From 7356a764cd76e155014c226ccb157219be918891 Mon Sep 17 00:00:00 2001 From: Jiri Benc Date: Fri, 12 Apr 2013 00:56:15 +0000 Subject: 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 Acked-by: Richard Cochran Signed-off-by: David S. Miller --- drivers/ptp/ptp_clock.c | 38 +++++++++++++------------------------- 1 file changed, 13 insertions(+), 25 deletions(-) (limited to 'drivers/ptp/ptp_clock.c') 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 +#include #include #include #include @@ -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; -- cgit