[PATCH 6/8] IB/hns: Replace counting semaphore event_sem with wait condition

From: Binoy Jayan
Date: Mon Oct 17 2016 - 12:32:39 EST


Counting semaphores are going away in the future, so replace the semaphore
hns_roce_cmdq::event_sem with an open-coded implementation.

Signed-off-by: Binoy Jayan <binoy.jayan@xxxxxxxxxx>
---
drivers/infiniband/hw/hns/hns_roce_cmd.c | 16 ++++++++++++----
drivers/infiniband/hw/hns/hns_roce_device.h | 3 ++-
include/rdma/ib_sa.h | 5 +++++
3 files changed, 19 insertions(+), 5 deletions(-)

diff --git a/drivers/infiniband/hw/hns/hns_roce_cmd.c b/drivers/infiniband/hw/hns/hns_roce_cmd.c
index 1421fdb..3e76717 100644
--- a/drivers/infiniband/hw/hns/hns_roce_cmd.c
+++ b/drivers/infiniband/hw/hns/hns_roce_cmd.c
@@ -248,10 +248,14 @@ static int hns_roce_cmd_mbox_wait(struct hns_roce_dev *hr_dev, u64 in_param,
{
int ret = 0;

- down(&hr_dev->cmd.event_sem);
+ wait_event(hr_dev->cmd.event_sem.wq,
+ atomic_add_unless(&hr_dev->cmd.event_sem.count, -1, 0));
+
ret = __hns_roce_cmd_mbox_wait(hr_dev, in_param, out_param,
in_modifier, op_modifier, op, timeout);
- up(&hr_dev->cmd.event_sem);
+
+ if (atomic_inc_return(&hr_dev->cmd.event_sem.count) == 1)
+ wake_up(&hr_dev->cmd.event_sem.wq);

return ret;
}
@@ -313,7 +317,9 @@ int hns_roce_cmd_use_events(struct hns_roce_dev *hr_dev)
hr_cmd->context[hr_cmd->max_cmds - 1].next = -1;
hr_cmd->free_head = 0;

- sema_init(&hr_cmd->event_sem, hr_cmd->max_cmds);
+ init_waitqueue_head(&hr_cmd->event_sem.wq);
+ atomic_set(&hr_cmd->event_sem.count, hr_cmd->max_cmds);
+
spin_lock_init(&hr_cmd->context_lock);

hr_cmd->token_mask = CMD_TOKEN_MASK;
@@ -332,7 +338,9 @@ void hns_roce_cmd_use_polling(struct hns_roce_dev *hr_dev)
hr_cmd->use_events = 0;

for (i = 0; i < hr_cmd->max_cmds; ++i)
- down(&hr_cmd->event_sem);
+ wait_event(hr_cmd->event_sem.wq,
+ atomic_add_unless(
+ &hr_dev->cmd.event_sem.count, -1, 0));

kfree(hr_cmd->context);
mutex_unlock(&hr_cmd->poll_mutex);
diff --git a/drivers/infiniband/hw/hns/hns_roce_device.h b/drivers/infiniband/hw/hns/hns_roce_device.h
index 2afe075..6aed04a 100644
--- a/drivers/infiniband/hw/hns/hns_roce_device.h
+++ b/drivers/infiniband/hw/hns/hns_roce_device.h
@@ -34,6 +34,7 @@
#define _HNS_ROCE_DEVICE_H

#include <rdma/ib_verbs.h>
+#include <rdma/ib_sa.h>
#include <linux/mutex.h>

#define DRV_NAME "hns_roce"
@@ -364,7 +365,7 @@ struct hns_roce_cmdq {
* Event mode: cmd register mutex protection,
* ensure to not exceed max_cmds and user use limit region
*/
- struct semaphore event_sem;
+ struct ib_semaphore event_sem;
int max_cmds;
spinlock_t context_lock;
int free_head;
diff --git a/include/rdma/ib_sa.h b/include/rdma/ib_sa.h
index 5ee7aab..1901042 100644
--- a/include/rdma/ib_sa.h
+++ b/include/rdma/ib_sa.h
@@ -291,6 +291,11 @@ struct ib_sa_service_rec {
#define IB_SA_GUIDINFO_REC_GID6 IB_SA_COMP_MASK(10)
#define IB_SA_GUIDINFO_REC_GID7 IB_SA_COMP_MASK(11)

+struct ib_semaphore {
+ wait_queue_head_t wq;
+ atomic_t count;
+};
+
struct ib_sa_guidinfo_rec {
__be16 lid;
u8 block_num;
--
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