MN10300: Make the use of PIDR to mark TLB entries controllable

Make controllable the use of the PIDR register to mark TLB entries as belonging
to particular processes.

Signed-off-by: Akira Takeuchi <takeuchi.akr@jp.panasonic.com>
Signed-off-by: Kiyoshi Owada <owada.kiyoshi@jp.panasonic.com>
Signed-off-by: David Howells <dhowells@redhat.com>

1 files changed, 30 insertions, 29 deletions

diff --git a/arch/mn10300/include/asm/mmu_context.h b/arch/mn10300/include/asm/mmu_context.h
index 24d63f0f7377..5fb3648968ae 100644
--- a/arch/mn10300/include/asm/mmu_context.h
+++ b/arch/mn10300/include/asm/mmu_context.h
@@ -27,28 +27,22 @@
 #include <asm/tlbflush.h>
 #include <asm-generic/mm_hooks.h>
 
+#define MMU_CONTEXT_TLBPID_NR		256
 #define MMU_CONTEXT_TLBPID_MASK		0x000000ffUL
 #define MMU_CONTEXT_VERSION_MASK	0xffffff00UL
 #define MMU_CONTEXT_FIRST_VERSION	0x00000100UL
 #define MMU_NO_CONTEXT			0x00000000UL
-
-extern unsigned long mmu_context_cache[NR_CPUS];
-#define mm_context(mm)	(mm->context.tlbpid[smp_processor_id()])
+#define MMU_CONTEXT_TLBPID_LOCK_NR	0
 
 #define enter_lazy_tlb(mm, tsk)	do {} while (0)
 
-#ifdef CONFIG_SMP
-#define cpu_ran_vm(cpu, mm) \
-	cpumask_set_cpu((cpu), mm_cpumask(mm))
-#define cpu_maybe_ran_vm(cpu, mm) \
-	cpumask_test_and_set_cpu((cpu), mm_cpumask(mm))
-#else
-#define cpu_ran_vm(cpu, mm)		do {} while (0)
-#define cpu_maybe_ran_vm(cpu, mm)	true
-#endif /* CONFIG_SMP */
+#ifdef CONFIG_MN10300_TLB_USE_PIDR
+extern unsigned long mmu_context_cache[NR_CPUS];
+#define mm_context(mm)	(mm->context.tlbpid[smp_processor_id()])
 
-/*
- * allocate an MMU context
+/**
+ * allocate_mmu_context - Allocate storage for the arch-specific MMU data
+ * @mm: The userspace VM context being set up
  */
 static inline unsigned long allocate_mmu_context(struct mm_struct *mm)
 {
@@ -101,34 +95,41 @@ static inline int init_new_context(struct task_struct *tsk,
 }
 
 /*
- * destroy context related info for an mm_struct that is about to be put to
- * rest
- */
-#define destroy_context(mm)	do { } while (0)
-
-/*
  * after we have set current->mm to a new value, this activates the context for
  * the new mm so we see the new mappings.
  */
-static inline void activate_context(struct mm_struct *mm, int cpu)
+static inline void activate_context(struct mm_struct *mm)
 {
 	PIDR = get_mmu_context(mm) & MMU_CONTEXT_TLBPID_MASK;
 }
+#else  /* CONFIG_MN10300_TLB_USE_PIDR */
 
-/*
- * change between virtual memory sets
+#define init_new_context(tsk, mm)	(0)
+#define activate_context(mm)		local_flush_tlb()
+
+#endif /* CONFIG_MN10300_TLB_USE_PIDR */
+
+/**
+ * destroy_context - Destroy mm context information
+ * @mm: The MM being destroyed.
+ *
+ * Destroy context related info for an mm_struct that is about to be put to
+ * rest
+ */
+#define destroy_context(mm)	do {} while (0)
+
+/**
+ * switch_mm - Change between userspace virtual memory contexts
+ * @prev: The outgoing MM context.
+ * @next: The incoming MM context.
+ * @tsk: The incoming task.
  */
 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
 			     struct task_struct *tsk)
 {
-	int cpu = smp_processor_id();
-
 	if (prev != next) {
-		cpu_ran_vm(cpu, next);
-		activate_context(next, cpu);
 		PTBR = (unsigned long) next->pgd;
-	} else if (!cpu_maybe_ran_vm(cpu, next)) {
-		activate_context(next, cpu);
+		activate_context(next);
 	}
 }