diff options
| author | Logan Gunthorpe <logang@deltatee.com> | 2018-12-14 14:16:53 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-12-14 15:05:45 -0800 |
| commit | d1402fc708e4c355813e49df6d15bc3466ba5114 (patch) | |
| tree | fab18217bc25d21ed1a1b507cdf427d1c69b5db4 | |
| parent | 5b5260902af4cf7d2b8da06ba395a722f6d490fa (diff) | |
mm: introduce common STRUCT_PAGE_MAX_SHIFT define
This define is used by arm64 to calculate the size of the vmemmap
region. It is defined as the log2 of the upper bound on the size of a
struct page.
We move it into mm_types.h so it can be defined properly instead of set
and checked with a build bug. This also allows us to use the same
define for riscv.
Link: http://lkml.kernel.org/r/20181107205433.3875-2-logang@deltatee.com
Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Acked-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | arch/arm64/include/asm/memory.h | 9 | ||||
| -rw-r--r-- | arch/arm64/mm/init.c | 8 | ||||
| -rw-r--r-- | include/asm-generic/fixmap.h | 1 | ||||
| -rw-r--r-- | include/linux/mm_types.h | 5 |
4 files changed, 6 insertions, 17 deletions
diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h index b96442960aea..f0a5c9531e8b 100644 --- a/arch/arm64/include/asm/memory.h +++ b/arch/arm64/include/asm/memory.h @@ -35,15 +35,6 @@ #define PCI_IO_SIZE SZ_16M /* - * Log2 of the upper bound of the size of a struct page. Used for sizing - * the vmemmap region only, does not affect actual memory footprint. - * We don't use sizeof(struct page) directly since taking its size here - * requires its definition to be available at this point in the inclusion - * chain, and it may not be a power of 2 in the first place. - */ -#define STRUCT_PAGE_MAX_SHIFT 6 - -/* * VMEMMAP_SIZE - allows the whole linear region to be covered by * a struct page array */ diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c index 9b432d9fcada..0340e45655c6 100644 --- a/arch/arm64/mm/init.c +++ b/arch/arm64/mm/init.c @@ -610,14 +610,6 @@ void __init mem_init(void) BUILD_BUG_ON(TASK_SIZE_32 > TASK_SIZE_64); #endif -#ifdef CONFIG_SPARSEMEM_VMEMMAP - /* - * Make sure we chose the upper bound of sizeof(struct page) - * correctly when sizing the VMEMMAP array. - */ - BUILD_BUG_ON(sizeof(struct page) > (1 << STRUCT_PAGE_MAX_SHIFT)); -#endif - if (PAGE_SIZE >= 16384 && get_num_physpages() <= 128) { extern int sysctl_overcommit_memory; /* diff --git a/include/asm-generic/fixmap.h b/include/asm-generic/fixmap.h index 827e4d3bbc7a..8cc7b09c1bc7 100644 --- a/include/asm-generic/fixmap.h +++ b/include/asm-generic/fixmap.h @@ -16,6 +16,7 @@ #define __ASM_GENERIC_FIXMAP_H #include <linux/bug.h> +#include <linux/mm_types.h> #define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT)) #define __virt_to_fix(x) ((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT) diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 5ed8f6292a53..2c471a2c43fa 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -206,6 +206,11 @@ struct page { #endif } _struct_page_alignment; +/* + * Used for sizing the vmemmap region on some architectures + */ +#define STRUCT_PAGE_MAX_SHIFT (order_base_2(sizeof(struct page))) + #define PAGE_FRAG_CACHE_MAX_SIZE __ALIGN_MASK(32768, ~PAGE_MASK) #define PAGE_FRAG_CACHE_MAX_ORDER get_order(PAGE_FRAG_CACHE_MAX_SIZE) |