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

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ID 683821
Date 4/20/2022
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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. Config Slave 3.5. Hard IP Reconfiguration Interface 3.6. Config TL Interface 3.7. Configuration Intercept Interface (EP Only) 3.8. 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. Metadata Support 3.1.3.2. MSI-X/Writeback
3.1.6. Avalon-ST Source (H2D) and Sink (D2H) x
3.1.6.1. Avalon-ST 4-Port mode 3.1.6.2. Avalon-ST 1-Port Mode 3.1.6.3. Packet (File) Boundary 3.1.6.4. Metadata
3.8. Data Mover Only x
3.8.1. H2D Data Mover 3.8.2. D2H Data Mover 3.8.3. Application Specific Bits
3.8.1. H2D Data Mover x
3.8.1.1. H2D Descriptor Format (h2ddm_desc) 3.8.1.2. H2D Descriptor Completion Packet Format (h2ddm_desc_cmpl) 3.8.1.3. H2D Descriptor Status (h2ddm_desc_status)
3.8.2. D2H Data Mover x
3.8.2.1. D2H Descriptor Format (d2hdm_desc) 3.8.2.2. 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. Config Slave Interface (RP only) 4.8. Hard IP Reconfiguration Interface 4.9. Config TL Interface 4.10. Configuration Intercept Interface (EP Only) 4.11. User Functional Level Reset (FLR) 4.12. User Event MSI-X Request Interface 4.13. Data Mover Interface 4.14. 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 MSI-X Interface 4.4.7. User FLR Interface
4.13. Data Mover Interface x
4.13.1. H2D Data Mover Interface 4.13.2. 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. IP Settings 6.2. PCIe0 Settings 6.3. Example Designs
6.1. IP Settings x
6.1.1. Top-Level Settings
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
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 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 P-Tile Debug Toolkit 10.1.3. Launching the P-Tile Debug Toolkit 10.1.4. Using the P-Tile Debug Toolkit
10.1.4. Using the P-Tile 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
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

3.1.3. Descriptors

A DMA channel to support Multi Channel DMA data movement consists of a pair of the descriptor queues: one H2D descriptor queue and one D2H descriptor queue. Descriptors are arranged contiguously within a 4 KB page.

Each descriptor is 32 bytes in size. The descriptors are kept in host memory in a linked-list of 4 KB pages. For a 32 byte descriptor and a 4 KB page, each page contains upto 128 descriptors. The last descriptor in a 4 KB page must be a “link descriptor” – a descriptor containing a link to the next 4 KB page with the link bit set to 1. The last entry in the linked list must be a link pointing to the base address programmed in the QCSR, in order to achieve a circular buffer containing a linked-list of 4 KB pages. The figure below shows the descriptor linked list.

Figure 3. Descriptor Linked-List

Software and hardware communicate and manage the descriptors using tail index pointer (Q_TAIL_POINTER) and head index pointer (Q_HEAD_POINTER) QCSR registers as shown in the following figure. The DMA starts when software writes the last valid descriptor index to the Q_TAIL_POINTER register.

Figure 4. Descriptor Ring Buffer
Table 16.  Software Descriptor Format
Name Width Description
SRC_ADDR [63:0] 64

If Link bit =0, then this field contains the source address.

Starting system address of allocated transmit buffer read by DMA that should be 64 byte aligned.

If the queue is H2D, then this field contains the address in Host Memory. If the queue is D2H, then this is the AVMM address in device memory.

If the link bit is set, then this contains the address of the next 4 KB page in host memory containing the descriptors.

DEST_ADDR [127:64] 64

Provided link=0, this field means:

Starting system address of allocated receive buffer written by DMA that should be 64 byte aligned.

If the queue is D2H, then this field contains the address in Host Memory. If the queue is H2D, then this is the AVMM address in device memory.

PYLD_CNT [147:128] 20

Provided link=0, this field means DMA payload size in bytes. Max 1 MB, with 20’h0 indicating 1 MB.

For a D2H queue in 1 port AVST mode, this field is a fixed value across all descriptors of the queue and must reflect the value in Q_PYLD_CNT (0x44) QCSR register.

RSRVD [159:148] 12 Reserved
DESC_IDX [175:160] 16

Unique Identifier for each descriptor, assigned by the software driver. This value is written to Q_COMPLETED_POINTER register when a descriptor data transfer is complete.

Note: First descriptor DESC_IDX value is 1, not 0.
MSIX_EN [176] 1 Enable MSI-X per descriptor
WB_EN [177] 1 Enable Write Back per descriptor
RSRVD [191:178] 14 Reserved
RX_PYLD_CNT [211:192] 20 Received actual payload for D2H data movement (upstream)
RSRVD [221:212] 10 Reserved
SOF [222] 1

SOF indicator for Avalon-ST streaming.

In the H2D streaming, this bit causes the Avalon-ST Source interface to assert h2d_st_sof_o, indicating start of a file/packet.

In the D2H streaming, this bit is set in the Descriptor itself, by MWr TLP when the user logic asserts d2h_st_sof_i, indicating start of a file/packet.

Note: In the H2D streaming, both SOF and EOF can be set in the same descriptor (file size = payload count) or it can span multiple descriptor pages.
Note: In the D2H streaming, if user logic prematurely ends the data transfer by asserting d2h_st_eof_i in the middle of a descriptor data move then starts a next file/packet, the SOF bit in the next descriptor is set by MWr TLP.
Note: SOF bit is an optional feature for DMAs involving file data transfers using Avalon-ST interface.
EOF [223] 1

EOF indicator for Avalon-ST streaming.

In the H2D streaming, this bit causes the Avalon-ST Source interface to assert h2d_st_eof_o, indicating end of a file/packet.

In the D2H streaming, this bit is set within the descriptor itself by a Writeback (if Writeback is enabled) when the user logic asserts d2h_st_eof_i, indicating end of a packet.

Along with the EOF bit, MWr TLP also updates the actual received payload count (RX_PYLD_CNT) field of the last descriptor.

Note: EOF bit is an optional feature for DMAs involving file data transfers using Avalon-ST interface.
RSRVD [253:224] 30 Reserved
DESC_INVALID [254] 1 Indicates if current descriptor content is valid or stale
LINK [255] 1

Link =0

Descriptor contains the source address, destination address and length.

Link = 1

Descriptor contains the address of the next 4 KB page in host memory containing the descriptors.


Section Content
Metadata Support
MSI-X/Writeback

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