Stephen, Andrew, On Monday 06 January 2014 12:28 PM, Russell King wrote: > On Mon, Jan 06, 2014 at 08:07:58PM +1100, Stephen Rothwell wrote: >> Hi Andrew, >> >> After merging the akpm-current tree, today's linux-next build (arm >> multi_v7_defconfig) failed like this: >> >> arch/arm/mm/init.c:199:13: error: conflicting types for 'arm_dma_zone_size' >> include/linux/bootmem.h:259:11: note: previous declaration of 'arm_dma_zone_size' was here >> >> Caused by commit a3ae9362fafe ("mm/memblock: add memblock memory >> allocation apis"). >> >> For this build, BOOTMEM_LOW_LIMIT is defined as __pa(MAX_DMA_ADDRESS) and >> MAX_DMA_ADDRESS is defined as: >> >> #define MAX_DMA_ADDRESS ({ \ >> extern unsigned long arm_dma_zone_size; \ >> arm_dma_zone_size ? \ >> (PAGE_OFFSET + arm_dma_zone_size) : 0xffffffffUL; }) >> >> and in arch/arm/mm/init.c, arm_dma_zone_size is declared as: >> >> phys_addr_t arm_dma_zone_size __read_mostly; >> >> Urk! :-( >> >> OK, so commit 364230b995214 ("ARM: use phys_addr_t for DMA zone sizes") >> changed the definition of arm_dma_zone_size except it missed the one in >> arch/arm/include/asm/dma.h. >> >> I have applied this merge fix patch for today: > > There's more here than just this change required here. We also need to > limit it if PAGE_OFFSET + arm_dma_zone_size is greater than 4GB, as > MAX_DMA_ADDRESS is a virtual address - we really don't want the 32-bit > value of this wrapping. > > Exactly how we go about this, I'm not sure at the moment, but maybe > something like this: > > #define MAX_DMA_ADDRESS ({ \ > extern phys_addr_t arm_dma_zone_size; \ > arm_dma_zone_size && arm_dma_zone_size < (0x10000000 - PAGE_OFFSET) ? \ > (PAGE_OFFSET + arm_dma_zone_size) : 0xffffffffUL; }) > Here is the patch as per the discussion. I have merged Steven's patch and update suggested by Russell. Also attaching it, in case mailer eats tabs. >From 779ab1fdaffbd7a4c8b3bba41f7a84c666c0c24e Mon Sep 17 00:00:00 2001 From: Russell King Date: Mon, 6 Jan 2014 16:57:36 -0500 Subject: [PATCH] ARM: mm: change further appearance of arm_dma_zone_size to phys_addr_t The definition was chagned in commit 364230b995214 ("ARM: use phys_addr_t for DMA zone sizes"). Fixes this build error: arch/arm/mm/init.c:199:13: error: conflicting types for 'arm_dma_zone_size' include/linux/bootmem.h:259:11: note: previous declaration of 'arm_dma_zone_size' was here While changing the type, we also need to limit MAX_DMA_ADDRESS if PAGE_OFFSET + arm_dma_zone_size is greater than 4GB. The MAX_DMA_ADDRESS is a virtual address and we really don't want the 32-bit value of this wrapping. Cc: Stephen Rothwell Cc: Andrew Morton Signed-off-by: Santosh Shilimkar Signed-off-by: Russell King --- arch/arm/include/asm/dma.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/arch/arm/include/asm/dma.h b/arch/arm/include/asm/dma.h index 58b8c6a..9908443 100644 --- a/arch/arm/include/asm/dma.h +++ b/arch/arm/include/asm/dma.h @@ -8,8 +8,8 @@ #define MAX_DMA_ADDRESS 0xffffffffUL #else #define MAX_DMA_ADDRESS ({ \ - extern unsigned long arm_dma_zone_size; \ - arm_dma_zone_size ? \ + extern phys_addr_t arm_dma_zone_size; \ + arm_dma_zone_size && arm_dma_zone_size < (0x10000000 - PAGE_OFFSET) ? \ (PAGE_OFFSET + arm_dma_zone_size) : 0xffffffffUL; }) #endif -- 1.7.9.5