--- /dev/null
+/*
+ * 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 <drm/drmP.h>
+
+/**
+ * DOC: CRC ABI
+ *
+ * DRM device drivers can provide to userspace CRC information of each frame as
+ * it reached a given hardware component (a "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.
+ */
+
+static int crc_control_show(struct seq_file *m, void *data)
+{
+ struct drm_crtc *crtc = m->private;
+
+ 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;
+
+ 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] == '\n')
+ source[len] = '\0';
+
+ 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;
+}
+
+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_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;
+
+ if (crc->opened)
+ return -EBUSY;
+
+ ret = crtc->funcs->set_crc_source(crtc, crc->source, &values_cnt);
+ if (ret)
+ return ret;
+
+ if (WARN_ON(values_cnt > DRM_MAX_CRC_NR)) {
+ ret = -EINVAL;
+ goto err_disable;
+ }
+
+ if (WARN_ON(values_cnt == 0)) {
+ ret = -EINVAL;
+ goto err_disable;
+ }
+
+ entries = kcalloc(DRM_CRC_ENTRIES_NR, sizeof(*entries), GFP_KERNEL);
+ if (!entries) {
+ ret = -ENOMEM;
+ goto err_disable;
+ }
+
+ spin_lock_irq(&crc->lock);
+ crc->entries = entries;
+ crc->values_cnt = values_cnt;
+ crc->opened = true;
+ spin_unlock_irq(&crc->lock);
+
+ return 0;
+
+err_disable:
+ crtc->funcs->set_crc_source(crtc, NULL, &values_cnt);
+ 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;
+ size_t values_cnt;
+
+ spin_lock_irq(&crc->lock);
+ kfree(crc->entries);
+ crc->entries = NULL;
+ crc->head = 0;
+ crc->tail = 0;
+ crc->values_cnt = 0;
+ crc->opened = false;
+ spin_unlock_irq(&crc->lock);
+
+ crtc->funcs->set_crc_source(crtc, NULL, &values_cnt);
+
+ return 0;
+}
+
+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);
+}
+
+/*
+ * 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);
+}
+
+const struct file_operations drm_crtc_crc_data_fops = {
+ .owner = THIS_MODULE,
+ .open = crtc_crc_open,
+ .read = crtc_crc_read,
+ .release = crtc_crc_release,
+};
+
+/**
+ * drm_debugfs_crtc_crc_add - Add files to debugfs for capture of frame CRCs
+ * @crtc: CRTC to whom the frames will belong
+ *
+ * Adds files to debugfs directory that allows userspace to control the
+ * generation of frame CRCs and to read them.
+ *
+ * Returns:
+ * Zero on success, error code on failure.
+ */
+int drm_debugfs_crtc_crc_add(struct drm_crtc *crtc)
+{
+ struct dentry *crc_ent, *ent;
+
+ if (!crtc->funcs->set_crc_source)
+ return 0;
+
+ crc_ent = debugfs_create_dir("crc", crtc->debugfs_entry);
+ if (!crc_ent)
+ return -ENOMEM;
+
+ ent = debugfs_create_file("control", S_IRUGO, crc_ent, crtc,
+ &drm_crtc_crc_control_fops);
+ if (!ent)
+ goto error;
+
+ ent = debugfs_create_file("data", S_IRUGO, crc_ent, crtc,
+ &drm_crtc_crc_data_fops);
+ if (!ent)
+ goto error;
+
+ return 0;
+
+error:
+ debugfs_remove_recursive(crc_ent);
+
+ return -ENOMEM;
+}
+
+/**
+ * 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;
+
+ assert_spin_locked(&crc->lock);
+
+ /* Caller may not have noticed yet that userspace has stopped reading */
+ if (!crc->opened)
+ return -EINVAL;
+
+ head = crc->head;
+ tail = crc->tail;
+
+ if (CIRC_SPACE(head, tail, DRM_CRC_ENTRIES_NR) < 1) {
+ 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;
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(drm_crtc_add_crc_entry);
--- /dev/null
+/*
+ * 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 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 COPYRIGHT HOLDER(S) OR AUTHOR(S) 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.
+ */
+#ifndef __DRM_DEBUGFS_CRC_H__
+#define __DRM_DEBUGFS_CRC_H__
+
+#define DRM_MAX_CRC_NR 10
+
+/**
+ * struct drm_crtc_crc_entry - entry describing a frame's content
+ * @has_frame_counter: whether the source was able to provide a frame number
+ * @frame: number of the frame this CRC is about, if @has_frame_counter is true
+ * @crc: array of values that characterize the frame
+ */
+struct drm_crtc_crc_entry {
+ bool has_frame_counter;
+ uint32_t frame;
+ uint32_t crcs[DRM_MAX_CRC_NR];
+};
+
+#define DRM_CRC_ENTRIES_NR 128
+
+/**
+ * struct drm_crtc_crc - data supporting CRC capture on a given CRTC
+ * @lock: protects the fields in this struct
+ * @source: name of the currently configured source of CRCs
+ * @opened: whether userspace has opened the data file for reading
+ * @entries: array of entries, with size of %DRM_CRC_ENTRIES_NR
+ * @head: head of circular queue
+ * @tail: tail of circular queue
+ * @values_cnt: number of CRC values per entry, up to %DRM_MAX_CRC_NR
+ * @wq: workqueue used to synchronize reading and writing
+ */
+struct drm_crtc_crc {
+ spinlock_t lock;
+ const char *source;
+ bool opened;
+ struct drm_crtc_crc_entry *entries;
+ int head, tail;
+ size_t values_cnt;
+ wait_queue_head_t wq;
+};
+
+#if defined(CONFIG_DEBUG_FS)
+int drm_crtc_add_crc_entry(struct drm_crtc *crtc, bool has_frame,
+ uint32_t frame, uint32_t *crcs);
+#else
+static inline int drm_crtc_add_crc_entry(struct drm_crtc *crtc, bool has_frame,
+ uint32_t frame, uint32_t *crcs)
+{
+ return -EINVAL;
+}
+#endif /* defined(CONFIG_DEBUG_FS) */
+
+#endif /* __DRM_DEBUGFS_CRC_H__ */
projects / GitHub / MotorolaMobilityLLC / kernel-slsi.git / commitdiff