Code to reproduce the write-back/uncache-minus memory mismatch in aes-stream-drivers

kernel-warnings.cpp

#include "getopt.h"

#include <stdlib.h>
#include <stdio.h>
#include <string.h>

#include "DmaDriver.h"

#define AXI_VERSION_OFFSET 0x20000

#define DMA_MAP

int main(int argc, char** argv)
{
    char dev[256] = "/dev/datagpu_0";
    int o = 0;
    while ((o = getopt(argc, argv, "d:")) != -1) {
        switch (o) {
        case 'd':
            strcpy(dev, optarg);
            break;
        default:
            break;
        }
    }

    printf("Opening %s\n", dev);

    int fd;
    if ((fd = open(dev, O_RDWR)) < 0) {
        perror("Could not open device");
        return -1;
    }

    uint32_t count, size;
    auto** buffs = dmaMapDma(fd, &count, &size);
    if (!buffs || buffs == MAP_FAILED) {
        perror("dmaMapDma failed");
        exit(1);
    }

    // This is unnecessary, but done for testing. you should see warnings immediately after the memory is mapped.
    for (int b = 0; b < count; ++b) {
        auto* buf = (uint8_t*)buffs[b];
        for (int i = 0; i < size; ++i) {
            buf[i] = 0xAA;
        }

        for (int i = 0; i < size; ++i) {
            if (buf[i] != 0xAA) {
                printf("Bad b=%d, i=%d\n", b,i);
            }
        }
    }
    dmaUnMapDma(fd, buffs);

    close(fd);

    return 0;
}