RE: [PATCH V3 1/2] NTB: Add AMD PCI-Express NTB driver

From: Yu, Xiangliang
Date: Mon Jan 18 2016 - 04:43:12 EST


> On Thu, Jan 14, 2016 at 07:44:07PM +0800, Xiangliang Yu wrote:
> > AMD NTB support following main features:
> > (1) Three memory windows;
> > (2) Sixteen 32-bit scratch pad;
> > (3) Two 16-bit doorbell interrupt;
> > (4) Five event interrupts;
> > (5) One system can wake up opposite system of NTB;
> > (6) Flush previous request to the opposite system;
> > (7) There are reset and PME_TO mechanisms between two systems;
>
> Please create a much more verbose description of the patch. This is not
> acceptable in it's current form, and I'm sure I could get flamed by Linus if he
> saw it in my pull request. Even writing this out as a paragaph instead of a
> numbered list would be better.

Ok, I'll change it.

> >
> > Signed-off-by: Xiangliang Yu <Xiangliang.Yu@xxxxxxx>
> > ---
> > drivers/ntb/hw/Kconfig | 1 +
> > drivers/ntb/hw/Makefile | 1 +
> > drivers/ntb/hw/amd/Kconfig | 7 +
> > drivers/ntb/hw/amd/Makefile | 1 +
> > drivers/ntb/hw/amd/ntb_hw_amd.c | 1148
> > +++++++++++++++++++++++++++++++++++++++
> > drivers/ntb/hw/amd/ntb_hw_amd.h | 246 +++++++++
> > 6 files changed, 1404 insertions(+)
> > create mode 100644 drivers/ntb/hw/amd/Kconfig create mode 100644
> > drivers/ntb/hw/amd/Makefile create mode 100644
> > drivers/ntb/hw/amd/ntb_hw_amd.c create mode 100644
> > drivers/ntb/hw/amd/ntb_hw_amd.h
> >
> > diff --git a/drivers/ntb/hw/Kconfig b/drivers/ntb/hw/Kconfig index
> > 4d5535c..0c5c2a6 100644
> > --- a/drivers/ntb/hw/Kconfig
> > +++ b/drivers/ntb/hw/Kconfig
> > @@ -1 +1,2 @@
> > source "drivers/ntb/hw/intel/Kconfig"
> > +source "drivers/ntb/hw/amd/Kconfig"
>
> Being nit picky, but please make it alphabetical and put amd before intel.

Ok.

> > diff --git a/drivers/ntb/hw/Makefile b/drivers/ntb/hw/Makefile index
> > 175d7c9..636be7d 100644
> > --- a/drivers/ntb/hw/Makefile
> > +++ b/drivers/ntb/hw/Makefile
> > @@ -1 +1,2 @@
> > obj-$(CONFIG_NTB_INTEL) += intel/
> > +obj-$(CONFIG_NTB_AMD) += amd/
>
> Same nit, make it alphabetical.

Ok.

> > diff --git a/drivers/ntb/hw/amd/Kconfig b/drivers/ntb/hw/amd/Kconfig
> > new file mode 100644 index 0000000..cfe903c
> > --- /dev/null
> > +++ b/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.
> > diff --git a/drivers/ntb/hw/amd/Makefile b/drivers/ntb/hw/amd/Makefile
> > new file mode 100644 index 0000000..ad54da9
> > --- /dev/null
> > +++ b/drivers/ntb/hw/amd/Makefile
> > @@ -0,0 +1 @@
> > +obj-$(CONFIG_NTB_AMD) += ntb_hw_amd.o
> > diff --git a/drivers/ntb/hw/amd/ntb_hw_amd.c
> > b/drivers/ntb/hw/amd/ntb_hw_amd.c new file mode 100644 index
> > 0000000..8df6d7b
> > --- /dev/null
> > +++ b/drivers/ntb/hw/amd/ntb_hw_amd.c
> > @@ -0,0 +1,1148 @@
> > +/*
> > + * 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@xxxxxxx>
>
> Nit, space needed between 'u' and '<'

Ok

> > + */
> > +
> > +#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 const struct ntb_dev_ops amd_ntb_ops = {
> > + .mw_count = amd_ntb_mw_count,
> > + .mw_get_range = amd_ntb_mw_get_range,
> > + .mw_set_trans = amd_ntb_mw_set_trans,
> > + .link_is_up = amd_ntb_link_is_up,
> > + .link_enable = amd_ntb_link_enable,
> > + .link_disable = amd_ntb_link_disable,
> > + .db_valid_mask = amd_ntb_db_valid_mask,
> > + .db_vector_count = amd_ntb_db_vector_count,
> > + .db_vector_mask = amd_ntb_db_vector_mask,
> > + .db_read = amd_ntb_db_read,
> > + .db_clear = amd_ntb_db_clear,
> > + .db_set_mask = amd_ntb_db_set_mask,
> > + .db_clear_mask = amd_ntb_db_clear_mask,
> > + .peer_db_addr = amd_ntb_peer_db_addr,
> > + .peer_db_set = amd_ntb_peer_db_set,
> > + .spad_count = amd_ntb_spad_count,
> > + .spad_read = amd_ntb_spad_read,
> > + .spad_write = amd_ntb_spad_write,
> > + .peer_spad_addr = amd_ntb_peer_spad_addr,
> > + .peer_spad_read = amd_ntb_peer_spad_read,
> > + .peer_spad_write = amd_ntb_peer_spad_write,
> > +};
> > +
> > +static int ndev_mw_to_bar(struct amd_ntb_dev *ndev, int idx) {
> > + if (idx < 0 || idx > ndev->mw_count)
> > + return -EINVAL;
> > +
> > + return 1 << idx;
> > +}
> > +
> > +static int amd_ntb_mw_count(struct ntb_dev *ntb) {
> > + return ntb_ndev(ntb)->mw_count;
> > +}
> > +
> > +static int amd_ntb_mw_get_range(struct ntb_dev *ntb, int idx,
> > + phys_addr_t *base,
> > + resource_size_t *size,
> > + resource_size_t *align,
> > + resource_size_t *align_size)
> > +{
> > + struct amd_ntb_dev *ndev = ntb_ndev(ntb);
> > + int bar;
> > +
> > + bar = ndev_mw_to_bar(ndev, idx);
> > + if (bar < 0)
> > + return bar;
> > +
> > + if (base)
> > + *base = pci_resource_start(ndev->ntb.pdev, bar);
> > +
> > + if (size)
> > + *size = pci_resource_len(ndev->ntb.pdev, bar);
> > +
> > + if (align)
> > + *align = 4096;
>
> Please use SZ_4K from sizes.h

Ok

> > +
> > + if (align_size)
> > + *align_size = 1;
> > +
> > + return 0;
> > +}
> > +
> > +static int amd_ntb_mw_set_trans(struct ntb_dev *ntb, 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;
> > +
> > + bar = ndev_mw_to_bar(ndev, idx);
> > + if (bar < 0)
> > + return bar;
> > +
> > + mw_size = pci_resource_len(ndev->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(ndev->ntb.pdev, bar);
> > + if (bar == 1) {
> > + xlat_reg = AMD_BAR1XLAT_OFFSET;
> > + limit_reg = AMD_BAR1LMT_OFFSET;
> > + } else {
> > + xlat_reg = AMD_BAR23XLAT_OFFSET + ((bar - 2) << 3);
> > + limit_reg = AMD_BAR23LMT_OFFSET + ((bar - 2) << 3);
> > + }
> > +
> > + if (bar != 1) {
> > + /* Set the limit if supported */
> > + limit = base_addr + size;
> > +
> > + /* set and verify setting the translation address */
> > + iowrite64(addr, peer_mmio + xlat_reg);
> > + reg_val = ioread64(peer_mmio + xlat_reg);
> > + if (reg_val != addr) {
> > + iowrite64(0, peer_mmio + xlat_reg);
> > + return -EIO;
> > + }
> > +
> > + /* set and verify setting the limit */
> > + iowrite64(limit, mmio + limit_reg);
> > + reg_val = ioread64(mmio + limit_reg);
> > + if (reg_val != limit) {
> > + iowrite64(base_addr, mmio + limit_reg);
> > + iowrite64(0, peer_mmio + xlat_reg);
> > + return -EIO;
> > + }
> > + } else {
> > + /* split bar addr range must all be 32 bit */
> > + if (addr & (~0ull << 32))
> > + return -EINVAL;
> > + if ((addr + size) & (~0ull << 32))
> > + return -EINVAL;
> > +
> > + /* Set the limit if supported */
> > + limit = base_addr + size;
> > +
> > + /* set and verify setting the translation address */
> > + iowrite64(addr, peer_mmio + xlat_reg);
> > + reg_val = ioread64(peer_mmio + xlat_reg);
> > + if (reg_val != addr) {
> > + iowrite64(0, peer_mmio + xlat_reg);
> > + return -EIO;
> > + }
> > +
> > + /* set and verify setting the limit */
> > + writel(limit, mmio + limit_reg);
> > + reg_val = readl(mmio + limit_reg);
> > + if (reg_val != limit) {
> > + writel(base_addr, mmio + limit_reg);
> > + writel(0, peer_mmio + xlat_reg);
> > + return -EIO;
> > + }
> > + }
>
> Being nit picky here again, but why is it necessary to make 2 consecutive
> checks for the same 'bar' variable. Please combine them.

Ok.

> > +
> > + return 0;
> > +}
> > +
> > +static int amd_link_is_up(struct amd_ntb_dev *ndev) {
> > + /* set link down and clear flag */
> > + if (ndev->peer_sta & AMD_PEER_RESET_EVENT) {
> > + ndev->peer_sta &= ~AMD_PEER_RESET_EVENT;
> > + return 0;
> > + } else if (ndev->peer_sta & (AMD_PEER_D3_EVENT |
> > + AMD_PEER_PMETO_EVENT)) {
> > + return 0;
> > + } else if (ndev->peer_sta & AMD_PEER_D0_EVENT) {
> > + ndev->peer_sta = 0;
> > + return 0;
> > + } else
> > + return NTB_LNK_STA_ACTIVE(ndev->cntl_sta);
> > +}
> > +
> > +static int amd_ntb_link_is_up(struct ntb_dev *ntb,
> > + enum ntb_speed *speed,
> > + enum ntb_width *width)
> > +{
> > + struct amd_ntb_dev *ndev = ntb_ndev(ntb);
> > + int ret = 0;
> > +
> > + if (amd_link_is_up(ndev)) {
> > + if (speed)
> > + *speed = NTB_LNK_STA_SPEED(ndev->lnk_sta);
> > + if (width)
> > + *width = NTB_LNK_STA_WIDTH(ndev->lnk_sta);
> > +
> > + dev_dbg(ndev_dev(ndev), "link is up.\n");
> > +
> > + ret = 1;
> > + } else {
> > + if (speed)
> > + *speed = NTB_SPEED_NONE;
> > + if (width)
> > + *width = NTB_WIDTH_NONE;
> > +
> > + dev_dbg(ndev_dev(ndev), "link is down.\n");
> > + }
> > +
> > + return ret;
> > +}
> > +
> > +static int amd_ntb_link_enable(struct ntb_dev *ntb,
> > + enum ntb_speed max_speed,
> > + enum ntb_width max_width)
> > +{
> > + struct amd_ntb_dev *ndev = ntb_ndev(ntb);
> > + void __iomem *mmio = ndev->self_mmio;
> > + u32 ntb_ctl;
> > +
> > + /* Enable event interrupt */
> > + ndev->int_mask &= ~AMD_EVENT_INTMASK;
> > + writel(ndev->int_mask, mmio + AMD_INTMASK_OFFSET);
> > +
> > + if (ndev->ntb.topo == NTB_TOPO_SEC)
> > + return -EINVAL;
> > + dev_dbg(ndev_dev(ndev), "Enabling Link.\n");
> > +
> > + ntb_ctl = readl(mmio + AMD_CNTL_OFFSET);
> > + ntb_ctl |= (3 << 20);
>
> This "20" is a bit magical to me. Please use a #define

Yes.

> > + writel(ntb_ctl, mmio + AMD_CNTL_OFFSET);
> > +
> > + return 0;
> > +}
> > +
> > +static int amd_ntb_link_disable(struct ntb_dev *ntb) {
> > + struct amd_ntb_dev *ndev = ntb_ndev(ntb);
> > + void __iomem *mmio = ndev->self_mmio;
> > + u32 ntb_ctl;
> > +
> > + /* Disable event interrupt */
> > + ndev->int_mask |= AMD_EVENT_INTMASK;
> > + writel(ndev->int_mask, mmio + AMD_INTMASK_OFFSET);
> > +
> > + if (ndev->ntb.topo == NTB_TOPO_SEC)
> > + return -EINVAL;
> > + dev_dbg(ndev_dev(ndev), "Enabling Link.\n");
> > +
> > + ntb_ctl = readl(mmio + AMD_CNTL_OFFSET);
> > + ntb_ctl &= ~(3 << 16);
>
> Should this be "20" or "16"? Seems odd that you would use a different offset
> to enable than disable. Either way, a #define here would be nice too.

Got it.

> > + writel(ntb_ctl, mmio + AMD_CNTL_OFFSET);
> > +
> > + return 0;
> > +}
> > +
> > +static u64 amd_ntb_db_valid_mask(struct ntb_dev *ntb) {
> > + return ntb_ndev(ntb)->db_valid_mask; }
> > +
> > +static int amd_ntb_db_vector_count(struct ntb_dev *ntb) {
> > + return ntb_ndev(ntb)->db_count;
> > +}
> > +
> > +static u64 amd_ntb_db_vector_mask(struct ntb_dev *ntb, int db_vector)
> > +{
> > + struct amd_ntb_dev *ndev = ntb_ndev(ntb);
> > +
> > + if (db_vector < 0 || db_vector > ndev->db_count)
> > + return 0;
> > +
> > + return ntb_ndev(ntb)->db_valid_mask & (1 << db_vector); }
> > +
> > +static u64 amd_ntb_db_read(struct ntb_dev *ntb) {
> > + struct amd_ntb_dev *ndev = ntb_ndev(ntb);
> > + void __iomem *mmio = ndev->self_mmio;
> > +
> > + return (u64)readw(mmio + AMD_DBSTAT_OFFSET);
>
> Is this cast necessary?

Just following Intel ntb driver, keep consistent in Intel code.

>
> > +}
> > +
> > +static int amd_ntb_db_clear(struct ntb_dev *ntb, u64 db_bits) {
> > + struct amd_ntb_dev *ndev = ntb_ndev(ntb);
> > + void __iomem *mmio = ndev->self_mmio;
> > +
> > + writew((u16)db_bits, mmio + AMD_DBSTAT_OFFSET);
> > +
> > + return 0;
> > +}
> > +
> > +static int amd_ntb_db_set_mask(struct ntb_dev *ntb, u64 db_bits) {
> > + struct amd_ntb_dev *ndev = ntb_ndev(ntb);
> > + void __iomem *mmio = ndev->self_mmio;
> > + unsigned long flags;
> > +
> > + if (db_bits & ~ndev->db_valid_mask)
> > + return -EINVAL;
> > +
> > + spin_lock_irqsave(&ndev->db_mask_lock, flags);
> > + ndev->db_mask |= db_bits;
> > + writew((u16)ndev->db_mask, mmio + AMD_DBMASK_OFFSET);
> > + spin_unlock_irqrestore(&ndev->db_mask_lock, flags);
> > +
> > + return 0;
> > +}
> > +
> > +static int amd_ntb_db_clear_mask(struct ntb_dev *ntb, u64 db_bits) {
> > + struct amd_ntb_dev *ndev = ntb_ndev(ntb);
> > + void __iomem *mmio = ndev->self_mmio;
> > + unsigned long flags;
> > +
> > + if (db_bits & ~ndev->db_valid_mask)
> > + return -EINVAL;
> > +
> > + spin_lock_irqsave(&ndev->db_mask_lock, flags);
> > + ndev->db_mask &= ~db_bits;
> > + writew((u16)ndev->db_mask, mmio + AMD_DBMASK_OFFSET);
> > + spin_unlock_irqrestore(&ndev->db_mask_lock, flags);
> > +
> > + return 0;
> > +}
> > +
> > +static int amd_ntb_peer_db_addr(struct ntb_dev *ntb,
> > + phys_addr_t *db_addr,
> > + resource_size_t *db_size)
>
> Nit, this doesn't seem like it would be aligned properly.

Got it.

> > +{
> > + struct amd_ntb_dev *ndev = ntb_ndev(ntb);
> > +
> > + if (db_addr)
> > + *db_addr = (phys_addr_t)(ndev->peer_mmio +
> AMD_DBREQ_OFFSET);
> > + if (db_size)
> > + *db_size = sizeof(u32);
> > +
> > + return 0;
> > +}
> > +
> > +static int amd_ntb_peer_db_set(struct ntb_dev *ntb, u64 db_bits) {
> > + struct amd_ntb_dev *ndev = ntb_ndev(ntb);
> > + void __iomem *mmio = ndev->self_mmio;
> > +
> > + writew((u16)db_bits, mmio + AMD_DBREQ_OFFSET);
> > +
> > + return 0;
> > +}
> > +
> > +static int amd_ntb_spad_count(struct ntb_dev *ntb) {
> > + return ntb_ndev(ntb)->spad_count;
> > +}
> > +
> > +static u32 amd_ntb_spad_read(struct ntb_dev *ntb, int idx) {
> > + struct amd_ntb_dev *ndev = ntb_ndev(ntb);
> > + void __iomem *mmio = ndev->self_mmio;
> > + u32 offset = 0;
>
> Unnecessary init of this variable

Ok.

> > +
> > + if (idx < 0 || idx >= ndev->spad_count)
> > + return 0;
> > +
> > + offset = ndev->self_spad + (idx << 2);
> > + return readl(mmio + AMD_SPAD_OFFSET + offset); }
> > +
> > +static int amd_ntb_spad_write(struct ntb_dev *ntb,
> > + int idx, u32 val)
> > +{
> > + struct amd_ntb_dev *ndev = ntb_ndev(ntb);
> > + void __iomem *mmio = ndev->self_mmio;
> > + u32 offset = 0;
>
> Unnecessary init of this variable

Ok.

> > +
> > + if (idx < 0 || idx >= ndev->spad_count)
> > + return -EINVAL;
> > +
> > + offset = ndev->self_spad + (idx << 2);
> > + writel(val, mmio + AMD_SPAD_OFFSET + offset);
> > +
> > + return 0;
> > +}
> > +
> > +static int amd_ntb_peer_spad_addr(struct ntb_dev *ntb, int idx,
> > + phys_addr_t *spad_addr)
> > +{
> > + struct amd_ntb_dev *ndev = ntb_ndev(ntb);
> > +
> > + if (idx < 0 || idx >= ndev->spad_count)
> > + return -EINVAL;
> > +
> > + if (spad_addr)
> > + *spad_addr = (phys_addr_t)(ndev->self_mmio +
> AMD_SPAD_OFFSET +
> > + ndev->peer_spad + (idx << 2));
>
> This doesn't seem aligned properly either.

Ok

> > + return 0;
> > +}
> > +
> > +static u32 amd_ntb_peer_spad_read(struct ntb_dev *ntb, int idx) {
> > + struct amd_ntb_dev *ndev = ntb_ndev(ntb);
> > + void __iomem *mmio = ndev->self_mmio;
> > + u32 offset;
> > +
> > + if (idx < 0 || idx >= ndev->spad_count)
> > + return -EINVAL;
> > +
> > + offset = ndev->peer_spad + (idx << 2);
> > + return readl(mmio + AMD_SPAD_OFFSET + offset); }
> > +
> > +static int amd_ntb_peer_spad_write(struct ntb_dev *ntb,
> > + int idx, u32 val)
> > +{
> > + struct amd_ntb_dev *ndev = ntb_ndev(ntb);
> > + void __iomem *mmio = ndev->self_mmio;
> > + u32 offset;
> > +
> > + if (idx < 0 || idx >= ndev->spad_count)
> > + return -EINVAL;
> > +
> > + offset = ndev->peer_spad + (idx << 2);
> > + writel(val, mmio + AMD_SPAD_OFFSET + offset);
> > +
> > + return 0;
> > +}
> > +
> > +static void amd_ack_SMU(struct amd_ntb_dev *ndev, u32 bit)
>
> Nit, Please make this SMU lower case. Also, it is a bit odd to see SMUACK
> and ack_smu. It is not a big deal, but since there has to be another version to
> address Allen's comments (and mine), then this won't add to much additional
> work to address.

Ok.

> > +{
> > + void __iomem *mmio = ndev->self_mmio;
> > + int reg;
> > +
> > + reg = readl(mmio + AMD_SMUACK_OFFSET);
> > + reg |= bit;
> > + writel(reg, mmio + AMD_SMUACK_OFFSET);
> > +
> > + ndev->peer_sta |= bit;
> > +}
> > +
> > +static void amd_handle_event(struct amd_ntb_dev *ndev, int vec) {
> > + void __iomem *mmio = ndev->self_mmio;
> > + u32 status;
> > +
> > + status = readl(mmio + AMD_INTSTAT_OFFSET);
> > + if (!(status & AMD_EVENT_INTMASK))
> > + return;
> > +
> > + dev_dbg(ndev_dev(ndev), "status = 0x%x and vec = %d\n", status,
> > +vec);
> > +
> > + status &= AMD_EVENT_INTMASK;
> > + switch (status) {
> > + case AMD_PEER_FLUSH_EVENT:
> > + dev_info(ndev_dev(ndev), "Flush is done.\n");
> > + break;
> > + case AMD_PEER_RESET_EVENT:
> > + amd_ack_SMU(ndev, AMD_PEER_RESET_EVENT);
> > +
> > + /* link down first */
> > + ntb_link_event(&ndev->ntb);
> > + /* polling peer status */
> > + schedule_delayed_work(&ndev->hb_timer,
> AMD_LINK_HB_TIMEOUT);
> > +
> > + break;
> > + case AMD_PEER_D3_EVENT:
> > + case AMD_PEER_PMETO_EVENT:
> > + amd_ack_SMU(ndev, status);
> > +
> > + /* link down */
> > + ntb_link_event(&ndev->ntb);
> > +
> > + break;
> > + case AMD_PEER_D0_EVENT:
> > + mmio = ndev->peer_mmio;
> > + status = readl(mmio + AMD_PMESTAT_OFFSET);
> > + /* check if this is WAKEUP event */
> > + if (status & 0x1)
> > + dev_info(ndev_dev(ndev), "Wakeup is done.\n");
> > +
> > + amd_ack_SMU(ndev, AMD_PEER_D0_EVENT);
> > +
> > + if (amd_link_is_up(ndev))
> > + ntb_link_event(&ndev->ntb);
> > + else
> > + schedule_delayed_work(&ndev->hb_timer,
> > + AMD_LINK_HB_TIMEOUT);
> > + break;
> > + default:
> > + dev_info(ndev_dev(ndev), "event status = 0x%x.\n", status);
> > + break;
> > + }
> > +}
> > +
> > +static irqreturn_t ndev_interrupt(struct amd_ntb_dev *ndev, int vec)
> > +{
> > + dev_dbg(ndev_dev(ndev), "vec %d\n", vec);
> > +
> > + if (vec > (ndev->msix_vec_count - 1)) {
> > + dev_err(ndev_dev(ndev), "Invalid interrupt.\n");
> > + return IRQ_HANDLED;
> > + }
>
> Unless this actually happens, you might not want the unnecessary branch in
> your fast path.

Ok, I'll remove it.

> > +
> > + if (vec > 15 || (ndev->msix_vec_count == 1))
> > + amd_handle_event(ndev, vec);
> > +
> > + if (vec < 16)
>
> I'd prefer to see a #define here for 16

Ok.

>
> > + ntb_db_event(&ndev->ntb, vec);
> > +
> > + return IRQ_HANDLED;
> > +}
> > +
> > +static irqreturn_t ndev_vec_isr(int irq, void *dev) {
> > + struct amd_ntb_vec *nvec = dev;
> > +
> > + return ndev_interrupt(nvec->ndev, nvec->num); }
> > +
> > +static irqreturn_t ndev_irq_isr(int irq, void *dev) {
> > + struct amd_ntb_dev *ndev = dev;
> > +
> > + return ndev_interrupt(ndev, irq - ndev_pdev(ndev)->irq); }
> > +
> > +static int ndev_init_isr(struct amd_ntb_dev *ndev,
> > + int msix_min, int msix_max)
> > +{
> > + struct pci_dev *pdev;
> > + int rc, i, msix_count, node;
> > +
> > + pdev = ndev_pdev(ndev);
> > +
> > + node = dev_to_node(&pdev->dev);
> > +
> > + ndev->db_mask = ndev->db_valid_mask;
> > +
> > + /* Try to set up msix irq */
> > + ndev->vec = kzalloc_node(msix_max * sizeof(*ndev->vec),
> > + GFP_KERNEL, node);
> > + if (!ndev->vec)
> > + goto err_msix_vec_alloc;
> > +
> > + ndev->msix = kzalloc_node(msix_max * sizeof(*ndev->msix),
> > + GFP_KERNEL, node);
> > + if (!ndev->msix)
> > + goto err_msix_alloc;
> > +
> > + for (i = 0; i < msix_max; ++i)
> > + ndev->msix[i].entry = i;
> > +
> > + msix_count = pci_enable_msix_range(pdev, ndev->msix,
> > + msix_min, msix_max);
> > + if (msix_count < 0)
> > + goto err_msix_enable;
> > +
> > + /* Disable MSIX if msix count is less than 16 */
>
> Why? Is there a HW errata or limitation (if so, write so in this comment)? If
> not, MSIX has many benefits over legacy interrupts, and it doesn't make
> sense to walk away from that.

Yes, this is hardware limitation, i'll add "hardware limitation" into the comment.

>
> > + if (msix_count < msix_min) {
> > + pci_disable_msix(pdev);
> > + goto err_msix_enable;
> > + }
> > +
> > + for (i = 0; i < msix_count; ++i) {
> > + ndev->vec[i].ndev = ndev;
> > + ndev->vec[i].num = i;
> > + rc = request_irq(ndev->msix[i].vector, ndev_vec_isr, 0,
> > + "ndev_vec_isr", &ndev->vec[i]);
> > + if (rc)
> > + goto err_msix_request;
> > + }
> > +
> > + dev_dbg(ndev_dev(ndev), "Using msix interrupts\n");
> > + ndev->db_count = msix_min;
> > + ndev->msix_vec_count = msix_max;
> > + return 0;
> > +
> > +err_msix_request:
> > + while (i-- > 0)
> > + free_irq(ndev->msix[i].vector, ndev);
> > + pci_disable_msix(pdev);
> > +err_msix_enable:
> > + kfree(ndev->msix);
> > +err_msix_alloc:
> > + kfree(ndev->vec);
> > +err_msix_vec_alloc:
> > + ndev->msix = NULL;
> > + ndev->vec = NULL;
> > +
> > + /* Try to set up msi irq */
> > + rc = pci_enable_msi(pdev);
> > + if (rc)
> > + goto err_msi_enable;
> > +
> > + rc = request_irq(pdev->irq, ndev_irq_isr, 0,
> > + "ndev_irq_isr", ndev);
> > + if (rc)
> > + goto err_msi_request;
> > +
>
> I have problems with the msix/msi/intx selection being done this way, but I
> see it being done in the Intel driver. So....I'll fix it there first.

Ok, I'll change it according to your patch.

>
> > + dev_dbg(ndev_dev(ndev), "Using msi interrupts\n");
> > + ndev->db_count = 1;
> > + ndev->msix_vec_count = 1;
> > + return 0;
> > +
> > +err_msi_request:
> > + pci_disable_msi(pdev);
> > +err_msi_enable:
> > +
> > + /* Try to set up intx irq */
> > + pci_intx(pdev, 1);
> > +
> > + rc = request_irq(pdev->irq, ndev_irq_isr, IRQF_SHARED,
> > + "ndev_irq_isr", ndev);
> > + if (rc)
> > + goto err_intx_request;
> > +
> > + dev_dbg(ndev_dev(ndev), "Using intx interrupts\n");
> > + ndev->db_count = 1;
> > + ndev->msix_vec_count = 1;
> > + return 0;
> > +
> > +err_intx_request:
> > + return rc;
> > +}
> > +
> > +static void ndev_deinit_isr(struct amd_ntb_dev *ndev) {
> > + struct pci_dev *pdev;
> > + void __iomem *mmio = ndev->self_mmio;
> > + int i;
> > +
> > + pdev = ndev_pdev(ndev);
> > +
> > + /* Mask all doorbell interrupts */
> > + ndev->db_mask = ndev->db_valid_mask;
> > + writel(ndev->db_mask, mmio + AMD_DBMASK_OFFSET);
> > +
> > + if (ndev->msix) {
> > + i = ndev->msix_vec_count;
> > + while (i--)
> > + free_irq(ndev->msix[i].vector, &ndev->vec[i]);
> > + pci_disable_msix(pdev);
> > + kfree(ndev->msix);
> > + kfree(ndev->vec);
> > + } else {
> > + free_irq(pdev->irq, ndev);
> > + if (pci_dev_msi_enabled(pdev))
> > + pci_disable_msi(pdev);
> > + else
> > + pci_intx(pdev, 0);
> > + }
> > +}
> > +
> > +static ssize_t ndev_debugfs_read(struct file *filp, char __user *ubuf,
> > + size_t count, loff_t *offp)
> > +{
> > + struct amd_ntb_dev *ndev;
> > + void __iomem *mmio;
> > + char *buf;
> > + size_t buf_size;
> > + ssize_t ret, off;
> > + union { u64 v64; u32 v32; u16 v16; } u;
> > +
> > + ndev = filp->private_data;
> > + mmio = ndev->self_mmio;
> > +
> > + buf_size = min(count, 0x800ul);
> > +
> > + buf = kmalloc(buf_size, GFP_KERNEL);
> > + if (!buf)
> > + return -ENOMEM;
> > +
> > + off = 0;
> > +
> > + off += scnprintf(buf + off, buf_size - off,
> > + "NTB Device Information:\n");
> > +
> > + off += scnprintf(buf + off, buf_size - off,
> > + "Connection Topology -\t%s\n",
> > + ntb_topo_string(ndev->ntb.topo));
> > +
> > + off += scnprintf(buf + off, buf_size - off,
> > + "LNK STA -\t\t%#06x\n", ndev->lnk_sta);
> > +
> > + if (!amd_link_is_up(ndev)) {
> > + off += scnprintf(buf + off, buf_size - off,
> > + "Link Status -\t\tDown\n");
> > + } else {
> > + off += scnprintf(buf + off, buf_size - off,
> > + "Link Status -\t\tUp\n");
> > + off += scnprintf(buf + off, buf_size - off,
> > + "Link Speed -\t\tPCI-E Gen %u\n",
> > + NTB_LNK_STA_SPEED(ndev->lnk_sta));
> > + off += scnprintf(buf + off, buf_size - off,
> > + "Link Width -\t\tx%u\n",
> > + NTB_LNK_STA_WIDTH(ndev->lnk_sta));
> > + }
> > +
> > + off += scnprintf(buf + off, buf_size - off,
> > + "Memory Window Count -\t%u\n", ndev-
> >mw_count);
> > + off += scnprintf(buf + off, buf_size - off,
> > + "Scratchpad Count -\t%u\n", ndev->spad_count);
> > + off += scnprintf(buf + off, buf_size - off,
> > + "Doorbell Count -\t%u\n", ndev->db_count);
> > + off += scnprintf(buf + off, buf_size - off,
> > + "MSIX Vector Count -\t%u\n", ndev-
> >msix_vec_count);
> > +
> > + off += scnprintf(buf + off, buf_size - off,
> > + "Doorbell Valid Mask -\t%#llx\n", ndev-
> >db_valid_mask);
> > +
> > + u.v32 = readl(ndev->self_mmio + AMD_DBMASK_OFFSET);
> > + off += scnprintf(buf + off, buf_size - off,
> > + "Doorbell Mask -\t\t\t%#06x\n", u.v32);
> > +
> > + u.v32 = readl(mmio + AMD_DBSTAT_OFFSET);
> > + off += scnprintf(buf + off, buf_size - off,
> > + "Doorbell Bell -\t\t\t%#06x\n", u.v32);
> > +
> > + off += scnprintf(buf + off, buf_size - off,
> > + "\nNTB Incoming XLAT:\n");
> > +
> > + u.v64 = ioread64(mmio + AMD_BAR1XLAT_OFFSET);
> > + off += scnprintf(buf + off, buf_size - off,
> > + "XLAT1 -\t\t%#018llx\n", u.v64);
> > +
> > + u.v64 = ioread64(ndev->self_mmio + AMD_BAR23XLAT_OFFSET);
> > + off += scnprintf(buf + off, buf_size - off,
> > + "XLAT23 -\t\t%#018llx\n", u.v64);
> > +
> > + u.v64 = ioread64(ndev->self_mmio + AMD_BAR45XLAT_OFFSET);
> > + off += scnprintf(buf + off, buf_size - off,
> > + "XLAT45 -\t\t%#018llx\n", u.v64);
> > +
> > + u.v32 = readl(mmio + AMD_BAR1LMT_OFFSET);
> > + off += scnprintf(buf + off, buf_size - off,
> > + "LMT1 -\t\t\t%#06x\n", u.v32);
> > +
> > + u.v64 = ioread64(ndev->self_mmio + AMD_BAR23LMT_OFFSET);
> > + off += scnprintf(buf + off, buf_size - off,
> > + "LMT23 -\t\t\t%#018llx\n", u.v64);
> > +
> > + u.v64 = ioread64(ndev->self_mmio + AMD_BAR45LMT_OFFSET);
> > + off += scnprintf(buf + off, buf_size - off,
> > + "LMT45 -\t\t\t%#018llx\n", u.v64);
> > +
> > + ret = simple_read_from_buffer(ubuf, count, offp, buf, off);
> > + kfree(buf);
> > + return ret;
> > +}
> > +
> > +static void ndev_init_debugfs(struct amd_ntb_dev *ndev) {
> > + if (!debugfs_dir) {
> > + ndev->debugfs_dir = NULL;
> > + ndev->debugfs_info = NULL;
> > + } else {
> > + ndev->debugfs_dir =
> > + debugfs_create_dir(ndev_name(ndev),
> debugfs_dir);
> > + if (!ndev->debugfs_dir)
> > + ndev->debugfs_info = NULL;
> > + else
> > + ndev->debugfs_info =
> > + debugfs_create_file("info", S_IRUSR,
> > + ndev->debugfs_dir, ndev,
> > + &amd_ntb_debugfs_info);
> > + }
> > +}
> > +
> > +static void ndev_deinit_debugfs(struct amd_ntb_dev *ndev) {
> > + debugfs_remove_recursive(ndev->debugfs_dir);
> > +}
> > +
> > +static inline void ndev_init_struct(struct amd_ntb_dev *ndev,
> > + struct pci_dev *pdev)
> > +{
> > + ndev->ntb.pdev = pdev;
> > + ndev->ntb.topo = NTB_TOPO_NONE;
> > + ndev->ntb.ops = &amd_ntb_ops;
> > + ndev->int_mask = AMD_EVENT_INTMASK;
> > + spin_lock_init(&ndev->db_mask_lock);
> > +}
> > +
> > +static int amd_poll_link(struct amd_ntb_dev *ndev) {
> > + void __iomem *mmio = ndev->peer_mmio;
> > + u32 reg, stat;
> > + int rc;
> > +
> > + reg = readl(mmio + AMD_SIDEINFO_OFFSET);
> > + reg &= NTB_LIN_STA_ACTIVE_BIT;
> > +
> > + dev_dbg(ndev_dev(ndev), "%s: reg_val = 0x%x.\n", __func__, reg);
> > +
> > + if (reg == ndev->cntl_sta)
> > + return 0;
> > +
> > + ndev->cntl_sta = reg;
> > +
> > + rc = pci_read_config_dword(ndev->ntb.pdev,
> > + AMD_LINK_STATUS_OFFSET, &stat);
> > + if (rc)
> > + return 0;
> > + ndev->lnk_sta = stat;
> > +
> > + return 1;
> > +}
> > +
> > +static void amd_link_hb(struct work_struct *work) {
> > + struct amd_ntb_dev *ndev = hb_ndev(work);
> > +
> > + if (amd_poll_link(ndev))
> > + ntb_link_event(&ndev->ntb);
> > +
> > + if (!amd_link_is_up(ndev))
> > + schedule_delayed_work(&ndev->hb_timer,
> AMD_LINK_HB_TIMEOUT); }
> > +
> > +static int amd_init_isr(struct amd_ntb_dev *ndev) {
> > + return ndev_init_isr(ndev, AMD_DB_CNT,
> AMD_MSIX_VECTOR_CNT); }
> > +
> > +static void amd_init_side_info(struct amd_ntb_dev *ndev) {
> > + void __iomem *mmio = ndev->self_mmio;
> > + unsigned int reg = 0;
>
> variable initialized unnecessarily

Ok.

> > +
> > + reg = readl(mmio + AMD_SIDEINFO_OFFSET);
> > + if (!(reg & 0x2)) {
> > + reg |= 0x2;
>
> I'd like a #define for the "2" above, as you are using it multiple times.

Ok.

>
> > + writel(reg, mmio + AMD_SIDEINFO_OFFSET);
> > + }
> > +}
> > +
> > +static void amd_deinit_side_info(struct amd_ntb_dev *ndev) {
> > + void __iomem *mmio = ndev->self_mmio;
> > + unsigned int reg = 0;
>
> variable initialized unnecessarily

Ok.

> > +
> > + reg = readl(mmio + AMD_SIDEINFO_OFFSET);
> > + if (reg & 0x2) {
> > + reg &= ~(0x2);
> > + writel(reg, mmio + AMD_SIDEINFO_OFFSET);
> > + readl(mmio + AMD_SIDEINFO_OFFSET);
> > + }
> > +}
> > +
> > +static int amd_init_ntb(struct amd_ntb_dev *ndev) {
> > + void __iomem *mmio = ndev->self_mmio;
> > +
> > + ndev->mw_count = AMD_MW_CNT;
> > + ndev->spad_count = AMD_SPADS_CNT;
> > + ndev->db_count = AMD_DB_CNT;
> > +
> > + switch (ndev->ntb.topo) {
> > + case NTB_TOPO_PRI:
> > + case NTB_TOPO_SEC:
> > + ndev->spad_count >>= 1;
> > + if (ndev->ntb.topo == NTB_TOPO_PRI) {
> > + ndev->self_spad = 0;
> > + ndev->peer_spad = 0x20;
> > + } else {
> > + ndev->self_spad = 0x20;
> > + ndev->peer_spad = 0;
> > + }
> > +
> > + INIT_DELAYED_WORK(&ndev->hb_timer, amd_link_hb);
> > + schedule_delayed_work(&ndev->hb_timer,
> AMD_LINK_HB_TIMEOUT);
> > +
> > + break;
> > + default:
> > + dev_err(ndev_dev(ndev), "AMD NTB does not support B2B
> mode.\n");
> > + return -EINVAL;
> > + }
> > +
> > + ndev->db_valid_mask = BIT_ULL(ndev->db_count) - 1;
> > +
> > + /* Mask event interrupts */
> > + writel(ndev->int_mask, mmio + AMD_INTMASK_OFFSET);
> > +
> > + return 0;
> > +}
> > +
> > +static inline enum ntb_topo amd_get_topo(struct amd_ntb_dev *ndev)
>
> It is usually better to let the compiler determine what to inline and what not
> to inline..

Do you mean removing the key word of inline?

> > +{
> > + void __iomem *mmio = ndev->self_mmio;
> > + u32 info;
> > +
> > + info = readl(mmio + AMD_SIDEINFO_OFFSET);
> > + if (info & AMD_SIDE_MASK)
> > + return NTB_TOPO_SEC;
> > + else
> > + return NTB_TOPO_PRI;
> > +}
> > +
> > +static int amd_init_dev(struct amd_ntb_dev *ndev) {
> > + struct pci_dev *pdev;
> > + int rc = 0;
> > +
> > + pdev = ndev_pdev(ndev);
> > +
> > + ndev->ntb.topo = amd_get_topo(ndev);
> > + dev_dbg(ndev_dev(ndev), "AMD NTB topo is %s\n",
> > + ntb_topo_string(ndev->ntb.topo));
> > +
> > + rc = amd_init_ntb(ndev);
> > + if (rc)
> > + return rc;
> > +
> > + rc = amd_init_isr(ndev);
> > + if (rc) {
> > + dev_err(ndev_dev(ndev), "fail to init isr.\n");
> > + return rc;
> > + }
> > +
> > + ndev->db_valid_mask = BIT_ULL(ndev->db_count) - 1;
> > +
> > + return 0;
> > +}
> > +
> > +static void amd_deinit_dev(struct amd_ntb_dev *ndev) {
> > + cancel_delayed_work_sync(&ndev->hb_timer);
> > +
> > + ndev_deinit_isr(ndev);
> > +}
> > +
> > +static int amd_ntb_init_pci(struct amd_ntb_dev *ndev,
> > + struct pci_dev *pdev)
> > +{
> > + int rc;
> > +
> > + pci_set_drvdata(pdev, ndev);
> > +
> > + rc = pci_enable_device(pdev);
> > + if (rc)
> > + goto err_pci_enable;
> > +
> > + rc = pci_request_regions(pdev, NTB_NAME);
> > + if (rc)
> > + goto err_pci_regions;
> > +
> > + pci_set_master(pdev);
> > +
> > + rc = pci_set_dma_mask(pdev, DMA_BIT_MASK(64));
> > + if (rc) {
> > + rc = pci_set_dma_mask(pdev, DMA_BIT_MASK(32));
> > + if (rc)
> > + goto err_dma_mask;
> > + dev_warn(ndev_dev(ndev), "Cannot DMA highmem\n");
> > + }
> > +
> > + rc = pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(64));
> > + if (rc) {
> > + rc = pci_set_consistent_dma_mask(pdev,
> DMA_BIT_MASK(32));
> > + if (rc)
> > + goto err_dma_mask;
> > + dev_warn(ndev_dev(ndev), "Cannot DMA consistent
> highmem\n");
> > + }
> > +
> > + ndev->self_mmio = pci_iomap(pdev, 0, 0);
> > + if (!ndev->self_mmio) {
> > + rc = -EIO;
> > + goto err_mmio;
> > + }
> > + ndev->peer_mmio = ndev->self_mmio + AMD_PEER_OFFSET;
> > +
> > + return 0;
> > +
> > +err_mmio:
>
> seems like an unnecessary goto destination here

Will entry the goto destination if pci_iomap failed. The code is following
Intel NTB and I see many drivers in kernel will check the return value
of pci_iomap.

>
> > +err_dma_mask:
> > + pci_clear_master(pdev);
> > +err_pci_regions:
> > + pci_disable_device(pdev);
> > +err_pci_enable:
> > + pci_set_drvdata(pdev, NULL);
> > + return rc;
> > +}
> > +
> > +static void amd_ntb_deinit_pci(struct amd_ntb_dev *ndev) {
> > + struct pci_dev *pdev = ndev_pdev(ndev);
> > +
> > + pci_iounmap(pdev, ndev->self_mmio);
> > +
> > + pci_clear_master(pdev);
> > + pci_release_regions(pdev);
> > + pci_disable_device(pdev);
> > + pci_set_drvdata(pdev, NULL);
> > +}
> > +
> > +
> > +static int amd_ntb_pci_probe(struct pci_dev *pdev,
> > + const struct pci_device_id *id) {
> > + struct amd_ntb_dev *ndev;
> > + int rc, node;
> > +
> > + node = dev_to_node(&pdev->dev);
> > +
> > + ndev = kzalloc_node(sizeof(*ndev), GFP_KERNEL, node);
> > + if (!ndev) {
> > + rc = -ENOMEM;
> > + goto err_ndev;
> > + }
> > +
> > + ndev_init_struct(ndev, pdev);
> > +
> > + rc = amd_ntb_init_pci(ndev, pdev);
> > + if (rc)
> > + goto err_init_pci;
> > +
> > + rc = amd_init_dev(ndev);
> > + if (rc)
> > + goto err_init_dev;
> > +
> > + /* write side info */
> > + amd_init_side_info(ndev);
> > +
> > + amd_poll_link(ndev);
> > +
> > + ndev_init_debugfs(ndev);
> > +
> > + rc = ntb_register_device(&ndev->ntb);
> > + if (rc)
> > + goto err_register;
> > +
> > + dev_info(&pdev->dev, "NTB device registered.\n");
> > +
> > + return 0;
> > +
> > +err_register:
> > + ndev_deinit_debugfs(ndev);
> > + amd_deinit_dev(ndev);
> > +err_init_dev:
> > + amd_ntb_deinit_pci(ndev);
> > +err_init_pci:
> > + kfree(ndev);
> > +err_ndev:
> > + return rc;
> > +}
> > +
> > +static void amd_ntb_pci_remove(struct pci_dev *pdev) {
> > + struct amd_ntb_dev *ndev = pci_get_drvdata(pdev);
> > +
> > + ntb_unregister_device(&ndev->ntb);
> > + ndev_deinit_debugfs(ndev);
> > + amd_deinit_side_info(ndev);
> > + amd_deinit_dev(ndev);
> > + amd_ntb_deinit_pci(ndev);
> > + kfree(ndev);
> > +}
> > +
> > +static const struct file_operations amd_ntb_debugfs_info = {
> > + .owner = THIS_MODULE,
> > + .open = simple_open,
> > + .read = ndev_debugfs_read,
> > +};
> > +
> > +static const struct pci_device_id amd_ntb_pci_tbl[] = {
> > + {PCI_VDEVICE(AMD, PCI_DEVICE_ID_AMD_NTB)},
> > + {0}
> > +};
> > +MODULE_DEVICE_TABLE(pci, amd_ntb_pci_tbl);
> > +
> > +static struct pci_driver amd_ntb_pci_driver = {
> > + .name = KBUILD_MODNAME,
> > + .id_table = amd_ntb_pci_tbl,
> > + .probe = amd_ntb_pci_probe,
> > + .remove = amd_ntb_pci_remove,
> > +};
> > +
> > +static int __init amd_ntb_pci_driver_init(void) {
> > + pr_info("%s %s\n", NTB_DESC, NTB_VER);
> > +
> > + if (debugfs_initialized())
> > + debugfs_dir = debugfs_create_dir(KBUILD_MODNAME,
> NULL);
> > +
> > + return pci_register_driver(&amd_ntb_pci_driver);
> > +}
> > +module_init(amd_ntb_pci_driver_init);
> > +
> > +static void __exit amd_ntb_pci_driver_exit(void) {
> > + pci_unregister_driver(&amd_ntb_pci_driver);
> > + debugfs_remove_recursive(debugfs_dir);
> > +}
> > +module_exit(amd_ntb_pci_driver_exit);
> > diff --git a/drivers/ntb/hw/amd/ntb_hw_amd.h
> > b/drivers/ntb/hw/amd/ntb_hw_amd.h new file mode 100644 index
> > 0000000..31021c0
> > --- /dev/null
> > +++ b/drivers/ntb/hw/amd/ntb_hw_amd.h
> > @@ -0,0 +1,246 @@
> > +/*
> > + * 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@xxxxxxx>
>
> Same comment as above about the space needed here.

Ok

> > + */
> > +
> > +#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)
>
> Tab align the second half of these

I'll check it.

>
> > +#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 ioread64
> > +#ifdef readq
> > +#define ioread64 readq
> > +#else
> > +#define ioread64 _ioread64
> > +static inline u64 _ioread64(void __iomem *mmio) {
> > + u64 low, high;
> > +
> > + low = ioread32(mmio);
> > + high = ioread32(mmio + sizeof(u32));
> > + return low | (high << 32);
> > +}
> > +#endif
> > +#endif
> > +
> > +#ifndef iowrite64
> > +#ifdef writeq
> > +#define iowrite64 writeq
> > +#else
> > +#define iowrite64 _iowrite64
> > +static inline void _iowrite64(u64 val, void __iomem *mmio) {
> > + iowrite32(val, mmio);
> > + iowrite32(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),
> > +
> > + /* 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,
> > +};
>
> It seems extremely odd to mix and match different kinds of things in the
> same enumerated type. I'd prefer to have these as #defines or separated
> enum types.

The code following AHCI.h style, it put field definition of register close to register
Marco definition seems appropriate to me. Actually, I have seen lot of the style in kernel.

> > +
> > +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;
> > +
> > + 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)
> > +
>
> This should probably be moved into the device driver C file (as they are not
> called anywhere else).

I just following intel ntb driver, I'll also change it if you change intel driver.

>
> > +static int amd_ntb_mw_count(struct ntb_dev *ntb); static int
> > +amd_ntb_mw_get_range(struct ntb_dev *ntb, int idx,
> > + phys_addr_t *base, resource_size_t *size,
> > + resource_size_t *align, resource_size_t *algin_size);
> static int
> > +amd_ntb_mw_set_trans(struct ntb_dev *ndev, int idx,
> > + dma_addr_t addr, resource_size_t size);
> static int
> > +amd_ntb_link_is_up(struct ntb_dev *ntb,
> > + enum ntb_speed *speed,
> > + enum ntb_width *width);
> > +static int amd_ntb_link_enable(struct ntb_dev *ntb,
> > + enum ntb_speed speed,
> > + enum ntb_width width);
> > +static int amd_ntb_link_disable(struct ntb_dev *ntb); static u64
> > +amd_ntb_db_valid_mask(struct ntb_dev *ntb); static int
> > +amd_ntb_db_vector_count(struct ntb_dev *ntb); static u64
> > +amd_ntb_db_vector_mask(struct ntb_dev *ntb, int db_vector); static
> > +u64 amd_ntb_db_read(struct ntb_dev *ntb); static int
> > +amd_ntb_db_clear(struct ntb_dev *ntb, u64 db_bits); static int
> > +amd_ntb_db_set_mask(struct ntb_dev *ntb, u64 db_bits); static int
> > +amd_ntb_db_clear_mask(struct ntb_dev *ntb, u64 db_bits); static int
> > +amd_ntb_peer_db_addr(struct ntb_dev *ntb,
> > + phys_addr_t *db_addr,
> > + resource_size_t *db_size);
> > +static int amd_ntb_peer_db_set(struct ntb_dev *ntb, u64 db_bits);
> > +static int amd_ntb_spad_count(struct ntb_dev *ntb); static u32
> > +amd_ntb_spad_read(struct ntb_dev *ntb, int idx); static int
> > +amd_ntb_spad_write(struct ntb_dev *ntb, int idx, u32 val); static int
> > +amd_ntb_peer_spad_addr(struct ntb_dev *ntb, int idx,
> > + phys_addr_t *spad_addr);
> > +static u32 amd_ntb_peer_spad_read(struct ntb_dev *ntb, int idx);
> > +static int amd_ntb_peer_spad_write(struct ntb_dev *ntb, int idx, u32
> > +val);
>
> I believe all of these function declarations should be removed.
Ok.

And please see my comments, I'll submit v4 patch immediately when getting your feedback.