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/spitfire.h>
10 #include <asm-generic/mm_hooks.h>
11
enter_lazy_tlb(struct mm_struct * mm,struct task_struct * tsk)12 static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
13 {
14 }
15
16 extern spinlock_t ctx_alloc_lock;
17 extern unsigned long tlb_context_cache;
18 extern unsigned long mmu_context_bmap[];
19
20 DECLARE_PER_CPU(struct mm_struct *, per_cpu_secondary_mm);
21 void get_new_mmu_context(struct mm_struct *mm);
22 int init_new_context(struct task_struct *tsk, struct mm_struct *mm);
23 void destroy_context(struct mm_struct *mm);
24
25 void __tsb_context_switch(unsigned long pgd_pa,
26 struct tsb_config *tsb_base,
27 struct tsb_config *tsb_huge,
28 unsigned long tsb_descr_pa,
29 unsigned long secondary_ctx);
30
tsb_context_switch_ctx(struct mm_struct * mm,unsigned long ctx)31 static inline void tsb_context_switch_ctx(struct mm_struct *mm,
32 unsigned long ctx)
33 {
34 __tsb_context_switch(__pa(mm->pgd),
35 &mm->context.tsb_block[0],
36 #if defined(CONFIG_HUGETLB_PAGE) || defined(CONFIG_TRANSPARENT_HUGEPAGE)
37 (mm->context.tsb_block[1].tsb ?
38 &mm->context.tsb_block[1] :
39 NULL)
40 #else
41 NULL
42 #endif
43 , __pa(&mm->context.tsb_descr[0]),
44 ctx);
45 }
46
47 #define tsb_context_switch(X) tsb_context_switch_ctx(X, 0)
48
49 void tsb_grow(struct mm_struct *mm,
50 unsigned long tsb_index,
51 unsigned long mm_rss);
52 #ifdef CONFIG_SMP
53 void smp_tsb_sync(struct mm_struct *mm);
54 #else
55 #define smp_tsb_sync(__mm) do { } while (0)
56 #endif
57
58 /* Set MMU context in the actual hardware. */
59 #define load_secondary_context(__mm) \
60 __asm__ __volatile__( \
61 "\n661: stxa %0, [%1] %2\n" \
62 " .section .sun4v_1insn_patch, \"ax\"\n" \
63 " .word 661b\n" \
64 " stxa %0, [%1] %3\n" \
65 " .previous\n" \
66 " flush %%g6\n" \
67 : /* No outputs */ \
68 : "r" (CTX_HWBITS((__mm)->context)), \
69 "r" (SECONDARY_CONTEXT), "i" (ASI_DMMU), "i" (ASI_MMU))
70
71 void __flush_tlb_mm(unsigned long, unsigned long);
72
73 /* Switch the current MM context. */
switch_mm(struct mm_struct * old_mm,struct mm_struct * mm,struct task_struct * tsk)74 static inline void switch_mm(struct mm_struct *old_mm, struct mm_struct *mm, struct task_struct *tsk)
75 {
76 unsigned long ctx_valid, flags;
77 int cpu = smp_processor_id();
78
79 per_cpu(per_cpu_secondary_mm, cpu) = mm;
80 if (unlikely(mm == &init_mm))
81 return;
82
83 spin_lock_irqsave(&mm->context.lock, flags);
84 ctx_valid = CTX_VALID(mm->context);
85 if (!ctx_valid)
86 get_new_mmu_context(mm);
87
88 /* We have to be extremely careful here or else we will miss
89 * a TSB grow if we switch back and forth between a kernel
90 * thread and an address space which has it's TSB size increased
91 * on another processor.
92 *
93 * It is possible to play some games in order to optimize the
94 * switch, but the safest thing to do is to unconditionally
95 * perform the secondary context load and the TSB context switch.
96 *
97 * For reference the bad case is, for address space "A":
98 *
99 * CPU 0 CPU 1
100 * run address space A
101 * set cpu0's bits in cpu_vm_mask
102 * switch to kernel thread, borrow
103 * address space A via entry_lazy_tlb
104 * run address space A
105 * set cpu1's bit in cpu_vm_mask
106 * flush_tlb_pending()
107 * reset cpu_vm_mask to just cpu1
108 * TSB grow
109 * run address space A
110 * context was valid, so skip
111 * TSB context switch
112 *
113 * At that point cpu0 continues to use a stale TSB, the one from
114 * before the TSB grow performed on cpu1. cpu1 did not cross-call
115 * cpu0 to update it's TSB because at that point the cpu_vm_mask
116 * only had cpu1 set in it.
117 */
118 tsb_context_switch_ctx(mm, CTX_HWBITS(mm->context));
119
120 /* Any time a processor runs a context on an address space
121 * for the first time, we must flush that context out of the
122 * local TLB.
123 */
124 if (!ctx_valid || !cpumask_test_cpu(cpu, mm_cpumask(mm))) {
125 cpumask_set_cpu(cpu, mm_cpumask(mm));
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 #define activate_mm(active_mm, mm) switch_mm(active_mm, mm, NULL)
134 #endif /* !(__ASSEMBLY__) */
135
136 #endif /* !(__SPARC64_MMU_CONTEXT_H) */
137