Re: [PATCH v2 02/11] hw/watchdog/wdt_aspeed: Extend MMIO range to cover more registers

[Philippe Mathieu-Daudé]

On 30/12/22 12:34, Philippe Mathieu-Daudé wrote:
> When booting the Zephyr demo in [1] we get:
>
>    aspeed.io: unimplemented device write (size 4, offset 0x185128, value 
> 0x030f1ff1) <--
>    aspeed.io: unimplemented device write (size 4, offset 0x18512c, value 
> 0x03fffff1)
>
> This corresponds to this Zephyr code [2]:
>
>    static int aspeed_wdt_init(const struct device *dev)
>    {
>      const struct aspeed_wdt_config *config = dev->config;
>      struct aspeed_wdt_data *const data = dev->data;
>      uint32_t reg_val;
>
>      /* disable WDT by default */
>      reg_val = sys_read32(config->ctrl_base + WDT_CTRL_REG);
>      reg_val &= ~WDT_CTRL_ENABLE;
>      sys_write32(reg_val, config->ctrl_base + WDT_CTRL_REG);
>
>      sys_write32(data->rst_mask1,
>                  config->ctrl_base + WDT_SW_RESET_MASK1_REG);   <------
>      sys_write32(data->rst_mask2,
>                  config->ctrl_base + WDT_SW_RESET_MASK2_REG);
>
>      return 0;
>    }
>
> The register definitions are [3]:
>
>    #define WDT_RELOAD_VAL_REG          0x0004
>    #define WDT_RESTART_REG             0x0008
>    #define WDT_CTRL_REG                0x000C
>    #define WDT_TIMEOUT_STATUS_REG      0x0010
>    #define WDT_TIMEOUT_STATUS_CLR_REG  0x0014
>    #define WDT_RESET_MASK1_REG         0x001C
>    #define WDT_RESET_MASK2_REG         0x0020
>    #define WDT_SW_RESET_MASK1_REG      0x0028   <------
>    #define WDT_SW_RESET_MASK2_REG      0x002C
>    #define WDT_SW_RESET_CTRL_REG       0x0024
>
> Currently QEMU only cover a MMIO region of size 0x20:
>
>    #define ASPEED_WDT_REGS_MAX        (0x20 / 4)
>
> Change to map the whole 'iosize' which might be bigger, covering
> the other registers. The MemoryRegionOps read/write handlers will
> report the accesses as out-of-bounds guest-errors, but the next
> commit will report them as unimplemented.

I'll amend here for clarity:

---

Memory layout before this change:

  (qemu) info mtree -f
    ...
    000000007e785000-000000007e78501f (prio 0, i/o): aspeed.wdt
    000000007e785020-000000007e78507f (prio -1000, i/o): aspeed.io 
@0000000000185020
    000000007e785080-000000007e78509f (prio 0, i/o): aspeed.wdt
    000000007e7850a0-000000007e7850ff (prio -1000, i/o): aspeed.io 
@00000000001850a0
    000000007e785100-000000007e78511f (prio 0, i/o): aspeed.wdt
    000000007e785120-000000007e78517f (prio -1000, i/o): aspeed.io 
@0000000000185120
    000000007e785180-000000007e78519f (prio 0, i/o): aspeed.wdt
    000000007e7851a0-000000007e788fff (prio -1000, i/o): aspeed.io 
@00000000001851a0

After:

  (qemu) info mtree -f
    ...
    000000007e785000-000000007e78507f (prio 0, i/o): aspeed.wdt
    000000007e785080-000000007e7850ff (prio 0, i/o): aspeed.wdt
    000000007e785100-000000007e78517f (prio 0, i/o): aspeed.wdt
    000000007e785180-000000007e7851ff (prio 0, i/o): aspeed.wdt
    000000007e785200-000000007e788fff (prio -1000, i/o): aspeed.io 
@0000000000185200
---

> [1] https://github.com/AspeedTech-BMC/zephyr/releases/tag/v00.01.07
> [2] https://github.com/AspeedTech-BMC/zephyr/commit/2e99f10ac27b
> [3] 
> https://github.com/AspeedTech-BMC/zephyr/blob/v00.01.08/drivers/watchdog/wdt_aspeed.c#L31
>
> Reviewed-by: Peter Delevoryas <peter@pjd.dev>
> Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> ---
>   hw/watchdog/wdt_aspeed.c | 3 ++-
>   1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/hw/watchdog/wdt_aspeed.c b/hw/watchdog/wdt_aspeed.c
> index 958725a1b5..eefca31ae4 100644
> --- a/hw/watchdog/wdt_aspeed.c
> +++ b/hw/watchdog/wdt_aspeed.c
> @@ -260,6 +260,7 @@ static void aspeed_wdt_realize(DeviceState *dev, Error 
> **errp)
>   {
>       SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
>       AspeedWDTState *s = ASPEED_WDT(dev);
> +    AspeedWDTClass *awc = ASPEED_WDT_GET_CLASS(dev);
>   
>       assert(s->scu);
>   
> @@ -271,7 +272,7 @@ static void aspeed_wdt_realize(DeviceState *dev, Error **errp)
>       s->pclk_freq = PCLK_HZ;
>   
>       memory_region_init_io(&s->iomem, OBJECT(s), &aspeed_wdt_ops, s,
> -                          TYPE_ASPEED_WDT, ASPEED_WDT_REGS_MAX * 4);
> +                          TYPE_ASPEED_WDT, awc->iosize);
>       sysbus_init_mmio(sbd, &s->iomem);
>   }
>