Adding upstream version 4.19.249.upstream/4.19.249upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 119 insertions, 0 deletions

diff --git a/drivers/block/zram/zram_drv.h b/drivers/block/zram/zram_drv.h
new file mode 100644
index 000000000..d1095dfdf
--- /dev/null
+++ b/drivers/block/zram/zram_drv.h
@@ -0,0 +1,119 @@
+/*
+ * Compressed RAM block device
+ *
+ * Copyright (C) 2008, 2009, 2010  Nitin Gupta
+ *               2012, 2013 Minchan Kim
+ *
+ * This code is released using a dual license strategy: BSD/GPL
+ * You can choose the licence that better fits your requirements.
+ *
+ * Released under the terms of 3-clause BSD License
+ * Released under the terms of GNU General Public License Version 2.0
+ *
+ */
+
+#ifndef _ZRAM_DRV_H_
+#define _ZRAM_DRV_H_
+
+#include <linux/rwsem.h>
+#include <linux/zsmalloc.h>
+#include <linux/crypto.h>
+
+#include "zcomp.h"
+
+#define SECTORS_PER_PAGE_SHIFT	(PAGE_SHIFT - SECTOR_SHIFT)
+#define SECTORS_PER_PAGE	(1 << SECTORS_PER_PAGE_SHIFT)
+#define ZRAM_LOGICAL_BLOCK_SHIFT 12
+#define ZRAM_LOGICAL_BLOCK_SIZE	(1 << ZRAM_LOGICAL_BLOCK_SHIFT)
+#define ZRAM_SECTOR_PER_LOGICAL_BLOCK	\
+	(1 << (ZRAM_LOGICAL_BLOCK_SHIFT - SECTOR_SHIFT))
+
+
+/*
+ * The lower ZRAM_FLAG_SHIFT bits of table.value is for
+ * object size (excluding header), the higher bits is for
+ * zram_pageflags.
+ *
+ * zram is mainly used for memory efficiency so we want to keep memory
+ * footprint small so we can squeeze size and flags into a field.
+ * The lower ZRAM_FLAG_SHIFT bits is for object size (excluding header),
+ * the higher bits is for zram_pageflags.
+ */
+#define ZRAM_FLAG_SHIFT 24
+
+/* Flags for zram pages (table[page_no].value) */
+enum zram_pageflags {
+	/* zram slot is locked */
+	ZRAM_LOCK = ZRAM_FLAG_SHIFT,
+	ZRAM_SAME,	/* Page consists the same element */
+	ZRAM_WB,	/* page is stored on backing_device */
+	ZRAM_HUGE,	/* Incompressible page */
+
+	__NR_ZRAM_PAGEFLAGS,
+};
+
+/*-- Data structures */
+
+/* Allocated for each disk page */
+struct zram_table_entry {
+	union {
+		unsigned long handle;
+		unsigned long element;
+	};
+	unsigned long value;
+#ifdef CONFIG_ZRAM_MEMORY_TRACKING
+	ktime_t ac_time;
+#endif
+};
+
+struct zram_stats {
+	atomic64_t compr_data_size;	/* compressed size of pages stored */
+	atomic64_t num_reads;	/* failed + successful */
+	atomic64_t num_writes;	/* --do-- */
+	atomic64_t failed_reads;	/* can happen when memory is too low */
+	atomic64_t failed_writes;	/* can happen when memory is too low */
+	atomic64_t invalid_io;	/* non-page-aligned I/O requests */
+	atomic64_t notify_free;	/* no. of swap slot free notifications */
+	atomic64_t same_pages;		/* no. of same element filled pages */
+	atomic64_t huge_pages;		/* no. of huge pages */
+	atomic64_t pages_stored;	/* no. of pages currently stored */
+	atomic_long_t max_used_pages;	/* no. of maximum pages stored */
+	atomic64_t writestall;		/* no. of write slow paths */
+	atomic64_t miss_free;		/* no. of missed free */
+};
+
+struct zram {
+	struct zram_table_entry *table;
+	struct zs_pool *mem_pool;
+	struct zcomp *comp;
+	struct gendisk *disk;
+	/* Prevent concurrent execution of device init */
+	struct rw_semaphore init_lock;
+	/*
+	 * the number of pages zram can consume for storing compressed data
+	 */
+	unsigned long limit_pages;
+
+	struct zram_stats stats;
+	/*
+	 * This is the limit on amount of *uncompressed* worth of data
+	 * we can store in a disk.
+	 */
+	u64 disksize;	/* bytes */
+	char compressor[CRYPTO_MAX_ALG_NAME];
+	/*
+	 * zram is claimed so open request will be failed
+	 */
+	bool claim; /* Protected by bdev->bd_mutex */
+#ifdef CONFIG_ZRAM_WRITEBACK
+	struct file *backing_dev;
+	struct block_device *bdev;
+	unsigned int old_block_size;
+	unsigned long *bitmap;
+	unsigned long nr_pages;
+#endif
+#ifdef CONFIG_ZRAM_MEMORY_TRACKING
+	struct dentry *debugfs_dir;
+#endif
+};
+#endif