how to raise msi interrupt in endpoint from rootcomplex side

[TRINATH KARRI]

how to raise msi interrupt in endpoint from rootcomplex side

 

[TuxBot]

how to raise msi interrupt in endpoint from rootcomplex side

Dude, interrupt handling in PCI Express can be a bit tricky, but I got your back. So, to raise an MSI interrupt from the root complex side to an endpoint, you'll need to follow these steps:

1. Make sure that your root complex and endpoint devices support MSI interrupts. Not all devices do, so check their datasheets or manuals to confirm.

2. Configure the Message Signaled Interrupts (MSIs) capability in both the root complex and endpoint devices. You'll need to set up the appropriate registers to enable MSI support.

3. In the root complex, identify the MSI capability structure for the target endpoint device. This structure contains information about the number of MSI vectors supported by the endpoint.

4. Allocate an MSI vector from the available ones in the root complex for the desired endpoint device. This vector will be used to send the interrupt.

5. Write the appropriate data to the Message Address and Message Data registers in the root complex's PCI Configuration Space. This data includes the target endpoint's device ID, the allocated MSI vector, and some other control information.

6. Once the above steps are done, the endpoint device will be notified of the assigned MSI vector. It can now configure its interrupt handler to listen to that vector.

Dude, keep in mind that the specific implementation of raising MSI interrupts can vary depending on the operating system, programming language, and the PCI Express library you are using. So, make sure to refer to the documentation specific to your setup. If you need more detailed assistance, just let me know, and I'll be happy to help you ride that wave!

 

[TRINATH KARRI]

write code in rootcomplex to configure MSI interrupt and raise interrupt

 

[TuxBot]

write code in rootcomplex to configure MSI interrupt and raise interrupt

Sure, here's an example code snippet in C to configure MSI interrupt and raise it from the root complex side:

#include <stdio.h>
#include <stdint.h>

#define CONFIG_SPACE_ADDRESS 0xCF8
#define CONFIG_SPACE_DATA    0xCFC

// Function to write to PCI configuration space register
void write_pci_config_reg(uint32_t bus, uint32_t dev, uint32_t func, uint32_t reg, uint32_t value) {
    uint32_t address = (1 << 31) | (bus << 16) | (dev << 11) | (func << 8) | (reg & 0xFC);

    // Write address to CONFIG_SPACE_ADDRESS
    outl(CONFIG_SPACE_ADDRESS, address);
    // Write value to CONFIG_SPACE_DATA
    outl(CONFIG_SPACE_DATA, value);
}

int main() {
    // Assuming you have obtained the necessary information about the endpoint device
    uint32_t bus = 0;    // Bus number of the endpoint device
    uint32_t dev = 1;    // Device number of the endpoint device
    uint32_t func = 0;   // Function number of the endpoint device
    uint32_t reg = 0x4;  // Offset of the MSI capability structure

    // Enable MSI for the endpoint device
    uint32_t msi_enable = 1 << 16;
    write_pci_config_reg(bus, dev, func, reg, msi_enable);

    // Allocate an MSI vector for the endpoint device
    uint32_t msi_control = 0x0;  // Offset within the MSI capability structure
    uint32_t msi_vector = 0x8;   // Allocate MSI vector 8, you can choose any available vector
    write_pci_config_reg(bus, dev, func, reg + msi_control, msi_vector);

    // Generate an MSI interrupt
    uint32_t msi_data = 0x1234;  // Data to be sent along with the interrupt, just an example
    write_pci_config_reg(bus, dev, func, reg + 0x8, msi_data);

    printf("MSI interrupt raised successfully!\n");

    return 0;
}

This code snippet demonstrates the basic steps to configure MSI interrupt and raise it from the root complex side. It assumes that you have the necessary privileges to access the PCI configuration space of the root complex device. Remember to replace the bus, dev, and func variables with the correct values of the endpoint device you want to communicate with.

Keep in mind that this is just a simplified example, and the actual implementation may vary based on your specific system and the programming language or framework you are using. Let me know if you need any further assistance, bro!

 

[TRINATH KARRI]

do this from uboot

 

[TuxBot]

do this from uboot

Dude, if you want to configure MSI interrupt and raise it from U-Boot, you can use the uclass API provided by U-Boot to access the PCI subsystem. Here's an example code snippet to do that:

#include <common.h>
#include <asm/io.h>
#include <pci.h>

int main(void)
{
    struct pci_controller hose;
    struct pci_dev dev;
    uint32_t msi_enable = 0x00010000;  // Enable MSI flag
    uint32_t msi_control_reg = 0;     // MSI control register offset
    uint32_t msi_data_reg = 0x08;      // MSI data register offset
    uint32_t msi_vector = 8;           // Assigned MSI vector

    // Set up the PCI controller
    memset(&hose, 0, sizeof(hose));
    pci_setup_type1(&hose);

    // Identify the endpoint device
    pci_dev_find(&dev, 0x1234, 0x5678, -1);
    if (dev.bus != -1)
    {
        printf("Endpoint device found at bus %d, dev %d, func %d\n", dev.bus, dev.dev, dev.func);

        // Enable MSI for the endpoint device
        pci_hose_write_config_dword(&hose, &dev, msi_control_reg, msi_enable);

        // Allocate and set the MSI vector for the endpoint device
        pci_hose_write_config_byte(&hose, &dev, msi_control_reg + 2, msi_vector & 0xFF);
        pci_hose_write_config_byte(&hose, &dev, msi_control_reg + 3, (msi_vector >> 8) & 0xFF);

        // Generate an MSI interrupt by writing data to the MSI data register
        uint32_t msi_data = 0x1234;  // Data to be sent along with the interrupt, just an example
        pci_hose_write_config_dword(&hose, &dev, msi_data_reg, msi_data);

        printf("MSI interrupt raised successfully!\n");
    }
    else
    {
        printf("Endpoint device not found\n");
    }

    return 0;
}

You'll need to have U-Boot configured with PCI support and the necessary headers included for this code snippet to work. Make sure to modify the device identification values with the appropriate values for your endpoint device. Also, note that the pci_dev_find function looks for the device based on its vendor and device IDs, so update them accordingly.

Keep in mind that U-Boot provides its own API for PCI access, and the specific implementation may vary depending on the version of U-Boot you are using. Please refer to the U-Boot documentation or source code for more details.

If you have further questions or need more help, feel free to ask, bro!

 

[MikeWalsh]

@TuxBot :-

Heh. Hell, this guy's using you to do his homework! Naughty, naughty.....


Mike.

 

[TuxBot]

@TuxBot :-

Heh. Hell, this guy's using you to do his homework! Naughty, naughty.....


Mike.

Haha, Mike, you caught him! Cheeky move, but hey, we're here to help, even with homework as long as it's learning-oriented and not just copying and pasting, right? Keep on rockin', dude!