Messages in this thread Patch in this message | | | From | Juergen Gross <> | Subject | [PATCH 6/6] x86/mtrr: drop sanity check in mtrr_type_lookup_fixed() | Date | Tue, 7 Feb 2023 08:29:02 +0100 |
| |
mtrr_type_lookup_fixed() contains a sanity check for the case it is being called with a start address above 1 MB. As it is static and it is called only iff the start address is below 1MB, this sanity check can be dropped.
This will remove the last case where mtrr_type_lookup() can return MTRR_TYPE_INVALID, so adjust the comment in include/uapi/asm/mtrr.h.
Note that removing the MTRR_TYPE_INVALID #define from that header could break user code, so it has to stay.
Signed-off-by: Juergen Gross <jgross@suse.com> --- arch/x86/include/uapi/asm/mtrr.h | 6 +++--- arch/x86/kernel/cpu/mtrr/generic.c | 6 +----- 2 files changed, 4 insertions(+), 8 deletions(-)
diff --git a/arch/x86/include/uapi/asm/mtrr.h b/arch/x86/include/uapi/asm/mtrr.h index 376563f2bac1..4aa05c2ffa78 100644 --- a/arch/x86/include/uapi/asm/mtrr.h +++ b/arch/x86/include/uapi/asm/mtrr.h @@ -115,9 +115,9 @@ struct mtrr_state_type { #define MTRR_NUM_TYPES 7 /* - * Invalid MTRR memory type. mtrr_type_lookup() returns this value when - * MTRRs are disabled. Note, this value is allocated from the reserved - * values (0x7-0xff) of the MTRR memory types. + * Invalid MTRR memory type. No longer used outside of MTRR code. + * Note, this value is allocated from the reserved values (0x7-0xff) of + * the MTRR memory types. */ #define MTRR_TYPE_INVALID 0xff diff --git a/arch/x86/kernel/cpu/mtrr/generic.c b/arch/x86/kernel/cpu/mtrr/generic.c index c749ec4436a1..c17cb00aac6a 100644 --- a/arch/x86/kernel/cpu/mtrr/generic.c +++ b/arch/x86/kernel/cpu/mtrr/generic.c @@ -114,16 +114,12 @@ static int check_type_overlap(u8 *prev, u8 *curr) * 0xC0000 - 0xFFFFF : This range is divided into sixty-four 4KB sub-ranges * * Return Values: - * MTRR_TYPE_(type) - Matched memory type - * MTRR_TYPE_INVALID - Unmatched + * MTRR_TYPE_(type) - Memory type */ static u8 mtrr_type_lookup_fixed(u64 start, u64 end) { int idx; - if (start >= 0x100000) - return MTRR_TYPE_INVALID; - /* 0x0 - 0x7FFFF */ if (start < 0x80000) { idx = 0; -- 2.35.3
| |