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-rw-r--r--arch/arm/mm/context.c10
-rw-r--r--include/asm-arm/mmu_context.h8
2 files changed, 11 insertions, 7 deletions
diff --git a/arch/arm/mm/context.c b/arch/arm/mm/context.c
index 9da43a0fdcdf..930c04c4f53c 100644
--- a/arch/arm/mm/context.c
+++ b/arch/arm/mm/context.c
@@ -14,7 +14,8 @@
14#include <asm/mmu_context.h> 14#include <asm/mmu_context.h>
15#include <asm/tlbflush.h> 15#include <asm/tlbflush.h>
16 16
17unsigned int cpu_last_asid = { 1 << ASID_BITS }; 17static DEFINE_SPINLOCK(cpu_asid_lock);
18unsigned int cpu_last_asid = ASID_FIRST_VERSION;
18 19
19/* 20/*
20 * We fork()ed a process, and we need a new context for the child 21 * We fork()ed a process, and we need a new context for the child
@@ -31,15 +32,16 @@ void __new_context(struct mm_struct *mm)
31{ 32{
32 unsigned int asid; 33 unsigned int asid;
33 34
35 spin_lock(&cpu_asid_lock);
34 asid = ++cpu_last_asid; 36 asid = ++cpu_last_asid;
35 if (asid == 0) 37 if (asid == 0)
36 asid = cpu_last_asid = 1 << ASID_BITS; 38 asid = cpu_last_asid = ASID_FIRST_VERSION;
37 39
38 /* 40 /*
39 * If we've used up all our ASIDs, we need 41 * If we've used up all our ASIDs, we need
40 * to start a new version and flush the TLB. 42 * to start a new version and flush the TLB.
41 */ 43 */
42 if ((asid & ~ASID_MASK) == 0) { 44 if (unlikely((asid & ~ASID_MASK) == 0)) {
43 asid = ++cpu_last_asid; 45 asid = ++cpu_last_asid;
44 /* set the reserved ASID before flushing the TLB */ 46 /* set the reserved ASID before flushing the TLB */
45 asm("mcr p15, 0, %0, c13, c0, 1 @ set reserved context ID\n" 47 asm("mcr p15, 0, %0, c13, c0, 1 @ set reserved context ID\n"
@@ -48,6 +50,8 @@ void __new_context(struct mm_struct *mm)
48 isb(); 50 isb();
49 flush_tlb_all(); 51 flush_tlb_all();
50 } 52 }
53 spin_unlock(&cpu_asid_lock);
51 54
55 mm->cpu_vm_mask = cpumask_of_cpu(smp_processor_id());
52 mm->context.id = asid; 56 mm->context.id = asid;
53} 57}
diff --git a/include/asm-arm/mmu_context.h b/include/asm-arm/mmu_context.h
index f8755c818b54..4981ad419198 100644
--- a/include/asm-arm/mmu_context.h
+++ b/include/asm-arm/mmu_context.h
@@ -36,8 +36,9 @@ void __check_kvm_seq(struct mm_struct *mm);
36 * The context ID is used by debuggers and trace logic, and 36 * The context ID is used by debuggers and trace logic, and
37 * should be unique within all running processes. 37 * should be unique within all running processes.
38 */ 38 */
39#define ASID_BITS 8 39#define ASID_BITS 8
40#define ASID_MASK ((~0) << ASID_BITS) 40#define ASID_MASK ((~0) << ASID_BITS)
41#define ASID_FIRST_VERSION (1 << ASID_BITS)
41 42
42extern unsigned int cpu_last_asid; 43extern unsigned int cpu_last_asid;
43 44
@@ -96,8 +97,7 @@ switch_mm(struct mm_struct *prev, struct mm_struct *next,
96#ifdef CONFIG_MMU 97#ifdef CONFIG_MMU
97 unsigned int cpu = smp_processor_id(); 98 unsigned int cpu = smp_processor_id();
98 99
99 if (prev != next) { 100 if (!cpu_test_and_set(cpu, next->cpu_vm_mask) || prev != next) {
100 cpu_set(cpu, next->cpu_vm_mask);
101 check_context(next); 101 check_context(next);
102 cpu_switch_mm(next->pgd, next); 102 cpu_switch_mm(next->pgd, next);
103 if (cache_is_vivt()) 103 if (cache_is_vivt())