Re: [PATCH v4 08/24] fpga: add FPGA DFL PCIe device driver

[Wu Hao <hao.wu@intel.com>]

On Thu, Mar 15, 2018 at 11:49:56AM -0700, Moritz Fischer wrote:
> Hi Hao,
> 
> On Tue, Feb 13, 2018 at 05:24:37PM +0800, Wu Hao wrote:
> > From: Zhang Yi <yi.z.zhang@intel.com>
> > 
> > This patch implements the basic framework of the driver for FPGA PCIe
> > device which implements the Device Feature List (DFL) in its MMIO space.
> > This driver is verified on Intel(R) PCIe based FPGA DFL devices, including
> > both integrated (e.g Intel Server Platform with In-package FPGA) and
> > discrete (e.g Intel FPGA PCIe Acceleration Cards) solutions.
> > 
> > Signed-off-by: Tim Whisonant <tim.whisonant@intel.com>
> > Signed-off-by: Enno Luebbers <enno.luebbers@intel.com>
> > Signed-off-by: Shiva Rao <shiva.rao@intel.com>
> > Signed-off-by: Christopher Rauer <christopher.rauer@intel.com>
> > Signed-off-by: Zhang Yi <yi.z.zhang@intel.com>
> > Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
> > Signed-off-by: Wu Hao <hao.wu@intel.com>
> 
> with module_pci_driver() fix:
> 
> Acked-by: Moritz Fischer <mdf@kernel.org>
> > ---
> > v2: move the code to drivers/fpga folder as suggested by Alan Tull.
> >     switch to GPLv2 license.
> >     fix comments from Moritz Fischer.
> > v3: switch to pci_set_dma_mask/consistent_dma_mask() function.
> >     remove pci_save_state() in probe function.
> >     rename driver to INTEL_FPGA_DFL_PCI and intel-dfl-pci.c to indicate
> >     this driver supports Intel FPGA PCI devices which implement DFL.
> >     improve Kconfig description for INTEL_FPGA_DFL_PCI
> > v4: rename to FPGA_DFL_PCI (dfl-pci.c) for better reuse.
> >     fix SPDX license issue.
> > ---
> >  drivers/fpga/Kconfig   |  15 ++++++
> >  drivers/fpga/Makefile  |   3 ++
> >  drivers/fpga/dfl-pci.c | 127 +++++++++++++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 145 insertions(+)
> >  create mode 100644 drivers/fpga/dfl-pci.c
> > 
> > diff --git a/drivers/fpga/Kconfig b/drivers/fpga/Kconfig
> > index 01ad31f..87f3d44 100644
> > --- a/drivers/fpga/Kconfig
> > +++ b/drivers/fpga/Kconfig
> > @@ -140,4 +140,19 @@ config FPGA_DFL
> >  	  Gate Array (FPGA) solutions which implement Device Feature List.
> >  	  It provides enumeration APIs, and feature device infrastructure.
> >  
> > +config FPGA_DFL_PCI
> > +	tristate "FPGA Device Feature List (DFL) PCIe Device Driver"
> > +	depends on PCI && FPGA_DFL
> > +	help
> > +	  Select this option to enable PCIe driver for PCIe based
> > +	  Field-Programmable Gate Array (FPGA) solutions which implemented
> > +	  the Device Feature List (DFL). This driver provides interfaces
> > +	  for userspace applications to configure, enumerate, open and access
> > +	  FPGA accelerators on the FPGA DFL devices, enables system level
> > +	  management functions such as FPGA partial reconfiguration, power
> > +	  management, and virtualization with DFL framework and DFL feature
> > +	  device drivers.
> > +
> > +	  To compile this as a module, choose M here.
> > +
> >  endif # FPGA
> > diff --git a/drivers/fpga/Makefile b/drivers/fpga/Makefile
> > index c4c62b9..4375630 100644
> > --- a/drivers/fpga/Makefile
> > +++ b/drivers/fpga/Makefile
> > @@ -30,3 +30,6 @@ obj-$(CONFIG_OF_FPGA_REGION)		+= of-fpga-region.o
> >  
> >  # FPGA Device Feature List Support
> >  obj-$(CONFIG_FPGA_DFL)			+= dfl.o
> > +
> > +# Drivers for FPGAs which implement DFL
> > +obj-$(CONFIG_FPGA_DFL_PCI)		+= dfl-pci.o
> > diff --git a/drivers/fpga/dfl-pci.c b/drivers/fpga/dfl-pci.c
> > new file mode 100644
> > index 0000000..d91ea42
> > --- /dev/null
> > +++ b/drivers/fpga/dfl-pci.c
> > @@ -0,0 +1,127 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Driver for FPGA Device Feature List (DFL) PCIe device
> > + *
> > + * Copyright (C) 2017 Intel Corporation, Inc.
> > + *
> > + * Authors:
> > + *   Zhang Yi <Yi.Z.Zhang@intel.com>
> > + *   Xiao Guangrong <guangrong.xiao@linux.intel.com>
> > + *   Joseph Grecco <joe.grecco@intel.com>
> > + *   Enno Luebbers <enno.luebbers@intel.com>
> > + *   Tim Whisonant <tim.whisonant@intel.com>
> > + *   Ananda Ravuri <ananda.ravuri@intel.com>
> > + *   Henry Mitchel <henry.mitchel@intel.com>
> > + */
> > +
> > +#include <linux/pci.h>
> > +#include <linux/types.h>
> > +#include <linux/kernel.h>
> > +#include <linux/module.h>
> > +#include <linux/stddef.h>
> > +#include <linux/errno.h>
> > +#include <linux/aer.h>
> > +
> > +#define DRV_VERSION	"0.8"
> > +#define DRV_NAME	"dfl-pci"
> > +
> > +/* PCI Device ID */
> > +#define PCIE_DEVICE_ID_PF_INT_5_X	0xBCBD
> > +#define PCIE_DEVICE_ID_PF_INT_6_X	0xBCC0
> > +#define PCIE_DEVICE_ID_PF_DSC_1_X	0x09C4
> > +/* VF Device */
> > +#define PCIE_DEVICE_ID_VF_INT_5_X	0xBCBF
> > +#define PCIE_DEVICE_ID_VF_INT_6_X	0xBCC1
> > +#define PCIE_DEVICE_ID_VF_DSC_1_X	0x09C5
> > +
> > +static struct pci_device_id cci_pcie_id_tbl[] = {
> > +	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCIE_DEVICE_ID_PF_INT_5_X),},
> > +	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCIE_DEVICE_ID_VF_INT_5_X),},
> > +	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCIE_DEVICE_ID_PF_INT_6_X),},
> > +	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCIE_DEVICE_ID_VF_INT_6_X),},
> > +	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCIE_DEVICE_ID_PF_DSC_1_X),},
> > +	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCIE_DEVICE_ID_VF_DSC_1_X),},
> > +	{0,}
> > +};
> > +MODULE_DEVICE_TABLE(pci, cci_pcie_id_tbl);
> > +
> > +static
> > +int cci_pci_probe(struct pci_dev *pcidev, const struct pci_device_id *pcidevid)
> > +{
> > +	int ret;
> > +
> > +	ret = pci_enable_device(pcidev);
> > +	if (ret < 0) {
> > +		dev_err(&pcidev->dev, "Failed to enable device %d.\n", ret);
> > +		return ret;
> > +	}
> > +
> > +	ret = pci_enable_pcie_error_reporting(pcidev);
> > +	if (ret && ret != -EINVAL)
> > +		dev_info(&pcidev->dev, "PCIE AER unavailable %d.\n", ret);
> > +
> > +	ret = pci_request_regions(pcidev, DRV_NAME);
> > +	if (ret) {
> > +		dev_err(&pcidev->dev, "Failed to request regions.\n");
> > +		goto disable_error_report_exit;
> > +	}
> > +
> > +	pci_set_master(pcidev);
> > +
> > +	if (!pci_set_dma_mask(pcidev, DMA_BIT_MASK(64))) {
> > +		ret = pci_set_consistent_dma_mask(pcidev, DMA_BIT_MASK(64));
> > +		if (ret)
> > +			goto release_region_exit;
> > +	} else if (!pci_set_dma_mask(pcidev, DMA_BIT_MASK(32))) {
> > +		ret = pci_set_consistent_dma_mask(pcidev, DMA_BIT_MASK(32));
> > +		if (ret)
> > +			goto release_region_exit;
> > +	} else {
> > +		ret = -EIO;
> > +		dev_err(&pcidev->dev, "No suitable DMA support available.\n");
> > +		goto release_region_exit;
> > +	}
> > +
> > +	/* TODO: create and add the platform device per feature list */
> > +	return 0;
> > +
> > +release_region_exit:
> > +	pci_release_regions(pcidev);
> > +disable_error_report_exit:
> > +	pci_disable_pcie_error_reporting(pcidev);
> > +	pci_disable_device(pcidev);
> > +	return ret;
> > +}
> > +
> > +static void cci_pci_remove(struct pci_dev *pcidev)
> > +{
> > +	pci_release_regions(pcidev);
> > +	pci_disable_pcie_error_reporting(pcidev);
> > +	pci_disable_device(pcidev);
> > +}
> > +
> > +static struct pci_driver cci_pci_driver = {
> > +	.name = DRV_NAME,
> > +	.id_table = cci_pcie_id_tbl,
> > +	.probe = cci_pci_probe,
> > +	.remove = cci_pci_remove,
> > +};
> > +
> > +static int __init ccidrv_init(void)
> > +{
> > +	pr_info("FPGA DFL PCIe Driver: Version %s\n", DRV_VERSION);
> 
> Not a fan of the additional output. Can you make it module_pci_driver?

Hi Moritz,

Thanks a lot for the review and comments.

I will use module_pci_driver and MODULE_VERSION(DRV_VERSION)
instead of the additional output in the next version. :)

Thanks
Hao

> > +
> > +	return pci_register_driver(&cci_pci_driver);
> > +}
> > +
> > +static void __exit ccidrv_exit(void)
> > +{
> > +	pci_unregister_driver(&cci_pci_driver);
> > +}
> > +
> > +module_init(ccidrv_init);
> > +module_exit(ccidrv_exit);
> > +
> > +MODULE_DESCRIPTION("FPGA DFL PCIe Device Driver");
> > +MODULE_AUTHOR("Intel Corporation");
> > +MODULE_LICENSE("GPL v2");
> > -- 
> > 2.7.4
> >