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Commit eb29d8d2 authored by Michael S. Tsirkin's avatar Michael S. Tsirkin Committed by Rusty Russell
Browse files

pci: add pci_iomap_range



Virtio drivers should map the part of the BAR they need, not necessarily
all of it.

Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-pci@vger.kernel.org
Acked-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
parent 54cfe08b
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+10 −0
Original line number Diff line number Diff line
@@ -15,6 +15,9 @@ struct pci_dev;
#ifdef CONFIG_PCI
/* Create a virtual mapping cookie for a PCI BAR (memory or IO) */
extern void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long max);
extern void __iomem *pci_iomap_range(struct pci_dev *dev, int bar,
				     unsigned long offset,
				     unsigned long maxlen);
/* Create a virtual mapping cookie for a port on a given PCI device.
 * Do not call this directly, it exists to make it easier for architectures
 * to override */
@@ -30,6 +33,13 @@ static inline void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned lon
{
	return NULL;
}

static inline void __iomem *pci_iomap_range(struct pci_dev *dev, int bar,
					    unsigned long offset,
					    unsigned long maxlen)
{
	return NULL;
}
#endif

#endif /* __ASM_GENERIC_IO_H */
+30 −5
Original line number Diff line number Diff line
@@ -10,10 +10,11 @@

#ifdef CONFIG_PCI
/**
 * pci_iomap - create a virtual mapping cookie for a PCI BAR
 * pci_iomap_range - 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
 * @offset: map memory at the given offset in BAR
 * @maxlen: max 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
@@ -21,16 +22,21 @@
 * 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.
 * the complete BAR from offset to the end, pass %0 here.
 * */
void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen)
void __iomem *pci_iomap_range(struct pci_dev *dev,
			      int bar,
			      unsigned long offset,
			      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)
	if (len <= offset || !start)
		return NULL;
	len -= offset;
	start += offset;
	if (maxlen && len > maxlen)
		len = maxlen;
	if (flags & IORESOURCE_IO)
@@ -43,6 +49,25 @@ void __iomem *pci_iomap(struct pci_dev *dev, int bar, unsigned long maxlen)
	/* What? */
	return NULL;
}
EXPORT_SYMBOL(pci_iomap_range);

/**
 * 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)
{
	return pci_iomap_range(dev, bar, 0, maxlen);
}
EXPORT_SYMBOL(pci_iomap);
#endif /* CONFIG_PCI */