kernel: replace SMP cacheflush fix with some patches from linux-mti.git

Signed-off-by: Felix Fietkau <nbd@nbd.name>

1 files changed, 37 insertions, 0 deletions

diff --git a/target/linux/generic/patches-4.4/091-MIPS-c-r4k-Exclude-sibling-CPUs-in-SMP-calls.patch b/target/linux/generic/patches-4.4/091-MIPS-c-r4k-Exclude-sibling-CPUs-in-SMP-calls.patch
new file mode 100644
index 0000000000..8d5030c84b
--- /dev/null
+++ b/target/linux/generic/patches-4.4/091-MIPS-c-r4k-Exclude-sibling-CPUs-in-SMP-calls.patch
@@ -0,0 +1,37 @@
+From: James Hogan <james.hogan@imgtec.com>
+Date: Thu, 3 Mar 2016 21:30:42 +0000
+Subject: [PATCH] MIPS: c-r4k: Exclude sibling CPUs in SMP calls
+
+When performing SMP calls to foreign cores, exclude sibling CPUs from
+the provided map, as we already handle the local core on the current
+CPU. This prevents an IPI call from for example core 0, VPE 1 to VPE 0
+on the same core.
+
+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/mm/c-r4k.c
++++ b/arch/mips/mm/c-r4k.c
+@@ -96,8 +96,17 @@ static inline void r4k_on_each_cpu(unsig
+ 				   void (*func) (void *info), void *info)
+ {
+ 	preempt_disable();
+-	if (r4k_op_needs_ipi(type))
+-		smp_call_function_many(&cpu_foreign_map, func, info, 1);
++	/* cpu_foreign_map and cpu_sibling_map[] undeclared when !CONFIG_SMP */
++#ifdef CONFIG_SMP
++	if (r4k_op_needs_ipi(type)) {
++		struct cpumask mask;
++
++		/* exclude sibling CPUs */
++		cpumask_andnot(&mask, &cpu_foreign_map,
++			       &cpu_sibling_map[smp_processor_id()]);
++		smp_call_function_many(&mask, func, info, 1);
++	}
++#endif
+ 	func(info);
+ 	preempt_enable();
+ }