Multi Channel DMA Intel® FPGA IP for PCI Express User Guide

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ID 683821
Date 11/01/2022
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Document Table of Contents
Document Table of Contents x
1. Before You Begin 2. Introduction 3. Functional Description 4. Interface Overview 5. Parameters (H-Tile) 6. Parameters (P-Tile and F-Tile) 7. Designing with the IP Core 8. Software Programming Model 9. Registers 10. Troubleshooting/Debugging 11. Multi Channel DMA Intel FPGA IP for PCI Express User Guide Archives 12. Revision History for Multi Channel DMA Intel FPGA IP for PCI Express User Guide
1. Before You Begin x
1.1. Terms and Acronyms 1.2. Known Issues
2. Introduction x
2.1. Multi Channel DMA IP for PCI Express Features 2.2. Device Family Support 2.3. Recommended Speed Grades 2.4. Resource Utilization 2.5. Release Information
2.1. Multi Channel DMA IP for PCI Express Features x
2.1.1. Endpoint Mode 2.1.2. Root Port Mode
3. Functional Description x
3.1. Multi Channel DMA 3.2. Bursting Avalon-MM Master (BAM) 3.3. Bursting Avalon-MM Slave (BAS) 3.4. MSI Interrupt 3.5. Config Slave (CS) 3.6. Root Port Address Translation Table Enablement 3.7. Hard IP Reconfiguration Interface 3.8. Config TL Interface 3.9. Configuration Intercept Interface (EP Only) 3.10. Data Mover Only
3.1. Multi Channel DMA x
3.1.1. H2D Data Mover 3.1.2. D2H Data Mover 3.1.3. Descriptors 3.1.4. Avalon-MM PIO Master 3.1.5. Avalon-MM Write (H2D) and Read (D2H) Master 3.1.6. Avalon-ST Source (H2D) and Sink (D2H) 3.1.7. User MSI-X 3.1.8. User Functional Level Reset (FLR) 3.1.9. Control Registers
3.1.2. D2H Data Mover x
3.1.2.1. D2H Descriptor Fetch
3.1.3. Descriptors x
3.1.3.1. Support for Unaligned (or byte-aligned) Data Transfer 3.1.3.2. Metadata Support 3.1.3.3. MSI-X/Writeback
3.1.6. Avalon-ST Source (H2D) and Sink (D2H) x
3.1.6.1. Avalon-ST 1-Port Mode 3.1.6.2. Packet (File) Boundary 3.1.6.3. Metadata
3.4. MSI Interrupt x
3.4.1. Endpoint MSI Support through BAS 3.4.2. MSI Interrupt Controller
3.5. Config Slave (CS) x
3.5.1. 29 bit AVMM address format 3.5.2. 14 bit AVMM address format 3.5.3. Configuration Access Mechanism
3.10. Data Mover Only x
3.10.1. H2D Data Mover 3.10.2. D2H Data Mover 3.10.3. Application Specific Bits
3.10.1. H2D Data Mover x
3.10.1.1. H2D Descriptor Format (h2ddm_desc) 3.10.1.2. H2D Descriptor Completion Packet Format (h2ddm_desc_cmpl) 3.10.1.3. H2D Descriptor Status (h2ddm_desc_status)
3.10.2. D2H Data Mover x
3.10.2.1. D2H Descriptor Format (d2hdm_desc) 3.10.2.2. D2H Descriptor Status (d2hdm_desc_status)
4. Interface Overview x
4.1. Port List 4.2. Clocks 4.3. Resets 4.4. Multi Channel DMA 4.5. Bursting Avalon-MM Master (BAM) Interface 4.6. Bursting Avalon-MM Slave (BAS) Interface 4.7. MSI Interface (EP) 4.8. Config Slave Interface (RP only) 4.9. Hard IP Reconfiguration Interface 4.10. Config TL Interface 4.11. Configuration Intercept Interface (EP Only) 4.12. Data Mover Interface 4.13. Hard IP Status Interface
4.1. Port List x
4.1.1. Port List (H-Tile) 4.1.2. Port List (P-Tile and F-Tile)
4.4. Multi Channel DMA x
4.4.1. Avalon-MM PIO Master 4.4.2. Avalon-MM Write Master (H2D) 4.4.3. Avalon-MM Read Master (D2H) 4.4.4. Avalon-ST Source (H2D) 4.4.5. Avalon-ST Sink (D2H) 4.4.6. User Event MSI-X Interface 4.4.7. User Functional Level Reset (FLR) Interface
4.12. Data Mover Interface x
4.12.1. H2D Data Mover Interface 4.12.2. D2H Data Mover Interface
5. Parameters (H-Tile) x
5.1. IP Settings 5.2. Example Designs
5.1. IP Settings x
5.1.1. System Settings 5.1.2. MCDMA Settings 5.1.3. Device Identification Registers 5.1.4. Multifunction and SR-IOV System Settings Parameters [Endpoint Mode] 5.1.5. Configuration, Debug and Extension Options 5.1.6. PHY Characteristics 5.1.7. PCI Express / PCI Capabilities Parameters
5.1.7. PCI Express / PCI Capabilities Parameters x
5.1.7.1. Device 5.1.7.2. Link 5.1.7.3. MSI-X 5.1.7.4. Power Management 5.1.7.5. Vendor Specific Extended Capability (VSEC)
6. Parameters (P-Tile and F-Tile) x
6.1. Top-Level Settings 6.2. PCIe0 Settings 6.3. PCIe1 Settings 6.4. Example Designs
6.2. PCIe0 Settings x
6.2.1. Base Address Register 6.2.2. PCIe0 Configuration, Debug and Extension Options 6.2.3. PCIe0 Device Identification Registers 6.2.4. PCIe0 PCI Express / PCI Capabilities Parameters 6.2.5. MCDMA Settings
6.2.3. PCIe0 Device Identification Registers x
6.2.3.1. PCIe0 PF0 IDs 6.2.3.2. PCIe0 PF0 VF IDs
6.2.4. PCIe0 PCI Express / PCI Capabilities Parameters x
6.2.4.1. PCIe0 Device 6.2.4.2. PCIe0 Link 6.2.4.3. PCIe0 MSI-X 6.2.4.4. PCIe0 DEV SER 6.2.4.5. PCIe0 PRS 6.2.4.6. PCIe0 ACS Capabilities 6.2.4.7. PCIe0 ATS 6.2.4.8. PCIe0 TPH
6.2.4.6. PCIe0 ACS Capabilities x
6.2.4.6.1. PCIe0 ACS for Physical Functions 6.2.4.6.2. PCIe0 ACS for Virtual Functions
6.2.4.7. PCIe0 ATS x
6.2.4.7.1. PCIe0 ATS for Physical Functions 6.2.4.7.2. PCIe0 ATS for Virtual Functions
6.2.4.8. PCIe0 TPH x
6.2.4.8.1. PCIe0 TPH for Physical Functions 6.2.4.8.2. PCIe0 TPH for Virtual Functions
6.3. PCIe1 Settings x
6.3.1. PCIe1 Configuration, Debug and Extension Options
7. Designing with the IP Core x
7.1. Generating the IP Core 7.2. Simulating the IP Core 7.3. IP Core Generation Output - Intel® Quartus® Prime Pro Edition 7.4. Systems Integration and Implementation
7.4. Systems Integration and Implementation x
7.4.1. Required Supporting IP
8. Software Programming Model x
8.1. Multi Channel DMA IP Custom Driver 8.2. Multi Channel DMA IP DPDK Poll-Mode based Driver 8.3. Multi Channel DMA IP Kernel Mode Character Device Driver 8.4. Multi Channel DMA IP Kernel Mode Network Device Driver
8.1. Multi Channel DMA IP Custom Driver x
8.1.1. Architecture 8.1.2. libmqdma library details 8.1.3. Application 8.1.4. Software Flow 8.1.5. API Flow 8.1.6. libmqdma Library API List 8.1.7. Request Structures
8.1.2. libmqdma library details x
8.1.2.1. Channel Initialization 8.1.2.2. Descriptor Memory Management 8.1.2.3. Descriptor Completion Status Update
8.1.5. API Flow x
8.1.5.1. Single Descriptor Load and Submit 8.1.5.2. Multiple Descriptor Load and Submit
8.1.6. libmqdma Library API List x
8.1.6.1. ifc_api_start 8.1.6.2. ifc_mcdma_port_by_name 8.1.6.3. ifc_qdma_device_get 8.1.6.4. ifc_num_channels_get 8.1.6.5. ifc_qdma_channel_get 8.1.6.6. ifc_qdma_acquire_channels 8.1.6.7. ifc_qdma_release_all_channels 8.1.6.8. ifc_qdma_device_put 8.1.6.9. ifc_qdma_channel_put 8.1.6.10. ifc_qdma_completion_poll 8.1.6.11. ifc_qdma_request_start 8.1.6.12. ifc_qdma_request_prepare 8.1.6.13. ifc_qdma_descq_queue_batch_load 8.1.6.14. ifc_qdma_request_submit 8.1.6.15. ifc_qdma_pio_read32 8.1.6.16. ifc_qdma_pio_write32 8.1.6.17. ifc_qdma_pio_read64 8.1.6.18. ifc_qdma_pio_write64 8.1.6.19. ifc_qdma_pio_read128 8.1.6.20. ifc_qdma_pio_write128 8.1.6.21. ifc_qdma_pio_read256 8.1.6.22. ifc_qdma_pio_write256 8.1.6.23. ifc_request_malloc 8.1.6.24. ifc_request_free 8.1.6.25. ifc_app_stop 8.1.6.26. ifc_qdma_poll_init 8.1.6.27. ifc_qdma_poll_add 8.1.6.28. ifc_qdma_poll_wait 8.1.6.29. ifc_mcdma_port_by_name
8.2. Multi Channel DMA IP DPDK Poll-Mode based Driver x
8.2.1. Architecture 8.2.2. MCDMA Poll Mode Driver 8.2.3. DPDK based application 8.2.4. Request Structures 8.2.5. Software Flow 8.2.6. API Flow 8.2.7. API List
8.2.2. MCDMA Poll Mode Driver x
8.2.2.1. Completion Status Update 8.2.2.2. Metadata Support 8.2.2.3. User MSI-X
8.3. Multi Channel DMA IP Kernel Mode Character Device Driver x
8.3.1. Architecture 8.3.2. libmcmem Library Information 8.3.3. Kernel Driver Information 8.3.4. Control Message Structure 8.3.5. Software Flow Step 1 Step 2 Step 3 Step 4 Step 5 Step 6 Step 7 8.3.6. API Flow 8.3.7. API List
8.3.3. Kernel Driver Information x
8.3.3.1. Device Management 8.3.3.2. Channel Management 8.3.3.3. Completions Management
8.3.3.3. Completions Management x
8.3.3.3.1. Interrupt Mode 8.3.3.3.2. Poll Mode
8.4. Multi Channel DMA IP Kernel Mode Network Device Driver x
8.4.1. Architecture 8.4.2. Driver Information 8.4.3. Software Flow
8.4.2. Driver Information x
8.4.2.1. Device Management 8.4.2.2. Channel Management 8.4.2.3. Descriptor Memory Management 8.4.2.4. Completions Management 8.4.2.5. ethtool support 8.4.2.6. debugfs support 8.4.2.7. SRIOV Support
8.4.3. Software Flow x
8.4.3.1. Host to Device Flow 8.4.3.2. Device to Host Flow
9. Registers x
9.1. Queue Control (QCSR) 9.2. MSI-X Memory Space 9.3. Control Register (GCSR)
10. Troubleshooting/Debugging x
10.1. Debug Toolkit
10.1. Debug Toolkit x
10.1.1. Overview 10.1.2. Enabling the Debug Toolkit 10.1.3. Launching the Debug Toolkit 10.1.4. Using the Debug Toolkit
10.1.4. Using the Debug Toolkit x
10.1.4.1. Main View 10.1.4.2. Toolkit Parameters 10.1.4.3. Channel Parameters 10.1.4.4. Eye Viewer 10.1.4.5. Link Inspector
1. Before You Begin
2. Introduction
3. Functional Description
4. Interface Overview
5. Parameters (H-Tile)
6. Parameters (P-Tile and F-Tile)
7. Designing with the IP Core
8. Software Programming Model
9. Registers
10. Troubleshooting/Debugging
11. Multi Channel DMA Intel FPGA IP for PCI Express User Guide Archives
12. Revision History for Multi Channel DMA Intel FPGA IP for PCI Express User Guide

8.3.5. Software Flow

Figure 55. Kernel Mode Driver Software Flow

Step 1

  • Application initializes the Libmcmem library & uses the library APIs to receive DMA memory
  • Libmcmem, as part of initialization allocates huge pages & sets them up into smaller chunks. It allocates these chunks to the application as per request.

Step 2

  • Application requests for channel through the character device. Kernel module driver receives the request and allocates an available channel. If all channels are busy, the request are not be served.
  • Application as part of initialization also provides the kernel driver with eventfds, payload size per descriptor & file size (optional) using a control message.
  • The eventfds are used by the driver to notify the application regarding the completion of DMA requests.
  • Kernel Driver initializes following registers which includes Starting address of descriptors, queue size, write back address for consumed Head, payload size in D2H descriptors as part of the channel initialization.
  • QCSR registers:
    • Q_RESET (offset 8’h48)
    • Q_TAIL_POINTER (offset 8’h14) Set 0
    • Q_START_ADDR_L (Offset 8’h08)
    • Q_START_ADDR_H (Offset 8’h0C)
    • Q_SIZE (Offset 8’h10)
    • Q_CONSUMED_HEAD_ADDR_L (Offset 8’h20)
    • Q_CONSUMED_HEAD_ADDR_H (Offset 8’h24)
    • Q_BATCH_DELAY (Offset 8’h28)
    • Set q_en, q_wb/intr_en bits, Q_CTRL (Offset 8’h00)
    • (Q_PYLD_COUNT) (Offset 8'h44)
  • GCSR register:
    • WB_INTR_DELAY (Offset 8’h08)
  • It also sets up interrupt handlers for processing of MSIX signals, eventfds for forwarding completion events to the application
  • Application submits the DMA transfer requests to the driver through read/write APIs

Step 3

  • Hardware supports request descriptors for submission of requests. Kernel module manages a ring of descriptors for request submissions.
  • Each request received from the application is transformed into a descriptor & pushed into the descriptor ring
  • The descriptor contains the starting physical address of the DMA buffer allocated in Step 1
  • If channel is not busy and descriptor ring is not full it goes to step 3
  • If channel is busy or descriptors ring is full, the thread retries to initiate the transfer.

Step 4

  • The submission of the descriptor is done through updation of tail pointer FIFO of the FPGA logic
  • QCSR tail pointer register Q_TAIL_POINTER (Offset 8’h14) is updated by one.

Step 5

  • Once the tail pointer write happens, QDMA IP fetches the descriptors from host memory starting from the programmed Q_START_ADDR_L/H address.
  • QDMA IP parses the descriptor content to find the sources, destination addresses and length of the data from descriptor and starts DMA operation.

Step 6

  • Once descriptor processing is completed, IP notifies the completion status based on following methods.
  • Following are two different ways for completion status indication, which can be enabled in each descriptor.
    • Either based on MSI-X Interrupt : QDMA IP sends MSI-X interrupt to host if enabled in Q_CTRL.
    • Writeback: QDMA IP updates Q_CONSUMED_HEAD_ADDR_L/H, if writeback is enabled in Q_CTRL.

Step 7

  • In case of MSI-X Interrupt, interrupt handler of the kernel driver processes the signal and passes the count of completed requests to the application via eventfds
  • In case of Writeback, the application polls the character device to check on the completed requests. The driver passes the count of completed requests to the application via eventfds.
Level Two Title