drm/amdkfd: Drop interrupt SW ring buffer (6ee0ad2a) · Commits · 戴 / test

drivers/gpu/drm/amd/amdkfd/Makefile

+1 −2

Original line number	Diff line number	Diff line
		@@ -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

+1 −19

Original line number	Diff line number	Diff line
		@@ -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 @@ 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);
		@@ -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_interrupt.c

deleted100644 → 0

+0 −176

Original line number	Diff line number	Diff line
		/*
		* 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))
		;
		}

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

+0 −15

Original line number	Diff line number	Diff line
		@@ -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);

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