diff options
| author | Ilya Yanok <yanok@emcraft.com> | 2008-12-11 02:55:41 +0100 |
|---|---|---|
| committer | Paul Mackerras <paulus@samba.org> | 2008-12-28 23:53:25 +0100 |
| commit | ca9153a3a2a7556d091dfe080e42b0e67881fff6 (patch) | |
| tree | 35b5ce24f190690cf7a726cbb97980da51704855 /arch/powerpc/include/asm/highmem.h | |
| parent | powerpc: Force memory size to be a multiple of PAGE_SIZE (diff) | |
| download | linux-ca9153a3a2a7556d091dfe080e42b0e67881fff6.tar.xz linux-ca9153a3a2a7556d091dfe080e42b0e67881fff6.zip | |
powerpc/44x: Support 16K/64K base page sizes on 44x
This adds support for 16k and 64k page sizes on PowerPC 44x processors.
The PGDIR table is much smaller than a page when using 16k or 64k
pages (512 and 32 bytes respectively) so we allocate the PGDIR with
kzalloc() instead of __get_free_pages().
One PTE table covers rather a large memory area when using 16k or 64k
pages (32MB or 512MB respectively), so we can easily put FIXMAP and
PKMAP in the area covered by one PTE table.
Signed-off-by: Yuri Tikhonov <yur@emcraft.com>
Signed-off-by: Vladimir Panfilov <pvr@emcraft.com>
Signed-off-by: Ilya Yanok <yanok@emcraft.com>
Acked-by: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
Diffstat (limited to 'arch/powerpc/include/asm/highmem.h')
| -rw-r--r-- | arch/powerpc/include/asm/highmem.h | 19 |
1 files changed, 17 insertions, 2 deletions
diff --git a/arch/powerpc/include/asm/highmem.h b/arch/powerpc/include/asm/highmem.h index fd97e501aa6a..04e4a620952e 100644 --- a/arch/powerpc/include/asm/highmem.h +++ b/arch/powerpc/include/asm/highmem.h @@ -38,9 +38,24 @@ extern pte_t *pkmap_page_table; * easily, subsequent pte tables have to be allocated in one physical * chunk of RAM. */ -#define LAST_PKMAP (1 << PTE_SHIFT) -#define LAST_PKMAP_MASK (LAST_PKMAP-1) +/* + * We use one full pte table with 4K pages. And with 16K/64K pages pte + * table covers enough memory (32MB and 512MB resp.) that both FIXMAP + * and PKMAP can be placed in single pte table. We use 1024 pages for + * PKMAP in case of 16K/64K pages. + */ +#ifdef CONFIG_PPC_4K_PAGES +#define PKMAP_ORDER PTE_SHIFT +#else +#define PKMAP_ORDER 10 +#endif +#define LAST_PKMAP (1 << PKMAP_ORDER) +#ifndef CONFIG_PPC_4K_PAGES +#define PKMAP_BASE (FIXADDR_START - PAGE_SIZE*(LAST_PKMAP + 1)) +#else #define PKMAP_BASE ((FIXADDR_START - PAGE_SIZE*(LAST_PKMAP + 1)) & PMD_MASK) +#endif +#define LAST_PKMAP_MASK (LAST_PKMAP-1) #define PKMAP_NR(virt) ((virt-PKMAP_BASE) >> PAGE_SHIFT) #define PKMAP_ADDR(nr) (PKMAP_BASE + ((nr) << PAGE_SHIFT)) |