diff options
| author | Yu Zhao | 2021-04-29 23:01:07 -0700 |
|---|---|---|
| committer | Linus Torvalds | 2021-04-30 11:20:42 -0700 |
| commit | 1587db62d8c0dbd943752f657b452213e1c4d8d4 (patch) | |
| tree | bff5b8dd862605b5c26f253bed7215410e89a306 /include/linux | |
| parent | f73c6c8805ed0762d99122d5332fcf42b0c8fbb8 (diff) | |
include/linux/page-flags-layout.h: cleanups
Tidy things up and delete comments stating the obvious with typos or
making no sense.
Link: https://lkml.kernel.org/r/20210303071609.797782-2-yuzhao@google.com
Signed-off-by: Yu Zhao <yuzhao@google.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/page-flags-layout.h | 62 |
1 files changed, 29 insertions, 33 deletions
diff --git a/include/linux/page-flags-layout.h b/include/linux/page-flags-layout.h index 295c2c687d2c..ef1e3e736e14 100644 --- a/include/linux/page-flags-layout.h +++ b/include/linux/page-flags-layout.h @@ -21,16 +21,17 @@ #elif MAX_NR_ZONES <= 8 #define ZONES_SHIFT 3 #else -#error ZONES_SHIFT -- too many zones configured adjust calculation +#error ZONES_SHIFT "Too many zones configured" #endif +#define ZONES_WIDTH ZONES_SHIFT + #ifdef CONFIG_SPARSEMEM #include <asm/sparsemem.h> - -/* SECTION_SHIFT #bits space required to store a section # */ #define SECTIONS_SHIFT (MAX_PHYSMEM_BITS - SECTION_SIZE_BITS) - -#endif /* CONFIG_SPARSEMEM */ +#else +#define SECTIONS_SHIFT 0 +#endif #ifndef BUILD_VDSO32_64 /* @@ -54,17 +55,28 @@ #define SECTIONS_WIDTH 0 #endif -#define ZONES_WIDTH ZONES_SHIFT - -#if SECTIONS_WIDTH+ZONES_WIDTH+NODES_SHIFT <= BITS_PER_LONG - NR_PAGEFLAGS +#if ZONES_WIDTH + SECTIONS_WIDTH + NODES_SHIFT <= BITS_PER_LONG - NR_PAGEFLAGS #define NODES_WIDTH NODES_SHIFT -#else -#ifdef CONFIG_SPARSEMEM_VMEMMAP +#elif defined(CONFIG_SPARSEMEM_VMEMMAP) #error "Vmemmap: No space for nodes field in page flags" -#endif +#else #define NODES_WIDTH 0 #endif +/* + * Note that this #define MUST have a value so that it can be tested with + * the IS_ENABLED() macro. + */ +#if NODES_SHIFT != 0 && NODES_WIDTH == 0 +#define NODE_NOT_IN_PAGE_FLAGS 1 +#endif + +#if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS) +#define KASAN_TAG_WIDTH 8 +#else +#define KASAN_TAG_WIDTH 0 +#endif + #ifdef CONFIG_NUMA_BALANCING #define LAST__PID_SHIFT 8 #define LAST__PID_MASK ((1 << LAST__PID_SHIFT)-1) @@ -77,36 +89,20 @@ #define LAST_CPUPID_SHIFT 0 #endif -#if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS) -#define KASAN_TAG_WIDTH 8 -#else -#define KASAN_TAG_WIDTH 0 -#endif - -#if SECTIONS_WIDTH+ZONES_WIDTH+NODES_WIDTH+LAST_CPUPID_SHIFT+KASAN_TAG_WIDTH \ +#if ZONES_WIDTH + SECTIONS_WIDTH + NODES_WIDTH + KASAN_TAG_WIDTH + LAST_CPUPID_SHIFT \ <= BITS_PER_LONG - NR_PAGEFLAGS #define LAST_CPUPID_WIDTH LAST_CPUPID_SHIFT #else #define LAST_CPUPID_WIDTH 0 #endif -#if SECTIONS_WIDTH+NODES_WIDTH+ZONES_WIDTH+LAST_CPUPID_WIDTH+KASAN_TAG_WIDTH \ - > BITS_PER_LONG - NR_PAGEFLAGS -#error "Not enough bits in page flags" -#endif - -/* - * We are going to use the flags for the page to node mapping if its in - * there. This includes the case where there is no node, so it is implicit. - * Note that this #define MUST have a value so that it can be tested with - * the IS_ENABLED() macro. - */ -#if !(NODES_WIDTH > 0 || NODES_SHIFT == 0) -#define NODE_NOT_IN_PAGE_FLAGS 1 +#if LAST_CPUPID_SHIFT != 0 && LAST_CPUPID_WIDTH == 0 +#define LAST_CPUPID_NOT_IN_PAGE_FLAGS #endif -#if defined(CONFIG_NUMA_BALANCING) && LAST_CPUPID_WIDTH == 0 -#define LAST_CPUPID_NOT_IN_PAGE_FLAGS +#if ZONES_WIDTH + SECTIONS_WIDTH + NODES_WIDTH + KASAN_TAG_WIDTH + LAST_CPUPID_WIDTH \ + > BITS_PER_LONG - NR_PAGEFLAGS +#error "Not enough bits in page flags" #endif #endif |