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

From: Wu Hao
Date: Fri Mar 16 2018 - 00:39:31 EST


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@xxxxxxxxx>
> >
> > 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@xxxxxxxxx>
> > Signed-off-by: Enno Luebbers <enno.luebbers@xxxxxxxxx>
> > Signed-off-by: Shiva Rao <shiva.rao@xxxxxxxxx>
> > Signed-off-by: Christopher Rauer <christopher.rauer@xxxxxxxxx>
> > Signed-off-by: Zhang Yi <yi.z.zhang@xxxxxxxxx>
> > Signed-off-by: Xiao Guangrong <guangrong.xiao@xxxxxxxxxxxxxxx>
> > Signed-off-by: Wu Hao <hao.wu@xxxxxxxxx>
>
> with module_pci_driver() fix:
>
> Acked-by: Moritz Fischer <mdf@xxxxxxxxxx>
> > ---
> > 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@xxxxxxxxx>
> > + * Xiao Guangrong <guangrong.xiao@xxxxxxxxxxxxxxx>
> > + * Joseph Grecco <joe.grecco@xxxxxxxxx>
> > + * Enno Luebbers <enno.luebbers@xxxxxxxxx>
> > + * Tim Whisonant <tim.whisonant@xxxxxxxxx>
> > + * Ananda Ravuri <ananda.ravuri@xxxxxxxxx>
> > + * Henry Mitchel <henry.mitchel@xxxxxxxxx>
> > + */
> > +
> > +#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
> >