[PATCH v2 01/11] asm-generic: add dma_zone_size
From: Nicolas Saenz Julienne <hidden>
Date: 2019-08-20 14:58:32
Also in:
linux-arch, linux-arm-kernel, linux-iommu, linux-riscv, lkml
Subsystem:
generic include/asm header files, memory management, memory management - page allocator, the rest · Maintainers:
Arnd Bergmann, Andrew Morton, Vlastimil Babka, Linus Torvalds
Some architectures have platform specific DMA addressing limitations. This will allow for hardware description code to provide the constraints in a generic manner, so as for arch code to properly setup it's memory zones and DMA mask. Signed-off-by: Nicolas Saenz Julienne <redacted> --- Changes in v2: None include/asm-generic/dma.h | 8 +++++++- mm/page_alloc.c | 3 +++ 2 files changed, 10 insertions(+), 1 deletion(-)
diff --git a/include/asm-generic/dma.h b/include/asm-generic/dma.h
index 43d0c8af8058..c2f39cdb64f6 100644
--- a/include/asm-generic/dma.h
+++ b/include/asm-generic/dma.h@@ -8,7 +8,13 @@ * * Some code relies on seeing MAX_DMA_ADDRESS though. */ -#define MAX_DMA_ADDRESS PAGE_OFFSET +#define MAX_DMA_ADDRESS (PAGE_OFFSET + dma_zone_size) + +/* + * Some architectures may have platform specific DMA addressing constraints. + * Firmware can use this to fine tune the device's DMA memory zone. + */ +extern u64 dma_zone_size __ro_after_init; extern int request_dma(unsigned int dmanr, const char *device_id); extern void free_dma(unsigned int dmanr);
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 272c6de1bf4e..b514afee5451 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c@@ -133,6 +133,9 @@ EXPORT_SYMBOL(_totalram_pages); unsigned long totalreserve_pages __read_mostly; unsigned long totalcma_pages __read_mostly; +u64 dma_zone_size __ro_after_init; +EXPORT_SYMBOL(dma_zone_size); + int percpu_pagelist_fraction; gfp_t gfp_allowed_mask __read_mostly = GFP_BOOT_MASK; #ifdef CONFIG_INIT_ON_ALLOC_DEFAULT_ON
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2.22.0