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authorMichael S. Tsirkin <mst@redhat.com>2011-11-24 20:45:20 +0200
committerMichael S. Tsirkin <mst@redhat.com>2011-11-28 21:12:42 +0200
commit66eab4df288aaee75938ae99877c4f759fc6d56c (patch)
tree0b663bfe2d464a55c2a85b27140a53b32f261542 /lib/pci_iomap.c
parent4673ca8eb3690832e76371371955a8b02e1f59d4 (diff)
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lib: add GENERIC_PCI_IOMAP
Many architectures want a generic pci_iomap but not the rest of iomap.c. Split that to a separate .c file and add a new config symbol. select automatically by GENERIC_IOMAP. Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Diffstat (limited to 'lib/pci_iomap.c')
-rw-r--r--lib/pci_iomap.c48
1 files changed, 48 insertions, 0 deletions
diff --git a/lib/pci_iomap.c b/lib/pci_iomap.c
new file mode 100644
index 000000000000..4b0fdc22e688
--- /dev/null
+++ b/lib/pci_iomap.c
@@ -0,0 +1,48 @@
+/*
+ * Implement the default iomap interfaces
+ *
+ * (C) Copyright 2004 Linus Torvalds
+ */
+#include <linux/pci.h>
+#include <linux/io.h>
+
+#include <linux/export.h>
+
+#ifdef CONFIG_PCI
+/**
+ * pci_iomap - create a virtual mapping cookie for a PCI BAR
+ * @dev: PCI device that owns the BAR
+ * @bar: BAR number
+ * @maxlen: length of the memory to map
+ *
+ * Using this function you will get a __iomem address to your device BAR.
+ * You can access it using ioread*() and iowrite*(). These functions hide
+ * the details if this is a MMIO or PIO address space and will just do what
+ * you expect from them in the correct way.
+ *
+ * @maxlen specifies the maximum length to map. If you want to get access to
+ * the complete BAR without checking for its length first, pass %0 here.
+ * */
+void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen)
+{
+ resource_size_t start = pci_resource_start(dev, bar);
+ resource_size_t len = pci_resource_len(dev, bar);
+ unsigned long flags = pci_resource_flags(dev, bar);
+
+ if (!len || !start)
+ return NULL;
+ if (maxlen && len > maxlen)
+ len = maxlen;
+ if (flags & IORESOURCE_IO)
+ return ioport_map(start, len);
+ if (flags & IORESOURCE_MEM) {
+ if (flags & IORESOURCE_CACHEABLE)
+ return ioremap(start, len);
+ return ioremap_nocache(start, len);
+ }
+ /* What? */
+ return NULL;
+}
+
+EXPORT_SYMBOL(pci_iomap);
+#endif /* CONFIG_PCI */