xref: /linux/arch/powerpc/include/asm/mmu_context.h (revision c4ee0af3fa0dc65f690fc908f02b8355f9576ea0)
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 extern void switch_cop(struct mm_struct *next);
36 extern int use_cop(unsigned long acop, struct mm_struct *mm);
37 extern void drop_cop(unsigned long acop, struct mm_struct *mm);
38 
39 /*
40  * switch_mm is the entry point called from the architecture independent
41  * code in kernel/sched/core.c
42  */
43 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
44 			     struct task_struct *tsk)
45 {
46 	/* Mark this context has been used on the new CPU */
47 	cpumask_set_cpu(smp_processor_id(), mm_cpumask(next));
48 
49 	/* 32-bit keeps track of the current PGDIR in the thread struct */
50 #ifdef CONFIG_PPC32
51 	tsk->thread.pgdir = next->pgd;
52 #endif /* CONFIG_PPC32 */
53 
54 	/* 64-bit Book3E keeps track of current PGD in the PACA */
55 #ifdef CONFIG_PPC_BOOK3E_64
56 	get_paca()->pgd = next->pgd;
57 #endif
58 	/* Nothing else to do if we aren't actually switching */
59 	if (prev == next)
60 		return;
61 
62 #ifdef CONFIG_PPC_ICSWX
63 	/* Switch coprocessor context only if prev or next uses a coprocessor */
64 	if (prev->context.acop || next->context.acop)
65 		switch_cop(next);
66 #endif /* CONFIG_PPC_ICSWX */
67 
68 	/* We must stop all altivec streams before changing the HW
69 	 * context
70 	 */
71 #ifdef CONFIG_ALTIVEC
72 	if (cpu_has_feature(CPU_FTR_ALTIVEC))
73 		asm volatile ("dssall");
74 #endif /* CONFIG_ALTIVEC */
75 
76 	/* The actual HW switching method differs between the various
77 	 * sub architectures.
78 	 */
79 #ifdef CONFIG_PPC_STD_MMU_64
80 	if (mmu_has_feature(MMU_FTR_SLB))
81 		switch_slb(tsk, next);
82 	else
83 		switch_stab(tsk, next);
84 #else
85 	/* Out of line for now */
86 	switch_mmu_context(prev, next);
87 #endif
88 
89 }
90 
91 #define deactivate_mm(tsk,mm)	do { } while (0)
92 
93 /*
94  * After we have set current->mm to a new value, this activates
95  * the context for the new mm so we see the new mappings.
96  */
97 static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
98 {
99 	unsigned long flags;
100 
101 	local_irq_save(flags);
102 	switch_mm(prev, next, current);
103 	local_irq_restore(flags);
104 }
105 
106 /* We don't currently use enter_lazy_tlb() for anything */
107 static inline void enter_lazy_tlb(struct mm_struct *mm,
108 				  struct task_struct *tsk)
109 {
110 	/* 64-bit Book3E keeps track of current PGD in the PACA */
111 #ifdef CONFIG_PPC_BOOK3E_64
112 	get_paca()->pgd = NULL;
113 #endif
114 }
115 
116 #endif /* __KERNEL__ */
117 #endif /* __ASM_POWERPC_MMU_CONTEXT_H */
118