CRIS v10: Don't call get_mmu_context when switching between tasks with shared memory descriptors

Also, cleanup formatting and fix whitespace errors.

1 files changed, 29 insertions, 29 deletions

diff --git a/arch/cris/arch-v10/mm/tlb.c b/arch/cris/arch-v10/mm/tlb.c
index 7d9fec88dee5..6baf5bd209e7 100644
--- a/arch/cris/arch-v10/mm/tlb.c
+++ b/arch/cris/arch-v10/mm/tlb.c
@@ -4,8 +4,8 @@
  *  Low level TLB handling
  *
  *
- *  Copyright (C) 2000-2002  Axis Communications AB
- *  
+ *  Copyright (C) 2000-2007  Axis Communications AB
+ *
  *  Authors:   Bjorn Wesen (bjornw@axis.com)
  *
  */
@@ -39,7 +39,7 @@ flush_tlb_all(void)
         unsigned long flags;
 
         /* the vpn of i & 0xf is so we dont write similar TLB entries
-         * in the same 4-way entry group. details.. 
+         * in the same 4-way entry group. details...
          */
 
         local_irq_save(flags);
@@ -47,7 +47,7 @@ flush_tlb_all(void)
                 *R_TLB_SELECT = ( IO_FIELD(R_TLB_SELECT, index, i) );
                 *R_TLB_HI = ( IO_FIELD(R_TLB_HI, page_id, INVALID_PAGEID ) |
                               IO_FIELD(R_TLB_HI, vpn,     i & 0xf ) );
-                
+
                 *R_TLB_LO = ( IO_STATE(R_TLB_LO, global,no       ) |
                               IO_STATE(R_TLB_LO, valid, no       ) |
                               IO_STATE(R_TLB_LO, kernel,no       ) |
@@ -71,10 +71,10 @@ flush_tlb_mm(struct mm_struct *mm)
 
         if(page_id == NO_CONTEXT)
                 return;
-        
+
         /* mark the TLB entries that match the page_id as invalid.
          * here we could also check the _PAGE_GLOBAL bit and NOT flush
-         * global pages. is it worth the extra I/O ? 
+         * global pages. is it worth the extra I/O ?
          */
 
         local_irq_save(flags);
@@ -83,7 +83,7 @@ flush_tlb_mm(struct mm_struct *mm)
                 if (IO_EXTRACT(R_TLB_HI, page_id, *R_TLB_HI) == page_id) {
                         *R_TLB_HI = ( IO_FIELD(R_TLB_HI, page_id, INVALID_PAGEID ) |
                                       IO_FIELD(R_TLB_HI, vpn,     i & 0xf ) );
-                        
+
                         *R_TLB_LO = ( IO_STATE(R_TLB_LO, global,no  ) |
                                       IO_STATE(R_TLB_LO, valid, no  ) |
                                       IO_STATE(R_TLB_LO, kernel,no  ) |
@@ -96,9 +96,7 @@ flush_tlb_mm(struct mm_struct *mm)
 
 /* invalidate a single page */
 
-void
-flush_tlb_page(struct vm_area_struct *vma, 
-               unsigned long addr)
+void flush_tlb_page(struct vm_area_struct *vma, unsigned long addr)
 {
         struct mm_struct *mm = vma->vm_mm;
         int page_id = mm->context.page_id;
@@ -113,7 +111,7 @@ flush_tlb_page(struct vm_area_struct *vma,
         addr &= PAGE_MASK; /* perhaps not necessary */
 
         /* invalidate those TLB entries that match both the mm context
-         * and the virtual address requested 
+         * and the virtual address requested
          */
 
         local_irq_save(flags);
@@ -125,7 +123,7 @@ flush_tlb_page(struct vm_area_struct *vma,
                     (tlb_hi & PAGE_MASK) == addr) {
                         *R_TLB_HI = IO_FIELD(R_TLB_HI, page_id, INVALID_PAGEID ) |
                                 addr; /* same addr as before works. */
-                        
+
                         *R_TLB_LO = ( IO_STATE(R_TLB_LO, global,no  ) |
                                       IO_STATE(R_TLB_LO, valid, no  ) |
                                       IO_STATE(R_TLB_LO, kernel,no  ) |
@@ -144,7 +142,7 @@ dump_tlb_all(void)
 {
         int i;
         unsigned long flags;
-        
+
         printk("TLB dump. LO is: pfn | reserved | global | valid | kernel | we  |\n");
 
         local_save_flags(flags);
@@ -172,27 +170,29 @@ init_new_context(struct task_struct *tsk, struct mm_struct *mm)
 
 /* called in schedule() just before actually doing the switch_to */
 
-void 
-switch_mm(struct mm_struct *prev, struct mm_struct *next,
-          struct task_struct *tsk)
+void switch_mm(struct mm_struct *prev, struct mm_struct *next,
+        struct task_struct *tsk)
 {
-        /* make sure we have a context */
+        if (prev != next) {
+                /* make sure we have a context */
+                get_mmu_context(next);
 
-        get_mmu_context(next);
+                /* remember the pgd for the fault handlers
+                 * this is similar to the pgd register in some other CPU's.
+                 * we need our own copy of it because current and active_mm
+                 * might be invalid at points where we still need to derefer
+                 * the pgd.
+                 */
 
-        /* remember the pgd for the fault handlers
-         * this is similar to the pgd register in some other CPU's.
-         * we need our own copy of it because current and active_mm
-         * might be invalid at points where we still need to derefer
-         * the pgd.
-         */
+                per_cpu(current_pgd, smp_processor_id()) = next->pgd;
 
-        per_cpu(current_pgd, smp_processor_id()) = next->pgd;
+                /* switch context in the MMU */
 
-        /* switch context in the MMU */
-        
-        D(printk("switching mmu_context to %d (%p)\n", next->context, next));
+                D(printk(KERN_DEBUG "switching mmu_context to %d (%p)\n",
+                        next->context, next));
 
-        *R_MMU_CONTEXT = IO_FIELD(R_MMU_CONTEXT, page_id, next->context.page_id);
+                *R_MMU_CONTEXT = IO_FIELD(R_MMU_CONTEXT,
+                                          page_id, next->context.page_id);
+        }
 }