path: root/drivers/gpu/drm/amd/amdkfd/kfd_events.c

// SPDX-License-Identifier: GPL-2.0 OR MIT
/*
 * Copyright 2014-2022 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.
 */

#include <linux/mm_types.h>
#include <linux/slab.h>
#include <linux/types.h>
#include <linux/sched/signal.h>
#include <linux/sched/mm.h>
#include <linux/uaccess.h>
#include <linux/mman.h>
#include <linux/memory.h>
#include "kfd_priv.h"
#include "kfd_events.h"
#include "kfd_device_queue_manager.h"
#include <linux/device.h>

/*
 * Wrapper around wait_queue_entry_t
 */
struct kfd_event_waiter {
	wait_queue_entry_t wait;
	struct kfd_event *event; /* Event to wait for */
	bool activated;		 /* Becomes true when event is signaled */
	bool event_age_enabled;  /* set to true when last_event_age is non-zero */
};

/*
 * Each signal event needs a 64-bit signal slot where the signaler will write
 * a 1 before sending an interrupt. (This is needed because some interrupts
 * do not contain enough spare data bits to identify an event.)
 * We get whole pages and map them to the process VA.
 * Individual signal events use their event_id as slot index.
 */
struct kfd_signal_page {
	uint64_t *kernel_address;
	uint64_t __user *user_address;
	bool need_to_free_pages;
};

static uint64_t *page_slots(struct kfd_signal_page *page)
{
	return page->kernel_address;
}

static struct kfd_signal_page *allocate_signal_page(struct kfd_process *p)
{
	void *backing_store;
	struct kfd_signal_page *page;

	page = kzalloc(sizeof(*page), GFP_KERNEL);
	if (!page)
		return NULL;

	backing_store = (void *) __get_free_pages(GFP_KERNEL,
					get_order(KFD_SIGNAL_EVENT_LIMIT * 8));
	if (!backing_store)
		goto fail_alloc_signal_store;

	/* Initialize all events to unsignaled */
	memset(backing_store, (uint8_t) UNSIGNALED_EVENT_SLOT,
	       KFD_SIGNAL_EVENT_LIMIT * 8);

	page->kernel_address = backing_store;
	page->need_to_free_pages = true;
	pr_debug("Allocated new event signal page at %p, for process %p\n",
			page, p);

	return page;

fail_alloc_signal_store:
	kfree(page);
	return NULL;
}

static int allocate_event_notification_slot(<