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authorYuji Shimada <shimada-yxb@necst.nec.co.jp>2009-03-16 17:13:39 +0900
committerJesse Barnes <jbarnes@virtuousgeek.org>2009-03-20 10:48:15 -0700
commit32a9a682bef2f6fce7026bd94d1ce20028b0e52d (patch)
treea93225b3039585e8364ae3d411b22f63eebc8d70 /drivers/pci/quirks.c
parent1c8d7b0a562da06d3ebe83f01b1ed553205d1ae4 (diff)
PCI: allow assignment of memory resources with a specified alignment
This patch allows memory resources to be assigned with a specified alignment at boot-time or run-time. The patch is useful when we use PCI pass-through, because page-aligned memory resources are required to securely share PCI resources with guest drivers. If you want to assign the resource at boot time, please set "pci=resource_alignment=" boot parameter. This is format of "pci=resource_alignment=" boot parameter: [<order of align>@][<domain>:]<bus>:<slot>.<func>[; ...] Specifies alignment and device to reassign aligned memory resources. If <order of align> is not specified, PAGE_SIZE is used as alignment. PCI-PCI bridge can be specified, if resource windows need to be expanded. This is example: pci=resource_alignment=20@07:00.0;18@0f:00.0;00:1d.7 If you want to assign the resource at run-time, please set "/sys/bus/pci/resource_alignment" file, and hot-remove the device and hot-add the device. For this purpose, fakephp or PCI hotplug interfaces can be used. The format of "/sys/bus/pci/resource_alignment" file is the same with boot parameter. You can use "," instead of ";". For example: # cd /sys/bus/pci # echo -n 20@12:00.0 > resource_alignment # echo 1 > devices/0000:12:00.0/remove # echo 1 > rescan Reviewed-by: Alex Chiang <achiang@hp.com> Reviewed-by: Yu Zhao <yu.zhao@intel.com> Signed-off-by: Yuji Shimada <shimada-yxb@necst.nec.co.jp> Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Diffstat (limited to 'drivers/pci/quirks.c')
-rw-r--r--drivers/pci/quirks.c60
1 files changed, 60 insertions, 0 deletions
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 5aa2afb23ef..50233818a76 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -24,6 +24,7 @@
#include <linux/kallsyms.h>
#include <linux/dmi.h>
#include <linux/pci-aspm.h>
+#include <linux/ioport.h>
#include "pci.h"
int isa_dma_bridge_buggy;
@@ -34,6 +35,65 @@ int pcie_mch_quirk;
EXPORT_SYMBOL(pcie_mch_quirk);
#ifdef CONFIG_PCI_QUIRKS
+/*
+ * This quirk function disables the device and releases resources
+ * which is specified by kernel's boot parameter 'pci=resource_alignment='.
+ * It also rounds up size to specified alignment.
+ * Later on, the kernel will assign page-aligned memory resource back
+ * to that device.
+ */
+static void __devinit quirk_resource_alignment(struct pci_dev *dev)
+{
+ int i;
+ struct resource *r;
+ resource_size_t align, size;
+
+ if (!pci_is_reassigndev(dev))
+ return;
+
+ if (dev->hdr_type == PCI_HEADER_TYPE_NORMAL &&
+ (dev->class >> 8) == PCI_CLASS_BRIDGE_HOST) {
+ dev_warn(&dev->dev,
+ "Can't reassign resources to host bridge.\n");
+ return;
+ }
+
+ dev_info(&dev->dev, "Disabling device and release resources.\n");
+ pci_disable_device(dev);
+
+ align = pci_specified_resource_alignment(dev);
+ for (i=0; i < PCI_BRIDGE_RESOURCES; i++) {
+ r = &dev->resource[i];
+ if (!(r->flags & IORESOURCE_MEM))
+ continue;
+ size = resource_size(r);
+ if (size < align) {
+ size = align;
+ dev_info(&dev->dev,
+ "Rounding up size of resource #%d to %#llx.\n",
+ i, (unsigned long long)size);
+ }
+ r->end = size - 1;
+ r->start = 0;
+ }
+ /* Need to disable bridge's resource window,
+ * to enable the kernel to reassign new resource
+ * window later on.
+ */
+ if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE &&
+ (dev->class >> 8) == PCI_CLASS_BRIDGE_PCI) {
+ for (i = PCI_BRIDGE_RESOURCES; i < PCI_NUM_RESOURCES; i++) {
+ r = &dev->resource[i];
+ if (!(r->flags & IORESOURCE_MEM))
+ continue;
+ r->end = resource_size(r) - 1;
+ r->start = 0;
+ }
+ pci_disable_bridge_window(dev);
+ }
+}
+DECLARE_PCI_FIXUP_HEADER(PCI_ANY_ID, PCI_ANY_ID, quirk_resource_alignment);
+
/* The Mellanox Tavor device gives false positive parity errors
* Mark this device with a broken_parity_status, to allow
* PCI scanning code to "skip" this now blacklisted device.