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Commit c9755e14 authored by Stefan Richter's avatar Stefan Richter
Browse files

firewire: reread config ROM when device reset the bus 



When a device changes its configuration ROM, it announces this with a
bus reset.  firewire-core has to check which node initiated a bus reset
and whether any unit directories went away or were added on this node.

Tested with an IOI FWB-IDE01AB which has its link-on bit set if bus
power is available but does not respond to ROM read requests if self
power is off.  This implements
  - recognition of the units if self power is switched on after fw-core
    gave up the initial attempt to read the config ROM,
  - shutdown of the units when self power is switched off.

Also tested with a second PC running Linux/ieee1394.  When the eth1394
driver is inserted and removed on that node, fw-core now notices the
addition and removal of the IPv4 unit on the ieee1394 node.

Signed-off-by: default avatarStefan Richter <stefanr@s5r6.in-berlin.de>
parent 1dadff71

drivers/firewire/fw-card.c

+1 −1
Original line number Diff line number Diff line
@@ -331,7 +331,7 @@ fw_card_bm_work(struct work_struct *work) 
		 */

		spin_unlock_irqrestore(&card->lock, flags);

		goto out;

	} else if (root_device->config_rom[2] & BIB_CMC) {

	} else if (root_device->cmc) {

		/*

		 * FIXME: I suppose we should set the cmstr bit in the

		 * STATE_CLEAR register of this node, as described in

drivers/firewire/fw-cdev.c

+10 −3
Original line number Diff line number Diff line
@@ -269,21 +269,28 @@ static int ioctl_get_info(struct client *client, void *buffer) 
{

	struct fw_cdev_get_info *get_info = buffer;

	struct fw_cdev_event_bus_reset bus_reset;

	unsigned long ret = 0;



	client->version = get_info->version;

	get_info->version = FW_CDEV_VERSION;



	down_read(&fw_device_rwsem);



	if (get_info->rom != 0) {

		void __user *uptr = u64_to_uptr(get_info->rom);

		size_t want = get_info->rom_length;

		size_t have = client->device->config_rom_length * 4;



		if (copy_to_user(uptr, client->device->config_rom,

				 min(want, have)))

			return -EFAULT;

		ret = copy_to_user(uptr, client->device->config_rom,

				   min(want, have));

	}

	get_info->rom_length = client->device->config_rom_length * 4;



	up_read(&fw_device_rwsem);



	if (ret != 0)

		return -EFAULT;



	client->bus_reset_closure = get_info->bus_reset_closure;

	if (get_info->bus_reset != 0) {

		void __user *uptr = u64_to_uptr(get_info->bus_reset);

drivers/firewire/fw-device.c

+188 −34
Original line number Diff line number Diff line
@@ -25,7 +25,7 @@ 
#include <linux/device.h>

#include <linux/delay.h>

#include <linux/idr.h>

#include <linux/rwsem.h>

#include <linux/string.h>

#include <asm/semaphore.h>

#include <asm/system.h>

#include <linux/ctype.h>
@@ -160,9 +160,9 @@ static void fw_device_release(struct device *dev) 
	 * Take the card lock so we don't set this to NULL while a

	 * FW_NODE_UPDATED callback is being handled.

	 */

	spin_lock_irqsave(&device->card->lock, flags);

	spin_lock_irqsave(&card->lock, flags);

	device->node->data = NULL;

	spin_unlock_irqrestore(&device->card->lock, flags);

	spin_unlock_irqrestore(&card->lock, flags);



	fw_node_put(device->node);

	kfree(device->config_rom);
@@ -195,7 +195,9 @@ show_immediate(struct device *dev, struct device_attribute *dattr, char *buf) 
		container_of(dattr, struct config_rom_attribute, attr);

	struct fw_csr_iterator ci;

	u32 *dir;

	int key, value;

	int key, value, ret = -ENOENT;



	down_read(&fw_device_rwsem);



	if (is_fw_unit(dev))

		dir = fw_unit(dev)->directory;
@@ -204,11 +206,15 @@ show_immediate(struct device *dev, struct device_attribute *dattr, char *buf) 


	fw_csr_iterator_init(&ci, dir);

	while (fw_csr_iterator_next(&ci, &key, &value))

		if (attr->key == key)

			return snprintf(buf, buf ? PAGE_SIZE : 0,

		if (attr->key == key) {

			ret = snprintf(buf, buf ? PAGE_SIZE : 0,

				       "0x%06x\n", value);

			break;

		}



	up_read(&fw_device_rwsem);



	return -ENOENT;

	return ret;

}



#define IMMEDIATE_ATTR(name, key)				\
@@ -221,9 +227,11 @@ show_text_leaf(struct device *dev, struct device_attribute *dattr, char *buf) 
		container_of(dattr, struct config_rom_attribute, attr);

	struct fw_csr_iterator ci;

	u32 *dir, *block = NULL, *p, *end;

	int length, key, value, last_key = 0;

	int length, key, value, last_key = 0, ret = -ENOENT;

	char *b;



	down_read(&fw_device_rwsem);



	if (is_fw_unit(dev))

		dir = fw_unit(dev)->directory;

	else
@@ -238,18 +246,20 @@ show_text_leaf(struct device *dev, struct device_attribute *dattr, char *buf) 
	}



	if (block == NULL)

		return -ENOENT;

		goto out;



	length = min(block[0] >> 16, 256U);

	if (length < 3)

		return -ENOENT;

		goto out;



	if (block[1] != 0 || block[2] != 0)

		/* Unknown encoding. */

		return -ENOENT;

		goto out;



	if (buf == NULL)

		return length * 4;

	if (buf == NULL) {

		ret = length * 4;

		goto out;

	}



	b = buf;

	end = &block[length + 1];
@@ -259,8 +269,11 @@ show_text_leaf(struct device *dev, struct device_attribute *dattr, char *buf) 
	/* Strip trailing whitespace and add newline. */

	while (b--, (isspace(*b) || *b == '\0') && b > buf);

	strcpy(b + 1, "\n");

	ret = b + 2 - buf;

 out:

	up_read(&fw_device_rwsem);



	return b + 2 - buf;

	return ret;

}



#define TEXT_LEAF_ATTR(name, key)				\
@@ -337,19 +350,28 @@ static ssize_t 
config_rom_show(struct device *dev, struct device_attribute *attr, char *buf)

{

	struct fw_device *device = fw_device(dev);

	size_t length;



	memcpy(buf, device->config_rom, device->config_rom_length * 4);

	down_read(&fw_device_rwsem);

	length = device->config_rom_length * 4;

	memcpy(buf, device->config_rom, length);

	up_read(&fw_device_rwsem);



	return device->config_rom_length * 4;

	return length;

}



static ssize_t

guid_show(struct device *dev, struct device_attribute *attr, char *buf)

{

	struct fw_device *device = fw_device(dev);

	int ret;



	return snprintf(buf, PAGE_SIZE, "0x%08x%08x\n",

	down_read(&fw_device_rwsem);

	ret = snprintf(buf, PAGE_SIZE, "0x%08x%08x\n",

		       device->config_rom[3], device->config_rom[4]);

	up_read(&fw_device_rwsem);



	return ret;

}



static struct device_attribute fw_device_attributes[] = {
@@ -412,7 +434,7 @@ read_rom(struct fw_device *device, int generation, int index, u32 *data) 
 */

static int read_bus_info_block(struct fw_device *device, int generation)

{

	u32 *rom, *stack;

	u32 *rom, *stack, *old_rom, *new_rom;

	u32 sp, key;

	int i, end, length, ret = -1;
@@ -527,12 +549,19 @@ static int read_bus_info_block(struct fw_device *device, int generation) 
			length = i;

	}



	device->config_rom = kmalloc(length * 4, GFP_KERNEL);

	if (device->config_rom == NULL)

	old_rom = device->config_rom;

	new_rom = kmemdup(rom, length * 4, GFP_KERNEL);

	if (new_rom == NULL)

		goto out;

	memcpy(device->config_rom, rom, length * 4);



	down_write(&fw_device_rwsem);

	device->config_rom = new_rom;

	device->config_rom_length = length;

	up_write(&fw_device_rwsem);



	kfree(old_rom);

	ret = 0;

	device->cmc = rom[2] & 1 << 30;

 out:

	kfree(rom);
@@ -605,7 +634,14 @@ static int shutdown_unit(struct device *device, void *data) 
	return 0;

}



static DECLARE_RWSEM(idr_rwsem);

/*

 * fw_device_rwsem acts as dual purpose mutex:

 *   - serializes accesses to fw_device_idr,

 *   - serializes accesses to fw_device.config_rom/.config_rom_length and

 *     fw_unit.directory, unless those accesses happen at safe occasions

 */

DECLARE_RWSEM(fw_device_rwsem);



static DEFINE_IDR(fw_device_idr);

int fw_cdev_major;
@@ -613,11 +649,11 @@ struct fw_device *fw_device_get_by_devt(dev_t devt) 
{

	struct fw_device *device;



	down_read(&idr_rwsem);

	down_read(&fw_device_rwsem);

	device = idr_find(&fw_device_idr, MINOR(devt));

	if (device)

		fw_device_get(device);

	up_read(&idr_rwsem);

	up_read(&fw_device_rwsem);



	return device;

}
@@ -632,9 +668,9 @@ static void fw_device_shutdown(struct work_struct *work) 
	device_for_each_child(&device->device, NULL, shutdown_unit);

	device_unregister(&device->device);



	down_write(&idr_rwsem);

	down_write(&fw_device_rwsem);

	idr_remove(&fw_device_idr, minor);

	up_write(&idr_rwsem);

	up_write(&fw_device_rwsem);

	fw_device_put(device);

}
@@ -687,10 +723,10 @@ static void fw_device_init(struct work_struct *work) 
	err = -ENOMEM;



	fw_device_get(device);

	down_write(&idr_rwsem);

	down_write(&fw_device_rwsem);

	if (idr_pre_get(&fw_device_idr, GFP_KERNEL))

		err = idr_get_new(&fw_device_idr, device, &minor);

	up_write(&idr_rwsem);

	up_write(&fw_device_rwsem);



	if (err < 0)

		goto error;
@@ -724,7 +760,7 @@ static void fw_device_init(struct work_struct *work) 
	if (atomic_cmpxchg(&device->state,

		    FW_DEVICE_INITIALIZING,

		    FW_DEVICE_RUNNING) == FW_DEVICE_SHUTDOWN) {

		fw_device_shutdown(&device->work.work);

		fw_device_shutdown(work);

	} else {

		if (device->config_rom_retries)

			fw_notify("created device %s: GUID %08x%08x, S%d00, "
@@ -738,6 +774,7 @@ static void fw_device_init(struct work_struct *work) 
				  device->device.bus_id,

				  device->config_rom[3], device->config_rom[4],

				  1 << device->max_speed);

		device->config_rom_retries = 0;

	}



	/*
@@ -752,9 +789,9 @@ static void fw_device_init(struct work_struct *work) 
	return;



 error_with_cdev:

	down_write(&idr_rwsem);

	down_write(&fw_device_rwsem);

	idr_remove(&fw_device_idr, minor);

	up_write(&idr_rwsem);

	up_write(&fw_device_rwsem);

 error:

	fw_device_put(device);		/* fw_device_idr's reference */
@@ -784,6 +821,106 @@ static void fw_device_update(struct work_struct *work) 
	device_for_each_child(&device->device, NULL, update_unit);

}



enum {

	REREAD_BIB_ERROR,

	REREAD_BIB_GONE,

	REREAD_BIB_UNCHANGED,

	REREAD_BIB_CHANGED,

};



/* Reread and compare bus info block and header of root directory */

static int reread_bus_info_block(struct fw_device *device, int generation)

{

	u32 q;

	int i;



	for (i = 0; i < 6; i++) {

		if (read_rom(device, generation, i, &q) != RCODE_COMPLETE)

			return REREAD_BIB_ERROR;



		if (i == 0 && q == 0)

			return REREAD_BIB_GONE;



		if (i > device->config_rom_length || q != device->config_rom[i])

			return REREAD_BIB_CHANGED;

	}



	return REREAD_BIB_UNCHANGED;

}



static void fw_device_refresh(struct work_struct *work)

{

	struct fw_device *device =

		container_of(work, struct fw_device, work.work);

	struct fw_card *card = device->card;

	int node_id = device->node_id;



	switch (reread_bus_info_block(device, device->generation)) {

	case REREAD_BIB_ERROR:

		if (device->config_rom_retries < MAX_RETRIES / 2 &&

		    atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {

			device->config_rom_retries++;

			schedule_delayed_work(&device->work, RETRY_DELAY / 2);



			return;

		}

		goto give_up;



	case REREAD_BIB_GONE:

		goto gone;



	case REREAD_BIB_UNCHANGED:

		if (atomic_cmpxchg(&device->state,

			    FW_DEVICE_INITIALIZING,

			    FW_DEVICE_RUNNING) == FW_DEVICE_SHUTDOWN)

			goto gone;



		fw_device_update(work);

		device->config_rom_retries = 0;

		goto out;



	case REREAD_BIB_CHANGED:

		break;

	}



	/*

	 * Something changed.  We keep things simple and don't investigate

	 * further.  We just destroy all previous units and create new ones.

	 */

	device_for_each_child(&device->device, NULL, shutdown_unit);



	if (read_bus_info_block(device, device->generation) < 0) {

		if (device->config_rom_retries < MAX_RETRIES &&

		    atomic_read(&device->state) == FW_DEVICE_INITIALIZING) {

			device->config_rom_retries++;

			schedule_delayed_work(&device->work, RETRY_DELAY);



			return;

		}

		goto give_up;

	}



	create_units(device);



	if (atomic_cmpxchg(&device->state,

		    FW_DEVICE_INITIALIZING,

		    FW_DEVICE_RUNNING) == FW_DEVICE_SHUTDOWN)

		goto gone;



	fw_notify("refreshed device %s\n", device->device.bus_id);

	device->config_rom_retries = 0;

	goto out;



 give_up:

	fw_notify("giving up on refresh of device %s\n", device->device.bus_id);

 gone:

	atomic_set(&device->state, FW_DEVICE_SHUTDOWN);

	fw_device_shutdown(work);

 out:

	if (node_id == card->root_node->node_id)

		schedule_delayed_work(&card->work, 0);

}



void fw_node_event(struct fw_card *card, struct fw_node *node, int event)

{

	struct fw_device *device;
@@ -793,7 +930,7 @@ void fw_node_event(struct fw_card *card, struct fw_node *node, int event) 
	case FW_NODE_LINK_ON:

		if (!node->link_on)

			break;



 create:

		device = kzalloc(sizeof(*device), GFP_ATOMIC);

		if (device == NULL)

			break;
@@ -832,6 +969,23 @@ void fw_node_event(struct fw_card *card, struct fw_node *node, int event) 
		schedule_delayed_work(&device->work, INITIAL_DELAY);

		break;



	case FW_NODE_INITIATED_RESET:

		device = node->data;

		if (device == NULL)

			goto create;



		device->node_id = node->node_id;

		smp_wmb();  /* update node_id before generation */

		device->generation = card->generation;

		if (atomic_cmpxchg(&device->state,

			    FW_DEVICE_RUNNING,

			    FW_DEVICE_INITIALIZING) == FW_DEVICE_RUNNING) {

			PREPARE_DELAYED_WORK(&device->work, fw_device_refresh);

			schedule_delayed_work(&device->work,

				node == card->local_node ? 0 : INITIAL_DELAY);

		}

		break;



	case FW_NODE_UPDATED:

		if (!node->link_on || node->data == NULL)

			break;

drivers/firewire/fw-device.h

+11 −0
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ 


#include <linux/fs.h>

#include <linux/cdev.h>

#include <linux/rwsem.h>

#include <asm/atomic.h>



enum fw_device_state {
@@ -46,6 +47,11 @@ struct fw_attribute_group { 
 * fw_device.node_id is guaranteed to be current too.

 *

 * The same applies to fw_device.card->node_id vs. fw_device.generation.

 *

 * fw_device.config_rom and fw_device.config_rom_length may be accessed during

 * the lifetime of any fw_unit belonging to the fw_device, before device_del()

 * was called on the last fw_unit.  Alternatively, they may be accessed while

 * holding fw_device_rwsem.

 */

struct fw_device {

	atomic_t state;
@@ -53,6 +59,7 @@ struct fw_device { 
	int node_id;

	int generation;

	unsigned max_speed;

	bool cmc;

	struct fw_card *card;

	struct device device;

	struct list_head link;
@@ -92,8 +99,12 @@ int fw_device_enable_phys_dma(struct fw_device *device); 
void fw_device_cdev_update(struct fw_device *device);

void fw_device_cdev_remove(struct fw_device *device);



extern struct rw_semaphore fw_device_rwsem;

extern int fw_cdev_major;



/*

 * fw_unit.directory must not be accessed after device_del(&fw_unit.device).

 */

struct fw_unit {

	struct device device;

	u32 *directory;

drivers/firewire/fw-sbp2.c

+4 −4
Original line number Diff line number Diff line
@@ -153,6 +153,7 @@ struct sbp2_target { 
	struct list_head lu_list;



	u64 management_agent_address;

	u64 guid;

	int directory_id;

	int node_id;

	int address_high;
@@ -1114,6 +1115,7 @@ static int sbp2_probe(struct device *dev) 
	kref_init(&tgt->kref);

	INIT_LIST_HEAD(&tgt->lu_list);

	tgt->bus_id = unit->device.bus_id;

	tgt->guid = (u64)device->config_rom[3] << 32 | device->config_rom[4];



	if (fw_device_enable_phys_dma(device) < 0)

		goto fail_shost_put;
@@ -1571,16 +1573,14 @@ sbp2_sysfs_ieee1394_id_show(struct device *dev, struct device_attribute *attr, 
{

	struct scsi_device *sdev = to_scsi_device(dev);

	struct sbp2_logical_unit *lu;

	struct fw_device *device;



	if (!sdev)

		return 0;



	lu = sdev->hostdata;

	device = fw_device(lu->tgt->unit->device.parent);



	return sprintf(buf, "%08x%08x:%06x:%04x\n",

			device->config_rom[3], device->config_rom[4],

	return sprintf(buf, "%016llx:%06x:%04x\n",

			(unsigned long long)lu->tgt->guid,

			lu->tgt->directory_id, lu->lun);

}