powerpc/mm: Abstraction for switch_mmu_context()

How we switch MMU context differs between hash and radix. For hash we
need to switch the SLB details and for radix we need to switch the PID
SPR.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/include/asm/mmu_context.h

@@ -33,16 +33,23 @@ extern long mm_iommu_ua_to_hpa(struct mm_iommu_table_group_mem_t *mem,
 extern long mm_iommu_mapped_inc(struct mm_iommu_table_group_mem_t *mem);
 extern void mm_iommu_mapped_dec(struct mm_iommu_table_group_mem_t *mem);
 #endif
-
-extern void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next);
 extern void switch_slb(struct task_struct *tsk, struct mm_struct *mm);
 extern void set_context(unsigned long id, pgd_t *pgd);
 
 #ifdef CONFIG_PPC_BOOK3S_64
+static inline void switch_mmu_context(struct mm_struct *prev,
+				      struct mm_struct *next,
+				      struct task_struct *tsk)
+{
+	return switch_slb(tsk, next);
+}
+
 extern int __init_new_context(void);
 extern void __destroy_context(int context_id);
 static inline void mmu_context_init(void) { }
 #else
+extern void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
+			       struct task_struct *tsk);
 extern unsigned long __init_new_context(void);
 extern void __destroy_context(unsigned long context_id);
 extern void mmu_context_init(void);
@@ -88,17 +95,11 @@ static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
 	if (cpu_has_feature(CPU_FTR_ALTIVEC))
 		asm volatile ("dssall");
 #endif /* CONFIG_ALTIVEC */
-
-	/* The actual HW switching method differs between the various
-	 * sub architectures.
+	/*
+	 * The actual HW switching method differs between the various
+	 * sub architectures. Out of line for now
 	 */
-#ifdef CONFIG_PPC_STD_MMU_64
-	switch_slb(tsk, next);
-#else
-	/* Out of line for now */
-	switch_mmu_context(prev, next);
-#endif
-
+	switch_mmu_context(prev, next, tsk);
 }
 
 #define deactivate_mm(tsk,mm)	do { } while (0)

arch/powerpc/kernel/swsusp.c

@@ -31,6 +31,6 @@ void save_processor_state(void)
 void restore_processor_state(void)
 {
 #ifdef CONFIG_PPC32
-	switch_mmu_context(current->active_mm, current->active_mm);
+	switch_mmu_context(current->active_mm, current->active_mm, NULL);
 #endif
 }

arch/powerpc/mm/mmu_context_nohash.c

@@ -226,7 +226,8 @@ static void context_check_map(void)
 static void context_check_map(void) { }
 #endif
 
-void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next)
+void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next,
+			struct task_struct *tsk)
 {
 	unsigned int i, id, cpu = smp_processor_id();
 	unsigned long *map;

drivers/cpufreq/pmac32-cpufreq.c

@@ -298,7 +298,7 @@ static int pmu_set_cpu_speed(int low_speed)
  		_set_L3CR(save_l3cr);
 
 	/* Restore userland MMU context */
-	switch_mmu_context(NULL, current->active_mm);
+	switch_mmu_context(NULL, current->active_mm, NULL);
 
 #ifdef DEBUG_FREQ
 	printk(KERN_DEBUG "HID1, after: %x\n", mfspr(SPRN_HID1));

drivers/macintosh/via-pmu.c

@@ -1851,7 +1851,7 @@ static int powerbook_sleep_grackle(void)
  		_set_L2CR(save_l2cr);
 	
 	/* Restore userland MMU context */
-	switch_mmu_context(NULL, current->active_mm);
+	switch_mmu_context(NULL, current->active_mm, NULL);
 
 	/* Power things up */
 	pmu_unlock();
@@ -1940,7 +1940,7 @@ powerbook_sleep_Core99(void)
  		_set_L3CR(save_l3cr);
 	
 	/* Restore userland MMU context */
-	switch_mmu_context(NULL, current->active_mm);
+	switch_mmu_context(NULL, current->active_mm, NULL);
 
 	/* Tell PMU we are ready */
 	pmu_unlock();