Re: SNB PCI root information

[Yinghai Lu <yinghai@kernel.org>]

[-- Attachment #1: Type: text/plain, Size: 496 bytes --]

On Wed, Jun 20, 2012 at 10:59 AM, Ulrich Drepper <drepper@gmail.com> wrote:
> On Wed, Jun 20, 2012 at 1:17 PM, Bjorn Helgaas <bhelgaas@google.com> wrote:
>
> I'd be willing to go with Yinghai's recommendation and give the BIOS
> writers the benefit of a doubt that they get things right.  If they
> prove to be incapable again we can still change the option handling to
> overwrite the kernel setting regardless.

good, please check updated patch with fix from you.

Thanks

Yinghai

[-- Attachment #2: busnum_node_v2.patch --]
[-- Type: application/octet-stream, Size: 2359 bytes --]

Subject: [PATCH] PCI, X86: busnum/node boot command line for missing _PXM

Some intel new sandybridge or newer two sockets system do support support numa
for pci devices. But BIOS does not provide _PXM under those root bus in DSDT.

Add boot command line, so user could have chance to input node info before
BIOS guys figure out to add _PXM.

Fold fix from Ulrich to use ";" instead of ",".
| The problem is the pci= parameter
| handling uses ',' to separate parameters and therefore the second PCI
| root information, separated by a comma, is interpreted as a new pci=
| parameter.

Reported-by: Ulrich Drepper <drepper@gmail.com>
Tested-by: Ulrich Drepper <drepper@gmail.com>
Signed-off-by: Yinghai Lu <yinghai@kernel.org>

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index a92c5eb..a66485f 100644
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -2190,6 +2190,10 @@ bytes respectively. Such letter suffixes can also be entirely omitted.
 				off: Turn realloc off
 				on: Turn realloc on
 		realloc		same as realloc=on
+		busnum_node=
+				Format:
+				<bus>:<node>[; ...]
+				Specifies node for bus, only works for missing _PXM
 		noari		do not use PCIe ARI.
 		pcie_scan_all	Scan all possible PCIe devices.  Otherwise we
 				only look for one device below a PCIe downstream
diff --git a/arch/x86/pci/common.c b/arch/x86/pci/common.c
index 0ad990a..a6527fe 100644
--- a/arch/x86/pci/common.c
+++ b/arch/x86/pci/common.c
@@ -494,6 +494,28 @@ int __init pcibios_init(void)
 	return 0;
 }
 
+static void __init parse_busnum_node(char *str)
+{
+	int bus, node, count;
+	char *p;
+
+	p = str;
+	while (*p) {
+		count = 0;
+		if (sscanf(p, "%x:%x%n", &bus, &node, &count) != 2) {
+			printk(KERN_ERR "PCI: Can't parse busnum_node input: %s\n",
+					p);
+			break;
+		}
+		set_mp_bus_to_node(bus, node);
+		p += count;
+		if (*p != ';')
+			break;
+		p++;
+	}
+}
+
+
 char * __devinit  pcibios_setup(char *str)
 {
 	if (!strcmp(str, "off")) {
@@ -579,6 +601,9 @@ char * __devinit  pcibios_setup(char *str)
 	} else if (!strcmp(str, "nocrs")) {
 		pci_probe |= PCI_ROOT_NO_CRS;
 		return NULL;
+	} else if (!strncmp(str, "busnum_node=", 12)) {
+		parse_busnum_node(str + 12);
+		return NULL;
 	} else if (!strcmp(str, "earlydump")) {
 		pci_early_dump_regs = 1;
 		return NULL;