diff options
author | Ingo Molnar <mingo@elte.hu> | 2008-07-18 13:31:12 -0400 |
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committer | Ingo Molnar <mingo@elte.hu> | 2008-07-18 13:31:12 -0400 |
commit | 3e370b29d35fb01bfb92c2814d6f79bf6a2cb970 (patch) | |
tree | 3b8fb467d60bfe6a34686f4abdc3a60050ba40a4 /include/asm-ppc/mmu_context.h | |
parent | 88d1dce3a74367291f65a757fbdcaf17f042f30c (diff) | |
parent | 5b664cb235e97afbf34db9c4d77f08ebd725335e (diff) |
Merge branch 'linus' into x86/pci-ioapic-boot-irq-quirks
Conflicts:
drivers/pci/quirks.c
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'include/asm-ppc/mmu_context.h')
-rw-r--r-- | include/asm-ppc/mmu_context.h | 198 |
1 files changed, 0 insertions, 198 deletions
diff --git a/include/asm-ppc/mmu_context.h b/include/asm-ppc/mmu_context.h deleted file mode 100644 index 9f097e25b169..000000000000 --- a/include/asm-ppc/mmu_context.h +++ /dev/null | |||
@@ -1,198 +0,0 @@ | |||
1 | #ifdef __KERNEL__ | ||
2 | #ifndef __PPC_MMU_CONTEXT_H | ||
3 | #define __PPC_MMU_CONTEXT_H | ||
4 | |||
5 | #include <linux/bitops.h> | ||
6 | |||
7 | #include <asm/atomic.h> | ||
8 | #include <asm/mmu.h> | ||
9 | #include <asm/cputable.h> | ||
10 | #include <asm-generic/mm_hooks.h> | ||
11 | |||
12 | /* | ||
13 | * On 32-bit PowerPC 6xx/7xx/7xxx CPUs, we use a set of 16 VSIDs | ||
14 | * (virtual segment identifiers) for each context. Although the | ||
15 | * hardware supports 24-bit VSIDs, and thus >1 million contexts, | ||
16 | * we only use 32,768 of them. That is ample, since there can be | ||
17 | * at most around 30,000 tasks in the system anyway, and it means | ||
18 | * that we can use a bitmap to indicate which contexts are in use. | ||
19 | * Using a bitmap means that we entirely avoid all of the problems | ||
20 | * that we used to have when the context number overflowed, | ||
21 | * particularly on SMP systems. | ||
22 | * -- paulus. | ||
23 | */ | ||
24 | |||
25 | /* | ||
26 | * This function defines the mapping from contexts to VSIDs (virtual | ||
27 | * segment IDs). We use a skew on both the context and the high 4 bits | ||
28 | * of the 32-bit virtual address (the "effective segment ID") in order | ||
29 | * to spread out the entries in the MMU hash table. Note, if this | ||
30 | * function is changed then arch/ppc/mm/hashtable.S will have to be | ||
31 | * changed to correspond. | ||
32 | */ | ||
33 | #define CTX_TO_VSID(ctx, va) (((ctx) * (897 * 16) + ((va) >> 28) * 0x111) \ | ||
34 | & 0xffffff) | ||
35 | |||
36 | /* | ||
37 | The MPC8xx has only 16 contexts. We rotate through them on each | ||
38 | task switch. A better way would be to keep track of tasks that | ||
39 | own contexts, and implement an LRU usage. That way very active | ||
40 | tasks don't always have to pay the TLB reload overhead. The | ||
41 | kernel pages are mapped shared, so the kernel can run on behalf | ||
42 | of any task that makes a kernel entry. Shared does not mean they | ||
43 | are not protected, just that the ASID comparison is not performed. | ||
44 | -- Dan | ||
45 | |||
46 | The IBM4xx has 256 contexts, so we can just rotate through these | ||
47 | as a way of "switching" contexts. If the TID of the TLB is zero, | ||
48 | the PID/TID comparison is disabled, so we can use a TID of zero | ||
49 | to represent all kernel pages as shared among all contexts. | ||
50 | -- Dan | ||
51 | */ | ||
52 | |||
53 | static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk) | ||
54 | { | ||
55 | } | ||
56 | |||
57 | #ifdef CONFIG_8xx | ||
58 | #define NO_CONTEXT 16 | ||
59 | #define LAST_CONTEXT 15 | ||
60 | #define FIRST_CONTEXT 0 | ||
61 | |||
62 | #elif defined(CONFIG_4xx) | ||
63 | #define NO_CONTEXT 256 | ||
64 | #define LAST_CONTEXT 255 | ||
65 | #define FIRST_CONTEXT 1 | ||
66 | |||
67 | #else | ||
68 | |||
69 | /* PPC 6xx, 7xx CPUs */ | ||
70 | #define NO_CONTEXT ((unsigned long) -1) | ||
71 | #define LAST_CONTEXT 32767 | ||
72 | #define FIRST_CONTEXT 1 | ||
73 | #endif | ||
74 | |||
75 | /* | ||
76 | * Set the current MMU context. | ||
77 | * On 32-bit PowerPCs (other than the 8xx embedded chips), this is done by | ||
78 | * loading up the segment registers for the user part of the address space. | ||
79 | * | ||
80 | * Since the PGD is immediately available, it is much faster to simply | ||
81 | * pass this along as a second parameter, which is required for 8xx and | ||
82 | * can be used for debugging on all processors (if you happen to have | ||
83 | * an Abatron). | ||
84 | */ | ||
85 | extern void set_context(unsigned long contextid, pgd_t *pgd); | ||
86 | |||
87 | /* | ||
88 | * Bitmap of contexts in use. | ||
89 | * The size of this bitmap is LAST_CONTEXT + 1 bits. | ||
90 | */ | ||
91 | extern unsigned long context_map[]; | ||
92 | |||
93 | /* | ||
94 | * This caches the next context number that we expect to be free. | ||
95 | * Its use is an optimization only, we can't rely on this context | ||
96 | * number to be free, but it usually will be. | ||
97 | */ | ||
98 | extern unsigned long next_mmu_context; | ||
99 | |||
100 | /* | ||
101 | * If we don't have sufficient contexts to give one to every task | ||
102 | * that could be in the system, we need to be able to steal contexts. | ||
103 | * These variables support that. | ||
104 | */ | ||
105 | #if LAST_CONTEXT < 30000 | ||
106 | #define FEW_CONTEXTS 1 | ||
107 | extern atomic_t nr_free_contexts; | ||
108 | extern struct mm_struct *context_mm[LAST_CONTEXT+1]; | ||
109 | extern void steal_context(void); | ||
110 | #endif | ||
111 | |||
112 | /* | ||
113 | * Get a new mmu context for the address space described by `mm'. | ||
114 | */ | ||
115 | static inline void get_mmu_context(struct mm_struct *mm) | ||
116 | { | ||
117 | unsigned long ctx; | ||
118 | |||
119 | if (mm->context.id != NO_CONTEXT) | ||
120 | return; | ||
121 | #ifdef FEW_CONTEXTS | ||
122 | while (atomic_dec_if_positive(&nr_free_contexts) < 0) | ||
123 | steal_context(); | ||
124 | #endif | ||
125 | ctx = next_mmu_context; | ||
126 | while (test_and_set_bit(ctx, context_map)) { | ||
127 | ctx = find_next_zero_bit(context_map, LAST_CONTEXT+1, ctx); | ||
128 | if (ctx > LAST_CONTEXT) | ||
129 | ctx = 0; | ||
130 | } | ||
131 | next_mmu_context = (ctx + 1) & LAST_CONTEXT; | ||
132 | mm->context.id = ctx; | ||
133 | #ifdef FEW_CONTEXTS | ||
134 | context_mm[ctx] = mm; | ||
135 | #endif | ||
136 | } | ||
137 | |||
138 | /* | ||
139 | * Set up the context for a new address space. | ||
140 | */ | ||
141 | static inline int init_new_context(struct task_struct *t, struct mm_struct *mm) | ||
142 | { | ||
143 | mm->context.id = NO_CONTEXT; | ||
144 | mm->context.vdso_base = 0; | ||
145 | return 0; | ||
146 | } | ||
147 | |||
148 | /* | ||
149 | * We're finished using the context for an address space. | ||
150 | */ | ||
151 | static inline void destroy_context(struct mm_struct *mm) | ||
152 | { | ||
153 | preempt_disable(); | ||
154 | if (mm->context.id != NO_CONTEXT) { | ||
155 | clear_bit(mm->context.id, context_map); | ||
156 | mm->context.id = NO_CONTEXT; | ||
157 | #ifdef FEW_CONTEXTS | ||
158 | atomic_inc(&nr_free_contexts); | ||
159 | #endif | ||
160 | } | ||
161 | preempt_enable(); | ||
162 | } | ||
163 | |||
164 | static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next, | ||
165 | struct task_struct *tsk) | ||
166 | { | ||
167 | #ifdef CONFIG_ALTIVEC | ||
168 | if (cpu_has_feature(CPU_FTR_ALTIVEC)) | ||
169 | asm volatile ("dssall;\n" | ||
170 | #ifndef CONFIG_POWER4 | ||
171 | "sync;\n" /* G4 needs a sync here, G5 apparently not */ | ||
172 | #endif | ||
173 | : : ); | ||
174 | #endif /* CONFIG_ALTIVEC */ | ||
175 | |||
176 | tsk->thread.pgdir = next->pgd; | ||
177 | |||
178 | /* No need to flush userspace segments if the mm doesnt change */ | ||
179 | if (prev == next) | ||
180 | return; | ||
181 | |||
182 | /* Setup new userspace context */ | ||
183 | get_mmu_context(next); | ||
184 | set_context(next->context.id, next->pgd); | ||
185 | } | ||
186 | |||
187 | #define deactivate_mm(tsk,mm) do { } while (0) | ||
188 | |||
189 | /* | ||
190 | * After we have set current->mm to a new value, this activates | ||
191 | * the context for the new mm so we see the new mappings. | ||
192 | */ | ||
193 | #define activate_mm(active_mm, mm) switch_mm(active_mm, mm, current) | ||
194 | |||
195 | extern void mmu_context_init(void); | ||
196 | |||
197 | #endif /* __PPC_MMU_CONTEXT_H */ | ||
198 | #endif /* __KERNEL__ */ | ||