Patch "sparc64: add per-cpu mm of secondary contexts" has been added to the 4.4-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    sparc64: add per-cpu mm of secondary contexts

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     sparc64-add-per-cpu-mm-of-secondary-contexts.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From foo@baz Thu Jun  8 09:20:28 CEST 2017
From: Pavel Tatashin <pasha.tatashin@oracle.com>
Date: Wed, 31 May 2017 11:25:23 -0400
Subject: sparc64: add per-cpu mm of secondary contexts

From: Pavel Tatashin <pasha.tatashin@oracle.com>


[ Upstream commit 7a5b4bbf49fe86ce77488a70c5dccfe2d50d7a2d ]

The new wrap is going to use information from this array to figure out
mm's that currently have valid secondary contexts setup.

Signed-off-by: Pavel Tatashin <pasha.tatashin@oracle.com>
Reviewed-by: Bob Picco <bob.picco@oracle.com>
Reviewed-by: Steven Sistare <steven.sistare@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 arch/sparc/include/asm/mmu_context_64.h |    5 +++--
 arch/sparc/mm/init_64.c                 |    1 +
 2 files changed, 4 insertions(+), 2 deletions(-)

--- a/arch/sparc/include/asm/mmu_context_64.h
+++ b/arch/sparc/include/asm/mmu_context_64.h
@@ -17,6 +17,7 @@ extern spinlock_t ctx_alloc_lock;
 extern unsigned long tlb_context_cache;
 extern unsigned long mmu_context_bmap[];
 
+DECLARE_PER_CPU(struct mm_struct *, per_cpu_secondary_mm);
 void get_new_mmu_context(struct mm_struct *mm);
 #ifdef CONFIG_SMP
 void smp_new_mmu_context_version(void);
@@ -74,8 +75,9 @@ void __flush_tlb_mm(unsigned long, unsig
 static inline void switch_mm(struct mm_struct *old_mm, struct mm_struct *mm, struct task_struct *tsk)
 {
 	unsigned long ctx_valid, flags;
-	int cpu;
+	int cpu = smp_processor_id();
 
+	per_cpu(per_cpu_secondary_mm, cpu) = mm;
 	if (unlikely(mm == &init_mm))
 		return;
 
@@ -121,7 +123,6 @@ static inline void switch_mm(struct mm_s
 	 * for the first time, we must flush that context out of the
 	 * local TLB.
 	 */
-	cpu = smp_processor_id();
 	if (!ctx_valid || !cpumask_test_cpu(cpu, mm_cpumask(mm))) {
 		cpumask_set_cpu(cpu, mm_cpumask(mm));
 		__flush_tlb_mm(CTX_HWBITS(mm->context),
--- a/arch/sparc/mm/init_64.c
+++ b/arch/sparc/mm/init_64.c
@@ -660,6 +660,7 @@ unsigned long tlb_context_cache = CTX_FI
 #define MAX_CTX_NR	(1UL << CTX_NR_BITS)
 #define CTX_BMAP_SLOTS	BITS_TO_LONGS(MAX_CTX_NR)
 DECLARE_BITMAP(mmu_context_bmap, MAX_CTX_NR);
+DEFINE_PER_CPU(struct mm_struct *, per_cpu_secondary_mm) = {0};
 
 /* Caller does TLB context flushing on local CPU if necessary.
  * The caller also ensures that CTX_VALID(mm->context) is false.


Patches currently in stable-queue which might be from pasha.tatashin@oracle.com are

queue-4.4/sparc64-new-context-wrap.patch
queue-4.4/sparc64-combine-activate_mm-and-switch_mm.patch
queue-4.4/sparc64-add-per-cpu-mm-of-secondary-contexts.patch
queue-4.4/sparc64-reset-mm-cpumask-after-wrap.patch
queue-4.4/sparc64-redefine-first-version.patch
queue-4.4/sparc64-delete-old-wrap-code.patch