From 60296c71f6c5063e3c1f1d2619ca0b60940162e7 Mon Sep 17 00:00:00 2001 From: Lennert Buytenhek Date: Tue, 5 Aug 2008 01:56:13 +0200 Subject: [ARM] prevent crashing when too much RAM installed This patch will truncate and/or ignore memory banks if their kernel direct mappings would (partially) overlap with the vmalloc area or the mappings between the vmalloc area and the address space top, to prevent crashing during early boot if there happens to be more RAM installed than we are expecting. Since the start of the vmalloc area is not at a fixed address (but the vmalloc end address is, via the per-platform VMALLOC_END define), a default area of 128M is reserved for vmalloc mappings, which can be shrunk or enlarged by passing an appropriate vmalloc= command line option as it is done on x86. On a board with a 3:1 user:kernel split, VMALLOC_END at 0xfe000000, two 512M RAM banks and vmalloc=128M (the default), this patch gives: Truncating RAM at 20000000-3fffffff to -35ffffff (vmalloc region overlap). Memory: 512MB 352MB = 864MB total On a board with a 3:1 user:kernel split, VMALLOC_END at 0xfe800000, two 256M RAM banks and vmalloc=768M, this patch gives: Truncating RAM at 00000000-0fffffff to -0e7fffff (vmalloc region overlap). Ignoring RAM at 10000000-1fffffff (vmalloc region overlap). Signed-off-by: Lennert Buytenhek Tested-by: Riku Voipio --- arch/arm/include/asm/memory.h | 8 ++++++++ 1 file changed, 8 insertions(+) (limited to 'arch/arm/include/asm/memory.h') diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h index 1e070a2b561a..7bcd69a9a88c 100644 --- a/arch/arm/include/asm/memory.h +++ b/arch/arm/include/asm/memory.h @@ -149,6 +149,14 @@ #define arch_adjust_zones(node,size,holes) do { } while (0) #endif +/* + * Amount of memory reserved for the vmalloc() area, and minimum + * address for vmalloc mappings. + */ +extern unsigned long vmalloc_reserve; + +#define VMALLOC_MIN (void *)(VMALLOC_END - vmalloc_reserve) + /* * PFNs are used to describe any physical page; this means * PFN 0 == physical address 0. -- cgit v1.2.1 From 98ed7d4b1a4eebc1ac25929b6968673bef4d54c3 Mon Sep 17 00:00:00 2001 From: Russell King Date: Sun, 10 Aug 2008 12:10:49 +0100 Subject: [ARM] dma-mapping: improve type-safeness of DMA translations OMAP at least gets the return type(s) for the DMA translation functions wrong, which can lead to subtle errors. Avoid this by moving the DMA translation functions to asm/dma-mapping.h, and converting them to inline functions. Fix the OMAP DMA translation macros to use the correct argument and result types. Also, remove the unnecessary casts in dmabounce.c. Signed-off-by: Russell King --- arch/arm/include/asm/memory.h | 14 -------------- 1 file changed, 14 deletions(-) (limited to 'arch/arm/include/asm/memory.h') diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h index 7bcd69a9a88c..bf7c737c9226 100644 --- a/arch/arm/include/asm/memory.h +++ b/arch/arm/include/asm/memory.h @@ -313,20 +313,6 @@ static inline __deprecated void *bus_to_virt(unsigned long x) */ #define page_to_phys(page) (page_to_pfn(page) << PAGE_SHIFT) -/* - * Optional device DMA address remapping. Do _not_ use directly! - * We should really eliminate virt_to_bus() here - it's deprecated. - */ -#ifndef __arch_page_to_dma -#define page_to_dma(dev, page) ((dma_addr_t)__virt_to_bus((unsigned long)page_address(page))) -#define dma_to_virt(dev, addr) ((void *)__bus_to_virt(addr)) -#define virt_to_dma(dev, addr) ((dma_addr_t)__virt_to_bus((unsigned long)(addr))) -#else -#define page_to_dma(dev, page) (__arch_page_to_dma(dev, page)) -#define dma_to_virt(dev, addr) (__arch_dma_to_virt(dev, addr)) -#define virt_to_dma(dev, addr) (__arch_virt_to_dma(dev, addr)) -#endif - /* * Optional coherency support. Currently used only by selected * Intel XSC3-based systems. -- cgit v1.2.1