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. > > > @@ -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? I finally renamed ioremap_allowed()/iounmap_allowed() to arch_ioremap() and arch_iounmap(). I didn't introduce a separate fixup callback, and have added more explanation to log of patch 1~2, please check that.