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 #ifdef CONFIG_PCI 13 /** 14 * pci_iomap_range - create a virtual mapping cookie for a PCI BAR 15 * @dev: PCI device that owns the BAR 16 * @bar: BAR number 17 * @offset: map memory at the given offset in BAR 18 * @maxlen: max length of the memory to map 19 * 20 * Using this function you will get a __iomem address to your device BAR. 21 * You can access it using ioread*() and iowrite*(). These functions hide 22 * the details if this is a MMIO or PIO address space and will just do what 23 * you expect from them in the correct way. 24 * 25 * @maxlen specifies the maximum length to map. If you want to get access to 26 * the complete BAR from offset to the end, pass %0 here. 27 * */ 28 void __iomem *pci_iomap_range(struct pci_dev *dev, 29 int bar, 30 unsigned long offset, 31 unsigned long maxlen) 32 { 33 resource_size_t start = pci_resource_start(dev, bar); 34 resource_size_t len = pci_resource_len(dev, bar); 35 unsigned long flags = pci_resource_flags(dev, bar); 36 37 if (len <= offset || !start) 38 return NULL; 39 len -= offset; 40 start += offset; 41 if (maxlen && len > maxlen) 42 len = maxlen; 43 if (flags & IORESOURCE_IO) 44 return __pci_ioport_map(dev, start, len); 45 if (flags & IORESOURCE_MEM) 46 return ioremap(start, len); 47 /* What? */ 48 return NULL; 49 } 50 EXPORT_SYMBOL(pci_iomap_range); 51 52 /** 53 * pci_iomap_wc_range - create a virtual WC mapping cookie for a PCI BAR 54 * @dev: PCI device that owns the BAR 55 * @bar: BAR number 56 * @offset: map memory at the given offset in BAR 57 * @maxlen: max length of the memory to map 58 * 59 * Using this function you will get a __iomem address to your device BAR. 60 * You can access it using ioread*() and iowrite*(). These functions hide 61 * the details if this is a MMIO or PIO address space and will just do what 62 * you expect from them in the correct way. When possible write combining 63 * is used. 64 * 65 * @maxlen specifies the maximum length to map. If you want to get access to 66 * the complete BAR from offset to the end, pass %0 here. 67 * */ 68 void __iomem *pci_iomap_wc_range(struct pci_dev *dev, 69 int bar, 70 unsigned long offset, 71 unsigned long maxlen) 72 { 73 resource_size_t start = pci_resource_start(dev, bar); 74 resource_size_t len = pci_resource_len(dev, bar); 75 unsigned long flags = pci_resource_flags(dev, bar); 76 77 78 if (flags & IORESOURCE_IO) 79 return NULL; 80 81 if (len <= offset || !start) 82 return NULL; 83 84 len -= offset; 85 start += offset; 86 if (maxlen && len > maxlen) 87 len = maxlen; 88 89 if (flags & IORESOURCE_MEM) 90 return ioremap_wc(start, len); 91 92 /* What? */ 93 return NULL; 94 } 95 EXPORT_SYMBOL_GPL(pci_iomap_wc_range); 96 97 /** 98 * pci_iomap - create a virtual mapping cookie for a PCI BAR 99 * @dev: PCI device that owns the BAR 100 * @bar: BAR number 101 * @maxlen: length of the memory to map 102 * 103 * Using this function you will get a __iomem address to your device BAR. 104 * You can access it using ioread*() and iowrite*(). These functions hide 105 * the details if this is a MMIO or PIO address space and will just do what 106 * you expect from them in the correct way. 107 * 108 * @maxlen specifies the maximum length to map. If you want to get access to 109 * the complete BAR without checking for its length first, pass %0 here. 110 * */ 111 void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen) 112 { 113 return pci_iomap_range(dev, bar, 0, maxlen); 114 } 115 EXPORT_SYMBOL(pci_iomap); 116 117 /** 118 * pci_iomap_wc - create a virtual WC mapping cookie for a PCI BAR 119 * @dev: PCI device that owns the BAR 120 * @bar: BAR number 121 * @maxlen: length of the memory to map 122 * 123 * Using this function you will get a __iomem address to your device BAR. 124 * You can access it using ioread*() and iowrite*(). These functions hide 125 * the details if this is a MMIO or PIO address space and will just do what 126 * you expect from them in the correct way. When possible write combining 127 * is used. 128 * 129 * @maxlen specifies the maximum length to map. If you want to get access to 130 * the complete BAR without checking for its length first, pass %0 here. 131 * */ 132 void __iomem *pci_iomap_wc(struct pci_dev *dev, int bar, unsigned long maxlen) 133 { 134 return pci_iomap_wc_range(dev, bar, 0, maxlen); 135 } 136 EXPORT_SYMBOL_GPL(pci_iomap_wc); 137 138 /* 139 * pci_iounmap() somewhat illogically comes from lib/iomap.c for the 140 * CONFIG_GENERIC_IOMAP case, because that's the code that knows about 141 * the different IOMAP ranges. 142 * 143 * But if the architecture does not use the generic iomap code, and if 144 * it has _not_ defined it's own private pci_iounmap function, we define 145 * it here. 146 * 147 * NOTE! This default implementation assumes that if the architecture 148 * support ioport mapping (HAS_IOPORT_MAP), the ioport mapping will 149 * be fixed to the range [ PCI_IOBASE, PCI_IOBASE+IO_SPACE_LIMIT [, 150 * and does not need unmapping with 'ioport_unmap()'. 151 * 152 * If you have different rules for your architecture, you need to 153 * implement your own pci_iounmap() that knows the rules for where 154 * and how IO vs MEM get mapped. 155 * 156 * This code is odd, and the ARCH_HAS/ARCH_WANTS #define logic comes 157 * from legacy <asm-generic/io.h> header file behavior. In particular, 158 * it would seem to make sense to do the iounmap(p) for the non-IO-space 159 * case here regardless, but that's not what the old header file code 160 * did. Probably incorrectly, but this is meant to be bug-for-bug 161 * compatible. 162 */ 163 #if defined(ARCH_WANTS_GENERIC_PCI_IOUNMAP) 164 165 void pci_iounmap(struct pci_dev *dev, void __iomem *p) 166 { 167 #ifdef ARCH_HAS_GENERIC_IOPORT_MAP 168 uintptr_t start = (uintptr_t) PCI_IOBASE; 169 uintptr_t addr = (uintptr_t) p; 170 171 if (addr >= start && addr < start + IO_SPACE_LIMIT) 172 return; 173 #endif 174 iounmap(p); 175 } 176 EXPORT_SYMBOL(pci_iounmap); 177 178 #endif /* ARCH_WANTS_GENERIC_PCI_IOUNMAP */ 179 180 #endif /* CONFIG_PCI */ 181