xref: /linux/arch/powerpc/include/asm/mmu_context.h (revision 3932b9ca55b0be314a36d3e84faff3e823c081f5)
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_slb(struct task_struct *tsk, struct mm_struct *mm);
22 extern void set_context(unsigned long id, pgd_t *pgd);
23 
24 #ifdef CONFIG_PPC_BOOK3S_64
25 extern int __init_new_context(void);
26 extern void __destroy_context(int context_id);
27 static inline void mmu_context_init(void) { }
28 #else
29 extern unsigned long __init_new_context(void);
30 extern void __destroy_context(unsigned long context_id);
31 extern void mmu_context_init(void);
32 #endif
33 
34 extern void switch_cop(struct mm_struct *next);
35 extern int use_cop(unsigned long acop, struct mm_struct *mm);
36 extern void drop_cop(unsigned long acop, struct mm_struct *mm);
37 
38 /*
39  * switch_mm is the entry point called from the architecture independent
40  * code in kernel/sched/core.c
41  */
42 static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
43 			     struct task_struct *tsk)
44 {
45 	/* Mark this context has been used on the new CPU */
46 	cpumask_set_cpu(smp_processor_id(), mm_cpumask(next));
47 
48 	/* 32-bit keeps track of the current PGDIR in the thread struct */
49 #ifdef CONFIG_PPC32
50 	tsk->thread.pgdir = next->pgd;
51 #endif /* CONFIG_PPC32 */
52 
53 	/* 64-bit Book3E keeps track of current PGD in the PACA */
54 #ifdef CONFIG_PPC_BOOK3E_64
55 	get_paca()->pgd = next->pgd;
56 #endif
57 	/* Nothing else to do if we aren't actually switching */
58 	if (prev == next)
59 		return;
60 
61 #ifdef CONFIG_PPC_ICSWX
62 	/* Switch coprocessor context only if prev or next uses a coprocessor */
63 	if (prev->context.acop || next->context.acop)
64 		switch_cop(next);
65 #endif /* CONFIG_PPC_ICSWX */
66 
67 	/* We must stop all altivec streams before changing the HW
68 	 * context
69 	 */
70 #ifdef CONFIG_ALTIVEC
71 	if (cpu_has_feature(CPU_FTR_ALTIVEC))
72 		asm volatile ("dssall");
73 #endif /* CONFIG_ALTIVEC */
74 
75 	/* The actual HW switching method differs between the various
76 	 * sub architectures.
77 	 */
78 #ifdef CONFIG_PPC_STD_MMU_64
79 	switch_slb(tsk, next);
80 #else
81 	/* Out of line for now */
82 	switch_mmu_context(prev, next);
83 #endif
84 
85 }
86 
87 #define deactivate_mm(tsk,mm)	do { } while (0)
88 
89 /*
90  * After we have set current->mm to a new value, this activates
91  * the context for the new mm so we see the new mappings.
92  */
93 static inline void activate_mm(struct mm_struct *prev, struct mm_struct *next)
94 {
95 	unsigned long flags;
96 
97 	local_irq_save(flags);
98 	switch_mm(prev, next, current);
99 	local_irq_restore(flags);
100 }
101 
102 /* We don't currently use enter_lazy_tlb() for anything */
103 static inline void enter_lazy_tlb(struct mm_struct *mm,
104 				  struct task_struct *tsk)
105 {
106 	/* 64-bit Book3E keeps track of current PGD in the PACA */
107 #ifdef CONFIG_PPC_BOOK3E_64
108 	get_paca()->pgd = NULL;
109 #endif
110 }
111 
112 #endif /* __KERNEL__ */
113 #endif /* __ASM_POWERPC_MMU_CONTEXT_H */
114