[PATCH 4.9 019/119] sparc64: add per-cpu mm of secondary contexts

From: Greg Kroah-Hartman
Date: Mon Jun 12 2017 - 11:33:33 EST


4.9-stable review patch. If anyone has any objections, please let me know.

------------------

From: Pavel Tatashin <pasha.tatashin@xxxxxxxxxx>


[ 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@xxxxxxxxxx>
Reviewed-by: Bob Picco <bob.picco@xxxxxxxxxx>
Reviewed-by: Steven Sistare <steven.sistare@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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
@@ -662,6 +662,7 @@ 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.