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Diffstat (limited to 'arch/arm/mm/context.c')
-rw-r--r--arch/arm/mm/context.c57
1 files changed, 28 insertions, 29 deletions
diff --git a/arch/arm/mm/context.c b/arch/arm/mm/context.c
index ee9bb363d606..806cc4f63516 100644
--- a/arch/arm/mm/context.c
+++ b/arch/arm/mm/context.c
@@ -18,30 +18,39 @@
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
#ifdef CONFIG_ARM_LPAE
-#define cpu_set_asid(asid) { \
- unsigned long ttbl, ttbh; \
- asm volatile( \
- " mrrc p15, 0, %0, %1, c2 @ read TTBR0\n" \
- " mov %1, %2, lsl #(48 - 32) @ set ASID\n" \
- " mcrr p15, 0, %0, %1, c2 @ set TTBR0\n" \
- : "=&r" (ttbl), "=&r" (ttbh) \
- : "r" (asid & ~ASID_MASK)); \
+void cpu_set_reserved_ttbr0(void)
+{
+ unsigned long ttbl = __pa(swapper_pg_dir);
+ unsigned long ttbh = 0;
+
+ /*
+ * Set TTBR0 to swapper_pg_dir which contains only global entries. The
+ * ASID is set to 0.
+ */
+ asm volatile(
+ " mcrr p15, 0, %0, %1, c2 @ set TTBR0\n"
+ :
+ : "r" (ttbl), "r" (ttbh));
+ isb();
}
#else
-#define cpu_set_asid(asid) \
- asm(" mcr p15, 0, %0, c13, c0, 1\n" : : "r" (asid))
+void cpu_set_reserved_ttbr0(void)
+{
+ u32 ttb;
+ /* Copy TTBR1 into TTBR0 */
+ asm volatile(
+ " mrc p15, 0, %0, c2, c0, 1 @ read TTBR1\n"
+ " mcr p15, 0, %0, c2, c0, 0 @ set TTBR0\n"
+ : "=r" (ttb));
+ isb();
+}
#endif
/*
* We fork()ed a process, and we need a new context for the child
- * to run in. We reserve version 0 for initial tasks so we will
- * always allocate an ASID. The ASID 0 is reserved for the TTBR
- * register changing sequence.
+ * to run in.
*/
void __init_new_context(struct task_struct *tsk, struct mm_struct *mm)
{
@@ -51,9 +60,7 @@ void __init_new_context(struct task_struct *tsk, struct mm_struct *mm)
static void flush_context(void)
{
- /* set the reserved ASID before flushing the TLB */
- cpu_set_asid(0);
- isb();
+ cpu_set_reserved_ttbr0();
local_flush_tlb_all();
if (icache_is_vivt_asid_tagged()) {
__flush_icache_all();
@@ -98,14 +105,7 @@ 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 + 1;
@@ -114,8 +114,7 @@ static void reset_context(void *info)
set_mm_context(mm, asid);
/* set the new ASID */
- cpu_set_asid(mm->context.id);
- isb();
+ cpu_switch_mm(mm->pgd, mm);
}
#else