From 2d5a5612bceda8edd25b29f363c4e2c6cda28bab Mon Sep 17 00:00:00 2001 From: Catalin Marinas Date: Fri, 13 Jun 2014 13:41:20 +0100 Subject: [PATCH] arm64: Limit the CMA buffer to 32-bit if ZONE_DMA When the CMA buffer is allocated, it is too early to know whether devices will require ZONE_DMA memory. This patch limits the CMA buffer to (DMA_BIT_MASK(32) + 1) if CONFIG_ZONE_DMA is enabled. In addition, it computes the dma_to_phys(DMA_BIT_MASK(32)) before the increment (no current functional change). Signed-off-by: Catalin Marinas --- arch/arm64/mm/init.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-) diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index 091d428d64ac..f43db8a69262 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -71,7 +71,7 @@ static void __init zone_sizes_init(unsigned long min, unsigned long max) /* 4GB maximum for 32-bit only capable devices */ if (IS_ENABLED(CONFIG_ZONE_DMA)) { unsigned long max_dma_phys = - (unsigned long)dma_to_phys(NULL, DMA_BIT_MASK(32) + 1); + (unsigned long)(dma_to_phys(NULL, DMA_BIT_MASK(32)) + 1); max_dma = max(min, min(max, max_dma_phys >> PAGE_SHIFT)); zone_size[ZONE_DMA] = max_dma - min; } @@ -126,6 +126,8 @@ static void arm64_memory_present(void) void __init arm64_memblock_init(void) { + phys_addr_t dma_phys_limit = 0; + /* Register the kernel text, kernel data and initrd with memblock */ memblock_reserve(__pa(_text), _end - _text); #ifdef CONFIG_BLK_DEV_INITRD @@ -141,7 +143,11 @@ void __init arm64_memblock_init(void) memblock_reserve(__pa(idmap_pg_dir), IDMAP_DIR_SIZE); early_init_fdt_scan_reserved_mem(); - dma_contiguous_reserve(0); + + /* 4GB maximum for 32-bit only capable devices */ + if (IS_ENABLED(CONFIG_ZONE_DMA)) + dma_phys_limit = dma_to_phys(NULL, DMA_BIT_MASK(32)) + 1; + dma_contiguous_reserve(dma_phys_limit); memblock_allow_resize(); memblock_dump_all(); -- 2.20.1