Messages in this thread | | | Date | Tue, 7 Jun 2022 15:37:10 +0800 | Subject | Re: [PATCH v4 4/6] mm: ioremap: Add ioremap/iounmap_allowed() | From | Kefeng Wang <> |
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On 2022/6/6 23:14, Baoquan He wrote: > On 06/06/22 at 03:48pm, Kefeng Wang wrote: >> Add special hook for architecture to verify addr, size or prot >> when ioremap() or iounmap(), which will make the generic ioremap >> more useful. >> >> ioremap_allowed() return an int, >> - NULL means continue to remap >> - error code means skip remap and return directly >> iounmap_allowed() return an int, >> - 0 means continue to vunmap >> - error code means skip vunmap and return directly > Aren't they bool type function and better return bool value?
Ok, let's keep it simple, back to v1's version , use bool, if we want to extend
them, do it later.
> >> Acked-by: Andrew Morton <akpm@linux-foundation.org> >> Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> >> --- >> include/asm-generic/io.h | 25 +++++++++++++++++++++++++ >> mm/ioremap.c | 13 ++++++++++--- >> 2 files changed, 35 insertions(+), 3 deletions(-) >> >> diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h >> index e6ffa2519f08..9429387a3e65 100644 >> --- a/include/asm-generic/io.h >> +++ b/include/asm-generic/io.h >> @@ -964,6 +964,31 @@ static inline void iounmap(volatile void __iomem *addr) >> #elif defined(CONFIG_GENERIC_IOREMAP) >> #include <linux/pgtable.h> >> >> +/* >> + * Arch code can implement the following two special hooks when using GENERIC_IOREMAP >> + * ioremap_allowed() return an int, >> + * - 0 means continue to remap >> + * - error code means skip remap and return directly >> + * iounmap_allowed() return an int, >> + * - 0 means continue to vunmap >> + * - error code means skip vunmap and return directly >> + */ >> +#ifndef ioremap_allowed >> +#define ioremap_allowed ioremap_allowed >> +static inline int ioremap_allowed(phys_addr_t phys_addr, size_t size, unsigned long prot) >> +{ >> + return 0; >> +} >> +#endif >> + >> +#ifndef iounmap_allowed >> +#define iounmap_allowed iounmap_allowed >> +static inline int iounmap_allowed(void __iomem *addr) >> +{ >> + return 0; >> +} >> +#endif >> + >> void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size, unsigned long prot); >> void iounmap(volatile void __iomem *addr); >> >> diff --git a/mm/ioremap.c b/mm/ioremap.c >> index 7cb9996b0c12..196c93c0beb8 100644 >> --- a/mm/ioremap.c >> +++ b/mm/ioremap.c >> @@ -27,8 +27,10 @@ void __iomem *ioremap_prot(phys_addr_t phys_addr, size_t size, unsigned long pro >> phys_addr -= offset; >> size = PAGE_ALIGN(size + offset); >> >> - area = get_vm_area_caller(size, VM_IOREMAP, >> - __builtin_return_address(0)); >> + if (ioremap_allowed(phys_addr, size, prot)) >> + return NULL; >> + >> + area = get_vm_area_caller(size, VM_IOREMAP, __builtin_return_address(0)); >> if (!area) >> return NULL; >> vaddr = (unsigned long)area->addr; >> @@ -45,6 +47,11 @@ EXPORT_SYMBOL(ioremap_prot); >> >> void iounmap(volatile void __iomem *addr) >> { >> - vunmap((void *)((unsigned long)addr & PAGE_MASK)); >> + void __iomem *vaddr = (void __iomem *)((unsigned long)addr & PAGE_MASK); >> + >> + if (iounmap_allowed(vaddr)) >> + return; >> + >> + vunmap((void __force *)vaddr); >> } >> EXPORT_SYMBOL(iounmap); >> -- >> 2.35.3 >> >> > .
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