net/ena: handle spurious wakeups in wait event

pthread_cond_timedwait() may spuriously wakeup according to POSIX.
Therefore it is required to check whether predicate is actually true
before finishing the waiting loop.

Signed-off-by: Stanislaw Kardach <kda@semihalf.com>
Reviewed-by: Michal Krawczyk <mk@semihalf.com>
Reviewed-by: Igor Chauskin <igorch@amazon.com>
Reviewed-by: Shay Agroskin <shayagr@amazon.com>

diff --git a/drivers/net/ena/base/ena_plat_dpdk.h b/drivers/net/ena/base/ena_plat_dpdk.h
index 13264d0..f66df95 100644 (file)
--- a/drivers/net/ena/base/ena_plat_dpdk.h
+++ b/drivers/net/ena/base/ena_plat_dpdk.h
@@ -77,6 +77,14 @@ typedef uint64_t dma_addr_t;
 #define mmiowb rte_io_wmb
 #define __iomem
 
+#ifndef READ_ONCE
+#define READ_ONCE(var) (*((volatile typeof(var) *)(&(var))))
+#endif
+
+#define READ_ONCE8(var) READ_ONCE(var)
+#define READ_ONCE16(var) READ_ONCE(var)
+#define READ_ONCE32(var) READ_ONCE(var)
+
 #define US_PER_S 1000000
 #define ENA_GET_SYSTEM_USECS()                                                \
        (rte_get_timer_cycles() * US_PER_S / rte_get_timer_hz())
@@ -138,40 +146,59 @@ extern int ena_logtype_com;
        ({(void)flags; rte_spinlock_unlock(&(spinlock)); })
 #define ENA_SPINLOCK_DESTROY(spinlock) ((void)(spinlock))
 
-#define q_waitqueue_t                                                         \
-       struct {                                                               \
-               pthread_cond_t cond;                                           \
-               pthread_mutex_t mutex;                                         \
-       }
+typedef struct {
+       pthread_cond_t cond;
+       pthread_mutex_t mutex;
+       uint8_t flag;
+} ena_wait_event_t;
 
-#define ena_wait_queue_t q_waitqueue_t
-
-#define ENA_WAIT_EVENT_INIT(waitqueue)                                        \
+#define ENA_WAIT_EVENT_INIT(waitevent)                                        \
        do {                                                                   \
-               pthread_mutex_init(&(waitqueue).mutex, NULL);                  \
-               pthread_cond_init(&(waitqueue).cond, NULL);                    \
+               ena_wait_event_t *_we = &(waitevent);                          \
+               pthread_mutex_init(&_we->mutex, NULL);                         \
+               pthread_cond_init(&_we->cond, NULL);                           \
+               _we->flag = 0;                                                 \
        } while (0)
 
 #define ENA_WAIT_EVENT_WAIT(waitevent, timeout)                                       \
        do {                                                                   \
+               ena_wait_event_t *_we = &(waitevent);                          \
+               typeof(timeout) _tmo = (timeout);                              \
+               int ret = 0;                                                   \
                struct timespec wait;                                          \
                struct timeval now;                                            \
                unsigned long timeout_us;                                      \
                gettimeofday(&now, NULL);                                      \
-               wait.tv_sec = now.tv_sec + (timeout) / 1000000UL;              \
-               timeout_us = (timeout) % 1000000UL;                            \
+               wait.tv_sec = now.tv_sec + _tmo / 1000000UL;                   \
+               timeout_us = _tmo % 1000000UL;                                 \
                wait.tv_nsec = (now.tv_usec + timeout_us) * 1000UL;            \
-               pthread_mutex_lock(&(waitevent).mutex);                        \
-               pthread_cond_timedwait(&(waitevent).cond,                      \
-                               &(waitevent).mutex, &wait);                    \
-               pthread_mutex_unlock(&(waitevent).mutex);                      \
+               pthread_mutex_lock(&_we->mutex);                               \
+               while (ret == 0 && !_we->flag) {                               \
+                       ret = pthread_cond_timedwait(&_we->cond,               \
+                               &_we->mutex, &wait);                           \
+               }                                                              \
+               /* Asserts only if not working on ena_wait_event_t */          \
+               if (unlikely(ret != 0 && ret != ETIMEDOUT))                    \
+                       ena_trc_err(NULL,                                      \
+                               "Invalid wait event. pthread ret: %d\n", ret); \
+               else if (unlikely(ret == ETIMEDOUT))                           \
+                       ena_trc_err(NULL,                                      \
+                               "Timeout waiting for " #waitevent "\n");       \
+               _we->flag = 0;                                                 \
+               pthread_mutex_unlock(&_we->mutex);                             \
+       } while (0)
+#define ENA_WAIT_EVENT_SIGNAL(waitevent)                                      \
+       do {                                                                   \
+               ena_wait_event_t *_we = &(waitevent);                          \
+               pthread_mutex_lock(&_we->mutex);                               \
+               _we->flag = 1;                                                 \
+               pthread_cond_signal(&_we->cond);                               \
+               pthread_mutex_unlock(&_we->mutex);                             \
        } while (0)
-#define ENA_WAIT_EVENT_SIGNAL(waitevent) pthread_cond_signal(&waitevent.cond)
 /* pthread condition doesn't need to be rearmed after usage */
 #define ENA_WAIT_EVENT_CLEAR(...)
-#define ENA_WAIT_EVENT_DESTROY(waitqueue) ((void)(waitqueue))
+#define ENA_WAIT_EVENT_DESTROY(waitevent) ((void)(waitevent))
 
-#define ena_wait_event_t ena_wait_queue_t
 #define ENA_MIGHT_SLEEP()
 
 #define ena_time_t uint64_t
@@ -289,14 +316,6 @@ extern rte_atomic64_t ena_alloc_cnt;
        ((timeout_us) * rte_get_timer_hz() / 1000000 + rte_get_timer_cycles())
 #define ENA_WAIT_EVENTS_DESTROY(admin_queue) ((void)(admin_queue))
 
-#ifndef READ_ONCE
-#define READ_ONCE(var) (*((volatile typeof(var) *)(&(var))))
-#endif
-
-#define READ_ONCE8(var) READ_ONCE(var)
-#define READ_ONCE16(var) READ_ONCE(var)
-#define READ_ONCE32(var) READ_ONCE(var)
-
 /* The size must be 8 byte align */
 #define ENA_MEMCPY_TO_DEVICE_64(dst, src, size)                                       \
        do {                                                                   \