Re: [PATCH 2/3]: x86-64: Handle SRAT v1 and v2 consistently

[Kurt Garloff]

Hi,

x86-64 was rather inconsistent prior to this patch; it used 8 bits 
for the pxm field in cpu_affinity, but 32 bits in mem_affinity.
This patch makes it consistent: Either use 8 bits consistently (SRAT
rev 1 or lower) or 32 bits (SRAT rev 2 or higher).

This is patch 2/3.
-- 
Kurt Garloff, VP OPS Partner Engineering -- Novell Inc.
From: Kurt Garloff <garloff@xxxxxxx>
Subject: Use SRAT table rev to use 8bit or 32bit PXM fields (x86-64)
References: bnc#503038

In SRAT v1, we had 8bit proximity domain (PXM) fields; SRAT v2 provides
32bits for these. The new fields were reserved before.
According to the ACPI spec, the OS must disregrard reserved fields.

x86-64 was rather inconsistent prior to this patch; it used 8 bits 
for the pxm field in cpu_affinity, but 32 bits in mem_affinity.
This patch makes it consistent: Either use 8 bits consistently (SRAT
rev 1 or lower) or 32 bits (SRAT rev 2 or higher).

This is patch 2/3.

Signed-off-by: Kurt Garloff <garloff@xxxxxxx>

diff -r a4ed8abcc815 arch/x86/mm/srat_64.c
--- a/arch/x86/mm/srat_64.c	Sat May 16 13:41:28 2009 -0700
+++ b/arch/x86/mm/srat_64.c	Mon May 18 10:45:40 2009 +0200
@@ -164,6 +164,8 @@
 	if ((pa->flags & ACPI_SRAT_CPU_ENABLED) == 0)
 		return;
 	pxm = pa->proximity_domain_lo;
+	if (acpi_srat_revision >= 2)
+		pxm |= *((unsigned int*)pa->proximity_domain_hi) << 8;
 	node = setup_node(pxm);
 	if (node < 0) {
 		printk(KERN_ERR "SRAT: Too many proximity domains %x\n", pxm);
@@ -275,6 +277,8 @@
 	start = ma->base_address;
 	end = start + ma->length;
 	pxm = ma->proximity_domain;
+	if (acpi_srat_revision <= 1)
+		pxm &= 0xff;
 	node = setup_node(pxm);
 	if (node < 0) {
 		printk(KERN_ERR "SRAT: Too many proximity domains.\n");

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