linux/drivers/firewire/nosy.c
Stefan Richter c7b2a99c66 firewire: nosy: convert to unlocked ioctl
The required serialization of NOSY_IOC_START and NOSY_IOC_STOP is
already provided by the client_list_lock.

NOSY_IOC_FILTER does not really require serialization since accesses
to tcode_mask are atomic on any sane CPU architecture.  Nevertheless,
make it explicit that we want this to be atomic by means of
client_list_lock (which also surrounds the other tcode_mask access in
the IRQ handler).  While we are at it, change the type of tcode_mask to
u32 for consistency with the user API.

NOSY_IOC_GET_STATS does not require serialization against itself.  But
there is a bug here regarding concurrent updates of the two counters
by the IRQ handler.  Fix it by taking the client_list_lock in this ioctl
too.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-07-27 11:04:10 +02:00

685 lines
17 KiB
C

/*
* nosy - Snoop mode driver for TI PCILynx 1394 controllers
* Copyright (C) 2002-2007 Kristian Høgsberg
*
* 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/errno.h>
#include <linux/fs.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>
#include <linux/kernel.h>
#include <linux/miscdevice.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/poll.h>
#include <linux/sched.h> /* required for linux/wait.h */
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/timex.h>
#include <linux/uaccess.h>
#include <linux/wait.h>
#include <asm/atomic.h>
#include <asm/byteorder.h>
#include "nosy.h"
#include "nosy-user.h"
#define TCODE_PHY_PACKET 0x10
#define PCI_DEVICE_ID_TI_PCILYNX 0x8000
#define notify(s, args...) printk(KERN_NOTICE s, ## args)
#define error(s, args...) printk(KERN_ERR s, ## args)
#define debug(s, args...) printk(KERN_DEBUG s, ## args)
static char driver_name[] = KBUILD_MODNAME;
struct pcl_status {
unsigned int transfer_count : 13;
unsigned int reserved0 : 1;
unsigned int ack_type : 1;
unsigned int ack : 4;
unsigned int rcv_speed : 2;
unsigned int rcv_dma_channel : 6;
unsigned int packet_complete : 1;
unsigned int packet_error : 1;
unsigned int master_error : 1;
unsigned int iso_mode : 1;
unsigned int self_id : 1;
};
/* this is the physical layout of a PCL, its size is 128 bytes */
struct pcl {
u32 next;
u32 async_error_next;
u32 user_data;
struct pcl_status pcl_status;
u32 remaining_transfer_count;
u32 next_data_buffer;
struct {
u32 control;
u32 pointer;
} buffer[13] __attribute__ ((packed));
} __attribute__ ((packed));
struct packet {
unsigned int length;
char data[0];
};
struct packet_buffer {
char *data;
size_t capacity;
long total_packet_count, lost_packet_count;
atomic_t size;
struct packet *head, *tail;
wait_queue_head_t wait;
};
struct pcilynx {
struct pci_dev *pci_device;
unsigned char *registers;
struct pcl *rcv_start_pcl, *rcv_pcl;
u32 *rcv_buffer;
dma_addr_t rcv_start_pcl_bus, rcv_pcl_bus, rcv_buffer_bus;
spinlock_t client_list_lock;
struct list_head client_list;
struct miscdevice misc;
};
struct client {
struct pcilynx *lynx;
u32 tcode_mask;
struct packet_buffer buffer;
struct list_head link;
};
#define MAX_MINORS 64
static struct pcilynx *minors[MAX_MINORS];
static int
packet_buffer_init(struct packet_buffer *buffer, size_t capacity)
{
buffer->data = kmalloc(capacity, GFP_KERNEL);
if (buffer->data == NULL)
return -ENOMEM;
buffer->head = (struct packet *) buffer->data;
buffer->tail = (struct packet *) buffer->data;
buffer->capacity = capacity;
buffer->lost_packet_count = 0;
atomic_set(&buffer->size, 0);
init_waitqueue_head(&buffer->wait);
return 0;
}
static void
packet_buffer_destroy(struct packet_buffer *buffer)
{
kfree(buffer->data);
}
static int
packet_buffer_get(struct packet_buffer *buffer, void *data, size_t user_length)
{
size_t length;
char *end;
if (wait_event_interruptible(buffer->wait,
atomic_read(&buffer->size) > 0))
return -ERESTARTSYS;
/* FIXME: Check length <= user_length. */
end = buffer->data + buffer->capacity;
length = buffer->head->length;
if (&buffer->head->data[length] < end) {
if (copy_to_user(data, buffer->head->data, length))
return -EFAULT;
buffer->head = (struct packet *) &buffer->head->data[length];
} else {
size_t split = end - buffer->head->data;
if (copy_to_user(data, buffer->head->data, split))
return -EFAULT;
if (copy_to_user(data + split, buffer->data, length - split))
return -EFAULT;
buffer->head = (struct packet *) &buffer->data[length - split];
}
/*
* Decrease buffer->size as the last thing, since this is what
* keeps the interrupt from overwriting the packet we are
* retrieving from the buffer.
*/
atomic_sub(sizeof(struct packet) + length, &buffer->size);
return length;
}
static void
packet_buffer_put(struct packet_buffer *buffer, void *data, size_t length)
{
char *end;
buffer->total_packet_count++;
if (buffer->capacity <
atomic_read(&buffer->size) + sizeof(struct packet) + length) {
buffer->lost_packet_count++;
return;
}
end = buffer->data + buffer->capacity;
buffer->tail->length = length;
if (&buffer->tail->data[length] < end) {
memcpy(buffer->tail->data, data, length);
buffer->tail = (struct packet *) &buffer->tail->data[length];
} else {
size_t split = end - buffer->tail->data;
memcpy(buffer->tail->data, data, split);
memcpy(buffer->data, data + split, length - split);
buffer->tail = (struct packet *) &buffer->data[length - split];
}
/* Finally, adjust buffer size and wake up userspace reader. */
atomic_add(sizeof(struct packet) + length, &buffer->size);
wake_up_interruptible(&buffer->wait);
}
static inline void
reg_write(struct pcilynx *lynx, int offset, u32 data)
{
writel(data, lynx->registers + offset);
}
static inline u32
reg_read(struct pcilynx *lynx, int offset)
{
return readl(lynx->registers + offset);
}
static inline void
reg_set_bits(struct pcilynx *lynx, int offset, u32 mask)
{
reg_write(lynx, offset, (reg_read(lynx, offset) | mask));
}
/*
* Maybe the pcl programs could be set up to just append data instead
* of using a whole packet.
*/
static inline void
run_pcl(struct pcilynx *lynx, dma_addr_t pcl_bus,
int dmachan)
{
reg_write(lynx, DMA0_CURRENT_PCL + dmachan * 0x20, pcl_bus);
reg_write(lynx, DMA0_CHAN_CTRL + dmachan * 0x20,
DMA_CHAN_CTRL_ENABLE | DMA_CHAN_CTRL_LINK);
}
static int
set_phy_reg(struct pcilynx *lynx, int addr, int val)
{
if (addr > 15) {
debug("PHY register address %d out of range\n", addr);
return -1;
}
if (val > 0xff) {
debug("PHY register value %d out of range\n", val);
return -1;
}
reg_write(lynx, LINK_PHY, LINK_PHY_WRITE |
LINK_PHY_ADDR(addr) | LINK_PHY_WDATA(val));
return 0;
}
static void
nosy_start_snoop(struct client *client)
{
unsigned long flags;
spin_lock_irqsave(&client->lynx->client_list_lock, flags);
list_add_tail(&client->link, &client->lynx->client_list);
spin_unlock_irqrestore(&client->lynx->client_list_lock, flags);
}
static void
nosy_stop_snoop(struct client *client)
{
unsigned long flags;
spin_lock_irqsave(&client->lynx->client_list_lock, flags);
list_del(&client->link);
spin_unlock_irqrestore(&client->lynx->client_list_lock, flags);
}
static struct client *
nosy_add_client(struct pcilynx *lynx)
{
struct client *client;
client = kmalloc(sizeof *client, GFP_KERNEL);
client->tcode_mask = ~0;
client->lynx = lynx;
INIT_LIST_HEAD(&client->link);
if (packet_buffer_init(&client->buffer, 128 * 1024) < 0) {
kfree(client);
debug("Failed to allocate packet buffer\n");
return NULL;
}
return client;
}
static void
nosy_remove_client(struct client *client)
{
nosy_stop_snoop(client);
packet_buffer_destroy(&client->buffer);
kfree(client);
}
static int
nosy_open(struct inode *inode, struct file *file)
{
int minor = iminor(inode);
if (minor > MAX_MINORS || minors[minor] == NULL)
return -ENODEV;
file->private_data = nosy_add_client(minors[minor]);
if (file->private_data == NULL)
return -ENOMEM;
else
return 0;
}
static int
nosy_release(struct inode *inode, struct file *file)
{
nosy_remove_client(file->private_data);
return 0;
}
static unsigned int
nosy_poll(struct file *file, poll_table *pt)
{
struct client *client = file->private_data;
poll_wait(file, &client->buffer.wait, pt);
if (atomic_read(&client->buffer.size) > 0)
return POLLIN | POLLRDNORM;
else
return 0;
}
static ssize_t
nosy_read(struct file *file, char *buffer, size_t count, loff_t *offset)
{
struct client *client = file->private_data;
return packet_buffer_get(&client->buffer, buffer, count);
}
static long
nosy_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
{
struct client *client = file->private_data;
spinlock_t *client_list_lock = &client->lynx->client_list_lock;
struct nosy_stats stats;
switch (cmd) {
case NOSY_IOC_GET_STATS:
spin_lock_irq(client_list_lock);
stats.total_packet_count = client->buffer.total_packet_count;
stats.lost_packet_count = client->buffer.lost_packet_count;
spin_unlock_irq(client_list_lock);
if (copy_to_user((void *) arg, &stats, sizeof stats))
return -EFAULT;
else
return 0;
case NOSY_IOC_START:
nosy_start_snoop(client);
return 0;
case NOSY_IOC_STOP:
nosy_stop_snoop(client);
return 0;
case NOSY_IOC_FILTER:
spin_lock_irq(client_list_lock);
client->tcode_mask = arg;
spin_unlock_irq(client_list_lock);
return 0;
default:
return -EINVAL;
/* Flush buffer, configure filter. */
}
}
static const struct file_operations nosy_ops = {
.owner = THIS_MODULE,
.read = nosy_read,
.unlocked_ioctl = nosy_ioctl,
.poll = nosy_poll,
.open = nosy_open,
.release = nosy_release,
};
#define PHY_PACKET_SIZE 12 /* 1 payload, 1 inverse, 1 ack = 3 quadlets */
struct link_packet {
unsigned int priority : 4;
unsigned int tcode : 4;
unsigned int rt : 2;
unsigned int tlabel : 6;
unsigned int destination : 16;
};
static void
packet_handler(struct pcilynx *lynx)
{
unsigned long flags;
struct client *client;
u32 tcode_mask;
size_t length;
struct link_packet *packet;
struct timeval tv;
/* FIXME: Also report rcv_speed. */
length = lynx->rcv_pcl->pcl_status.transfer_count;
packet = (struct link_packet *) &lynx->rcv_buffer[1];
do_gettimeofday(&tv);
lynx->rcv_buffer[0] = tv.tv_usec;
if (length == PHY_PACKET_SIZE)
tcode_mask = 1 << TCODE_PHY_PACKET;
else
tcode_mask = 1 << packet->tcode;
spin_lock_irqsave(&lynx->client_list_lock, flags);
list_for_each_entry(client, &lynx->client_list, link)
if (client->tcode_mask & tcode_mask)
packet_buffer_put(&client->buffer,
lynx->rcv_buffer, length + 4);
spin_unlock_irqrestore(&lynx->client_list_lock, flags);
}
static void
bus_reset_handler(struct pcilynx *lynx)
{
unsigned long flags;
struct client *client;
struct timeval tv;
do_gettimeofday(&tv);
spin_lock_irqsave(&lynx->client_list_lock, flags);
list_for_each_entry(client, &lynx->client_list, link)
packet_buffer_put(&client->buffer, &tv.tv_usec, 4);
spin_unlock_irqrestore(&lynx->client_list_lock, flags);
}
static irqreturn_t
irq_handler(int irq, void *device)
{
struct pcilynx *lynx = device;
u32 pci_int_status;
pci_int_status = reg_read(lynx, PCI_INT_STATUS);
if ((pci_int_status & PCI_INT_INT_PEND) == 0)
/* Not our interrupt, bail out quickly. */
return IRQ_NONE;
if ((pci_int_status & PCI_INT_P1394_INT) != 0) {
u32 link_int_status;
link_int_status = reg_read(lynx, LINK_INT_STATUS);
reg_write(lynx, LINK_INT_STATUS, link_int_status);
if ((link_int_status & LINK_INT_PHY_BUSRESET) > 0)
bus_reset_handler(lynx);
}
/* Clear the PCI_INT_STATUS register only after clearing the
* LINK_INT_STATUS register; otherwise the PCI_INT_P1394 will
* be set again immediately. */
reg_write(lynx, PCI_INT_STATUS, pci_int_status);
if ((pci_int_status & PCI_INT_DMA0_HLT) > 0) {
packet_handler(lynx);
run_pcl(lynx, lynx->rcv_start_pcl_bus, 0);
}
return IRQ_HANDLED;
}
static void
remove_card(struct pci_dev *dev)
{
struct pcilynx *lynx;
lynx = pci_get_drvdata(dev);
if (!lynx)
return;
pci_set_drvdata(dev, NULL);
reg_write(lynx, PCI_INT_ENABLE, 0);
free_irq(lynx->pci_device->irq, lynx);
pci_free_consistent(lynx->pci_device, sizeof(struct pcl),
lynx->rcv_start_pcl, lynx->rcv_start_pcl_bus);
pci_free_consistent(lynx->pci_device, sizeof(struct pcl),
lynx->rcv_pcl, lynx->rcv_pcl_bus);
pci_free_consistent(lynx->pci_device, PAGE_SIZE,
lynx->rcv_buffer, lynx->rcv_buffer_bus);
iounmap(lynx->registers);
minors[lynx->misc.minor] = NULL;
misc_deregister(&lynx->misc);
kfree(lynx);
}
#define RCV_BUFFER_SIZE (16 * 1024)
static int __devinit
add_card(struct pci_dev *dev, const struct pci_device_id *unused)
{
struct pcilynx *lynx;
u32 p, end;
int i;
if (pci_set_dma_mask(dev, 0xffffffff)) {
error("DMA address limits not supported "
"for PCILynx hardware\n");
return -ENXIO;
}
if (pci_enable_device(dev)) {
error("Failed to enable PCILynx hardware\n");
return -ENXIO;
}
pci_set_master(dev);
lynx = kzalloc(sizeof *lynx, GFP_KERNEL);
if (lynx == NULL) {
error("Failed to allocate control structure memory\n");
return -ENOMEM;
}
lynx->pci_device = dev;
pci_set_drvdata(dev, lynx);
spin_lock_init(&lynx->client_list_lock);
INIT_LIST_HEAD(&lynx->client_list);
lynx->registers = ioremap_nocache(pci_resource_start(dev, 0),
PCILYNX_MAX_REGISTER);
lynx->rcv_start_pcl = pci_alloc_consistent(lynx->pci_device,
sizeof(struct pcl), &lynx->rcv_start_pcl_bus);
lynx->rcv_pcl = pci_alloc_consistent(lynx->pci_device,
sizeof(struct pcl), &lynx->rcv_pcl_bus);
lynx->rcv_buffer = pci_alloc_consistent(lynx->pci_device,
RCV_BUFFER_SIZE, &lynx->rcv_buffer_bus);
if (lynx->rcv_start_pcl == NULL ||
lynx->rcv_pcl == NULL ||
lynx->rcv_buffer == NULL) {
/* FIXME: do proper error handling. */
error("Failed to allocate receive buffer\n");
return -ENOMEM;
}
lynx->rcv_start_pcl->next = lynx->rcv_pcl_bus;
lynx->rcv_pcl->next = PCL_NEXT_INVALID;
lynx->rcv_pcl->async_error_next = PCL_NEXT_INVALID;
lynx->rcv_pcl->buffer[0].control =
PCL_CMD_RCV | PCL_BIGENDIAN | 2044;
lynx->rcv_pcl->buffer[0].pointer = lynx->rcv_buffer_bus + 4;
p = lynx->rcv_buffer_bus + 2048;
end = lynx->rcv_buffer_bus + RCV_BUFFER_SIZE;
for (i = 1; p < end; i++, p += 2048) {
lynx->rcv_pcl->buffer[i].control =
PCL_CMD_RCV | PCL_BIGENDIAN | 2048;
lynx->rcv_pcl->buffer[i].pointer = p;
}
lynx->rcv_pcl->buffer[i - 1].control |= PCL_LAST_BUFF;
reg_set_bits(lynx, MISC_CONTROL, MISC_CONTROL_SWRESET);
/* Fix buggy cards with autoboot pin not tied low: */
reg_write(lynx, DMA0_CHAN_CTRL, 0);
reg_write(lynx, DMA_GLOBAL_REGISTER, 0x00 << 24);
#if 0
/* now, looking for PHY register set */
if ((get_phy_reg(lynx, 2) & 0xe0) == 0xe0) {
lynx->phyic.reg_1394a = 1;
PRINT(KERN_INFO, lynx->id,
"found 1394a conform PHY (using extended register set)");
lynx->phyic.vendor = get_phy_vendorid(lynx);
lynx->phyic.product = get_phy_productid(lynx);
} else {
lynx->phyic.reg_1394a = 0;
PRINT(KERN_INFO, lynx->id, "found old 1394 PHY");
}
#endif
/* Setup the general receive FIFO max size. */
reg_write(lynx, FIFO_SIZES, 255);
reg_set_bits(lynx, PCI_INT_ENABLE, PCI_INT_DMA_ALL);
reg_write(lynx, LINK_INT_ENABLE,
LINK_INT_PHY_TIME_OUT | LINK_INT_PHY_REG_RCVD |
LINK_INT_PHY_BUSRESET | LINK_INT_IT_STUCK |
LINK_INT_AT_STUCK | LINK_INT_SNTRJ |
LINK_INT_TC_ERR | LINK_INT_GRF_OVER_FLOW |
LINK_INT_ITF_UNDER_FLOW | LINK_INT_ATF_UNDER_FLOW);
/* Disable the L flag in self ID packets. */
set_phy_reg(lynx, 4, 0);
/* Put this baby into snoop mode */
reg_set_bits(lynx, LINK_CONTROL, LINK_CONTROL_SNOOP_ENABLE);
run_pcl(lynx, lynx->rcv_start_pcl_bus, 0);
if (request_irq(dev->irq, irq_handler, IRQF_SHARED,
driver_name, lynx)) {
error("Failed to allocate shared interrupt %d\n", dev->irq);
return -EIO;
}
lynx->misc.parent = &dev->dev;
lynx->misc.minor = MISC_DYNAMIC_MINOR;
lynx->misc.name = "nosy";
lynx->misc.fops = &nosy_ops;
if (misc_register(&lynx->misc)) {
error("Failed to register misc char device\n");
return -ENOMEM;
}
minors[lynx->misc.minor] = lynx;
notify("Initialized PCILynx IEEE1394 card, irq=%d\n", dev->irq);
return 0;
}
static struct pci_device_id pci_table[] __devinitdata = {
{
.vendor = PCI_VENDOR_ID_TI,
.device = PCI_DEVICE_ID_TI_PCILYNX,
.subvendor = PCI_ANY_ID,
.subdevice = PCI_ANY_ID,
},
{ } /* Terminating entry */
};
static struct pci_driver lynx_pci_driver = {
.name = driver_name,
.id_table = pci_table,
.probe = add_card,
.remove = remove_card,
};
MODULE_AUTHOR("Kristian Hoegsberg");
MODULE_DESCRIPTION("Snoop mode driver for TI pcilynx 1394 controllers");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(pci, pci_table);
static int __init nosy_init(void)
{
return pci_register_driver(&lynx_pci_driver);
}
static void __exit nosy_cleanup(void)
{
pci_unregister_driver(&lynx_pci_driver);
notify("Unloaded %s.\n", driver_name);
}
module_init(nosy_init);
module_exit(nosy_cleanup);