1 files changed, 70 insertions, 0 deletions
diff --git a/drivers/md/dm-pcache/cache_dev.h b/drivers/md/dm-pcache/cache_dev.h
new file mode 100644
index 000000000000..6251eb4ebe96
--- /dev/null
+++ b/drivers/md/dm-pcache/cache_dev.h
@@ -0,0 +1,70 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+#ifndef _PCACHE_CACHE_DEV_H
+#define _PCACHE_CACHE_DEV_H
+
+#include <linux/device.h>
+#include <linux/device-mapper.h>
+
+#include "pcache_internal.h"
+
+#define PCACHE_MAGIC				0x65B05EFA96C596EFULL
+
+#define PCACHE_SB_OFF				(4 * PCACHE_KB)
+#define PCACHE_SB_SIZE				(4 * PCACHE_KB)
+
+#define PCACHE_CACHE_INFO_OFF			(PCACHE_SB_OFF + PCACHE_SB_SIZE)
+#define PCACHE_CACHE_INFO_SIZE			(4 * PCACHE_KB)
+
+#define PCACHE_CACHE_CTRL_OFF			(PCACHE_CACHE_INFO_OFF + (PCACHE_CACHE_INFO_SIZE * PCACHE_META_INDEX_MAX))
+#define PCACHE_CACHE_CTRL_SIZE			(4 * PCACHE_KB)
+
+#define PCACHE_SEGMENTS_OFF			(PCACHE_CACHE_CTRL_OFF + PCACHE_CACHE_CTRL_SIZE)
+#define PCACHE_SEG_INFO_SIZE			(4 * PCACHE_KB)
+
+#define PCACHE_CACHE_DEV_SIZE_MIN		(512 * PCACHE_MB)	/* 512 MB */
+#define PCACHE_SEG_SIZE				(16 * PCACHE_MB)	/* Size of each PCACHE segment (16 MB) */
+
+#define CACHE_DEV_SB(cache_dev)			((struct pcache_sb *)(cache_dev->mapping + PCACHE_SB_OFF))
+#define CACHE_DEV_CACHE_INFO(cache_dev)		((void *)cache_dev->mapping + PCACHE_CACHE_INFO_OFF)
+#define CACHE_DEV_CACHE_CTRL(cache_dev)		((void *)cache_dev->mapping + PCACHE_CACHE_CTRL_OFF)
+#define CACHE_DEV_SEGMENTS(cache_dev)		((void *)cache_dev->mapping + PCACHE_SEGMENTS_OFF)
+#define CACHE_DEV_SEGMENT(cache_dev, id)	((void *)CACHE_DEV_SEGMENTS(cache_dev) + (u64)id * PCACHE_SEG_SIZE)
+
+/*
+ * PCACHE SB flags configured during formatting
+ *
+ * The PCACHE_SB_F_xxx flags define registration requirements based on cache_dev
+ * formatting. For a machine to register a cache_dev:
+ * - PCACHE_SB_F_BIGENDIAN: Requires a big-endian machine.
+ */
+#define PCACHE_SB_F_BIGENDIAN			BIT(0)
+
+struct pcache_sb {
+	__le32 crc;
+	__le32 flags;
+	__le64 magic;
+
+	__le32 seg_num;
+};
+
+struct pcache_cache_dev {
+	u32				sb_flags;
+	u32				seg_num;
+	void				*mapping;
+	bool				use_vmap;
+
+	struct dm_dev			*dm_dev;
+
+	struct mutex			seg_lock;
+	unsigned long			*seg_bitmap;
+};
+
+struct dm_pcache;
+int cache_dev_start(struct dm_pcache *pcache);
+void cache_dev_stop(struct dm_pcache *pcache);
+
+void cache_dev_zero_range(struct pcache_cache_dev *cache_dev, void *pos, u32 size);
+
+int cache_dev_get_empty_segment_id(struct pcache_cache_dev *cache_dev, u32 *seg_id);
+
+#endif /* _PCACHE_CACHE_DEV_H */