From: Aaron Taylor <ataylor@subgeniuskitty.com>
Date: Sun, 2 May 2021 08:02:49 +0000 (-0700)
Subject: Updated micscif/micscif_rma_dma.c to use new timer API introduced in Linux 4.14.0.
X-Git-Tag: first-build~5
X-Git-Url: https://git.subgeniuskitty.com/xeon-phi-kernel-module/.git/commitdiff_plain/446ac8fd5bb540e0073bc58deaed4507d3d5a2e6

Updated micscif/micscif_rma_dma.c to use new timer API introduced in Linux 4.14.0.

See also:

  - https://lwn.net/Articles/735887/

  - https://stackoverflow.com/questions/53839625
---

diff --git a/micscif/micscif_rma_dma.c b/micscif/micscif_rma_dma.c
index cf17321..9c4ea49 100644
--- a/micscif/micscif_rma_dma.c
+++ b/micscif/micscif_rma_dma.c
@@ -822,11 +822,23 @@ error:
 	return -ENOMEM;
 }
 
+// The timer API introduced in Linux 4.14.0 includes a from_timer() macro built
+// atop the container_of() macro. As the kernel moves away from using
+// timer_list.data, it quasi-assumes that the timer_list struct will be
+// contained in some larger struct that also contains the data, hence this
+// softlockup_wrapper struct since it allows us to avoid any serious code
+// changes to the driver.
+struct softlockup_wrapper {
+	struct timer_list timer;
+	unsigned long timer_fired;
+};
+
 #if !defined(WINDOWS) && !defined(CONFIG_PREEMPT)
 static int softlockup_threshold = 60;
-static void avert_softlockup(unsigned long data)
+static void avert_softlockup(struct timer_list *timer)
 {
-	*(unsigned long*)data = 1;
+	struct softlockup_wrapper *container= from_timer(container, timer, timer);
+	container->timer_fired = 1;
 }
 
 /*
@@ -838,11 +850,10 @@ static void avert_softlockup(unsigned long data)
  * timers are run at softirq context)
  *
  */
-static inline void add_softlockup_timer(struct timer_list *timer, unsigned long *data)
+static inline void add_softlockup_timer(struct timer_list *timer)
 {
-	setup_timer(timer, avert_softlockup, (unsigned long) data);
 	timer->expires = jiffies + usecs_to_jiffies(softlockup_threshold * 1000000 / 3);
-	add_timer(timer);
+	timer_setup(timer, avert_softlockup, 0);
 }
 
 static inline void del_softlockup_timer(struct timer_list *timer)
@@ -874,10 +885,10 @@ int micscif_rma_list_cpu_copy(struct mic_copy_work *work)
     uint64_t src_start_offset, dst_start_offset;
 	int ret = 0;
 #if !defined(WINDOWS) && !defined(CONFIG_PREEMPT)
-	unsigned long timer_fired = 0;
-	struct timer_list timer;
+	struct softlockup_wrapper tm_wrap;
 	int cpu = smp_processor_id();
-	add_softlockup_timer(&timer, &timer_fired);
+	tm_wrap.timer_fired = 0;
+	add_softlockup_timer(&tm_wrap.timer);
 #endif
 
 	remaining_len = work->len;
@@ -889,13 +900,13 @@ int micscif_rma_list_cpu_copy(struct mic_copy_work *work)
 		/* Ideally we should call schedule only if we didn't sleep
 		 * in between. But there is no way to know that.
 		 */
-		if (timer_fired) {
-			timer_fired = 0;
+		if (tm_wrap.timer_fired) {
+			tm_wrap.timer_fired = 0;
 			if (smp_processor_id() == cpu)
 				touch_softlockup_watchdog();
 			else
 				cpu = smp_processor_id();
-			add_softlockup_timer(&timer, &timer_fired);
+			add_softlockup_timer(&tm_wrap.timer);
 		}
 #endif
 		src_cache_off = src_offset & ~PAGE_MASK;
@@ -977,7 +988,7 @@ int micscif_rma_list_cpu_copy(struct mic_copy_work *work)
 	}
 error:
 #if !defined(WINDOWS) && !defined(CONFIG_PREEMPT)
-	del_softlockup_timer(&timer);
+	del_softlockup_timer(&tm_wrap.timer);
 #endif
 	return ret;
 }