[tip:x86/mm] x86: Fix /proc/mtrr with base/size more than 44bits
From: tip-bot for Yinghai Lu
Date: Tue Jun 25 2013 - 18:52:03 EST
Commit-ID: d5c78673b1b28467354c2c30c3d4f003666ff385
Gitweb: http://git.kernel.org/tip/d5c78673b1b28467354c2c30c3d4f003666ff385
Author: Yinghai Lu <yinghai@xxxxxxxxxx>
AuthorDate: Thu, 13 Jun 2013 15:33:35 -0700
Committer: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
CommitDate: Tue, 25 Jun 2013 13:08:10 -0700
x86: Fix /proc/mtrr with base/size more than 44bits
On one sytem that mtrr range is more then 44bits, in dmesg we have
[ 0.000000] MTRR default type: write-back
[ 0.000000] MTRR fixed ranges enabled:
[ 0.000000] 00000-9FFFF write-back
[ 0.000000] A0000-BFFFF uncachable
[ 0.000000] C0000-DFFFF write-through
[ 0.000000] E0000-FFFFF write-protect
[ 0.000000] MTRR variable ranges enabled:
[ 0.000000] 0 [000080000000-0000FFFFFFFF] mask 3FFF80000000 uncachable
[ 0.000000] 1 [380000000000-38FFFFFFFFFF] mask 3F0000000000 uncachable
[ 0.000000] 2 [000099000000-000099FFFFFF] mask 3FFFFF000000 write-through
[ 0.000000] 3 [00009A000000-00009AFFFFFF] mask 3FFFFF000000 write-through
[ 0.000000] 4 [381FFA000000-381FFBFFFFFF] mask 3FFFFE000000 write-through
[ 0.000000] 5 [381FFC000000-381FFC0FFFFF] mask 3FFFFFF00000 write-through
[ 0.000000] 6 [0000AD000000-0000ADFFFFFF] mask 3FFFFF000000 write-through
[ 0.000000] 7 [0000BD000000-0000BDFFFFFF] mask 3FFFFF000000 write-through
[ 0.000000] 8 disabled
[ 0.000000] 9 disabled
but /proc/mtrr report wrong:
reg00: base=0x080000000 ( 2048MB), size= 2048MB, count=1: uncachable
reg01: base=0x80000000000 (8388608MB), size=1048576MB, count=1: uncachable
reg02: base=0x099000000 ( 2448MB), size= 16MB, count=1: write-through
reg03: base=0x09a000000 ( 2464MB), size= 16MB, count=1: write-through
reg04: base=0x81ffa000000 (8519584MB), size= 32MB, count=1: write-through
reg05: base=0x81ffc000000 (8519616MB), size= 1MB, count=1: write-through
reg06: base=0x0ad000000 ( 2768MB), size= 16MB, count=1: write-through
reg07: base=0x0bd000000 ( 3024MB), size= 16MB, count=1: write-through
reg08: base=0x09b000000 ( 2480MB), size= 16MB, count=1: write-combining
so bit 44 and bit 45 get cut off.
We have problems in arch/x86/kernel/cpu/mtrr/generic.c::generic_get_mtrr().
1. for base, we miss cast base_lo to 64bit before shifting.
Fix that by adding u64 casting.
2. for size, it only can handle 44 bits aka 32bits + page_shift
Fix that with 64bit mask instead of 32bit mask_lo, then range could be
more than 44bits.
At the same time, we need to update size_or_mask for old cpus that does
support cpuid 0x80000008 to get phys_addr. Need to set high 32bits
to all 1s, otherwise will not get correct size for them.
Also fix mtrr_add_page: it should check base and (base + size - 1)
instead of base and size, as base and size could be small but
base + size could bigger enough to be out of boundary. We can
use boot_cpu_data.x86_phys_bits directly to avoid size_or_mask.
So When are we going to have size more than 44bits? that is 16TiB.
after patch we have right ouput:
reg00: base=0x080000000 ( 2048MB), size= 2048MB, count=1: uncachable
reg01: base=0x380000000000 (58720256MB), size=1048576MB, count=1: uncachable
reg02: base=0x099000000 ( 2448MB), size= 16MB, count=1: write-through
reg03: base=0x09a000000 ( 2464MB), size= 16MB, count=1: write-through
reg04: base=0x381ffa000000 (58851232MB), size= 32MB, count=1: write-through
reg05: base=0x381ffc000000 (58851264MB), size= 1MB, count=1: write-through
reg06: base=0x0ad000000 ( 2768MB), size= 16MB, count=1: write-through
reg07: base=0x0bd000000 ( 3024MB), size= 16MB, count=1: write-through
reg08: base=0x09b000000 ( 2480MB), size= 16MB, count=1: write-combining
-v2: simply checking in mtrr_add_page according to hpa.
[ hpa: This probably wants to go into -stable only after having sat in
mainline for a bit. It is not a regression. ]
Signed-off-by: Yinghai Lu <yinghai@xxxxxxxxxx>
Link: http://lkml.kernel.org/r/1371162815-29931-1-git-send-email-yinghai@xxxxxxxxxx
Cc: <stable@xxxxxxxxxxxxxxx>
Signed-off-by: H. Peter Anvin <hpa@xxxxxxxxxxxxxxx>
---
arch/x86/kernel/cpu/mtrr/generic.c | 21 +++++++++++----------
arch/x86/kernel/cpu/mtrr/main.c | 16 +++++++++-------
2 files changed, 20 insertions(+), 17 deletions(-)
diff --git a/arch/x86/kernel/cpu/mtrr/generic.c b/arch/x86/kernel/cpu/mtrr/generic.c
index fa72a39..3982357 100644
--- a/arch/x86/kernel/cpu/mtrr/generic.c
+++ b/arch/x86/kernel/cpu/mtrr/generic.c
@@ -510,8 +510,9 @@ generic_get_free_region(unsigned long base, unsigned long size, int replace_reg)
static void generic_get_mtrr(unsigned int reg, unsigned long *base,
unsigned long *size, mtrr_type *type)
{
- unsigned int mask_lo, mask_hi, base_lo, base_hi;
- unsigned int tmp, hi;
+ u32 mask_lo, mask_hi, base_lo, base_hi;
+ unsigned int hi;
+ u64 tmp, mask;
/*
* get_mtrr doesn't need to update mtrr_state, also it could be called
@@ -532,18 +533,18 @@ static void generic_get_mtrr(unsigned int reg, unsigned long *base,
rdmsr(MTRRphysBase_MSR(reg), base_lo, base_hi);
/* Work out the shifted address mask: */
- tmp = mask_hi << (32 - PAGE_SHIFT) | mask_lo >> PAGE_SHIFT;
- mask_lo = size_or_mask | tmp;
+ tmp = (u64)mask_hi << (32 - PAGE_SHIFT) | mask_lo >> PAGE_SHIFT;
+ mask = size_or_mask | tmp;
/* Expand tmp with high bits to all 1s: */
- hi = fls(tmp);
+ hi = fls64(tmp);
if (hi > 0) {
- tmp |= ~((1<<(hi - 1)) - 1);
+ tmp |= ~((1ULL<<(hi - 1)) - 1);
- if (tmp != mask_lo) {
+ if (tmp != mask) {
printk(KERN_WARNING "mtrr: your BIOS has configured an incorrect mask, fixing it.\n");
add_taint(TAINT_FIRMWARE_WORKAROUND, LOCKDEP_STILL_OK);
- mask_lo = tmp;
+ mask = tmp;
}
}
@@ -551,8 +552,8 @@ static void generic_get_mtrr(unsigned int reg, unsigned long *base,
* This works correctly if size is a power of two, i.e. a
* contiguous range:
*/
- *size = -mask_lo;
- *base = base_hi << (32 - PAGE_SHIFT) | base_lo >> PAGE_SHIFT;
+ *size = -mask;
+ *base = (u64)base_hi << (32 - PAGE_SHIFT) | base_lo >> PAGE_SHIFT;
*type = base_lo & 0xff;
out_put_cpu:
diff --git a/arch/x86/kernel/cpu/mtrr/main.c b/arch/x86/kernel/cpu/mtrr/main.c
index 726bf96..ca22b73 100644
--- a/arch/x86/kernel/cpu/mtrr/main.c
+++ b/arch/x86/kernel/cpu/mtrr/main.c
@@ -305,7 +305,8 @@ int mtrr_add_page(unsigned long base, unsigned long size,
return -EINVAL;
}
- if (base & size_or_mask || size & size_or_mask) {
+ if ((base | (base + size - 1)) >>
+ (boot_cpu_data.x86_phys_bits - PAGE_SHIFT)) {
pr_warning("mtrr: base or size exceeds the MTRR width\n");
return -EINVAL;
}
@@ -583,6 +584,7 @@ static struct syscore_ops mtrr_syscore_ops = {
int __initdata changed_by_mtrr_cleanup;
+#define SIZE_OR_MASK_BITS(n) (~((1ULL << ((n) - PAGE_SHIFT)) - 1))
/**
* mtrr_bp_init - initialize mtrrs on the boot CPU
*
@@ -600,7 +602,7 @@ void __init mtrr_bp_init(void)
if (cpu_has_mtrr) {
mtrr_if = &generic_mtrr_ops;
- size_or_mask = 0xff000000; /* 36 bits */
+ size_or_mask = SIZE_OR_MASK_BITS(36);
size_and_mask = 0x00f00000;
phys_addr = 36;
@@ -619,7 +621,7 @@ void __init mtrr_bp_init(void)
boot_cpu_data.x86_mask == 0x4))
phys_addr = 36;
- size_or_mask = ~((1ULL << (phys_addr - PAGE_SHIFT)) - 1);
+ size_or_mask = SIZE_OR_MASK_BITS(phys_addr);
size_and_mask = ~size_or_mask & 0xfffff00000ULL;
} else if (boot_cpu_data.x86_vendor == X86_VENDOR_CENTAUR &&
boot_cpu_data.x86 == 6) {
@@ -627,7 +629,7 @@ void __init mtrr_bp_init(void)
* VIA C* family have Intel style MTRRs,
* but don't support PAE
*/
- size_or_mask = 0xfff00000; /* 32 bits */
+ size_or_mask = SIZE_OR_MASK_BITS(32);
size_and_mask = 0;
phys_addr = 32;
}
@@ -637,21 +639,21 @@ void __init mtrr_bp_init(void)
if (cpu_has_k6_mtrr) {
/* Pre-Athlon (K6) AMD CPU MTRRs */
mtrr_if = mtrr_ops[X86_VENDOR_AMD];
- size_or_mask = 0xfff00000; /* 32 bits */
+ size_or_mask = SIZE_OR_MASK_BITS(32);
size_and_mask = 0;
}
break;
case X86_VENDOR_CENTAUR:
if (cpu_has_centaur_mcr) {
mtrr_if = mtrr_ops[X86_VENDOR_CENTAUR];
- size_or_mask = 0xfff00000; /* 32 bits */
+ size_or_mask = SIZE_OR_MASK_BITS(32);
size_and_mask = 0;
}
break;
case X86_VENDOR_CYRIX:
if (cpu_has_cyrix_arr) {
mtrr_if = mtrr_ops[X86_VENDOR_CYRIX];
- size_or_mask = 0xfff00000; /* 32 bits */
+ size_or_mask = SIZE_OR_MASK_BITS(32);
size_and_mask = 0;
}
break;
--
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