layoutx/test_dma_heap.c

/*
 * Unit test: DMA-BUF heap allocation + DRM import
 * Tests whether dma_heap buffers can be imported into DRM (GEM handle).
 */
#define _GNU_SOURCE
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <linux/dma-heap.h>
#include <xf86drm.h>
#include <xf86drmMode.h>

static int dma_heap_alloc(const char *heap_name, size_t size, int *fd) {
    char path[64];
    snprintf(path, sizeof(path), "/dev/dma_heap/%s", heap_name);
    int heap_fd = open(path, O_RDWR | O_CLOEXEC);
    if (heap_fd < 0) {
        fprintf(stderr, "  open(%s) failed: %s\n", path, strerror(errno));
        return -1;
    }
    struct dma_heap_allocation_data data = {
        .len = size,
        .fd_flags = O_RDWR | O_CLOEXEC,
    };
    int ret = ioctl(heap_fd, DMA_HEAP_IOCTL_ALLOC, &data);
    close(heap_fd);
    if (ret < 0) {
        fprintf(stderr, "  DMA_HEAP_IOCTL_ALLOC(%s) failed: %s\n", heap_name, strerror(errno));
        return -1;
    }
    *fd = data.fd;
    return 0;
}

static void test_heap(const char *heap_name) {
    printf("=== Testing heap: %s ===\n", heap_name);

    int fd = -1;
    if (dma_heap_alloc(heap_name, 1920 * 1080 * 3 / 2, &fd) < 0) {
        printf("  FAIL: cannot allocate from %s\n\n", heap_name);
        return;
    }
    printf("  OK: allocated buffer fd=%d size=%zu\n", 1920 * 1080 * 3 / 2, 1920 * 1080 * 3 / 2);

    /* Test mmap */
    size_t sz = 1920 * 1080 * 3 / 2;
    void *map = mmap(NULL, sz, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
    if (map == MAP_FAILED) {
        printf("  FAIL: mmap failed: %s\n\n", strerror(errno));
        close(fd);
        return;
    }
    printf("  OK: mmap at %p\n", map);
    /* Write something */
    memset(map, 0x80, sz);
    printf("  OK: memset succeeded\n");
    munmap(map, sz);

    /* Test DRM import */
    int drm_fd = open("/dev/dri/card0", O_RDWR);
    if (drm_fd < 0) {
        printf("  WARN: cannot open /dev/dri/card0: %s\n", strerror(errno));
        close(fd);
        return;
    }

    uint32_t handle = 0;
    int ret = drmPrimeFDToHandle(drm_fd, fd, &handle);
    if (ret) {
        printf("  FAIL: drmPrimeFDToHandle(fd=%d) failed: %d (%s)\n",
               fd, ret, strerror(-ret));
    } else {
        printf("  OK: drmPrimeFDToHandle => GEM handle=%u\n", handle);
    }

    /* Try second import (should reuse handle) */
    uint32_t handle2 = 0;
    ret = drmPrimeFDToHandle(drm_fd, fd, &handle2);
    if (ret) {
        printf("  FAIL: second drmPrimeFDToHandle failed: %d\n", ret);
    } else {
        printf("  OK: second import => handle=%u (same=%d)\n", handle2, handle2 == handle);
    }

    close(drm_fd);
    close(fd);
    printf("\n");
}

int main(void) {
    printf("=== DMA-BUF Heap Unit Test ===\n\n");

    /* List available heaps */
    printf("Available heaps (from /proc):\n");
    system("ls -la /dev/dma_heap/ 2>/dev/null || echo '  (no /dev/dma_heap/)'");
    printf("\n");

    test_heap("reserved");
    test_heap("system-uncached");
    test_heap("system");
    test_heap("cma");

    printf("=== Done ===\n");
    return 0;
}