Re: [XEN v4 05/11] xen/arm: Introduce a wrapper for dt_device_get_address() to handle paddr_t

[Julien Grall <julien@xxxxxxx>]

Hi Ayan,

On 21/03/2023 14:03, Ayan Kumar Halder wrote:
> dt_device_get_address() can accept uint64_t only for address and size.
> However, the address/size denotes physical addresses. Thus, they should
> be represented by 'paddr_t'.
> Consequently, we introduce a wrapper for dt_device_get_address() ie
> dt_device_get_paddr() which accepts address/size as paddr_t and inturn
> invokes dt_device_get_address() after converting address/size to
> uint64_t.
>
> The reason for introducing doing this is that in future 'paddr_t' may
> be defined as uint32_t.
Technically, you will define it as 'unsigned long' after. To avoid 
relying on how paddr_t is defined, I would suggest ot write "'paddr_t' 
may not always be 64-bit" or similar.
> diff --git a/xen/arch/arm/platforms/brcm-raspberry-pi.c 
> b/xen/arch/arm/platforms/brcm-raspberry-pi.c
> index 811b40b1a6..407ec07f63 100644
> --- a/xen/arch/arm/platforms/brcm-raspberry-pi.c
> +++ b/xen/arch/arm/platforms/brcm-raspberry-pi.c
> @@ -64,7 +64,7 @@ static void __iomem *rpi4_map_watchdog(void)
>       if ( !node )
>           return NULL;
>   
> -    ret = dt_device_get_address(node, 0, &start, &len);
> +    ret = dt_device_get_paddr(node, 0, &start, &len);
>       if ( ret )
>       {
>           printk("Cannot read watchdog register address\n");
> diff --git a/xen/arch/arm/platforms/brcm.c b/xen/arch/arm/platforms/brcm.c
> index d481b2c60f..4310feee73 100644
> --- a/xen/arch/arm/platforms/brcm.c
> +++ b/xen/arch/arm/platforms/brcm.c
> @@ -40,7 +40,7 @@ static __init int brcm_get_dt_node(char *compat_str,
>                                      u32 *reg_base)
>   {
>       const struct dt_device_node *node;
> -    u64 reg_base_64;
> +    paddr_t reg_base_64;
'64' reads a bit odd now. I think you want to rename to reg_base_paddr.

Cheers,

--
Julien Grall