Re: [PATCH for-5.2 18/19] aspeed/sdmc: Simplify calculation of RAM bits

[Joel Stanley]

On Thu, 6 Aug 2020 at 13:21, Cédric Le Goater <clg@kaod.org> wrote:
>
> Changes in commit 533eb415df2e ("arm/aspeed: actually check RAM size")
> introduced a 'valid_ram_sizes' array which can be used to compute the
> associated bit field value encoding the RAM size. The field is simply
> the index of the array.
>
> Signed-off-by: Cédric Le Goater <clg@kaod.org>

Reviewed-by: Joel Stanley <joel@jms.id.au>

> ---
>  hw/misc/aspeed_sdmc.c | 79 ++++++++++++++-----------------------------
>  1 file changed, 25 insertions(+), 54 deletions(-)
>
> diff --git a/hw/misc/aspeed_sdmc.c b/hw/misc/aspeed_sdmc.c
> index 81c73450ab5d..08f856cbda7e 100644
> --- a/hw/misc/aspeed_sdmc.c
> +++ b/hw/misc/aspeed_sdmc.c
> @@ -159,57 +159,6 @@ static const MemoryRegionOps aspeed_sdmc_ops = {
>      .valid.max_access_size = 4,
>  };
>
> -static int ast2400_rambits(AspeedSDMCState *s)
> -{
> -    switch (s->ram_size >> 20) {
> -    case 64:
> -        return ASPEED_SDMC_DRAM_64MB;
> -    case 128:
> -        return ASPEED_SDMC_DRAM_128MB;
> -    case 256:
> -        return ASPEED_SDMC_DRAM_256MB;
> -    case 512:
> -        return ASPEED_SDMC_DRAM_512MB;
> -    default:
> -        g_assert_not_reached();
> -        break;
> -    }
> -}
> -
> -static int ast2500_rambits(AspeedSDMCState *s)
> -{
> -    switch (s->ram_size >> 20) {
> -    case 128:
> -        return ASPEED_SDMC_AST2500_128MB;
> -    case 256:
> -        return ASPEED_SDMC_AST2500_256MB;
> -    case 512:
> -        return ASPEED_SDMC_AST2500_512MB;
> -    case 1024:
> -        return ASPEED_SDMC_AST2500_1024MB;
> -    default:
> -        g_assert_not_reached();
> -        break;
> -    }
> -}
> -
> -static int ast2600_rambits(AspeedSDMCState *s)
> -{
> -    switch (s->ram_size >> 20) {
> -    case 256:
> -        return ASPEED_SDMC_AST2600_256MB;
> -    case 512:
> -        return ASPEED_SDMC_AST2600_512MB;
> -    case 1024:
> -        return ASPEED_SDMC_AST2600_1024MB;
> -    case 2048:
> -        return ASPEED_SDMC_AST2600_2048MB;
> -    default:
> -        g_assert_not_reached();
> -        break;
> -    }
> -}
> -
>  static void aspeed_sdmc_reset(DeviceState *dev)
>  {
>      AspeedSDMCState *s = ASPEED_SDMC(dev);
> @@ -324,10 +273,32 @@ static const TypeInfo aspeed_sdmc_info = {
>      .abstract   = true,
>  };
>
> +static int aspeed_sdmc_get_ram_bits(AspeedSDMCState *s)
> +{
> +    AspeedSDMCClass *asc = ASPEED_SDMC_GET_CLASS(s);
> +    int i;
> +
> +    /*
> +     * The bitfield value encoding the RAM size is the index of the
> +     * possible RAM size array
> +     */
> +    for (i = 0; asc->valid_ram_sizes[i]; i++) {
> +        if (s->ram_size == asc->valid_ram_sizes[i]) {
> +            return i;
> +        }
> +    }
> +
> +    /*
> +     * Invalid RAM sizes should have been excluded when setting the
> +     * SoC RAM size.
> +     */
> +    g_assert_not_reached();
> +}
> +
>  static uint32_t aspeed_2400_sdmc_compute_conf(AspeedSDMCState *s, uint32_t 
> data)
>  {
>      uint32_t fixed_conf = ASPEED_SDMC_VGA_COMPAT |
> -        ASPEED_SDMC_DRAM_SIZE(ast2400_rambits(s));
> +        ASPEED_SDMC_DRAM_SIZE(aspeed_sdmc_get_ram_bits(s));
>
>      /* Make sure readonly bits are kept */
>      data &= ~ASPEED_SDMC_READONLY_MASK;
> @@ -385,7 +356,7 @@ static uint32_t 
> aspeed_2500_sdmc_compute_conf(AspeedSDMCState *s, uint32_t data)
>      uint32_t fixed_conf = ASPEED_SDMC_HW_VERSION(1) |
>          ASPEED_SDMC_VGA_APERTURE(ASPEED_SDMC_VGA_64MB) |
>          ASPEED_SDMC_CACHE_INITIAL_DONE |
> -        ASPEED_SDMC_DRAM_SIZE(ast2500_rambits(s));
> +        ASPEED_SDMC_DRAM_SIZE(aspeed_sdmc_get_ram_bits(s));
>
>      /* Make sure readonly bits are kept */
>      data &= ~ASPEED_SDMC_AST2500_READONLY_MASK;
> @@ -451,7 +422,7 @@ static uint32_t 
> aspeed_2600_sdmc_compute_conf(AspeedSDMCState *s, uint32_t data)
>  {
>      uint32_t fixed_conf = ASPEED_SDMC_HW_VERSION(3) |
>          ASPEED_SDMC_VGA_APERTURE(ASPEED_SDMC_VGA_64MB) |
> -        ASPEED_SDMC_DRAM_SIZE(ast2600_rambits(s));
> +        ASPEED_SDMC_DRAM_SIZE(aspeed_sdmc_get_ram_bits(s));
>
>      /* Make sure readonly bits are kept (use ast2500 mask) */
>      data &= ~ASPEED_SDMC_AST2500_READONLY_MASK;
> --
> 2.25.4
>