PCI: skip ISA ioresource alignment on some systems
Skip ISA ioresource alignment on some systems
To conserve limited PCI i/o resource on some IBM multi-node systems, the
BIOS allocates (via _CRS) and expects the kernel to use addresses in
ranges currently excluded by pcibios_align_resource() [i386/pci/i386.c].
This change allows the kernel to use the currently excluded address
ranges on the IBM x3800, x3850, and x3950.
Signed-off-by: Gary Hade <gary.hade@us.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/arch/x86/pci/acpi.c b/arch/x86/pci/acpi.c
index bc8a44b..1dd6f3f 100644
--- a/arch/x86/pci/acpi.c
+++ b/arch/x86/pci/acpi.c
@@ -2,15 +2,57 @@
#include <linux/acpi.h>
#include <linux/init.h>
#include <linux/irq.h>
+#include <linux/dmi.h>
#include <asm/numa.h>
#include "pci.h"
+static int __devinit can_skip_ioresource_align(struct dmi_system_id *d)
+{
+ pci_probe |= PCI_CAN_SKIP_ISA_ALIGN;
+ printk(KERN_INFO "PCI: %s detected, can skip ISA alignment\n", d->ident);
+ return 0;
+}
+
+static struct dmi_system_id acpi_pciprobe_dmi_table[] = {
+/*
+ * Systems where PCI IO resource ISA alignment can be skipped
+ * when the ISA enable bit in the bridge control is not set
+ */
+ {
+ .callback = can_skip_ioresource_align,
+ .ident = "IBM System x3800",
+ .matches = {
+ DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
+ DMI_MATCH(DMI_PRODUCT_NAME, "x3800"),
+ },
+ },
+ {
+ .callback = can_skip_ioresource_align,
+ .ident = "IBM System x3850",
+ .matches = {
+ DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
+ DMI_MATCH(DMI_PRODUCT_NAME, "x3850"),
+ },
+ },
+ {
+ .callback = can_skip_ioresource_align,
+ .ident = "IBM System x3950",
+ .matches = {
+ DMI_MATCH(DMI_SYS_VENDOR, "IBM"),
+ DMI_MATCH(DMI_PRODUCT_NAME, "x3950"),
+ },
+ },
+ {}
+};
+
struct pci_bus * __devinit pci_acpi_scan_root(struct acpi_device *device, int domain, int busnum)
{
struct pci_bus *bus;
struct pci_sysdata *sd;
int pxm;
+ dmi_check_system(acpi_pciprobe_dmi_table);
+
/* Allocate per-root-bus (not per bus) arch-specific data.
* TODO: leak; this memory is never freed.
* It's arguable whether it's worth the trouble to care.
diff --git a/arch/x86/pci/i386.c b/arch/x86/pci/i386.c
index bcd2f94..055187b 100644
--- a/arch/x86/pci/i386.c
+++ b/arch/x86/pci/i386.c
@@ -33,6 +33,15 @@
#include "pci.h"
+static int
+skip_isa_ioresource_align(struct pci_dev *dev) {
+
+ if ((pci_probe & PCI_CAN_SKIP_ISA_ALIGN) &&
+ (dev->bus->bridge_ctl & PCI_BRIDGE_CTL_NO_ISA))
+ return 1;
+ return 0;
+}
+
/*
* We need to avoid collisions with `mirrored' VGA ports
* and other strange ISA hardware, so we always want the
@@ -50,9 +59,13 @@
pcibios_align_resource(void *data, struct resource *res,
resource_size_t size, resource_size_t align)
{
+ struct pci_dev *dev = data;
+
if (res->flags & IORESOURCE_IO) {
resource_size_t start = res->start;
+ if (skip_isa_ioresource_align(dev))
+ return;
if (start & 0x300) {
start = (start + 0x3ff) & ~0x3ff;
res->start = start;
diff --git a/arch/x86/pci/pci.h b/arch/x86/pci/pci.h
index 8c66f27..057f335 100644
--- a/arch/x86/pci/pci.h
+++ b/arch/x86/pci/pci.h
@@ -26,6 +26,7 @@
#define PCI_ASSIGN_ROMS 0x1000
#define PCI_BIOS_IRQ_SCAN 0x2000
#define PCI_ASSIGN_ALL_BUSSES 0x4000
+#define PCI_CAN_SKIP_ISA_ALIGN 0x8000
extern unsigned int pci_probe;
extern unsigned long pirq_table_addr;