[PATCH] Four level pagetables for ppc64

Implement 4-level pagetables for ppc64

This patch implements full four-level page tables for ppc64, thereby
extending the usable user address range to 44 bits (16T).

The patch uses a full page for the tables at the bottom and top level,
and a quarter page for the intermediate levels.  It uses full 64-bit
pointers at every level, thus also increasing the addressable range of
physical memory.  This patch also tweaks the VSID allocation to allow
matching range for user addresses (this halves the number of available
contexts) and adds some #if and BUILD_BUG sanity checks.

Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

1 files changed, 15 insertions, 11 deletions

diff --git a/include/asm-ppc64/page.h b/include/asm-ppc64/page.h
index a5893a305a09..7e7b18ea986e 100644
--- a/include/asm-ppc64/page.h
+++ b/include/asm-ppc64/page.h
@@ -46,6 +46,7 @@
 
 #define ARCH_HAS_HUGEPAGE_ONLY_RANGE
 #define ARCH_HAS_PREPARE_HUGEPAGE_RANGE
+#define ARCH_HAS_SETCLEAR_HUGE_PTE
 
 #define touches_hugepage_low_range(mm, addr, len) \
         (LOW_ESID_MASK((addr), (len)) & mm->context.htlb_segs)
@@ -125,36 +126,42 @@ extern void copy_user_page(void *to, void *from, unsigned long vaddr, struct pag
  * Entries in the pte table are 64b, while entries in the pgd & pmd are 32b.
  */
 typedef struct { unsigned long pte; } pte_t;
-typedef struct { unsigned int  pmd; } pmd_t;
-typedef struct { unsigned int  pgd; } pgd_t;
+typedef struct { unsigned long pmd; } pmd_t;
+typedef struct { unsigned long pud; } pud_t;
+typedef struct { unsigned long pgd; } pgd_t;
 typedef struct { unsigned long pgprot; } pgprot_t;
 
 #define pte_val(x)      ((x).pte)
 #define pmd_val(x)      ((x).pmd)
+#define pud_val(x)      ((x).pud)
 #define pgd_val(x)      ((x).pgd)
 #define pgprot_val(x)   ((x).pgprot)
 
-#define __pte(x)        ((pte_t) { (x) } )
-#define __pmd(x)        ((pmd_t) { (x) } )
-#define __pgd(x)        ((pgd_t) { (x) } )
-#define __pgprot(x)     ((pgprot_t) { (x) } )
+#define __pte(x)        ((pte_t) { (x) })
+#define __pmd(x)        ((pmd_t) { (x) })
+#define __pud(x)        ((pud_t) { (x) })
+#define __pgd(x)        ((pgd_t) { (x) })
+#define __pgprot(x)     ((pgprot_t) { (x) })
 
 #else
 /*
  * .. while these make it easier on the compiler
  */
 typedef unsigned long pte_t;
-typedef unsigned int  pmd_t;
-typedef unsigned int  pgd_t;
+typedef unsigned long pmd_t;
+typedef unsigned long pud_t;
+typedef unsigned long pgd_t;
 typedef unsigned long pgprot_t;
 
 #define pte_val(x)      (x)
 #define pmd_val(x)      (x)
+#define pud_val(x)      (x)
 #define pgd_val(x)      (x)
 #define pgprot_val(x)   (x)
 
 #define __pte(x)        (x)
 #define __pmd(x)        (x)
+#define __pud(x)        (x)
 #define __pgd(x)        (x)
 #define __pgprot(x)     (x)
 
@@ -208,9 +215,6 @@ extern u64 ppc64_pft_size;		/* Log 2 of page table size */
 #define USER_REGION_ID     (0UL)
 #define REGION_ID(ea)      (((unsigned long)(ea)) >> REGION_SHIFT)
 
-#define __bpn_to_ba(x) ((((unsigned long)(x)) << PAGE_SHIFT) + KERNELBASE)
-#define __ba_to_bpn(x) ((((unsigned long)(x)) & ~REGION_MASK) >> PAGE_SHIFT)
-
 #define __va(x) ((void *)((unsigned long)(x) + KERNELBASE))
 
 #ifdef CONFIG_DISCONTIGMEM