diff options
Diffstat (limited to 'target/linux/bcm27xx/patches-5.4/950-0437-mm-refresh-ZONE_DMA-and-ZONE_DMA32-comments-in-enum-.patch')
| -rw-r--r-- | target/linux/bcm27xx/patches-5.4/950-0437-mm-refresh-ZONE_DMA-and-ZONE_DMA32-comments-in-enum-.patch | 84 |
1 files changed, 0 insertions, 84 deletions
diff --git a/target/linux/bcm27xx/patches-5.4/950-0437-mm-refresh-ZONE_DMA-and-ZONE_DMA32-comments-in-enum-.patch b/target/linux/bcm27xx/patches-5.4/950-0437-mm-refresh-ZONE_DMA-and-ZONE_DMA32-comments-in-enum-.patch deleted file mode 100644 index 23811e0b6e..0000000000 --- a/target/linux/bcm27xx/patches-5.4/950-0437-mm-refresh-ZONE_DMA-and-ZONE_DMA32-comments-in-enum-.patch +++ /dev/null @@ -1,84 +0,0 @@ -From 1c108eaeae73a504ac1b2d882bc1fefb91eecf17 Mon Sep 17 00:00:00 2001 -From: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> -Date: Wed, 11 Sep 2019 20:25:46 +0200 -Subject: [PATCH] mm: refresh ZONE_DMA and ZONE_DMA32 comments in 'enum - zone_type' - -commit 734f9246e791d8da278957b2c326d7709b2a97c0 upstream. - -These zones usage has evolved with time and the comments were outdated. -This joins both ZONE_DMA and ZONE_DMA32 explanation and gives up to date -examples on how they are used on different architectures. - -Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de> -Reviewed-by: Christoph Hellwig <hch@lst.de> -Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> -Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> ---- - include/linux/mmzone.h | 45 ++++++++++++++++++++++++------------------ - 1 file changed, 26 insertions(+), 19 deletions(-) - ---- a/include/linux/mmzone.h -+++ b/include/linux/mmzone.h -@@ -358,33 +358,40 @@ struct per_cpu_nodestat { - #endif /* !__GENERATING_BOUNDS.H */ - - enum zone_type { --#ifdef CONFIG_ZONE_DMA - /* -- * ZONE_DMA is used when there are devices that are not able -- * to do DMA to all of addressable memory (ZONE_NORMAL). Then we -- * carve out the portion of memory that is needed for these devices. -- * The range is arch specific. -- * -- * Some examples -- * -- * Architecture Limit -- * --------------------------- -- * parisc, ia64, sparc <4G -- * s390, powerpc <2G -- * arm Various -- * alpha Unlimited or 0-16MB. -+ * ZONE_DMA and ZONE_DMA32 are used when there are peripherals not able -+ * to DMA to all of the addressable memory (ZONE_NORMAL). -+ * On architectures where this area covers the whole 32 bit address -+ * space ZONE_DMA32 is used. ZONE_DMA is left for the ones with smaller -+ * DMA addressing constraints. This distinction is important as a 32bit -+ * DMA mask is assumed when ZONE_DMA32 is defined. Some 64-bit -+ * platforms may need both zones as they support peripherals with -+ * different DMA addressing limitations. -+ * -+ * Some examples: -+ * -+ * - i386 and x86_64 have a fixed 16M ZONE_DMA and ZONE_DMA32 for the -+ * rest of the lower 4G. -+ * -+ * - arm only uses ZONE_DMA, the size, up to 4G, may vary depending on -+ * the specific device. -+ * -+ * - arm64 has a fixed 1G ZONE_DMA and ZONE_DMA32 for the rest of the -+ * lower 4G. -+ * -+ * - powerpc only uses ZONE_DMA, the size, up to 2G, may vary -+ * depending on the specific device. - * -- * i386, x86_64 and multiple other arches -- * <16M. -+ * - s390 uses ZONE_DMA fixed to the lower 2G. -+ * -+ * - ia64 and riscv only use ZONE_DMA32. -+ * -+ * - parisc uses neither. - */ -+#ifdef CONFIG_ZONE_DMA - ZONE_DMA, - #endif - #ifdef CONFIG_ZONE_DMA32 -- /* -- * x86_64 needs two ZONE_DMAs because it supports devices that are -- * only able to do DMA to the lower 16M but also 32 bit devices that -- * can only do DMA areas below 4G. -- */ - ZONE_DMA32, - #endif - /* |