From 6f284a2ce7b8bc49cb8455b1763357897a899abb Mon Sep 17 00:00:00 2001 From: Franck Bui-Huu Date: Wed, 10 Jan 2007 09:44:05 +0100 Subject: [PATCH] [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 Signed-off-by: Ralf Baechle --- arch/mips/kernel/setup.c | 12 ++++++++---- include/asm-mips/io.h | 4 ++-- include/asm-mips/page.h | 25 +++++++++++++++++++++---- 3 files changed, 31 insertions(+), 10 deletions(-) diff --git a/arch/mips/kernel/setup.c b/arch/mips/kernel/setup.c index f352cd9c83..e1d76b8760 100644 --- a/arch/mips/kernel/setup.c +++ b/arch/mips/kernel/setup.c @@ -315,13 +315,17 @@ static void __init bootmem_init(void) if (min_low_pfn >= max_low_pfn) panic("Incorrect memory mapping !!!"); - if (min_low_pfn > 0) { + if (min_low_pfn > ARCH_PFN_OFFSET) { printk(KERN_INFO "Wasting %lu bytes for tracking %lu unused pages\n", - min_low_pfn * sizeof(struct page), - min_low_pfn); - min_low_pfn = 0; + (min_low_pfn - ARCH_PFN_OFFSET) * sizeof(struct page), + min_low_pfn - ARCH_PFN_OFFSET); + } else if (min_low_pfn < ARCH_PFN_OFFSET) { + printk(KERN_INFO + "%lu free pages won't be used\n", + ARCH_PFN_OFFSET - min_low_pfn); } + min_low_pfn = ARCH_PFN_OFFSET; /* * Determine low and high memory ranges diff --git a/include/asm-mips/io.h b/include/asm-mips/io.h index d77b657c09..67f0810789 100644 --- a/include/asm-mips/io.h +++ b/include/asm-mips/io.h @@ -115,7 +115,7 @@ static inline void set_io_port_base(unsigned long base) */ static inline unsigned long virt_to_phys(volatile const void *address) { - return (unsigned long)address - PAGE_OFFSET; + return (unsigned long)address - PAGE_OFFSET + PHYS_OFFSET; } /* @@ -132,7 +132,7 @@ static inline unsigned long virt_to_phys(volatile const void *address) */ static inline void * phys_to_virt(unsigned long address) { - return (void *)(address + PAGE_OFFSET); + return (void *)(address + PAGE_OFFSET - PHYS_OFFSET); } /* diff --git a/include/asm-mips/page.h b/include/asm-mips/page.h index 2f9e1a9ec5..d3fbd83ff5 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 #include @@ -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) -- 2.39.5