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

[Dong, Eddie]

> 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

The root cause is that ASPEED_WDT_REGS_MAX is too small, right?
Probably the Qemu is emulating an old version of the hardware.

Given the meaning of ASPEED_WDT_REGS_MAX, it should be larger than iosize, not?
Probably ASPEED_WDT_REGS_MAX should be per device type (aspeed_2400/2500),
while iosize is for all devices, and its initial value comes from the per 
device type REGS_MAX.

> 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.
> 
> [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);
>  }
> 
> --
> 2.38.1
>