[RFC PATCH 5/6] ARM: Remove current_mm per-cpu variable
From: catalin.marinas@arm.com (Catalin Marinas)
Date: 2011-11-29 12:22:59
Also in:
lkml
Subsystem:
arm port, the rest · Maintainers:
Russell King, Linus Torvalds
The current_mm variable was used to store the new mm between the switch_mm() and switch_to() calls where an IPI to reset the context could have set the wrong mm. Since the interrupts are disabled during context switch, there is no need for this variable, current->active_mm already points to the current mm when interrupts are re-enabled. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Russell King <redacted> --- arch/arm/include/asm/mmu_context.h | 7 ------- arch/arm/mm/context.c | 12 +----------- 2 files changed, 1 insertions(+), 18 deletions(-)
diff --git a/arch/arm/include/asm/mmu_context.h b/arch/arm/include/asm/mmu_context.h
index 3e4b219..56710d8 100644
--- a/arch/arm/include/asm/mmu_context.h
+++ b/arch/arm/include/asm/mmu_context.h@@ -42,9 +42,6 @@ void __check_kvm_seq(struct mm_struct *mm); #define ASID_FIRST_VERSION (1 << ASID_BITS) extern unsigned int cpu_last_asid; -#ifdef CONFIG_SMP -DECLARE_PER_CPU(struct mm_struct *, current_mm); -#endif void __init_new_context(struct task_struct *tsk, struct mm_struct *mm); void __new_context(struct mm_struct *mm);
@@ -154,10 +151,6 @@ switch_mm(struct mm_struct *prev, struct mm_struct *next, __flush_icache_all(); #endif if (!cpumask_test_and_set_cpu(cpu, mm_cpumask(next)) || prev != next) { -#ifdef CONFIG_SMP - struct mm_struct **crt_mm = &per_cpu(current_mm, cpu); - *crt_mm = next; -#endif check_and_switch_context(next, tsk); if (cache_is_vivt()) cpumask_clear_cpu(cpu, mm_cpumask(prev));
diff --git a/arch/arm/mm/context.c b/arch/arm/mm/context.c
index d80aef0..cbca8a4 100644
--- a/arch/arm/mm/context.c
+++ b/arch/arm/mm/context.c@@ -18,9 +18,6 @@ static DEFINE_RAW_SPINLOCK(cpu_asid_lock); unsigned int cpu_last_asid = ASID_FIRST_VERSION; -#ifdef CONFIG_SMP -DEFINE_PER_CPU(struct mm_struct *, current_mm); -#endif void cpu_set_reserved_ttbr0(void) {
@@ -90,14 +87,7 @@ static void reset_context(void *info) { unsigned int asid; unsigned int cpu = smp_processor_id(); - struct mm_struct *mm = per_cpu(current_mm, cpu); - - /* - * Check if a current_mm was set on this CPU as it might still - * be in the early booting stages and using the reserved ASID. - */ - if (!mm) - return; + struct mm_struct *mm = current->active_mm; smp_rmb(); asid = cpu_last_asid + cpu;