1 /* 2 * Implement the default iomap interfaces 3 * 4 * (C) Copyright 2004 Linus Torvalds 5 */ 6 #include <linux/pci.h> 7 #include <linux/io.h> 8 9 #include <linux/export.h> 10 11 #ifdef CONFIG_PCI 12 /** 13 * pci_iomap - create a virtual mapping cookie for a PCI BAR 14 * @dev: PCI device that owns the BAR 15 * @bar: BAR number 16 * @maxlen: length of the memory to map 17 * 18 * Using this function you will get a __iomem address to your device BAR. 19 * You can access it using ioread*() and iowrite*(). These functions hide 20 * the details if this is a MMIO or PIO address space and will just do what 21 * you expect from them in the correct way. 22 * 23 * @maxlen specifies the maximum length to map. If you want to get access to 24 * the complete BAR without checking for its length first, pass %0 here. 25 * */ 26 void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen) 27 { 28 resource_size_t start = pci_resource_start(dev, bar); 29 resource_size_t len = pci_resource_len(dev, bar); 30 unsigned long flags = pci_resource_flags(dev, bar); 31 32 if (!len || !start) 33 return NULL; 34 if (maxlen && len > maxlen) 35 len = maxlen; 36 if (flags & IORESOURCE_IO) 37 return __pci_ioport_map(dev, start, len); 38 if (flags & IORESOURCE_MEM) { 39 if (flags & IORESOURCE_CACHEABLE) 40 return ioremap(start, len); 41 return ioremap_nocache(start, len); 42 } 43 /* What? */ 44 return NULL; 45 } 46 47 EXPORT_SYMBOL(pci_iomap); 48 #endif /* CONFIG_PCI */ 49