xen: add blkback support
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Conflicts:
drivers/xen/Makefile
diff --git a/drivers/xen/blkback/common.h b/drivers/xen/blkback/common.h
new file mode 100644
index 0000000..422e935
--- /dev/null
+++ b/drivers/xen/blkback/common.h
@@ -0,0 +1,139 @@
+/*
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License version 2
+ * as published by the Free Software Foundation; or, when distributed
+ * separately from the Linux kernel or incorporated into other
+ * software packages, subject to the following license:
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this source file (the "Software"), to deal in the Software without
+ * restriction, including without limitation the rights to use, copy, modify,
+ * merge, publish, distribute, sublicense, and/or sell copies of the Software,
+ * and to permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#ifndef __BLKIF__BACKEND__COMMON_H__
+#define __BLKIF__BACKEND__COMMON_H__
+
+#include <linux/version.h>
+#include <linux/module.h>
+#include <linux/interrupt.h>
+#include <linux/slab.h>
+#include <linux/blkdev.h>
+#include <linux/vmalloc.h>
+#include <linux/wait.h>
+#include <asm/io.h>
+#include <asm/setup.h>
+#include <asm/pgalloc.h>
+#include <xen/evtchn.h>
+#include <asm/hypervisor.h>
+#include <xen/blkif.h>
+#include <xen/gnttab.h>
+#include <xen/driver_util.h>
+#include <xen/xenbus.h>
+
+#define DPRINTK(_f, _a...) \
+ pr_debug("(file=%s, line=%d) " _f, \
+ __FILE__ , __LINE__ , ## _a )
+
+struct vbd {
+ blkif_vdev_t handle; /* what the domain refers to this vbd as */
+ unsigned char readonly; /* Non-zero -> read-only */
+ unsigned char type; /* VDISK_xxx */
+ u32 pdevice; /* phys device that this vbd maps to */
+ struct block_device *bdev;
+};
+
+struct backend_info;
+
+typedef struct blkif_st {
+ /* Unique identifier for this interface. */
+ domid_t domid;
+ unsigned int handle;
+ /* Physical parameters of the comms window. */
+ unsigned int irq;
+ /* Comms information. */
+ enum blkif_protocol blk_protocol;
+ blkif_back_rings_t blk_rings;
+ struct vm_struct *blk_ring_area;
+ /* The VBD attached to this interface. */
+ struct vbd vbd;
+ /* Back pointer to the backend_info. */
+ struct backend_info *be;
+ /* Private fields. */
+ spinlock_t blk_ring_lock;
+ atomic_t refcnt;
+
+ wait_queue_head_t wq;
+ struct task_struct *xenblkd;
+ unsigned int waiting_reqs;
+ request_queue_t *plug;
+
+ /* statistics */
+ unsigned long st_print;
+ int st_rd_req;
+ int st_wr_req;
+ int st_oo_req;
+ int st_br_req;
+ int st_rd_sect;
+ int st_wr_sect;
+
+ wait_queue_head_t waiting_to_free;
+
+ grant_handle_t shmem_handle;
+ grant_ref_t shmem_ref;
+} blkif_t;
+
+blkif_t *blkif_alloc(domid_t domid);
+void blkif_disconnect(blkif_t *blkif);
+void blkif_free(blkif_t *blkif);
+int blkif_map(blkif_t *blkif, unsigned long shared_page, unsigned int evtchn);
+
+#define blkif_get(_b) (atomic_inc(&(_b)->refcnt))
+#define blkif_put(_b) \
+ do { \
+ if (atomic_dec_and_test(&(_b)->refcnt)) \
+ wake_up(&(_b)->waiting_to_free);\
+ } while (0)
+
+/* Create a vbd. */
+int vbd_create(blkif_t *blkif, blkif_vdev_t vdevice, unsigned major,
+ unsigned minor, int readonly, int cdrom);
+void vbd_free(struct vbd *vbd);
+
+unsigned long long vbd_size(struct vbd *vbd);
+unsigned int vbd_info(struct vbd *vbd);
+unsigned long vbd_secsize(struct vbd *vbd);
+
+struct phys_req {
+ unsigned short dev;
+ unsigned short nr_sects;
+ struct block_device *bdev;
+ blkif_sector_t sector_number;
+};
+
+int vbd_translate(struct phys_req *req, blkif_t *blkif, int operation);
+
+void blkif_interface_init(void);
+
+void blkif_xenbus_init(void);
+
+irqreturn_t blkif_be_int(int irq, void *dev_id, struct pt_regs *regs);
+int blkif_schedule(void *arg);
+
+int blkback_barrier(struct xenbus_transaction xbt,
+ struct backend_info *be, int state);
+
+#endif /* __BLKIF__BACKEND__COMMON_H__ */