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Diffstat (limited to 'include/linux/page-flags-layout.h')
-rw-r--r--include/linux/page-flags-layout.h92
1 files changed, 64 insertions, 28 deletions
diff --git a/include/linux/page-flags-layout.h b/include/linux/page-flags-layout.h
index 93506a114034..760006b1c480 100644
--- a/include/linux/page-flags-layout.h
+++ b/include/linux/page-flags-layout.h
@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
#ifndef PAGE_FLAGS_LAYOUT_H
#define PAGE_FLAGS_LAYOUT_H
@@ -17,18 +18,22 @@
#define ZONES_SHIFT 1
#elif MAX_NR_ZONES <= 4
#define ZONES_SHIFT 2
+#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)
+#else
+#define SECTIONS_SHIFT 0
+#endif
-#endif /* CONFIG_SPARSEMEM */
-
+#ifndef BUILD_VDSO32_64
/*
* page->flags layout:
*
@@ -38,10 +43,10 @@
* The last is when there is insufficient space in page->flags and a separate
* lookup is necessary.
*
- * No sparsemem or sparsemem vmemmap: | NODE | ZONE | ... | FLAGS |
- * " plus space for last_nid: | NODE | ZONE | LAST_NID ... | FLAGS |
- * classic sparse with space for node:| SECTION | NODE | ZONE | ... | FLAGS |
- * " plus space for last_nid: | SECTION | NODE | ZONE | LAST_NID ... | FLAGS |
+ * No sparsemem or sparsemem vmemmap: | NODE | ZONE | ... | FLAGS |
+ * " plus space for last_cpupid: | NODE | ZONE | LAST_CPUPID ... | FLAGS |
+ * classic sparse with space for node:| SECTION | NODE | ZONE | ... | FLAGS |
+ * " plus space for last_cpupid: | SECTION | NODE | ZONE | LAST_CPUPID ... | FLAGS |
* classic sparse no space for node: | SECTION | ZONE | ... | FLAGS |
*/
#if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP)
@@ -50,39 +55,70 @@
#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 + LRU_GEN_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)
+#define KASAN_TAG_WIDTH 8
+#elif defined(CONFIG_KASAN_HW_TAGS)
+#define KASAN_TAG_WIDTH 4
+#else
+#define KASAN_TAG_WIDTH 0
+#endif
+
#ifdef CONFIG_NUMA_BALANCING
-#define LAST_NID_SHIFT NODES_SHIFT
+#define LAST__PID_SHIFT 8
+#define LAST__PID_MASK ((1 << LAST__PID_SHIFT)-1)
+
+#define LAST__CPU_SHIFT NR_CPUS_BITS
+#define LAST__CPU_MASK ((1 << LAST__CPU_SHIFT)-1)
+
+#define LAST_CPUPID_SHIFT (LAST__PID_SHIFT+LAST__CPU_SHIFT)
#else
-#define LAST_NID_SHIFT 0
+#define LAST_CPUPID_SHIFT 0
#endif
-#if SECTIONS_WIDTH+ZONES_WIDTH+NODES_SHIFT+LAST_NID_SHIFT <= BITS_PER_LONG - NR_PAGEFLAGS
-#define LAST_NID_WIDTH LAST_NID_SHIFT
+#if ZONES_WIDTH + LRU_GEN_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_NID_WIDTH 0
+#define LAST_CPUPID_WIDTH 0
#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.
- */
-#if !(NODES_WIDTH > 0 || NODES_SHIFT == 0)
-#define NODE_NOT_IN_PAGE_FLAGS
+#if LAST_CPUPID_SHIFT != 0 && LAST_CPUPID_WIDTH == 0
+#define LAST_CPUPID_NOT_IN_PAGE_FLAGS
#endif
-#if defined(CONFIG_NUMA_BALANCING) && LAST_NID_WIDTH == 0
-#define LAST_NID_NOT_IN_PAGE_FLAGS
+#if ZONES_WIDTH + LRU_GEN_WIDTH + SECTIONS_WIDTH + NODES_WIDTH + \
+ KASAN_TAG_WIDTH + LAST_CPUPID_WIDTH > BITS_PER_LONG - NR_PAGEFLAGS
+#error "Not enough bits in page flags"
#endif
+/* see the comment on MAX_NR_TIERS */
+#define LRU_REFS_WIDTH min(__LRU_REFS_WIDTH, BITS_PER_LONG - NR_PAGEFLAGS - \
+ ZONES_WIDTH - LRU_GEN_WIDTH - SECTIONS_WIDTH - \
+ NODES_WIDTH - KASAN_TAG_WIDTH - LAST_CPUPID_WIDTH)
+
+#define NR_NON_PAGEFLAG_BITS (SECTIONS_WIDTH + NODES_WIDTH + ZONES_WIDTH + \
+ LAST_CPUPID_SHIFT + KASAN_TAG_WIDTH + \
+ LRU_GEN_WIDTH + LRU_REFS_WIDTH)
+
+#define NR_UNUSED_PAGEFLAG_BITS (BITS_PER_LONG - \
+ (NR_NON_PAGEFLAG_BITS + NR_PAGEFLAGS))
+
+#endif
#endif /* _LINUX_PAGE_FLAGS_LAYOUT */