On Mon, Aug 01, 2022 at 10:40:20PM +0800, Baoquan He wrote:
> This is a preparation patch, no functionality change.
There is, please see below.
> @@ -3,11 +3,17 @@
> #include <linux/mm.h>
> #include <linux/io.h>
>
> -void __iomem *ioremap_allowed(phys_addr_t phys_addr, size_t size, unsigned long prot)
> +void __iomem *
> +ioremap_allowed(phys_addr_t *paddr, size_t size, unsigned long *prot_val)
> {
> - unsigned long last_addr = phys_addr + size - 1;
> + unsigned long last_addr, offset, phys_addr = *paddr;
> int ret = -EINVAL;
>
> + offset = phys_addr & (~PAGE_MASK);
> + phys_addr -= offset;
FWIW, phys_addr &= PAGE_MASK looks much more usual.
> @@ -11,13 +11,20 @@
> #include <linux/io.h>
> #include <linux/export.h>
>
> -void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
> +void __iomem *ioremap_prot(phys_addr_t paddr, size_t size,
> unsigned long prot)
> {
> unsigned long offset, vaddr;
> - phys_addr_t last_addr;
> + phys_addr_t last_addr, phys_addr = paddr;
> struct vm_struct *area;
> void __iomem *base;
> + unsigned long prot_val = prot;
Why prot_val is needed?
> + base = ioremap_allowed(&phys_addr, size, &prot_val);
> + if (IS_ERR(base))
> + return NULL;
> + else if (base)
> + return base;
By moving ioremap_allowed() here you allow it to be called
before the wrap-around check, including architectures that
do not do fixups.
And now ioremap_allowed() semantics, prototype and name turn
less than obvious. Why not introduce a separate fixup callback?
> /* Disallow wrap-around or zero size */
> last_addr = phys_addr + size - 1;
> @@ -29,12 +36,6 @@ void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size,
> phys_addr -= offset;
> size = PAGE_ALIGN(size + offset);
>
> - base = ioremap_allowed(phys_addr, size, prot);
> - if (IS_ERR(base))
> - return NULL;
> - else if (base)
> - return base;
> -
> area = get_vm_area_caller(size, VM_IOREMAP,
> __builtin_return_address(0));
> if (!area)
