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authorJiri Benc <jbenc@redhat.com>2013-04-12 00:56:15 +0000
committerDavid S. Miller <davem@davemloft.net>2013-04-12 18:22:45 -0400
commit7356a764cd76e155014c226ccb157219be918891 (patch)
tree3cdc441f494782192ebdc2a23d5930224ca3743c /drivers/ptp
parentd6a4a10411764cf1c3a5dad4f06c5ebe5194488b (diff)
downloadlinux-7356a764cd76e155014c226ccb157219be918891.tar.bz2
ptp: dynamic allocation of PHC char devices
As network adapters supporting PTP are becoming more common, machines with many NICs suddenly have many PHCs, too. The current limit of eight /dev/ptp* char devices (and thus, 8 network interfaces with PHC) is insufficient. Let the ptp driver allocate the char devices dynamically. Tested with 28 PHCs, removing and re-adding some of them. Thanks to Ben Hutchings for advice leading to simpler and cleaner patch. Signed-off-by: Jiri Benc <jbenc@redhat.com> Acked-by: Richard Cochran <richardcochran@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/ptp')
-rw-r--r--drivers/ptp/ptp_clock.c38
1 files changed, 13 insertions, 25 deletions
diff --git a/drivers/ptp/ptp_clock.c b/drivers/ptp/ptp_clock.c
index 79f4bce061bd..4a8c388364ca 100644
--- a/drivers/ptp/ptp_clock.c
+++ b/drivers/ptp/ptp_clock.c
@@ -17,7 +17,7 @@
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
-#include <linux/bitops.h>
+#include <linux/idr.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/init.h>
@@ -32,7 +32,6 @@
#include "ptp_private.h"
#define PTP_MAX_ALARMS 4
-#define PTP_MAX_CLOCKS 8
#define PTP_PPS_DEFAULTS (PPS_CAPTUREASSERT | PPS_OFFSETASSERT)
#define PTP_PPS_EVENT PPS_CAPTUREASSERT
#define PTP_PPS_MODE (PTP_PPS_DEFAULTS | PPS_CANWAIT | PPS_TSFMT_TSPEC)
@@ -42,8 +41,7 @@
static dev_t ptp_devt;
static struct class *ptp_class;
-static DECLARE_BITMAP(ptp_clocks_map, PTP_MAX_CLOCKS);
-static DEFINE_MUTEX(ptp_clocks_mutex); /* protects 'ptp_clocks_map' */
+static DEFINE_IDA(ptp_clocks_map);
/* time stamp event queue operations */
@@ -171,12 +169,7 @@ static void delete_ptp_clock(struct posix_clock *pc)
struct ptp_clock *ptp = container_of(pc, struct ptp_clock, clock);
mutex_destroy(&ptp->tsevq_mux);
-
- /* Remove the clock from the bit map. */
- mutex_lock(&ptp_clocks_mutex);
- clear_bit(ptp->index, ptp_clocks_map);
- mutex_unlock(&ptp_clocks_mutex);
-
+ ida_simple_remove(&ptp_clocks_map, ptp->index);
kfree(ptp);
}
@@ -191,21 +184,18 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
if (info->n_alarm > PTP_MAX_ALARMS)
return ERR_PTR(-EINVAL);
- /* Find a free clock slot and reserve it. */
- err = -EBUSY;
- mutex_lock(&ptp_clocks_mutex);
- index = find_first_zero_bit(ptp_clocks_map, PTP_MAX_CLOCKS);
- if (index < PTP_MAX_CLOCKS)
- set_bit(index, ptp_clocks_map);
- else
- goto no_slot;
-
/* Initialize a clock structure. */
err = -ENOMEM;
ptp = kzalloc(sizeof(struct ptp_clock), GFP_KERNEL);
if (ptp == NULL)
goto no_memory;
+ index = ida_simple_get(&ptp_clocks_map, 0, MINORMASK + 1, GFP_KERNEL);
+ if (index < 0) {
+ err = index;
+ goto no_slot;
+ }
+
ptp->clock.ops = ptp_clock_ops;
ptp->clock.release = delete_ptp_clock;
ptp->info = info;
@@ -248,7 +238,6 @@ struct ptp_clock *ptp_clock_register(struct ptp_clock_info *info,
goto no_clock;
}
- mutex_unlock(&ptp_clocks_mutex);
return ptp;
no_clock:
@@ -260,11 +249,9 @@ no_sysfs:
device_destroy(ptp_class, ptp->devid);
no_device:
mutex_destroy(&ptp->tsevq_mux);
+no_slot:
kfree(ptp);
no_memory:
- clear_bit(index, ptp_clocks_map);
-no_slot:
- mutex_unlock(&ptp_clocks_mutex);
return ERR_PTR(err);
}
EXPORT_SYMBOL(ptp_clock_register);
@@ -323,7 +310,8 @@ EXPORT_SYMBOL(ptp_clock_index);
static void __exit ptp_exit(void)
{
class_destroy(ptp_class);
- unregister_chrdev_region(ptp_devt, PTP_MAX_CLOCKS);
+ unregister_chrdev_region(ptp_devt, MINORMASK + 1);
+ ida_destroy(&ptp_clocks_map);
}
static int __init ptp_init(void)
@@ -336,7 +324,7 @@ static int __init ptp_init(void)
return PTR_ERR(ptp_class);
}
- err = alloc_chrdev_region(&ptp_devt, 0, PTP_MAX_CLOCKS, "ptp");
+ err = alloc_chrdev_region(&ptp_devt, 0, MINORMASK + 1, "ptp");
if (err < 0) {
pr_err("ptp: failed to allocate device region\n");
goto no_region;