1 #ifndef __ASM_POWERPC_MMU_CONTEXT_H
2 #define __ASM_POWERPC_MMU_CONTEXT_H
3 #ifdef __KERNEL__
4 
5 #include <linux/kernel.h>
6 #include <linux/mm.h>
7 #include <linux/sched.h>
8 #include <linux/spinlock.h>
9 #include <asm/mmu.h>
10 #include <asm/cputable.h>
11 #include <asm-generic/mm_hooks.h>
12 #include <asm/cputhreads.h>
13 
14 /*
15  * Most if the context management is out of line
16  */
17 extern void mmu_context_init(void);
18 extern int init_new_context(struct task_struct *tsk, struct mm_struct *mm);
19 extern void destroy_context(struct mm_struct *mm);
20 
21 extern void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next);
22 extern void switch_stab(struct task_struct *tsk, struct mm_struct *mm);
23 extern void switch_slb(struct task_struct *tsk, struct mm_struct *mm);
24 extern void set_context(unsigned long id, pgd_t *pgd);
25 
26 /*
27  * switch_mm is the entry point called from the architecture independent
28  * code in kernel/sched.c
29  */
30 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
31 			     struct task_struct *tsk)
32 {
33 	/* Mark this context has been used on the new CPU */
34 	cpumask_set_cpu(smp_processor_id(), mm_cpumask(next));
35 
36 	/* 32-bit keeps track of the current PGDIR in the thread struct */
37 #ifdef CONFIG_PPC32
38 	tsk->thread.pgdir = next->pgd;
39 #endif /* CONFIG_PPC32 */
40 
41 	/* Nothing else to do if we aren't actually switching */
42 	if (prev == next)
43 		return;
44 
45 	/* We must stop all altivec streams before changing the HW
46 	 * context
47 	 */
48 #ifdef CONFIG_ALTIVEC
49 	if (cpu_has_feature(CPU_FTR_ALTIVEC))
50 		asm volatile ("dssall");
51 #endif /* CONFIG_ALTIVEC */
52 
53 	/* The actual HW switching method differs between the various
54 	 * sub architectures.
55 	 */
56 #ifdef CONFIG_PPC_STD_MMU_64
57 	if (cpu_has_feature(CPU_FTR_SLB))
58 		switch_slb(tsk, next);
59 	else
60 		switch_stab(tsk, next);
61 #else
62 	/* Out of line for now */
63 	switch_mmu_context(prev, next);
64 #endif
65 
66 }
67 
68 #define deactivate_mm(tsk,mm)	do { } while (0)
69 
70 /*
71  * After we have set current->mm to a new value, this activates
72  * the context for the new mm so we see the new mappings.
73  */
74 static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
75 {
76 	unsigned long flags;
77 
78 	local_irq_save(flags);
79 	switch_mm(prev, next, current);
80 	local_irq_restore(flags);
81 }
82 
83 /* We don't currently use enter_lazy_tlb() for anything */
84 static inline void enter_lazy_tlb(struct mm_struct *mm,
85 				  struct task_struct *tsk)
86 {
87 }
88 
89 #endif /* __KERNEL__ */
90 #endif /* __ASM_POWERPC_MMU_CONTEXT_H */
91