[PATCH] PCI Quirk: 1K I/O space granularity on Intel P64H2

I've implemented a quirk to take advantage of the 1KB I/O space
granularity option on the Intel P64H2 PCI Bridge.  I had to change
probe.c because it sets the resource start and end to be aligned on 4k
boundaries (after the quirk sets them to 1k boundaries).  I've tested
this patch on a Unisys ES7000-600 both with and without the 1KB option
enabled.  I also tested this on a 2 processor Dell box that doesn't have
a P64H2 to make sure there were no negative affects there.

Signed-off-by: Dan Yeisley <dan.yeisley@unisys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
index 79be37a533973153729b0974691b79559f496a0c..00ba6a03dca56b44a94f555134995f3af2295158 100644 (file)
--- a/drivers/pci/probe.c
+++ b/drivers/pci/probe.c
@@ -264,8 +264,10 @@ void __devinit pci_read_bridge_bases(struct pci_bus *child)
 
        if (base <= limit) {
                res->flags = (io_base_lo & PCI_IO_RANGE_TYPE_MASK) | IORESOURCE_IO;
-               res->start = base;
-               res->end = limit + 0xfff;
+               if (!res->start)
+                       res->start = base;
+               if (!res->end)
+                       res->end = limit + 0xfff;
        }
 
        res = child->resource[1];

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index f28ebdd3958a557466ff347abc21b3c8f14d1a49..605f0df0bfba941f3090e8cd3025235a857fc972 100644 (file)
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -1342,6 +1342,32 @@ void pci_fixup_device(enum pci_fixup_pass pass, struct pci_dev *dev)
        pci_do_fixups(dev, start, end);
 }
 
+/* Enable 1k I/O space granularity on the Intel P64H2 */
+static void __devinit quirk_p64h2_1k_io(struct pci_dev *dev)
+{
+       u16 en1k;
+       u8 io_base_lo, io_limit_lo;
+       unsigned long base, limit;
+       struct resource *res = dev->resource + PCI_BRIDGE_RESOURCES;
+
+       pci_read_config_word(dev, 0x40, &en1k);
+
+       if (en1k & 0x200) {
+               printk(KERN_INFO "PCI: Enable I/O Space to 1 KB Granularity\n");
+
+               pci_read_config_byte(dev, PCI_IO_BASE, &io_base_lo);
+               pci_read_config_byte(dev, PCI_IO_LIMIT, &io_limit_lo);
+               base = (io_base_lo & (PCI_IO_RANGE_MASK | 0x0c)) << 8;
+               limit = (io_limit_lo & (PCI_IO_RANGE_MASK | 0x0c)) << 8;
+
+               if (base <= limit) {
+                       res->start = base;
+                       res->end = limit + 0x3ff;
+               }
+       }
+}
+DECLARE_PCI_FIXUP_HEADER(PCI_VENDOR_ID_INTEL,  0x1460,         quirk_p64h2_1k_io);
+
 EXPORT_SYMBOL(pcie_mch_quirk);
 #ifdef CONFIG_HOTPLUG
 EXPORT_SYMBOL(pci_fixup_device);