From c9755e14a01987ada4063e8b4c50c2b6738d879e Mon Sep 17 00:00:00 2001 From: Stefan Richter Date: Mon, 24 Mar 2008 20:54:28 +0100 Subject: 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: Stefan Richter --- drivers/firewire/fw-device.c | 222 ++++++++++++++++++++++++++++++++++++------- 1 file changed, 188 insertions(+), 34 deletions(-) (limited to 'drivers/firewire/fw-device.c') diff --git a/drivers/firewire/fw-device.c b/drivers/firewire/fw-device.c index 20ac9a5afc3..75365cd0008 100644 --- a/drivers/firewire/fw-device.c +++ b/drivers/firewire/fw-device.c @@ -25,7 +25,7 @@ #include #include #include -#include +#include #include #include #include @@ -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, - "0x%06x\n", value); + 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; + + 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 snprintf(buf, PAGE_SIZE, "0x%08x%08x\n", - device->config_rom[3], device->config_rom[4]); + 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; -- cgit v1.2.3