linux/include/linux/io.h
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   1/* SPDX-License-Identifier: GPL-2.0-only */
   2/*
   3 * Copyright 2006 PathScale, Inc.  All Rights Reserved.
   4 */
   5
   6#ifndef _LINUX_IO_H
   7#define _LINUX_IO_H
   8
   9#include <linux/types.h>
  10#include <linux/init.h>
  11#include <linux/bug.h>
  12#include <linux/err.h>
  13#include <asm/io.h>
  14#include <asm/page.h>
  15
  16struct device;
  17struct resource;
  18
  19__visible void __iowrite32_copy(void __iomem *to, const void *from, size_t count);
  20void __ioread32_copy(void *to, const void __iomem *from, size_t count);
  21void __iowrite64_copy(void __iomem *to, const void *from, size_t count);
  22
  23#ifdef CONFIG_MMU
  24int ioremap_page_range(unsigned long addr, unsigned long end,
  25                       phys_addr_t phys_addr, pgprot_t prot);
  26#else
  27static inline int ioremap_page_range(unsigned long addr, unsigned long end,
  28                                     phys_addr_t phys_addr, pgprot_t prot)
  29{
  30        return 0;
  31}
  32#endif
  33
  34#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
  35void __init ioremap_huge_init(void);
  36int arch_ioremap_pud_supported(void);
  37int arch_ioremap_pmd_supported(void);
  38#else
  39static inline void ioremap_huge_init(void) { }
  40#endif
  41
  42/*
  43 * Managed iomap interface
  44 */
  45#ifdef CONFIG_HAS_IOPORT_MAP
  46void __iomem * devm_ioport_map(struct device *dev, unsigned long port,
  47                               unsigned int nr);
  48void devm_ioport_unmap(struct device *dev, void __iomem *addr);
  49#else
  50static inline void __iomem *devm_ioport_map(struct device *dev,
  51                                             unsigned long port,
  52                                             unsigned int nr)
  53{
  54        return NULL;
  55}
  56
  57static inline void devm_ioport_unmap(struct device *dev, void __iomem *addr)
  58{
  59}
  60#endif
  61
  62#define IOMEM_ERR_PTR(err) (__force void __iomem *)ERR_PTR(err)
  63
  64void __iomem *devm_ioremap(struct device *dev, resource_size_t offset,
  65                           resource_size_t size);
  66void __iomem *devm_ioremap_nocache(struct device *dev, resource_size_t offset,
  67                                   resource_size_t size);
  68void __iomem *devm_ioremap_wc(struct device *dev, resource_size_t offset,
  69                                   resource_size_t size);
  70void devm_iounmap(struct device *dev, void __iomem *addr);
  71int check_signature(const volatile void __iomem *io_addr,
  72                        const unsigned char *signature, int length);
  73void devm_ioremap_release(struct device *dev, void *res);
  74
  75void *devm_memremap(struct device *dev, resource_size_t offset,
  76                size_t size, unsigned long flags);
  77void devm_memunmap(struct device *dev, void *addr);
  78
  79void *__devm_memremap_pages(struct device *dev, struct resource *res);
  80
  81#ifdef CONFIG_PCI
  82/*
  83 * The PCI specifications (Rev 3.0, 3.2.5 "Transaction Ordering and
  84 * Posting") mandate non-posted configuration transactions. There is
  85 * no ioremap API in the kernel that can guarantee non-posted write
  86 * semantics across arches so provide a default implementation for
  87 * mapping PCI config space that defaults to ioremap_nocache(); arches
  88 * should override it if they have memory mapping implementations that
  89 * guarantee non-posted writes semantics to make the memory mapping
  90 * compliant with the PCI specification.
  91 */
  92#ifndef pci_remap_cfgspace
  93#define pci_remap_cfgspace pci_remap_cfgspace
  94static inline void __iomem *pci_remap_cfgspace(phys_addr_t offset,
  95                                               size_t size)
  96{
  97        return ioremap_nocache(offset, size);
  98}
  99#endif
 100#endif
 101
 102/*
 103 * Some systems do not have legacy ISA devices.
 104 * /dev/port is not a valid interface on these systems.
 105 * So for those archs, <asm/io.h> should define the following symbol.
 106 */
 107#ifndef arch_has_dev_port
 108#define arch_has_dev_port()     (1)
 109#endif
 110
 111/*
 112 * Some systems (x86 without PAT) have a somewhat reliable way to mark a
 113 * physical address range such that uncached mappings will actually
 114 * end up write-combining.  This facility should be used in conjunction
 115 * with pgprot_writecombine, ioremap-wc, or set_memory_wc, since it has
 116 * no effect if the per-page mechanisms are functional.
 117 * (On x86 without PAT, these functions manipulate MTRRs.)
 118 *
 119 * arch_phys_del_wc(0) or arch_phys_del_wc(any error code) is guaranteed
 120 * to have no effect.
 121 */
 122#ifndef arch_phys_wc_add
 123static inline int __must_check arch_phys_wc_add(unsigned long base,
 124                                                unsigned long size)
 125{
 126        return 0;  /* It worked (i.e. did nothing). */
 127}
 128
 129static inline void arch_phys_wc_del(int handle)
 130{
 131}
 132
 133#define arch_phys_wc_add arch_phys_wc_add
 134#ifndef arch_phys_wc_index
 135static inline int arch_phys_wc_index(int handle)
 136{
 137        return -1;
 138}
 139#define arch_phys_wc_index arch_phys_wc_index
 140#endif
 141#endif
 142
 143enum {
 144        /* See memremap() kernel-doc for usage description... */
 145        MEMREMAP_WB = 1 << 0,
 146        MEMREMAP_WT = 1 << 1,
 147        MEMREMAP_WC = 1 << 2,
 148        MEMREMAP_ENC = 1 << 3,
 149        MEMREMAP_DEC = 1 << 4,
 150};
 151
 152void *memremap(resource_size_t offset, size_t size, unsigned long flags);
 153void memunmap(void *addr);
 154
 155/*
 156 * On x86 PAT systems we have memory tracking that keeps track of
 157 * the allowed mappings on memory ranges. This tracking works for
 158 * all the in-kernel mapping APIs (ioremap*), but where the user
 159 * wishes to map a range from a physical device into user memory
 160 * the tracking won't be updated. This API is to be used by
 161 * drivers which remap physical device pages into userspace,
 162 * and wants to make sure they are mapped WC and not UC.
 163 */
 164#ifndef arch_io_reserve_memtype_wc
 165static inline int arch_io_reserve_memtype_wc(resource_size_t base,
 166                                             resource_size_t size)
 167{
 168        return 0;
 169}
 170
 171static inline void arch_io_free_memtype_wc(resource_size_t base,
 172                                           resource_size_t size)
 173{
 174}
 175#endif
 176
 177#endif /* _LINUX_IO_H */
 178