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| author | Raul E Rangel <rrangel@chromium.org> | 2020-04-27 15:38:58 -0600 |
|---|---|---|
| committer | Aaron Durbin <adurbin@chromium.org> | 2020-05-01 15:42:01 +0000 |
| commit | 3e42ee05d86c1de3ed23dddf08fd8e6451bdea92 (patch) | |
| tree | 2b6941b396b30cbbb20ab2865cf738b6576a1320 /src/cpu/x86 | |
| parent | e4c81bcca59e94c71f7acf48c060da827afeb15a (diff) | |
| download | coreboot-3e42ee05d86c1de3ed23dddf08fd8e6451bdea92.tar.xz | |
cpu/x86/mtrr/earlymtrr: Validate MTRR arguments
The AMD64 Architecture Programmer's Manual, Volume 2: Systems
Programming says the following about variable MTRRs:
Variable Range Size and Alignment.
The size and alignment of variable memory-ranges (MTRRs) and I/O ranges
(IORRs) are restricted as follows:
* The boundary on which a variable range is aligned must be equal to the
range size. For example, a memory range of 16 Mbytes must be aligned on a
16-Mbyte boundary (i.e., naturally aligned).
* The range size must be a power of 2 (2^n , 52 > n > 11), with a minimum
allowable size of 4 Kbytes. For example, 4 Mbytes and 8 Mbytes are
allowable memory range sizes, but 6 Mbytes is not allowable.
Print out errors if these conditions are violated. I didn't assert since
`set_var_mtrr` can be used in boot block before the serial console is
enabled.
BUG=b:147042464
TEST=Boot trembyle and see MTRR errors:
MTRR Error: base 0xcc800000 must be aligned to size 0x1000000
Signed-off-by: Raul E Rangel <rrangel@chromium.org>
Change-Id: I8b8c734c7599bd89cf9f212ed43c2dd5b2c8ba7b
Reviewed-on: https://review.coreboot.org/c/coreboot/+/40762
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Diffstat (limited to 'src/cpu/x86')
| -rw-r--r-- | src/cpu/x86/mtrr/earlymtrr.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/src/cpu/x86/mtrr/earlymtrr.c b/src/cpu/x86/mtrr/earlymtrr.c index e8608fd9cc..f96b05061f 100644 --- a/src/cpu/x86/mtrr/earlymtrr.c +++ b/src/cpu/x86/mtrr/earlymtrr.c @@ -4,6 +4,8 @@ #include <cpu/cpu.h> #include <cpu/x86/mtrr.h> #include <cpu/x86/msr.h> +#include <console/console.h> +#include <commonlib/bsd/helpers.h> /* Get first available variable MTRR. * Returns var# if available, else returns -1. @@ -34,6 +36,15 @@ void set_var_mtrr( /* Bit Bit 32-35 of MTRRphysMask should be set to 1 */ /* FIXME: It only support 4G less range */ msr_t basem, maskm; + + if (!IS_POWER_OF_2(size)) + printk(BIOS_ERR, "MTRR Error: size %#x is not a power of two\n", size); + if (size < 4 * KiB) + printk(BIOS_ERR, "MTRR Error: size %#x smaller than 4KiB\n", size); + if (base % size != 0) + printk(BIOS_ERR, "MTRR Error: base %#x must be aligned to size %#x\n", base, + size); + basem.lo = base | type; basem.hi = 0; wrmsr(MTRR_PHYS_BASE(reg), basem); |