[PATCH 1/5] drm: add interface to get drm devices on the system v2
Daniel Vetter
daniel at ffwll.ch
Thu Aug 13 08:07:55 PDT 2015
On Thu, Aug 13, 2015 at 11:33:41AM +0800, Jammy Zhou wrote:
> From: Emil Velikov <emil.l.velikov at gmail.com>
>
> For mutiple GPU support, the devices on the system should be enumerated
> to get necessary information about each device, and the drmGetDevices
> interface is added for this. Currently only PCI devices are supported for
> the enumeration.
>
> Typical usage:
> int count;
> drmDevicePtr *foo;
> count = drmGetDevices(NULL, 0);
> foo = calloc(count, sizeof(drmDevicePtr));
> count = drmGetDevices(foo, count);
> /* find proper device, open correct device node, etc */
> drmFreeDevices(foo, count);
> free(foo);
>
> v2: change according to feedback from Emil
>
> Signed-off-by: Jammy Zhou <Jammy.Zhou at amd.com>
> ---
> xf86drm.c | 351 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
> xf86drm.h | 34 ++++++
> 2 files changed, 385 insertions(+)
>
> diff --git a/xf86drm.c b/xf86drm.c
> index 5e02969..237663b 100644
> --- a/xf86drm.c
> +++ b/xf86drm.c
> @@ -55,6 +55,7 @@
> #ifdef HAVE_SYS_MKDEV_H
> # include <sys/mkdev.h> /* defines major(), minor(), and makedev() on Solaris */
> #endif
> +#include <math.h>
>
> /* Not all systems have MAP_FAILED defined */
> #ifndef MAP_FAILED
> @@ -2829,3 +2830,353 @@ char *drmGetRenderDeviceNameFromFd(int fd)
> {
> return drmGetMinorNameForFD(fd, DRM_NODE_RENDER);
> }
> +
> +#ifdef __linux__
> +static int drmParseSubsystemType(const char *str)
> +{
> + char link[PATH_MAX + 1] = "";
> + char *name;
> +
> + if (readlink(str, link, PATH_MAX) < 0)
> + return -EINVAL;
> +
> + name = strrchr(link, '/');
> + if (!name)
> + return -EINVAL;
> +
> + name++;
> +
> + if (strncmp(name, "pci", 3) == 0)
> + return DRM_BUS_PCI;
> +
> + return -EINVAL;
> +}
> +
> +static int drmParsePciBusInfo(const char *str, drmPciBusInfoPtr info)
> +{
> + int domain, bus, dev, func;
> + char *value;
> +
> + if (str == NULL)
> + return -EINVAL;
> +
> + value = strstr(str, "PCI_SLOT_NAME=");
> + if (value == NULL)
> + return -EINVAL;
> +
> + value += strlen("PCI_SLOT_NAME=");
> +
> + if (sscanf(value, "%04x:%02x:%02x.%1u",
> + &domain, &bus, &dev, &func) != 4)
> + return -EINVAL;
> +
> + info->domain = domain;
> + info->bus = bus;
> + info->dev = dev;
> + info->func = func;
> +
> + return 0;
> +}
> +
> +static int drmSameDevice(drmDevicePtr a, drmDevicePtr b)
> +{
> + if (a->bustype != b->bustype)
> + return 0;
> +
> + switch (a->bustype) {
> + case DRM_BUS_PCI:
> + if (memcmp(a->businfo.pci, b->businfo.pci, sizeof(drmPciBusInfo)) == 0)
> + return 1;
> + default:
> + break;
> + }
> +
> + return 0;
> +}
> +
> +static int drmGetNodeType(const char *name)
> +{
> + if (strncmp(name, DRM_PRIMARY_MINOR_NAME,
> + sizeof(DRM_PRIMARY_MINOR_NAME) - 1) == 0)
> + return DRM_NODE_PRIMARY;
> +
> + if (strncmp(name, DRM_CONTROL_MINOR_NAME,
> + sizeof(DRM_CONTROL_MINOR_NAME ) - 1) == 0)
> + return DRM_NODE_CONTROL;
> +
> + if (strncmp(name, DRM_RENDER_MINOR_NAME,
> + sizeof(DRM_RENDER_MINOR_NAME) - 1) == 0)
> + return DRM_NODE_RENDER;
> +
> + return -EINVAL;
> +}
> +
> +static int drmParsePciDeviceInfo(const char *config,
> + drmPciDeviceInfoPtr device)
> +{
> + if (config == NULL)
> + return -EINVAL;
> +
> + device->vendor_id = config[0] | (config[1] << 8);
> + device->device_id = config[2] | (config[3] << 8);
> + device->revision_id = config[8];
> + device->subvendor_id = config[44] | (config[45] << 8);
> + device->subdevice_id = config[46] | (config[47] << 8);
Why not reuse libpciaccess?
-Daniel
> +
> + return 0;
> +}
> +
> +static void drmFreeDevice(drmDevicePtr device)
> +{
> + int i;
> +
> + if (device == NULL)
> + return;
> +
> + if (device->nodes != NULL)
> + for (i = 0; i < DRM_NODE_MAX; i++)
> + free(device->nodes[i]);
> +
> + free(device->nodes);
> + free(device->businfo.pci);
> + free(device->deviceinfo.pci);
> +}
> +
> +void drmFreeDevices(drmDevicePtr devices[], int count)
> +{
> + int i;
> +
> + if (devices == NULL)
> + return;
> +
> + for (i = 0; i < count; i++) {
> + drmFreeDevice(devices[i]);
> + free(devices[i]);
> + devices[i] = NULL;
> + }
> +}
> +
> +/**
> + * Get drm devices on the system
> + *
> + * \param devices the array of devices with drmDevicePtr elements
> + * can be NULL to get the device number first
> + * \param max_devices the maximum number of devices for the array
> + *
> + * \return on error - negative error code,
> + * if devices is NULL - total number of devices available on the system,
> + * alternatively the number of devices stored in devices[], which is
> + * capped by the max_devices.
> + */
> +int drmGetDevices(drmDevicePtr devices[], int max_devices)
> +{
> + drmDevicePtr devs = NULL;
> + drmPciBusInfoPtr pcibus = NULL;
> + drmPciDeviceInfoPtr pcidevice = NULL;
> + DIR *sysdir = NULL;
> + struct dirent *dent = NULL;
> + struct stat sbuf = {0};
> + char node[PATH_MAX + 1] = "";
> + char path[PATH_MAX + 1] = "";
> + char data[128] = "";
> + char config[64] = "";
> + int node_type, subsystem_type;
> + int maj, min;
> + int fd;
> + int ret, i = 0, j, node_count, device_count = 0;
> + int max_count = 16;
> + int *duplicated = NULL;
> +
> + devs = calloc(max_count, sizeof(*devs));
> + if (devs == NULL)
> + return -ENOMEM;
> +
> + sysdir = opendir(DRM_DIR_NAME);
> + if (!sysdir) {
> + ret = -errno;
> + goto free_locals;
> + }
> +
> + while ((dent = readdir(sysdir))) {
> + node_type = drmGetNodeType(dent->d_name);
> + if (node_type < 0)
> + continue;
> +
> + snprintf(node, PATH_MAX, "%s/%s", DRM_DIR_NAME, dent->d_name);
> + if (stat(node, &sbuf))
> + continue;
> +
> + maj = major(sbuf.st_rdev);
> + min = minor(sbuf.st_rdev);
> +
> + if (maj != DRM_MAJOR || !S_ISCHR(sbuf.st_mode))
> + continue;
> +
> + snprintf(path, PATH_MAX, "/sys/dev/char/%d:%d/device/subsystem",
> + maj, min);
> + subsystem_type = drmParseSubsystemType(path);
> +
> + if (subsystem_type < 0)
> + continue;
> +
> + switch (subsystem_type) {
> + case DRM_BUS_PCI:
> + pcibus = calloc(1, sizeof(*pcibus));
> + if (pcibus == NULL) {
> + ret = -ENOMEM;
> + goto free_locals;
> + }
> +
> + snprintf(path, PATH_MAX, "/sys/dev/char/%d:%d/device/uevent",
> + maj, min);
> + fd = open(path, O_RDONLY);
> + if (fd < 0) {
> + ret = -errno;
> + goto free_locals;
> + }
> + ret = read(fd, data, sizeof(data));
> + if (ret < 0) {
> + ret = -errno;
> + close(fd);
> + goto free_locals;
> + }
> +
> + ret = drmParsePciBusInfo(data, pcibus);
> + close(fd);
> + if (ret)
> + goto free_locals;
> +
> + if (i >= max_count) {
> + max_count += 16;
> + devs = realloc(devs, max_count * sizeof(*devs));
> + }
> +
> + devs[i].businfo.pci = pcibus;
> + devs[i].bustype = subsystem_type;
> + devs[i].nodes = calloc(DRM_NODE_MAX, sizeof(char *));
> + if (devs[i].nodes == NULL) {
> + ret = -ENOMEM;
> + goto free_locals;
> + }
> + devs[i].nodes[node_type] = strdup(node);
> + if (devs[i].nodes[node_type] == NULL) {
> + ret = -ENOMEM;
> + goto free_locals;
> + }
> + devs[i].available_nodes = 1 << node_type;
> +
> + if (devices != NULL) {
> + snprintf(path, PATH_MAX, "/sys/class/drm/%s/device/config",
> + dent->d_name);
> + fd = open(path, O_RDONLY);
> + if (fd < 0) {
> + ret = -errno;
> + goto free_locals;
> + }
> + ret = read(fd, config, 64);
> + if (ret < 0) {
> + ret = -errno;
> + close(fd);
> + goto free_locals;
> + }
> +
> + pcidevice = calloc(1, sizeof(*pcidevice));
> + if (pcidevice == NULL) {
> + ret = -ENOMEM;
> + goto free_locals;
> + }
> +
> + ret = drmParsePciDeviceInfo(config, pcidevice);
> + if (ret)
> + goto free_locals;
> +
> + devs[i].deviceinfo.pci = pcidevice;
> + close(fd);
> + }
> + break;
> + default:
> + fprintf(stderr, "The subsystem type is not supported yet\n");
> + break;
> + }
> + i++;
> + }
> +
> + node_count = i;
> +
> + /* merge duplicated devices with same domain/bus/device/func IDs */
> + duplicated = calloc(node_count, sizeof(*duplicated));
> + if (duplicated == NULL) {
> + ret = -ENOMEM;
> + goto free_locals;
> + }
> +
> + for (i = 0; i < node_count; i++) {
> + for (j = i+1; j < node_count; j++) {
> + if (duplicated[i] || duplicated[j])
> + continue;
> + if (drmSameDevice(&devs[i], &devs[j])) {
> + duplicated[j] = 1;
> + devs[i].available_nodes |= devs[j].available_nodes;
> + node_type = log2(devs[j].available_nodes);
> + devs[i].nodes[node_type] = devs[j].nodes[node_type];
> + free(devs[j].nodes);
> + free(devs[j].businfo.pci);
> + free(devs[j].deviceinfo.pci);
> + }
> + }
> + }
> +
> + for (i = 0; i < node_count; i++) {
> + if(duplicated[i] == 0) {
> + if ((devices != NULL) && (device_count < max_devices)) {
> + devices[device_count] = calloc(1, sizeof(drmDevice));
> + if (devices[device_count] == NULL) {
> + ret = -ENOMEM;
> + break;
> + }
> + memcpy(devices[device_count], &devs[i], sizeof(drmDevice));
> + } else
> + drmFreeDevice(&devs[i]);
> + device_count++;
> + }
> + }
> +
> + if (i < node_count) {
> + drmFreeDevices(devices, device_count);
> + for ( ; i < node_count; i++)
> + if(duplicated[i] == 0)
> + drmFreeDevice(&devs[i]);
> + } else
> + ret = device_count;
> +
> + free(duplicated);
> + free(devs);
> + closedir(sysdir);
> + return ret;
> +
> +free_locals:
> + for (j = 0; j < i; j++)
> + drmFreeDevice(&devs[j]);
> + free(pcidevice);
> + free(pcibus);
> + free(devs);
> + closedir(sysdir);
> + return ret;
> +}
> +#else
> +void drmFreeDevices(drmDevicePtr devices[], int count)
> +{
> + (void)devices;
> + (void)count;
> +}
> +
> +int drmGetDevices(drmDevicePtr devices[], int max_devices)
> +{
> + (void)devices;
> + (void)max_devices;
> + return -EINVAL;
> +}
> +
> +#warning "Missing implementation of drmGetDevices/drmFreeDevices"
> +
> +#endif
> diff --git a/xf86drm.h b/xf86drm.h
> index 360e04a..e82ca84 100644
> --- a/xf86drm.h
> +++ b/xf86drm.h
> @@ -563,6 +563,8 @@ extern int drmOpen(const char *name, const char *busid);
> #define DRM_NODE_PRIMARY 0
> #define DRM_NODE_CONTROL 1
> #define DRM_NODE_RENDER 2
> +#define DRM_NODE_MAX 3
> +
> extern int drmOpenWithType(const char *name, const char *busid,
> int type);
>
> @@ -759,6 +761,38 @@ extern int drmPrimeFDToHandle(int fd, int prime_fd, uint32_t *handle);
> extern char *drmGetPrimaryDeviceNameFromFd(int fd);
> extern char *drmGetRenderDeviceNameFromFd(int fd);
>
> +#define DRM_BUS_PCI 0
> +
> +typedef struct _drmPciBusInfo {
> + uint16_t domain;
> + uint8_t bus;
> + uint8_t dev;
> + uint8_t func;
> +} drmPciBusInfo, *drmPciBusInfoPtr;
> +
> +typedef struct _drmPciDeviceInfo {
> + uint16_t vendor_id;
> + uint16_t device_id;
> + uint16_t subvendor_id;
> + uint16_t subdevice_id;
> + uint8_t revision_id;
> +} drmPciDeviceInfo, *drmPciDeviceInfoPtr;
> +
> +typedef struct _drmDevice {
> + char **nodes; /* DRM_NODE_MAX sized array */
> + int available_nodes; /* DRM_NODE_* bitmask */
> + int bustype;
> + union {
> + drmPciBusInfoPtr pci;
> + } businfo;
> + union {
> + drmPciDeviceInfoPtr pci;
> + } deviceinfo;
> +} drmDevice, *drmDevicePtr;
> +
> +extern int drmGetDevices(drmDevicePtr devices[], int max_devices);
> +extern void drmFreeDevices(drmDevicePtr devices[], int count);
> +
> #if defined(__cplusplus)
> }
> #endif
> --
> 1.9.1
>
> _______________________________________________
> dri-devel mailing list
> dri-devel at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/dri-devel
--
Daniel Vetter
Software Engineer, Intel Corporation
http://blog.ffwll.ch
More information about the dri-devel
mailing list