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 extern int __init_new_context(void);
27 extern void __destroy_context(int context_id);
28 static inline void mmu_context_init(void) { }
29 #else
30 extern unsigned long __init_new_context(void);
31 extern void __destroy_context(unsigned long context_id);
32 extern void mmu_context_init(void);
33 #endif
34 
35 /*
36  * switch_mm is the entry point called from the architecture independent
37  * code in kernel/sched.c
38  */
39 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
40 			     struct task_struct *tsk)
41 {
42 	/* Mark this context has been used on the new CPU */
43 	cpumask_set_cpu(smp_processor_id(), mm_cpumask(next));
44 
45 	/* 32-bit keeps track of the current PGDIR in the thread struct */
46 #ifdef CONFIG_PPC32
47 	tsk->thread.pgdir = next->pgd;
48 #endif /* CONFIG_PPC32 */
49 
50 	/* 64-bit Book3E keeps track of current PGD in the PACA */
51 #ifdef CONFIG_PPC_BOOK3E_64
52 	get_paca()->pgd = next->pgd;
53 #endif
54 	/* Nothing else to do if we aren't actually switching */
55 	if (prev == next)
56 		return;
57 
58 	/* We must stop all altivec streams before changing the HW
59 	 * context
60 	 */
61 #ifdef CONFIG_ALTIVEC
62 	if (cpu_has_feature(CPU_FTR_ALTIVEC))
63 		asm volatile ("dssall");
64 #endif /* CONFIG_ALTIVEC */
65 
66 	/* The actual HW switching method differs between the various
67 	 * sub architectures.
68 	 */
69 #ifdef CONFIG_PPC_STD_MMU_64
70 	if (cpu_has_feature(CPU_FTR_SLB))
71 		switch_slb(tsk, next);
72 	else
73 		switch_stab(tsk, next);
74 #else
75 	/* Out of line for now */
76 	switch_mmu_context(prev, next);
77 #endif
78 
79 }
80 
81 #define deactivate_mm(tsk,mm)	do { } while (0)
82 
83 /*
84  * After we have set current->mm to a new value, this activates
85  * the context for the new mm so we see the new mappings.
86  */
87 static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
88 {
89 	unsigned long flags;
90 
91 	local_irq_save(flags);
92 	switch_mm(prev, next, current);
93 	local_irq_restore(flags);
94 }
95 
96 /* We don't currently use enter_lazy_tlb() for anything */
97 static inline void enter_lazy_tlb(struct mm_struct *mm,
98 				  struct task_struct *tsk)
99 {
100 	/* 64-bit Book3E keeps track of current PGD in the PACA */
101 #ifdef CONFIG_PPC_BOOK3E_64
102 	get_paca()->pgd = NULL;
103 #endif
104 }
105 
106 #endif /* __KERNEL__ */
107 #endif /* __ASM_POWERPC_MMU_CONTEXT_H */
108