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@kernel.org>
Link: http://lkml.kernel.org/r/1371162815-29931-1-git-send-email-yinghai@kernel.org
Cc: <stable@vger.kernel.org>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
d5c78673b1