/* * Copyright © 2008 Intel Corporation * Copyright © 2016 Collabora Ltd * * Permission is hereby granted, free of charge, to any person obtaining a * copy of this software and associated documentation files (the "Software"), * to deal in the Software without restriction, including without limitation * the rights to use, copy, modify, merge, publish, distribute, sublicense, * and/or sell copies of the Software, and to permit persons to whom the * Software is furnished to do so, subject to the following conditions: * * The above copyright notice and this permission notice (including the next * paragraph) shall be included in all copies or substantial portions of the * Software. * * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS * IN THE SOFTWARE. * * Based on code from the i915 driver. * Original author: Damien Lespiau <damien.lespiau@intel.com> * */ #include <linux/circ_buf.h>#include <linux/ctype.h>#include <linux/debugfs.h>#include <linux/export.h>#include <linux/poll.h>#include <linux/uaccess.h> #include <drm/drm_crtc.h>#include <drm/drm_debugfs_crc.h>#include <drm/drm_drv.h>#include <drm/drm_print.h> #include "drm_internal.h" /** * DOC: CRC ABI * * DRM device drivers can provide to userspace CRC information of each frame as * it reached a given hardware component (a CRC sampling "source"). * * Userspace can control generation of CRCs in a given CRTC by writing to the * file dri/0/crtc-N/crc/control in debugfs, with N being the :ref:`index of * the CRTC<crtc_index>`. Accepted values are source names (which are * driver-specific) and the "auto" keyword, which will let the driver select a * default source of frame CRCs for this CRTC. * * Once frame CRC generation is enabled, userspace can capture them by reading * the dri/0/crtc-N/crc/data file. Each line in that file contains the frame * number in the first field and then a number of unsigned integer fields * containing the CRC data. Fields are separated by a single space and the number * of CRC fields is source-specific. * * Note that though in some cases the CRC is computed in a specified way and on * the frame contents as supplied by userspace (eDP 1.3), in general the CRC * computation is performed in an unspecified way and on frame contents that have * been already processed in also an unspecified way and thus userspace cannot * rely on being able to generate matching CRC values for the frame contents that * it submits. In this general case, the maximum userspace can do is to compare * the reported CRCs of frames that should have the same contents. * * On the driver side the implementation effort is minimal, drivers only need to * implement &drm_crtc_funcs.set_crc_source and &drm_crtc_funcs.verify_crc_source. * The debugfs files are automatically set up if those vfuncs are set. CRC samples * need to be captured in the driver by calling drm_crtc_add_crc_entry(). * Depending on the driver and HW requirements, &drm_crtc_funcs.set_crc_source * may result in a commit (even a full modeset). * * CRC results must be reliable across non-full-modeset atomic commits, so if a * commit via DRM_IOCTL_MODE_ATOMIC would disable or otherwise interfere with * CRC generation, then the driver must mark that commit as a full modeset * (drm_atomic_crtc_needs_modeset() should return true). As a result, to ensure * consistent results, generic userspace must re-setup CRC generation after a * legacy SETCRTC or an atomic commit with DRM_MODE_ATOMIC_ALLOW_MODESET. */ static int crc_control_show(struct seq_file *m, void *data){	struct drm_crtc *crtc = m->private; 	if (crtc->funcs->get_crc_sources) {		size_t count;		const char *const *sources = crtc->funcs->get_crc_sources(crtc,									&count);		size_t values_cnt;		int i; 		if (count == 0 || !sources)			goto out; 		for (i = 0; i < count; i++)			if (!crtc->funcs->verify_crc_source(crtc, sources[i],							    &values_cnt)) {				if (strcmp(sources[i], crtc->crc.source))					seq_printf(m, "%s\n", sources[i]);				else					seq_printf(m, "%s*\n", sources[i]);			}	}	return 0; out:	seq_printf(m, "%s*\n", crtc->crc.source);	return 0;} static int crc_control_open(struct inode *inode, struct file *file){	struct drm_crtc *crtc = inode->i_private; 	return single_open(file, crc_control_show, crtc);} static ssize_t crc_control_write(struct file *file, const char __user *ubuf,				 size_t len, loff_t *offp){	struct seq_file *m = file->private_data;	struct drm_crtc *crtc = m->private;	struct drm_crtc_crc *crc = &crtc->crc;	char *source;	size_t values_cnt;	int ret; 	if (len == 0)		return 0; 	if (len > PAGE_SIZE - 1) {		DRM_DEBUG_KMS("Expected < %lu bytes into crtc crc control\n",			      PAGE_SIZE);		return -E2BIG;	} 	source = memdup_user_nul(ubuf, len);	if (IS_ERR(source))		return PTR_ERR(source); 	if (source[len - 1] == '\n')		source[len - 1] = '\0'; 	ret = crtc->funcs->verify_crc_source(crtc, source, &values_cnt);	if (ret) {		kfree(source);		return ret;	} 	spin_lock_irq(&crc->lock); 	if (crc->opened) {		spin_unlock_irq(&crc->lock);		kfree(source);		return -EBUSY;	} 	kfree(crc->source);	crc->source = source; 	spin_unlock_irq(&crc->lock); 	*offp += len;	return len;} static const struct file_operations drm_crtc_crc_control_fops = {	.owner = THIS_MODULE,	.open = crc_control_open,	.read = seq_read,	.llseek = seq_lseek,	.release = single_release,	.write = crc_control_write}; static int crtc_crc_data_count(struct drm_crtc_crc *crc){	assert_spin_locked(&crc->lock);	return CIRC_CNT(crc->head, crc->tail, DRM_CRC_ENTRIES_NR);} static void crtc_crc_cleanup(struct drm_crtc_crc *crc){	kfree(crc->entries);	crc->overflow = false;	crc->entries = NULL;	crc->head = 0;	crc->tail = 0;	crc->values_cnt = 0;	crc->opened = false;} static int crtc_crc_open(struct inode *inode, struct file *filep){	struct drm_crtc *crtc = inode->i_private;	struct drm_crtc_crc *crc = &crtc->crc;	struct drm_crtc_crc_entry *entries = NULL;	size_t values_cnt;	int ret = 0; 	if (drm_drv_uses_atomic_modeset(crtc->dev)) {		ret = drm_modeset_lock_single_interruptible(&crtc->mutex);		if (ret)			return ret; 		if (!crtc->state->active)			ret = -EIO;		drm_modeset_unlock(&crtc->mutex); 		if (ret)			return ret;	} 	ret = crtc->funcs->verify_crc_source(crtc, crc->source, &values_cnt);	if (ret)		return ret; 	if (WARN_ON(values_cnt > DRM_MAX_CRC_NR))		return -EINVAL; 	if (WARN_ON(values_cnt == 0))		return -EINVAL; 	entries = kzalloc_objs(*entries, DRM_CRC_ENTRIES_NR);	if (!entries)		return -ENOMEM; 	spin_lock_irq(&crc->lock);	if (!crc->opened) {		crc->opened = true;		crc->entries = entries;		crc->values_cnt = values_cnt;	} else {		ret = -EBUSY;	}	spin_unlock_irq(&crc->lock); 	if (ret) {		kfree(entries);		return ret;	} 	ret = crtc->funcs->set_crc_source(crtc, crc->source);	if (ret)		goto err; 	return 0; err:	spin_lock_irq(&crc->lock);	crtc_crc_cleanup(crc);	spin_unlock_irq(&crc->lock);	return ret;} static int crtc_crc_release(struct inode *inode, struct file *filep){	struct drm_crtc *crtc = filep->f_inode->i_private;	struct drm_crtc_crc *crc = &crtc->crc; 	/* terminate the infinite while loop if 'drm_dp_aux_crc_work' running */	spin_lock_irq(&crc->lock);	crc->opened = false;	spin_unlock_irq(&crc->lock); 	crtc->funcs->set_crc_source(crtc, NULL); 	spin_lock_irq(&crc->lock);	crtc_crc_cleanup(crc);	spin_unlock_irq(&crc->lock); 	return 0;} /* * 1 frame field of 10 chars plus a number of CRC fields of 10 chars each, space * separated, with a newline at the end and null-terminated. */#define LINE_LEN(values_cnt)	(10 + 11 * values_cnt + 1 + 1)#define MAX_LINE_LEN		(LINE_LEN(DRM_MAX_CRC_NR)) static ssize_t crtc_crc_read(struct file *filep, char __user *user_buf,			     size_t count, loff_t *pos){	struct drm_crtc *crtc = filep->f_inode->i_private;	struct drm_crtc_crc *crc = &crtc->crc;	struct drm_crtc_crc_entry *entry;	char buf[MAX_LINE_LEN];	int ret, i; 	spin_lock_irq(&crc->lock); 	if (!crc->source) {		spin_unlock_irq(&crc->lock);		return 0;	} 	/* Nothing to read? */	while (crtc_crc_data_count(crc) == 0) {		if (filep->f_flags & O_NONBLOCK) {			spin_unlock_irq(&crc->lock);			return -EAGAIN;		} 		ret = wait_event_interruptible_lock_irq(crc->wq,							crtc_crc_data_count(crc),							crc->lock);		if (ret) {			spin_unlock_irq(&crc->lock);			return ret;		}	} 	/* We know we have an entry to be read */	entry = &crc->entries[crc->tail]; 	if (count < LINE_LEN(crc->values_cnt)) {		spin_unlock_irq(&crc->lock);		return -EINVAL;	} 	BUILD_BUG_ON_NOT_POWER_OF_2(DRM_CRC_ENTRIES_NR);	crc->tail = (crc->tail + 1) & (DRM_CRC_ENTRIES_NR - 1); 	spin_unlock_irq(&crc->lock); 	if (entry->has_frame_counter)		sprintf(buf, "0x%08x", entry->frame);	else		sprintf(buf, "XXXXXXXXXX"); 	for (i = 0; i < crc->values_cnt; i++)		sprintf(buf + 10 + i * 11, " 0x%08x", entry->crcs[i]);	sprintf(buf + 10 + crc->values_cnt * 11, "\n"); 	if (copy_to_user(user_buf, buf, LINE_LEN(crc->values_cnt)))		return -EFAULT; 	return LINE_LEN(crc->values_cnt);} static __poll_t crtc_crc_poll(struct file *file, poll_table *wait){	struct drm_crtc *crtc = file->f_inode->i_private;	struct drm_crtc_crc *crc = &crtc->crc;	__poll_t ret = 0; 	poll_wait(file, &crc->wq, wait); 	spin_lock_irq(&crc->lock);	if (crc->source && crtc_crc_data_count(crc))		ret |= EPOLLIN | EPOLLRDNORM;	spin_unlock_irq(&crc->lock); 	return ret;} static const struct file_operations drm_crtc_crc_data_fops = {	.owner = THIS_MODULE,	.open = crtc_crc_open,	.read = crtc_crc_read,	.poll = crtc_crc_poll,	.release = crtc_crc_release,}; void drm_debugfs_crtc_crc_add(struct drm_crtc *crtc){	struct dentry *crc_ent; 	if (!crtc->funcs->set_crc_source || !crtc->funcs->verify_crc_source)		return; 	crc_ent = debugfs_create_dir("crc", crtc->debugfs_entry); 	debugfs_create_file("control", S_IRUGO | S_IWUSR, crc_ent, crtc,			    &drm_crtc_crc_control_fops);	debugfs_create_file("data", S_IRUGO, crc_ent, crtc,			    &drm_crtc_crc_data_fops);} /** * drm_crtc_add_crc_entry - Add entry with CRC information for a frame * @crtc: CRTC to which the frame belongs * @has_frame: whether this entry has a frame number to go with * @frame: number of the frame these CRCs are about * @crcs: array of CRC values, with length matching #drm_crtc_crc.values_cnt * * For each frame, the driver polls the source of CRCs for new data and calls * this function to add them to the buffer from where userspace reads. */int drm_crtc_add_crc_entry(struct drm_crtc *crtc, bool has_frame,			   uint32_t frame, uint32_t *crcs){	struct drm_crtc_crc *crc = &crtc->crc;	struct drm_crtc_crc_entry *entry;	int head, tail;	unsigned long flags; 	spin_lock_irqsave(&crc->lock, flags); 	/* Caller may not have noticed yet that userspace has stopped reading */	if (!crc->entries) {		spin_unlock_irqrestore(&crc->lock, flags);		return -EINVAL;	} 	head = crc->head;	tail = crc->tail; 	if (CIRC_SPACE(head, tail, DRM_CRC_ENTRIES_NR) < 1) {		bool was_overflow = crc->overflow; 		crc->overflow = true;		spin_unlock_irqrestore(&crc->lock, flags); 		if (!was_overflow)			DRM_ERROR("Overflow of CRC buffer, userspace reads too slow.\n"); 		return -ENOBUFS;	} 	entry = &crc->entries[head];	entry->frame = frame;	entry->has_frame_counter = has_frame;	memcpy(&entry->crcs, crcs, sizeof(*crcs) * crc->values_cnt); 	head = (head + 1) & (DRM_CRC_ENTRIES_NR - 1);	crc->head = head; 	spin_unlock_irqrestore(&crc->lock, flags); 	wake_up_interruptible(&crc->wq); 	return 0;}EXPORT_SYMBOL_GPL(drm_crtc_add_crc_entry);