Gitiles
Code Review Sign In
gerrit-public.fairphone.software / kernel / msm-4.9 / c91ebe496120e05301465fff31094bfecf798e9f / . / arch / sparc / include / asm / mmu_context_64.h
blob: 5693ab4826067056873803b6324b437e6275453f [file] [log] [blame]
Sam Ravnborgf5e706a2008-07-17 21:55:51 -0700[diff] [blame]1#ifndef __SPARC64_MMU_CONTEXT_H
2#define __SPARC64_MMU_CONTEXT_H
3
4/* Derived heavily from Linus's Alpha/AXP ASN code... */
5
6#ifndef __ASSEMBLY__
7
8#include <linux/spinlock.h>
9#include <asm/system.h>
10#include <asm/spitfire.h>
11#include <asm-generic/mm_hooks.h>
12
13static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
14{
15}
16
17extern spinlock_t ctx_alloc_lock;
18extern unsigned long tlb_context_cache;
19extern unsigned long mmu_context_bmap[];
20
21extern void get_new_mmu_context(struct mm_struct *mm);
22#ifdef CONFIG_SMP
23extern void smp_new_mmu_context_version(void);
24#else
25#define smp_new_mmu_context_version() do { } while (0)
26#endif
27
28extern int init_new_context(struct task_struct *tsk, struct mm_struct *mm);
29extern void destroy_context(struct mm_struct *mm);
30
31extern void __tsb_context_switch(unsigned long pgd_pa,
32 struct tsb_config *tsb_base,
33 struct tsb_config *tsb_huge,
34 unsigned long tsb_descr_pa);
35
36static inline void tsb_context_switch(struct mm_struct *mm)
37{
38 __tsb_context_switch(__pa(mm->pgd),
39 &mm->context.tsb_block[0],
40#ifdef CONFIG_HUGETLB_PAGE
41 (mm->context.tsb_block[1].tsb ?
42 &mm->context.tsb_block[1] :
43 NULL)
44#else
45 NULL
46#endif
47 , __pa(&mm->context.tsb_descr[0]));
48}
49
50extern void tsb_grow(struct mm_struct *mm, unsigned long tsb_index, unsigned long mm_rss);
51#ifdef CONFIG_SMP
52extern void smp_tsb_sync(struct mm_struct *mm);
53#else
54#define smp_tsb_sync(__mm) do { } while (0)
55#endif
56
57/* Set MMU context in the actual hardware. */
58#define load_secondary_context(__mm) \
59 __asm__ __volatile__( \
60 "\n661: stxa %0, [%1] %2\n" \
61 " .section .sun4v_1insn_patch, \"ax\"\n" \
62 " .word 661b\n" \
63 " stxa %0, [%1] %3\n" \
64 " .previous\n" \
65 " flush %%g6\n" \
66 : /* No outputs */ \
67 : "r" (CTX_HWBITS((__mm)->context)), \
68 "r" (SECONDARY_CONTEXT), "i" (ASI_DMMU), "i" (ASI_MMU))
69
70extern void __flush_tlb_mm(unsigned long, unsigned long);
71
72/* Switch the current MM context. Interrupts are disabled. */
73static inline void switch_mm(struct mm_struct *old_mm, struct mm_struct *mm, struct task_struct *tsk)
74{
75 unsigned long ctx_valid, flags;
76 int cpu;
77
78 if (unlikely(mm == &init_mm))
79 return;
80
81 spin_lock_irqsave(&mm->context.lock, flags);
82 ctx_valid = CTX_VALID(mm->context);
83 if (!ctx_valid)
84 get_new_mmu_context(mm);
85
86 /* We have to be extremely careful here or else we will miss
87 * a TSB grow if we switch back and forth between a kernel
88 * thread and an address space which has it's TSB size increased
89 * on another processor.
90 *
91 * It is possible to play some games in order to optimize the
92 * switch, but the safest thing to do is to unconditionally
93 * perform the secondary context load and the TSB context switch.
94 *
95 * For reference the bad case is, for address space "A":
96 *
97 * CPU 0 CPU 1
98 * run address space A
99 * set cpu0's bits in cpu_vm_mask
100 * switch to kernel thread, borrow
101 * address space A via entry_lazy_tlb
102 * run address space A
103 * set cpu1's bit in cpu_vm_mask
104 * flush_tlb_pending()
105 * reset cpu_vm_mask to just cpu1
106 * TSB grow
107 * run address space A
108 * context was valid, so skip
109 * TSB context switch
110 *
111 * At that point cpu0 continues to use a stale TSB, the one from
112 * before the TSB grow performed on cpu1. cpu1 did not cross-call
113 * cpu0 to update it's TSB because at that point the cpu_vm_mask
114 * only had cpu1 set in it.
115 */
116 load_secondary_context(mm);
117 tsb_context_switch(mm);
118
119 /* Any time a processor runs a context on an address space
120 * for the first time, we must flush that context out of the
121 * local TLB.
122 */
123 cpu = smp_processor_id();
124 if (!ctx_valid || !cpu_isset(cpu, mm->cpu_vm_mask)) {
125 cpu_set(cpu, mm->cpu_vm_mask);
126 __flush_tlb_mm(CTX_HWBITS(mm->context),
127 SECONDARY_CONTEXT);
128 }
129 spin_unlock_irqrestore(&mm->context.lock, flags);
130}
131
132#define deactivate_mm(tsk,mm) do { } while (0)
133
134/* Activate a new MM instance for the current task. */
135static inline void activate_mm(struct mm_struct *active_mm, struct mm_struct *mm)
136{
137 unsigned long flags;
138 int cpu;
139
140 spin_lock_irqsave(&mm->context.lock, flags);
141 if (!CTX_VALID(mm->context))
142 get_new_mmu_context(mm);
143 cpu = smp_processor_id();
144 if (!cpu_isset(cpu, mm->cpu_vm_mask))
145 cpu_set(cpu, mm->cpu_vm_mask);
146
147 load_secondary_context(mm);
148 __flush_tlb_mm(CTX_HWBITS(mm->context), SECONDARY_CONTEXT);
149 tsb_context_switch(mm);
150 spin_unlock_irqrestore(&mm->context.lock, flags);
151}
152
153#endif /* !(__ASSEMBLY__) */
154
155#endif /* !(__SPARC64_MMU_CONTEXT_H) */