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authorChen, Kenneth W <kenneth.w.chen@intel.com>2005-10-29 18:47:04 -0700
committerTony Luck <tony.luck@intel.com>2005-11-03 14:43:50 -0800
commit58cd90829918dabbd81a453de676d41fb7b628ad (patch)
tree7806f84a89f767f3a9e78d0e198054f24fae0aee /include/asm-ia64
parent[IA64] Use bitmaps for efficient context allocation/free (diff)
downloadlinux-dev-58cd90829918dabbd81a453de676d41fb7b628ad.tar.xz
linux-dev-58cd90829918dabbd81a453de676d41fb7b628ad.zip
[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>
Diffstat (limited to 'include/asm-ia64')
-rw-r--r--include/asm-ia64/mmu_context.h80
1 files changed, 41 insertions, 39 deletions
diff --git a/include/asm-ia64/mmu_context.h b/include/asm-ia64/mmu_context.h
index 8d9b30b5f7d4..b5c65081a3aa 100644
--- a/include/asm-ia64/mmu_context.h
+++ b/include/asm-ia64/mmu_context.h
@@ -7,12 +7,13 @@
*/
/*
- * Routines to manage the allocation of task context numbers. Task context numbers are
- * used to reduce or eliminate the need to perform TLB flushes due to context switches.
- * Context numbers are implemented using ia-64 region ids. Since the IA-64 TLB does not
- * consider the region number when performing a TLB lookup, we need to assign a unique
- * region id to each region in a process. We use the least significant three bits in a
- * region id for this purpose.
+ * Routines to manage the allocation of task context numbers. Task context
+ * numbers are used to reduce or eliminate the need to perform TLB flushes
+ * due to context switches. Context numbers are implemented using ia-64
+ * region ids. Since the IA-64 TLB does not consider the region number when
+ * performing a TLB lookup, we need to assign a unique region id to each
+ * region in a process. We use the least significant three bits in aregion
+ * id for this purpose.
*/
#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)
}
/*
- * When the context counter wraps around all TLBs need to be flushed because an old
- * context number might have been reused. This is signalled by the ia64_need_tlb_flush
- * per-CPU variable, which is checked in the routine below. Called by activate_mm().
- * <efocht@ess.nec.de>
+ * When the context counter wraps around all TLBs need to be flushed because
+ * an old context number might have been reused. This is signalled by the
+ * ia64_need_tlb_flush per-CPU variable, which is checked in the routine
+ * below. Called by activate_mm(). <efocht@ess.nec.de>
*/
static inline void
delayed_tlb_flush (void)
@@ -64,11 +65,9 @@ delayed_tlb_flush (void)
if (unlikely(__ia64_per_cpu_var(ia64_need_tlb_flush))) {
spin_lock_irqsave(&ia64_ctx.lock, flags);
- {
- if (__ia64_per_cpu_var(ia64_need_tlb_flush)) {
- local_flush_tlb_all();
- __ia64_per_cpu_var(ia64_need_tlb_flush) = 0;
- }
+ if (__ia64_per_cpu_var(ia64_need_tlb_flush)) {
+ local_flush_tlb_all();
+ __ia64_per_cpu_var(ia64_need_tlb_flush) = 0;
}
spin_unlock_irqrestore(&ia64_ctx.lock, flags);
}
@@ -80,27 +79,27 @@ get_mmu_context (struct mm_struct *mm)
unsigned long flags;
nv_mm_context_t context = mm->context;
- if (unlikely(!context)) {
- spin_lock_irqsave(&ia64_ctx.lock, flags);
- {
- /* re-check, now that we've got the lock: */
- context = mm->context;
- if (context == 0) {
- cpus_clear(mm->cpu_vm_mask);
- if (ia64_ctx.next >= ia64_ctx.limit) {
- ia64_ctx.next = find_next_zero_bit(ia64_ctx.bitmap,
- ia64_ctx.max_ctx, ia64_ctx.next);
- ia64_ctx.limit = find_next_bit(ia64_ctx.bitmap,
- ia64_ctx.max_ctx, ia64_ctx.next);
- if (ia64_ctx.next >= ia64_ctx.max_ctx)
- wrap_mmu_context(mm);
- }
- mm->context = context = ia64_ctx.next++;
- __set_bit(context, ia64_ctx.bitmap);
- }
+ if (likely(context))
+ goto out;
+
+ spin_lock_irqsave(&ia64_ctx.lock, flags);
+ /* re-check, now that we've got the lock: */
+ context = mm->context;
+ if (context == 0) {
+ cpus_clear(mm->cpu_vm_mask);
+ if (ia64_ctx.next >= ia64_ctx.limit) {
+ ia64_ctx.next = find_next_zero_bit(ia64_ctx.bitmap,
+ ia64_ctx.max_ctx, ia64_ctx.next);
+ ia64_ctx.limit = find_next_bit(ia64_ctx.bitmap,
+ ia64_ctx.max_ctx, ia64_ctx.next);
+ if (ia64_ctx.next >= ia64_ctx.max_ctx)
+ wrap_mmu_context(mm);
}
- spin_unlock_irqrestore(&ia64_ctx.lock, flags);
+ mm->context = context = ia64_ctx.next++;
+ __set_bit(context, ia64_ctx.bitmap);
}
+ spin_unlock_irqrestore(&ia64_ctx.lock, flags);
+out:
/*
* Ensure we're not starting to use "context" before any old
* uses of it are gone from our TLB.
@@ -111,8 +110,8 @@ get_mmu_context (struct mm_struct *mm)
}
/*
- * Initialize context number to some sane value. MM is guaranteed to be a brand-new
- * address-space, so no TLB flushing is needed, ever.
+ * Initialize context number to some sane value. MM is guaranteed to be a
+ * brand-new address-space, so no TLB flushing is needed, ever.
*/
static inline int
init_new_context (struct task_struct *p, struct mm_struct *mm)
@@ -173,7 +172,10 @@ activate_context (struct mm_struct *mm)
if (!cpu_isset(smp_processor_id(), mm->cpu_vm_mask))
cpu_set(smp_processor_id(), mm->cpu_vm_mask);
reload_context(context);
- /* in the unlikely event of a TLB-flush by another thread, redo the load: */
+ /*
+ * in the unlikely event of a TLB-flush by another thread,
+ * redo the load.
+ */
} while (unlikely(context != mm->context));
}
@@ -186,8 +188,8 @@ static inline void
activate_mm (struct mm_struct *prev, struct mm_struct *next)
{
/*
- * We may get interrupts here, but that's OK because interrupt handlers cannot
- * touch user-space.
+ * We may get interrupts here, but that's OK because interrupt
+ * handlers cannot touch user-space.
*/
ia64_set_kr(IA64_KR_PT_BASE, __pa(next->pgd));
activate_context(next);