svn commit: r216891 - head/sys/sparc64/sparc64

[Marius Strobl]

Author: marius
Date: Sun Jan  2 15:01:03 2011
New Revision: 216891
URL: http://svn.freebsd.org/changeset/base/216891

Log:
  Extend the section in which interrupts are disabled in the TLB demap
  functions, otherwise if we get preempted after checking whether a certain
  pmap is active on the current CPU but before disabling interrupts we might
  operate on an outdated state as the pmap might have been deactivated in
  the meantime. As the same issue may arises when the TLB demap function is
  interrupted by a TLB demap IPI, just entering a critical section before
  the check isn't sufficient so we have to fully disable interrupts instead.
  
  MFC after:	3 days

Modified:
  head/sys/sparc64/sparc64/tlb.c

Modified: head/sys/sparc64/sparc64/tlb.c
==============================================================================
--- head/sys/sparc64/sparc64/tlb.c	Sun Jan  2 13:31:10 2011	(r216890)
+++ head/sys/sparc64/sparc64/tlb.c	Sun Jan  2 15:01:03 2011	(r216891)
@@ -80,15 +80,15 @@ tlb_context_demap(struct pmap *pm)
 	 */
 	PMAP_STATS_INC(tlb_ncontext_demap);
 	cookie = ipi_tlb_context_demap(pm);
+	s = intr_disable();
 	if (pm->pm_active & PCPU_GET(cpumask)) {
 		KASSERT(pm->pm_context[curcpu] != -1,
 		    ("tlb_context_demap: inactive pmap?"));
-		s = intr_disable();
 		stxa(TLB_DEMAP_PRIMARY | TLB_DEMAP_CONTEXT, ASI_DMMU_DEMAP, 0);
 		stxa(TLB_DEMAP_PRIMARY | TLB_DEMAP_CONTEXT, ASI_IMMU_DEMAP, 0);
 		flush(KERNBASE);
-		intr_restore(s);
 	}
+	intr_restore(s);
 	ipi_wait(cookie);
 }
 
@@ -101,6 +101,7 @@ tlb_page_demap(struct pmap *pm, vm_offse
 
 	PMAP_STATS_INC(tlb_npage_demap);
 	cookie = ipi_tlb_page_demap(pm, va);
+	s = intr_disable();
 	if (pm->pm_active & PCPU_GET(cpumask)) {
 		KASSERT(pm->pm_context[curcpu] != -1,
 		    ("tlb_page_demap: inactive pmap?"));
@@ -109,12 +110,11 @@ tlb_page_demap(struct pmap *pm, vm_offse
 		else
 			flags = TLB_DEMAP_PRIMARY | TLB_DEMAP_PAGE;
 
-		s = intr_disable();
 		stxa(TLB_DEMAP_VA(va) | flags, ASI_DMMU_DEMAP, 0);
 		stxa(TLB_DEMAP_VA(va) | flags, ASI_IMMU_DEMAP, 0);
 		flush(KERNBASE);
-		intr_restore(s);
 	}
+	intr_restore(s);
 	ipi_wait(cookie);
 }
 
@@ -128,6 +128,7 @@ tlb_range_demap(struct pmap *pm, vm_offs
 
 	PMAP_STATS_INC(tlb_nrange_demap);
 	cookie = ipi_tlb_range_demap(pm, start, end);
+	s = intr_disable();
 	if (pm->pm_active & PCPU_GET(cpumask)) {
 		KASSERT(pm->pm_context[curcpu] != -1,
 		    ("tlb_range_demap: inactive pmap?"));
@@ -136,13 +137,12 @@ tlb_range_demap(struct pmap *pm, vm_offs
 		else
 			flags = TLB_DEMAP_PRIMARY | TLB_DEMAP_PAGE;
 
-		s = intr_disable();
 		for (va = start; va < end; va += PAGE_SIZE) {
 			stxa(TLB_DEMAP_VA(va) | flags, ASI_DMMU_DEMAP, 0);
 			stxa(TLB_DEMAP_VA(va) | flags, ASI_IMMU_DEMAP, 0);
 			flush(KERNBASE);
 		}
-		intr_restore(s);
 	}
+	intr_restore(s);
 	ipi_wait(cookie);
 }