MSI with avalonMM-DMA ip

[OlegT]

Hello.
I use pcie HIP with avalon-mm-dma interface, as an endpoint. Cyclone10GX evaluation kit.
I need to send custom MSI to root complex (ubuntu PC).
rxm_irq signals are not available due to mm-dma interface.
1. As I understand, I have to collect data from MSIIntfc_o[81:0] and send TLP via TXS port.
Am I right?

2. MSIIntfc_o contains an information about only one MSI vector.If I want to use more vectors, how can I get address and data to generate TLPs for other vectors?

Thank you.

[KhaiChein_Y_Intel]

Hi,

1. Yes. You have to use this interface to receive information required to generate MSI interrupts to the Root Port via the TX Slave interface.

2. You have to design a Custom Interrupt Handler. You may refer to Figure 51 for an overview of the logic for the Custom Interrupt Handler. The Custom Interrupt Handler should include hardware to perform the following tasks:

• An MSI/MSI-X IRQ Avalon-MM Master port to drive MSI or MSI-X interrupts as
  memory writes to the PCIe Avalon-MM bridge.
• A legacy interrupt signal, IntxReq_i, to drive legacy interrupts from the MSI/
  MSI-X IRQ module to the Hard IP for PCI Express.
• An MSI/MSI-X Avalon-MM Slave port to receive interrupt control and status from
  the PCIe Root Port.
• An MSI-X table to store the MSI-X table entries. The PCIe Root Port sets up this
  table.

https://www.intel.com/content/dam/www/programmable/us/en/pdfs/literature/ug/ug_a10_pcie_avmm.pdf

Thanks

Best regards,

KhaiY

[OlegT]

As I've found in docs, the MSI vectors differ only in LSBits of data field. All of them use the same address. 

Data field should be masked accordingly to count of vectors (2 - 0xFE, 4 - 0xFC, 8 - 0xF8 and so on) and then OR-ed with vector number.

Is it true?

[KhaiChein_Y_Intel · Accepted solution]

Hi,

I could not find the part that you have mentioned in the document. May I know which document you are referring to?

According to the PCI Local Bus Specification 2.3,

"If the Multiple Message Enable field (bits 6-4 of the Message Control register) is non-zero, the device is permitted to modify the low order bits of the message data to generate multiple messages."

Thanks

Best regards,

KhaiY

[OlegT]

Thank you, 

We are talking about same things.

[KhaiChein_Y_Intel]

Hi,

I’m glad that your question has been addressed, I now transition this thread to community support. If you have a new question, feel free to open a new thread to get the support from Intel experts. Otherwise, the community users will continue to help you on this thread. Thank you.

Best regards,

KhaiY