linux/drivers/firewire/core-cdev.c

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/*
* Char device for device raw access
*
* Copyright (C) 2005-2007 Kristian Hoegsberg <krh@bitplanet.net>
*
* 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
#include <linux/bug.h>
#include <linux/compat.h>
#include <linux/delay.h>
#include <linux/device.h>
#include <linux/errno.h>
#include <linux/firewire.h>
#include <linux/firewire-cdev.h>
#include <linux/idr.h>
#include <linux/irqflags.h>
#include <linux/jiffies.h>
#include <linux/kernel.h>
#include <linux/kref.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/poll.h>
#include <linux/sched.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/time.h>
#include <linux/uaccess.h>
#include <linux/vmalloc.h>
#include <linux/wait.h>
#include <linux/workqueue.h>
#include <asm/system.h>
#include "core.h"
/*
* ABI version history is documented in linux/firewire-cdev.h.
*/
firewire: cdev: fix ABI for FCP and address range mapping, add fw_cdev_event_request2 The problem: A target-like userspace driver, e.g. AV/C target or SBP-2/3 target, needs to be able to act as responder and requester. In the latter role, it needs to send requests to nods from which it received requests. This is currently impossible because fw_cdev_event_request lacks information about sender node ID. Reported-by: Jay Fenlason <fenlason@redhat.com> Libffado + libraw1394 + firewire-core is currently unable to drive two or more audio devices on the same bus. Reported-by: Arnold Krille <arnold@arnoldarts.de> This is because libffado requires destination node ID of FCP requests and sender node ID of FCP responses to match. It even prohibits libffado from working with a bus on which libraw1394 opens a /dev/fw* as default ioctl device that does not correspond with the audio device. This is because libraw1394 does not receive the sender node ID from the kernel. Moreover, fw_cdev_event_request makes it impossible to tell unicast and broadcast write requests apart. The fix: Add a replacement of struct fw_cdev_event_request request, boringly called struct fw_cdev_event_request2. The new event will be sent to a userspace client instead of the old one if the client claims compatibility with <linux/firewire-cdev.h> ABI version 4 or later. libraw1394 needs to be extended to make use of the new event, in order to properly support libffado and other FCP or address range mapping users who require correct sender node IDs. Further notes: While we are at it, change back the range of possible values of fw_cdev_event_request.tcode to 0x0...0xb like in ABI version <= 3. The preceding change "firewire: expose extended tcode of incoming lock requests to (userspace) drivers" expanded it to 0x0...0x17 which could catch sloppily coded clients by surprise. The extended range of codes is only used in the new fw_cdev_event_request2.tcode. Jay and I also suggested an alternative approach to fix the ABI for incoming requests: Add an FW_CDEV_IOC_GET_REQUEST_INFO ioctl which can be called after reception of an fw_cdev_event_request, before issuing of the closing FW_CDEV_IOC_SEND_RESPONSE ioctl. The new ioctl would reveal the vital information about a request that fw_cdev_event_request lacks. Jay showed an implementation of this approach. The former event approach adds 27 LOC of rather trivial code to core-cdev.c, the ioctl approach 34 LOC, some of which is nontrivial. The ioctl approach would certainly also add more LOC to userspace programs which require the expanded information on inbound requests. This approach is probably only on the lighter-weight side in case of clients that want to be compatible with kernels that lack the new capability, like libraw1394. However, the code to be added to such libraw1394-like clients in case of the event approach is a straight- forward additional switch () case in its event handler. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-06-20 20:53:55 +00:00
#define FW_CDEV_KERNEL_VERSION 4
#define FW_CDEV_VERSION_EVENT_REQUEST2 4
struct client {
u32 version;
struct fw_device *device;
spinlock_t lock;
bool in_shutdown;
struct idr resource_idr;
struct list_head event_list;
wait_queue_head_t wait;
u64 bus_reset_closure;
struct fw_iso_context *iso_context;
u64 iso_closure;
struct fw_iso_buffer buffer;
unsigned long vm_start;
struct list_head link;
struct kref kref;
};
static inline void client_get(struct client *client)
{
kref_get(&client->kref);
}
static void client_release(struct kref *kref)
{
struct client *client = container_of(kref, struct client, kref);
fw_device_put(client->device);
kfree(client);
}
static void client_put(struct client *client)
{
kref_put(&client->kref, client_release);
}
struct client_resource;
typedef void (*client_resource_release_fn_t)(struct client *,
struct client_resource *);
struct client_resource {
client_resource_release_fn_t release;
int handle;
};
struct address_handler_resource {
struct client_resource resource;
struct fw_address_handler handler;
__u64 closure;
struct client *client;
};
struct outbound_transaction_resource {
struct client_resource resource;
struct fw_transaction transaction;
};
struct inbound_transaction_resource {
struct client_resource resource;
firewire: cdev: fix responses to nodes at different card My box has two firewire cards in it: card0 and card1. My application opens /dev/fw0 (card 0) and allocates an address space. The core makes the address space available on both cards. Along comes the remote device, which sends a READ_QUADLET_REQUEST to card1. The request gets passed up to my application, which calls ioctl_send_response(). ioctl_send_response() then calls fw_send_response() with card0, because that's the card it's bound to. Card0's driver drops the response, because it isn't part of a transaction that it has outstanding. So in core-cdev: handle_request(), we need to stash the card of the inbound request in the struct inbound_transaction_resource and use that card to send the response to. The hard part will be refcounting the card correctly so it can't get deallocated while we hold a pointer to it. Here's a trivial patch, which does not do the card refcounting, but at least demonstrates what the problem is. Note that we can't depend on the fact that the core-cdev:client structure holds a card open, because in this case the card it holds open is not the card the request came in on. ..and there's no way for the core to tell cdev "this card is gone, kill any inbound transactions on it", while cdev holds the transaction open until userspace issues a SEND_RESPONSE ioctl, which may be a very, very long time. But when it does, it calls fw_send_response(), which will dereference the card... So how unhappy are we about userspace potentially holding a fw_card open forever? Signed-off-by: Jay Fenlason <fenlason@redhat.com> Reference counting to be addressed in a separate change. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (whitespace)
2010-05-18 18:02:45 +00:00
struct fw_card *card;
struct fw_request *request;
void *data;
size_t length;
};
struct descriptor_resource {
struct client_resource resource;
struct fw_descriptor descriptor;
u32 data[0];
};
struct iso_resource {
struct client_resource 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,
ISO_RES_ALLOC_ONCE, ISO_RES_DEALLOC_ONCE,} todo;
int generation;
u64 channels;
s32 bandwidth;
__be32 transaction_data[2];
struct iso_resource_event *e_alloc, *e_dealloc;
};
static void release_iso_resource(struct client *, struct client_resource *);
static void schedule_iso_resource(struct iso_resource *r, unsigned long delay)
{
client_get(r->client);
if (!schedule_delayed_work(&r->work, delay))
client_put(r->client);
}
static void schedule_if_iso_resource(struct client_resource *resource)
{
if (resource->release == release_iso_resource)
schedule_iso_resource(container_of(resource,
struct iso_resource, resource), 0);
}
/*
* dequeue_event() just kfree()'s the event, so the event has to be
* the first field in a struct XYZ_event.
*/
struct event {
struct { void *data; size_t size; } v[2];
struct list_head link;
};
struct bus_reset_event {
struct event event;
struct fw_cdev_event_bus_reset reset;
};
struct outbound_transaction_event {
struct event event;
struct client *client;
struct outbound_transaction_resource r;
struct fw_cdev_event_response response;
};
struct inbound_transaction_event {
struct event event;
firewire: cdev: fix ABI for FCP and address range mapping, add fw_cdev_event_request2 The problem: A target-like userspace driver, e.g. AV/C target or SBP-2/3 target, needs to be able to act as responder and requester. In the latter role, it needs to send requests to nods from which it received requests. This is currently impossible because fw_cdev_event_request lacks information about sender node ID. Reported-by: Jay Fenlason <fenlason@redhat.com> Libffado + libraw1394 + firewire-core is currently unable to drive two or more audio devices on the same bus. Reported-by: Arnold Krille <arnold@arnoldarts.de> This is because libffado requires destination node ID of FCP requests and sender node ID of FCP responses to match. It even prohibits libffado from working with a bus on which libraw1394 opens a /dev/fw* as default ioctl device that does not correspond with the audio device. This is because libraw1394 does not receive the sender node ID from the kernel. Moreover, fw_cdev_event_request makes it impossible to tell unicast and broadcast write requests apart. The fix: Add a replacement of struct fw_cdev_event_request request, boringly called struct fw_cdev_event_request2. The new event will be sent to a userspace client instead of the old one if the client claims compatibility with <linux/firewire-cdev.h> ABI version 4 or later. libraw1394 needs to be extended to make use of the new event, in order to properly support libffado and other FCP or address range mapping users who require correct sender node IDs. Further notes: While we are at it, change back the range of possible values of fw_cdev_event_request.tcode to 0x0...0xb like in ABI version <= 3. The preceding change "firewire: expose extended tcode of incoming lock requests to (userspace) drivers" expanded it to 0x0...0x17 which could catch sloppily coded clients by surprise. The extended range of codes is only used in the new fw_cdev_event_request2.tcode. Jay and I also suggested an alternative approach to fix the ABI for incoming requests: Add an FW_CDEV_IOC_GET_REQUEST_INFO ioctl which can be called after reception of an fw_cdev_event_request, before issuing of the closing FW_CDEV_IOC_SEND_RESPONSE ioctl. The new ioctl would reveal the vital information about a request that fw_cdev_event_request lacks. Jay showed an implementation of this approach. The former event approach adds 27 LOC of rather trivial code to core-cdev.c, the ioctl approach 34 LOC, some of which is nontrivial. The ioctl approach would certainly also add more LOC to userspace programs which require the expanded information on inbound requests. This approach is probably only on the lighter-weight side in case of clients that want to be compatible with kernels that lack the new capability, like libraw1394. However, the code to be added to such libraw1394-like clients in case of the event approach is a straight- forward additional switch () case in its event handler. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-06-20 20:53:55 +00:00
union {
struct fw_cdev_event_request request;
struct fw_cdev_event_request2 request2;
} req;
};
struct iso_interrupt_event {
struct event event;
struct fw_cdev_event_iso_interrupt interrupt;
};
struct iso_resource_event {
struct event event;
struct fw_cdev_event_iso_resource iso_resource;
};
static inline void __user *u64_to_uptr(__u64 value)
{
return (void __user *)(unsigned long)value;
}
static inline __u64 uptr_to_u64(void __user *ptr)
{
return (__u64)(unsigned long)ptr;
}
static int fw_device_op_open(struct inode *inode, struct file *file)
{
struct fw_device *device;
struct client *client;
device = fw_device_get_by_devt(inode->i_rdev);
if (device == NULL)
return -ENODEV;
if (fw_device_is_shutdown(device)) {
fw_device_put(device);
return -ENODEV;
}
client = kzalloc(sizeof(*client), GFP_KERNEL);
if (client == NULL) {
fw_device_put(device);
return -ENOMEM;
}
client->device = device;
spin_lock_init(&client->lock);
idr_init(&client->resource_idr);
INIT_LIST_HEAD(&client->event_list);
init_waitqueue_head(&client->wait);
kref_init(&client->kref);
file->private_data = client;
mutex_lock(&device->client_list_mutex);
list_add_tail(&client->link, &device->client_list);
mutex_unlock(&device->client_list_mutex);
return nonseekable_open(inode, file);
}
static void queue_event(struct client *client, struct event *event,
void *data0, size_t size0, void *data1, size_t size1)
{
unsigned long flags;
event->v[0].data = data0;
event->v[0].size = size0;
event->v[1].data = data1;
event->v[1].size = size1;
spin_lock_irqsave(&client->lock, flags);
if (client->in_shutdown)
kfree(event);
else
list_add_tail(&event->link, &client->event_list);
spin_unlock_irqrestore(&client->lock, flags);
wake_up_interruptible(&client->wait);
}
static int dequeue_event(struct client *client,
char __user *buffer, size_t count)
{
struct event *event;
size_t size, total;
int i, ret;
ret = wait_event_interruptible(client->wait,
!list_empty(&client->event_list) ||
fw_device_is_shutdown(client->device));
if (ret < 0)
return ret;
if (list_empty(&client->event_list) &&
fw_device_is_shutdown(client->device))
return -ENODEV;
spin_lock_irq(&client->lock);
event = list_first_entry(&client->event_list, struct event, link);
list_del(&event->link);
spin_unlock_irq(&client->lock);
total = 0;
for (i = 0; i < ARRAY_SIZE(event->v) && total < count; i++) {
size = min(event->v[i].size, count - total);
if (copy_to_user(buffer + total, event->v[i].data, size)) {
ret = -EFAULT;
goto out;
}
total += size;
}
ret = total;
out:
kfree(event);
return ret;
}
static ssize_t fw_device_op_read(struct file *file, char __user *buffer,
size_t count, loff_t *offset)
{
struct client *client = file->private_data;
return dequeue_event(client, buffer, count);
}
static void fill_bus_reset_event(struct fw_cdev_event_bus_reset *event,
struct client *client)
{
struct fw_card *card = client->device->card;
spin_lock_irq(&card->lock);
event->closure = client->bus_reset_closure;
event->type = FW_CDEV_EVENT_BUS_RESET;
event->generation = client->device->generation;
event->node_id = client->device->node_id;
event->local_node_id = card->local_node->node_id;
event->bm_node_id = card->bm_node_id;
event->irm_node_id = card->irm_node->node_id;
event->root_node_id = card->root_node->node_id;
spin_unlock_irq(&card->lock);
}
static void for_each_client(struct fw_device *device,
void (*callback)(struct client *client))
{
struct client *c;
mutex_lock(&device->client_list_mutex);
list_for_each_entry(c, &device->client_list, link)
callback(c);
mutex_unlock(&device->client_list_mutex);
}
static int schedule_reallocations(int id, void *p, void *data)
{
schedule_if_iso_resource(p);
return 0;
}
static void queue_bus_reset_event(struct client *client)
{
struct bus_reset_event *e;
e = kzalloc(sizeof(*e), GFP_KERNEL);
if (e == NULL) {
fw_notify("Out of memory when allocating bus reset event\n");
return;
}
fill_bus_reset_event(&e->reset, client);
queue_event(client, &e->event,
&e->reset, sizeof(e->reset), NULL, 0);
spin_lock_irq(&client->lock);
idr_for_each(&client->resource_idr, schedule_reallocations, client);
spin_unlock_irq(&client->lock);
}
void fw_device_cdev_update(struct fw_device *device)
{
for_each_client(device, queue_bus_reset_event);
}
static void wake_up_client(struct client *client)
{
wake_up_interruptible(&client->wait);
}
void fw_device_cdev_remove(struct fw_device *device)
{
for_each_client(device, wake_up_client);
}
union ioctl_arg {
struct fw_cdev_get_info get_info;
struct fw_cdev_send_request send_request;
struct fw_cdev_allocate allocate;
struct fw_cdev_deallocate deallocate;
struct fw_cdev_send_response send_response;
struct fw_cdev_initiate_bus_reset initiate_bus_reset;
struct fw_cdev_add_descriptor add_descriptor;
struct fw_cdev_remove_descriptor remove_descriptor;
struct fw_cdev_create_iso_context create_iso_context;
struct fw_cdev_queue_iso queue_iso;
struct fw_cdev_start_iso start_iso;
struct fw_cdev_stop_iso stop_iso;
struct fw_cdev_get_cycle_timer get_cycle_timer;
struct fw_cdev_allocate_iso_resource allocate_iso_resource;
struct fw_cdev_send_stream_packet send_stream_packet;
struct fw_cdev_get_cycle_timer2 get_cycle_timer2;
};
static int ioctl_get_info(struct client *client, union ioctl_arg *arg)
{
struct fw_cdev_get_info *a = &arg->get_info;
struct fw_cdev_event_bus_reset bus_reset;
unsigned long ret = 0;
client->version = a->version;
a->version = FW_CDEV_KERNEL_VERSION;
a->card = client->device->card->index;
down_read(&fw_device_rwsem);
if (a->rom != 0) {
size_t want = a->rom_length;
size_t have = client->device->config_rom_length * 4;
ret = copy_to_user(u64_to_uptr(a->rom),
client->device->config_rom, min(want, have));
}
a->rom_length = client->device->config_rom_length * 4;
up_read(&fw_device_rwsem);
if (ret != 0)
return -EFAULT;
client->bus_reset_closure = a->bus_reset_closure;
if (a->bus_reset != 0) {
fill_bus_reset_event(&bus_reset, client);
if (copy_to_user(u64_to_uptr(a->bus_reset),
&bus_reset, sizeof(bus_reset)))
return -EFAULT;
}
return 0;
}
static int add_client_resource(struct client *client,
struct client_resource *resource, gfp_t gfp_mask)
{
unsigned long flags;
int ret;
retry:
if (idr_pre_get(&client->resource_idr, gfp_mask) == 0)
return -ENOMEM;
spin_lock_irqsave(&client->lock, flags);
if (client->in_shutdown)
ret = -ECANCELED;
else
ret = idr_get_new(&client->resource_idr, resource,
&resource->handle);
if (ret >= 0) {
client_get(client);
schedule_if_iso_resource(resource);
}
spin_unlock_irqrestore(&client->lock, flags);
if (ret == -EAGAIN)
goto retry;
return ret < 0 ? ret : 0;
}
static int release_client_resource(struct client *client, u32 handle,
client_resource_release_fn_t release,
struct client_resource **return_resource)
{
struct client_resource *resource;
spin_lock_irq(&client->lock);
if (client->in_shutdown)
resource = NULL;
else
resource = idr_find(&client->resource_idr, handle);
if (resource && resource->release == release)
idr_remove(&client->resource_idr, handle);
spin_unlock_irq(&client->lock);
if (!(resource && resource->release == release))
return -EINVAL;
if (return_resource)
*return_resource = resource;
else
resource->release(client, resource);
client_put(client);
return 0;
}
static void release_transaction(struct client *client,
struct client_resource *resource)
{
struct outbound_transaction_resource *r = container_of(resource,
struct outbound_transaction_resource, resource);
fw_cancel_transaction(client->device->card, &r->transaction);
}
static void complete_transaction(struct fw_card *card, int rcode,
void *payload, size_t length, void *data)
{
struct outbound_transaction_event *e = data;
struct fw_cdev_event_response *rsp = &e->response;
struct client *client = e->client;
unsigned long flags;
if (length < rsp->length)
rsp->length = length;
if (rcode == RCODE_COMPLETE)
memcpy(rsp->data, payload, rsp->length);
spin_lock_irqsave(&client->lock, flags);
/*
* 1. If called while in shutdown, the idr tree must be left untouched.
* The idr handle will be removed and the client reference will be
* dropped later.
* 2. If the call chain was release_client_resource ->
* release_transaction -> complete_transaction (instead of a normal
* conclusion of the transaction), i.e. if this resource was already
* unregistered from the idr, the client reference will be dropped
* by release_client_resource and we must not drop it here.
*/
if (!client->in_shutdown &&
idr_find(&client->resource_idr, e->r.resource.handle)) {
idr_remove(&client->resource_idr, e->r.resource.handle);
/* Drop the idr's reference */
client_put(client);
}
spin_unlock_irqrestore(&client->lock, flags);
rsp->type = FW_CDEV_EVENT_RESPONSE;
rsp->rcode = rcode;
/*
* In the case that sizeof(*rsp) doesn't align with the position of the
* data, and the read is short, preserve an extra copy of the data
* to stay compatible with a pre-2.6.27 bug. Since the bug is harmless
* for short reads and some apps depended on it, this is both safe
* and prudent for compatibility.
*/
if (rsp->length <= sizeof(*rsp) - offsetof(typeof(*rsp), data))
queue_event(client, &e->event, rsp, sizeof(*rsp),
rsp->data, rsp->length);
else
queue_event(client, &e->event, rsp, sizeof(*rsp) + rsp->length,
NULL, 0);
/* Drop the transaction callback's reference */
client_put(client);
}
static int init_request(struct client *client,
struct fw_cdev_send_request *request,
int destination_id, int speed)
{
struct outbound_transaction_event *e;
int ret;
if (request->tcode != TCODE_STREAM_DATA &&
(request->length > 4096 || request->length > 512 << speed))
return -EIO;
if (request->tcode == TCODE_WRITE_QUADLET_REQUEST &&
request->length < 4)
return -EINVAL;
e = kmalloc(sizeof(*e) + request->length, GFP_KERNEL);
if (e == NULL)
return -ENOMEM;
e->client = client;
e->response.length = request->length;
e->response.closure = request->closure;
if (request->data &&
copy_from_user(e->response.data,
u64_to_uptr(request->data), request->length)) {
ret = -EFAULT;
goto failed;
}
e->r.resource.release = release_transaction;
ret = add_client_resource(client, &e->r.resource, GFP_KERNEL);
if (ret < 0)
goto failed;
/* Get a reference for the transaction callback */
client_get(client);
fw_send_request(client->device->card, &e->r.transaction,
request->tcode, destination_id, request->generation,
speed, request->offset, e->response.data,
request->length, complete_transaction, e);
return 0;
failed:
kfree(e);
return ret;
}
static int ioctl_send_request(struct client *client, union ioctl_arg *arg)
{
switch (arg->send_request.tcode) {
case TCODE_WRITE_QUADLET_REQUEST:
case TCODE_WRITE_BLOCK_REQUEST:
case TCODE_READ_QUADLET_REQUEST:
case TCODE_READ_BLOCK_REQUEST:
case TCODE_LOCK_MASK_SWAP:
case TCODE_LOCK_COMPARE_SWAP:
case TCODE_LOCK_FETCH_ADD:
case TCODE_LOCK_LITTLE_ADD:
case TCODE_LOCK_BOUNDED_ADD:
case TCODE_LOCK_WRAP_ADD:
case TCODE_LOCK_VENDOR_DEPENDENT:
break;
default:
return -EINVAL;
}
return init_request(client, &arg->send_request, client->device->node_id,
client->device->max_speed);
}
static inline bool is_fcp_request(struct fw_request *request)
{
return request == NULL;
}
static void release_request(struct client *client,
struct client_resource *resource)
{
struct inbound_transaction_resource *r = container_of(resource,
struct inbound_transaction_resource, resource);
if (is_fcp_request(r->request))
kfree(r->data);
else
firewire: cdev: fix responses to nodes at different card My box has two firewire cards in it: card0 and card1. My application opens /dev/fw0 (card 0) and allocates an address space. The core makes the address space available on both cards. Along comes the remote device, which sends a READ_QUADLET_REQUEST to card1. The request gets passed up to my application, which calls ioctl_send_response(). ioctl_send_response() then calls fw_send_response() with card0, because that's the card it's bound to. Card0's driver drops the response, because it isn't part of a transaction that it has outstanding. So in core-cdev: handle_request(), we need to stash the card of the inbound request in the struct inbound_transaction_resource and use that card to send the response to. The hard part will be refcounting the card correctly so it can't get deallocated while we hold a pointer to it. Here's a trivial patch, which does not do the card refcounting, but at least demonstrates what the problem is. Note that we can't depend on the fact that the core-cdev:client structure holds a card open, because in this case the card it holds open is not the card the request came in on. ..and there's no way for the core to tell cdev "this card is gone, kill any inbound transactions on it", while cdev holds the transaction open until userspace issues a SEND_RESPONSE ioctl, which may be a very, very long time. But when it does, it calls fw_send_response(), which will dereference the card... So how unhappy are we about userspace potentially holding a fw_card open forever? Signed-off-by: Jay Fenlason <fenlason@redhat.com> Reference counting to be addressed in a separate change. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (whitespace)
2010-05-18 18:02:45 +00:00
fw_send_response(r->card, r->request, RCODE_CONFLICT_ERROR);
firewire: cdev: count references of cards during inbound transactions If a request comes in to an address range managed by a userspace driver i.e. <linux/firewire-cdev.h> client, the card instance of request and response may differ from the card instance of the client device. Therefore we need to take a reference of the card until the response was sent. I thought about putting the reference counting into core-transaction.c, but the various high-level drivers besides cdev clients (firewire-net, firewire-sbp2, firedtv) use the card pointer in their fw_address_handler address_callback method only to look up devices of which they already hold the necessary references. So this seems to be a specific firewire-cdev issue which is better addressed locally. We do not need the reference - in case of FCP_REQUEST or FCP_RESPONSE requests because then the firewire-core will send the split transaction response for us already in the context of the request handler, - if it is the same card as the client device's because we hold a card reference indirectly via teh client->device reference. To keep things simple, we take the reference nevertheless. Jay Fenlason wrote: > there's no way for the core to tell cdev "this card is gone, > kill any inbound transactions on it", while cdev holds the transaction > open until userspace issues a SEND_RESPONSE ioctl, which may be a very, > very long time. But when it does, it calls fw_send_response(), which > will dereference the card... > > So how unhappy are we about userspace potentially holding a fw_card > open forever? While termination of inbound transcations at card removal could be implemented, it is IMO not worth the effort. Currently, the effect of holding a reference of a card that has been removed is to block the process that called the pci_remove of the card. This is - either a user process ran by root. Root can find and kill processes that have /dev/fw* open, if desired. - a kernel thread (which one?) in case of hot removal of a PCCard or ExpressCard. The latter case could be a problem indeed. firewire-core's card shutdown and card release should probably be improved not to block in shutdown, just to defer freeing of memory until release. This is not a new problem though; the same already always happens with the client->device->card without the need of inbound transactions or other special conditions involved, other than the client not closing the file. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-06-20 20:52:27 +00:00
fw_card_put(r->card);
kfree(r);
}
static void handle_request(struct fw_card *card, struct fw_request *request,
int tcode, int destination, int source,
int generation, unsigned long long offset,
void *payload, size_t length, void *callback_data)
{
struct address_handler_resource *handler = callback_data;
struct inbound_transaction_resource *r;
struct inbound_transaction_event *e;
firewire: cdev: fix ABI for FCP and address range mapping, add fw_cdev_event_request2 The problem: A target-like userspace driver, e.g. AV/C target or SBP-2/3 target, needs to be able to act as responder and requester. In the latter role, it needs to send requests to nods from which it received requests. This is currently impossible because fw_cdev_event_request lacks information about sender node ID. Reported-by: Jay Fenlason <fenlason@redhat.com> Libffado + libraw1394 + firewire-core is currently unable to drive two or more audio devices on the same bus. Reported-by: Arnold Krille <arnold@arnoldarts.de> This is because libffado requires destination node ID of FCP requests and sender node ID of FCP responses to match. It even prohibits libffado from working with a bus on which libraw1394 opens a /dev/fw* as default ioctl device that does not correspond with the audio device. This is because libraw1394 does not receive the sender node ID from the kernel. Moreover, fw_cdev_event_request makes it impossible to tell unicast and broadcast write requests apart. The fix: Add a replacement of struct fw_cdev_event_request request, boringly called struct fw_cdev_event_request2. The new event will be sent to a userspace client instead of the old one if the client claims compatibility with <linux/firewire-cdev.h> ABI version 4 or later. libraw1394 needs to be extended to make use of the new event, in order to properly support libffado and other FCP or address range mapping users who require correct sender node IDs. Further notes: While we are at it, change back the range of possible values of fw_cdev_event_request.tcode to 0x0...0xb like in ABI version <= 3. The preceding change "firewire: expose extended tcode of incoming lock requests to (userspace) drivers" expanded it to 0x0...0x17 which could catch sloppily coded clients by surprise. The extended range of codes is only used in the new fw_cdev_event_request2.tcode. Jay and I also suggested an alternative approach to fix the ABI for incoming requests: Add an FW_CDEV_IOC_GET_REQUEST_INFO ioctl which can be called after reception of an fw_cdev_event_request, before issuing of the closing FW_CDEV_IOC_SEND_RESPONSE ioctl. The new ioctl would reveal the vital information about a request that fw_cdev_event_request lacks. Jay showed an implementation of this approach. The former event approach adds 27 LOC of rather trivial code to core-cdev.c, the ioctl approach 34 LOC, some of which is nontrivial. The ioctl approach would certainly also add more LOC to userspace programs which require the expanded information on inbound requests. This approach is probably only on the lighter-weight side in case of clients that want to be compatible with kernels that lack the new capability, like libraw1394. However, the code to be added to such libraw1394-like clients in case of the event approach is a straight- forward additional switch () case in its event handler. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-06-20 20:53:55 +00:00
size_t event_size0;
void *fcp_frame = NULL;
int ret;
firewire: cdev: count references of cards during inbound transactions If a request comes in to an address range managed by a userspace driver i.e. <linux/firewire-cdev.h> client, the card instance of request and response may differ from the card instance of the client device. Therefore we need to take a reference of the card until the response was sent. I thought about putting the reference counting into core-transaction.c, but the various high-level drivers besides cdev clients (firewire-net, firewire-sbp2, firedtv) use the card pointer in their fw_address_handler address_callback method only to look up devices of which they already hold the necessary references. So this seems to be a specific firewire-cdev issue which is better addressed locally. We do not need the reference - in case of FCP_REQUEST or FCP_RESPONSE requests because then the firewire-core will send the split transaction response for us already in the context of the request handler, - if it is the same card as the client device's because we hold a card reference indirectly via teh client->device reference. To keep things simple, we take the reference nevertheless. Jay Fenlason wrote: > there's no way for the core to tell cdev "this card is gone, > kill any inbound transactions on it", while cdev holds the transaction > open until userspace issues a SEND_RESPONSE ioctl, which may be a very, > very long time. But when it does, it calls fw_send_response(), which > will dereference the card... > > So how unhappy are we about userspace potentially holding a fw_card > open forever? While termination of inbound transcations at card removal could be implemented, it is IMO not worth the effort. Currently, the effect of holding a reference of a card that has been removed is to block the process that called the pci_remove of the card. This is - either a user process ran by root. Root can find and kill processes that have /dev/fw* open, if desired. - a kernel thread (which one?) in case of hot removal of a PCCard or ExpressCard. The latter case could be a problem indeed. firewire-core's card shutdown and card release should probably be improved not to block in shutdown, just to defer freeing of memory until release. This is not a new problem though; the same already always happens with the client->device->card without the need of inbound transactions or other special conditions involved, other than the client not closing the file. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-06-20 20:52:27 +00:00
/* card may be different from handler->client->device->card */
fw_card_get(card);
r = kmalloc(sizeof(*r), GFP_ATOMIC);
e = kmalloc(sizeof(*e), GFP_ATOMIC);
if (r == NULL || e == NULL)
goto failed;
firewire: cdev: fix responses to nodes at different card My box has two firewire cards in it: card0 and card1. My application opens /dev/fw0 (card 0) and allocates an address space. The core makes the address space available on both cards. Along comes the remote device, which sends a READ_QUADLET_REQUEST to card1. The request gets passed up to my application, which calls ioctl_send_response(). ioctl_send_response() then calls fw_send_response() with card0, because that's the card it's bound to. Card0's driver drops the response, because it isn't part of a transaction that it has outstanding. So in core-cdev: handle_request(), we need to stash the card of the inbound request in the struct inbound_transaction_resource and use that card to send the response to. The hard part will be refcounting the card correctly so it can't get deallocated while we hold a pointer to it. Here's a trivial patch, which does not do the card refcounting, but at least demonstrates what the problem is. Note that we can't depend on the fact that the core-cdev:client structure holds a card open, because in this case the card it holds open is not the card the request came in on. ..and there's no way for the core to tell cdev "this card is gone, kill any inbound transactions on it", while cdev holds the transaction open until userspace issues a SEND_RESPONSE ioctl, which may be a very, very long time. But when it does, it calls fw_send_response(), which will dereference the card... So how unhappy are we about userspace potentially holding a fw_card open forever? Signed-off-by: Jay Fenlason <fenlason@redhat.com> Reference counting to be addressed in a separate change. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (whitespace)
2010-05-18 18:02:45 +00:00
r->card = card;
r->request = request;
r->data = payload;
r->length = length;
if (is_fcp_request(request)) {
/*
* FIXME: Let core-transaction.c manage a
* single reference-counted copy?
*/
fcp_frame = kmemdup(payload, length, GFP_ATOMIC);
if (fcp_frame == NULL)
goto failed;
r->data = fcp_frame;
}
r->resource.release = release_request;
ret = add_client_resource(handler->client, &r->resource, GFP_ATOMIC);
if (ret < 0)
goto failed;
firewire: cdev: fix ABI for FCP and address range mapping, add fw_cdev_event_request2 The problem: A target-like userspace driver, e.g. AV/C target or SBP-2/3 target, needs to be able to act as responder and requester. In the latter role, it needs to send requests to nods from which it received requests. This is currently impossible because fw_cdev_event_request lacks information about sender node ID. Reported-by: Jay Fenlason <fenlason@redhat.com> Libffado + libraw1394 + firewire-core is currently unable to drive two or more audio devices on the same bus. Reported-by: Arnold Krille <arnold@arnoldarts.de> This is because libffado requires destination node ID of FCP requests and sender node ID of FCP responses to match. It even prohibits libffado from working with a bus on which libraw1394 opens a /dev/fw* as default ioctl device that does not correspond with the audio device. This is because libraw1394 does not receive the sender node ID from the kernel. Moreover, fw_cdev_event_request makes it impossible to tell unicast and broadcast write requests apart. The fix: Add a replacement of struct fw_cdev_event_request request, boringly called struct fw_cdev_event_request2. The new event will be sent to a userspace client instead of the old one if the client claims compatibility with <linux/firewire-cdev.h> ABI version 4 or later. libraw1394 needs to be extended to make use of the new event, in order to properly support libffado and other FCP or address range mapping users who require correct sender node IDs. Further notes: While we are at it, change back the range of possible values of fw_cdev_event_request.tcode to 0x0...0xb like in ABI version <= 3. The preceding change "firewire: expose extended tcode of incoming lock requests to (userspace) drivers" expanded it to 0x0...0x17 which could catch sloppily coded clients by surprise. The extended range of codes is only used in the new fw_cdev_event_request2.tcode. Jay and I also suggested an alternative approach to fix the ABI for incoming requests: Add an FW_CDEV_IOC_GET_REQUEST_INFO ioctl which can be called after reception of an fw_cdev_event_request, before issuing of the closing FW_CDEV_IOC_SEND_RESPONSE ioctl. The new ioctl would reveal the vital information about a request that fw_cdev_event_request lacks. Jay showed an implementation of this approach. The former event approach adds 27 LOC of rather trivial code to core-cdev.c, the ioctl approach 34 LOC, some of which is nontrivial. The ioctl approach would certainly also add more LOC to userspace programs which require the expanded information on inbound requests. This approach is probably only on the lighter-weight side in case of clients that want to be compatible with kernels that lack the new capability, like libraw1394. However, the code to be added to such libraw1394-like clients in case of the event approach is a straight- forward additional switch () case in its event handler. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-06-20 20:53:55 +00:00
if (handler->client->version < FW_CDEV_VERSION_EVENT_REQUEST2) {
struct fw_cdev_event_request *req = &e->req.request;
if (tcode & 0x10)
tcode = TCODE_LOCK_REQUEST;
req->type = FW_CDEV_EVENT_REQUEST;
req->tcode = tcode;
req->offset = offset;
req->length = length;
req->handle = r->resource.handle;
req->closure = handler->closure;
event_size0 = sizeof(*req);
} else {
struct fw_cdev_event_request2 *req = &e->req.request2;
req->type = FW_CDEV_EVENT_REQUEST2;
req->tcode = tcode;
req->offset = offset;
req->source_node_id = source;
req->destination_node_id = destination;
req->card = card->index;
req->generation = generation;
req->length = length;
req->handle = r->resource.handle;
req->closure = handler->closure;
event_size0 = sizeof(*req);
}
queue_event(handler->client, &e->event,
firewire: cdev: fix ABI for FCP and address range mapping, add fw_cdev_event_request2 The problem: A target-like userspace driver, e.g. AV/C target or SBP-2/3 target, needs to be able to act as responder and requester. In the latter role, it needs to send requests to nods from which it received requests. This is currently impossible because fw_cdev_event_request lacks information about sender node ID. Reported-by: Jay Fenlason <fenlason@redhat.com> Libffado + libraw1394 + firewire-core is currently unable to drive two or more audio devices on the same bus. Reported-by: Arnold Krille <arnold@arnoldarts.de> This is because libffado requires destination node ID of FCP requests and sender node ID of FCP responses to match. It even prohibits libffado from working with a bus on which libraw1394 opens a /dev/fw* as default ioctl device that does not correspond with the audio device. This is because libraw1394 does not receive the sender node ID from the kernel. Moreover, fw_cdev_event_request makes it impossible to tell unicast and broadcast write requests apart. The fix: Add a replacement of struct fw_cdev_event_request request, boringly called struct fw_cdev_event_request2. The new event will be sent to a userspace client instead of the old one if the client claims compatibility with <linux/firewire-cdev.h> ABI version 4 or later. libraw1394 needs to be extended to make use of the new event, in order to properly support libffado and other FCP or address range mapping users who require correct sender node IDs. Further notes: While we are at it, change back the range of possible values of fw_cdev_event_request.tcode to 0x0...0xb like in ABI version <= 3. The preceding change "firewire: expose extended tcode of incoming lock requests to (userspace) drivers" expanded it to 0x0...0x17 which could catch sloppily coded clients by surprise. The extended range of codes is only used in the new fw_cdev_event_request2.tcode. Jay and I also suggested an alternative approach to fix the ABI for incoming requests: Add an FW_CDEV_IOC_GET_REQUEST_INFO ioctl which can be called after reception of an fw_cdev_event_request, before issuing of the closing FW_CDEV_IOC_SEND_RESPONSE ioctl. The new ioctl would reveal the vital information about a request that fw_cdev_event_request lacks. Jay showed an implementation of this approach. The former event approach adds 27 LOC of rather trivial code to core-cdev.c, the ioctl approach 34 LOC, some of which is nontrivial. The ioctl approach would certainly also add more LOC to userspace programs which require the expanded information on inbound requests. This approach is probably only on the lighter-weight side in case of clients that want to be compatible with kernels that lack the new capability, like libraw1394. However, the code to be added to such libraw1394-like clients in case of the event approach is a straight- forward additional switch () case in its event handler. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-06-20 20:53:55 +00:00
&e->req, event_size0, r->data, length);
return;
failed:
kfree(r);
kfree(e);
kfree(fcp_frame);
if (!is_fcp_request(request))
fw_send_response(card, request, RCODE_CONFLICT_ERROR);
firewire: cdev: count references of cards during inbound transactions If a request comes in to an address range managed by a userspace driver i.e. <linux/firewire-cdev.h> client, the card instance of request and response may differ from the card instance of the client device. Therefore we need to take a reference of the card until the response was sent. I thought about putting the reference counting into core-transaction.c, but the various high-level drivers besides cdev clients (firewire-net, firewire-sbp2, firedtv) use the card pointer in their fw_address_handler address_callback method only to look up devices of which they already hold the necessary references. So this seems to be a specific firewire-cdev issue which is better addressed locally. We do not need the reference - in case of FCP_REQUEST or FCP_RESPONSE requests because then the firewire-core will send the split transaction response for us already in the context of the request handler, - if it is the same card as the client device's because we hold a card reference indirectly via teh client->device reference. To keep things simple, we take the reference nevertheless. Jay Fenlason wrote: > there's no way for the core to tell cdev "this card is gone, > kill any inbound transactions on it", while cdev holds the transaction > open until userspace issues a SEND_RESPONSE ioctl, which may be a very, > very long time. But when it does, it calls fw_send_response(), which > will dereference the card... > > So how unhappy are we about userspace potentially holding a fw_card > open forever? While termination of inbound transcations at card removal could be implemented, it is IMO not worth the effort. Currently, the effect of holding a reference of a card that has been removed is to block the process that called the pci_remove of the card. This is - either a user process ran by root. Root can find and kill processes that have /dev/fw* open, if desired. - a kernel thread (which one?) in case of hot removal of a PCCard or ExpressCard. The latter case could be a problem indeed. firewire-core's card shutdown and card release should probably be improved not to block in shutdown, just to defer freeing of memory until release. This is not a new problem though; the same already always happens with the client->device->card without the need of inbound transactions or other special conditions involved, other than the client not closing the file. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-06-20 20:52:27 +00:00
fw_card_put(card);
}
static void release_address_handler(struct client *client,
struct client_resource *resource)
{
struct address_handler_resource *r =
container_of(resource, struct address_handler_resource, resource);
fw_core_remove_address_handler(&r->handler);
kfree(r);
}
static int ioctl_allocate(struct client *client, union ioctl_arg *arg)
{
struct fw_cdev_allocate *a = &arg->allocate;
struct address_handler_resource *r;
struct fw_address_region region;
int ret;
r = kmalloc(sizeof(*r), GFP_KERNEL);
if (r == NULL)
return -ENOMEM;
region.start = a->offset;
region.end = a->offset + a->length;
r->handler.length = a->length;
r->handler.address_callback = handle_request;
r->handler.callback_data = r;
r->closure = a->closure;
r->client = client;
ret = fw_core_add_address_handler(&r->handler, &region);
if (ret < 0) {
kfree(r);
return ret;
}
r->resource.release = release_address_handler;
ret = add_client_resource(client, &r->resource, GFP_KERNEL);
if (ret < 0) {
release_address_handler(client, &r->resource);
return ret;
}
a->handle = r->resource.handle;
return 0;
}
static int ioctl_deallocate(struct client *client, union ioctl_arg *arg)
{
return release_client_resource(client, arg->deallocate.handle,
release_address_handler, NULL);
}
static int ioctl_send_response(struct client *client, union ioctl_arg *arg)
{
struct fw_cdev_send_response *a = &arg->send_response;
struct client_resource *resource;
struct inbound_transaction_resource *r;
int ret = 0;
if (release_client_resource(client, a->handle,
release_request, &resource) < 0)
return -EINVAL;
r = container_of(resource, struct inbound_transaction_resource,
resource);
if (is_fcp_request(r->request))
goto out;
if (a->length != fw_get_response_length(r->request)) {
ret = -EINVAL;
kfree(r->request);
goto out;
}
if (copy_from_user(r->data, u64_to_uptr(a->data), a->length)) {
ret = -EFAULT;
kfree(r->request);
goto out;
}
firewire: cdev: fix responses to nodes at different card My box has two firewire cards in it: card0 and card1. My application opens /dev/fw0 (card 0) and allocates an address space. The core makes the address space available on both cards. Along comes the remote device, which sends a READ_QUADLET_REQUEST to card1. The request gets passed up to my application, which calls ioctl_send_response(). ioctl_send_response() then calls fw_send_response() with card0, because that's the card it's bound to. Card0's driver drops the response, because it isn't part of a transaction that it has outstanding. So in core-cdev: handle_request(), we need to stash the card of the inbound request in the struct inbound_transaction_resource and use that card to send the response to. The hard part will be refcounting the card correctly so it can't get deallocated while we hold a pointer to it. Here's a trivial patch, which does not do the card refcounting, but at least demonstrates what the problem is. Note that we can't depend on the fact that the core-cdev:client structure holds a card open, because in this case the card it holds open is not the card the request came in on. ..and there's no way for the core to tell cdev "this card is gone, kill any inbound transactions on it", while cdev holds the transaction open until userspace issues a SEND_RESPONSE ioctl, which may be a very, very long time. But when it does, it calls fw_send_response(), which will dereference the card... So how unhappy are we about userspace potentially holding a fw_card open forever? Signed-off-by: Jay Fenlason <fenlason@redhat.com> Reference counting to be addressed in a separate change. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (whitespace)
2010-05-18 18:02:45 +00:00
fw_send_response(r->card, r->request, a->rcode);
out:
firewire: cdev: count references of cards during inbound transactions If a request comes in to an address range managed by a userspace driver i.e. <linux/firewire-cdev.h> client, the card instance of request and response may differ from the card instance of the client device. Therefore we need to take a reference of the card until the response was sent. I thought about putting the reference counting into core-transaction.c, but the various high-level drivers besides cdev clients (firewire-net, firewire-sbp2, firedtv) use the card pointer in their fw_address_handler address_callback method only to look up devices of which they already hold the necessary references. So this seems to be a specific firewire-cdev issue which is better addressed locally. We do not need the reference - in case of FCP_REQUEST or FCP_RESPONSE requests because then the firewire-core will send the split transaction response for us already in the context of the request handler, - if it is the same card as the client device's because we hold a card reference indirectly via teh client->device reference. To keep things simple, we take the reference nevertheless. Jay Fenlason wrote: > there's no way for the core to tell cdev "this card is gone, > kill any inbound transactions on it", while cdev holds the transaction > open until userspace issues a SEND_RESPONSE ioctl, which may be a very, > very long time. But when it does, it calls fw_send_response(), which > will dereference the card... > > So how unhappy are we about userspace potentially holding a fw_card > open forever? While termination of inbound transcations at card removal could be implemented, it is IMO not worth the effort. Currently, the effect of holding a reference of a card that has been removed is to block the process that called the pci_remove of the card. This is - either a user process ran by root. Root can find and kill processes that have /dev/fw* open, if desired. - a kernel thread (which one?) in case of hot removal of a PCCard or ExpressCard. The latter case could be a problem indeed. firewire-core's card shutdown and card release should probably be improved not to block in shutdown, just to defer freeing of memory until release. This is not a new problem though; the same already always happens with the client->device->card without the need of inbound transactions or other special conditions involved, other than the client not closing the file. Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-06-20 20:52:27 +00:00
fw_card_put(r->card);
kfree(r);
return ret;
}
static int ioctl_initiate_bus_reset(struct client *client, union ioctl_arg *arg)
{
fw_schedule_bus_reset(client->device->card, true,
arg->initiate_bus_reset.type == FW_CDEV_SHORT_RESET);
return 0;
}
static void release_descriptor(struct client *client,
struct client_resource *resource)
{
struct descriptor_resource *r =
container_of(resource, struct descriptor_resource, resource);
fw_core_remove_descriptor(&r->descriptor);
kfree(r);
}
static int ioctl_add_descriptor(struct client *client, union ioctl_arg *arg)
{
struct fw_cdev_add_descriptor *a = &arg->add_descriptor;
struct descriptor_resource *r;
int ret;
/* Access policy: Allow this ioctl only on local nodes' device files. */
if (!client->device->is_local)
return -ENOSYS;
if (a->length > 256)
return -EINVAL;
r = kmalloc(sizeof(*r) + a->length * 4, GFP_KERNEL);
if (r == NULL)
return -ENOMEM;
if (copy_from_user(r->data, u64_to_uptr(a->data), a->length * 4)) {
ret = -EFAULT;
goto failed;
}
r->descriptor.length = a->length;
r->descriptor.immediate = a->immediate;
r->descriptor.key = a->key;
r->descriptor.data = r->data;
ret = fw_core_add_descriptor(&r->descriptor);
if (ret < 0)
goto failed;
r->resource.release = release_descriptor;
ret = add_client_resource(client, &r->resource, GFP_KERNEL);
if (ret < 0) {
fw_core_remove_descriptor(&r->descriptor);
goto failed;
}
a->handle = r->resource.handle;
return 0;
failed:
kfree(r);
return ret;
}
static int ioctl_remove_descriptor(struct client *client, union ioctl_arg *arg)
{
return release_client_resource(client, arg->remove_descriptor.handle,
release_descriptor, NULL);
}
static void iso_callback(struct fw_iso_context *context, u32 cycle,
size_t header_length, void *header, void *data)
{
struct client *client = data;
struct iso_interrupt_event *e;
e = kmalloc(sizeof(*e) + header_length, GFP_ATOMIC);
if (e == NULL)
return;
e->interrupt.type = FW_CDEV_EVENT_ISO_INTERRUPT;
e->interrupt.closure = client->iso_closure;
e->interrupt.cycle = cycle;
e->interrupt.header_length = header_length;
memcpy(e->interrupt.header, header, header_length);
queue_event(client, &e->event, &e->interrupt,
sizeof(e->interrupt) + header_length, NULL, 0);
}
static int ioctl_create_iso_context(struct client *client, union ioctl_arg *arg)
{
struct fw_cdev_create_iso_context *a = &arg->create_iso_context;
struct fw_iso_context *context;
BUILD_BUG_ON(FW_CDEV_ISO_CONTEXT_TRANSMIT != FW_ISO_CONTEXT_TRANSMIT ||
FW_CDEV_ISO_CONTEXT_RECEIVE != FW_ISO_CONTEXT_RECEIVE);
if (a->channel > 63)
return -EINVAL;
switch (a->type) {
case FW_ISO_CONTEXT_RECEIVE:
if (a->header_size < 4 || (a->header_size & 3))
return -EINVAL;
break;
case FW_ISO_CONTEXT_TRANSMIT:
if (a->speed > SCODE_3200)
return -EINVAL;
break;
default:
return -EINVAL;
}
context = fw_iso_context_create(client->device->card, a->type,
a->channel, a->speed, a->header_size,
iso_callback, client);
if (IS_ERR(context))
return PTR_ERR(context);
/* We only support one context at this time. */
spin_lock_irq(&client->lock);
if (client->iso_context != NULL) {
spin_unlock_irq(&client->lock);
fw_iso_context_destroy(context);
return -EBUSY;
}
client->iso_closure = a->closure;
client->iso_context = context;
spin_unlock_irq(&client->lock);
a->handle = 0;
return 0;
}
/* Macros for decoding the iso packet control header. */
#define GET_PAYLOAD_LENGTH(v) ((v) & 0xffff)
#define GET_INTERRUPT(v) (((v) >> 16) & 0x01)
#define GET_SKIP(v) (((v) >> 17) & 0x01)
#define GET_TAG(v) (((v) >> 18) & 0x03)
#define GET_SY(v) (((v) >> 20) & 0x0f)
#define GET_HEADER_LENGTH(v) (((v) >> 24) & 0xff)
static int ioctl_queue_iso(struct client *client, union ioctl_arg *arg)
{
struct fw_cdev_queue_iso *a = &arg->queue_iso;
struct fw_cdev_iso_packet __user *p, *end, *next;
struct fw_iso_context *ctx = client->iso_context;
unsigned long payload, buffer_end, header_length;
u32 control;
int count;
struct {
struct fw_iso_packet packet;
u8 header[256];
} u;
if (ctx == NULL || a->handle != 0)
return -EINVAL;
/*
* If the user passes a non-NULL data pointer, has mmap()'ed
* the iso buffer, and the pointer points inside the buffer,
* we setup the payload pointers accordingly. Otherwise we
* set them both to 0, which will still let packets with
* payload_length == 0 through. In other words, if no packets
* use the indirect payload, the iso buffer need not be mapped
* and the a->data pointer is ignored.
*/
payload = (unsigned long)a->data - client->vm_start;
buffer_end = client->buffer.page_count << PAGE_SHIFT;
if (a->data == 0 || client->buffer.pages == NULL ||
payload >= buffer_end) {
payload = 0;
buffer_end = 0;
}
p = (struct fw_cdev_iso_packet __user *)u64_to_uptr(a->packets);
if (!access_ok(VERIFY_READ, p, a->size))
return -EFAULT;
end = (void __user *)p + a->size;
count = 0;
while (p < end) {
if (get_user(control, &p->control))
return -EFAULT;
u.packet.payload_length = GET_PAYLOAD_LENGTH(control);
u.packet.interrupt = GET_INTERRUPT(control);
u.packet.skip = GET_SKIP(control);
u.packet.tag = GET_TAG(control);
u.packet.sy = GET_SY(control);
u.packet.header_length = GET_HEADER_LENGTH(control);
if (ctx->type == FW_ISO_CONTEXT_TRANSMIT) {
if (u.packet.header_length % 4 != 0)
return -EINVAL;
header_length = u.packet.header_length;
} else {
/*
* We require that header_length is a multiple of
* the fixed header size, ctx->header_size.
*/
if (ctx->header_size == 0) {
if (u.packet.header_length > 0)
return -EINVAL;
} else if (u.packet.header_length == 0 ||
u.packet.header_length % ctx->header_size != 0) {
return -EINVAL;
}
header_length = 0;
}
next = (struct fw_cdev_iso_packet __user *)
&p->header[header_length / 4];
if (next > end)
return -EINVAL;
if (__copy_from_user
(u.packet.header, p->header, header_length))
return -EFAULT;
if (u.packet.skip && ctx->type == FW_ISO_CONTEXT_TRANSMIT &&
u.packet.header_length + u.packet.payload_length > 0)
return -EINVAL;
if (payload + u.packet.payload_length > buffer_end)
return -EINVAL;
if (fw_iso_context_queue(ctx, &u.packet,
&client->buffer, payload))
break;
p = next;
payload += u.packet.payload_length;
count++;
}
a->size -= uptr_to_u64(p) - a->packets;
a->packets = uptr_to_u64(p);
a->data = client->vm_start + payload;
return count;
}
static int ioctl_start_iso(struct client *client, union ioctl_arg *arg)
{
struct fw_cdev_start_iso *a = &arg->start_iso;
BUILD_BUG_ON(
FW_CDEV_ISO_CONTEXT_MATCH_TAG0 != FW_ISO_CONTEXT_MATCH_TAG0 ||
FW_CDEV_ISO_CONTEXT_MATCH_TAG1 != FW_ISO_CONTEXT_MATCH_TAG1 ||
FW_CDEV_ISO_CONTEXT_MATCH_TAG2 != FW_ISO_CONTEXT_MATCH_TAG2 ||
FW_CDEV_ISO_CONTEXT_MATCH_TAG3 != FW_ISO_CONTEXT_MATCH_TAG3 ||
FW_CDEV_ISO_CONTEXT_MATCH_ALL_TAGS != FW_ISO_CONTEXT_MATCH_ALL_TAGS);
if (client->iso_context == NULL || a->handle != 0)
return -EINVAL;
if (client->iso_context->type == FW_ISO_CONTEXT_RECEIVE &&
(a->tags == 0 || a->tags > 15 || a->sync > 15))
return -EINVAL;
return fw_iso_context_start(client->iso_context,
a->cycle, a->sync, a->tags);
}
static int ioctl_stop_iso(struct client *client, union ioctl_arg *arg)
{
struct fw_cdev_stop_iso *a = &arg->stop_iso;
if (client->iso_context == NULL || a->handle != 0)
return -EINVAL;
return fw_iso_context_stop(client->iso_context);
}
static int ioctl_get_cycle_timer2(struct client *client, union ioctl_arg *arg)
{
struct fw_cdev_get_cycle_timer2 *a = &arg->get_cycle_timer2;
struct fw_card *card = client->device->card;
struct timespec ts = {0, 0};
u32 cycle_time;
int ret = 0;
local_irq_disable();
cycle_time = card->driver->read_csr(card, CSR_CYCLE_TIME);
switch (a->clk_id) {
case CLOCK_REALTIME: getnstimeofday(&ts); break;
case CLOCK_MONOTONIC: do_posix_clock_monotonic_gettime(&ts); break;
case CLOCK_MONOTONIC_RAW: getrawmonotonic(&ts); break;
default:
ret = -EINVAL;
}
local_irq_enable();
a->tv_sec = ts.tv_sec;
a->tv_nsec = ts.tv_nsec;
a->cycle_timer = cycle_time;
return ret;
}
static int ioctl_get_cycle_timer(struct client *client, union ioctl_arg *arg)
{
struct fw_cdev_get_cycle_timer *a = &arg->get_cycle_timer;
struct fw_cdev_get_cycle_timer2 ct2;
ct2.clk_id = CLOCK_REALTIME;
ioctl_get_cycle_timer2(client, (union ioctl_arg *)&ct2);
a->local_time = ct2.tv_sec * USEC_PER_SEC + ct2.tv_nsec / NSEC_PER_USEC;
a->cycle_timer = ct2.cycle_timer;
return 0;
}
static void iso_resource_work(struct work_struct *work)
{
struct iso_resource_event *e;
struct iso_resource *r =
container_of(work, struct iso_resource, work.work);
struct client *client = r->client;
int generation, channel, bandwidth, todo;
bool skip, free, success;
spin_lock_irq(&client->lock);
generation = client->device->generation;
todo = r->todo;
/* Allow 1000ms grace period for other reallocations. */
if (todo == ISO_RES_ALLOC &&
time_is_after_jiffies(client->device->card->reset_jiffies + HZ)) {
schedule_iso_resource(r, DIV_ROUND_UP(HZ, 3));
skip = true;
} else {
/* We could be called twice within the same generation. */
skip = todo == ISO_RES_REALLOC &&
r->generation == generation;
}
free = todo == ISO_RES_DEALLOC ||
todo == ISO_RES_ALLOC_ONCE ||
todo == ISO_RES_DEALLOC_ONCE;
r->generation = generation;
spin_unlock_irq(&client->lock);
if (skip)
goto out;
bandwidth = r->bandwidth;
fw_iso_resource_manage(client->device->card, generation,
r->channels, &channel, &bandwidth,
todo == ISO_RES_ALLOC ||
todo == ISO_RES_REALLOC ||
todo == ISO_RES_ALLOC_ONCE,
r->transaction_data);
/*
* 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
* shutdown.
*/
if (channel == -EAGAIN &&
(todo == ISO_RES_ALLOC || todo == ISO_RES_REALLOC))
goto out;
success = channel >= 0 || bandwidth > 0;
spin_lock_irq(&client->lock);
/*
* Transit from allocation to reallocation, except if the client
* requested deallocation in the meantime.
*/
if (r->todo == ISO_RES_ALLOC)
r->todo = ISO_RES_REALLOC;
/*
* Allocation or reallocation failure? Pull this resource out of the
* idr and prepare for deletion, unless the client is shutting down.
*/
if (r->todo == ISO_RES_REALLOC && !success &&
!client->in_shutdown &&
idr_find(&client->resource_idr, r->resource.handle)) {
idr_remove(&client->resource_idr, r->resource.handle);
client_put(client);
free = true;
}
spin_unlock_irq(&client->lock);
if (todo == ISO_RES_ALLOC && channel >= 0)
r->channels = 1ULL << channel;
if (todo == ISO_RES_REALLOC && success)
goto out;
if (todo == ISO_RES_ALLOC || todo == ISO_RES_ALLOC_ONCE) {
e = r->e_alloc;
r->e_alloc = NULL;
} else {
e = r->e_dealloc;
r->e_dealloc = NULL;
}
e->iso_resource.handle = r->resource.handle;
e->iso_resource.channel = channel;
e->iso_resource.bandwidth = bandwidth;
queue_event(client, &e->event,
&e->iso_resource, sizeof(e->iso_resource), NULL, 0);
if (free) {
cancel_delayed_work(&r->work);
kfree(r->e_alloc);
kfree(r->e_dealloc);
kfree(r);
}
out:
client_put(client);
}
static void release_iso_resource(struct client *client,
struct client_resource *resource)
{
struct iso_resource *r =
container_of(resource, struct iso_resource, resource);
spin_lock_irq(&client->lock);
r->todo = ISO_RES_DEALLOC;
schedule_iso_resource(r, 0);
spin_unlock_irq(&client->lock);
}
static int init_iso_resource(struct client *client,
struct fw_cdev_allocate_iso_resource *request, int todo)
{
struct iso_resource_event *e1, *e2;
struct iso_resource *r;
int ret;
if ((request->channels == 0 && request->bandwidth == 0) ||
request->bandwidth > BANDWIDTH_AVAILABLE_INITIAL ||
request->bandwidth < 0)
return -EINVAL;
r = kmalloc(sizeof(*r), GFP_KERNEL);
e1 = kmalloc(sizeof(*e1), GFP_KERNEL);
e2 = kmalloc(sizeof(*e2), GFP_KERNEL);
if (r == NULL || e1 == NULL || e2 == NULL) {
ret = -ENOMEM;
goto fail;
}
INIT_DELAYED_WORK(&r->work, iso_resource_work);
r->client = client;
r->todo = todo;
r->generation = -1;
r->channels = request->channels;
r->bandwidth = request->bandwidth;
r->e_alloc = e1;
r->e_dealloc = e2;
e1->iso_resource.closure = request->closure;
e1->iso_resource.type = FW_CDEV_EVENT_ISO_RESOURCE_ALLOCATED;
e2->iso_resource.closure = request->closure;
e2->iso_resource.type = FW_CDEV_EVENT_ISO_RESOURCE_DEALLOCATED;
if (todo == ISO_RES_ALLOC) {
r->resource.release = release_iso_resource;
ret = add_client_resource(client, &r->resource, GFP_KERNEL);
if (ret < 0)
goto fail;
} else {
r->resource.release = NULL;
r->resource.handle = -1;
schedule_iso_resource(r, 0);
}
request->handle = r->resource.handle;
return 0;
fail:
kfree(r);
kfree(e1);
kfree(e2);
return ret;
}
static int ioctl_allocate_iso_resource(struct client *client,
union ioctl_arg *arg)
{
return init_iso_resource(client,
&arg->allocate_iso_resource, ISO_RES_ALLOC);
}
static int ioctl_deallocate_iso_resource(struct client *client,
union ioctl_arg *arg)
{
return release_client_resource(client,
arg->deallocate.handle, release_iso_resource, NULL);
}
static int ioctl_allocate_iso_resource_once(struct client *client,
union ioctl_arg *arg)
{
return init_iso_resource(client,
&arg->allocate_iso_resource, ISO_RES_ALLOC_ONCE);
}
static int ioctl_deallocate_iso_resource_once(struct client *client,
union ioctl_arg *arg)
{
return init_iso_resource(client,
&arg->allocate_iso_resource, ISO_RES_DEALLOC_ONCE);
}
/*
* Returns a speed code: Maximum speed to or from this device,
* limited by the device's link speed, the local node's link speed,
* and all PHY port speeds between the two links.
*/
static int ioctl_get_speed(struct client *client, union ioctl_arg *arg)
{
return client->device->max_speed;
}
static int ioctl_send_broadcast_request(struct client *client,
union ioctl_arg *arg)
{
struct fw_cdev_send_request *a = &arg->send_request;
switch (a->tcode) {
case TCODE_WRITE_QUADLET_REQUEST:
case TCODE_WRITE_BLOCK_REQUEST:
break;
default:
return -EINVAL;
}
/* Security policy: Only allow accesses to Units Space. */
if (a->offset < CSR_REGISTER_BASE + CSR_CONFIG_ROM_END)
return -EACCES;
return init_request(client, a, LOCAL_BUS | 0x3f, SCODE_100);
}
static int ioctl_send_stream_packet(struct client *client, union ioctl_arg *arg)
{
struct fw_cdev_send_stream_packet *a = &arg->send_stream_packet;
struct fw_cdev_send_request request;
int dest;
if (a->speed > client->device->card->link_speed ||
a->length > 1024 << a->speed)
return -EIO;
if (a->tag > 3 || a->channel > 63 || a->sy > 15)
return -EINVAL;
dest = fw_stream_packet_destination_id(a->tag, a->channel, a->sy);
request.tcode = TCODE_STREAM_DATA;
request.length = a->length;
request.closure = a->closure;
request.data = a->data;
request.generation = a->generation;
return init_request(client, &request, dest, a->speed);
}
static int (* const ioctl_handlers[])(struct client *, union ioctl_arg *) = {
[0x00] = ioctl_get_info,
[0x01] = ioctl_send_request,
[0x02] = ioctl_allocate,
[0x03] = ioctl_deallocate,
[0x04] = ioctl_send_response,
[0x05] = ioctl_initiate_bus_reset,
[0x06] = ioctl_add_descriptor,
[0x07] = ioctl_remove_descriptor,
[0x08] = ioctl_create_iso_context,
[0x09] = ioctl_queue_iso,
[0x0a] = ioctl_start_iso,
[0x0b] = ioctl_stop_iso,
[0x0c] = ioctl_get_cycle_timer,
[0x0d] = ioctl_allocate_iso_resource,
[0x0e] = ioctl_deallocate_iso_resource,
[0x0f] = ioctl_allocate_iso_resource_once,
[0x10] = ioctl_deallocate_iso_resource_once,
[0x11] = ioctl_get_speed,
[0x12] = ioctl_send_broadcast_request,
[0x13] = ioctl_send_stream_packet,
[0x14] = ioctl_get_cycle_timer2,
};
static int dispatch_ioctl(struct client *client,
unsigned int cmd, void __user *arg)
{
union ioctl_arg buffer;
int ret;
if (fw_device_is_shutdown(client->device))
return -ENODEV;
if (_IOC_TYPE(cmd) != '#' ||
_IOC_NR(cmd) >= ARRAY_SIZE(ioctl_handlers) ||
_IOC_SIZE(cmd) > sizeof(buffer))
return -EINVAL;
if (_IOC_DIR(cmd) == _IOC_READ)
memset(&buffer, 0, _IOC_SIZE(cmd));
if (_IOC_DIR(cmd) & _IOC_WRITE)
if (copy_from_user(&buffer, arg, _IOC_SIZE(cmd)))
return -EFAULT;
ret = ioctl_handlers[_IOC_NR(cmd)](client, &buffer);
if (ret < 0)
return ret;
if (_IOC_DIR(cmd) & _IOC_READ)
if (copy_to_user(arg, &buffer, _IOC_SIZE(cmd)))
return -EFAULT;
return ret;
}
static long fw_device_op_ioctl(struct file *file,
unsigned int cmd, unsigned long arg)
{
return dispatch_ioctl(file->private_data, cmd, (void __user *)arg);
}
#ifdef CONFIG_COMPAT
static long fw_device_op_compat_ioctl(struct file *file,
unsigned int cmd, unsigned long arg)
{
return dispatch_ioctl(file->private_data, cmd, compat_ptr(arg));
}
#endif
static int fw_device_op_mmap(struct file *file, struct vm_area_struct *vma)
{
struct client *client = file->private_data;
enum dma_data_direction direction;
unsigned long size;
int page_count, ret;
if (fw_device_is_shutdown(client->device))
return -ENODEV;
/* FIXME: We could support multiple buffers, but we don't. */
if (client->buffer.pages != NULL)
return -EBUSY;
if (!(vma->vm_flags & VM_SHARED))
return -EINVAL;
if (vma->vm_start & ~PAGE_MASK)
return -EINVAL;
client->vm_start = vma->vm_start;
size = vma->vm_end - vma->vm_start;
page_count = size >> PAGE_SHIFT;
if (size & ~PAGE_MASK)
return -EINVAL;
if (vma->vm_flags & VM_WRITE)
direction = DMA_TO_DEVICE;
else
direction = DMA_FROM_DEVICE;
ret = fw_iso_buffer_init(&client->buffer, client->device->card,
page_count, direction);
if (ret < 0)
return ret;
ret = fw_iso_buffer_map(&client->buffer, vma);
if (ret < 0)
fw_iso_buffer_destroy(&client->buffer, client->device->card);
return ret;
}
static int shutdown_resource(int id, void *p, void *data)
{
struct client_resource *resource = p;
struct client *client = data;
resource->release(client, resource);
client_put(client);
return 0;
}
static int fw_device_op_release(struct inode *inode, struct file *file)
{
struct client *client = file->private_data;
struct event *event, *next_event;
mutex_lock(&client->device->client_list_mutex);
list_del(&client->link);
mutex_unlock(&client->device->client_list_mutex);
if (client->iso_context)
fw_iso_context_destroy(client->iso_context);
if (client->buffer.pages)
fw_iso_buffer_destroy(&client->buffer, client->device->card);
/* Freeze client->resource_idr and client->event_list */
spin_lock_irq(&client->lock);
client->in_shutdown = true;
spin_unlock_irq(&client->lock);
idr_for_each(&client->resource_idr, shutdown_resource, client);
idr_remove_all(&client->resource_idr);
idr_destroy(&client->resource_idr);
list_for_each_entry_safe(event, next_event, &client->event_list, link)
kfree(event);
client_put(client);
return 0;
}
static unsigned int fw_device_op_poll(struct file *file, poll_table * pt)
{
struct client *client = file->private_data;
unsigned int mask = 0;
poll_wait(file, &client->wait, pt);
if (fw_device_is_shutdown(client->device))
mask |= POLLHUP | POLLERR;
if (!list_empty(&client->event_list))
mask |= POLLIN | POLLRDNORM;
return mask;
}
const struct file_operations fw_device_ops = {
.owner = THIS_MODULE,
.llseek = no_llseek,
.open = fw_device_op_open,
.read = fw_device_op_read,
.unlocked_ioctl = fw_device_op_ioctl,
.mmap = fw_device_op_mmap,
.release = fw_device_op_release,
.poll = fw_device_op_poll,
#ifdef CONFIG_COMPAT
.compat_ioctl = fw_device_op_compat_ioctl,
#endif
};