From c947a585ab13f310c9223284dfd502790abd05f9 Mon Sep 17 00:00:00 2001 From: Johannes Weiner Date: Wed, 4 Mar 2009 16:21:30 +0100 Subject: [PATCH] xtensa: cope with ram beginning at higher addresses The current assumption of the memory code is that the first RAM PFN in the system is 0. Adjust the relevant code to play well with setups where memory starts at higher addresses, indicated by PLATFORM_DEFAULT_MEM_START. The new memory model looks like this: +----------+--+----------------------+----------------+ | | | | | | | | RAM | | | | | | | +----------+--+----------------------+----------------+ | | | | | +- PFN 0 | +- min_low_pfn +- max_low_pfn +- max_pfn | +- ARCH_PFN_OFFSET +- PLATFORM_DEFAULT_MEM_START >> PAGE_SIZE The memory map contains pages starting from pfn ARCH_PFN_OFFSET up to max_low_pfn. The only zone used right now will span exactly the same region. Usually, ARCH_PFN_OFFSET and min_low_pfn are the same value. Handle them separately for robustness. Gapping pages will be in the memory map but marked as reserved and won't be touched. Signed-off-by: Johannes Weiner Signed-off-by: Chris Zankel --- arch/xtensa/include/asm/page.h | 5 ++++- arch/xtensa/mm/init.c | 10 +++++----- 2 files changed, 9 insertions(+), 6 deletions(-) diff --git a/arch/xtensa/include/asm/page.h b/arch/xtensa/include/asm/page.h index 11f7dc2dbec7..a5a5d33c15d0 100644 --- a/arch/xtensa/include/asm/page.h +++ b/arch/xtensa/include/asm/page.h @@ -14,6 +14,7 @@ #include #include #include +#include /* * Fixed TLB translations in the processor. @@ -150,9 +151,11 @@ extern void copy_user_page(void*, void*, unsigned long, struct page*); * addresses. */ +#define ARCH_PFN_OFFSET (PLATFORM_DEFAULT_MEM_START >> PAGE_SHIFT) + #define __pa(x) ((unsigned long) (x) - PAGE_OFFSET) #define __va(x) ((void *)((unsigned long) (x) + PAGE_OFFSET)) -#define pfn_valid(pfn) ((unsigned long)pfn < max_mapnr) +#define pfn_valid(pfn) ((pfn) >= ARCH_PFN_OFFSET && ((pfn) - ARCH_PFN_OFFSET) < max_mapnr) #ifdef CONFIG_DISCONTIGMEM # error CONFIG_DISCONTIGMEM not supported #endif diff --git a/arch/xtensa/mm/init.c b/arch/xtensa/mm/init.c index a534d52a57bd..6190988bba17 100644 --- a/arch/xtensa/mm/init.c +++ b/arch/xtensa/mm/init.c @@ -167,7 +167,7 @@ void __init paging_init(void) /* All pages are DMA-able, so we put them all in the DMA zone. */ - zones_size[ZONE_DMA] = max_low_pfn; + zones_size[ZONE_DMA] = max_low_pfn - ARCH_PFN_OFFSET; for (i = 1; i < MAX_NR_ZONES; i++) zones_size[i] = 0; @@ -179,7 +179,7 @@ void __init paging_init(void) memset(swapper_pg_dir, 0, PAGE_SIZE); - free_area_init(zones_size); + free_area_init_node(0, zones_size, ARCH_PFN_OFFSET, NULL); } /* @@ -220,8 +220,8 @@ void __init mem_init(void) unsigned long codesize, reservedpages, datasize, initsize; unsigned long highmemsize, tmp, ram; - max_mapnr = num_physpages = max_low_pfn; - high_memory = (void *) __va(max_mapnr << PAGE_SHIFT); + max_mapnr = num_physpages = max_low_pfn - ARCH_PFN_OFFSET; + high_memory = (void *) __va(max_low_pfn << PAGE_SHIFT); highmemsize = 0; #ifdef CONFIG_HIGHMEM @@ -231,7 +231,7 @@ void __init mem_init(void) totalram_pages += free_all_bootmem(); reservedpages = ram = 0; - for (tmp = 0; tmp < max_low_pfn; tmp++) { + for (tmp = 0; tmp < max_mapnr; tmp++) { ram++; if (PageReserved(mem_map+tmp)) reservedpages++; -- 2.20.1