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author | Christoph Hellwig <hch@lst.de> | 2019-08-11 14:53:20 +0200 |
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committer | Christoph Hellwig <hch@lst.de> | 2019-11-11 21:18:19 +0100 |
commit | 97c9801a15e5b0c9a20e495b2ccabf010894e74b (patch) | |
tree | 9c5e1f7c2b7d399de0493f9af5433f2e6b51381a | |
parent | e97133959ad2942ae43c81a08858bef01bc0ec18 (diff) | |
download | linux-97c9801a15e5b0c9a20e495b2ccabf010894e74b.tar.gz linux-97c9801a15e5b0c9a20e495b2ccabf010894e74b.tar.bz2 linux-97c9801a15e5b0c9a20e495b2ccabf010894e74b.zip |
asm-generic: don't provide ioremap for CONFIG_MMU
All MMU-enabled ports have a non-trivial ioremap and should thus provide
the prototype for their implementation instead of providing a generic
one unless a different symbol is not defined. Note that this only
affects sparc32 nds32 as all others do provide their own version.
Also update the kerneldoc comments in asm-generic/io.h to explain the
situation around the default ioremap* implementations correctly.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
-rw-r--r-- | arch/nds32/include/asm/io.h | 2 | ||||
-rw-r--r-- | arch/sparc/include/asm/io_32.h | 1 | ||||
-rw-r--r-- | include/asm-generic/io.h | 29 |
3 files changed, 11 insertions, 21 deletions
diff --git a/arch/nds32/include/asm/io.h b/arch/nds32/include/asm/io.h index 16f262322b8f..fb0e8a24c7af 100644 --- a/arch/nds32/include/asm/io.h +++ b/arch/nds32/include/asm/io.h @@ -6,6 +6,7 @@ #include <linux/types.h> +void __iomem *ioremap(phys_addr_t phys_addr, size_t size); extern void iounmap(volatile void __iomem *addr); #define __raw_writeb __raw_writeb static inline void __raw_writeb(u8 val, volatile void __iomem *addr) @@ -80,4 +81,5 @@ static inline u32 __raw_readl(const volatile void __iomem *addr) #define writew(v,c) ({ __iowmb(); writew_relaxed((v),(c)); }) #define writel(v,c) ({ __iowmb(); writel_relaxed((v),(c)); }) #include <asm-generic/io.h> + #endif /* __ASM_NDS32_IO_H */ diff --git a/arch/sparc/include/asm/io_32.h b/arch/sparc/include/asm/io_32.h index df2dc1784673..9a52d9506f80 100644 --- a/arch/sparc/include/asm/io_32.h +++ b/arch/sparc/include/asm/io_32.h @@ -127,6 +127,7 @@ static inline void sbus_memcpy_toio(volatile void __iomem *dst, * Bus number may be embedded in the higher bits of the physical address. * This is why we have no bus number argument to ioremap(). */ +void __iomem *ioremap(phys_addr_t offset, size_t size); void iounmap(volatile void __iomem *addr); /* Create a virtual mapping cookie for an IO port range */ void __iomem *ioport_map(unsigned long port, unsigned int nr); diff --git a/include/asm-generic/io.h b/include/asm-generic/io.h index bf8204de3a48..ed74d2e9af75 100644 --- a/include/asm-generic/io.h +++ b/include/asm-generic/io.h @@ -922,28 +922,16 @@ static inline void *phys_to_virt(unsigned long address) /** * DOC: ioremap() and ioremap_*() variants * - * If you have an IOMMU your architecture is expected to have both ioremap() - * and iounmap() implemented otherwise the asm-generic helpers will provide a - * direct mapping. + * 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. * - * There are ioremap_*() call variants, if you have no IOMMU we naturally will - * default to direct mapping for all of them, you can override these defaults. - * If you have an IOMMU you are highly encouraged to provide your own - * ioremap variant implementation as there currently is no safe architecture - * agnostic default. To avoid possible improper behaviour default asm-generic - * ioremap_*() variants all return NULL when an IOMMU is available. If you've - * defined your own ioremap_*() variant you must then declare your own - * ioremap_*() variant as defined to itself to avoid the default NULL return. + * ioremap_wc() and ioremap_wt() can provide more relaxed caching attributes + * for specific drivers if the architecture choses to implement them. If they + * are not implemented we fall back to plain ioremap. */ #ifndef CONFIG_MMU - -/* - * Change "struct page" to physical address. - * - * This implementation is for the no-MMU case only... if you have an MMU - * you'll need to provide your own definitions. - */ - #ifndef ioremap #define ioremap ioremap static inline void __iomem *ioremap(phys_addr_t offset, size_t size) @@ -954,14 +942,13 @@ static inline void __iomem *ioremap(phys_addr_t offset, size_t size) #ifndef iounmap #define iounmap iounmap - static inline void iounmap(void __iomem *addr) { } #endif #endif /* CONFIG_MMU */ + #ifndef ioremap_nocache -void __iomem *ioremap(phys_addr_t phys_addr, size_t size); #define ioremap_nocache ioremap_nocache static inline void __iomem *ioremap_nocache(phys_addr_t offset, size_t size) { |