sparc64: Document PGD and PMD layout.
David Miller [Mon, 8 Oct 2012 23:34:23 +0000 (16:34 -0700)]
We're going to be messing around with the PMD interpretation and layout
for the sake of transparent huge pages, so we better clearly document what
we're starting with.

Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

arch/sparc/include/asm/pgtable_64.h
arch/sparc/include/asm/tsb.h

index a7b5091..af3cd7a 100644 (file)
 #error Page table parameters do not cover virtual address space properly.
 #endif
 
+/* PMDs point to PTE tables which are 4K aligned.  */
+#define PMD_PADDR      _AC(0xfffffffe,UL)
+#define PMD_PADDR_SHIFT        _AC(11,UL)
+
+/* PGDs point to PMD tables which are 8K aligned.  */
+#define PGD_PADDR      _AC(0xfffffffc,UL)
+#define PGD_PADDR_SHIFT        _AC(11,UL)
+
 #ifndef __ASSEMBLY__
 
 #include <linux/sched.h>
@@ -581,14 +589,14 @@ static inline unsigned long pte_special(pte_t pte)
 }
 
 #define pmd_set(pmdp, ptep)    \
-       (pmd_val(*(pmdp)) = (__pa((unsigned long) (ptep)) >> 11UL))
+       (pmd_val(*(pmdp)) = (__pa((unsigned long) (ptep)) >> PMD_PADDR_SHIFT))
 #define pud_set(pudp, pmdp)    \
-       (pud_val(*(pudp)) = (__pa((unsigned long) (pmdp)) >> 11UL))
+       (pud_val(*(pudp)) = (__pa((unsigned long) (pmdp)) >> PGD_PADDR_SHIFT))
 #define __pmd_page(pmd)                \
-       ((unsigned long) __va((((unsigned long)pmd_val(pmd))<<11UL)))
+       ((unsigned long) __va((((unsigned long)pmd_val(pmd))<<PMD_PADDR_SHIFT)))
 #define pmd_page(pmd)                  virt_to_page((void *)__pmd_page(pmd))
 #define pud_page_vaddr(pud)            \
-       ((unsigned long) __va((((unsigned long)pud_val(pud))<<11UL)))
+       ((unsigned long) __va((((unsigned long)pud_val(pud))<<PGD_PADDR_SHIFT)))
 #define pud_page(pud)                  virt_to_page((void *)pud_page_vaddr(pud))
 #define pmd_none(pmd)                  (!pmd_val(pmd))
 #define pmd_bad(pmd)                   (0)
index 6435924..ef8cd1a 100644 (file)
@@ -147,13 +147,13 @@ extern struct tsb_phys_patch_entry __tsb_phys_patch, __tsb_phys_patch_end;
        brz,pn          REG1, FAIL_LABEL; \
         sllx           VADDR, 64 - (PMD_SHIFT + PMD_BITS), REG2; \
        srlx            REG2, 64 - PAGE_SHIFT, REG2; \
-       sllx            REG1, 11, REG1; \
+       sllx            REG1, PGD_PADDR_SHIFT, REG1; \
        andn            REG2, 0x3, REG2; \
        lduwa           [REG1 + REG2] ASI_PHYS_USE_EC, REG1; \
        brz,pn          REG1, FAIL_LABEL; \
         sllx           VADDR, 64 - PMD_SHIFT, REG2; \
        srlx            REG2, 64 - (PAGE_SHIFT - 1), REG2; \
-       sllx            REG1, 11, REG1; \
+       sllx            REG1, PMD_PADDR_SHIFT, REG1; \
        andn            REG2, 0x7, REG2; \
        add             REG1, REG2, REG1;
 
@@ -172,13 +172,13 @@ extern struct tsb_phys_patch_entry __tsb_phys_patch, __tsb_phys_patch_end;
        brz,pn          REG1, FAIL_LABEL; \
         sllx           VADDR, 64 - (PMD_SHIFT + PMD_BITS), REG2; \
        srlx            REG2, 64 - PAGE_SHIFT, REG2; \
-       sllx            REG1, 11, REG1; \
+       sllx            REG1, PGD_PADDR_SHIFT, REG1; \
        andn            REG2, 0x3, REG2; \
        lduwa           [REG1 + REG2] ASI_PHYS_USE_EC, REG1; \
        brz,pn          REG1, FAIL_LABEL; \
         sllx           VADDR, 64 - PMD_SHIFT, REG2; \
        srlx            REG2, 64 - (PAGE_SHIFT - 1), REG2; \
-       sllx            REG1, 11, REG1; \
+       sllx            REG1, PMD_PADDR_SHIFT, REG1; \
        andn            REG2, 0x7, REG2; \
        add             REG1, REG2, REG1;