Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / include / linux / dm-io.h

diff --git a/kernel/include/linux/dm-io.h b/kernel/include/linux/dm-io.h
new file mode 100644 (file)
index 0000000..a68cbe5
--- /dev/null
+++ b/kernel/include/linux/dm-io.h
@@ -0,0 +1,84 @@
+/*
+ * Copyright (C) 2003 Sistina Software
+ * Copyright (C) 2004 - 2008 Red Hat, Inc. All rights reserved.
+ *
+ * Device-Mapper low-level I/O.
+ *
+ * This file is released under the GPL.
+ */
+
+#ifndef _LINUX_DM_IO_H
+#define _LINUX_DM_IO_H
+
+#ifdef __KERNEL__
+
+#include <linux/types.h>
+
+struct dm_io_region {
+       struct block_device *bdev;
+       sector_t sector;
+       sector_t count;         /* If this is zero the region is ignored. */
+};
+
+struct page_list {
+       struct page_list *next;
+       struct page *page;
+};
+
+typedef void (*io_notify_fn)(unsigned long error, void *context);
+
+enum dm_io_mem_type {
+       DM_IO_PAGE_LIST,/* Page list */
+       DM_IO_BIO,      /* Bio vector */
+       DM_IO_VMA,      /* Virtual memory area */
+       DM_IO_KMEM,     /* Kernel memory */
+};
+
+struct dm_io_memory {
+       enum dm_io_mem_type type;
+
+       unsigned offset;
+
+       union {
+               struct page_list *pl;
+               struct bio *bio;
+               void *vma;
+               void *addr;
+       } ptr;
+};
+
+struct dm_io_notify {
+       io_notify_fn fn;        /* Callback for asynchronous requests */
+       void *context;          /* Passed to callback */
+};
+
+/*
+ * IO request structure
+ */
+struct dm_io_client;
+struct dm_io_request {
+       int bi_rw;                      /* READ|WRITE - not READA */
+       struct dm_io_memory mem;        /* Memory to use for io */
+       struct dm_io_notify notify;     /* Synchronous if notify.fn is NULL */
+       struct dm_io_client *client;    /* Client memory handler */
+};
+
+/*
+ * For async io calls, users can alternatively use the dm_io() function below
+ * and dm_io_client_create() to create private mempools for the client.
+ *
+ * Create/destroy may block.
+ */
+struct dm_io_client *dm_io_client_create(void);
+void dm_io_client_destroy(struct dm_io_client *client);
+
+/*
+ * IO interface using private per-client pools.
+ * Each bit in the optional 'sync_error_bits' bitset indicates whether an
+ * error occurred doing io to the corresponding region.
+ */
+int dm_io(struct dm_io_request *io_req, unsigned num_regions,
+         struct dm_io_region *region, unsigned long *sync_error_bits);
+
+#endif /* __KERNEL__ */
+#endif /* _LINUX_DM_IO_H */