1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Implement the default iomap interfaces 4 * 5 * (C) Copyright 2004 Linus Torvalds 6 */ 7 #include <linux/pci.h> 8 #include <linux/io.h> 9 10 #include <linux/export.h> 11 12 /** 13 * pci_iomap_range - create a virtual mapping cookie for a PCI BAR 14 * @dev: PCI device that owns the BAR 15 * @bar: BAR number 16 * @offset: map memory at the given offset in BAR 17 * @maxlen: max length of the memory to map 18 * 19 * Using this function you will get a __iomem address to your device BAR. 20 * You can access it using ioread*() and iowrite*(). These functions hide 21 * the details if this is a MMIO or PIO address space and will just do what 22 * you expect from them in the correct way. 23 * 24 * @maxlen specifies the maximum length to map. If you want to get access to 25 * the complete BAR from offset to the end, pass %0 here. 26 * 27 * NOTE: 28 * This function is never managed, even if you initialized with 29 * pcim_enable_device(). 30 * */ 31 void __iomem *pci_iomap_range(struct pci_dev *dev, 32 int bar, 33 unsigned long offset, 34 unsigned long maxlen) 35 { 36 resource_size_t start = pci_resource_start(dev, bar); 37 resource_size_t len = pci_resource_len(dev, bar); 38 unsigned long flags = pci_resource_flags(dev, bar); 39 40 if (len <= offset || !start) 41 return NULL; 42 len -= offset; 43 start += offset; 44 if (maxlen && len > maxlen) 45 len = maxlen; 46 if (flags & IORESOURCE_IO) 47 return __pci_ioport_map(dev, start, len); 48 if (flags & IORESOURCE_MEM) 49 return ioremap(start, len); 50 /* What? */ 51 return NULL; 52 } 53 EXPORT_SYMBOL(pci_iomap_range); 54 55 /** 56 * pci_iomap_wc_range - create a virtual WC mapping cookie for a PCI BAR 57 * @dev: PCI device that owns the BAR 58 * @bar: BAR number 59 * @offset: map memory at the given offset in BAR 60 * @maxlen: max length of the memory to map 61 * 62 * Using this function you will get a __iomem address to your device BAR. 63 * You can access it using ioread*() and iowrite*(). These functions hide 64 * the details if this is a MMIO or PIO address space and will just do what 65 * you expect from them in the correct way. When possible write combining 66 * is used. 67 * 68 * @maxlen specifies the maximum length to map. If you want to get access to 69 * the complete BAR from offset to the end, pass %0 here. 70 * 71 * NOTE: 72 * This function is never managed, even if you initialized with 73 * pcim_enable_device(). 74 * */ 75 void __iomem *pci_iomap_wc_range(struct pci_dev *dev, 76 int bar, 77 unsigned long offset, 78 unsigned long maxlen) 79 { 80 resource_size_t start = pci_resource_start(dev, bar); 81 resource_size_t len = pci_resource_len(dev, bar); 82 unsigned long flags = pci_resource_flags(dev, bar); 83 84 85 if (flags & IORESOURCE_IO) 86 return NULL; 87 88 if (len <= offset || !start) 89 return NULL; 90 91 len -= offset; 92 start += offset; 93 if (maxlen && len > maxlen) 94 len = maxlen; 95 96 if (flags & IORESOURCE_MEM) 97 return ioremap_wc(start, len); 98 99 /* What? */ 100 return NULL; 101 } 102 EXPORT_SYMBOL_GPL(pci_iomap_wc_range); 103 104 /** 105 * pci_iomap - create a virtual mapping cookie for a PCI BAR 106 * @dev: PCI device that owns the BAR 107 * @bar: BAR number 108 * @maxlen: length of the memory to map 109 * 110 * Using this function you will get a __iomem address to your device BAR. 111 * You can access it using ioread*() and iowrite*(). These functions hide 112 * the details if this is a MMIO or PIO address space and will just do what 113 * you expect from them in the correct way. 114 * 115 * @maxlen specifies the maximum length to map. If you want to get access to 116 * the complete BAR without checking for its length first, pass %0 here. 117 * 118 * NOTE: 119 * This function is never managed, even if you initialized with 120 * pcim_enable_device(). If you need automatic cleanup, use pcim_iomap(). 121 * */ 122 void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen) 123 { 124 return pci_iomap_range(dev, bar, 0, maxlen); 125 } 126 EXPORT_SYMBOL(pci_iomap); 127 128 /** 129 * pci_iomap_wc - create a virtual WC mapping cookie for a PCI BAR 130 * @dev: PCI device that owns the BAR 131 * @bar: BAR number 132 * @maxlen: length of the memory to map 133 * 134 * Using this function you will get a __iomem address to your device BAR. 135 * You can access it using ioread*() and iowrite*(). These functions hide 136 * the details if this is a MMIO or PIO address space and will just do what 137 * you expect from them in the correct way. When possible write combining 138 * is used. 139 * 140 * @maxlen specifies the maximum length to map. If you want to get access to 141 * the complete BAR without checking for its length first, pass %0 here. 142 * 143 * NOTE: 144 * This function is never managed, even if you initialized with 145 * pcim_enable_device(). 146 * */ 147 void __iomem *pci_iomap_wc(struct pci_dev *dev, int bar, unsigned long maxlen) 148 { 149 return pci_iomap_wc_range(dev, bar, 0, maxlen); 150 } 151 EXPORT_SYMBOL_GPL(pci_iomap_wc); 152 153 /* 154 * pci_iounmap() somewhat illogically comes from lib/iomap.c for the 155 * CONFIG_GENERIC_IOMAP case, because that's the code that knows about 156 * the different IOMAP ranges. 157 * 158 * But if the architecture does not use the generic iomap code, and if 159 * it has _not_ defined it's own private pci_iounmap function, we define 160 * it here. 161 * 162 * NOTE! This default implementation assumes that if the architecture 163 * support ioport mapping (HAS_IOPORT_MAP), the ioport mapping will 164 * be fixed to the range [ PCI_IOBASE, PCI_IOBASE+IO_SPACE_LIMIT [, 165 * and does not need unmapping with 'ioport_unmap()'. 166 * 167 * If you have different rules for your architecture, you need to 168 * implement your own pci_iounmap() that knows the rules for where 169 * and how IO vs MEM get mapped. 170 * 171 * This code is odd, and the ARCH_HAS/ARCH_WANTS #define logic comes 172 * from legacy <asm-generic/io.h> header file behavior. In particular, 173 * it would seem to make sense to do the iounmap(p) for the non-IO-space 174 * case here regardless, but that's not what the old header file code 175 * did. Probably incorrectly, but this is meant to be bug-for-bug 176 * compatible. 177 */ 178 #if defined(ARCH_WANTS_GENERIC_PCI_IOUNMAP) 179 180 void pci_iounmap(struct pci_dev *dev, void __iomem *p) 181 { 182 #ifdef ARCH_HAS_GENERIC_IOPORT_MAP 183 uintptr_t start = (uintptr_t) PCI_IOBASE; 184 uintptr_t addr = (uintptr_t) p; 185 186 if (addr >= start && addr < start + IO_SPACE_LIMIT) 187 return; 188 #endif 189 iounmap(p); 190 } 191 EXPORT_SYMBOL(pci_iounmap); 192 193 #endif /* ARCH_WANTS_GENERIC_PCI_IOUNMAP */ 194