diff options
Diffstat (limited to 'drivers/gpu/drm/amd/amdkfd/kfd_interrupt.c')
-rw-r--r-- | drivers/gpu/drm/amd/amdkfd/kfd_interrupt.c | 176 |
1 files changed, 0 insertions, 176 deletions
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_interrupt.c b/drivers/gpu/drm/amd/amdkfd/kfd_interrupt.c deleted file mode 100644 index 5b999095a1f7..000000000000 --- a/drivers/gpu/drm/amd/amdkfd/kfd_interrupt.c +++ /dev/null @@ -1,176 +0,0 @@ -/* - * Copyright 2014 Advanced Micro Devices, Inc. - * - * Permission is hereby granted, free of charge, to any person obtaining a - * copy of this software and associated documentation files (the "Software"), - * to deal in the Software without restriction, including without limitation - * the rights to use, copy, modify, merge, publish, distribute, sublicense, - * and/or sell copies of the Software, and to permit persons to whom the - * Software is furnished to do so, subject to the following conditions: - * - * The above copyright notice and this permission notice shall be included in - * all copies or substantial portions of the Software. - * - * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR - * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, - * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL - * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR - * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, - * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR - * OTHER DEALINGS IN THE SOFTWARE. - */ - -/* - * KFD Interrupts. - * - * AMD GPUs deliver interrupts by pushing an interrupt description onto the - * interrupt ring and then sending an interrupt. KGD receives the interrupt - * in ISR and sends us a pointer to each new entry on the interrupt ring. - * - * We generally can't process interrupt-signaled events from ISR, so we call - * out to each interrupt client module (currently only the scheduler) to ask if - * each interrupt is interesting. If they return true, then it requires further - * processing so we copy it to an internal interrupt ring and call each - * interrupt client again from a work-queue. - * - * 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. - */ - -#include <linux/slab.h> -#include <linux/device.h> -#include "kfd_priv.h" - -#define KFD_INTERRUPT_RING_SIZE 256 - -static void interrupt_wq(struct work_struct *); - -int kfd_interrupt_init(struct kfd_dev *kfd) -{ - void *interrupt_ring = kmalloc_array(KFD_INTERRUPT_RING_SIZE, - kfd->device_info->ih_ring_entry_size, - GFP_KERNEL); - if (!interrupt_ring) - return -ENOMEM; - - kfd->interrupt_ring = interrupt_ring; - kfd->interrupt_ring_size = - KFD_INTERRUPT_RING_SIZE * kfd->device_info->ih_ring_entry_size; - atomic_set(&kfd->interrupt_ring_wptr, 0); - atomic_set(&kfd->interrupt_ring_rptr, 0); - - spin_lock_init(&kfd->interrupt_lock); - - INIT_WORK(&kfd->interrupt_work, interrupt_wq); - - kfd->interrupts_active = true; - - /* - * After this function returns, the interrupt will be enabled. This - * barrier ensures that the interrupt running on a different processor - * sees all the above writes. - */ - smp_wmb(); - - return 0; -} - -void kfd_interrupt_exit(struct kfd_dev *kfd) -{ - /* - * Stop the interrupt handler from writing to the ring and scheduling - * workqueue items. The spinlock ensures that any interrupt running - * after we have unlocked sees interrupts_active = false. - */ - unsigned long flags; - - spin_lock_irqsave(&kfd->interrupt_lock, flags); - kfd->interrupts_active = false; - spin_unlock_irqrestore(&kfd->interrupt_lock, flags); - - /* - * Flush_scheduled_work ensures that there are no outstanding - * work-queue items that will access interrupt_ring. New work items - * can't be created because we stopped interrupt handling above. - */ - flush_scheduled_work(); - - kfree(kfd->interrupt_ring); -} - -/* - * This assumes that it can't be called concurrently with itself - * but only with dequeue_ih_ring_entry. - */ -bool enqueue_ih_ring_entry(struct kfd_dev *kfd, const void *ih_ring_entry) -{ - unsigned int rptr = atomic_read(&kfd->interrupt_ring_rptr); - unsigned int wptr = atomic_read(&kfd->interrupt_ring_wptr); - - if ((rptr - wptr) % kfd->interrupt_ring_size == - kfd->device_info->ih_ring_entry_size) { - /* This is very bad, the system is likely to hang. */ - dev_err_ratelimited(kfd_chardev(), - "Interrupt ring overflow, dropping interrupt.\n"); - return false; - } - - memcpy(kfd->interrupt_ring + wptr, ih_ring_entry, - kfd->device_info->ih_ring_entry_size); - - wptr = (wptr + kfd->device_info->ih_ring_entry_size) % - kfd->interrupt_ring_size; - smp_wmb(); /* Ensure memcpy'd data is visible before wptr update. */ - atomic_set(&kfd->interrupt_ring_wptr, wptr); - - return true; -} - -/* - * This assumes that it can't be called concurrently with itself - * but only with enqueue_ih_ring_entry. - */ -static bool dequeue_ih_ring_entry(struct kfd_dev *kfd, void *ih_ring_entry) -{ - /* - * Assume that wait queues have an implicit barrier, i.e. anything that - * happened in the ISR before it queued work is visible. - */ - - unsigned int wptr = atomic_read(&kfd->interrupt_ring_wptr); - unsigned int rptr = atomic_read(&kfd->interrupt_ring_rptr); - - if (rptr == wptr) - return false; - - memcpy(ih_ring_entry, kfd->interrupt_ring + rptr, - kfd->device_info->ih_ring_entry_size); - - rptr = (rptr + kfd->device_info->ih_ring_entry_size) % - kfd->interrupt_ring_size; - - /* - * Ensure the rptr write update is not visible until - * memcpy has finished reading. - */ - smp_mb(); - atomic_set(&kfd->interrupt_ring_rptr, rptr); - - return true; -} - -static void interrupt_wq(struct work_struct *work) -{ - struct kfd_dev *dev = container_of(work, struct kfd_dev, - interrupt_work); - - uint32_t ih_ring_entry[DIV_ROUND_UP( - dev->device_info->ih_ring_entry_size, - sizeof(uint32_t))]; - - while (dequeue_ih_ring_entry(dev, ih_ring_entry)) - ; -} |