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Commit 8cfc99b5 authored by Michael S. Tsirkin's avatar Michael S. Tsirkin Committed by Rusty Russell
Browse files

s390: add pci_iomap_range 



Virtio drivers should map the part of the range they need, not
necessarily all of it.
To this end, support mapping ranges within BAR on s390.
Since multiple ranges can now be mapped within a BAR, we keep track of
the number of mappings created, and only clear out the mapping for a BAR
when this number reaches 0.

Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: linux-pci@vger.kernel.org
Tested-by: default avatarSebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
Signed-off-by: default avatarRusty Russell <rusty@rustcorp.com.au>
parent eb29d8d2

arch/s390/include/asm/pci_io.h

+1 −0
Original line number Diff line number Diff line
@@ -16,6 +16,7 @@ 
struct zpci_iomap_entry {

	u32 fh;

	u8 bar;

	u16 count;

};



extern struct zpci_iomap_entry *zpci_iomap_start;

arch/s390/pci/pci.c

+27 −7
Original line number Diff line number Diff line
@@ -259,7 +259,10 @@ void __iowrite64_copy(void __iomem *to, const void *from, size_t count) 
}



/* Create a virtual mapping cookie for a PCI BAR */

void __iomem *pci_iomap(struct pci_dev *pdev, int bar, unsigned long max)

void __iomem *pci_iomap_range(struct pci_dev *pdev,

			      int bar,

			      unsigned long offset,

			      unsigned long max)

{

	struct zpci_dev *zdev =	get_zdev(pdev);

	u64 addr;
@@ -270,14 +273,27 @@ void __iomem *pci_iomap(struct pci_dev *pdev, int bar, unsigned long max) 


	idx = zdev->bars[bar].map_idx;

	spin_lock(&zpci_iomap_lock);

	if (zpci_iomap_start[idx].count++) {

		BUG_ON(zpci_iomap_start[idx].fh != zdev->fh ||

		       zpci_iomap_start[idx].bar != bar);

	} else {

		zpci_iomap_start[idx].fh = zdev->fh;

		zpci_iomap_start[idx].bar = bar;

	}

	/* Detect overrun */

	BUG_ON(!zpci_iomap_start[idx].count);

	spin_unlock(&zpci_iomap_lock);



	addr = ZPCI_IOMAP_ADDR_BASE | ((u64) idx << 48);

	return (void __iomem *) addr;

	return (void __iomem *) addr + offset;

}

EXPORT_SYMBOL_GPL(pci_iomap);

EXPORT_SYMBOL_GPL(pci_iomap_range);



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);



void pci_iounmap(struct pci_dev *pdev, void __iomem *addr)

{
@@ -285,8 +301,12 @@ void pci_iounmap(struct pci_dev *pdev, void __iomem *addr) 


	idx = (((__force u64) addr) & ~ZPCI_IOMAP_ADDR_BASE) >> 48;

	spin_lock(&zpci_iomap_lock);

	/* Detect underrun */

	BUG_ON(!zpci_iomap_start[idx].count);

	if (!--zpci_iomap_start[idx].count) {

		zpci_iomap_start[idx].fh = 0;

		zpci_iomap_start[idx].bar = 0;

	}

	spin_unlock(&zpci_iomap_lock);

}

EXPORT_SYMBOL_GPL(pci_iounmap);