This patch assigns memory resource with specified alignment at
boot-time or run-time. The patch is useful when we use PCI
pass-through, because page-aligned memory resource is required for pci
pass-through. The patch can be used for general purposes.
The patch is based on the discussion in linux-pci. You can read it at
following URL.
http://markmail.org/thread/wnxphqtqxhr37ija
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;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 can be used.
The format of the file is the same with boot parameter. You can use
"," instead of ";".
This is example:
# /sbin/modprobe fakephp
# cd /sys/bus/pci
# echo -n 20@0d:00.0 > resource_alignment
# cat slots/fake13/address
0000:0d:00
# echo -n 0 > slots/fake13/power
# echo -n 1 > slots/fake1/power
Thanks,
--
Yuji Shimada
Signed-off-by: Yuji Shimada <shimada-yxb@xxxxxxxxxxxxxxx>
diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index d8362cf..1f40888 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -1754,6 +1754,15 @@ and is between 256 and 4096 characters. It is defined in the file
cbmemsize=nn[KMG] The fixed amount of bus space which is
reserved for the CardBus bridge's memory
window. The default value is 64 megabytes.
+ resource_alignment=
+ Format:
+ [<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.
pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power
Management.
diff --git a/drivers/pci/Kconfig b/drivers/pci/Kconfig
index 2a4501d..cc2c777 100644
--- a/drivers/pci/Kconfig
+++ b/drivers/pci/Kconfig
@@ -59,3 +59,8 @@ config HT_IRQ
This allows native hypertransport devices to use interrupts.
If unsure say Y.
+
+config RESOURCE_ALIGNMENT_PARAM
+ bool
+ depends on PCI_QUIRKS
+ default y
diff --git a/drivers/pci/pci.c b/drivers/pci/pci.c
index 4880755..bca4f26 100644
--- a/drivers/pci/pci.c
+++ b/drivers/pci/pci.c
@@ -22,6 +22,11 @@
#include <asm/dma.h> /* isa_dma_bridge_buggy */
#include "pci.h"
+#ifdef CONFIG_RESOURCE_ALIGNMENT_PARAM
+#include <linux/device.h>
+#include <asm/setup.h>
+#endif /* CONFIG_RESOURCE_ALIGNMENT_PARAM */
+
unsigned int pci_pm_d3_delay = PCI_PM_D3_WAIT;
#ifdef CONFIG_PCI_DOMAINS
@@ -2353,6 +2358,133 @@ int pci_resource_bar(struct pci_dev *dev, int resno, enum pci_bar_type *type)
return 0;
}
+#ifdef CONFIG_RESOURCE_ALIGNMENT_PARAM
+#define RESOURCE_ALIGNMENT_PARAM_SIZE COMMAND_LINE_SIZE
+static char resource_alignment_param[RESOURCE_ALIGNMENT_PARAM_SIZE] = {0};
+spinlock_t resource_alignment_lock = SPIN_LOCK_UNLOCKED;
+
+/**
+ * pci_specified_resource_alignemnt - get resource alignment specified by user.
+ * @dev: the PCI device to get
+ *
+ * RETURNS: Resrouce alignment if it is specified.
+ * Zero if it is not specified.
+ */
+resource_size_t pci_specified_resource_alignment(struct pci_dev *dev)
+{
+ int seg, bus, slot, func, align_order, count;
+ resource_size_t align = 0;
+ char *p;
+ unsigned long flags;
+
+ spin_lock_irqsave(&resource_alignment_lock, flags);
+ p = resource_alignment_param;
+ while (*p) {
+ count = 0;
+ if (sscanf(p, "%d%n", &align_order, &count) == 1 &&
+ p[count] == '@') {
+ p += count + 1;
+ } else {
+ align_order = -1;
+ }
+ if (sscanf(p, "%x:%x:%x.%x%n",
+ &seg, &bus, &slot, &func, &count) != 4) {
+ seg = 0;
+ if (sscanf(p, "%x:%x.%x%n",
+ &bus, &slot, &func, &count) != 3) {
+ /* Invalid format */
+ printk(KERN_ERR "PCI: Can't parse "
+ "resource_alignment parameter: %s\n",
+ p);
+ break;
+ }
+ }
+ p += count;
+ if (seg == pci_domain_nr(dev->bus) &&
+ bus == dev->bus->number &&
+ slot == PCI_SLOT(dev->devfn) &&
+ func == PCI_FUNC(dev->devfn)) {
+ if (align_order == -1) {
+ align = PAGE_SIZE;
+ } else {
+ align = 1 << align_order;
+ }
+ /* Found */
+ break;
+ }
+ if (*p != ';' && *p != ',') {
+ /* End of param or invalid format */
+ break;
+ }
+ p++;
+ }
+ spin_unlock_irqrestore(&resource_alignment_lock, flags);
+ return align;
+}
+
+/**
+ * pci_is_reassigndev - check if specified PCI is target device to reassign
+ * @dev: the PCI device to check
+ *
+ * RETURNS: non-zero for PCI device is a target device to reassign,
+ * or zero is not.
+ */
+int pci_is_reassigndev(struct pci_dev *dev)
+{
+ return (pci_specified_resource_alignment(dev) != 0);
+}
+
+ssize_t pci_set_resource_alignment_param(const char *buf, size_t count)
+{
+ unsigned long flags;
+ if (RESOURCE_ALIGNMENT_PARAM_SIZE - 1 < count)
+ count = RESOURCE_ALIGNMENT_PARAM_SIZE - 1;
+ spin_lock_irqsave(&resource_alignment_lock, flags);
+ strncpy(resource_alignment_param, buf, count);
+ resource_alignment_param[count] = '\0';
+ spin_unlock_irqrestore(&resource_alignment_lock, flags);
+ return count;
+}
+
+ssize_t pci_get_resource_alignment_param(char *buf, size_t size)
+{
+ unsigned long flags;
+ size_t count;
+ spin_lock_irqsave(&resource_alignment_lock, flags);
+ count = snprintf("%s", size, resource_alignment_param);
+ spin_unlock_irqrestore(&resource_alignment_lock, flags);
+ return count;
+}
+
+static void __devinit pci_resource_alignment_setup(char *str)
+{
+ pci_set_resource_alignment_param(str, strlen(str));
+}
+
+static ssize_t pci_resource_alignment_show(struct bus_type *bus, char *buf)
+{
+ return pci_get_resource_alignment_param(buf, PAGE_SIZE);
+}
+
+static ssize_t pci_resource_alignment_store(struct bus_type *bus,
+ const char *buf, size_t count)
+{
+ return pci_set_resource_alignment_param(buf, count);
+}
+
+BUS_ATTR(resource_alignment, 0644, pci_resource_alignment_show,
+ pci_resource_alignment_store);
+
+static int __init pci_resource_alignment_sysfs_init(void)
+{
+ return bus_create_file(&pci_bus_type,
+ &bus_attr_resource_alignment);
+}
+
+late_initcall(pci_resource_alignment_sysfs_init);
+
+#endif /* CONFIG_RESOURCE_ALIGNMENT_PARAM */
+
static void __devinit pci_no_domains(void)
{
#ifdef CONFIG_PCI_DOMAINS
@@ -2401,6 +2533,8 @@ static int __init pci_setup(char *str)
pci_cardbus_io_size = memparse(str + 9, &str);
} else if (!strncmp(str, "cbmemsize=", 10)) {
pci_cardbus_mem_size = memparse(str + 10, &str);
+ } else if (!strncmp(str, "resource_alignment=", 19)) {
+ pci_resource_alignment_setup(str + 19);
} else {
printk(KERN_ERR "PCI: Unknown option `%s'\n",
str);
diff --git a/drivers/pci/pci.h b/drivers/pci/pci.h
index 26ddf78..ee41af9 100644
--- a/drivers/pci/pci.h
+++ b/drivers/pci/pci.h
@@ -195,4 +195,10 @@ static inline int pci_ari_enabled(struct pci_bus *bus)
return bus->self && bus->self->ari_enabled;
}
+#ifdef CONFIG_PCI_QUIRKS
+extern int pci_is_reassigndev(struct pci_dev *dev);
+resource_size_t pci_specified_resource_alignment(struct pci_dev *dev);
+extern void pci_disable_bridge_window(struct pci_dev *dev);
+#endif
+
#endif /* DRIVERS_PCI_H */
diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index baad093..e2eecc1 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -33,6 +33,63 @@ 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 round up size to specified alignment.
+ * Later on, 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) {
+ /* PCI Host Bridge isn't a target device */
+ dev_warn(&dev->dev,
+ "Can't reassign resources to Host Bridge.\n");
+ return;
+ }
+
+ dev_info(&dev->dev, "Disable device and release resources.\n");
+ pci_disable_device(dev);
+
+ align = pci_specified_resource_alignment(dev);
+ for (i=0; i < PCI_NUM_RESOURCES; i++) {
+ r = &dev->resource[i];
+ if (!(r->flags & IORESOURCE_MEM))
+ continue;
+ size = r->end - r->start + 1;
+ if (size < align) {
+ size = align;
+ dev_info(&dev->dev,
+ "Round up size of resource #%d to %#llx.\n",
+ i, (unsigned long long)size);
+ }
+ r->end = size - 1;
+ r->start = 0;
+
+ if (i < PCI_BRIDGE_RESOURCES) {
+ pci_update_resource(dev, i);
+ }
+ }
+ /* need to disable bridge's resource window,
+ * to make kernel enable to reassign new resource
+ * window later on.
+ */
+ if (dev->hdr_type == PCI_HEADER_TYPE_BRIDGE &&
+ (dev->class >> 8) == PCI_CLASS_BRIDGE_PCI) {
+ 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.
diff --git a/drivers/pci/setup-res.c b/drivers/pci/setup-res.c
index 32e8d88..a73285d 100644
--- a/drivers/pci/setup-res.c
+++ b/drivers/pci/setup-res.c
@@ -120,6 +120,21 @@ int pci_claim_resource(struct pci_dev *dev, int resource)
return err;
}
+#ifdef CONFIG_PCI_QUIRKS
+void pci_disable_bridge_window(struct pci_dev *dev)
+{
+ dev_dbg(&dev->dev, "Disable bridge window.\n");
+
+ /* MMIO Base/Limit */
+ pci_write_config_dword(dev, PCI_MEMORY_BASE, 0x0000fff0);
+
+ /* Prefetchable MMIO Base/Limit */
+ pci_write_config_dword(dev, PCI_PREF_LIMIT_UPPER32, 0);
+ pci_write_config_dword(dev, PCI_PREF_MEMORY_BASE, 0x0000fff0);
+ pci_write_config_dword(dev, PCI_PREF_BASE_UPPER32, 0xffffffff);
+}
+#endif /* CONFIG_PCI_QUIRKS */
+
int pci_assign_resource(struct pci_dev *dev, int resno)
{
struct pci_bus *bus = dev->bus;
--
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