diff options
| author | Juergen Gross <jgross@suse.com> | 2023-05-02 14:09:25 +0200 |
|---|---|---|
| committer | Borislav Petkov (AMD) <bp@alien8.de> | 2023-06-01 15:04:33 +0200 |
| commit | 1ca12099040fec8c6bbcd9fabf37f04ac0d08e48 (patch) | |
| tree | 253ef6988f5316f425f958d6881043cdd30ac8b4 /arch/x86/kernel/cpu/mtrr/generic.c | |
| parent | 961c6a4326643e6588352b7f1f5d77364415386f (diff) | |
x86/mtrr: Add get_effective_type() service function
Add a service function for obtaining the effective cache mode of
overlapping MTRR registers.
Make use of that function in check_type_overlap().
Signed-off-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20230502120931.20719-11-jgross@suse.com
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Diffstat (limited to 'arch/x86/kernel/cpu/mtrr/generic.c')
| -rw-r--r-- | arch/x86/kernel/cpu/mtrr/generic.c | 39 |
1 files changed, 19 insertions, 20 deletions
diff --git a/arch/x86/kernel/cpu/mtrr/generic.c b/arch/x86/kernel/cpu/mtrr/generic.c index 4d8ca6234bbf..b9442717977f 100644 --- a/arch/x86/kernel/cpu/mtrr/generic.c +++ b/arch/x86/kernel/cpu/mtrr/generic.c @@ -80,31 +80,30 @@ static u64 get_mtrr_size(u64 mask) return size; } +static u8 get_effective_type(u8 type1, u8 type2) +{ + if (type1 == MTRR_TYPE_UNCACHABLE || type2 == MTRR_TYPE_UNCACHABLE) + return MTRR_TYPE_UNCACHABLE; + + if ((type1 == MTRR_TYPE_WRBACK && type2 == MTRR_TYPE_WRTHROUGH) || + (type1 == MTRR_TYPE_WRTHROUGH && type2 == MTRR_TYPE_WRBACK)) + return MTRR_TYPE_WRTHROUGH; + + if (type1 != type2) + return MTRR_TYPE_UNCACHABLE; + + return type1; +} + /* * Check and return the effective type for MTRR-MTRR type overlap. - * Returns 1 if the effective type is UNCACHEABLE, else returns 0 + * Returns true if the effective type is UNCACHEABLE, else returns false */ -static int check_type_overlap(u8 *prev, u8 *curr) +static bool check_type_overlap(u8 *prev, u8 *curr) { - if (*prev == MTRR_TYPE_UNCACHABLE || *curr == MTRR_TYPE_UNCACHABLE) { - *prev = MTRR_TYPE_UNCACHABLE; - *curr = MTRR_TYPE_UNCACHABLE; - return 1; - } - - if ((*prev == MTRR_TYPE_WRBACK && *curr == MTRR_TYPE_WRTHROUGH) || - (*prev == MTRR_TYPE_WRTHROUGH && *curr == MTRR_TYPE_WRBACK)) { - *prev = MTRR_TYPE_WRTHROUGH; - *curr = MTRR_TYPE_WRTHROUGH; - } + *prev = *curr = get_effective_type(*curr, *prev); - if (*prev != *curr) { - *prev = MTRR_TYPE_UNCACHABLE; - *curr = MTRR_TYPE_UNCACHABLE; - return 1; - } - - return 0; + return *prev == MTRR_TYPE_UNCACHABLE; } /** |