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_pud_supported(void);
  37 int arch_ioremap_pmd_supported(void);
  38 #else
  39 static inline void ioremap_huge_init(void) { }
  40 #endif
  41
  42 /*
  43  * Managed iomap interface
  44  */
  45 #ifdef CONFIG_HAS_IOPORT_MAP
  46 void __iomem * devm_ioport_map(struct device *dev, unsigned long port,
  47                                unsigned int nr);
  48 void devm_ioport_unmap(struct device *dev, void __iomem *addr);
  49 #else
  50 static inline void __iomem *devm_ioport_map(struct device *dev,
  51                                              unsigned long port,
  52                                              unsigned int nr)
  53 {
  54         return NULL;
  55 }
  56
  57 static 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
  64 void __iomem *devm_ioremap(struct device *dev, resource_size_t offset,
  65                            resource_size_t size);
  66 void __iomem *devm_ioremap_nocache(struct device *dev, resource_size_t offset,
  67                                    resource_size_t size);
  68 void __iomem *devm_ioremap_wc(struct device *dev, resource_size_t offset,
  69                                    resource_size_t size);
  70 void devm_iounmap(struct device *dev, void __iomem *addr);
  71 int check_signature(const volatile void __iomem *io_addr,
  72                         const unsigned char *signature, int length);
  73 void devm_ioremap_release(struct device *dev, void *res);
  74
  75 void *devm_memremap(struct device *dev, resource_size_t offset,
  76                 size_t size, unsigned long flags);
  77 void devm_memunmap(struct device *dev, void *addr);
  78
  79 void *__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
  94 static 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
 123 static 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
 129 static 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
 135 static 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
 143 enum {
 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
 152 void *memremap(resource_size_t offset, size_t size, unsigned long flags);
 153 void 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
 165 static inline int arch_io_reserve_memtype_wc(resource_size_t base,
 166                                              resource_size_t size)
 167 {
 168         return 0;
 169 }
 170
 171 static 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 */