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: Sebastian Ott <sebott@linux.vnet.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This commit is contained in:
Michael S. Tsirkin 2013-05-29 11:52:21 +09:30 committed by Rusty Russell
parent eb29d8d2aa
commit 8cfc99b583
2 changed files with 28 additions and 7 deletions
arch/s390
include/asm
pci

View File

@ -16,6 +16,7 @@
struct zpci_iomap_entry {
u32 fh;
u8 bar;
u16 count;
};
extern struct zpci_iomap_entry *zpci_iomap_start;

View File

@ -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);
zpci_iomap_start[idx].fh = zdev->fh;
zpci_iomap_start[idx].bar = bar;
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);
zpci_iomap_start[idx].fh = 0;
zpci_iomap_start[idx].bar = 0;
/* 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);