1#ifndef _ASM_M32R_MMU_CONTEXT_H
  2#define _ASM_M32R_MMU_CONTEXT_H
  3#ifdef __KERNEL__
  4
  5#include <asm/m32r.h>
  6
  7#define MMU_CONTEXT_ASID_MASK      (0x000000FF)
  8#define MMU_CONTEXT_VERSION_MASK   (0xFFFFFF00)
  9#define MMU_CONTEXT_FIRST_VERSION  (0x00000100)
 10#define NO_CONTEXT                 (0x00000000)
 11
 12#ifndef __ASSEMBLY__
 13
 14#include <linux/atomic.h>
 15#include <asm/pgalloc.h>
 16#include <asm/mmu.h>
 17#include <asm/tlbflush.h>
 18#include <asm-generic/mm_hooks.h>
 19
 20/*
 21 * Cache of MMU context last used.
 22 */
 23#ifndef CONFIG_SMP
 24extern unsigned long mmu_context_cache_dat;
 25#define mmu_context_cache	mmu_context_cache_dat
 26#define mm_context(mm)		mm->context
 27#else /* not CONFIG_SMP */
 28extern unsigned long mmu_context_cache_dat[];
 29#define mmu_context_cache	mmu_context_cache_dat[smp_processor_id()]
 30#define mm_context(mm)		mm->context[smp_processor_id()]
 31#endif /* not CONFIG_SMP */
 32
 33#define set_tlb_tag(entry, tag)		(*entry = (tag & PAGE_MASK)|get_asid())
 34#define set_tlb_data(entry, data)	(*entry = (data | _PAGE_PRESENT))
 35
 36#ifdef CONFIG_MMU
 37#define enter_lazy_tlb(mm, tsk)	do { } while (0)
 38
 39static inline void get_new_mmu_context(struct mm_struct *mm)
 40{
 41	unsigned long mc = ++mmu_context_cache;
 42
 43	if (!(mc & MMU_CONTEXT_ASID_MASK)) {
 44		/* We exhaust ASID of this version.
 45		   Flush all TLB and start new cycle. */
 46		local_flush_tlb_all();
 47		/* Fix version if needed.
 48		   Note that we avoid version #0 to distingush NO_CONTEXT. */
 49		if (!mc)
 50			mmu_context_cache = mc = MMU_CONTEXT_FIRST_VERSION;
 51	}
 52	mm_context(mm) = mc;
 53}
 54
 55/*
 56 * Get MMU context if needed.
 57 */
 58static inline void get_mmu_context(struct mm_struct *mm)
 59{
 60	if (mm) {
 61		unsigned long mc = mmu_context_cache;
 62
 63		/* Check if we have old version of context.
 64		   If it's old, we need to get new context with new version. */
 65		if ((mm_context(mm) ^ mc) & MMU_CONTEXT_VERSION_MASK)
 66			get_new_mmu_context(mm);
 67	}
 68}
 69
 70/*
 71 * Initialize the context related info for a new mm_struct
 72 * instance.
 73 */
 74static inline int init_new_context(struct task_struct *tsk,
 75	struct mm_struct *mm)
 76{
 77#ifndef CONFIG_SMP
 78	mm->context = NO_CONTEXT;
 79#else /* CONFIG_SMP */
 80	int num_cpus = num_online_cpus();
 81	int i;
 82
 83	for (i = 0 ; i < num_cpus ; i++)
 84		mm->context[i] = NO_CONTEXT;
 85#endif /* CONFIG_SMP */
 86
 87	return 0;
 88}
 89
 90/*
 91 * Destroy context related info for an mm_struct that is about
 92 * to be put to rest.
 93 */
 94#define destroy_context(mm)	do { } while (0)
 95
 96static inline void set_asid(unsigned long asid)
 97{
 98	*(volatile unsigned long *)MASID = (asid & MMU_CONTEXT_ASID_MASK);
 99}
100
101static inline unsigned long get_asid(void)
102{
103	unsigned long asid;
104
105	asid = *(volatile long *)MASID;
106	asid &= MMU_CONTEXT_ASID_MASK;
107
108	return asid;
109}
110
111/*
112 * After we have set current->mm to a new value, this activates
113 * the context for the new mm so we see the new mappings.
114 */
115static inline void activate_context(struct mm_struct *mm)
116{
117	get_mmu_context(mm);
118	set_asid(mm_context(mm) & MMU_CONTEXT_ASID_MASK);
119}
120
121static inline void switch_mm(struct mm_struct *prev,
122	struct mm_struct *next, struct task_struct *tsk)
123{
124#ifdef CONFIG_SMP
125	int cpu = smp_processor_id();
126#endif	/* CONFIG_SMP */
127
128	if (prev != next) {
129#ifdef CONFIG_SMP
130		cpumask_set_cpu(cpu, mm_cpumask(next));
131#endif /* CONFIG_SMP */
132		/* Set MPTB = next->pgd */
133		*(volatile unsigned long *)MPTB = (unsigned long)next->pgd;
134		activate_context(next);
135	}
136#ifdef CONFIG_SMP
137	else
138		if (!cpumask_test_and_set_cpu(cpu, mm_cpumask(next)))
139			activate_context(next);
140#endif /* CONFIG_SMP */
141}
142
143#define deactivate_mm(tsk, mm)	do { } while (0)
144
145#define activate_mm(prev, next)	\
146	switch_mm((prev), (next), NULL)
147
148#else /* not CONFIG_MMU */
149#define get_mmu_context(mm)             do { } while (0)
150#define init_new_context(tsk,mm)        (0)
151#define destroy_context(mm)             do { } while (0)
152#define set_asid(asid)                  do { } while (0)
153#define get_asid()                      (0)
154#define activate_context(mm)            do { } while (0)
155#define switch_mm(prev,next,tsk)        do { } while (0)
156#define deactivate_mm(mm,tsk)           do { } while (0)
157#define activate_mm(prev,next)          do { } while (0)
158#define enter_lazy_tlb(mm,tsk)          do { } while (0)
159#endif /* not CONFIG_MMU */
160
161#endif /* not __ASSEMBLY__ */
162
163#endif /* __KERNEL__ */
164#endif /* _ASM_M32R_MMU_CONTEXT_H */