amdgpu_vm.c

/*
 * Copyright 2008 Advanced Micro Devices, Inc.
 * Copyright 2008 Red Hat Inc.
 * Copyright 2009 Jerome Glisse.
 *
 * 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.
 *
 * Authors: Dave Airlie
 *          Alex Deucher
 *          Jerome Glisse
 */
#include <linux/dma-fence-array.h>
#include <linux/interval_tree_generic.h>
#include <linux/idr.h>
#include <drm/drmP.h>
#include <drm/amdgpu_drm.h>
#include "amdgpu.h"
#include "amdgpu_trace.h"

/*
 * PASID manager
 *
 * PASIDs are global address space identifiers that can be shared
 * between the GPU, an IOMMU and the driver. VMs on different devices
 * may use the same PASID if they share the same address
 * space. Therefore PASIDs are allocated using a global IDA. VMs are
 * looked up from the PASID per amdgpu_device.
 */
static DEFINE_IDA(amdgpu_vm_pasid_ida);

/**
 * amdgpu_vm_alloc_pasid - Allocate a PASID
 * @bits: Maximum width of the PASID in bits, must be at least 1
 *
 * Allocates a PASID of the given width while keeping smaller PASIDs
 * available if possible.
 *
 * Returns a positive integer on success. Returns %-EINVAL if bits==0.
 * Returns %-ENOSPC if no PASID was available. Returns %-ENOMEM on
 * memory allocation failure.
 */
int amdgpu_vm_alloc_pasid(unsigned int bits)
{
	int pasid = -EINVAL;

	for (bits = min(bits, 31U); bits > 0; bits--) {
		pasid = ida_simple_get(&amdgpu_vm_pasid_ida,
				       1U << (bits - 1), 1U << bits,
				       GFP_KERNEL);
		if (pasid != -ENOSPC)
			break;
	}

	return pasid;