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ARC: [SMP] TLB flush

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- Add mm_cpumask setting (aggregating only, unlike some other arches)
  used to restrict the TLB flush cross-calling

- cross-calling versions of TLB flush routines (thanks to Noam)

Signed-off-by: Noam Camus <noamc@ezchip.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
This commit is contained in:
Vineet Gupta
2013-10-27 14:49:02 +05:30
parent 63eca94ca2
commit 5ea72a9026
4 changed files with 99 additions and 3 deletions
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arch/arc/include/asm/mmu_context.h
+16 -1
View File
@@ -80,7 +80,7 @@ static inline void get_new_mmu_context(struct mm_struct *mm)
/* move to new ASID and handle rollover */
if (unlikely(!(++asid_cpu(cpu) & MM_CTXT_ASID_MASK))) {
flush_tlb_all();
local_flush_tlb_all();
/*
* Above checke for rollover of 8 bit ASID in 32 bit container.
@@ -131,6 +131,21 @@ static inline void destroy_context(struct mm_struct *mm)
static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
struct task_struct *tsk)
{
const int cpu = smp_processor_id();
/*
* Note that the mm_cpumask is "aggregating" only, we don't clear it
* for the switched-out task, unlike some other arches.
* It is used to enlist cpus for sending TLB flush IPIs and not sending
* it to CPUs where a task once ran-on, could cause stale TLB entry
* re-use, specially for a multi-threaded task.
* e.g. T1 runs on C1, migrates to C3. T2 running on C2 munmaps.
* For a non-aggregating mm_cpumask, IPI not sent C1, and if T1
* were to re-migrate to C1, it could access the unmapped region
* via any existing stale TLB entries.
*/
cpumask_set_cpu(cpu, mm_cpumask(next));
#ifndef CONFIG_SMP
/* PGD cached in MMU reg to avoid 3 mem lookups: task->mm->pgd */
write_aux_reg(ARC_REG_SCRATCH_DATA0, next->pgd);
arch/arc/include/asm/tlbflush.h
+9 -2
View File
@@ -18,11 +18,18 @@ void local_flush_tlb_kernel_range(unsigned long start, unsigned long end);
void local_flush_tlb_range(struct vm_area_struct *vma,
unsigned long start, unsigned long end);
/* XXX: Revisit for SMP */
#ifndef CONFIG_SMP
#define flush_tlb_range(vma, s, e) local_flush_tlb_range(vma, s, e)
#define flush_tlb_page(vma, page) local_flush_tlb_page(vma, page)
#define flush_tlb_kernel_range(s, e) local_flush_tlb_kernel_range(s, e)
#define flush_tlb_all() local_flush_tlb_all()
#define flush_tlb_mm(mm) local_flush_tlb_mm(mm)
#else
extern void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
unsigned long end);
extern void flush_tlb_page(struct vm_area_struct *vma, unsigned long page);
extern void flush_tlb_kernel_range(unsigned long start, unsigned long end);
extern void flush_tlb_all(void);
extern void flush_tlb_mm(struct mm_struct *mm);
#endif /* CONFIG_SMP */
#endif