92281dee82
Existing users of ioremap_cache() are mapping memory that is known in advance to not have i/o side effects. These users are forced to cast away the __iomem annotation, or otherwise neglect to fix the sparse errors thrown when dereferencing pointers to this memory. Provide memremap() as a non __iomem annotated ioremap_*() in the case when ioremap is otherwise a pointer to cacheable memory. Empirically, ioremap_<cacheable-type>() call sites are seeking memory-like semantics (e.g. speculative reads, and prefetching permitted). memremap() is a break from the ioremap implementation pattern of adding a new memremap_<type>() for each mapping type and having silent compatibility fall backs. Instead, the implementation defines flags that are passed to the central memremap() and if a mapping type is not supported by an arch memremap returns NULL. We introduce a memremap prototype as a trivial wrapper of ioremap_cache() and ioremap_wt(). Later, once all ioremap_cache() and ioremap_wt() usage has been removed from drivers we teach archs to implement arch_memremap() with the ability to strictly enforce the mapping type. Cc: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dan Williams <dan.j.williams@intel.com>
84 lines
1.8 KiB
C
84 lines
1.8 KiB
C
/*
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* include/asm-xtensa/io.h
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file "COPYING" in the main directory of this archive
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* for more details.
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*
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* Copyright (C) 2001 - 2005 Tensilica Inc.
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*/
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#ifndef _XTENSA_IO_H
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#define _XTENSA_IO_H
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#ifdef __KERNEL__
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#include <asm/byteorder.h>
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#include <asm/page.h>
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#include <asm/vectors.h>
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#include <linux/bug.h>
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#include <linux/kernel.h>
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#include <linux/types.h>
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#define IOADDR(x) (XCHAL_KIO_BYPASS_VADDR + (x))
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#define IO_SPACE_LIMIT ~0
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#ifdef CONFIG_MMU
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#if XCHAL_HAVE_PTP_MMU && XCHAL_HAVE_SPANNING_WAY && defined(CONFIG_OF)
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extern unsigned long xtensa_kio_paddr;
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static inline unsigned long xtensa_get_kio_paddr(void)
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{
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return xtensa_kio_paddr;
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}
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#endif
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/*
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* Return the virtual address for the specified bus memory.
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* Note that we currently don't support any address outside the KIO segment.
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*/
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static inline void __iomem *ioremap_nocache(unsigned long offset,
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unsigned long size)
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{
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if (offset >= XCHAL_KIO_PADDR
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&& offset - XCHAL_KIO_PADDR < XCHAL_KIO_SIZE)
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return (void*)(offset-XCHAL_KIO_PADDR+XCHAL_KIO_BYPASS_VADDR);
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else
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BUG();
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}
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static inline void __iomem *ioremap_cache(unsigned long offset,
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unsigned long size)
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{
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if (offset >= XCHAL_KIO_PADDR
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&& offset - XCHAL_KIO_PADDR < XCHAL_KIO_SIZE)
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return (void*)(offset-XCHAL_KIO_PADDR+XCHAL_KIO_CACHED_VADDR);
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else
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BUG();
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}
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#define ioremap_cache ioremap_cache
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#define ioremap_wc ioremap_nocache
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#define ioremap_wt ioremap_nocache
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static inline void __iomem *ioremap(unsigned long offset, unsigned long size)
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{
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return ioremap_nocache(offset, size);
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}
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static inline void iounmap(volatile void __iomem *addr)
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{
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}
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#define virt_to_bus virt_to_phys
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#define bus_to_virt phys_to_virt
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#endif /* CONFIG_MMU */
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#endif /* __KERNEL__ */
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#include <asm-generic/io.h>
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#endif /* _XTENSA_IO_H */
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