ntb_hw_amd.c

/*
 * This file is provided under a dual BSD/GPLv2 license.  When using or
 *   redistributing this file, you may do so under either license.
 *
 *   GPL LICENSE SUMMARY
 *
 *   Copyright (C) 2016 Advanced Micro Devices, Inc. All Rights Reserved.
 *   Copyright (C) 2016 T-Platforms. All Rights Reserved.
 *
 *   This program is free software; you can redistribute it and/or modify
 *   it under the terms of version 2 of the GNU General Public License as
 *   published by the Free Software Foundation.
 *
 *   BSD LICENSE
 *
 *   Copyright (C) 2016 Advanced Micro Devices, Inc. All Rights Reserved.
 *   Copyright (C) 2016 T-Platforms. All Rights Reserved.
 *
 *   Redistribution and use in source and binary forms, with or without
 *   modification, are permitted provided that the following conditions
 *   are met:
 *
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copy
 *       notice, this list of conditions and the following disclaimer in
 *       the documentation and/or other materials provided with the
 *       distribution.
 *     * Neither the name of AMD Corporation nor the names of its
 *       contributors may be used to endorse or promote products derived
 *       from this software without specific prior written permission.
 *
 *   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 *   "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 *   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
 *   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
 *   OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 *   SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 *   LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 *   OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * AMD PCIe NTB Linux driver
 *
 * Contact Information:
 * Xiangliang Yu <Xiangliang.Yu@amd.com>
 */

#include <linux/debugfs.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/module.h>
#include <linux/acpi.h>
#include <linux/pci.h>
#include <linux/random.h>
#include <linux/slab.h>
#include <linux/ntb.h>

#include "ntb_hw_amd.h"

#define NTB_NAME	"ntb_hw_amd"
#define NTB_DESC	"AMD(R) PCI-E Non-Transparent Bridge Driver"
#define NTB_VER		"1.0"

MODULE_DESCRIPTION(NTB_DESC);
MODULE_VERSION(NTB_VER);
MODULE_LICENSE("Dual BSD/GPL");
MODULE_AUTHOR("AMD Inc.");

static const struct file_operations amd_ntb_debugfs_info;
static struct dentry *debugfs_dir;

static int ndev_mw_to_bar(struct amd_ntb_dev *ndev, int idx)
{
	if (idx < 0 || idx > ndev->mw_count)
		return -EINVAL;

	return ndev->dev_data->mw_idx << idx;
}

static int amd_ntb_mw_count(struct ntb_dev *ntb, int pidx)
{
	if (pidx != NTB_DEF_PEER_IDX)
		return -EINVAL;

	return ntb_ndev(ntb)->mw_count;
}

static int amd_ntb_mw_get_align(struct ntb_dev *ntb, int pidx, int idx,
				resource_size_t *addr_align,
				resource_size_t *size_align,
				resource_size_t *size_max)
{
	struct amd_ntb_dev *ndev = ntb_ndev(ntb);
	int bar;

	if (pidx != NTB_DEF_PEER_IDX)
		return -EINVAL;

	bar = ndev_mw_to_bar(ndev, idx);
	if (bar < 0)
		return bar;

	if (addr_align)
		*addr_align = SZ_4K;

	if (size_align)
		*size_align = 1;

	if (size_max)
		*size_max = pci_resource_len(ndev->ntb.pdev, bar);

	return 0;
}

static int amd_ntb_mw_set_trans(struct ntb_dev *ntb, int pidx, int idx,
				dma_addr_t addr, resource_size_t size)
{
	struct amd_ntb_dev *ndev = ntb_ndev(ntb);
	unsigned long xlat_reg, limit_reg = 0;
	resource_size_t mw_size;
	void __iomem *mmio, *peer_mmio;
	u64 base_addr, limit, reg_val;
	int bar;

	if (pidx != NTB_DEF_PEER_IDX)
		return -EINVAL;

	bar = ndev_mw_to_bar(ndev, idx);
	if (bar < 0)
		return bar;

	mw_size = pci_resource_len(ntb->pdev, bar);

	/* make sure the range fits in the usable mw size */
	if (size > mw_size)
		return -EINVAL;

	mmio = ndev->self_mmio;
	peer_mmio = ndev->peer_mmio;

	base_addr = pci_resource_start(ntb->pdev, bar);

	if (bar != 1) {
		xlat_reg = AMD_BAR23XLAT_OFFSET + ((bar - 2) << 2);
		limit_reg = AMD_BAR23LMT_OFFSET + ((bar - 2) << 2);

		/* Set the limit if supported */
		limit = size;

		/* set and verify setting the translation address */
		write64(addr, peer_mmio + xlat_reg);
		reg_val = read64(peer_mmio + xlat_reg);
		if (reg_val != addr) {
			write64(0, peer_mmio + xlat_reg);
			return -EIO;
		}

		/* set and verify setting the limit */
		write64(limit, peer_mmio + limit_reg);
		reg_val = read64(peer_mmio + limit_reg);
		if (reg_val != limit) {
			write64(base_addr, mmio + limit_reg);
			write64(0, peer_mmio + xlat_reg);
			return -EIO;
		}
	} else {
		xlat_reg = AMD_BAR1XLAT_OFFSET;
		limit_reg = AMD_BAR1LMT_OFFSET;

		/* Set the limit if supported */
		limit = size;

		/* set and verify setting the translation address */
		write64(addr, peer_mmio + xlat_reg);
		reg_val = read64(peer_mmio + xlat_reg);
		if (reg_val != addr) {
			write64(0, peer_mmio + xlat_reg);
			return -EIO;
		}

		/* set and verify setting the limit */
		writel(limit, peer_mmio + limit_reg);
		reg_val = readl(peer_mmio + limit_reg);
		if (reg_val != limit) {
			writel(base_addr, mmio + limit_reg);
			writel(0, peer_mmio + xlat_reg);
			return -EIO;
		}
	}

	return 0;
}

static int amd_link_is_up(struct amd_ntb_dev *ndev)
{
	if (!ndev->peer_sta)