From 2c3c1048746a4622d8c89a29670120dc8fab93c4 Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Sun, 7 Apr 2024 20:49:45 +0200
Subject: Adding upstream version 6.1.76.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 include/linux/page-flags-layout.h | 115 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 115 insertions(+)
 create mode 100644 include/linux/page-flags-layout.h

(limited to 'include/linux/page-flags-layout.h')

diff --git a/include/linux/page-flags-layout.h b/include/linux/page-flags-layout.h
new file mode 100644
index 000000000..7d79818dc
--- /dev/null
+++ b/include/linux/page-flags-layout.h
@@ -0,0 +1,115 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef PAGE_FLAGS_LAYOUT_H
+#define PAGE_FLAGS_LAYOUT_H
+
+#include <linux/numa.h>
+#include <generated/bounds.h>
+
+/*
+ * When a memory allocation must conform to specific limitations (such
+ * as being suitable for DMA) the caller will pass in hints to the
+ * allocator in the gfp_mask, in the zone modifier bits.  These bits
+ * are used to select a priority ordered list of memory zones which
+ * match the requested limits. See gfp_zone() in include/linux/gfp.h
+ */
+#if MAX_NR_ZONES < 2
+#define ZONES_SHIFT 0
+#elif MAX_NR_ZONES <= 2
+#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"
+#endif
+
+#define ZONES_WIDTH		ZONES_SHIFT
+
+#ifdef CONFIG_SPARSEMEM
+#include <asm/sparsemem.h>
+#define SECTIONS_SHIFT	(MAX_PHYSMEM_BITS - SECTION_SIZE_BITS)
+#else
+#define SECTIONS_SHIFT	0
+#endif
+
+#ifndef BUILD_VDSO32_64
+/*
+ * page->flags layout:
+ *
+ * There are five possibilities for how page->flags get laid out.  The first
+ * pair is for the normal case without sparsemem. The second pair is for
+ * sparsemem when there is plenty of space for node and section information.
+ * 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_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)
+#define SECTIONS_WIDTH		SECTIONS_SHIFT
+#else
+#define SECTIONS_WIDTH		0
+#endif
+
+#if ZONES_WIDTH + LRU_GEN_WIDTH + SECTIONS_WIDTH + NODES_SHIFT \
+	<= BITS_PER_LONG - NR_PAGEFLAGS
+#define NODES_WIDTH		NODES_SHIFT
+#elif defined(CONFIG_SPARSEMEM_VMEMMAP)
+#error "Vmemmap: No space for nodes field in page flags"
+#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)
+
+#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_CPUPID_SHIFT 0
+#endif
+
+#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_CPUPID_WIDTH 0
+#endif
+
+#if LAST_CPUPID_SHIFT != 0 && LAST_CPUPID_WIDTH == 0
+#define LAST_CPUPID_NOT_IN_PAGE_FLAGS
+#endif
+
+#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)
+
+#endif
+#endif /* _LINUX_PAGE_FLAGS_LAYOUT */
-- 
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