| /* |
| * 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/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 index of the CRTC. |
| * 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 = kcalloc(DRM_CRC_ENTRIES_NR, sizeof(*entries), GFP_KERNEL); |
| 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; |
| |
| 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 unsigned int 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; |
| unsigned ret; |
| |
| poll_wait(file, &crc->wq, wait); |
| |
| spin_lock_irq(&crc->lock); |
| if (crc->source && crtc_crc_data_count(crc)) |
| ret = POLLIN | POLLRDNORM; |
| else |
| ret = 0; |
| 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, 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); |