NTB: Add support for AMD PCI-Express Non-Transparent Bridge

This adds support for AMD's PCI-Express Non-Transparent Bridge
(NTB) device on the Zeppelin platform. The driver connnects to the
standard NTB sub-system interface, with modification to add hooks
for power management in a separate patch. The AMD NTB device has 3
memory windows, 16 doorbell, 16 scratch-pad registers, and supports
up to 16 PCIe lanes running a Gen3 speeds.

Signed-off-by: Xiangliang Yu <Xiangliang.Yu@amd.com>
Reviewed-by: Allen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

MAINTAINERS

@@ -7586,6 +7586,12 @@ W:	https://github.com/jonmason/ntb/wiki
 T:	git git://github.com/jonmason/ntb.git
 F:	drivers/ntb/hw/intel/
 
+NTB AMD DRIVER
+M:	Xiangliang Yu <Xiangliang.Yu@amd.com>
+L:	linux-ntb@googlegroups.com
+S:	Supported
+F:	drivers/ntb/hw/amd/
+
 NTFS FILESYSTEM
 M:	Anton Altaparmakov <anton@tuxera.com>
 L:	linux-ntfs-dev@lists.sourceforge.net

drivers/ntb/hw/Kconfig

@@ -1 +1,2 @@
+source "drivers/ntb/hw/amd/Kconfig"
 source "drivers/ntb/hw/intel/Kconfig"

drivers/ntb/hw/Makefile

@@ -1 +1,2 @@
+obj-$(CONFIG_NTB_AMD)	+= amd/
 obj-$(CONFIG_NTB_INTEL)	+= intel/

drivers/ntb/hw/amd/Kconfig

@@ -0,0 +1,7 @@
+config NTB_AMD
+	tristate "AMD Non-Transparent Bridge support"
+	depends on X86_64
+	help
+	 This driver supports AMD NTB on capable Zeppelin hardware.
+
+	 If unsure, say N.

drivers/ntb/hw/amd/Makefile

@@ -0,0 +1 @@
+obj-$(CONFIG_NTB_AMD) += ntb_hw_amd.o

drivers/ntb/hw/amd/ntb_hw_amd.h

@@ -0,0 +1,217 @@
+/*
+ * 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.
+ *
+ *   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.
+ *
+ *   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>
+ */
+
+#ifndef NTB_HW_AMD_H
+#define NTB_HW_AMD_H
+
+#include <linux/ntb.h>
+#include <linux/pci.h>
+
+#define PCI_DEVICE_ID_AMD_NTB	0x145B
+#define AMD_LINK_HB_TIMEOUT	msecs_to_jiffies(1000)
+#define AMD_LINK_STATUS_OFFSET	0x68
+#define NTB_LIN_STA_ACTIVE_BIT	0x00000002
+#define NTB_LNK_STA_SPEED_MASK	0x000F0000
+#define NTB_LNK_STA_WIDTH_MASK	0x03F00000
+#define NTB_LNK_STA_ACTIVE(x)	(!!((x) & NTB_LIN_STA_ACTIVE_BIT))
+#define NTB_LNK_STA_SPEED(x)	(((x) & NTB_LNK_STA_SPEED_MASK) >> 16)
+#define NTB_LNK_STA_WIDTH(x)	(((x) & NTB_LNK_STA_WIDTH_MASK) >> 20)
+
+#ifndef read64
+#ifdef readq
+#define read64 readq
+#else
+#define read64 _read64
+static inline u64 _read64(void __iomem *mmio)
+{
+	u64 low, high;
+
+	low = readl(mmio);
+	high = readl(mmio + sizeof(u32));
+	return low | (high << 32);
+}
+#endif
+#endif
+
+#ifndef write64
+#ifdef writeq
+#define write64 writeq
+#else
+#define write64 _write64
+static inline void _write64(u64 val, void __iomem *mmio)
+{
+	writel(val, mmio);
+	writel(val >> 32, mmio + sizeof(u32));
+}
+#endif
+#endif
+
+enum {
+	/* AMD NTB Capability */
+	AMD_MW_CNT		= 3,
+	AMD_DB_CNT		= 16,
+	AMD_MSIX_VECTOR_CNT	= 24,
+	AMD_SPADS_CNT		= 16,
+
+	/*  AMD NTB register offset */
+	AMD_CNTL_OFFSET		= 0x200,
+
+	/* NTB control register bits */
+	PMM_REG_CTL		= BIT(21),
+	SMM_REG_CTL		= BIT(20),
+	SMM_REG_ACC_PATH	= BIT(18),
+	PMM_REG_ACC_PATH	= BIT(17),
+	NTB_CLK_EN		= BIT(16),
+
+	AMD_STA_OFFSET		= 0x204,
+	AMD_PGSLV_OFFSET	= 0x208,
+	AMD_SPAD_MUX_OFFSET	= 0x20C,
+	AMD_SPAD_OFFSET		= 0x210,
+	AMD_RSMU_HCID		= 0x250,
+	AMD_RSMU_SIID		= 0x254,
+	AMD_PSION_OFFSET	= 0x300,
+	AMD_SSION_OFFSET	= 0x330,
+	AMD_MMINDEX_OFFSET	= 0x400,
+	AMD_MMDATA_OFFSET	= 0x404,
+	AMD_SIDEINFO_OFFSET	= 0x408,
+
+	AMD_SIDE_MASK		= BIT(0),
+	AMD_SIDE_READY		= BIT(1),
+
+	/* limit register */
+	AMD_ROMBARLMT_OFFSET	= 0x410,
+	AMD_BAR1LMT_OFFSET	= 0x414,
+	AMD_BAR23LMT_OFFSET	= 0x418,
+	AMD_BAR45LMT_OFFSET	= 0x420,
+	/* xlat address */
+	AMD_POMBARXLAT_OFFSET	= 0x428,
+	AMD_BAR1XLAT_OFFSET	= 0x430,
+	AMD_BAR23XLAT_OFFSET	= 0x438,
+	AMD_BAR45XLAT_OFFSET	= 0x440,
+	/* doorbell and interrupt */
+	AMD_DBFM_OFFSET		= 0x450,
+	AMD_DBREQ_OFFSET	= 0x454,
+	AMD_MIRRDBSTAT_OFFSET	= 0x458,
+	AMD_DBMASK_OFFSET	= 0x45C,
+	AMD_DBSTAT_OFFSET	= 0x460,
+	AMD_INTMASK_OFFSET	= 0x470,
+	AMD_INTSTAT_OFFSET	= 0x474,
+
+	/* event type */
+	AMD_PEER_FLUSH_EVENT	= BIT(0),
+	AMD_PEER_RESET_EVENT	= BIT(1),
+	AMD_PEER_D3_EVENT	= BIT(2),
+	AMD_PEER_PMETO_EVENT	= BIT(3),
+	AMD_PEER_D0_EVENT	= BIT(4),
+	AMD_EVENT_INTMASK	= (AMD_PEER_FLUSH_EVENT |
+				AMD_PEER_RESET_EVENT | AMD_PEER_D3_EVENT |
+				AMD_PEER_PMETO_EVENT | AMD_PEER_D0_EVENT),
+
+	AMD_PMESTAT_OFFSET	= 0x480,
+	AMD_PMSGTRIG_OFFSET	= 0x490,
+	AMD_LTRLATENCY_OFFSET	= 0x494,
+	AMD_FLUSHTRIG_OFFSET	= 0x498,
+
+	/* SMU register*/
+	AMD_SMUACK_OFFSET	= 0x4A0,
+	AMD_SINRST_OFFSET	= 0x4A4,
+	AMD_RSPNUM_OFFSET	= 0x4A8,
+	AMD_SMU_SPADMUTEX	= 0x4B0,
+	AMD_SMU_SPADOFFSET	= 0x4B4,
+
+	AMD_PEER_OFFSET		= 0x400,
+};
+
+struct amd_ntb_dev;
+
+struct amd_ntb_vec {
+	struct amd_ntb_dev	*ndev;
+	int			num;
+};
+
+struct amd_ntb_dev {
+	struct ntb_dev ntb;
+
+	u32 ntb_side;
+	u32 lnk_sta;
+	u32 cntl_sta;
+	u32 peer_sta;
+
+	unsigned char mw_count;
+	unsigned char spad_count;
+	unsigned char db_count;
+	unsigned char msix_vec_count;
+
+	u64 db_valid_mask;
+	u64 db_mask;
+	u32 int_mask;
+
+	struct msix_entry *msix;
+	struct amd_ntb_vec *vec;
+
+	/* synchronize rmw access of db_mask and hw reg */
+	spinlock_t db_mask_lock;
+
+	void __iomem *self_mmio;
+	void __iomem *peer_mmio;
+	unsigned int self_spad;
+	unsigned int peer_spad;
+
+	struct delayed_work hb_timer;
+
+	struct dentry *debugfs_dir;
+	struct dentry *debugfs_info;
+};
+
+#define ndev_pdev(ndev) ((ndev)->ntb.pdev)
+#define ndev_name(ndev) pci_name(ndev_pdev(ndev))
+#define ndev_dev(ndev) (&ndev_pdev(ndev)->dev)
+#define ntb_ndev(__ntb) container_of(__ntb, struct amd_ntb_dev, ntb)
+#define hb_ndev(__work) container_of(__work, struct amd_ntb_dev, hb_timer.work)
+
+#endif