From: Bhavana Nagendra <bnagendr@redhat.com>
Subject: [RHEL5.0] : /proc/mtrr interface MTRR bug fix
Date: Tue, 23 Jan 2007 09:04:59 -0500
Bugzilla: 223821
Message-Id: <45B6160B.6090503@redhat.com>
Changelog: x86: /proc/mtrr interface MTRR bug fix


This patch fixes two bugs in /proc/mtrr interface and addressess BZ 223821:
1) If physical address size crosses the 44 bit boundary size_or_mask is 
evaluated
incorrectly.
2) size_and_mask limits physical base address for an MTRR to be less 
than 44 bit.


--- linux-2.6.18.x86_64/arch/i386/kernel/cpu/mtrr/main.c.orig	2007-01-23 08:54:46.000000000 -0500
+++ linux-2.6.18.x86_64/arch/i386/kernel/cpu/mtrr/main.c	2007-01-23 08:57:18.000000000 -0500
@@ -50,7 +50,7 @@ u32 num_var_ranges = 0;
 unsigned int *usage_table;
 static DEFINE_MUTEX(mtrr_mutex);
 
-u32 size_or_mask, size_and_mask;
+u64 size_or_mask, size_and_mask;
 
 static struct mtrr_ops * mtrr_ops[X86_VENDOR_NUM] = {};
 
@@ -633,8 +633,8 @@ void __init mtrr_bp_init(void)
 			     boot_cpu_data.x86_mask == 0x4))
 				phys_addr = 36;
 
-			size_or_mask = ~((1 << (phys_addr - PAGE_SHIFT)) - 1);
-			size_and_mask = ~size_or_mask & 0xfff00000;
+			size_or_mask = ~((1ULL << (phys_addr - PAGE_SHIFT)) - 1);
+			size_and_mask = ~size_or_mask & 0xfffff00000ULL;
 		} else if (boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR &&
 			   boot_cpu_data.x86 == 6) {
 			/* VIA C* family have Intel style MTRRs, but
--- linux-2.6.18.x86_64/arch/i386/kernel/cpu/mtrr/mtrr.h.orig	2007-01-23 08:54:58.000000000 -0500
+++ linux-2.6.18.x86_64/arch/i386/kernel/cpu/mtrr/mtrr.h	2007-01-23 08:57:43.000000000 -0500
@@ -83,7 +83,7 @@ void get_mtrr_state(void);
 
 extern void set_mtrr_ops(struct mtrr_ops * ops);
 
-extern u32 size_or_mask, size_and_mask;
+extern u64 size_or_mask, size_and_mask;
 extern struct mtrr_ops * mtrr_if;
 
 #define is_cpu(vnd)	(mtrr_if && mtrr_if->vendor == X86_VENDOR_##vnd)