32 lines
1.2 KiB
Diff
32 lines
1.2 KiB
Diff
From: James Hogan <james.hogan@imgtec.com>
|
|
Date: Fri, 4 Mar 2016 10:10:51 +0000
|
|
Subject: [PATCH] MIPS: smp.c: Fix uninitialised temp_foreign_map
|
|
|
|
When calculate_cpu_foreign_map() recalculates the cpu_foreign_map
|
|
cpumask it uses the local variable temp_foreign_map without initialising
|
|
it to zero. Since the calculation only ever sets bits in this cpumask
|
|
any existing bits at that memory location will remain set and find their
|
|
way into cpu_foreign_map too. This could potentially lead to cache
|
|
operations suboptimally doing smp calls to multiple VPEs in the same
|
|
core, even though the VPEs share primary caches.
|
|
|
|
Therefore initialise temp_foreign_map using cpumask_clear() before use.
|
|
|
|
Fixes: cccf34e9411c ("MIPS: c-r4k: Fix cache flushing for MT cores")
|
|
Signed-off-by: James Hogan <james.hogan@imgtec.com>
|
|
Cc: Ralf Baechle <ralf@linux-mips.org>
|
|
Cc: Paul Burton <paul.burton@imgtec.com>
|
|
Cc: linux-mips@linux-mips.org
|
|
---
|
|
|
|
--- a/arch/mips/kernel/smp.c
|
|
+++ b/arch/mips/kernel/smp.c
|
|
@@ -121,6 +121,7 @@ static inline void calculate_cpu_foreign
|
|
cpumask_t temp_foreign_map;
|
|
|
|
/* Re-calculate the mask */
|
|
+ cpumask_clear(&temp_foreign_map);
|
|
for_each_online_cpu(i) {
|
|
core_present = 0;
|
|
for_each_cpu(k, &temp_foreign_map)
|