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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

include/asm-generic/pci_iomap.h

+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 */

lib/pci_iomap.c

+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 */