[PATCH v2 25/25] amdkfd: Implement the PMC Acquire/Release IOCTLs

[Oded Gabbay <oded.gabbay@amd.com>]

From: Evgeny Pinchuk <evgeny.pinchuk@amd.com>

Signed-off-by: Ben Goz <ben.goz@amd.com>
Signed-off-by: Oded Gabbay <oded.gabbay@amd.com>
---
 drivers/gpu/drm/radeon/amdkfd/kfd_chardev.c | 46 +++++++++++++++++++++++++++--
 drivers/gpu/drm/radeon/amdkfd/kfd_device.c  |  2 ++
 drivers/gpu/drm/radeon/amdkfd/kfd_priv.h    |  5 ++++
 drivers/gpu/drm/radeon/amdkfd/kfd_process.c |  6 ++++
 4 files changed, 57 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/drm/radeon/amdkfd/kfd_chardev.c b/drivers/gpu/drm/radeon/amdkfd/kfd_chardev.c
index 1e19504..be90ab9 100644
--- a/drivers/gpu/drm/radeon/amdkfd/kfd_chardev.c
+++ b/drivers/gpu/drm/radeon/amdkfd/kfd_chardev.c
@@ -391,12 +391,54 @@ static int kfd_ioctl_get_process_apertures(struct file *filp, struct kfd_process
 
 static long kfd_ioctl_pmc_acquire_access(struct file *filp, struct kfd_process *p, void __user *arg)
 {
-	return -ENODEV;
+	struct kfd_ioctl_pmc_acquire_access_args args;
+	struct kfd_dev *dev;
+	int err = -EBUSY;
+
+	if (copy_from_user(&args, arg, sizeof(args)))
+		return -EFAULT;
+
+	dev = kfd_device_by_id(args.gpu_id);
+	if (dev == NULL)
+		return -EINVAL;
+
+	spin_lock(&dev->pmc_access_lock);
+	if (dev->pmc_locking_process == NULL) {
+		dev->pmc_locking_process = p;
+		dev->pmc_locking_trace = args.trace_id;
+		err = 0;
+	} else if (dev->pmc_locking_process == p && dev->pmc_locking_trace == args.trace_id) {
+		/* Same trace already has an access. Returning success */
+		err = 0;
+	}
+
+	spin_unlock(&dev->pmc_access_lock);
+
+	return err;
 }
 
 static long kfd_ioctl_pmc_release_access(struct file *filp, struct kfd_process *p, void __user *arg)
 {
-	return -ENODEV;
+	struct kfd_ioctl_pmc_release_access_args args;
+	struct kfd_dev *dev;
+	int err = -EINVAL;
+
+	if (copy_from_user(&args, arg, sizeof(args)))
+		return -EFAULT;
+
+	dev = kfd_device_by_id(args.gpu_id);
+	if (dev == NULL)
+		return -EINVAL;
+
+	spin_lock(&dev->pmc_access_lock);
+	if (dev->pmc_locking_process == p && dev->pmc_locking_trace == args.trace_id) {
+		dev->pmc_locking_process = NULL;
+		dev->pmc_locking_trace = 0;
+		err = 0;
+	}
+	spin_unlock(&dev->pmc_access_lock);
+
+	return err;
 }
 
 static long kfd_ioctl(struct file *filep, unsigned int cmd, unsigned long arg)
diff --git a/drivers/gpu/drm/radeon/amdkfd/kfd_device.c b/drivers/gpu/drm/radeon/amdkfd/kfd_device.c
index 6a7a8b2..f1cbc46 100644
--- a/drivers/gpu/drm/radeon/amdkfd/kfd_device.c
+++ b/drivers/gpu/drm/radeon/amdkfd/kfd_device.c
@@ -184,6 +184,8 @@ bool kgd2kfd_device_init(struct kfd_dev *kfd,
 		return false;
 	}
 
+	spin_lock_init(&kfd->pmc_access_lock);
+
 	kfd->init_complete = true;
 	dev_info(kfd_device, "added device (%x:%x)\n", kfd->pdev->vendor,
 		 kfd->pdev->device);
diff --git a/drivers/gpu/drm/radeon/amdkfd/kfd_priv.h b/drivers/gpu/drm/radeon/amdkfd/kfd_priv.h
index 1db1ede..a5356d1 100644
--- a/drivers/gpu/drm/radeon/amdkfd/kfd_priv.h
+++ b/drivers/gpu/drm/radeon/amdkfd/kfd_priv.h
@@ -131,6 +131,11 @@ struct kfd_dev {
 
 	/* QCM Device instance */
 	struct device_queue_manager *dqm;
+
+	/* Performance counters exclusivity lock */
+	spinlock_t pmc_access_lock;
+	struct kfd_process *pmc_locking_process;
+	uint64_t pmc_locking_trace;
 };
 
 /* KGD2KFD callbacks */
diff --git a/drivers/gpu/drm/radeon/amdkfd/kfd_process.c b/drivers/gpu/drm/radeon/amdkfd/kfd_process.c
index bcc004f..a67c239 100644
--- a/drivers/gpu/drm/radeon/amdkfd/kfd_process.c
+++ b/drivers/gpu/drm/radeon/amdkfd/kfd_process.c
@@ -98,6 +98,12 @@ static void free_process(struct kfd_process *p)
 	BUG_ON(p == NULL);
 
 	list_for_each_entry_safe(pdd, temp, &p->per_device_data, per_device_list) {
+		spin_lock(&pdd->dev->pmc_access_lock);
+		if (pdd->dev->pmc_locking_process == p) {
+			pdd->dev->pmc_locking_process = NULL;
+			pdd->dev->pmc_locking_trace = 0;
+		}
+		spin_unlock(&pdd->dev->pmc_access_lock);
 		amd_iommu_unbind_pasid(pdd->dev->pdev, p->pasid);
 		list_del(&pdd->per_device_list);
 		kfree(pdd);
-- 
1.9.1