Open Programmable Accelerator Engine (OPAE) Linux Device Driver Architecture

The OPAE Intel® FPGA Linux Device Driver provides interfaces for userspace applications to configure, enumerate, open, and access FPGA accelerators on platforms equipped with Intel FPGA solutions. The OPAE FPGA driver also enables system-level management functions such as FPGA reconfiguration and virtualization.

Hardware Architecture

The Linux Operating System treats the FPGA hardware as a PCIe* device. A predefined data structure Device Feature List (DFL) defines PCIe memory.

FPGA

The Linux Device Driver uses PCIe Single Root I/O Virtualization (SR-IOV) to create Virtual Functions (VFs). The device driver can assign individual accelerators to virtual machines (VMs).

Virtualized

FPGA Management Engine (FME)

The FPGA Management Engine provides error reporting, reconfiguration, performance reporting, and other infrastructure functions. Each FPGA has one FME which is always accessed through the Physical Function (PF). The Intel Xeon® Processor with Integrated FPGA also performs power and thermal management. These functions are not available on the Intel Programmable Acceleration Card (PAC).

User-space applications can acquire exclusive access to the FME using open(), and release it using close() as a privileged user (root).

If an application terminates without freeing the FME or Port resources, Linux closes all
file descriptors owned by the terminating process, freeing those resources.

Port

A Port represents the interface between two components: * The FPGA Interface Manager (FIM) which is the static FPGA fabric * The Accelerator Function (AF) which is the partially reconfigurable region

The Port controls the communication from software to the AF and makes features such as reset and debug available. A PCIe device may have several Ports. Assign multiple ports to VFs using the FPGA_FME_PORT_ASSIGN ioctl on the FME device.

Accelerator Function (AF)

An AF attaches to a Port. The AF provides a 256 KB memory mapped I/O (MMIO) region for accelerator-specific control registers.

  • Use open() on the Port device to acquire exclusive access to an AFU associated with the Port device.
  • Use close()on the Port device to release the AFU associated with the Port device.
  • Use mmap() on the Port device to map accelerator MMIO regions.

Partial Reconfiguration (PR)

Use PR to reconfigure an AF file. Successful reconfiguration has two requirements:

  • You must generate the reconfiguration AF for the exact FIM. The AF and FIM are compatible if their IDs match. You can verify this match by comparing the interface ID in the AF header against the interface ID the available through sysfs intel-fpga-dev.*i*/intel-fpga-fme.*j*/pr/interface_ID. PR always performs this check before reconfiguring the AF.
  • The AF must also target the reconfigurable region (Port) of the FPGA.

In all other cases PR fails and may cause system instability.

Platforms that support 512-bit Partial Reconfiguration require
binutils >= version 2.25.

Close any software program accessing the FPGA, including software programs running in a virtualized host before initiating PR. Here is the recommended sequence:

  1. Unload the driver from the guest
  2. Unplug the VF from the guest
NOTE: Unplugging the VF from the guest while an application on the guest is
still accessing its resources may lead to VM instabilities. We recommend
closing all applications accessing the VF in the guest before unplugging the
VF.
  1. Disable SR-IOV
  2. Perform PR
  3. Enable SR-IOV
  4. Plug the VF to the guest
  5. Load the driver in the guest

FPGA Virtualization

To enable accelerator access from applications running on a VM, assign the AF Port to a VF using the following process:

  1. Release the Port from the PF using the FPGA_FME_PORT_RELEASE ioctl on the FME device.
  2. Use the following command to enable SR-IOV and VFs. Each VF can own a single Port with an AF. In the following command, N is the number of Port released from the PF.
echo N > $PCI_DEVICE_PATH/sriov_numvfs
  1. Pass through the VFs to VMs.
  2. You access the AF on a VF from applications running on the VM using the same driver inside the VF.
You cannot assign an FME to a VF. Consequently, PR and other management functions are only available through
the PFs.

Driver Organization

PCIe Module Device Driver

!## Driver Organization ##

PCIe Module Device Driver

Driver

FPGA devices appear as a PCIe devices. Once enumeration detects a PCIe PF or VF, the Linux OS loads the FPGA PCIe device driver, intel-fpga-pci.ko. The device driver performs the following functions:

  1. Creates an FPGA container device as parent of the feature devices.
  2. Walks through the Device Feature List in PCIe device base address register (BAR) memory to discover feature devices and their sub-features. Creates platform devices for the features and sub-features under the container device.
  3. Supports SR-IOV.
  4. Introduces the feature device infrastructure, which abstracts operations for sub-features and provides common functions to feature device drivers.

PCIe Module Device Driver Functions

The PCIe Module Device Driver performs the following functions:

  1. PCIe discovery, device enumeration, and feature discovery.
  2. Creates sysfs directories for the parent device, FME, and Port.
  3. Creates the platform driver instances, causing the Linux kernel to load their respective platform module drivers.

FME Platform Module Device Driver

The FME Platform Module Device Driver, intel-fpga-fme.ko, loads automatically after the PCIe driver creates the FME Platform Module. It provides the following features for FPGA management:

  1. Power and thermal management, error reporting, performance reporting, and other infrastructure functions. You can access these functions via sysfs interfaces the FME driver provides.
The Power and thermal management function are only available on the Intel Xeon Processor with Integrated FPGA.
  1. Partial Reconfiguration. During PR sub-feature initialization, the FME driver registers the FPGA Manager framework to support PR. When the FME receives an FPGA_FME_PORT_PR ioctl from user-space, it invokes the common interface function from the FPGA Manager to reconfigure the AF using PR.
  2. Port management for virtualization. The FME driver introduces two ioctls:
  • FPGA_FME_PORT_RELEASE releases a Port from the PF
  • FPGA_FME_PORT_ASSIGN assigns a Port back to PF

After FPGA_FME_PORT_RELEASE completes, you can use the PCIe driver SR-IOV interfaces to reassign the Port to a VF.

For more information, refer to “FPGA Virtualization”.

FME Platform Module Device Driver Functions

The FME Platform Module Device Driver performs the the following functions:

  • Creates the FME character device node.
  • Creates the FME sysfs files and implements the FME sysfs file accessors.
  • Implements the FME private feature sub-drivers.
  • FME private feature sub-drivers: * FME Header * Thermal Management - available only on the Intel Xeon Processor with Integrated FPGA * Power Management - available only on the Intel Xeon Processor with Integrated FPGA * Global Error * Partial Reconfiguration * Global Performance

Port Platform Module Device Driver

After the PCIe Module Device Driver creates the Port Platform Module device, the FPGA Port and AF driver, intel-fpga-afu.ko, are available. This module provides an interface for user-space applications to access the individual accelerators, including basic reset control on the Port, AF MMIO region export, DMA buffer mapping service, UMsg notification, and remote debug functions. UMsg is only supported on the Intel Xeon Processor with Integrated FPGA.

Port Platform Module Device Driver Functions

The Port Platform Module Device Driver performs the the following functions:

  • Creates the Port character device node.
  • Creates the Port sysfs files and implements the Port sysfs file accessors.
  • Implements the following Port private feature sub-drivers. * Port Header * AFU * Port Error * UMsg - UMsg is only supported through the Intel Xeon Processor with Integrated FPGA. * Signal Tap

Platform Specific Device Drivers

These drivers enable platform specific features.

Device Driver Function Intel PAC with Arria 10 GX Intel PAC D5005 Intel FPGA PAC N3000
i2c-altera I2C Master driver to retrieve MAC address from MAC PROM. No Yes No
intel-gener ic-qspi QSPI master driver used to access flash. This driver is not used when Intel PAC has been upgraded to enable Root of Trust. Yes Yes No
intel-on-ch ip-flash Supports read/write access to flash and on-chip MAX10 Flash using the mtd device. Yes Yes No
altera-asmi p2 Altera ASMI Parallel II Intel® driver to support flash read and write. No No Yes
spi-altera- mod SPI master driver. It enables communication with MAX10. Yes Yes No
spi-nor-mod SPI-nor driver to support flash. Used during the non-RoT to RoT (Root of trust) update process. Yes Yes Yes
intel-max10 Driver to support FPGA flash, BMC and retrieval of sensor information Yes Yes No
avmmi-bmc Avalon Memory Mapped Interface to BMC driver to support retrieval of sensor information No No Yes
intel-fpga- pac-hssi Driver for HSSI Configurable Ethernet support Yes No Yes
intel-fpga- pac-iopll Driver for the IOPLL. Allows user code to read and set optimal clock frequency to drive logic for a given AFU. Yes No No
pac_n3000_net Network device driver for Intel® PAC N3000. This allows to retrieve link status and link statistics by creating network interface for PHY/MAC pairs on the line side. No Yes No
c827_retim er C827 Retimer driver. It retrieves retimer link status and register with pac_n3000_net driver. No Yes No
ifpga-sec-m gr Security manager class driver. This driver enables read write routines for secure updates. Required by fpgasupdate tool. Yes Yes Yes

Application FPGA Device Enumeration

Applications enumerate the FPGA device from the sysfs hierarchy under /sys/class/fpga.

In the example below the host includes two Intel FPGA devices. Each FPGA device has one FME and two Ports (AFUs).

Each FPGA device has a device directory under /sys/class/fpga:

/sys/class/fpga/intel-fpga-dev.0
/sys/class/fpga/intel-fpga-dev.1

Each node has one FME and two Ports (AFUs) as child devices:

/sys/class/fpga/intel-fpga-dev.0/intel-fpga-fme.0
/sys/class/fpga/intel-fpga-dev.0/intel-fpga-port.0
/sys/class/fpga/intel-fpga-dev.0/intel-fpga-port.1

/sys/class/fpga/intel-fpga-dev.1/intel-fpga-fme.1
/sys/class/fpga/intel-fpga-dev.1/intel-fpga-port.2
/sys/class/fpga/intel-fpga-dev.1/intel-fpga-port.3

In general, the FME/Port sysfs interfaces use the following naming convention:

/sys/class/fpga/intel-fpga-dev.i/intel-fpga-fme.j/
/sys/class/fpga/intel-fpga-dev.i/intel-fpga-port.k/
  • i consecutively numbers all of the container devices
  • j consecutively numbers the FMEs
  • k consecutively numbers all Ports

Use the following device nodes to make ioctl() and mmap() calls:

/dev/intel-fpga-fme.j
/dev/intel-fpga-port.k

PCIe Driver Enumeration

intel-fpga-pci.ko performs device enumeration. This section highlights the main data structures and functions of intel-fpga-pci.ko. For more detailed information refer to the source code, pcie.c.

Enumeration Data Structures

enum fpga_id_type {
    PARENT_ID,
    FME_ID,
    PORT_ID,
    FPGA_ID_MAX
};

static struct idr fpga_ids[FPGA_ID_MAX];

struct fpga_chardev_info {
    const char *name;
    dev_t devt;
};

struct fpga_chardev_info fpga_chrdevs[] = {
    { .name = FPGA_FEATURE_DEV_FME },
    { .name = FPGA_FEATURE_DEV_PORT },
};

static struct class *fpga_class;

  static struct pci_device_id cci_pcie_id_tbl[] = {
    {PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCIe_DEVICE_ID_RCiEP0_MCP),},
{PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCIe_DEVICE_ID_VF_MCP),},
      {PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCIe_DEVICE_ID_RCiEP0_SKX_P),},
      {PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCIe_DEVICE_ID_VF_SKX_P),},
      {PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCIe_DEVICE_ID_RCiEP0_DCP),},
      {PCI_DEVICE(PCI_VENDOR_ID_INTEL, PCIe_DEVICE_ID_VF_DCP),},
      {0,}
  };

  static struct pci_driver cci_pci_driver = {
      .name = DRV_NAME,
      .id_table = cci_pcie_id_tbl,
      .probe = cci_pci_probe,
      .remove = cci_pci_remove,
      .sriov_configure = cci_pci_sriov_configure
  };

struct cci_drvdata {
    int device_id;
    struct device *fme_dev;
    struct mutex lock;
    struct list_head port_dev_list;
    int released_port_num;
    struct list_head regions;
};

struct build_feature_devs_info {
    struct pci_dev *pdev;
    void __iomem *ioaddr;
    void __iomem *ioend;
    int current_bar;
    void __iomem *pfme_hdr;
    struct device *parent_dev;
    struct platform_device *feature_dev;
};

Enumeration Flow

  • ccidrv_init() * Initialize fpga_ids using idr_init(). * Initialize fpga_chrdevs[i].devt using alloc_chrdev_region(). * Initialize fpga_class using class_create(). * pci_register_driver(&cci_pci_driver);
  • cci_pci_probe() * Enable the PCI device, request access to its regions, set PCI master mode, configure DMA.
  • cci_pci_create_feature_devs() build_info_alloc_and_init() * Allocate a struct build_feature_devs_info, initialize it.. * .parent_dev is set to a parent sysfs directory (intel-fpga-dev.*id*) that contains the FME and Port sysfs directories.
  • parse_feature_list() * Walk the BAR0 Device Feature List to discover the FME, the Port, and their private features.
  • parse_feature() parse_feature_afus() parse_feature_fme() * When enumeration discovers an FME: * build_info_create_dev() * Allocate a platform device for the FME, storing in build_feature_devs_info.feature_dev. * feature_dev.id is initialized to the result of idr_alloc(fpga_ids[FME_ID], * feature_dev.parent is set to build_feature_devs_info.parent_dev. * Allocate an array of struct resource in feature_dev.resource. * Allocate a struct feature_platform_data, initialize it, and store a pointer in feature_dev.dev.platform_data * create_feature_instance() build_info_add_sub_feature() * Initialize feature_dev.resource[FME_FEATURE_ID_HEADER]. * feature_platform_data_add() * Initialize feature_platform_data.features[FME_FEATURE_ID_HEADER], everything but .fops.
  • parse_feature() parse_feature_afus() parse_feature_port() * When enumeration discovers a Port: * build_info_create_dev() * Allocate a platform device for the Port, storing in build_feature_devs_info.feature_dev. * feature_dev.id is initialized to the result of idr_alloc(fpga_ids[PORT_ID], * feature_dev.parent is set to build_feature_devs_info.parent_dev. * Allocate an array of struct resource in feature_dev.resource. * Allocate a struct feature_platform_data, initialize it, and store a pointer in feature_dev.dev.platform_data * build_info_commit_dev() * Add the struct feature_platform_data.node for the Port to the list of Ports in struct cci_drvdata.port_dev_list * create_feature_instance() build_info_add_sub_feature() * Initialize feature_dev.resource[PORT_FEATURE_ID_HEADER]. * feature_platform_data_add() * Initialize feature_platform_data.features[PORT_FEATURE_ID_HEADER], everything but .fops.
  • parse_feature() parse_feature_afus() parse_feature_port_uafu() * When enumeration discovers an AFU: * create_feature_instance() build_info_add_sub_feature() * Initialize feature_dev.resource[PORT_FEATURE_ID_UAFU]. * feature_platform_data_add() * Initialize feature_platform_data.features[PORT_FEATURE_ID_UAFU], everything but .fops.
  • parse_feature() parse_feature_private() parse_feature_fme_private() * When enumeration discovers an FME private feature: * create_feature_instance() build_info_add_sub_feature() * Initialize feature_dev.resource[id]. * feature_platform_data_add() * Initialize feature_platform_data.features[id], everything but .fops.
  • parse_feature() parse_feature_private() parse_feature_port_private()
    • When a Port private feature is encountered: * create_feature_instance() build_info_add_sub_feature() * Initialize feature_dev.resource[id]. * feature_platform_data_add() * Initialize feature_platform_data.features[id], everything but .fops.
  • parse_ports_from_fme() * If the driver is loaded on the Physical Function (PF), then.. * Run the parse_feature_list() flow on each port described in the FME header. * Use the BAR mentioned in each Port entry in the header.

FME Platform Device Initialization

intel-fpga-fme.ko performs FME device initialization. This section highlights the main data structures and and functions. For more information refer to the source code, fme-main.c.

FME Platform Device Data Structures

struct feature_ops {
    int (*init)(struct platform_device *pdev, struct feature *feature);
    int (*uinit)(struct platform_device *pdev, struct feature *feature);
    long (*ioctl)(struct platform_device *pdev, struct feature *feature,
                unsigned int cmd, unsigned long arg);
    int (*test)(struct platform_device *pdev, struct feature *feature);
};

struct feature {
    const char *name;
    int resource_index;
    void __iomem *ioaddr;
    struct feature_ops *ops;
};

struct feature_platform_data {
    struct list_head node;
    struct mutex lock;
    unsigned long dev_status;
    struct cdev cdev;
    struct platform_device *dev;
    unsigned int disable_count;
    void *private;
    int num;
    int (*config_port)(struct platform_device *, u32, bool);
    struct platform_device *(*fpga_for_each_port)(struct platform_device *,
            void *, int (*match)(struct platform_device *, void *));
    struct feature features[0];
};

struct perf_object {
    int id;
    const struct attribute_group **attr_groups;
    struct device *fme_dev;
    struct list_head node;
    struct list_head children;
    struct kobject kobj;
};

struct fpga_fme {
    u8 port_id;
    u64 pr_err;
    struct device *dev_err;
    struct perf_object *perf_dev;
    struct feature_platform_data *pdata;
};

FME Platform Device Initialization Flow

FME
  • fme_probe() fme_dev_init() * Initialize a struct fpga_fme and store it in the feature_platform_data.private field.
  • fme_probe() fpga_dev_feature_init() feature_instance_init() * Save a struct feature_ops into the feature_platform_data.features for each populated feature. * Call the test function, if any, from the struct. * Call the init function from the struct.
  • fme_probe() fpga_register_dev_ops() * Create the FME character device node, registering a struct file_operations.

Port Platform Device Initialization

intel-fpga-afu.ko performs Port device initialization. This section highlights the main data structures and and functions. For more detailed information refer to the source code, afu.c.

Port Platform Device Data Structures

struct feature_ops {
    int (*init)(struct platform_device *pdev, struct feature *feature);
    int (*uinit)(struct platform_device *pdev, struct feature *feature);
    long (*ioctl)(struct platform_device *pdev, struct feature *feature,
                unsigned int cmd, unsigned long arg);
    int (*test)(struct platform_device *pdev, struct feature *feature);
};

struct feature {
    const char *name;
    int resource_index;
    void __iomem *ioaddr;
    struct feature_ops *ops;
};

struct feature_platform_data {
    struct list_head node;
    struct mutex lock;
    unsigned long dev_status;
    struct cdev cdev;
    struct platform_device *dev;
    unsigned int disable_count;
    void *private;
    int num;
    int (*config_port)(struct platform_device *, u32, bool);
    struct platform_device *(*fpga_for_each_port)(struct platform_device *,
            void *, int (*match)(struct platform_device *, void *));
    struct feature features[0];
};

struct fpga_afu_region {
    u32 index;
    u32 flags;
    u64 size;
    u64 offset;
    u64 phys;
    struct list_head node;
};

struct fpga_afu_dma_region {
    u64 user_addr;
    u64 length;
    u64 iova;
    struct page **pages;
    struct rb_node node;
    bool in_use;
};

struct fpga_afu {
    u64 region_cur_offset;
    int num_regions;
    u8 num_umsgs;
    struct list_head regions;
    struct rb_root dma_regions;
    struct feature_platform_data *pdata;
};

Port Platform Device Initialization Flow

Port
  • afu_probe() afu_dev_init() * Initialize a struct fpga_afu and store it in the feature_platform_data.private field.
  • afu_probe() fpga_dev_feature_init() feature_instance_init() * Save a struct feature_ops into the feature_platform_data.features for each populated feature. * Call the test function, if any, from the struct. * Call the init function from the struct.
  • afu_probe() fpga_register_dev_ops() * Create the Port character device node, registering a struct file_operations.

FME IOCTLs

Call the following ioctls on an open file descriptor for /dev/intel-fpga-fme.*j*

FPGA_GET_API_VERSION

  • return the current version as an integer, starting from 0.

FPGA_CHECK_EXTENSION

  • (not currently supported).

FPGA_FME_PORT_RELEASE

  • arg is a pointer to a:
struct fpga_fme_port_release {
    __u32 argsz;   // in: sizeof(struct fpga_fme_port_release)
    __u32 flags;   // in: must be 0
    __u32 port_id; // in: port ID (from 0) to release.
};

FPGA_FME_PORT_ASSIGN

  • arg is a pointer to a:
struct fpga_fme_port_assign {
    __u32 argsz;   // in: sizeof(struct fpga_fme_port_assign)
    __u32 flags;   // in: must be 0
    __u32 port_id; // in: port ID (from 0) to assign. (must have been previously released by FPGA_FME_PORT_RELEASE)
};

FPGA_FME_PORT_PR

  • arg is a pointer to a:
struct fpga_fme_port_pr {
    __u32 argsz;          // in: sizeof(struct fpga_fme_port_pr)
    __u32 flags;          // in: must be 0
    __u32 port_id;        // in: port ID (from 0)
    __u32 buffer_size;    // in: size of bitstream buffer in bytes. Must be 4-byte aligned.
    __u64 buffer_address; // in: process address of bitstream buffer
    __u64 status;         // out: error status (bitmask)
};

Port IOCTLs

Call the following ioctls on an open file descriptor for /dev/intel-fpga-port.*k* .

FPGA_GET_API_VERSION

  • return the current version as an integer, starting from 0.

FPGA_CHECK_EXTENSION

  • (not currently supported).

FPGA_PORT_GET_INFO

  • arg is a pointer to a:
struct fpga_port_info {
    __u32 argsz;       // in: sizeof(struct fpga_port_info)
    __u32 flags;       // out: returns 0
    __u32 num_regions; // out: number of MMIO regions, 2 (1 for AFU and 1 for STP)
    __u32 num_umsgs;   // out: number of UMsg's supported by the hardware
};

FPGA_PORT_GET_REGION_INFO

  • arg is a pointer to a:
struct fpga_port_region_info {
    __u32 argsz;   // in: sizeof(struct fpga_port_region_info)
    __u32 flags;   // out: (bitmask) { FPGA_REGION_READ, FPGA_REGION_WRITE, FPGA_REGION_MMAP }
    __u32 index;   // in: FPGA_PORT_INDEX_UAFU or FPGA_PORT_INDEX_STP
    __u32 padding; // in: must be 0
    __u64 size;    // out: size of MMIO region in bytes
    __u64 offset;  // out: offset of MMIO region from start of device fd
};

FPGA_PORT_DMA_MAP

  • arg is a pointer to a:
struct fpga_port_dma_map {
    __u32 argsz;     // in: sizeof(struct fpga_port_dma_map)
    __u32 flags;     // in: must be 0
    __u64 user_addr; // in: process virtual address. Must be page aligned.
    __u64 length;    // in: length of mapping in bytes. Must be a multiple of page size.
    __u64 iova;      // out: IO virtual address
};

FPGA_PORT_DMA_UNMAP

  • arg is a pointer to a:
struct fpga_port_dma_unmap {
    __u32 argsz; // in: sizeof(struct fpga_port_dma_unmap)
    __u32 flags; // in: must be 0
    __u64 iova;  // in: IO virtual address returned by a previous FPGA_PORT_DMA_MAP
};

FPGA_PORT_RESET

  • arg must be NULL.

FPGA_PORT_UMSG_ENABLE

  • arg must be NULL.

FPGA_PORT_UMSG_DISABLE

  • args must be NULL.

FPGA_PORT_UMSG_SET_MODE

  • arg is a pointer to a:
struct fpga_port_umsg_cfg {
    __u32 argsz;       // in: sizeof(struct fpga_port_umsg_cfg)
    __u32 flags;       // in: must be 0
    __u32 hint_bitmap; // in: UMsg hint mode bitmap. Signifies which UMsg's are enabled.
};

FPGA_PORT_UMSG_SET_BASE_ADDR

  • Disable UMsg before issuing this ioctl.
  • The buffer for the iova field must large enough for all UMsg’s (num_umsgs * PAGE_SIZE). * The the driver’s buffer management marks this buffer “in use”. * If iova is NULL, the driver’s buffer management marks any previous region “in use”.
  • arg is a pointer to a:
struct fpga_port_umsg_base_addr {
    __u32 argsz; // in: sizeof(struct fpga_port_umsg_base_addr)
    __u32 flags; // in: must be 0
    __u64 iova;  // in: IO virtual address from FPGA_PORT_DMA_MAP.
};

To clear the port errors, write the exact bitmask of the current errors, for example:

$ cat errors > clear

sysfs files

The registers available on the Intel Programmable Acceleration Card (PAC) are a subset of the registers available on the Intel Xeon Processor with Integrated FPGA. When the registers available for the two platforms differ, the tables below include a fifth column to specify platform support. The tables use the following abbreviations:

  • Integrated FPGA - Intel Xeon Processor with Integrated FPGA
  • PAC - Intel Programmable Acceleration Card (PAC) ## FME Header sysfs files ##

intel-fpga-dev.i/intel-fpga-fme.*j*/

sysfs file mmio field type access
ports_num fme_header.capability.num_ports decimal int Read-only
cache_size fme_header.capability.cache_size decimal int Read-only
version fme_header.capability.fabric_verid decimal int Read-only
socket_id fme_header.capability.socket_id decimal int Read-only
bitstream_id fme_header.bitstream_id hex uint64_t Read-only
bitstream_metadata fme_header.bitstream_md hex uint64_t Read-only

FME Thermal Management sysfs files

intel-fpga-dev.i/intel-fpga-fme.*j*/thermal_mgmt/

sysfs file mmio field type access platform support
threshold1 thermal.threshold.tmp_thshold1 decimal int User: Read-only Root: Read-write Integrate d FPGA
threshold2 thermal.threshold.tmp_thshold2 decimal int User: Read-only Root: Read-write Integrate d FPGA
threshold_ trip thermal.threshold.ther m_trip_thshold decimal int Read-only Integrate d FPGA
threshold1_reached thermal.threshold.thsh old1_status decimal int Read-only Integrate d FPGA
threshold2_reached thermal.threshold.thsh old2_status decimal int Read-only Integrate d FPGA
threshold1_policy thermal.threshold.thsh old_policy decimal int User: Read-only Root: Read-write Integrate d FPGA
temperature thermal.rdsensor_fm1. fpga_temp decimal int Read-only Integrate d FPGA, PAC

FME Power Management sysfs files

Power management is available only for the Intel Xeon Processor with Integrated FPGA.

intel-fpga-dev.i/intel-fpga-fme.*j*/power_mgmt/

sysfs file mmio field type access
consumed power.status.pwr_consu med hex uint64_t Read-only
threshold1 power.threshold.thresho ld1 hex uint64_t User: Read-only Root: Read-write
threshold2 power.threshold.thresho ld2 hex uint64_t User: Read-only Root: Read-write
threshold1_s tatus power.threshold.thresho ld1_status decimal unsigned Read-only
threshold2_s tatus power.threshold.thresho ld2_status decimal unsigned Read-only
rtl power.status.fpga_late ncy_report decimal unsigned Read-only

FME Global Error sysfs files

intel-fpga-dev.i/intel-fpga-fme.*j*/errors/

sysfs file mmio field type access platform support
pcie0_errors gerror.pcie0_err hex uint64_t Read-wri te Integrated FPGA, PAC
pcie1_errors gerror.pcie1_err hex uint64_t Read-wri te Integrated FPGA
gbs_errors gerror.ras_gerr hex uint64_t Read-onl y Integrated FPGA, PAC
bbs_errors gerror.ras_berr hex uint64_t Read-onl y Integrated FPGA, PAC
warning_error s gerror.ras_werr.even t_warn_err hex int Read-wri te Integrated FPGA, PAC
inject_error gerror.ras_error_in j hex uint64_t Read-wri te Integrated FPGA, PAC

intel-fpga-dev.i/intel-fpga-fme.*j*/errors/fme-errors/

sysfs file mmio field type access
errors gerror.fme_err hex uint64_t Read-only
first_error gerror.fme_first_err.err_reg_status hex uint64_t Read-only
next_error gerror.fme_next_err.err_reg_status hex uint64_t Read-only
clear Clears errors, first_error, next_error various uint64_t Write-only 
To clear the FME errors, write the exact bitmask of the current errors, for example:

cat errors > clear

FME Partial Reconfiguration sysfs files

intel-fpga-dev.i/intel-fpga-fme.*j*/pr/

sysfs file mmio field type access
interface_i d pr.fme_pr_intfc_id0_h, pr.fme_pre_intfc_id0_l hex 16-byte Read-only

FME Global Performance sysfs files

intel-fpga-dev.i/intel-fpga-fme.*j*/dperf/clock

sysfs file mmio field type access
clock gperf.clk.afu_interf_clock hex uint64_t Read-only

intel-fpga-dev.i/intel-fpga-fme.*j*/perf/cache/ (Not valid for Acceleration Stack for Intel® Xeon® CPU with FPGAs)

sysfs file mmio field type access
freeze gperf.ch_ctl.freeze decimal int Read-write
read_hit gperf.CACHE_RD_HIT hex uint64_t Read-only
read_miss gperf.CACHE_RD_MISS hex uint64_t Read-only
write_hit gperf.CACHE_WR_HIT hex uint64_t Read-only
write_miss gperf.CACHE_WR_MISS hex uint64_t Read-only
hold_request gperf.CACHE_HOLD_REQ hex uint64_t Read-only
tx_req_stall gperf.CACHE_TX_REQ_STAL L hex uint64_t Read-only
rx_req_stall gperf.CACHE_RX_REQ_STAL L hex uint64_t Read-only
data_write_port_con tention gperf.CACHE_DATA_WR_POR T_CONTEN hex uint64_t Read-only
tag_write_port_cont ention gperf.CACHE_TAG_WR_PORT _CONTEN hex uint64_t Read-only

intel-fpga-dev.i/intel-fpga-fme.*j*/perf/iommu/

Power management is only available for the Intel Xeon Processor with Integrated FPGA.

sysfs file mmio field type access
freeze gperf.vtd_ctl.freeze decimal int User: Read-only Root: Read-write
intel-fpga-dev.i/intel-fpga-fme.*j*/perf/iommu/afu*k*/
Power management is only available for the Intel Xeon Processor with Integrated FPGA.
sysfs file mmio field type access
read_transaction gperf.VTD_AFU0_MEM_RD_TRANS hex uint64_t Read-only
write_transaction gperf.VTD_AFU0_MEM_WR_TRANS hex uint64_t Read-only
tlb_read_hit gperf.VTD_AFU0_TLB_RD_HIT hex uint64_t Read-only
tlb_write_hit gperf.VTD_AFU0_TLB_WR_HIT hex uint64_t Read-only

intel-fpga-dev.i/intel-fpga-fme.*j*/dperf/fabric/

sysfs file mmio field type access platform support
enable gperf.fab_ctl.( enabled) decimal int User: Read-only Root: Read-write Integrated FPGA, PAC
freeze gperf.fab_ctl.f reeze decimal int User: Read-only Root: Read-write Integrated FPGA, PAC
pcie0_re ad gperf.FAB_PCIE0 _RD hex uint64_t Read-only Integrated FPGA, PAC
pcie0_wr ite gperf.FAB_PCIE0 _WR hex uint64_t Read-only Integrated FPGA, PAC
pcie1_re ad gperf.FAB_PCIE1 _RD hex uint64_t Read-only Integrated FPGA
pcie1_wr ite gperf.FAB_PCIE1 _WR hex uint64_t Read-only Integrated FPGA
upi_read gperf.FAB_UPI_ RD hex uint64_t Read-only Integrated FPGA
upi_writ e gperf.FAB_UPI_ WR hex uint64_t Read-only Integrated FPGA

intel-fpga-ev.i/intel-fpga/fme.*j*/dperf/fabric/port*k*/

sysfs file mmio field type access Integrated FPGA
pcie0_read gperf.FAB_PCIE0_RD hex uint64_t Read-only Integrated FPGA, PAC
pcie0_write gperf.FAB_PCIE0_WR hex uint64_t Read-only Integrated FPGA, PAC
pcie1_read gperf.FAB_PCIE1_RD hex uint64_t Read-only Integrated FPGA
pcie1_write gperf.FAB_PCIE1_WR hex uint64_t Read-only Integrated FPGA
upi_read gperf.FAB_UPI_RD hex uint64_t Read-only Integrated FPGA
upi_write gperf.FAB_UPI_WR hex uint64_t Read-only Integrated FPGA

Port Header sysfs files

intel-fpga-dev.i/intel-fpga-port.*k*/

sysfs file mmio field type access
id port_header.capability.port_number decimal int Read-only
ltr port_header.control.latency_tolerance decimal int Read-only

Port AFU Header sysfs files

intel-fpga-dev.i/intel-fpga-port.*k*/

sysfs file mmio field type access
afu_id afu_header.guid hex 16-byte Read-only

Port Error sysfs files

intel-fpga-dev.i/intel-fpga-port.*k*/errors/

sysfs file mmio field type access
errors perror.port_error hex uint64_t Read-only
first_error perror.port_first_error hex uint64_t Read-only
first_malformed_req perror.malreq hex 16-byte Read-only
clear perror.(all errors) various uint64_t Write-only 
To clear the Port errors, write the exact bitmask of the current errors, for example:

cat errors > clear