Merge branch 'master'

1 files changed, 26 insertions, 69 deletions

diff --git a/arch/sparc64/kernel/smp.c b/arch/sparc64/kernel/smp.c
index b137fd63f5e1..797a65493fb8 100644
--- a/arch/sparc64/kernel/smp.c
+++ b/arch/sparc64/kernel/smp.c
@@ -168,6 +168,9 @@ void __init smp_callin(void)
                 rmb();
 
         cpu_set(cpuid, cpu_online_map);
+
+        /* idle thread is expected to have preempt disabled */
+        preempt_disable();
 }
 
 void cpu_panic(void)
@@ -839,43 +842,29 @@ void smp_flush_tlb_all(void)
  *    questionable (in theory the big win for threads is the massive sharing of
  *    address space state across processors).
  */
+
+/* This currently is only used by the hugetlb arch pre-fault
+ * hook on UltraSPARC-III+ and later when changing the pagesize
+ * bits of the context register for an address space.
+ */
 void smp_flush_tlb_mm(struct mm_struct *mm)
 {
-        /*
-         * This code is called from two places, dup_mmap and exit_mmap. In the
-         * former case, we really need a flush. In the later case, the callers
-         * are single threaded exec_mmap (really need a flush), multithreaded
-         * exec_mmap case (do not need to flush, since the caller gets a new
-         * context via activate_mm), and all other callers of mmput() whence
-         * the flush can be optimized since the associated threads are dead and
-         * the mm is being torn down (__exit_mm and other mmput callers) or the
-         * owning thread is dissociating itself from the mm. The
-         * (atomic_read(&mm->mm_users) == 0) check ensures real work is done
-         * for single thread exec and dup_mmap cases. An alternate check might
-         * have been (current->mm != mm).
-         *                                              Kanoj Sarcar
-         */
-        if (atomic_read(&mm->mm_users) == 0)
-                return;
-
-        {
-                u32 ctx = CTX_HWBITS(mm->context);
-                int cpu = get_cpu();
+        u32 ctx = CTX_HWBITS(mm->context);
+        int cpu = get_cpu();
 
-                if (atomic_read(&mm->mm_users) == 1) {
-                        mm->cpu_vm_mask = cpumask_of_cpu(cpu);
-                        goto local_flush_and_out;
-                }
+        if (atomic_read(&mm->mm_users) == 1) {
+                mm->cpu_vm_mask = cpumask_of_cpu(cpu);
+                goto local_flush_and_out;
+        }
 
-                smp_cross_call_masked(&xcall_flush_tlb_mm,
-                                      ctx, 0, 0,
-                                      mm->cpu_vm_mask);
+        smp_cross_call_masked(&xcall_flush_tlb_mm,
+                              ctx, 0, 0,
+                              mm->cpu_vm_mask);
 
-        local_flush_and_out:
-                __flush_tlb_mm(ctx, SECONDARY_CONTEXT);
+local_flush_and_out:
+        __flush_tlb_mm(ctx, SECONDARY_CONTEXT);
 
-                put_cpu();
-        }
+        put_cpu();
 }
 
 void smp_flush_tlb_pending(struct mm_struct *mm, unsigned long nr, unsigned long *vaddrs)
@@ -883,34 +872,13 @@ void smp_flush_tlb_pending(struct mm_struct *mm, unsigned long nr, unsigned long
         u32 ctx = CTX_HWBITS(mm->context);
         int cpu = get_cpu();
 
-        if (mm == current->active_mm && atomic_read(&mm->mm_users) == 1) {
+        if (mm == current->active_mm && atomic_read(&mm->mm_users) == 1)
                 mm->cpu_vm_mask = cpumask_of_cpu(cpu);
-                goto local_flush_and_out;
-        } else {
-                /* This optimization is not valid.  Normally
-                 * we will be holding the page_table_lock, but
-                 * there is an exception which is copy_page_range()
-                 * when forking.  The lock is held during the individual
-                 * page table updates in the parent, but not at the
-                 * top level, which is where we are invoked.
-                 */
-                if (0) {
-                        cpumask_t this_cpu_mask = cpumask_of_cpu(cpu);
-
-                        /* By virtue of running under the mm->page_table_lock,
-                         * and mmu_context.h:switch_mm doing the same, the
-                         * following operation is safe.
-                         */
-                        if (cpus_equal(mm->cpu_vm_mask, this_cpu_mask))
-                                goto local_flush_and_out;
-                }
-        }
-
-        smp_cross_call_masked(&xcall_flush_tlb_pending,
-                              ctx, nr, (unsigned long) vaddrs,
-                              mm->cpu_vm_mask);
+        else
+                smp_cross_call_masked(&xcall_flush_tlb_pending,
+                                      ctx, nr, (unsigned long) vaddrs,
+                                      mm->cpu_vm_mask);
 
-local_flush_and_out:
         __flush_tlb_pending(ctx, nr, vaddrs);
 
         put_cpu();
@@ -1184,20 +1152,9 @@ void __init smp_cpus_done(unsigned int max_cpus)
                (bogosum/(5000/HZ))%100);
 }
 
-/* This needn't do anything as we do not sleep the cpu
- * inside of the idler task, so an interrupt is not needed
- * to get a clean fast response.
- *
- * XXX Reverify this assumption... -DaveM
- *
- * Addendum: We do want it to do something for the signal
- *           delivery case, we detect that by just seeing
- *           if we are trying to send this to an idler or not.
- */
 void smp_send_reschedule(int cpu)
 {
-        if (cpu_data(cpu).idle_volume == 0)
-                smp_receive_signal(cpu);
+        smp_receive_signal(cpu);
 }
 
 /* This is a nop because we capture all other cpus