linux-nvgpu/drivers/gpu/nvgpu/common/linux/ioctl_clk_arb.c

/*
 * Copyright (c) 2016-2018, NVIDIA CORPORATION.  All rights reserved.
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <linux/cdev.h>
#include <linux/file.h>
#include <linux/anon_inodes.h>
#include <linux/rculist.h>
#include <linux/llist.h>
#include <linux/uaccess.h>
#include <linux/poll.h>
#ifdef CONFIG_DEBUG_FS
#include <linux/debugfs.h>
#endif
#include <uapi/linux/nvgpu.h>

#include <nvgpu/bitops.h>
#include <nvgpu/lock.h>
#include <nvgpu/kmem.h>
#include <nvgpu/atomic.h>
#include <nvgpu/bug.h>
#include <nvgpu/kref.h>
#include <nvgpu/log.h>
#include <nvgpu/barrier.h>
#include <nvgpu/cond.h>
#include <nvgpu/clk_arb.h>

#include "gk20a/gk20a.h"
#include "clk/clk.h"
#include "clk_arb_linux.h"
#include "pstate/pstate.h"
#include "lpwr/lpwr.h"
#include "volt/volt.h"

#ifdef CONFIG_DEBUG_FS
#include "common/linux/os_linux.h"
#endif

static int nvgpu_clk_arb_release_completion_dev(struct inode *inode,
		struct file *filp)
{
	struct nvgpu_clk_dev *dev = filp->private_data;
	struct nvgpu_clk_session *session = dev->session;


	gk20a_dbg_fn("");

	nvgpu_ref_put(&session->refcount, nvgpu_clk_arb_free_session);
	nvgpu_ref_put(&dev->refcount, nvgpu_clk_arb_free_fd);
	return 0;
}

static unsigned int nvgpu_clk_arb_poll_dev(struct file *filp, poll_table *wait)
{
	struct nvgpu_clk_dev *dev = filp->private_data;

	gk20a_dbg_fn("");

	poll_wait(filp, &dev->readout_wq.wq, wait);
	return nvgpu_atomic_xchg(&dev->poll_mask, 0);
}

static int nvgpu_clk_arb_release_event_dev(struct inode *inode,
		struct file *filp)
{
	struct nvgpu_clk_dev *dev = filp->private_data;
	struct nvgpu_clk_session *session = dev->session;
	struct nvgpu_clk_arb *arb;

	arb = session->g->clk_arb;

	gk20a_dbg_fn("");

	if (arb) {
		nvgpu_spinlock_acquire(&arb->users_lock);
		list_del_rcu(&dev->link);
		nvgpu_spinlock_release(&arb->users_lock);
		nvgpu_clk_notification_queue_free(arb->g, &dev->queue);
	}

	synchronize_rcu();
	nvgpu_ref_put(&session->refcount, nvgpu_clk_arb_free_session);
	nvgpu_ref_put(&dev->refcount, nvgpu_clk_arb_free_fd);

	return 0;
}

static inline u32 __pending_event(struct nvgpu_clk_dev *dev,
		struct nvgpu_gpu_event_info *info) {

	u32 tail, head;
	u32 events = 0;
	struct nvgpu_clk_notification *p_notif;

	tail = nvgpu_atomic_read(&dev->queue.tail);
	head = nvgpu_atomic_read(&dev->queue.head);

	head = (tail - head) < dev->queue.size ? head : tail - dev->queue.size;

	if (_WRAPGTEQ(tail, head) && info) {
		head++;
		p_notif = &dev->queue.notifications[head % dev->queue.size];
		events |= p_notif->notification;
		info->event_id = ffs(events) - 1;
		info->timestamp = p_notif->timestamp;
		nvgpu_atomic_set(&dev->queue.head, head);
	}

	return events;
}

static ssize_t nvgpu_clk_arb_read_event_dev(struct file *filp, char __user *buf,
					size_t size, loff_t *off)
{
	struct nvgpu_clk_dev *dev = filp->private_data;
	struct nvgpu_gpu_event_info info;
	ssize_t err;

	gk20a_dbg_fn("filp=%p, buf=%p, size=%zu", filp, buf, size);

	if ((size - *off) < sizeof(info))
		return 0;

	memset(&info, 0, sizeof(info));
	/* Get the oldest event from the queue */
	while (!__pending_event(dev, &info)) {
		if (filp->f_flags & O_NONBLOCK)
			return -EAGAIN;
		err = NVGPU_COND_WAIT_INTERRUPTIBLE(&dev->readout_wq,
				__pending_event(dev, &info), 0);
		if (err)
			return err;
		if (info.timestamp)
			break;
	}

	if (copy_to_user(buf + *off, &info, sizeof(info)))
		return -EFAULT;

	return sizeof(info);
}

static int nvgpu_clk_arb_set_event_filter(struct nvgpu_clk_dev *dev,
		struct nvgpu_gpu_set_event_filter_args *args)
{
	u32 mask;

	gk20a_dbg(gpu_dbg_fn, "");

	if (args->flags)
		return -EINVAL;

	if (args->size != 1)
		return -EINVAL;

	if (copy_from_user(&mask, (void __user *) args->buffer,
			args->size * sizeof(u32)))
		return -EFAULT;

	/* update alarm mask */
	nvgpu_atomic_set(&dev->enabled_mask, mask);

	return 0;
}

static long nvgpu_clk_arb_ioctl_event_dev(struct file *filp, unsigned int cmd,
		unsigned long arg)
{
	struct nvgpu_clk_dev *dev = filp->private_data;
	struct gk20a *g = dev->session->g;
	u8 buf[NVGPU_EVENT_IOCTL_MAX_ARG_SIZE];
	int err = 0;

	gk20a_dbg(gpu_dbg_fn, "nr=%d", _IOC_NR(cmd));

	if ((_IOC_TYPE(cmd) != NVGPU_EVENT_IOCTL_MAGIC) || (_IOC_NR(cmd) == 0)
		|| (_IOC_NR(cmd) > NVGPU_EVENT_IOCTL_LAST))
		return -EINVAL;

	BUG_ON(_IOC_SIZE(cmd) > NVGPU_EVENT_IOCTL_MAX_ARG_SIZE);

	memset(buf, 0, sizeof(buf));
	if (_IOC_DIR(cmd) & _IOC_WRITE) {
		if (copy_from_user(buf, (void __user *) arg, _IOC_SIZE(cmd)))
			return -EFAULT;
	}

	switch (cmd) {
	case NVGPU_EVENT_IOCTL_SET_FILTER:
		err = nvgpu_clk_arb_set_event_filter(dev,
				(struct nvgpu_gpu_set_event_filter_args *)buf);
		break;
	default:
		nvgpu_warn(g, "unrecognized event ioctl cmd: 0x%x", cmd);
		err = -ENOTTY;
	}

	if ((err == 0) && (_IOC_DIR(cmd) & _IOC_READ))
		err = copy_to_user((void __user *) arg, buf, _IOC_SIZE(cmd));

	return err;
}

static const struct file_operations completion_dev_ops = {
	.owner = THIS_MODULE,
	.release = nvgpu_clk_arb_release_completion_dev,
	.poll = nvgpu_clk_arb_poll_dev,
};

static const struct file_operations event_dev_ops = {
	.owner = THIS_MODULE,
	.release = nvgpu_clk_arb_release_event_dev,
	.poll = nvgpu_clk_arb_poll_dev,
	.read = nvgpu_clk_arb_read_event_dev,
#ifdef CONFIG_COMPAT
	.compat_ioctl = nvgpu_clk_arb_ioctl_event_dev,
#endif
	.unlocked_ioctl = nvgpu_clk_arb_ioctl_event_dev,
};

static int nvgpu_clk_arb_install_fd(struct gk20a *g,
		struct nvgpu_clk_session *session,
		const struct file_operations *fops,
		struct nvgpu_clk_dev **_dev)
{
	struct file *file;
	int fd;
	int err;
	int status;
	char name[64];
	struct nvgpu_clk_dev *dev;

	gk20a_dbg_fn("");

	dev = nvgpu_kzalloc(g, sizeof(*dev));
	if (!dev)
		return -ENOMEM;

	status = nvgpu_clk_notification_queue_alloc(g, &dev->queue,
		DEFAULT_EVENT_NUMBER);
	if (status < 0)  {
		err = status;
		goto fail;
	}

	fd = get_unused_fd_flags(O_RDWR);
	if (fd < 0) {
		err = fd;
		goto fail;
	}

	snprintf(name, sizeof(name), "%s-clk-fd%d", g->name, fd);
	file = anon_inode_getfile(name, fops, dev, O_RDWR);
	if (IS_ERR(file)) {
		err = PTR_ERR(file);
		goto fail_fd;
	}

	fd_install(fd, file);

	nvgpu_cond_init(&dev->readout_wq);

	nvgpu_atomic_set(&dev->poll_mask, 0);

	dev->session = session;
	nvgpu_ref_init(&dev->refcount);

	nvgpu_ref_get(&session->refcount);

	*_dev = dev;

	return fd;

fail_fd:
	put_unused_fd(fd);
fail:
	nvgpu_kfree(g, dev);

	return err;
}

int nvgpu_clk_arb_install_event_fd(struct gk20a *g,
	struct nvgpu_clk_session *session, int *event_fd, u32 alarm_mask)
{
	struct nvgpu_clk_arb *arb = g->clk_arb;
	struct nvgpu_clk_dev *dev;
	int fd;

	gk20a_dbg_fn("");

	fd = nvgpu_clk_arb_install_fd(g, session, &event_dev_ops, &dev);
	if (fd < 0)
		return fd;

	/* TODO: alarm mask needs to be set to default value to prevent
	 * failures of legacy tests. This will be removed when sanity is
	 * updated
	 */
	if (alarm_mask)
		nvgpu_atomic_set(&dev->enabled_mask, alarm_mask);
	else
		nvgpu_atomic_set(&dev->enabled_mask, EVENT(VF_UPDATE));

	dev->arb_queue_head = nvgpu_atomic_read(&arb->notification_queue.head);

	nvgpu_spinlock_acquire(&arb->users_lock);
	list_add_tail_rcu(&dev->link, &arb->users);
	nvgpu_spinlock_release(&arb->users_lock);

	*event_fd = fd;

	return 0;
}

int nvgpu_clk_arb_install_request_fd(struct gk20a *g,
	struct nvgpu_clk_session *session, int *request_fd)
{
	struct nvgpu_clk_dev *dev;
	int fd;

	gk20a_dbg_fn("");

	fd = nvgpu_clk_arb_install_fd(g, session, &completion_dev_ops, &dev);
	if (fd < 0)
		return fd;

	*request_fd = fd;

	return 0;
}

int nvgpu_clk_arb_commit_request_fd(struct gk20a *g,
	struct nvgpu_clk_session *session, int request_fd)
{
	struct nvgpu_clk_arb *arb = g->clk_arb;
	struct nvgpu_clk_dev *dev;
	struct fd fd;
	int err = 0;

	gk20a_dbg_fn("");

	fd  = fdget(request_fd);
	if (!fd.file)
		return -EINVAL;

	if (fd.file->f_op != &completion_dev_ops) {
		err = -EINVAL;
		goto fdput_fd;
	}

	dev = (struct nvgpu_clk_dev *) fd.file->private_data;

	if (!dev || dev->session != session) {
		err = -EINVAL;
		goto fdput_fd;
	}
	nvgpu_ref_get(&dev->refcount);
	llist_add(&dev->node, &session->targets);
	if (arb->update_work_queue)
		queue_work(arb->update_work_queue, &arb->update_fn_work);

fdput_fd:
	fdput(fd);
	return err;
}

int nvgpu_clk_arb_set_session_target_mhz(struct nvgpu_clk_session *session,
		int request_fd, u32 api_domain, u16 target_mhz)
{
	struct nvgpu_clk_dev *dev;
	struct fd fd;
	int err = 0;

	gk20a_dbg_fn("domain=0x%08x target_mhz=%u", api_domain, target_mhz);

	fd = fdget(request_fd);
	if (!fd.file)
		return -EINVAL;

	if (fd.file->f_op != &completion_dev_ops) {
		err = -EINVAL;
		goto fdput_fd;
	}

	dev = fd.file->private_data;
	if (!dev || dev->session != session) {
		err = -EINVAL;
		goto fdput_fd;
	}

	switch (api_domain) {
	case NVGPU_GPU_CLK_DOMAIN_MCLK:
		dev->mclk_target_mhz = target_mhz;
		break;

	case NVGPU_GPU_CLK_DOMAIN_GPCCLK:
		dev->gpc2clk_target_mhz = target_mhz * 2ULL;
		break;

	default:
		err = -EINVAL;
	}

fdput_fd:
	fdput(fd);
	return err;
}

int nvgpu_clk_arb_get_session_target_mhz(struct nvgpu_clk_session *session,
		u32 api_domain, u16 *freq_mhz)
{
	int err = 0;
	struct nvgpu_clk_arb_target *target;

	do {
		target = NV_ACCESS_ONCE(session->target);
		/* no reordering of this pointer */
		nvgpu_smp_rmb();

		switch (api_domain) {
		case NVGPU_GPU_CLK_DOMAIN_MCLK:
			*freq_mhz = target->mclk;
			break;

		case NVGPU_GPU_CLK_DOMAIN_GPCCLK:
			*freq_mhz = target->gpc2clk / 2ULL;
			break;

		default:
			*freq_mhz = 0;
			err = -EINVAL;
		}
	} while (target != NV_ACCESS_ONCE(session->target));
	return err;
}

int nvgpu_clk_arb_get_arbiter_actual_mhz(struct gk20a *g,
		u32 api_domain, u16 *freq_mhz)
{
	struct nvgpu_clk_arb *arb = g->clk_arb;
	int err = 0;
	struct nvgpu_clk_arb_target *actual;

	do {
		actual = NV_ACCESS_ONCE(arb->actual);
		/* no reordering of this pointer */
		nvgpu_smp_rmb();

		switch (api_domain) {
		case NVGPU_GPU_CLK_DOMAIN_MCLK:
			*freq_mhz = actual->mclk;
			break;

		case NVGPU_GPU_CLK_DOMAIN_GPCCLK:
			*freq_mhz = actual->gpc2clk / 2ULL;
			break;

		default:
			*freq_mhz = 0;
			err = -EINVAL;
		}
	} while (actual != NV_ACCESS_ONCE(arb->actual));
	return err;
}

int nvgpu_clk_arb_get_arbiter_effective_mhz(struct gk20a *g,
		u32 api_domain, u16 *freq_mhz)
{
	switch (api_domain) {
	case NVGPU_GPU_CLK_DOMAIN_MCLK:
		*freq_mhz = g->ops.clk.measure_freq(g, CTRL_CLK_DOMAIN_MCLK) /
			1000000ULL;
		return 0;

	case NVGPU_GPU_CLK_DOMAIN_GPCCLK:
		*freq_mhz = g->ops.clk.measure_freq(g,
			CTRL_CLK_DOMAIN_GPC2CLK) / 2000000ULL;
		return 0;

	default:
		return -EINVAL;
	}
}

int nvgpu_clk_arb_get_arbiter_clk_range(struct gk20a *g, u32 api_domain,
		u16 *min_mhz, u16 *max_mhz)
{
	int ret;

	switch (api_domain) {
	case NVGPU_GPU_CLK_DOMAIN_MCLK:
		ret = g->ops.clk_arb.get_arbiter_clk_range(g,
				CTRL_CLK_DOMAIN_MCLK, min_mhz, max_mhz);
		return ret;

	case NVGPU_GPU_CLK_DOMAIN_GPCCLK:
		ret = g->ops.clk_arb.get_arbiter_clk_range(g,
				CTRL_CLK_DOMAIN_GPC2CLK, min_mhz, max_mhz);
		if (!ret) {
			*min_mhz /= 2;
			*max_mhz /= 2;
		}
		return ret;

	default:
		return -EINVAL;
	}
}

u32 nvgpu_clk_arb_get_arbiter_clk_domains(struct gk20a *g)
{
	u32 clk_domains = g->ops.clk_arb.get_arbiter_clk_domains(g);
	u32 api_domains = 0;

	if (clk_domains & CTRL_CLK_DOMAIN_GPC2CLK)
		api_domains |= BIT(NVGPU_GPU_CLK_DOMAIN_GPCCLK);

	if (clk_domains & CTRL_CLK_DOMAIN_MCLK)
		api_domains |= BIT(NVGPU_GPU_CLK_DOMAIN_MCLK);

	return api_domains;
}

bool nvgpu_clk_arb_is_valid_domain(struct gk20a *g, u32 api_domain)
{
	u32 clk_domains = g->ops.clk_arb.get_arbiter_clk_domains(g);

	switch (api_domain) {
	case NVGPU_GPU_CLK_DOMAIN_MCLK:
		return ((clk_domains & CTRL_CLK_DOMAIN_MCLK) != 0);

	case NVGPU_GPU_CLK_DOMAIN_GPCCLK:
		return ((clk_domains & CTRL_CLK_DOMAIN_GPC2CLK) != 0);

	default:
		return false;
	}
}

int nvgpu_clk_arb_get_arbiter_clk_f_points(struct gk20a *g,
	u32 api_domain, u32 *max_points, u16 *fpoints)
{
	int err;
	u32 i;

	switch (api_domain) {
	case NVGPU_GPU_CLK_DOMAIN_GPCCLK:
		err = clk_domain_get_f_points(g, CTRL_CLK_DOMAIN_GPC2CLK,
				max_points, fpoints);
		if (err || !fpoints)
			return err;
		for (i = 0; i < *max_points; i++)
			fpoints[i] /= 2;
		return 0;
	case NVGPU_GPU_CLK_DOMAIN_MCLK:
		return clk_domain_get_f_points(g, CTRL_CLK_DOMAIN_MCLK,
				max_points, fpoints);
	default:
		return -EINVAL;
	}
}

#ifdef CONFIG_DEBUG_FS
static int nvgpu_clk_arb_stats_show(struct seq_file *s, void *unused)
{
	struct gk20a *g = s->private;
	struct nvgpu_clk_arb *arb = g->clk_arb;
	struct nvgpu_clk_arb_debug *debug;

	u64 num;
	s64 tmp, avg, std, max, min;

	debug = NV_ACCESS_ONCE(arb->debug);
	/* Make copy of structure and ensure no reordering */
	nvgpu_smp_rmb();
	if (!debug)
		return -EINVAL;

	std = debug->switch_std;
	avg = debug->switch_avg;
	max = debug->switch_max;
	min = debug->switch_min;
	num = debug->switch_num;

	tmp = std;
	do_div(tmp, num);
	seq_printf(s, "Number of transitions: %lld\n",
		num);
	seq_printf(s, "max / min : %lld / %lld usec\n",
		max, min);
	seq_printf(s, "avg / std : %lld / %ld usec\n",
		avg, int_sqrt(tmp));

	return 0;
}

static int nvgpu_clk_arb_stats_open(struct inode *inode, struct file *file)
{
	return single_open(file, nvgpu_clk_arb_stats_show, inode->i_private);
}

static const struct file_operations nvgpu_clk_arb_stats_fops = {
	.open		= nvgpu_clk_arb_stats_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};


int nvgpu_clk_arb_debugfs_init(struct gk20a *g)
{
	struct nvgpu_os_linux *l = nvgpu_os_linux_from_gk20a(g);
	struct dentry *gpu_root = l->debugfs;
	struct dentry *d;

	gk20a_dbg(gpu_dbg_info, "g=%p", g);

	d = debugfs_create_file(
			"arb_stats",
			S_IRUGO,
			gpu_root,
			g,
			&nvgpu_clk_arb_stats_fops);
	if (!d)
		return -ENOMEM;

	return 0;
}
#endif