include/linux/io.h

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