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authorChen, Kenneth W <kenneth.w.chen@intel.com>2005-10-29 21:47:04 -0400
committerTony Luck <tony.luck@intel.com>2005-11-03 17:43:50 -0500
commit58cd90829918dabbd81a453de676d41fb7b628ad (patch)
tree7806f84a89f767f3a9e78d0e198054f24fae0aee
parentdcc17d1baef3721d1574e5b2f4f2d4607514bcff (diff)
[IA64] make mmu_context.h and tlb.c 80-column friendly
wrap_mmu_context(), delayed_tlb_flush(), get_mmu_context() all have an extra { } block which cause one extra indentation. get_mmu_context() is particularly bad with 5 indentations to the most inner "if". It finally gets on my nerve that I can't keep the code within 80 columns. Remove the extra { } block and while I'm at it, reformat all the comments to 80-column friendly. No functional change at all with this patch. Signed-off-by: Ken Chen <kenneth.w.chen@intel.com> Signed-off-by: Tony Luck <tony.luck@intel.com>
-rw-r--r--arch/ia64/mm/tlb.c33
-rw-r--r--include/asm-ia64/mmu_context.h80
2 files changed, 59 insertions, 54 deletions
diff --git a/arch/ia64/mm/tlb.c b/arch/ia64/mm/tlb.c
index 39628fca274..41105d45442 100644
--- a/arch/ia64/mm/tlb.c
+++ b/arch/ia64/mm/tlb.c
@@ -29,7 +29,7 @@
29 29
30static struct { 30static struct {
31 unsigned long mask; /* mask of supported purge page-sizes */ 31 unsigned long mask; /* mask of supported purge page-sizes */
32 unsigned long max_bits; /* log2() of largest supported purge page-size */ 32 unsigned long max_bits; /* log2 of largest supported purge page-size */
33} purge; 33} purge;
34 34
35struct ia64_ctx ia64_ctx = { 35struct ia64_ctx ia64_ctx = {
@@ -58,7 +58,7 @@ mmu_context_init (void)
58void 58void
59wrap_mmu_context (struct mm_struct *mm) 59wrap_mmu_context (struct mm_struct *mm)
60{ 60{
61 int i; 61 int i, cpu;
62 unsigned long flush_bit; 62 unsigned long flush_bit;
63 63
64 for (i=0; i <= ia64_ctx.max_ctx / BITS_PER_LONG; i++) { 64 for (i=0; i <= ia64_ctx.max_ctx / BITS_PER_LONG; i++) {
@@ -72,20 +72,21 @@ wrap_mmu_context (struct mm_struct *mm)
72 ia64_ctx.limit = find_next_bit(ia64_ctx.bitmap, 72 ia64_ctx.limit = find_next_bit(ia64_ctx.bitmap,
73 ia64_ctx.max_ctx, ia64_ctx.next); 73 ia64_ctx.max_ctx, ia64_ctx.next);
74 74
75 /* can't call flush_tlb_all() here because of race condition with O(1) scheduler [EF] */ 75 /*
76 { 76 * can't call flush_tlb_all() here because of race condition
77 int cpu = get_cpu(); /* prevent preemption/migration */ 77 * with O(1) scheduler [EF]
78 for_each_online_cpu(i) { 78 */
79 if (i != cpu) 79 cpu = get_cpu(); /* prevent preemption/migration */
80 per_cpu(ia64_need_tlb_flush, i) = 1; 80 for_each_online_cpu(i)
81 } 81 if (i != cpu)
82 put_cpu(); 82 per_cpu(ia64_need_tlb_flush, i) = 1;
83 } 83 put_cpu();
84 local_flush_tlb_all(); 84 local_flush_tlb_all();
85} 85}
86 86
87void 87void
88ia64_global_tlb_purge (struct mm_struct *mm, unsigned long start, unsigned long end, unsigned long nbits) 88ia64_global_tlb_purge (struct mm_struct *mm, unsigned long start,
89 unsigned long end, unsigned long nbits)
89{ 90{
90 static DEFINE_SPINLOCK(ptcg_lock); 91 static DEFINE_SPINLOCK(ptcg_lock);
91 92
@@ -133,7 +134,8 @@ local_flush_tlb_all (void)
133} 134}
134 135
135void 136void
136flush_tlb_range (struct vm_area_struct *vma, unsigned long start, unsigned long end) 137flush_tlb_range (struct vm_area_struct *vma, unsigned long start,
138 unsigned long end)
137{ 139{
138 struct mm_struct *mm = vma->vm_mm; 140 struct mm_struct *mm = vma->vm_mm;
139 unsigned long size = end - start; 141 unsigned long size = end - start;
@@ -147,7 +149,8 @@ flush_tlb_range (struct vm_area_struct *vma, unsigned long start, unsigned long
147#endif 149#endif
148 150
149 nbits = ia64_fls(size + 0xfff); 151 nbits = ia64_fls(size + 0xfff);
150 while (unlikely (((1UL << nbits) & purge.mask) == 0) && (nbits < purge.max_bits)) 152 while (unlikely (((1UL << nbits) & purge.mask) == 0) &&
153 (nbits < purge.max_bits))
151 ++nbits; 154 ++nbits;
152 if (nbits > purge.max_bits) 155 if (nbits > purge.max_bits)
153 nbits = purge.max_bits; 156 nbits = purge.max_bits;
@@ -189,5 +192,5 @@ ia64_tlb_init (void)
189 local_cpu_data->ptce_stride[0] = ptce_info.stride[0]; 192 local_cpu_data->ptce_stride[0] = ptce_info.stride[0];
190 local_cpu_data->ptce_stride[1] = ptce_info.stride[1]; 193 local_cpu_data->ptce_stride[1] = ptce_info.stride[1];
191 194
192 local_flush_tlb_all(); /* nuke left overs from bootstrapping... */ 195 local_flush_tlb_all(); /* nuke left overs from bootstrapping... */
193} 196}
diff --git a/include/asm-ia64/mmu_context.h b/include/asm-ia64/mmu_context.h
index 8d9b30b5f7d..b5c65081a3a 100644
--- a/include/asm-ia64/mmu_context.h
+++ b/include/asm-ia64/mmu_context.h
@@ -7,12 +7,13 @@
7 */ 7 */
8 8
9/* 9/*
10 * Routines to manage the allocation of task context numbers. Task context numbers are 10 * Routines to manage the allocation of task context numbers. Task context
11 * used to reduce or eliminate the need to perform TLB flushes due to context switches. 11 * numbers are used to reduce or eliminate the need to perform TLB flushes
12 * Context numbers are implemented using ia-64 region ids. Since the IA-64 TLB does not 12 * due to context switches. Context numbers are implemented using ia-64
13 * consider the region number when performing a TLB lookup, we need to assign a unique 13 * region ids. Since the IA-64 TLB does not consider the region number when
14 * region id to each region in a process. We use the least significant three bits in a 14 * performing a TLB lookup, we need to assign a unique region id to each
15 * region id for this purpose. 15 * region in a process. We use the least significant three bits in aregion
16 * id for this purpose.
16 */ 17 */
17 18
18#define IA64_REGION_ID_KERNEL 0 /* the kernel's region id (tlb.c depends on this being 0) */ 19#define IA64_REGION_ID_KERNEL 0 /* the kernel's region id (tlb.c depends on this being 0) */
@@ -51,10 +52,10 @@ enter_lazy_tlb (struct mm_struct *mm, struct task_struct *tsk)
51} 52}
52 53
53/* 54/*
54 * When the context counter wraps around all TLBs need to be flushed because an old 55 * When the context counter wraps around all TLBs need to be flushed because
55 * context number might have been reused. This is signalled by the ia64_need_tlb_flush 56 * an old context number might have been reused. This is signalled by the
56 * per-CPU variable, which is checked in the routine below. Called by activate_mm(). 57 * ia64_need_tlb_flush per-CPU variable, which is checked in the routine
57 * <efocht@ess.nec.de> 58 * below. Called by activate_mm(). <efocht@ess.nec.de>
58 */ 59 */
59static inline void 60static inline void
60delayed_tlb_flush (void) 61delayed_tlb_flush (void)
@@ -64,11 +65,9 @@ delayed_tlb_flush (void)
64 65
65 if (unlikely(__ia64_per_cpu_var(ia64_need_tlb_flush))) { 66 if (unlikely(__ia64_per_cpu_var(ia64_need_tlb_flush))) {
66 spin_lock_irqsave(&ia64_ctx.lock, flags); 67 spin_lock_irqsave(&ia64_ctx.lock, flags);
67 { 68 if (__ia64_per_cpu_var(ia64_need_tlb_flush)) {
68 if (__ia64_per_cpu_var(ia64_need_tlb_flush)) { 69 local_flush_tlb_all();
69 local_flush_tlb_all(); 70 __ia64_per_cpu_var(ia64_need_tlb_flush) = 0;
70 __ia64_per_cpu_var(ia64_need_tlb_flush) = 0;
71 }
72 } 71 }
73 spin_unlock_irqrestore(&ia64_ctx.lock, flags); 72 spin_unlock_irqrestore(&ia64_ctx.lock, flags);
74 } 73 }
@@ -80,27 +79,27 @@ get_mmu_context (struct mm_struct *mm)
80 unsigned long flags; 79 unsigned long flags;
81 nv_mm_context_t context = mm->context; 80 nv_mm_context_t context = mm->context;
82 81
83 if (unlikely(!context)) { 82 if (likely(context))
84 spin_lock_irqsave(&ia64_ctx.lock, flags); 83 goto out;
85 { 84
86 /* re-check, now that we've got the lock: */ 85 spin_lock_irqsave(&ia64_ctx.lock, flags);
87 context = mm->context; 86 /* re-check, now that we've got the lock: */
88 if (context == 0) { 87 context = mm->context;
89 cpus_clear(mm->cpu_vm_mask); 88 if (context == 0) {
90 if (ia64_ctx.next >= ia64_ctx.limit) { 89 cpus_clear(mm->cpu_vm_mask);
91 ia64_ctx.next = find_next_zero_bit(ia64_ctx.bitmap, 90 if (ia64_ctx.next >= ia64_ctx.limit) {
92 ia64_ctx.max_ctx, ia64_ctx.next); 91 ia64_ctx.next = find_next_zero_bit(ia64_ctx.bitmap,
93 ia64_ctx.limit = find_next_bit(ia64_ctx.bitmap, 92 ia64_ctx.max_ctx, ia64_ctx.next);
94 ia64_ctx.max_ctx, ia64_ctx.next); 93 ia64_ctx.limit = find_next_bit(ia64_ctx.bitmap,
95 if (ia64_ctx.next >= ia64_ctx.max_ctx) 94 ia64_ctx.max_ctx, ia64_ctx.next);
96 wrap_mmu_context(mm); 95 if (ia64_ctx.next >= ia64_ctx.max_ctx)
97 } 96 wrap_mmu_context(mm);
98 mm->context = context = ia64_ctx.next++;
99 __set_bit(context, ia64_ctx.bitmap);
100 }
101 } 97 }
102 spin_unlock_irqrestore(&ia64_ctx.lock, flags); 98 mm->context = context = ia64_ctx.next++;
99 __set_bit(context, ia64_ctx.bitmap);
103 } 100 }
101 spin_unlock_irqrestore(&ia64_ctx.lock, flags);
102out:
104 /* 103 /*
105 * Ensure we're not starting to use "context" before any old 104 * Ensure we're not starting to use "context" before any old
106 * uses of it are gone from our TLB. 105 * uses of it are gone from our TLB.
@@ -111,8 +110,8 @@ get_mmu_context (struct mm_struct *mm)
111} 110}
112 111
113/* 112/*
114 * Initialize context number to some sane value. MM is guaranteed to be a brand-new 113 * Initialize context number to some sane value. MM is guaranteed to be a
115 * address-space, so no TLB flushing is needed, ever. 114 * brand-new address-space, so no TLB flushing is needed, ever.
116 */ 115 */
117static inline int 116static inline int
118init_new_context (struct task_struct *p, struct mm_struct *mm) 117init_new_context (struct task_struct *p, struct mm_struct *mm)
@@ -173,7 +172,10 @@ activate_context (struct mm_struct *mm)
173 if (!cpu_isset(smp_processor_id(), mm->cpu_vm_mask)) 172 if (!cpu_isset(smp_processor_id(), mm->cpu_vm_mask))
174 cpu_set(smp_processor_id(), mm->cpu_vm_mask); 173 cpu_set(smp_processor_id(), mm->cpu_vm_mask);
175 reload_context(context); 174 reload_context(context);
176 /* in the unlikely event of a TLB-flush by another thread, redo the load: */ 175 /*
176 * in the unlikely event of a TLB-flush by another thread,
177 * redo the load.
178 */
177 } while (unlikely(context != mm->context)); 179 } while (unlikely(context != mm->context));
178} 180}
179 181
@@ -186,8 +188,8 @@ static inline void
186activate_mm (struct mm_struct *prev, struct mm_struct *next) 188activate_mm (struct mm_struct *prev, struct mm_struct *next)
187{ 189{
188 /* 190 /*
189 * We may get interrupts here, but that's OK because interrupt handlers cannot 191 * We may get interrupts here, but that's OK because interrupt
190 * touch user-space. 192 * handlers cannot touch user-space.
191 */ 193 */
192 ia64_set_kr(IA64_KR_PT_BASE, __pa(next->pgd)); 194 ia64_set_kr(IA64_KR_PT_BASE, __pa(next->pgd));
193 activate_context(next); 195 activate_context(next);