gpu: nvgpu: Abstract condition variable

Add implementation for an abstracted condition variable. Implement it
using wait queue in Linux.

JIRA NVGPU-14

Change-Id: I211c590cca940ffc31d6c52141689f23f231e7da
Signed-off-by: Terje Bergstrom <tbergstrom@nvidia.com>
Reviewed-on: http://git-master/r/1469763
Reviewed-by: mobile promotions <svcmobile_promotions@nvidia.com>
Tested-by: mobile promotions <svcmobile_promotions@nvidia.com>

4 files changed, 203 insertions, 0 deletions

diff --git a/drivers/gpu/nvgpu/Makefile.nvgpu b/drivers/gpu/nvgpu/Makefile.nvgpu
index 82c9fec9..04107dbc 100644
--- a/drivers/gpu/nvgpu/Makefile.nvgpu
+++ b/drivers/gpu/nvgpu/Makefile.nvgpu
@@ -32,6 +32,7 @@ nvgpu-y := \
         common/linux/ioctl_channel.o \
         common/linux/ioctl_tsg.o \
         common/linux/log.o \
+        common/linux/cond.o \
         common/linux/nvgpu_mem.o \
         common/linux/dma.o \
         common/linux/soc.o \
diff --git a/drivers/gpu/nvgpu/common/linux/cond.c b/drivers/gpu/nvgpu/common/linux/cond.c
new file mode 100644
index 00000000..633c34fd
--- /dev/null
+++ b/drivers/gpu/nvgpu/common/linux/cond.c
@@ -0,0 +1,73 @@
+/*
+ * Copyright (c) 2017, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <linux/wait.h>
+#include <linux/sched.h>
+
+#include <nvgpu/cond.h>
+
+int nvgpu_cond_init(struct nvgpu_cond *cond)
+{
+        init_waitqueue_head(&cond->wq);
+        cond->initialized = true;
+
+        return 0;
+}
+
+void nvgpu_cond_destroy(struct nvgpu_cond *cond)
+{
+        cond->initialized = false;
+}
+
+int nvgpu_cond_signal(struct nvgpu_cond *cond)
+{
+        if (!cond->initialized)
+                return -EINVAL;
+
+        wake_up(&cond->wq);
+
+        return 0;
+}
+
+int nvgpu_cond_signal_interruptible(struct nvgpu_cond *cond)
+{
+        if (!cond->initialized)
+                return -EINVAL;
+
+        wake_up_interruptible(&cond->wq);
+
+        return 0;
+}
+
+int nvgpu_cond_broadcast(struct nvgpu_cond *cond)
+{
+        if (!cond->initialized)
+                return -EINVAL;
+
+        wake_up_all(&cond->wq);
+
+        return 0;
+}
+
+int nvgpu_cond_broadcast_interruptible(struct nvgpu_cond *cond)
+{
+        if (!cond->initialized)
+                return -EINVAL;
+
+        wake_up_interruptible_all(&cond->wq);
+
+        return 0;
+}
diff --git a/drivers/gpu/nvgpu/include/nvgpu/cond.h b/drivers/gpu/nvgpu/include/nvgpu/cond.h
new file mode 100644
index 00000000..9cd2c93f
--- /dev/null
+++ b/drivers/gpu/nvgpu/include/nvgpu/cond.h
@@ -0,0 +1,96 @@
+/*
+ * Copyright (c) 2017, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __NVGPU_COND_H__
+#define __NVGPU_COND_H__
+
+#ifdef __KERNEL__
+#include <nvgpu/linux/cond.h>
+#endif
+
+/*
+ * struct nvgpu_cond
+ *
+ * Should be implemented per-OS in a separate library
+ */
+struct nvgpu_cond;
+
+/**
+ * nvgpu_cond_init - Initialize a condition variable
+ *
+ * @cond - The condition variable to initialize
+ *
+ * Initialize a condition variable before using it.
+ */
+int nvgpu_cond_init(struct nvgpu_cond *cond);
+
+/**
+ * nvgpu_cond_signal - Signal a condition variable
+ *
+ * @cond - The condition variable to signal
+ *
+ * Wake up a waiter for a condition variable to check if its condition has been
+ * satisfied.
+ *
+ * The waiter is using an uninterruptible wait.
+ */
+int nvgpu_cond_signal(struct nvgpu_cond *cond);
+
+/**
+ * nvgpu_cond_signal_interruptible - Signal a condition variable
+ *
+ * @cond - The condition variable to signal
+ *
+ * Wake up a waiter for a condition variable to check if its condition has been
+ * satisfied.
+ *
+ * The waiter is using an interruptible wait.
+ */
+int nvgpu_cond_signal_interruptible(struct nvgpu_cond *cond);
+
+/**
+ * nvgpu_cond_broadcast - Signal all waiters of a condition variable
+ *
+ * @cond - The condition variable to signal
+ *
+ * Wake up all waiters for a condition variable to check if their conditions
+ * have been satisfied.
+ *
+ * The waiters are using an uninterruptible wait.
+ */
+int nvgpu_cond_broadcast(struct nvgpu_cond *cond);
+
+/**
+ * nvgpu_cond_broadcast_interruptible - Signal all waiters of a condition
+ * variable
+ *
+ * @cond - The condition variable to signal
+ *
+ * Wake up all waiters for a condition variable to check if their conditions
+ * have been satisfied.
+ *
+ * The waiters are using an interruptible wait.
+ */
+int nvgpu_cond_broadcast_interruptible(struct nvgpu_cond *cond);
+
+/**
+ * nvgpu_cond_destroy - Destroy a condition variable
+ *
+ * @cond - The condition variable to destroy
+ */
+void nvgpu_cond_destroy(struct nvgpu_cond *cond);
+
+#endif /* __NVGPU_COND_H__ */
diff --git a/drivers/gpu/nvgpu/include/nvgpu/linux/cond.h b/drivers/gpu/nvgpu/include/nvgpu/linux/cond.h
new file mode 100644
index 00000000..3eb52861
--- /dev/null
+++ b/drivers/gpu/nvgpu/include/nvgpu/linux/cond.h
@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2017, NVIDIA CORPORATION.  All rights reserved.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#ifndef __NVGPU_COND_LINUX_H__
+#define __NVGPU_COND_LINUX_H__
+
+#include <linux/wait.h>
+
+struct nvgpu_cond {
+        bool initialized;
+        wait_queue_head_t wq;
+};
+
+#define NVGPU_COND_WAIT(c, condition, timeout_ms) \
+        wait_event_timeout((c)->wq, condition, timeout_ms)
+
+#define NVGPU_COND_WAIT_INTERRUPTIBLE(c, condition, timeout_ms) \
+        wait_event_interruptible_timeout((c)->wq, condition, timeout_ms)
+
+#endif /* __NVGPU_LOCK_LINUX_H__ */