diff options
authorSuravee Suthikulpanit <suravee.suthikulpanit@amd.com>2018-06-13 13:43:10 -0500
committerThomas Gleixner <tglx@linutronix.de>2018-06-22 21:21:49 +0200
commit964d978433a4b9aa1368ff71227ca0027dd1e32f (patch)
parent7731b8bc94e599c9a79e428f3359ff2c34b7576a (diff)
x86/CPU/AMD: Fix LLC ID bit-shift calculation
The current logic incorrectly calculates the LLC ID from the APIC ID. Unless specified otherwise, the LLC ID should be calculated by removing the Core and Thread ID bits from the least significant end of the APIC ID. For more info, see "ApicId Enumeration Requirements" in any Fam17h PPR document. [ bp: Improve commit message. ] Fixes: 68091ee7ac3c ("Calculate last level cache ID from number of sharing threads") Signed-off-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com> Signed-off-by: Borislav Petkov <bp@suse.de> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1528915390-30533-1-git-send-email-suravee.suthikulpanit@amd.com
1 files changed, 1 insertions, 1 deletions
diff --git a/arch/x86/kernel/cpu/cacheinfo.c b/arch/x86/kernel/cpu/cacheinfo.c
index 38354c66df81..0c5fcbd998cf 100644
--- a/arch/x86/kernel/cpu/cacheinfo.c
+++ b/arch/x86/kernel/cpu/cacheinfo.c
@@ -671,7 +671,7 @@ void cacheinfo_amd_init_llc_id(struct cpuinfo_x86 *c, int cpu, u8 node_id)
num_sharing_cache = ((eax >> 14) & 0xfff) + 1;
if (num_sharing_cache) {
- int bits = get_count_order(num_sharing_cache) - 1;
+ int bits = get_count_order(num_sharing_cache);
per_cpu(cpu_llc_id, cpu) = c->apicid >> bits;