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>
diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
index 3290f11..753a567 100644
--- a/arch/s390/pci/pci.c
+++ b/arch/s390/pci/pci.c
@@ -259,7 +259,10 @@
}
/* 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 @@
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 @@
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);