x86: change flush_tlb_others to take a const struct cpumask
Impact: reduce stack usage, use new cpumask API.
This is made a little more tricky by uv_flush_tlb_others which
actually alters its argument, for an IPI to be sent to the remaining
cpus in the mask.
I solve this by allocating a cpumask_var_t for this case and falling back
to IPI should this fail.
To eliminate temporaries in the caller, all flush_tlb_others implementations
now do the this-cpu-elimination step themselves.
Note also the curious "cpus_or(f->flush_cpumask, cpumask, f->flush_cpumask)"
which has been there since pre-git and yet f->flush_cpumask is always zero
at this point.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Mike Travis <travis@sgi.com>
diff --git a/arch/x86/kernel/tlb_64.c b/arch/x86/kernel/tlb_64.c
index f8be6f1..38836ae 100644
--- a/arch/x86/kernel/tlb_64.c
+++ b/arch/x86/kernel/tlb_64.c
@@ -43,10 +43,10 @@
union smp_flush_state {
struct {
- cpumask_t flush_cpumask;
struct mm_struct *flush_mm;
unsigned long flush_va;
spinlock_t tlbstate_lock;
+ DECLARE_BITMAP(flush_cpumask, NR_CPUS);
};
char pad[SMP_CACHE_BYTES];
} ____cacheline_aligned;
@@ -131,7 +131,7 @@
sender = ~regs->orig_ax - INVALIDATE_TLB_VECTOR_START;
f = &per_cpu(flush_state, sender);
- if (!cpu_isset(cpu, f->flush_cpumask))
+ if (!cpumask_test_cpu(cpu, to_cpumask(f->flush_cpumask)))
goto out;
/*
* This was a BUG() but until someone can quote me the
@@ -153,19 +153,15 @@
}
out:
ack_APIC_irq();
- cpu_clear(cpu, f->flush_cpumask);
+ cpumask_clear_cpu(cpu, to_cpumask(f->flush_cpumask));
inc_irq_stat(irq_tlb_count);
}
-void native_flush_tlb_others(const cpumask_t *cpumaskp, struct mm_struct *mm,
- unsigned long va)
+static void flush_tlb_others_ipi(const struct cpumask *cpumask,
+ struct mm_struct *mm, unsigned long va)
{
int sender;
union smp_flush_state *f;
- cpumask_t cpumask = *cpumaskp;
-
- if (is_uv_system() && uv_flush_tlb_others(&cpumask, mm, va))
- return;
/* Caller has disabled preemption */
sender = smp_processor_id() % NUM_INVALIDATE_TLB_VECTORS;
@@ -180,7 +176,8 @@
f->flush_mm = mm;
f->flush_va = va;
- cpus_or(f->flush_cpumask, cpumask, f->flush_cpumask);
+ cpumask_andnot(to_cpumask(f->flush_cpumask),
+ cpumask, cpumask_of(smp_processor_id()));
/*
* Make the above memory operations globally visible before
@@ -191,9 +188,9 @@
* We have to send the IPI only to
* CPUs affected.
*/
- send_IPI_mask(&cpumask, INVALIDATE_TLB_VECTOR_START + sender);
+ send_IPI_mask(cpumask, INVALIDATE_TLB_VECTOR_START + sender);
- while (!cpus_empty(f->flush_cpumask))
+ while (!cpumask_empty(to_cpumask(f->flush_cpumask)))
cpu_relax();
f->flush_mm = NULL;
@@ -201,6 +198,24 @@
spin_unlock(&f->tlbstate_lock);
}
+void native_flush_tlb_others(const struct cpumask *cpumask,
+ struct mm_struct *mm, unsigned long va)
+{
+ if (is_uv_system()) {
+ cpumask_var_t after_uv_flush;
+
+ if (alloc_cpumask_var(&after_uv_flush, GFP_ATOMIC)) {
+ cpumask_andnot(after_uv_flush,
+ cpumask, cpumask_of(smp_processor_id()));
+ if (!uv_flush_tlb_others(after_uv_flush, mm, va))
+ flush_tlb_others_ipi(after_uv_flush, mm, va);
+ free_cpumask_var(after_uv_flush);
+ return;
+ }
+ }
+ flush_tlb_others_ipi(cpumask, mm, va);
+}
+
static int __cpuinit init_smp_flush(void)
{
int i;
@@ -215,25 +230,18 @@
void flush_tlb_current_task(void)
{
struct mm_struct *mm = current->mm;
- cpumask_t cpu_mask;
preempt_disable();
- cpu_mask = mm->cpu_vm_mask;
- cpu_clear(smp_processor_id(), cpu_mask);
local_flush_tlb();
- if (!cpus_empty(cpu_mask))
- flush_tlb_others(cpu_mask, mm, TLB_FLUSH_ALL);
+ if (cpumask_any_but(&mm->cpu_vm_mask, smp_processor_id()) < nr_cpu_ids)
+ flush_tlb_others(&mm->cpu_vm_mask, mm, TLB_FLUSH_ALL);
preempt_enable();
}
void flush_tlb_mm(struct mm_struct *mm)
{
- cpumask_t cpu_mask;
-
preempt_disable();
- cpu_mask = mm->cpu_vm_mask;
- cpu_clear(smp_processor_id(), cpu_mask);
if (current->active_mm == mm) {
if (current->mm)
@@ -241,8 +249,8 @@
else
leave_mm(smp_processor_id());
}
- if (!cpus_empty(cpu_mask))
- flush_tlb_others(cpu_mask, mm, TLB_FLUSH_ALL);
+ if (cpumask_any_but(&mm->cpu_vm_mask, smp_processor_id()) < nr_cpu_ids)
+ flush_tlb_others(&mm->cpu_vm_mask, mm, TLB_FLUSH_ALL);
preempt_enable();
}
@@ -250,11 +258,8 @@
void flush_tlb_page(struct vm_area_struct *vma, unsigned long va)
{
struct mm_struct *mm = vma->vm_mm;
- cpumask_t cpu_mask;
preempt_disable();
- cpu_mask = mm->cpu_vm_mask;
- cpu_clear(smp_processor_id(), cpu_mask);
if (current->active_mm == mm) {
if (current->mm)
@@ -263,8 +268,8 @@
leave_mm(smp_processor_id());
}
- if (!cpus_empty(cpu_mask))
- flush_tlb_others(cpu_mask, mm, va);
+ if (cpumask_any_but(&mm->cpu_vm_mask, smp_processor_id()) < nr_cpu_ids)
+ flush_tlb_others(&mm->cpu_vm_mask, mm, va);
preempt_enable();
}