UbiquitousOS
/
OpenCloudOS-Kernel
mirror of https://gitee.com/OpenCloudOS/OpenCloudOS-Kernel.git
11
0
Fork 0
Code Issues Projects Releases Wiki Activity

greybus: loopback: sort list of connections for masking purposes 

In user-space we specify a list of connections as a bit-mask with the
assumption that a list such is indexed as indicated below.

end0:3:3:1:1 = 1
end0:3:3:2:3 = 2
end0:3:3:3:4 = 4

Current code assigns bitmask ids based on the order of discovery, however
user-space has no idea what the order of discovery is. This patch sorts the
linked list of connections associated with the loopback driver and assigns
a bit-id based on the sorted list - not the order of discovery. This
change therefore enforces the end-users idea that end0:3:3:1:1 above is
always denoted by bit 1 - even if from the AP's perspective it was the last
entry discovered.

Signed-off-by: Bryan O'Donoghue <bryan.odonoghue@linaro.org>
Reviewed-by: Patrick Titiano <ptitiano@baylibre.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
This commit is contained in:
Bryan O'Donoghue 2015-09-14 10:48:46 +01:00 committed by Greg Kroah-Hartman
parent 4a655ad4c2
commit 5015115def
1 changed files with 46 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

48
drivers/staging/greybus/loopback.c
View File

@ -18,6 +18,7 @@
#include <linux/fs.h>
#include <linux/kfifo.h>
#include <linux/debugfs.h>
#include <linux/list_sort.h>
#include <asm/div64.h>
@ -843,6 +844,50 @@ static const struct file_operations gb_loopback_debugfs_dev_latency_ops = {
.release = single_release,
};
static int gb_loopback_bus_id_compare(void *priv, struct list_head *lha,
struct list_head *lhb)
{
struct gb_loopback *a = list_entry(lha, struct gb_loopback, entry);
struct gb_loopback *b = list_entry(lhb, struct gb_loopback, entry);
struct gb_connection *ca = a->connection;
struct gb_connection *cb = b->connection;
if (ca->bundle->intf->module->module_id <
cb->bundle->intf->module->module_id)
return -1;
if (cb->bundle->intf->module->module_id <
ca->bundle->intf->module->module_id)
return 1;
if (ca->bundle->intf->interface_id < cb->bundle->intf->interface_id)
return -1;
if (cb->bundle->intf->interface_id < ca->bundle->intf->interface_id)
return 1;
if (ca->bundle->id < cb->bundle->id)
return -1;
if (cb->bundle->id < ca->bundle->id)
return 1;
if (ca->intf_cport_id < cb->intf_cport_id)
return -1;
else if (cb->intf_cport_id < ca->intf_cport_id)
return 1;
return 0;
}
static void gb_loopback_insert_id(struct gb_loopback *gb)
{
struct gb_loopback *gb_list;
u32 new_lbid = 0;
/* perform an insertion sort */
list_add_tail(&gb->entry, &gb_dev.list);
list_sort(NULL, &gb_dev.list, gb_loopback_bus_id_compare);
list_for_each_entry(gb_list, &gb_dev.list, entry) {
gb_list->lbid = 1 << new_lbid;
new_lbid++;
}
}
#define DEBUGFS_NAMELEN 32
static int gb_loopback_connection_init(struct gb_connection *connection)
@ -908,14 +953,13 @@ static int gb_loopback_connection_init(struct gb_connection *connection)
/* Fork worker thread */
mutex_init(&gb->mutex);
gb->lbid = 1 << gb_dev.count;
gb->task = kthread_run(gb_loopback_fn, gb, "gb_loopback");
if (IS_ERR(gb->task)) {
retval = PTR_ERR(gb->task);
goto out_kfifo1;
}
list_add_tail(&gb->entry, &gb_dev.list);
gb_loopback_insert_id(gb);
gb_dev.count++;
mutex_unlock(&gb_dev.mutex);
return 0;