
> +    return ldn_le_p(s->script_ram + addr, size);
>  }
>  
>  static const MemoryRegionOps lsi_ram_ops = {
> @@ -2242,7 +2226,7 @@ static const VMStateDescription vmstate_lsi_scsi = {
>          VMSTATE_BUFFER_UNSAFE(scratch, LSIState, 0, 18 * sizeof(uint32_t)),
>          VMSTATE_UINT8(sbr, LSIState),
>  
> -        VMSTATE_BUFFER_UNSAFE(script_ram, LSIState, 0, 2048 * sizeof(uint32_t)),
> +        VMSTATE_BUFFER_UNSAFE(script_ram, LSIState, 0, 8192),
>          VMSTATE_END_OF_LIST()
>      }
>  };
>