amdkfd: Add interrupt handling module

This patch adds the interrupt handling module, in kfd_interrupt.c, and its
related members in different data structures to the amdkfd driver.

The amdkfd interrupt module maintains an internal interrupt ring per amdkfd
device. The internal interrupt ring contains interrupts that needs further
handling. The extra handling is deferred to a later time through a workqueue.

There's no acknowledgment for the interrupts we use. The hardware simply queues
a new interrupt each time without waiting.

The fixed-size internal queue means that it's possible for us to lose
interrupts because we have no back-pressure to the hardware.

v3:

Move amdkfd from drm/radeon/ to drm/amd/
Change device init
Made sure spin lock is taken only if init is complete
Moved bool field to the end of the structure

Signed-off-by: Andrew Lewycky <Andrew.Lewycky@amd.com>
Signed-off-by: Oded Gabbay <oded.gabbay@amd.com>

1 files changed, 22 insertions, 1 deletions

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device.c b/drivers/gpu/drm/amd/amdkfd/kfd_device.c
index bdf3e94..9beb6f7 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_device.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_device.c
@@ -31,6 +31,7 @@
 
 static const struct kfd_device_info kaveri_device_info = {
 	.max_pasid_bits = 16,
+	.ih_ring_entry_size = 4 * sizeof(uint32_t),
 	.mqd_size_aligned = MQD_SIZE_ALIGNED
 };
 
@@ -191,6 +192,13 @@ bool kgd2kfd_device_init(struct kfd_dev *kfd,
 		goto kfd_topology_add_device_error;
 	}
 
+	if (kfd_interrupt_init(kfd)) {
+		dev_err(kfd_device,
+			"Error initializing interrupts for device (%x:%x)\n",
+			kfd->pdev->vendor, kfd->pdev->device);
+		goto kfd_interrupt_error;
+	}
+
 	if (!device_iommu_pasid_init(kfd)) {
 		dev_err(kfd_device,
 			"Error initializing iommuv2 for device (%x:%x)\n",
@@ -229,6 +237,8 @@ dqm_start_error:
 device_queue_manager_error:
 	amd_iommu_free_device(kfd->pdev);
 device_iommu_pasid_error:
+	kfd_interrupt_exit(kfd);
+kfd_interrupt_error:
 	kfd_topology_remove_device(kfd);
 kfd_topology_add_device_error:
 	kfd2kgd->fini_sa_manager(kfd->kgd);
@@ -244,6 +254,7 @@ void kgd2kfd_device_exit(struct kfd_dev *kfd)
 	if (kfd->init_complete) {
 		device_queue_manager_uninit(kfd->dqm);
 		amd_iommu_free_device(kfd->pdev);
+		kfd_interrupt_exit(kfd);
 		kfd_topology_remove_device(kfd);
 	}
 
@@ -281,6 +292,16 @@ int kgd2kfd_resume(struct kfd_dev *kfd)
 	return 0;
 }
 
-void kgd2kfd_interrupt(struct kfd_dev *dev, const void *ih_ring_entry)
+/* This is called directly from KGD at ISR. */
+void kgd2kfd_interrupt(struct kfd_dev *kfd, const void *ih_ring_entry)
 {
+	if (kfd->init_complete) {
+		spin_lock(&kfd->interrupt_lock);
+
+		if (kfd->interrupts_active
+		    && enqueue_ih_ring_entry(kfd, ih_ring_entry))
+			schedule_work(&kfd->interrupt_work);
+
+		spin_unlock(&kfd->interrupt_lock);
+	}
 }