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 #ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
  35 void __init ioremap_huge_init(void);
  36 int arch_ioremap_p4d_supported(void);
  37 int arch_ioremap_pud_supported(void);
  38 int arch_ioremap_pmd_supported(void);
  39 #else
  40 static inline void ioremap_huge_init(void) { }
  41 #endif
  42
  43 /*
  44  * Managed iomap interface
  45  */
  46 #ifdef CONFIG_HAS_IOPORT_MAP
  47 void __iomem * devm_ioport_map(struct device *dev, unsigned long port,
  48                                unsigned int nr);
  49 void devm_ioport_unmap(struct device *dev, void __iomem *addr);
  50 #else
  51 static inline void __iomem *devm_ioport_map(struct device *dev,
  52                                              unsigned long port,
  53                                              unsigned int nr)
  54 {
  55         return NULL;
  56 }
  57
  58 static 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
  65 void __iomem *devm_ioremap(struct device *dev, resource_size_t offset,
  66                            resource_size_t size);
  67 void __iomem *devm_ioremap_uc(struct device *dev, resource_size_t offset,
  68                                    resource_size_t size);
  69 void __iomem *devm_ioremap_wc(struct device *dev, resource_size_t offset,
  70                                    resource_size_t size);
  71 void devm_iounmap(struct device *dev, void __iomem *addr);
  72 int check_signature(const volatile void __iomem *io_addr,
  73                         const unsigned char *signature, int length);
  74 void devm_ioremap_release(struct device *dev, void *res);
  75
  76 void *devm_memremap(struct device *dev, resource_size_t offset,
  77                 size_t size, unsigned long flags);
  78 void 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
  93 static 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
 122 static 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
 128 static 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
 134 static 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
 142 enum {
 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
 151 void *memremap(resource_size_t offset, size_t size, unsigned long flags);
 152 void 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
 164 static inline int arch_io_reserve_memtype_wc(resource_size_t base,
 165                                              resource_size_t size)
 166 {
 167         return 0;
 168 }
 169
 170 static 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 */