[RFC PATCH v3 07/17] ioq: add vbus helpers

Gregory Haskins
2009-04-21T18:39:48Z

It will be common to map an IOQ over the VBUS shared-memory interfaces,
so lets generalize their setup so we can reuse the pattern.

Signed-off-by: Gregory Haskins <ghaskins@novell.com>
---

include/linux/vbus_device.h | 7 +++
include/linux/vbus_driver.h | 7 +++
kernel/vbus/Kconfig | 2 +
kernel/vbus/Makefile | 1
kernel/vbus/proxy.c | 64 +++++++++++++++++++++++++++++++
kernel/vbus/shm-ioq.c | 89 +++++++++++++++++++++++++++++++++++++++++++
6 files changed, 170 insertions(+), 0 deletions(-)
create mode 100644 kernel/vbus/shm-ioq.c

diff --git a/include/linux/vbus_device.h b/include/linux/vbus_device.h
index f73cd86..c91bce4 100644
--- a/include/linux/vbus_device.h
+++ b/include/linux/vbus_device.h
@@ -102,6 +102,7 @@
#include <linux/configfs.h>
#include <linux/rbtree.h>
#include <linux/shm_signal.h>
+#include <linux/ioq.h>
#include <linux/vbus.h>
#include <asm/atomic.h>

@@ -414,4 +415,10 @@ static inline void vbus_connection_put(struct vbus_connection *conn)
conn->ops->release(conn);
}

+/*
+ * device-side IOQ helper - dereferences device-shm as an IOQ
+ */
+int vbus_shm_ioq_attach(struct vbus_shm *shm, struct shm_signal *signal,
+ int maxcount, struct ioq **ioq);
+
#endif /* _LINUX_VBUS_DEVICE_H */
diff --git a/include/linux/vbus_driver.h b/include/linux/vbus_driver.h
index c53e13f..9cfbf60 100644
--- a/include/linux/vbus_driver.h
+++ b/include/linux/vbus_driver.h
@@ -26,6 +26,7 @@

#include <linux/device.h>
#include <linux/shm_signal.h>
+#include <linux/ioq.h>

struct vbus_device_proxy;
struct vbus_driver;
@@ -70,4 +71,10 @@ struct vbus_driver {
int vbus_driver_register(struct vbus_driver *drv);
void vbus_driver_unregister(struct vbus_driver *drv);

+/*
+ * driver-side IOQ helper - allocates device-shm and maps an IOQ on it
+ */
+int vbus_driver_ioq_alloc(struct vbus_device_proxy *dev, int id, int prio,
+ size_t ringsize, struct ioq **ioq);
+
#endif /* _LINUX_VBUS_DRIVER_H */
diff --git a/kernel/vbus/Kconfig b/kernel/vbus/Kconfig
index 3aaa085..71acd6f 100644
--- a/kernel/vbus/Kconfig
+++ b/kernel/vbus/Kconfig
@@ -6,6 +6,7 @@ config VBUS
bool "Virtual Bus"
select CONFIGFS_FS
select SHM_SIGNAL
+ select IOQ
default n
help
Provides a mechansism for declaring virtual-bus objects and binding
@@ -15,6 +16,7 @@ config VBUS

config VBUS_DRIVERS
tristate "VBUS Driver support"
+ select IOQ
default n
help
Adds support for a virtual bus model for proxying drivers.
diff --git a/kernel/vbus/Makefile b/kernel/vbus/Makefile
index d028ece..45f6503 100644
--- a/kernel/vbus/Makefile
+++ b/kernel/vbus/Makefile
@@ -1,4 +1,5 @@
obj-$(CONFIG_VBUS) += core.o devclass.o config.o attribute.o map.o client.o
+obj-$(CONFIG_VBUS) += shm-ioq.o

vbus-proxy-objs += proxy.o
obj-$(CONFIG_VBUS_DRIVERS) += vbus-proxy.o
diff --git a/kernel/vbus/proxy.c b/kernel/vbus/proxy.c
index 3177f9f..88cd904 100644
--- a/kernel/vbus/proxy.c
+++ b/kernel/vbus/proxy.c
@@ -150,3 +150,67 @@ void vbus_driver_unregister(struct vbus_driver *drv)
}
EXPORT_SYMBOL_GPL(vbus_driver_unregister);

+/*
+ *---------------------------------
+ * driver-side IOQ helper
+ *---------------------------------
+ */
+static void
+vbus_driver_ioq_release(struct ioq *ioq)
+{
+ kfree(ioq->head_desc);
+ kfree(ioq);
+}
+
+static struct ioq_ops vbus_driver_ioq_ops = {
+ .release = vbus_driver_ioq_release,
+};
+
+
+int vbus_driver_ioq_alloc(struct vbus_device_proxy *dev, int id, int prio,
+ size_t count, struct ioq **ioq)
+{
+ struct ioq *_ioq;
+ struct ioq_ring_head *head = NULL;
+ struct shm_signal *signal = NULL;
+ size_t len = IOQ_HEAD_DESC_SIZE(count);
+ int ret = -ENOMEM;
+
+ _ioq = kzalloc(sizeof(*_ioq), GFP_KERNEL);
+ if (!_ioq)
+ goto error;
+
+ head = kzalloc(len, GFP_KERNEL | GFP_DMA);
+ if (!head)
+ goto error;
+
+ head->magic = IOQ_RING_MAGIC;
+ head->ver = IOQ_RING_VER;
+ head->count = count;
+
+ ret = dev->ops->shm(dev, id, prio, head, len,
+ &head->signal, &signal, 0);
+ if (ret < 0)
+ goto error;
+
+ ioq_init(_ioq,
+ &vbus_driver_ioq_ops,
+ ioq_locality_north,
+ head,
+ signal,
+ count);
+
+ *ioq = _ioq;
+
+ return 0;
+
+ error:
+ kfree(_ioq);
+ kfree(head);
+
+ if (signal)
+ shm_signal_put(signal);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(vbus_driver_ioq_alloc);
diff --git a/kernel/vbus/shm-ioq.c b/kernel/vbus/shm-ioq.c
new file mode 100644
index 0000000..a627337
--- /dev/null
+++ b/kernel/vbus/shm-ioq.c
@@ -0,0 +1,89 @@
+/*
+ * Copyright 2009 Novell. All Rights Reserved.
+ *
+ * IOQ helper for devices - This module implements an IOQ which has
+ * been shared with a device via a vbus_shm segment.
+ *
+ * Author:
+ * Gregory Haskins <ghaskins@novell.com>
+ *
+ * This file is free software; you can redistribute it and/or modify
+ * it under the terms of version 2 of the GNU General Public License
+ * as published by the Free Software Foundation.
+ *
+ * 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.
+ */
+
+#include <linux/ioq.h>
+#include <linux/vbus_device.h>
+
+struct _ioq {
+ struct vbus_shm *shm;
+ struct ioq ioq;
+};
+
+static void
+_shm_ioq_release(struct ioq *ioq)
+{
+ struct _ioq *_ioq = container_of(ioq, struct _ioq, ioq);
+
+ /* the signal is released by the IOQ infrastructure */
+ vbus_shm_put(_ioq->shm);
+ kfree(_ioq);
+}
+
+static struct ioq_ops _shm_ioq_ops = {
+ .release = _shm_ioq_release,
+};
+
+int vbus_shm_ioq_attach(struct vbus_shm *shm, struct shm_signal *signal,
+ int maxcount, struct ioq **ioq)
+{
+ struct _ioq *_ioq;
+ struct ioq_ring_head *head = NULL;
+ size_t ringcount;
+
+ if (!signal)
+ return -EINVAL;
+
+ _ioq = kzalloc(sizeof(*_ioq), GFP_KERNEL);
+ if (!_ioq)
+ return -ENOMEM;
+
+ head = (struct ioq_ring_head *)shm->ptr;
+
+ if (head->magic != IOQ_RING_MAGIC)
+ return -EINVAL;
+
+ if (head->ver != IOQ_RING_VER)
+ return -EINVAL;
+
+ ringcount = head->count;
+
+ if ((maxcount != -1) && (ringcount > maxcount))
+ return -EINVAL;
+
+ /*
+ * Sanity check the ringcount against the actual length of the segment
+ */
+ if (IOQ_HEAD_DESC_SIZE(ringcount) != shm->len)
+ return -EINVAL;
+
+ _ioq->shm = shm;
+
+ ioq_init(&_ioq->ioq, &_shm_ioq_ops, ioq_locality_south, head,
+ signal, ringcount);
+
+ *ioq = &_ioq->ioq;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(vbus_shm_ioq_attach);
+