Commit 6b150fab authored by Ben Collins's avatar Ben Collins

[IEEE1394]: Rework highlevel list locking to avoid blocking under spinlocks.

parent 3d315130
......@@ -39,8 +39,12 @@ struct hl_host_info {
static LIST_HEAD(hl_drivers);
static rwlock_t hl_drivers_lock = RW_LOCK_UNLOCKED;
static DECLARE_RWSEM(hl_drivers_sem);
static LIST_HEAD(hl_irqs);
static rwlock_t hl_irqs_lock = RW_LOCK_UNLOCKED;
static LIST_HEAD(addr_space);
static rwlock_t addr_space_lock = RW_LOCK_UNLOCKED;
/* addr_space list will have zero and max already included as bounds */
......@@ -238,20 +242,22 @@ static int highlevel_for_each_host_reg(struct hpsb_host *host, void *__data)
void hpsb_register_highlevel(struct hpsb_highlevel *hl)
{
unsigned long flags;
INIT_LIST_HEAD(&hl->addr_list);
INIT_LIST_HEAD(&hl->host_info_list);
rwlock_init(&hl->host_info_lock);
write_lock_irqsave(&hl_drivers_lock, flags);
down_write(&hl_drivers_sem);
list_add_tail(&hl->hl_list, &hl_drivers);
write_unlock_irqrestore(&hl_drivers_lock, flags);
up_write(&hl_drivers_sem);
if (hl->add_host)
nodemgr_for_each_host(hl, highlevel_for_each_host_reg);
write_lock(&hl_irqs_lock);
list_add_tail(&hl->irq_list, &hl_irqs);
write_unlock(&hl_irqs_lock);
return;
}
......@@ -279,9 +285,13 @@ void hpsb_unregister_highlevel(struct hpsb_highlevel *hl)
}
write_unlock_irqrestore(&addr_space_lock, flags);
write_lock_irqsave(&hl_drivers_lock, flags);
write_lock(&hl_irqs_lock);
list_del(&hl->irq_list);
write_unlock(&hl_irqs_lock);
down_write(&hl_drivers_sem);
list_del(&hl->hl_list);
write_unlock_irqrestore(&hl_drivers_lock, flags);
up_write(&hl_drivers_sem);
if (hl->remove_host)
nodemgr_for_each_host(hl, highlevel_for_each_host_unreg);
......@@ -395,38 +405,31 @@ void hpsb_unlisten_channel(struct hpsb_highlevel *hl, struct hpsb_host *host,
void highlevel_add_host(struct hpsb_host *host)
{
struct list_head *entry;
struct hpsb_highlevel *hl;
init_hpsb_highlevel(host);
read_lock(&hl_drivers_lock);
list_for_each(entry, &hl_drivers) {
hl = list_entry(entry, struct hpsb_highlevel, hl_list);
down_read(&hl_drivers_sem);
list_for_each_entry(hl, &hl_drivers, hl_list) {
if (hl->add_host)
hl->add_host(host);
}
read_unlock(&hl_drivers_lock);
up_read(&hl_drivers_sem);
}
void highlevel_remove_host(struct hpsb_host *host)
{
struct list_head *entry;
struct hpsb_highlevel *hl;
struct list_head *lh, *next;
struct hpsb_address_serve *as;
unsigned long flags;
read_lock(&hl_drivers_lock);
list_for_each(entry, &hl_drivers) {
hl = list_entry(entry, struct hpsb_highlevel, hl_list);
down_read(&hl_drivers_sem);
list_for_each_entry(hl, &hl_drivers, hl_list) {
if (hl->remove_host) {
hl->remove_host(host);
hpsb_destroy_hostinfo(hl, host);
}
}
read_unlock(&hl_drivers_lock);
up_read(&hl_drivers_sem);
/* Free up 1394 address space left behind by high level drivers. */
write_lock_irqsave(&addr_space_lock, flags);
......@@ -442,58 +445,42 @@ void highlevel_remove_host(struct hpsb_host *host)
void highlevel_host_reset(struct hpsb_host *host)
{
struct list_head *entry;
struct hpsb_highlevel *hl;
read_lock(&hl_drivers_lock);
list_for_each(entry, &hl_drivers) {
hl = list_entry(entry, struct hpsb_highlevel, hl_list);
read_lock(&hl_irqs_lock);
list_for_each_entry(hl, &hl_irqs, hl_list) {
if (hl->host_reset)
hl->host_reset(host);
}
read_unlock(&hl_drivers_lock);
read_unlock(&hl_irqs_lock);
}
void highlevel_iso_receive(struct hpsb_host *host, void *data,
size_t length)
void highlevel_iso_receive(struct hpsb_host *host, void *data, size_t length)
{
struct list_head *entry;
struct hpsb_highlevel *hl;
int channel = (((quadlet_t *)data)[0] >> 8) & 0x3f;
read_lock(&hl_drivers_lock);
entry = hl_drivers.next;
while (entry != &hl_drivers) {
hl = list_entry(entry, struct hpsb_highlevel, hl_list);
if (hl->iso_receive) {
read_lock(&hl_irqs_lock);
list_for_each_entry(hl, &hl_irqs, irq_list) {
if (hl->iso_receive)
hl->iso_receive(host, channel, data, length);
}
entry = entry->next;
}
read_unlock(&hl_drivers_lock);
read_unlock(&hl_irqs_lock);
}
void highlevel_fcp_request(struct hpsb_host *host, int nodeid, int direction,
void *data, size_t length)
{
struct list_head *entry;
struct hpsb_highlevel *hl;
int cts = ((quadlet_t *)data)[0] >> 4;
read_lock(&hl_drivers_lock);
entry = hl_drivers.next;
while (entry != &hl_drivers) {
hl = list_entry(entry, struct hpsb_highlevel, hl_list);
if (hl->fcp_request) {
read_lock(&hl_irqs_lock);
list_for_each_entry(hl, &hl_irqs, irq_list) {
if (hl->fcp_request)
hl->fcp_request(host, nodeid, direction, cts, data,
length);
}
entry = entry->next;
}
read_unlock(&hl_drivers_lock);
read_unlock(&hl_irqs_lock);
}
int highlevel_read(struct hpsb_host *host, int nodeid, void *data,
......
......@@ -38,9 +38,9 @@ struct hpsb_highlevel {
* hpsb_unregister_highlevel once for each host. */
void (*remove_host) (struct hpsb_host *host);
/* Host experienced bus reset with possible configuration changes. Note
* that this one may occur during interrupt/bottom half handling. You
* can not expect to be able to do stock hpsb_reads. */
/* Host experienced bus reset with possible configuration changes.
* Note that this one may occur during interrupt/bottom half handling.
* You can not expect to be able to do stock hpsb_reads. */
void (*host_reset) (struct hpsb_host *host);
/* An isochronous packet was received. Channel contains the channel
......@@ -52,13 +52,14 @@ struct hpsb_highlevel {
/* A write request was received on either the FCP_COMMAND (direction =
* 0) or the FCP_RESPONSE (direction = 1) register. The cts arg
* contains the cts field (first byte of data).
*/
* contains the cts field (first byte of data). */
void (*fcp_request) (struct hpsb_host *host, int nodeid, int direction,
int cts, u8 *data, size_t length);
/* These are initialized by the subsystem when the
* hpsb_higlevel is registered. */
struct list_head hl_list;
struct list_head irq_list;
struct list_head addr_list;
struct list_head host_info_list;
......
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