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powerpc/44x: Support 16K/64K base page sizes on 44x

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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>
This commit is contained in:
Ilya Yanok
2008-12-11 04:55:41 +03:00
committed by Paul Mackerras
parent 6ca4f7494b
commit ca9153a3a2
10 changed files with 130 additions and 48 deletions
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19
arch/powerpc/include/asm/highmem.h
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@@ -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))