diff options
| -rw-r--r-- | drivers/gpu/drm/amd/amdkfd/Makefile | 3 | ||||
| -rw-r--r-- | drivers/gpu/drm/amd/amdkfd/kfd_device.c | 23 | ||||
| -rw-r--r-- | drivers/gpu/drm/amd/amdkfd/kfd_interrupt.c | 176 | ||||
| -rw-r--r-- | drivers/gpu/drm/amd/amdkfd/kfd_priv.h | 21 |
4 files changed, 218 insertions, 5 deletions
diff --git a/drivers/gpu/drm/amd/amdkfd/Makefile b/drivers/gpu/drm/amd/amdkfd/Makefile index 307a309110e6..be6246de5091 100644 --- a/drivers/gpu/drm/amd/amdkfd/Makefile +++ b/drivers/gpu/drm/amd/amdkfd/Makefile @@ -8,6 +8,7 @@ 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_process_queue_manager.o kfd_device_queue_manager.o \ + kfd_interrupt.o obj-$(CONFIG_HSA_AMD) += amdkfd.o diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_device.c b/drivers/gpu/drm/amd/amdkfd/kfd_device.c index bdf3e94590bd..9beb6f7bba9d 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); + } } diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_interrupt.c b/drivers/gpu/drm/amd/amdkfd/kfd_interrupt.c new file mode 100644 index 000000000000..5b999095a1f7 --- /dev/null +++ b/drivers/gpu/drm/amd/amdkfd/kfd_interrupt.c @@ -0,0 +1,176 @@ +/* + * 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)) + ; +} diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h index 7f3b4fdaa26e..2bc34aa1ad95 100644 --- a/drivers/gpu/drm/amd/amdkfd/kfd_priv.h +++ b/drivers/gpu/drm/amd/amdkfd/kfd_priv.h @@ -135,10 +135,22 @@ 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 */ @@ -493,11 +505,14 @@ 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 */ -void kgd2kfd_interrupt(struct kfd_dev *dev, const void *ih_ring_entry); +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 *dev); -int kgd2kfd_resume(struct kfd_dev *dev); +void kgd2kfd_suspend(struct kfd_dev *kfd); +int kgd2kfd_resume(struct kfd_dev *kfd); /* amdkfd Apertures */ int kfd_init_apertures(struct kfd_process *process); |