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 int init_new_context(struct task_struct *tsk, struct mm_struct *mm);
18 extern void destroy_context(struct mm_struct *mm);
19 
20 extern void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next);
21 extern void switch_stab(struct task_struct *tsk, struct mm_struct *mm);
22 extern void switch_slb(struct task_struct *tsk, struct mm_struct *mm);
23 extern void set_context(unsigned long id, pgd_t *pgd);
24 
25 #ifdef CONFIG_PPC_BOOK3S_64
26 static inline void mmu_context_init(void) { }
27 #else
28 extern void mmu_context_init(void);
29 #endif
30 
31 /*
32  * switch_mm is the entry point called from the architecture independent
33  * code in kernel/sched.c
34  */
35 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
36 			     struct task_struct *tsk)
37 {
38 	/* Mark this context has been used on the new CPU */
39 	cpumask_set_cpu(smp_processor_id(), mm_cpumask(next));
40 
41 	/* 32-bit keeps track of the current PGDIR in the thread struct */
42 #ifdef CONFIG_PPC32
43 	tsk->thread.pgdir = next->pgd;
44 #endif /* CONFIG_PPC32 */
45 
46 	/* 64-bit Book3E keeps track of current PGD in the PACA */
47 #ifdef CONFIG_PPC_BOOK3E_64
48 	get_paca()->pgd = next->pgd;
49 #endif
50 	/* Nothing else to do if we aren't actually switching */
51 	if (prev == next)
52 		return;
53 
54 	/* We must stop all altivec streams before changing the HW
55 	 * context
56 	 */
57 #ifdef CONFIG_ALTIVEC
58 	if (cpu_has_feature(CPU_FTR_ALTIVEC))
59 		asm volatile ("dssall");
60 #endif /* CONFIG_ALTIVEC */
61 
62 	/* The actual HW switching method differs between the various
63 	 * sub architectures.
64 	 */
65 #ifdef CONFIG_PPC_STD_MMU_64
66 	if (cpu_has_feature(CPU_FTR_SLB))
67 		switch_slb(tsk, next);
68 	else
69 		switch_stab(tsk, next);
70 #else
71 	/* Out of line for now */
72 	switch_mmu_context(prev, next);
73 #endif
74 
75 }
76 
77 #define deactivate_mm(tsk,mm)	do { } while (0)
78 
79 /*
80  * After we have set current->mm to a new value, this activates
81  * the context for the new mm so we see the new mappings.
82  */
83 static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
84 {
85 	unsigned long flags;
86 
87 	local_irq_save(flags);
88 	switch_mm(prev, next, current);
89 	local_irq_restore(flags);
90 }
91 
92 /* We don't currently use enter_lazy_tlb() for anything */
93 static inline void enter_lazy_tlb(struct mm_struct *mm,
94 				  struct task_struct *tsk)
95 {
96 	/* 64-bit Book3E keeps track of current PGD in the PACA */
97 #ifdef CONFIG_PPC_BOOK3E_64
98 	get_paca()->pgd = NULL;
99 #endif
100 }
101 
102 #endif /* __KERNEL__ */
103 #endif /* __ASM_POWERPC_MMU_CONTEXT_H */
104