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-rw-r--r--drivers/block/xen-blkback/common.h233
1 files changed, 233 insertions, 0 deletions
diff --git a/drivers/block/xen-blkback/common.h b/drivers/block/xen-blkback/common.h
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index 00000000000..9e40b283a46
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+++ b/drivers/block/xen-blkback/common.h
@@ -0,0 +1,233 @@
+/*
+ * 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 __XEN_BLKIF__BACKEND__COMMON_H__
+#define __XEN_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 <linux/io.h>
+#include <asm/setup.h>
+#include <asm/pgalloc.h>
+#include <asm/hypervisor.h>
+#include <xen/grant_table.h>
+#include <xen/xenbus.h>
+#include <xen/interface/io/ring.h>
+#include <xen/interface/io/blkif.h>
+#include <xen/interface/io/protocols.h>
+
+#define DRV_PFX "xen-blkback:"
+#define DPRINTK(fmt, args...) \
+ pr_debug(DRV_PFX "(%s:%d) " fmt ".\n", \
+ __func__, __LINE__, ##args)
+
+
+/* Not a real protocol. Used to generate ring structs which contain
+ * the elements common to all protocols only. This way we get a
+ * compiler-checkable way to use common struct elements, so we can
+ * avoid using switch(protocol) in a number of places. */
+struct blkif_common_request {
+ char dummy;
+};
+struct blkif_common_response {
+ char dummy;
+};
+
+/* i386 protocol version */
+#pragma pack(push, 4)
+struct blkif_x86_32_request {
+ uint8_t operation; /* BLKIF_OP_??? */
+ uint8_t nr_segments; /* number of segments */
+ blkif_vdev_t handle; /* only for read/write requests */
+ uint64_t id; /* private guest value, echoed in resp */
+ blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */
+ struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
+};
+struct blkif_x86_32_response {
+ uint64_t id; /* copied from request */
+ uint8_t operation; /* copied from request */
+ int16_t status; /* BLKIF_RSP_??? */
+};
+#pragma pack(pop)
+
+/* x86_64 protocol version */
+struct blkif_x86_64_request {
+ uint8_t operation; /* BLKIF_OP_??? */
+ uint8_t nr_segments; /* number of segments */
+ blkif_vdev_t handle; /* only for read/write requests */
+ uint64_t __attribute__((__aligned__(8))) id;
+ blkif_sector_t sector_number;/* start sector idx on disk (r/w only) */
+ struct blkif_request_segment seg[BLKIF_MAX_SEGMENTS_PER_REQUEST];
+};
+struct blkif_x86_64_response {
+ uint64_t __attribute__((__aligned__(8))) id;
+ uint8_t operation; /* copied from request */
+ int16_t status; /* BLKIF_RSP_??? */
+};
+
+DEFINE_RING_TYPES(blkif_common, struct blkif_common_request,
+ struct blkif_common_response);
+DEFINE_RING_TYPES(blkif_x86_32, struct blkif_x86_32_request,
+ struct blkif_x86_32_response);
+DEFINE_RING_TYPES(blkif_x86_64, struct blkif_x86_64_request,
+ struct blkif_x86_64_response);
+
+union blkif_back_rings {
+ struct blkif_back_ring native;
+ struct blkif_common_back_ring common;
+ struct blkif_x86_32_back_ring x86_32;
+ struct blkif_x86_64_back_ring x86_64;
+};
+
+enum blkif_protocol {
+ BLKIF_PROTOCOL_NATIVE = 1,
+ BLKIF_PROTOCOL_X86_32 = 2,
+ BLKIF_PROTOCOL_X86_64 = 3,
+};
+
+struct xen_vbd {
+ /* What the domain refers to this vbd as. */
+ blkif_vdev_t handle;
+ /* Non-zero -> read-only */
+ unsigned char readonly;
+ /* VDISK_xxx */
+ unsigned char type;
+ /* phys device that this vbd maps to. */
+ u32 pdevice;
+ struct block_device *bdev;
+ /* Cached size parameter. */
+ sector_t size;
+ bool flush_support;
+};
+
+struct backend_info;
+
+struct xen_blkif {
+ /* 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;
+ union blkif_back_rings blk_rings;
+ struct vm_struct *blk_ring_area;
+ /* The VBD attached to this interface. */
+ struct xen_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;
+ /* One thread per one blkif. */
+ struct task_struct *xenblkd;
+ unsigned int waiting_reqs;
+
+ /* statistics */
+ unsigned long st_print;
+ int st_rd_req;
+ int st_wr_req;
+ int st_oo_req;
+ int st_f_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;
+};
+
+
+#define vbd_sz(_v) ((_v)->bdev->bd_part ? \
+ (_v)->bdev->bd_part->nr_sects : \
+ get_capacity((_v)->bdev->bd_disk))
+
+#define xen_blkif_get(_b) (atomic_inc(&(_b)->refcnt))
+#define xen_blkif_put(_b) \
+ do { \
+ if (atomic_dec_and_test(&(_b)->refcnt)) \
+ wake_up(&(_b)->waiting_to_free);\
+ } while (0)
+
+struct phys_req {
+ unsigned short dev;
+ unsigned short nr_sects;
+ struct block_device *bdev;
+ blkif_sector_t sector_number;
+};
+int xen_blkif_interface_init(void);
+
+int xen_blkif_xenbus_init(void);
+
+irqreturn_t xen_blkif_be_int(int irq, void *dev_id);
+int xen_blkif_schedule(void *arg);
+
+int xen_blkbk_flush_diskcache(struct xenbus_transaction xbt,
+ struct backend_info *be, int state);
+
+struct xenbus_device *xen_blkbk_xenbus(struct backend_info *be);
+
+static inline void blkif_get_x86_32_req(struct blkif_request *dst,
+ struct blkif_x86_32_request *src)
+{
+ int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST;
+ dst->operation = src->operation;
+ dst->nr_segments = src->nr_segments;
+ dst->handle = src->handle;
+ dst->id = src->id;
+ dst->u.rw.sector_number = src->sector_number;
+ barrier();
+ if (n > dst->nr_segments)
+ n = dst->nr_segments;
+ for (i = 0; i < n; i++)
+ dst->u.rw.seg[i] = src->seg[i];
+}
+
+static inline void blkif_get_x86_64_req(struct blkif_request *dst,
+ struct blkif_x86_64_request *src)
+{
+ int i, n = BLKIF_MAX_SEGMENTS_PER_REQUEST;
+ dst->operation = src->operation;
+ dst->nr_segments = src->nr_segments;
+ dst->handle = src->handle;
+ dst->id = src->id;
+ dst->u.rw.sector_number = src->sector_number;
+ barrier();
+ if (n > dst->nr_segments)
+ n = dst->nr_segments;
+ for (i = 0; i < n; i++)
+ dst->u.rw.seg[i] = src->seg[i];
+}
+
+#endif /* __XEN_BLKIF__BACKEND__COMMON_H__ */
generated by cgit v1.2.3-70-g09d2 (git 2.46.0) at 2024-11-14 20:57:00 +0000