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_p4d_supported(void);
  37int arch_ioremap_pud_supported(void);
  38int arch_ioremap_pmd_supported(void);
  39#else
  40static inline void ioremap_huge_init(void) { }
  41#endif
  42
  43/*
  44 * Managed iomap interface
  45 */
  46#ifdef CONFIG_HAS_IOPORT_MAP
  47void __iomem * devm_ioport_map(struct device *dev, unsigned long port,
  48                               unsigned int nr);
  49void devm_ioport_unmap(struct device *dev, void __iomem *addr);
  50#else
  51static inline void __iomem *devm_ioport_map(struct device *dev,
  52                                             unsigned long port,
  53                                             unsigned int nr)
  54{
  55        return NULL;
  56}
  57
  58static inline void devm_ioport_unmap(struct device *dev, void __iomem *addr)
  59{
  60}
  61#endif
  62
  63#define IOMEM_ERR_PTR(err) (__force void __iomem *)ERR_PTR(err)
  64
  65void __iomem *devm_ioremap(struct device *dev, resource_size_t offset,
  66                           resource_size_t size);
  67void __iomem *devm_ioremap_uc(struct device *dev, resource_size_t offset,
  68                                   resource_size_t size);
  69void __iomem *devm_ioremap_wc(struct device *dev, resource_size_t offset,
  70                                   resource_size_t size);
  71void devm_iounmap(struct device *dev, void __iomem *addr);
  72int check_signature(const volatile void __iomem *io_addr,
  73                        const unsigned char *signature, int length);
  74void devm_ioremap_release(struct device *dev, void *res);
  75
  76void *devm_memremap(struct device *dev, resource_size_t offset,
  77                size_t size, unsigned long flags);
  78void devm_memunmap(struct device *dev, void *addr);
  79
  80#ifdef CONFIG_PCI
  81/*
  82 * The PCI specifications (Rev 3.0, 3.2.5 "Transaction Ordering and
  83 * Posting") mandate non-posted configuration transactions. There is
  84 * no ioremap API in the kernel that can guarantee non-posted write
  85 * semantics across arches so provide a default implementation for
  86 * mapping PCI config space that defaults to ioremap(); arches
  87 * should override it if they have memory mapping implementations that
  88 * guarantee non-posted writes semantics to make the memory mapping
  89 * compliant with the PCI specification.
  90 */
  91#ifndef pci_remap_cfgspace
  92#define pci_remap_cfgspace pci_remap_cfgspace
  93static inline void __iomem *pci_remap_cfgspace(phys_addr_t offset,
  94                                               size_t size)
  95{
  96        return ioremap(offset, size);
  97}
  98#endif
  99#endif
 100
 101/*
 102 * Some systems do not have legacy ISA devices.
 103 * /dev/port is not a valid interface on these systems.
 104 * So for those archs, <asm/io.h> should define the following symbol.
 105 */
 106#ifndef arch_has_dev_port
 107#define arch_has_dev_port()     (1)
 108#endif
 109
 110/*
 111 * Some systems (x86 without PAT) have a somewhat reliable way to mark a
 112 * physical address range such that uncached mappings will actually
 113 * end up write-combining.  This facility should be used in conjunction
 114 * with pgprot_writecombine, ioremap-wc, or set_memory_wc, since it has
 115 * no effect if the per-page mechanisms are functional.
 116 * (On x86 without PAT, these functions manipulate MTRRs.)
 117 *
 118 * arch_phys_del_wc(0) or arch_phys_del_wc(any error code) is guaranteed
 119 * to have no effect.
 120 */
 121#ifndef arch_phys_wc_add
 122static inline int __must_check arch_phys_wc_add(unsigned long base,
 123                                                unsigned long size)
 124{
 125        return 0;  /* It worked (i.e. did nothing). */
 126}
 127
 128static inline void arch_phys_wc_del(int handle)
 129{
 130}
 131
 132#define arch_phys_wc_add arch_phys_wc_add
 133#ifndef arch_phys_wc_index
 134static inline int arch_phys_wc_index(int handle)
 135{
 136        return -1;
 137}
 138#define arch_phys_wc_index arch_phys_wc_index
 139#endif
 140#endif
 141
 142enum {
 143        /* See memremap() kernel-doc for usage description... */
 144        MEMREMAP_WB = 1 << 0,
 145        MEMREMAP_WT = 1 << 1,
 146        MEMREMAP_WC = 1 << 2,
 147        MEMREMAP_ENC = 1 << 3,
 148        MEMREMAP_DEC = 1 << 4,
 149};
 150
 151void *memremap(resource_size_t offset, size_t size, unsigned long flags);
 152void memunmap(void *addr);
 153
 154/*
 155 * On x86 PAT systems we have memory tracking that keeps track of
 156 * the allowed mappings on memory ranges. This tracking works for
 157 * all the in-kernel mapping APIs (ioremap*), but where the user
 158 * wishes to map a range from a physical device into user memory
 159 * the tracking won't be updated. This API is to be used by
 160 * drivers which remap physical device pages into userspace,
 161 * and wants to make sure they are mapped WC and not UC.
 162 */
 163#ifndef arch_io_reserve_memtype_wc
 164static inline int arch_io_reserve_memtype_wc(resource_size_t base,
 165                                             resource_size_t size)
 166{
 167        return 0;
 168}
 169
 170static inline void arch_io_free_memtype_wc(resource_size_t base,
 171                                           resource_size_t size)
 172{
 173}
 174#endif
 175
 176#endif /* _LINUX_IO_H */
 177