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| author |   Franck Bui-Huu <fbuihuu@gmail.com> | 2007-01-10 09:44:05 +0100 |
|---|---|---|
| committer |   Ralf Baechle <ralf@linux-mips.org> | 2007-02-06 16:53:13 +0000 |
| commit | 6f284a2ce7b8bc49cb8455b1763357897a899abb (patch) | |
| tree | abf59702fad617780f59594aa8939db7ec4c76d6 /include/asm-mips/page.h | |
| parent | [MIPS] Setup min_low_pfn/max_low_pfn correctly (diff) | |
| download | linux-dev-6f284a2ce7b8bc49cb8455b1763357897a899abb.tar.xz linux-dev-6f284a2ce7b8bc49cb8455b1763357897a899abb.zip | |
[MIPS] FLATMEM: introduce PHYS_OFFSET.
The old code was assuming that min_low_pfn was always 0. This
means that platforms having a big hole at their memory start
paid the price of wasting some memory for the allocation of
unused entries in mem_map[].
This patch prevents this waste.
It introduces PHYS_OFFSET define which is the start of the
physical memory and uses it wherever needed. Specially when
converting physical/virtual addresses into virtual/physical
ones.
Currently all platforms defines PHYS_OFFSET to 0.
Signed-off-by: Franck Bui-Huu <fbuihuu@gmail.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Diffstat (limited to '')
| -rw-r--r-- | include/asm-mips/page.h | 25 |
1 files changed, 21 insertions, 4 deletions
diff --git a/include/asm-mips/page.h b/include/asm-mips/page.h index 2f9e1a9ec51f..d3fbd83ff545 100644 --- a/include/asm-mips/page.h +++ b/include/asm-mips/page.h @@ -34,6 +34,20 @@ #ifndef __ASSEMBLY__ +/* + * This gives the physical RAM offset. + */ +#ifndef PHYS_OFFSET +#define PHYS_OFFSET 0UL +#endif + +/* + * It's normally defined only for FLATMEM config but it's + * used in our early mem init code for all memory models. + * So always define it. + */ +#define ARCH_PFN_OFFSET PFN_UP(PHYS_OFFSET) + #include <linux/pfn.h> #include <asm/io.h> @@ -132,20 +146,23 @@ typedef struct { unsigned long pgprot; } pgprot_t; /* to align the pointer to the (next) page boundary */ #define PAGE_ALIGN(addr) (((addr) + PAGE_SIZE - 1) & PAGE_MASK) +/* + * __pa()/__va() should be used only during mem init. + */ #if defined(CONFIG_64BIT) && !defined(CONFIG_BUILD_ELF64) #define __pa_page_offset(x) ((unsigned long)(x) < CKSEG0 ? PAGE_OFFSET : CKSEG0) #else #define __pa_page_offset(x) PAGE_OFFSET #endif -#define __pa(x) ((unsigned long)(x) - __pa_page_offset(x)) -#define __pa_symbol(x) __pa(RELOC_HIDE((unsigned long)(x),0)) -#define __va(x) ((void *)((unsigned long)(x) + PAGE_OFFSET)) +#define __pa(x) ((unsigned long)(x) - __pa_page_offset(x) + PHYS_OFFSET) +#define __va(x) ((void *)((unsigned long)(x) + PAGE_OFFSET - PHYS_OFFSET)) +#define __pa_symbol(x) __pa(RELOC_HIDE((unsigned long)(x),0)) #define pfn_to_kaddr(pfn) __va((pfn) << PAGE_SHIFT) #ifdef CONFIG_FLATMEM -#define pfn_valid(pfn) ((pfn) < max_mapnr) +#define pfn_valid(pfn) ((pfn) >= ARCH_PFN_OFFSET && (pfn) < max_mapnr) #elif defined(CONFIG_SPARSEMEM) |