On 08/04/22 at 06:02pm, Alexander Gordeev wrote:
> 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.
Sure, will change.
>
> > @@ -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?
I will remove it and pass &prot to ioremap_allowed(). I could think too
much when I made change here. Thanks.
>
> > + 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.
Yes, just as you say.
>
> And now ioremap_allowed() semantics, prototype and name turn
> less than obvious. Why not introduce a separate fixup callback?
I can do that, while a little worried if too many hooks introduced.
I will introduce another fixup hook in v2 if no other suggestion or
concern. Thanks.
>
> > /* 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)
>
