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Subject[RFC virtio-next 1/4] virtio: Move definitions to header file vring.h
Date
From: Sjur Brændeland <sjur.brandeland@stericsson.com>

Move the vring_virtqueue structure, memory barrier and debug
macros out from virtio_ring.c to the new header file vring.h.
This is done in order to allow other kernel modules to access the
virtio internal data-structures.

Signed-off-by: Sjur Brændeland <sjur.brandeland@stericsson.com>
---
Tis patch triggers a couple of checkpatch warnings, but I've
chosen to do a clean copy and not do any corrections.

drivers/virtio/virtio_ring.c | 96 +--------------------------------
drivers/virtio/vring.h | 121 ++++++++++++++++++++++++++++++++++++++++++
2 files changed, 122 insertions(+), 95 deletions(-)
create mode 100644 drivers/virtio/vring.h

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index ffd7e7d..9027af6 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -23,101 +23,7 @@
#include <linux/slab.h>
#include <linux/module.h>
#include <linux/hrtimer.h>
-
-/* virtio guest is communicating with a virtual "device" that actually runs on
- * a host processor. Memory barriers are used to control SMP effects. */
-#ifdef CONFIG_SMP
-/* Where possible, use SMP barriers which are more lightweight than mandatory
- * barriers, because mandatory barriers control MMIO effects on accesses
- * through relaxed memory I/O windows (which virtio-pci does not use). */
-#define virtio_mb(vq) \
- do { if ((vq)->weak_barriers) smp_mb(); else mb(); } while(0)
-#define virtio_rmb(vq) \
- do { if ((vq)->weak_barriers) smp_rmb(); else rmb(); } while(0)
-#define virtio_wmb(vq) \
- do { if ((vq)->weak_barriers) smp_wmb(); else wmb(); } while(0)
-#else
-/* We must force memory ordering even if guest is UP since host could be
- * running on another CPU, but SMP barriers are defined to barrier() in that
- * configuration. So fall back to mandatory barriers instead. */
-#define virtio_mb(vq) mb()
-#define virtio_rmb(vq) rmb()
-#define virtio_wmb(vq) wmb()
-#endif
-
-#ifdef DEBUG
-/* For development, we want to crash whenever the ring is screwed. */
-#define BAD_RING(_vq, fmt, args...) \
- do { \
- dev_err(&(_vq)->vq.vdev->dev, \
- "%s:"fmt, (_vq)->vq.name, ##args); \
- BUG(); \
- } while (0)
-/* Caller is supposed to guarantee no reentry. */
-#define START_USE(_vq) \
- do { \
- if ((_vq)->in_use) \
- panic("%s:in_use = %i\n", \
- (_vq)->vq.name, (_vq)->in_use); \
- (_vq)->in_use = __LINE__; \
- } while (0)
-#define END_USE(_vq) \
- do { BUG_ON(!(_vq)->in_use); (_vq)->in_use = 0; } while(0)
-#else
-#define BAD_RING(_vq, fmt, args...) \
- do { \
- dev_err(&_vq->vq.vdev->dev, \
- "%s:"fmt, (_vq)->vq.name, ##args); \
- (_vq)->broken = true; \
- } while (0)
-#define START_USE(vq)
-#define END_USE(vq)
-#endif
-
-struct vring_virtqueue
-{
- struct virtqueue vq;
-
- /* Actual memory layout for this queue */
- struct vring vring;
-
- /* Can we use weak barriers? */
- bool weak_barriers;
-
- /* Other side has made a mess, don't try any more. */
- bool broken;
-
- /* Host supports indirect buffers */
- bool indirect;
-
- /* Host publishes avail event idx */
- bool event;
-
- /* Head of free buffer list. */
- unsigned int free_head;
- /* Number we've added since last sync. */
- unsigned int num_added;
-
- /* Last used index we've seen. */
- u16 last_used_idx;
-
- /* How to notify other side. FIXME: commonalize hcalls! */
- void (*notify)(struct virtqueue *vq);
-
-#ifdef DEBUG
- /* They're supposed to lock for us. */
- unsigned int in_use;
-
- /* Figure out if their kicks are too delayed. */
- bool last_add_time_valid;
- ktime_t last_add_time;
-#endif
-
- /* Tokens for callbacks. */
- void *data[];
-};
-
-#define to_vvq(_vq) container_of(_vq, struct vring_virtqueue, vq)
+#include "vring.h"

/* Set up an indirect table of descriptors and add it to the queue. */
static int vring_add_indirect(struct vring_virtqueue *vq,
diff --git a/drivers/virtio/vring.h b/drivers/virtio/vring.h
new file mode 100644
index 0000000..b997fc3
--- /dev/null
+++ b/drivers/virtio/vring.h
@@ -0,0 +1,121 @@
+/* Virtio ring implementation.
+ *
+ * Copyright 2007 Rusty Russell IBM Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+#ifndef _LINUX_VIRTIO_RING_H_
+#define _LINUX_VIRTIO_RING_H_
+
+#include <linux/virtio_ring.h>
+#include <linux/virtio.h>
+
+struct vring_virtqueue
+{
+ struct virtqueue vq;
+
+ /* Actual memory layout for this queue */
+ struct vring vring;
+
+ /* Can we use weak barriers? */
+ bool weak_barriers;
+
+ /* Other side has made a mess, don't try any more. */
+ bool broken;
+
+ /* Host supports indirect buffers */
+ bool indirect;
+
+ /* Host publishes avail event idx */
+ bool event;
+
+ /* Number of free buffers */
+ unsigned int num_free;
+ /* Head of free buffer list. */
+ unsigned int free_head;
+ /* Number we've added since last sync. */
+ unsigned int num_added;
+
+ /* Last used index we've seen. */
+ u16 last_used_idx;
+
+ /* How to notify other side. FIXME: commonalize hcalls! */
+ void (*notify)(struct virtqueue *vq);
+
+#ifdef DEBUG
+ /* They're supposed to lock for us. */
+ unsigned int in_use;
+
+ /* Figure out if their kicks are too delayed. */
+ bool last_add_time_valid;
+ ktime_t last_add_time;
+#endif
+
+ /* Tokens for callbacks. */
+ void *data[];
+};
+#define to_vvq(_vq) container_of(_vq, struct vring_virtqueue, vq)
+
+/* virtio guest is communicating with a virtual "device" that actually runs on
+ * a host processor. Memory barriers are used to control SMP effects. */
+#ifdef CONFIG_SMP
+/* Where possible, use SMP barriers which are more lightweight than mandatory
+ * barriers, because mandatory barriers control MMIO effects on accesses
+ * through relaxed memory I/O windows (which virtio-pci does not use). */
+#define virtio_mb(vq) \
+ do { if ((vq)->weak_barriers) smp_mb(); else mb(); } while(0)
+#define virtio_rmb(vq) \
+ do { if ((vq)->weak_barriers) smp_rmb(); else rmb(); } while(0)
+#define virtio_wmb(vq) \
+ do { if ((vq)->weak_barriers) smp_wmb(); else wmb(); } while(0)
+#else
+/* We must force memory ordering even if guest is UP since host could be
+ * running on another CPU, but SMP barriers are defined to barrier() in that
+ * configuration. So fall back to mandatory barriers instead. */
+#define virtio_mb(vq) mb()
+#define virtio_rmb(vq) rmb()
+#define virtio_wmb(vq) wmb()
+#endif
+
+#ifdef DEBUG
+/* For development, we want to crash whenever the ring is screwed. */
+#define BAD_RING(_vq, fmt, args...) \
+ do { \
+ dev_err(&(_vq)->vq.vdev->dev, \
+ "%s:"fmt, (_vq)->vq.name, ##args); \
+ BUG(); \
+ } while (0)
+/* Caller is supposed to guarantee no reentry. */
+#define START_USE(_vq) \
+ do { \
+ if ((_vq)->in_use) \
+ panic("%s:in_use = %i\n", \
+ (_vq)->vq.name, (_vq)->in_use); \
+ (_vq)->in_use = __LINE__; \
+ } while (0)
+#define END_USE(_vq) \
+ do { BUG_ON(!(_vq)->in_use); (_vq)->in_use = 0; } while(0)
+#else
+#define BAD_RING(_vq, fmt, args...) \
+ do { \
+ dev_err(&_vq->vq.vdev->dev, \
+ "%s:"fmt, (_vq)->vq.name, ##args); \
+ (_vq)->broken = true; \
+ } while (0)
+#define START_USE(vq)
+#define END_USE(vq)
+#endif
+
+#endif
--
1.7.9.5
--
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