/arch/powerpc/include/asm/mmu_context.h

  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 */
 17extern int init_new_context(struct task_struct *tsk, struct mm_struct *mm);
 18extern void destroy_context(struct mm_struct *mm);
 19
 20extern void switch_mmu_context(struct mm_struct *prev, struct mm_struct *next);
 21extern void switch_stab(struct task_struct *tsk, struct mm_struct *mm);
 22extern void switch_slb(struct task_struct *tsk, struct mm_struct *mm);
 23extern void set_context(unsigned long id, pgd_t *pgd);
 24
 25#ifdef CONFIG_PPC_BOOK3S_64
 26extern int __init_new_context(void);
 27extern void __destroy_context(int context_id);
 28static inline void mmu_context_init(void) { }
 29#else
 30extern unsigned long __init_new_context(void);
 31extern void __destroy_context(unsigned long context_id);
 32extern 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 */
 39static 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 */
 87static 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 */
 97static 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 */