leandrof/linux
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

sparc64: Move to 64-bit PGDs and PMDs.

Browse Source 
To make the page tables compact, we were using 32-bit PGDs and PMDs.
We only had to support <= 43 bits of physical addresses so this was
quite feasible.

In order to support larger physical addresses we have to move to
64-bit PGDs and PMDs.

Most of the changes are straight-forward:

1) {pgd,pmd}_t --> unsigned long

2) Anything that tries to use plain "unsigned int" types with pgd/pmd
   values needs to be adjusted.  In particular things like "0U" become
   "0UL".

3) {PGDIR,PMD}_BITS decrease by one.

4) In the assembler page table walkers, use "ldxa" instead of "lduwa"
   and adjust the low bit masks to clear out the low 3 bits instead of
   just the low 2 bits during pgd/pmd address formation.

Also, use PTRS_PER_PGD and PTRS_PER_PMD in the sizing of the
swapper_{pg_dir,low_pmd_dir} arrays.

This patch does not try to take advantage of having 64-bits in the
PMDs to simplify the hugepage code, that will come in a subsequent
change.

Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
David S. Miller
2013-09-25 14:33:16 -07:00
parent 37b3a8ff3e
commit 2b77933c28
4 changed files with 34 additions and 31 deletions
Download Patch File Download Diff File Expand all files Collapse all files

25
arch/sparc/include/asm/page_64.h
View File

@@ -56,8 +56,8 @@ extern void copy_user_page(void *to, void *from, unsigned long vaddr, struct pag
/* These are used to make use of C type-checking.. */
typedef struct { unsigned long pte; } pte_t;
typedef struct { unsigned long iopte; } iopte_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 pgd; } pgd_t;
typedef struct { unsigned long pgprot; } pgprot_t;
#define pte_val(x) ((x).pte)
@@ -76,8 +76,8 @@ typedef struct { unsigned long pgprot; } pgprot_t;
/* .. while these make it easier on the compiler */
typedef unsigned long pte_t;
typedef unsigned long iopte_t;
typedef unsigned int pmd_t;
typedef unsigned int pgd_t;
typedef unsigned long pmd_t;
typedef unsigned long pgd_t;
typedef unsigned long pgprot_t;
#define pte_val(x) (x)
@@ -97,15 +97,18 @@ typedef unsigned long pgprot_t;
typedef pte_t *pgtable_t;
/* These two values define the virtual address space range in which we
* must forbid 64-bit user processes from making mappings. It
* represents the virtual address space hole present in most early
* sparc64 chips including UltraSPARC-I. The next two defines specify
* the actual exclusion region we enforce, wherein we use a 4GB red
* zone on each side of the VA hole.
* must forbid 64-bit user processes from making mappings. It used to
* represent precisely the virtual address space hole present in most
* early sparc64 chips including UltraSPARC-I. But now it also is
* further constrained by the limits of our page tables, which is
* 43-bits of virtual address.
*/
#define SPARC64_VA_HOLE_TOP _AC(0xfffff80000000000,UL)
#define SPARC64_VA_HOLE_BOTTOM _AC(0x0000080000000000,UL)
#define SPARC64_VA_HOLE_TOP _AC(0xfffffc0000000000,UL)
#define SPARC64_VA_HOLE_BOTTOM _AC(0x0000040000000000,UL)
/* The next two defines specify the actual exclusion region we
* enforce, wherein we use a 4GB red zone on each side of the VA hole.
*/
#define VA_EXCLUDE_START (SPARC64_VA_HOLE_BOTTOM - (1UL << 32UL))
#define VA_EXCLUDE_END (SPARC64_VA_HOLE_TOP + (1UL << 32UL))