xref: /dpdk/lib/gpudev/gpudev.c (revision a9af048abaacc2a0cbdc284e033390f13a0c2525)

/* SPDX-License-Identifier: BSD-3-Clause
 * Copyright (c) 2021 NVIDIA Corporation & Affiliates
 */

#include <rte_eal.h>
#include <rte_tailq.h>
#include <rte_rwlock.h>
#include <rte_string_fns.h>
#include <rte_memzone.h>
#include <rte_errno.h>
#include <rte_log.h>

#include "rte_gpudev.h"
#include "gpudev_driver.h"

/* Logging */
RTE_LOG_REGISTER_DEFAULT(gpu_logtype, NOTICE);
#define GPU_LOG(level, ...) \
	rte_log(RTE_LOG_ ## level, gpu_logtype, RTE_FMT("gpu: " \
		RTE_FMT_HEAD(__VA_ARGS__, ) "\n", RTE_FMT_TAIL(__VA_ARGS__, )))

/* Set any driver error as EPERM */
#define GPU_DRV_RET(function) \
	((function != 0) ? -(rte_errno = EPERM) : (rte_errno = 0))

/* Array of devices */
static struct rte_gpu *gpus;
/* Number of currently valid devices */
static int16_t gpu_max;
/* Number of currently valid devices */
static int16_t gpu_count;

/* Shared memory between processes. */
static const char *GPU_MEMZONE = "rte_gpu_shared";
static struct {
	__extension__ struct rte_gpu_mpshared gpus[0];
} *gpu_shared_mem;

/* Event callback object */
struct rte_gpu_callback {
	TAILQ_ENTRY(rte_gpu_callback) next;
	rte_gpu_callback_t *function;
	void *user_data;
	enum rte_gpu_event event;
};
static rte_rwlock_t gpu_callback_lock = RTE_RWLOCK_INITIALIZER;
static void gpu_free_callbacks(struct rte_gpu *dev);

int
rte_gpu_init(size_t dev_max)
{
	if (dev_max == 0 || dev_max > INT16_MAX) {
		GPU_LOG(ERR, "invalid array size");
		rte_errno = EINVAL;
		return -rte_errno;
	}

	/* No lock, it must be called before or during first probing. */
	if (gpus != NULL) {
		GPU_LOG(ERR, "already initialized");
		rte_errno = EBUSY;
		return -rte_errno;
	}

	gpus = calloc(dev_max, sizeof(struct rte_gpu));
	if (gpus == NULL) {
		GPU_LOG(ERR, "cannot initialize library");
		rte_errno = ENOMEM;
		return -rte_errno;
	}

	gpu_max = dev_max;
	return 0;
}

uint16_t
rte_gpu_count_avail(void)
{
	return gpu_count;
}

bool
rte_gpu_is_valid(int16_t dev_id)
{
	if (dev_id >= 0 && dev_id < gpu_max &&
		gpus[dev_id].process_state == RTE_GPU_STATE_INITIALIZED)
		return true;
	return false;
}

static bool
gpu_match_parent(int16_t dev_id, int16_t parent)
{
	if (parent == RTE_GPU_ID_ANY)
		return true;
	return gpus[dev_id].mpshared->info.parent == parent;
}

int16_t
rte_gpu_find_next(int16_t dev_id, int16_t parent)
{
	if (dev_id < 0)
		dev_id = 0;
	while (dev_id < gpu_max &&
			(gpus[dev_id].process_state == RTE_GPU_STATE_UNUSED ||
			!gpu_match_parent(dev_id, parent)))
		dev_id++;

	if (dev_id >= gpu_max)
		return RTE_GPU_ID_NONE;
	return dev_id;
}

static int16_t
gpu_find_free_id(void)
{
	int16_t dev_id;

	for (dev_id = 0; dev_id < gpu_max; dev_id++) {
		if (gpus[dev_id].process_state == RTE_GPU_STATE_UNUSED)
			return dev_id;
	}
	return RTE_GPU_ID_NONE;
}

static struct rte_gpu *
gpu_get_by_id(int16_t dev_id)
{
	if (!rte_gpu_is_valid(dev_id))
		return NULL;
	return &gpus[dev_id];
}

struct rte_gpu *
rte_gpu_get_by_name(const char *name)
{
	int16_t dev_id;
	struct rte_gpu *dev;

	if (name == NULL) {
		rte_errno = EINVAL;
		return NULL;
	}

	RTE_GPU_FOREACH(dev_id) {
		dev = &gpus[dev_id];
		if (strncmp(name, dev->mpshared->name, RTE_DEV_NAME_MAX_LEN) == 0)
			return dev;
	}
	return NULL;
}

static int
gpu_shared_mem_init(void)
{
	const struct rte_memzone *memzone;

	if (rte_eal_process_type() == RTE_PROC_PRIMARY) {
		memzone = rte_memzone_reserve(GPU_MEMZONE,
				sizeof(*gpu_shared_mem) +
				sizeof(*gpu_shared_mem->gpus) * gpu_max,
				SOCKET_ID_ANY, 0);
	} else {
		memzone = rte_memzone_lookup(GPU_MEMZONE);
	}
	if (memzone == NULL) {
		GPU_LOG(ERR, "cannot initialize shared memory");
		rte_errno = ENOMEM;
		return -rte_errno;
	}

	gpu_shared_mem = memzone->addr;
	return 0;
}

struct rte_gpu *
rte_gpu_allocate(const char *name)
{
	int16_t dev_id;
	struct rte_gpu *dev;

	if (rte_eal_process_type() != RTE_PROC_PRIMARY) {
		GPU_LOG(ERR, "only primary process can allocate device");
		rte_errno = EPERM;
		return NULL;
	}
	if (name == NULL) {
		GPU_LOG(ERR, "allocate device without a name");
		rte_errno = EINVAL;
		return NULL;
	}

	/* implicit initialization of library before adding first device */
	if (gpus == NULL && rte_gpu_init(RTE_GPU_DEFAULT_MAX) < 0)
		return NULL;

	/* initialize shared memory before adding first device */
	if (gpu_shared_mem == NULL && gpu_shared_mem_init() < 0)
		return NULL;

	if (rte_gpu_get_by_name(name) != NULL) {
		GPU_LOG(ERR, "device with name %s already exists", name);
		rte_errno = EEXIST;
		return NULL;
	}
	dev_id = gpu_find_free_id();
	if (dev_id == RTE_GPU_ID_NONE) {
		GPU_LOG(ERR, "reached maximum number of devices");
		rte_errno = ENOENT;
		return NULL;
	}

	dev = &gpus[dev_id];
	memset(dev, 0, sizeof(*dev));

	dev->mpshared = &gpu_shared_mem->gpus[dev_id];
	memset(dev->mpshared, 0, sizeof(*dev->mpshared));

	if (rte_strscpy(dev->mpshared->name, name, RTE_DEV_NAME_MAX_LEN) < 0) {
		GPU_LOG(ERR, "device name too long: %s", name);
		rte_errno = ENAMETOOLONG;
		return NULL;
	}
	dev->mpshared->info.name = dev->mpshared->name;
	dev->mpshared->info.dev_id = dev_id;
	dev->mpshared->info.numa_node = -1;
	dev->mpshared->info.parent = RTE_GPU_ID_NONE;
	TAILQ_INIT(&dev->callbacks);
	__atomic_fetch_add(&dev->mpshared->process_refcnt, 1, __ATOMIC_RELAXED);

	gpu_count++;
	GPU_LOG(DEBUG, "new device %s (id %d) of total %d",
			name, dev_id, gpu_count);
	return dev;
}

struct rte_gpu *
rte_gpu_attach(const char *name)
{
	int16_t dev_id;
	struct rte_gpu *dev;
	struct rte_gpu_mpshared *shared_dev;

	if (rte_eal_process_type() != RTE_PROC_SECONDARY) {
		GPU_LOG(ERR, "only secondary process can attach device");
		rte_errno = EPERM;
		return NULL;
	}
	if (name == NULL) {
		GPU_LOG(ERR, "attach device without a name");
		rte_errno = EINVAL;
		return NULL;
	}

	/* implicit initialization of library before adding first device */
	if (gpus == NULL && rte_gpu_init(RTE_GPU_DEFAULT_MAX) < 0)
		return NULL;

	/* initialize shared memory before adding first device */
	if (gpu_shared_mem == NULL && gpu_shared_mem_init() < 0)
		return NULL;

	for (dev_id = 0; dev_id < gpu_max; dev_id++) {
		shared_dev = &gpu_shared_mem->gpus[dev_id];
		if (strncmp(name, shared_dev->name, RTE_DEV_NAME_MAX_LEN) == 0)
			break;
	}
	if (dev_id >= gpu_max) {
		GPU_LOG(ERR, "device with name %s not found", name);
		rte_errno = ENOENT;
		return NULL;
	}
	dev = &gpus[dev_id];
	memset(dev, 0, sizeof(*dev));

	TAILQ_INIT(&dev->callbacks);
	dev->mpshared = shared_dev;
	__atomic_fetch_add(&dev->mpshared->process_refcnt, 1, __ATOMIC_RELAXED);

	gpu_count++;
	GPU_LOG(DEBUG, "attached device %s (id %d) of total %d",
			name, dev_id, gpu_count);
	return dev;
}

int16_t
rte_gpu_add_child(const char *name, int16_t parent, uint64_t child_context)
{
	struct rte_gpu *dev;

	if (!rte_gpu_is_valid(parent)) {
		GPU_LOG(ERR, "add child to invalid parent ID %d", parent);
		rte_errno = ENODEV;
		return -rte_errno;
	}

	dev = rte_gpu_allocate(name);
	if (dev == NULL)
		return -rte_errno;

	dev->mpshared->info.parent = parent;
	dev->mpshared->info.context = child_context;

	rte_gpu_complete_new(dev);
	return dev->mpshared->info.dev_id;
}

void
rte_gpu_complete_new(struct rte_gpu *dev)
{
	if (dev == NULL)
		return;

	dev->process_state = RTE_GPU_STATE_INITIALIZED;
	rte_gpu_notify(dev, RTE_GPU_EVENT_NEW);
}

int
rte_gpu_release(struct rte_gpu *dev)
{
	int16_t dev_id, child;

	if (dev == NULL) {
		rte_errno = ENODEV;
		return -rte_errno;
	}
	dev_id = dev->mpshared->info.dev_id;
	RTE_GPU_FOREACH_CHILD(child, dev_id) {
		GPU_LOG(ERR, "cannot release device %d with child %d",
				dev_id, child);
		rte_errno = EBUSY;
		return -rte_errno;
	}

	GPU_LOG(DEBUG, "free device %s (id %d)",
			dev->mpshared->info.name, dev->mpshared->info.dev_id);
	rte_gpu_notify(dev, RTE_GPU_EVENT_DEL);

	gpu_free_callbacks(dev);
	dev->process_state = RTE_GPU_STATE_UNUSED;
	__atomic_fetch_sub(&dev->mpshared->process_refcnt, 1, __ATOMIC_RELAXED);
	gpu_count--;

	return 0;
}

int
rte_gpu_close(int16_t dev_id)
{
	int firsterr, binerr;
	int *lasterr = &firsterr;
	struct rte_gpu *dev;

	dev = gpu_get_by_id(dev_id);
	if (dev == NULL) {
		GPU_LOG(ERR, "close invalid device ID %d", dev_id);
		rte_errno = ENODEV;
		return -rte_errno;
	}

	if (dev->ops.dev_close != NULL) {
		*lasterr = GPU_DRV_RET(dev->ops.dev_close(dev));
		if (*lasterr != 0)
			lasterr = &binerr;
	}

	*lasterr = rte_gpu_release(dev);

	rte_errno = -firsterr;
	return firsterr;
}

int
rte_gpu_callback_register(int16_t dev_id, enum rte_gpu_event event,
		rte_gpu_callback_t *function, void *user_data)
{
	int16_t next_dev, last_dev;
	struct rte_gpu_callback_list *callbacks;
	struct rte_gpu_callback *callback;

	if (!rte_gpu_is_valid(dev_id) && dev_id != RTE_GPU_ID_ANY) {
		GPU_LOG(ERR, "register callback of invalid ID %d", dev_id);
		rte_errno = ENODEV;
		return -rte_errno;
	}
	if (function == NULL) {
		GPU_LOG(ERR, "cannot register callback without function");
		rte_errno = EINVAL;
		return -rte_errno;
	}

	if (dev_id == RTE_GPU_ID_ANY) {
		next_dev = 0;
		last_dev = gpu_max - 1;
	} else {
		next_dev = last_dev = dev_id;
	}

	rte_rwlock_write_lock(&gpu_callback_lock);
	do {
		callbacks = &gpus[next_dev].callbacks;

		/* check if not already registered */
		TAILQ_FOREACH(callback, callbacks, next) {
			if (callback->event == event &&
					callback->function == function &&
					callback->user_data == user_data) {
				GPU_LOG(INFO, "callback already registered");
				return 0;
			}
		}

		callback = malloc(sizeof(*callback));
		if (callback == NULL) {
			GPU_LOG(ERR, "cannot allocate callback");
			return -ENOMEM;
		}
		callback->function = function;
		callback->user_data = user_data;
		callback->event = event;
		TAILQ_INSERT_TAIL(callbacks, callback, next);

	} while (++next_dev <= last_dev);
	rte_rwlock_write_unlock(&gpu_callback_lock);

	return 0;
}

int
rte_gpu_callback_unregister(int16_t dev_id, enum rte_gpu_event event,
		rte_gpu_callback_t *function, void *user_data)
{
	int16_t next_dev, last_dev;
	struct rte_gpu_callback_list *callbacks;
	struct rte_gpu_callback *callback, *nextcb;

	if (!rte_gpu_is_valid(dev_id) && dev_id != RTE_GPU_ID_ANY) {
		GPU_LOG(ERR, "unregister callback of invalid ID %d", dev_id);
		rte_errno = ENODEV;
		return -rte_errno;
	}
	if (function == NULL) {
		GPU_LOG(ERR, "cannot unregister callback without function");
		rte_errno = EINVAL;
		return -rte_errno;
	}

	if (dev_id == RTE_GPU_ID_ANY) {
		next_dev = 0;
		last_dev = gpu_max - 1;
	} else {
		next_dev = last_dev = dev_id;
	}

	rte_rwlock_write_lock(&gpu_callback_lock);
	do {
		callbacks = &gpus[next_dev].callbacks;
		RTE_TAILQ_FOREACH_SAFE(callback, callbacks, next, nextcb) {
			if (callback->event != event ||
					callback->function != function ||
					(callback->user_data != user_data &&
					user_data != (void *)-1))
				continue;
			TAILQ_REMOVE(callbacks, callback, next);
			free(callback);
		}
	} while (++next_dev <= last_dev);
	rte_rwlock_write_unlock(&gpu_callback_lock);

	return 0;
}

static void
gpu_free_callbacks(struct rte_gpu *dev)
{
	struct rte_gpu_callback_list *callbacks;
	struct rte_gpu_callback *callback, *nextcb;

	callbacks = &dev->callbacks;
	rte_rwlock_write_lock(&gpu_callback_lock);
	RTE_TAILQ_FOREACH_SAFE(callback, callbacks, next, nextcb) {
		TAILQ_REMOVE(callbacks, callback, next);
		free(callback);
	}
	rte_rwlock_write_unlock(&gpu_callback_lock);
}

void
rte_gpu_notify(struct rte_gpu *dev, enum rte_gpu_event event)
{
	int16_t dev_id;
	struct rte_gpu_callback *callback;

	dev_id = dev->mpshared->info.dev_id;
	rte_rwlock_read_lock(&gpu_callback_lock);
	TAILQ_FOREACH(callback, &dev->callbacks, next) {
		if (callback->event != event || callback->function == NULL)
			continue;
		callback->function(dev_id, event, callback->user_data);
	}
	rte_rwlock_read_unlock(&gpu_callback_lock);
}

int
rte_gpu_info_get(int16_t dev_id, struct rte_gpu_info *info)
{
	struct rte_gpu *dev;

	dev = gpu_get_by_id(dev_id);
	if (dev == NULL) {
		GPU_LOG(ERR, "query invalid device ID %d", dev_id);
		rte_errno = ENODEV;
		return -rte_errno;
	}
	if (info == NULL) {
		GPU_LOG(ERR, "query without storage");
		rte_errno = EINVAL;
		return -rte_errno;
	}

	if (dev->ops.dev_info_get == NULL) {
		*info = dev->mpshared->info;
		return 0;
	}
	return GPU_DRV_RET(dev->ops.dev_info_get(dev, info));
}