From 80b0ca98f91ddbc09828aff5a00af1c73837713e Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 13 Aug 2019 11:24:04 +0200 Subject: lib: provide a simple generic ioremap implementation A lot of architectures reuse the same simple ioremap implementation, so start lifting the most simple variant to lib/ioremap.c. It provides ioremap_prot and iounmap, plus a default ioremap that uses prot_noncached, although that can be overridden by asm/io.h. Signed-off-by: Christoph Hellwig Reviewed-by: Arnd Bergmann Reviewed-by: Palmer Dabbelt --- include/asm-generic/io.h | 20 ++++++++++++++++---- lib/Kconfig | 3 +++ lib/ioremap.c | 39 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 58 insertions(+), 4 deletions(-) diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h index bd676f21b5bd..325fc98cc9ff 100644 --- a/include/asm-generic/io.h +++ b/include/asm-generic/io.h @@ -923,9 +923,10 @@ static inline void *phys_to_virt(unsigned long address) * DOC: ioremap() and ioremap_*() variants * * Architectures with an MMU are expected to provide ioremap() and iounmap() - * themselves. For NOMMU architectures we provide a default nop-op - * implementation that expect that the physical address used for MMIO are - * already marked as uncached, and can be used as kernel virtual addresses. + * themselves or rely on GENERIC_IOREMAP. For NOMMU architectures we provide + * a default nop-op implementation that expect that the physical address used + * for MMIO are already marked as uncached, and can be used as kernel virtual + * addresses. * * ioremap_wc() and ioremap_wt() can provide more relaxed caching attributes * for specific drivers if the architecture choses to implement them. If they @@ -946,7 +947,18 @@ static inline void iounmap(void __iomem *addr) { } #endif -#endif /* CONFIG_MMU */ +#elif defined(CONFIG_GENERIC_IOREMAP) +#include + +void __iomem *ioremap_prot(phys_addr_t addr, size_t size, unsigned long prot); +void iounmap(volatile void __iomem *addr); + +static inline void __iomem *ioremap(phys_addr_t addr, size_t size) +{ + /* _PAGE_IOREMAP needs to be supplied by the architecture */ + return ioremap_prot(addr, size, _PAGE_IOREMAP); +} +#endif /* !CONFIG_MMU || CONFIG_GENERIC_IOREMAP */ #ifndef ioremap_nocache #define ioremap_nocache ioremap diff --git a/lib/Kconfig b/lib/Kconfig index 3321d04dfa5a..cb571767d080 100644 --- a/lib/Kconfig +++ b/lib/Kconfig @@ -637,6 +637,9 @@ config STRING_SELFTEST endmenu +config GENERIC_IOREMAP + bool + config GENERIC_LIB_ASHLDI3 bool diff --git a/lib/ioremap.c b/lib/ioremap.c index 0a2ffadc6d71..3f0e18543de8 100644 --- a/lib/ioremap.c +++ b/lib/ioremap.c @@ -231,3 +231,42 @@ int ioremap_page_range(unsigned long addr, return err; } + +#ifdef CONFIG_GENERIC_IOREMAP +void __iomem *ioremap_prot(phys_addr_t addr, size_t size, unsigned long prot) +{ + unsigned long offset, vaddr; + phys_addr_t last_addr; + struct vm_struct *area; + + /* Disallow wrap-around or zero size */ + last_addr = addr + size - 1; + if (!size || last_addr < addr) + return NULL; + + /* Page-align mappings */ + offset = addr & (~PAGE_MASK); + addr -= offset; + size = PAGE_ALIGN(size + offset); + + area = get_vm_area_caller(size, VM_IOREMAP, + __builtin_return_address(0)); + if (!area) + return NULL; + vaddr = (unsigned long)area->addr; + + if (ioremap_page_range(vaddr, vaddr + size, addr, __pgprot(prot))) { + free_vm_area(area); + return NULL; + } + + return (void __iomem *)(vaddr + offset); +} +EXPORT_SYMBOL(ioremap_prot); + +void iounmap(volatile void __iomem *addr) +{ + vunmap((void *)((unsigned long)addr & PAGE_MASK)); +} +EXPORT_SYMBOL(iounmap); +#endif /* CONFIG_GENERIC_IOREMAP */ -- cgit v1.2.3