powerpc: Whitespace/comment changes to tlb_low_64e.S

I happened to comment this code while I was digging through it;
we might as well commit that.  I also made some whitespace
changes - the existing code had a lot of unnecessary newlines
that I found annoying when I was working on my tiny laptop.

No functional changes.

Signed-off-by: Becky Bruce <beckyb@kernel.crashing.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

1 files changed, 11 insertions, 17 deletions

diff --git a/arch/powerpc/mm/tlb_low_64e.S b/arch/powerpc/mm/tlb_low_64e.S
index dc4a5f385e41..71d5d9a0b220 100644
--- a/arch/powerpc/mm/tlb_low_64e.S
+++ b/arch/powerpc/mm/tlb_low_64e.S
@@ -94,11 +94,11 @@
 
         srdi    r15,r16,60              /* get region */
         rldicl. r10,r16,64-PGTABLE_EADDR_SIZE,PGTABLE_EADDR_SIZE+4
-        bne-    dtlb_miss_fault_bolted
+        bne-    dtlb_miss_fault_bolted  /* Bail if fault addr is invalid */
 
         rlwinm  r10,r11,32-19,27,27
         rlwimi  r10,r11,32-16,19,19
-        cmpwi   r15,0
+        cmpwi   r15,0                   /* user vs kernel check */
         ori     r10,r10,_PAGE_PRESENT
         oris    r11,r10,_PAGE_ACCESSED@h
 
@@ -120,44 +120,38 @@ tlb_miss_common_bolted:
         rldicl  r15,r16,64-PGDIR_SHIFT+3,64-PGD_INDEX_SIZE-3
         cmpldi  cr0,r14,0
         clrrdi  r15,r15,3
-        beq     tlb_miss_fault_bolted
+        beq     tlb_miss_fault_bolted   /* No PGDIR, bail */
 
 BEGIN_MMU_FTR_SECTION
         /* Set the TLB reservation and search for existing entry. Then load
          * the entry.
          */
         PPC_TLBSRX_DOT(0,r16)
-        ldx     r14,r14,r15
-        beq     normal_tlb_miss_done
+        ldx     r14,r14,r15             /* grab pgd entry */
+        beq     normal_tlb_miss_done    /* tlb exists already, bail */
 MMU_FTR_SECTION_ELSE
-        ldx     r14,r14,r15
+        ldx     r14,r14,r15             /* grab pgd entry */
 ALT_MMU_FTR_SECTION_END_IFSET(MMU_FTR_USE_TLBRSRV)
 
 #ifndef CONFIG_PPC_64K_PAGES
         rldicl  r15,r16,64-PUD_SHIFT+3,64-PUD_INDEX_SIZE-3
         clrrdi  r15,r15,3
-
-        cmpldi  cr0,r14,0
-        beq     tlb_miss_fault_bolted
-
-        ldx     r14,r14,r15
+        cmlpdi  cr0,r14,0
+        beq     tlb_miss_fault_bolted   /* Bad pgd entry */
+        ldx     r14,r14,r15             /* grab pud entry */
 #endif /* CONFIG_PPC_64K_PAGES */
 
         rldicl  r15,r16,64-PMD_SHIFT+3,64-PMD_INDEX_SIZE-3
         clrrdi  r15,r15,3
-
         cmpldi  cr0,r14,0
         beq     tlb_miss_fault_bolted
-
-        ldx     r14,r14,r15
+        ldx     r14,r14,r15             /* Grab pmd entry */
 
         rldicl  r15,r16,64-PAGE_SHIFT+3,64-PTE_INDEX_SIZE-3
         clrrdi  r15,r15,3
-
         cmpldi  cr0,r14,0
         beq     tlb_miss_fault_bolted
-
-        ldx     r14,r14,r15
+        ldx     r14,r14,r15             /* Grab PTE */
 
         /* Check if required permissions are met */
         andc.   r15,r11,r14