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>

1 files changed, 8 insertions, 8 deletions

diff --git a/arch/x86/kernel/tlb_uv.c b/arch/x86/kernel/tlb_uv.c
index f885023167e0..690dcf1a27d4 100644
--- a/arch/x86/kernel/tlb_uv.c
+++ b/arch/x86/kernel/tlb_uv.c
@@ -212,11 +212,11 @@ static int uv_wait_completion(struct bau_desc *bau_desc,
  * The cpumaskp mask contains the cpus the broadcast was sent to.
  *
  * Returns 1 if all remote flushing was done. The mask is zeroed.
- * Returns 0 if some remote flushing remains to be done. The mask is left
- * unchanged.
+ * Returns 0 if some remote flushing remains to be done. The mask will have
+ * some bits still set.
  */
 int uv_flush_send_and_wait(int cpu, int this_blade, struct bau_desc *bau_desc,
-                           cpumask_t *cpumaskp)
+                           struct cpumask *cpumaskp)
 {
         int completion_status = 0;
         int right_shift;
@@ -263,13 +263,13 @@ int uv_flush_send_and_wait(int cpu, int this_blade, struct bau_desc *bau_desc,
          * Success, so clear the remote cpu's from the mask so we don't
          * use the IPI method of shootdown on them.
          */
-        for_each_cpu_mask(bit, *cpumaskp) {
+        for_each_cpu(bit, cpumaskp) {
                 blade = uv_cpu_to_blade_id(bit);
                 if (blade == this_blade)
                         continue;
-                cpu_clear(bit, *cpumaskp);
+                cpumask_clear_cpu(bit, cpumaskp);
         }
-        if (!cpus_empty(*cpumaskp))
+        if (!cpumask_empty(cpumaskp))
                 return 0;
         return 1;
 }
@@ -296,7 +296,7 @@ int uv_flush_send_and_wait(int cpu, int this_blade, struct bau_desc *bau_desc,
  * Returns 1 if all remote flushing was done.
  * Returns 0 if some remote flushing remains to be done.
  */
-int uv_flush_tlb_others(cpumask_t *cpumaskp, struct mm_struct *mm,
+int uv_flush_tlb_others(struct cpumask *cpumaskp, struct mm_struct *mm,
                         unsigned long va)
 {
         int i;
@@ -315,7 +315,7 @@ int uv_flush_tlb_others(cpumask_t *cpumaskp, struct mm_struct *mm,
         bau_nodes_clear(&bau_desc->distribution, UV_DISTRIBUTION_SIZE);
 
         i = 0;
-        for_each_cpu_mask(bit, *cpumaskp) {
+        for_each_cpu(bit, cpumaskp) {
                 blade = uv_cpu_to_blade_id(bit);
                 BUG_ON(blade > (UV_DISTRIBUTION_SIZE - 1));
                 if (blade == this_blade) {