On Mon, Aug 01, 2022 at 10:40:19PM +0800, Baoquan He wrote:
Hi Baoquan,
> --- a/arch/arm64/mm/ioremap.c
> +++ b/arch/arm64/mm/ioremap.c
> @@ -3,19 +3,20 @@
> #include <linux/mm.h>
> #include <linux/io.h>
>
> -bool ioremap_allowed(phys_addr_t phys_addr, size_t size, unsigned long prot)
> +void __iomem *ioremap_allowed(phys_addr_t phys_addr, size_t size, unsigned long prot)
> {
> unsigned long last_addr = phys_addr + size - 1;
> + int ret = -EINVAL;
If ret variable is really needed?
> diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h
> index 72974cb81343..d72eb310fb3c 100644
> --- a/include/asm-generic/io.h
> +++ b/include/asm-generic/io.h
> @@ -967,26 +967,27 @@ static inline void iounmap(volatile void __iomem *addr)
> /*
> * Arch code can implement the following two hooks when using GENERIC_IOREMAP
> * ioremap_allowed() return a bool,
> - * - true means continue to remap
> - * - false means skip remap and return directly
> + * - IS_ERR means return an error
> + * - NULL means continue to remap
> + * - a non-NULL, non-IS_ERR pointer is returned directly
If ioremap_allowed() returns a valid pointer, then the function name
is not as precise anymore.
> @@ -28,8 +29,11 @@ void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
> phys_addr -= offset;
> size = PAGE_ALIGN(size + offset);
>
> - if (!ioremap_allowed(phys_addr, size, prot))
> + base = ioremap_allowed(phys_addr, size, prot);
> + if (IS_ERR(base))
> return NULL;
> + else if (base)
> + return base;
It is probably just me, but the base name bit misleading here.
> @@ -50,9 +54,9 @@ EXPORT_SYMBOL(ioremap_prot);
>
> void iounmap(volatile void __iomem *addr)
> {
> - void *vaddr = (void *)((unsigned long)addr & PAGE_MASK);
> + void __iomem *vaddr = (void __iomem *)((unsigned long)addr & PAGE_MASK);
>
> - if (!iounmap_allowed(vaddr))
> + if (iounmap_allowed(vaddr))
I guess, iounmap_allowed() should accept void __iomem *, not void *.
Then addr needs to be passed to iounmap_allowed() not vaddr.
> return;
