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Message-ID: <tkrat.f364570373ba8da5@s5r6.in-berlin.de>
Date: Sun, 4 Jan 2009 16:27:31 +0100 (CET)
From: Stefan Richter <stefanr@...6.in-berlin.de>
To: linux1394-devel@...ts.sourceforge.net
cc: linux-kernel@...r.kernel.org
Subject: [PATCH 06/11] firewire: cdev: add ioctls for manual iso resource
management
This adds ioctls for allocation and deallocation of a channel or/and
bandwidth without auto-reallocation and without auto-deallocation.
The benefit of these ioctls is that libraw1394-style isochronous
resource management can be implemented without write access to the IRM's
character device file.
Signed-off-by: Stefan Richter <stefanr@...6.in-berlin.de>
---
drivers/firewire/fw-cdev.c | 67 +++++++++++++++++++++++++++-------
include/linux/firewire-cdev.h | 38 +++++++++++++++----
2 files changed, 84 insertions(+), 21 deletions(-)
Index: linux/include/linux/firewire-cdev.h
===================================================================
--- linux.orig/include/linux/firewire-cdev.h
+++ linux/include/linux/firewire-cdev.h
@@ -151,7 +151,7 @@ struct fw_cdev_event_iso_interrupt {
/**
* struct fw_cdev_event_iso_resource - Iso resources were allocated or freed
* @closure: See &fw_cdev_event_common;
- * set by %FW_CDEV_IOC_ALLOCATE_ISO_RESOURCE ioctl
+ * set by %FW_CDEV_IOC_(DE)ALLOCATE_ISO_RESOURCE(_ONCE) ioctl
* @type: %FW_CDEV_EVENT_ISO_RESOURCE_ALLOCATED or
* %FW_CDEV_EVENT_ISO_RESOURCE_DEALLOCATED
* @handle: Reference by which an allocated resource can be deallocated
@@ -164,12 +164,12 @@ struct fw_cdev_event_iso_interrupt {
* resource was allocated at the IRM. The client has to check @channel and
* @bandwidth for whether the allocation actually succeeded.
*
- * @channel is <0 if no channel was allocated.
- * @bandwidth is 0 if no bandwidth was allocated.
- *
* An %FW_CDEV_EVENT_ISO_RESOURCE_DEALLOCATED event is sent after an isochronous
* resource was deallocated at the IRM. It is also sent when automatic
* reallocation after a bus reset failed.
+ *
+ * @channel is <0 if no channel was (de)allocated or if reallocation failed.
+ * @bandwidth is 0 if no bandwidth was (de)allocated or if reallocation failed.
*/
struct fw_cdev_event_iso_resource {
__u64 closure;
@@ -227,6 +227,8 @@ union fw_cdev_event {
/* available since kernel version 2.6.30 */
#define FW_CDEV_IOC_ALLOCATE_ISO_RESOURCE _IOWR('#', 0x0d, struct fw_cdev_allocate_iso_resource)
#define FW_CDEV_IOC_DEALLOCATE_ISO_RESOURCE _IOW('#', 0x0e, struct fw_cdev_deallocate)
+#define FW_CDEV_IOC_ALLOCATE_ISO_RESOURCE_ONCE _IOW('#', 0x0f, struct fw_cdev_allocate_iso_resource)
+#define FW_CDEV_IOC_DEALLOCATE_ISO_RESOURCE_ONCE _IOW('#', 0x10, struct fw_cdev_allocate_iso_resource)
/* FW_CDEV_VERSION History
*
@@ -523,11 +525,12 @@ struct fw_cdev_get_cycle_timer {
};
/**
- * struct fw_cdev_allocate_iso_resource - Allocate a channel or bandwidth
+ * struct fw_cdev_allocate_iso_resource - (De)allocate a channel or bandwidth
* @closure: Passed back to userspace in correponding iso resource events
- * @channels: Isochronous channels of which one is to be allocated
- * @bandwidth: Isochronous bandwidth units to be allocated
- * @handle: Handle to the allocation, written by the kernel
+ * @channels: Isochronous channels of which one is to be (de)allocated
+ * @bandwidth: Isochronous bandwidth units to be (de)allocated
+ * @handle: Handle to the allocation, written by the kernel (only valid in
+ * case of %FW_CDEV_IOC_ALLOCATE_ISO_RESOURCE ioctls)
*
* The %FW_CDEV_IOC_ALLOCATE_ISO_RESOURCE ioctl initiates allocation of an
* isochronous channel and/or of isochronous bandwidth at the isochronous
@@ -539,6 +542,25 @@ struct fw_cdev_get_cycle_timer {
* will be sent. The kernel will also automatically deallocate the resources
* when the file descriptor is closed.
*
+ * The %FW_CDEV_IOC_DEALLOCATE_ISO_RESOURCE ioctl can be used to initiate
+ * deallocation of resources which were allocated as described above.
+ * An %FW_CDEV_EVENT_ISO_RESOURCE_DEALLOCATED event concludes this operation.
+ *
+ * The %FW_CDEV_IOC_ALLOCATE_ISO_RESOURCE_ONCE ioctl is a variant of allocation
+ * without automatic re- or deallocation.
+ * An %FW_CDEV_EVENT_ISO_RESOURCE_ALLOCATED event concludes this operation,
+ * indicating success or failure in its data.
+ *
+ * The %FW_CDEV_IOC_DEALLOCATE_ISO_RESOURCE_ONCE ioctl works like
+ * %FW_CDEV_IOC_ALLOCATE_ISO_RESOURCE_ONCE except that resources are freed
+ * instead of allocated. At most one channel may be specified in this ioctl.
+ * An %FW_CDEV_EVENT_ISO_RESOURCE_DEALLOCATED event concludes this operation.
+ *
+ * To summarize, %FW_CDEV_IOC_DEALLOCATE_ISO_RESOURCE allocates iso resources
+ * for the lifetime of the fd or handle.
+ * In contrast, %FW_CDEV_IOC_ALLOCATE_ISO_RESOURCE_ONCE allocates iso resources
+ * for the duration of a bus generation.
+ *
* @channels is a host-endian bitfield with the most significant bit
* representing channel 0 and the least significant bit representing channel 63:
* 1ULL << (63 - c)
Index: linux/drivers/firewire/fw-cdev.c
===================================================================
--- linux.orig/drivers/firewire/fw-cdev.c
+++ linux/drivers/firewire/fw-cdev.c
@@ -121,14 +121,15 @@ struct iso_resource {
struct client *client;
/* Schedule work and access todo only with client->lock held. */
struct delayed_work work;
- enum {ISO_RES_ALLOC, ISO_RES_REALLOC, ISO_RES_DEALLOC,} todo;
+ enum {ISO_RES_ALLOC, ISO_RES_REALLOC, ISO_RES_DEALLOC,
+ ISO_RES_ALLOC_ONCE, ISO_RES_DEALLOC_ONCE,} todo;
int generation;
u64 channels;
s32 bandwidth;
struct iso_resource_event *e_alloc, *e_dealloc;
};
-static void schedule_iso_resource(struct iso_resource *);
+static int schedule_iso_resource(struct iso_resource *);
static void release_iso_resource(struct client *, struct client_resource *);
/*
@@ -1033,7 +1034,9 @@ static void iso_resource_work(struct wor
skip = todo == ISO_RES_REALLOC &&
r->generation == generation;
}
- free = todo == ISO_RES_DEALLOC;
+ free = todo == ISO_RES_DEALLOC ||
+ todo == ISO_RES_ALLOC_ONCE ||
+ todo == ISO_RES_DEALLOC_ONCE;
r->generation = generation;
spin_unlock_irq(&client->lock);
@@ -1044,7 +1047,9 @@ static void iso_resource_work(struct wor
fw_iso_resource_manage(client->device->card, generation,
r->channels, &channel, &bandwidth,
- todo == ISO_RES_ALLOC || todo == ISO_RES_REALLOC);
+ todo == ISO_RES_ALLOC ||
+ todo == ISO_RES_REALLOC ||
+ todo == ISO_RES_ALLOC_ONCE);
/*
* Is this generation outdated already? As long as this resource sticks
* in the idr, it will be scheduled again for a newer generation or at
@@ -1082,7 +1087,7 @@ static void iso_resource_work(struct wor
if (todo == ISO_RES_REALLOC && success)
goto out;
- if (todo == ISO_RES_ALLOC) {
+ if (todo == ISO_RES_ALLOC || todo == ISO_RES_ALLOC_ONCE) {
e = r->e_alloc;
r->e_alloc = NULL;
} else {
@@ -1106,10 +1111,17 @@ static void iso_resource_work(struct wor
client_put(client);
}
-static void schedule_iso_resource(struct iso_resource *r)
+static int schedule_iso_resource(struct iso_resource *r)
{
- if (schedule_delayed_work(&r->work, 0))
- client_get(r->client);
+ int scheduled;
+
+ client_get(r->client);
+
+ scheduled = schedule_delayed_work(&r->work, 0);
+ if (!scheduled)
+ client_put(r->client);
+
+ return scheduled;
}
static void release_iso_resource(struct client *client,
@@ -1124,9 +1136,9 @@ static void release_iso_resource(struct
spin_unlock_irq(&client->lock);
}
-static int ioctl_allocate_iso_resource(struct client *client, void *buffer)
+static int init_iso_resource(struct client *client,
+ struct fw_cdev_allocate_iso_resource *request, int todo)
{
- struct fw_cdev_allocate_iso_resource *request = buffer;
struct iso_resource_event *e1, *e2;
struct iso_resource *r;
int ret;
@@ -1146,7 +1158,7 @@ static int ioctl_allocate_iso_resource(s
INIT_DELAYED_WORK(&r->work, iso_resource_work);
r->client = client;
- r->todo = ISO_RES_ALLOC;
+ r->todo = todo;
r->generation = -1;
r->channels = request->channels;
r->bandwidth = request->bandwidth;
@@ -1158,8 +1170,14 @@ static int ioctl_allocate_iso_resource(s
e2->resource.closure = request->closure;
e2->resource.type = FW_CDEV_EVENT_ISO_RESOURCE_DEALLOCATED;
- r->resource.release = release_iso_resource;
- ret = add_client_resource(client, &r->resource, GFP_KERNEL);
+ if (todo == ISO_RES_ALLOC) {
+ r->resource.release = release_iso_resource;
+ ret = add_client_resource(client, &r->resource, GFP_KERNEL);
+ } else {
+ r->resource.release = NULL;
+ r->resource.handle = -1;
+ ret = schedule_iso_resource(r) ? 0 : -ENOMEM;
+ }
if (ret < 0)
goto fail;
request->handle = r->resource.handle;
@@ -1173,6 +1191,13 @@ static int ioctl_allocate_iso_resource(s
return ret;
}
+static int ioctl_allocate_iso_resource(struct client *client, void *buffer)
+{
+ struct fw_cdev_allocate_iso_resource *request = buffer;
+
+ return init_iso_resource(client, request, ISO_RES_ALLOC);
+}
+
static int ioctl_deallocate_iso_resource(struct client *client, void *buffer)
{
struct fw_cdev_deallocate *request = buffer;
@@ -1181,6 +1206,20 @@ static int ioctl_deallocate_iso_resource
release_iso_resource, NULL);
}
+static int ioctl_allocate_iso_resource_once(struct client *client, void *buffer)
+{
+ struct fw_cdev_allocate_iso_resource *request = buffer;
+
+ return init_iso_resource(client, request, ISO_RES_ALLOC_ONCE);
+}
+
+static int ioctl_deallocate_iso_resource_once(struct client *client, void *buffer)
+{
+ struct fw_cdev_allocate_iso_resource *request = buffer;
+
+ return init_iso_resource(client, request, ISO_RES_DEALLOC_ONCE);
+}
+
static int (* const ioctl_handlers[])(struct client *client, void *buffer) = {
ioctl_get_info,
ioctl_send_request,
@@ -1197,6 +1236,8 @@ static int (* const ioctl_handlers[])(st
ioctl_get_cycle_timer,
ioctl_allocate_iso_resource,
ioctl_deallocate_iso_resource,
+ ioctl_allocate_iso_resource_once,
+ ioctl_deallocate_iso_resource_once,
};
static int dispatch_ioctl(struct client *client,
--
Stefan Richter
-=====-==--= ---= --=--
http://arcgraph.de/sr/
--
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