drm/amdkfd: Drop interrupt SW ring buffer

The work queue couldn't reliably prevent the SW ring buffer from
overflowing, so dmesg was spammed by

 kfd kfd: Interrupt ring overflow, dropping interrupt.

messages when running e.g. the Atlantis Substance demo from
https://wiki.unrealengine.com/Linux_Demos on Kaveri.

Since the SW ring buffer doesn't actually do anything at this point, just
remove it for now. When actual interrupt processing code is added to
amdkfd, it should try to do things immediately and only defer to work
queues when necessary.

Signed-off-by: Michel Dänzer <michel.daenzer@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Oded Gabbay <oded.gabbay@amd.com>

drivers/gpu/drm/amd/amdkfd/Makefile

@@ -8,7 +8,6 @@ amdkfd-y	:= kfd_module.o kfd_device.o kfd_chardev.o kfd_topology.o \
 		kfd_pasid.o kfd_doorbell.o kfd_flat_memory.o \
 		kfd_process.o kfd_queue.o kfd_mqd_manager.o \
 		kfd_kernel_queue.o kfd_packet_manager.o \
-		kfd_process_queue_manager.o kfd_device_queue_manager.o \
-		kfd_interrupt.o
+		kfd_process_queue_manager.o kfd_device_queue_manager.o
 
 obj-$(CONFIG_HSA_AMD)	+= amdkfd.o

drivers/gpu/drm/amd/amdkfd/kfd_device.c

@@ -192,13 +192,6 @@ 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",
@@ -237,8 +230,6 @@ bool kgd2kfd_device_init(struct kfd_dev *kfd,
 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);
@@ -254,7 +245,6 @@ 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);
 	}
 
@@ -296,13 +286,5 @@ int kgd2kfd_resume(struct kfd_dev *kfd)
 /* 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);
-	}
+	/* Process interrupts / schedule work as necessary */
 }

drivers/gpu/drm/amd/amdkfd/kfd_priv.h

@@ -135,22 +135,10 @@ struct kfd_dev {
 
 	struct kgd2kfd_shared_resources shared_resources;
 
-	void *interrupt_ring;
-	size_t interrupt_ring_size;
-	atomic_t interrupt_ring_rptr;
-	atomic_t interrupt_ring_wptr;
-	struct work_struct interrupt_work;
-	spinlock_t interrupt_lock;
-
 	/* QCM Device instance */
 	struct device_queue_manager *dqm;
 
 	bool init_complete;
-	/*
-	 * Interrupts of interest to KFD are copied
-	 * from the HW ring into a SW ring.
-	 */
-	bool interrupts_active;
 };
 
 /* KGD2KFD callbacks */
@@ -531,10 +519,7 @@ struct kfd_dev *kfd_device_by_pci_dev(const struct pci_dev *pdev);
 struct kfd_dev *kfd_topology_enum_kfd_devices(uint8_t idx);
 
 /* Interrupts */
-int kfd_interrupt_init(struct kfd_dev *dev);
-void kfd_interrupt_exit(struct kfd_dev *dev);
 void kgd2kfd_interrupt(struct kfd_dev *kfd, const void *ih_ring_entry);
-bool enqueue_ih_ring_entry(struct kfd_dev *kfd,	const void *ih_ring_entry);
 
 /* Power Management */
 void kgd2kfd_suspend(struct kfd_dev *kfd);