parisc: allow to build with 16k default kernel page size

Introduce new convert_for_tlb_insert20 macro and use it to replace assembler
statements with hardcoded constants.
This change allows the parisc64 kernel to boot with 16kb default kernel page size,
aka CONFIG_PARISC_PAGE_SIZE_16KB=y.

Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>

1 files changed, 17 insertions, 8 deletions

diff --git a/arch/parisc/kernel/entry.S b/arch/parisc/kernel/entry.S
index 0f7ff938b06a..4e9dd15e076c 100644
--- a/arch/parisc/kernel/entry.S
+++ b/arch/parisc/kernel/entry.S
@@ -505,6 +505,18 @@
         STREG           \pte,0(\ptep)
         .endm
 
+        /* bitshift difference between a PFN (based on kernel's PAGE_SIZE)
+         * to a CPU TLB 4k PFN (4k => 12 bits to shift) */
+        #define PAGE_ADD_SHIFT  (PAGE_SHIFT-12)
+
+        /* Drop prot bits and convert to page addr for iitlbt and idtlbt */
+        .macro          convert_for_tlb_insert20 pte
+        extrd,u         \pte,(63-ASM_PFN_PTE_SHIFT)+(63-58)+PAGE_ADD_SHIFT,\
+                                64-PAGE_SHIFT-PAGE_ADD_SHIFT,\pte
+        depdi           _PAGE_SIZE_ENCODING_DEFAULT,63,\
+                                (63-58)+PAGE_ADD_SHIFT,\pte
+        .endm
+
         /* Convert the pte and prot to tlb insertion values.  How
          * this happens is quite subtle, read below */
         .macro          make_insert_tlb spc,pte,prot
@@ -544,8 +556,7 @@
         depi            1,12,1,\prot
 
         /* Drop prot bits and convert to page addr for iitlbt and idtlbt */
-        extrd,u         \pte,(63-ASM_PFN_PTE_SHIFT)+(63-58),64-PAGE_SHIFT,\pte
-        depdi           _PAGE_SIZE_ENCODING_DEFAULT,63,63-58,\pte
+        convert_for_tlb_insert20 \pte
         .endm
 
         /* Identical macro to make_insert_tlb above, except it
@@ -1244,10 +1255,9 @@ nadtlb_check_flush_20w:
         depdi,z         7,7,3,prot
         depdi           1,10,1,prot
 
-        /* Get rid of prot bits and convert to page addr for idtlbt */
+        /* Drop prot bits from pte and convert to page addr for idtlbt */
+        convert_for_tlb_insert20 pte
 
-        depdi           0,63,12,pte
-        extrd,u         pte,56,52,pte
         idtlbt          pte,prot
 
         rfir
@@ -1403,10 +1413,9 @@ nadtlb_check_flush_20:
         depdi,z         7,7,3,prot
         depdi           1,10,1,prot
 
-        /* Get rid of prot bits and convert to page addr for idtlbt */
+        /* Drop prot bits from pte and convert to page addr for idtlbt */
+        convert_for_tlb_insert20 pte
 
-        depdi           0,63,12,pte
-        extrd,u         pte,56,32,pte
         idtlbt          pte,prot
 
         rfir