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![Dingchen Zhang](/assets/img/avatar_default.png)
to terminate the while-loop in drm_dp_aux_crc_work when drm_dp_start/stop_crc are called in the hook to set crc source. v3: set crc->opened to false without checking (Nick) v2: Move spin_lock around entire crc->opened use (Daniel) Cc: Daniel Vetter <daniel@ffwll.ch> Cc: Harry Wentland <Harry.Wentland@amd.com> Cc: Nick Kazlauskas <Nicholas.Kazlauskas@amd.com> Signed-off-by: Dingchen Zhang <dingchen.zhang@amd.com> Reviewed-by: Harry Wentland <harry.wentland@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> Link: https://patchwork.freedesktop.org/patch/msgid/20190726173743.11641-1-dingchen.zhang@amd.com
436 lines
12 KiB
C
436 lines
12 KiB
C
/*
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* Copyright © 2008 Intel Corporation
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* Copyright © 2016 Collabora Ltd
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*
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* Permission is hereby granted, free of charge, to any person obtaining a
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* copy of this software and associated documentation files (the "Software"),
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* to deal in the Software without restriction, including without limitation
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* the rights to use, copy, modify, merge, publish, distribute, sublicense,
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* and/or sell copies of the Software, and to permit persons to whom the
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* Software is furnished to do so, subject to the following conditions:
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*
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* The above copyright notice and this permission notice (including the next
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* paragraph) shall be included in all copies or substantial portions of the
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* Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
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* IN THE SOFTWARE.
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*
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* Based on code from the i915 driver.
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* Original author: Damien Lespiau <damien.lespiau@intel.com>
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*
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*/
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#include <linux/circ_buf.h>
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#include <linux/ctype.h>
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#include <linux/debugfs.h>
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#include <linux/poll.h>
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#include <linux/uaccess.h>
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#include <drm/drm_crtc.h>
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#include <drm/drm_debugfs_crc.h>
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#include <drm/drm_drv.h>
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#include <drm/drm_print.h>
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#include "drm_internal.h"
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/**
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* DOC: CRC ABI
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*
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* DRM device drivers can provide to userspace CRC information of each frame as
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* it reached a given hardware component (a CRC sampling "source").
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*
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* Userspace can control generation of CRCs in a given CRTC by writing to the
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* file dri/0/crtc-N/crc/control in debugfs, with N being the index of the CRTC.
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* Accepted values are source names (which are driver-specific) and the "auto"
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* keyword, which will let the driver select a default source of frame CRCs
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* for this CRTC.
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*
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* Once frame CRC generation is enabled, userspace can capture them by reading
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* the dri/0/crtc-N/crc/data file. Each line in that file contains the frame
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* number in the first field and then a number of unsigned integer fields
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* containing the CRC data. Fields are separated by a single space and the number
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* of CRC fields is source-specific.
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*
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* Note that though in some cases the CRC is computed in a specified way and on
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* the frame contents as supplied by userspace (eDP 1.3), in general the CRC
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* computation is performed in an unspecified way and on frame contents that have
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* been already processed in also an unspecified way and thus userspace cannot
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* rely on being able to generate matching CRC values for the frame contents that
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* it submits. In this general case, the maximum userspace can do is to compare
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* the reported CRCs of frames that should have the same contents.
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*
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* On the driver side the implementation effort is minimal, drivers only need to
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* implement &drm_crtc_funcs.set_crc_source and &drm_crtc_funcs.verify_crc_source.
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* The debugfs files are automatically set up if those vfuncs are set. CRC samples
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* need to be captured in the driver by calling drm_crtc_add_crc_entry().
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* Depending on the driver and HW requirements, &drm_crtc_funcs.set_crc_source
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* may result in a commit (even a full modeset).
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*
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* CRC results must be reliable across non-full-modeset atomic commits, so if a
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* commit via DRM_IOCTL_MODE_ATOMIC would disable or otherwise interfere with
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* CRC generation, then the driver must mark that commit as a full modeset
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* (drm_atomic_crtc_needs_modeset() should return true). As a result, to ensure
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* consistent results, generic userspace must re-setup CRC generation after a
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* legacy SETCRTC or an atomic commit with DRM_MODE_ATOMIC_ALLOW_MODESET.
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*/
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static int crc_control_show(struct seq_file *m, void *data)
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{
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struct drm_crtc *crtc = m->private;
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if (crtc->funcs->get_crc_sources) {
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size_t count;
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const char *const *sources = crtc->funcs->get_crc_sources(crtc,
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&count);
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size_t values_cnt;
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int i;
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if (count == 0 || !sources)
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goto out;
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for (i = 0; i < count; i++)
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if (!crtc->funcs->verify_crc_source(crtc, sources[i],
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&values_cnt)) {
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if (strcmp(sources[i], crtc->crc.source))
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seq_printf(m, "%s\n", sources[i]);
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else
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seq_printf(m, "%s*\n", sources[i]);
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}
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}
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return 0;
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out:
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seq_printf(m, "%s*\n", crtc->crc.source);
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return 0;
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}
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static int crc_control_open(struct inode *inode, struct file *file)
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{
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struct drm_crtc *crtc = inode->i_private;
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return single_open(file, crc_control_show, crtc);
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}
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static ssize_t crc_control_write(struct file *file, const char __user *ubuf,
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size_t len, loff_t *offp)
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{
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struct seq_file *m = file->private_data;
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struct drm_crtc *crtc = m->private;
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struct drm_crtc_crc *crc = &crtc->crc;
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char *source;
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size_t values_cnt;
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int ret;
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if (len == 0)
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return 0;
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if (len > PAGE_SIZE - 1) {
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DRM_DEBUG_KMS("Expected < %lu bytes into crtc crc control\n",
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PAGE_SIZE);
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return -E2BIG;
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}
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source = memdup_user_nul(ubuf, len);
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if (IS_ERR(source))
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return PTR_ERR(source);
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if (source[len - 1] == '\n')
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source[len - 1] = '\0';
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ret = crtc->funcs->verify_crc_source(crtc, source, &values_cnt);
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if (ret)
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return ret;
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spin_lock_irq(&crc->lock);
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if (crc->opened) {
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spin_unlock_irq(&crc->lock);
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kfree(source);
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return -EBUSY;
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}
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kfree(crc->source);
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crc->source = source;
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spin_unlock_irq(&crc->lock);
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*offp += len;
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return len;
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}
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static const struct file_operations drm_crtc_crc_control_fops = {
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.owner = THIS_MODULE,
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.open = crc_control_open,
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.read = seq_read,
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.llseek = seq_lseek,
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.release = single_release,
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.write = crc_control_write
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};
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static int crtc_crc_data_count(struct drm_crtc_crc *crc)
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{
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assert_spin_locked(&crc->lock);
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return CIRC_CNT(crc->head, crc->tail, DRM_CRC_ENTRIES_NR);
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}
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static void crtc_crc_cleanup(struct drm_crtc_crc *crc)
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{
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kfree(crc->entries);
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crc->overflow = false;
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crc->entries = NULL;
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crc->head = 0;
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crc->tail = 0;
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crc->values_cnt = 0;
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crc->opened = false;
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}
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static int crtc_crc_open(struct inode *inode, struct file *filep)
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{
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struct drm_crtc *crtc = inode->i_private;
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struct drm_crtc_crc *crc = &crtc->crc;
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struct drm_crtc_crc_entry *entries = NULL;
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size_t values_cnt;
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int ret = 0;
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if (drm_drv_uses_atomic_modeset(crtc->dev)) {
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ret = drm_modeset_lock_single_interruptible(&crtc->mutex);
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if (ret)
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return ret;
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if (!crtc->state->active)
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ret = -EIO;
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drm_modeset_unlock(&crtc->mutex);
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if (ret)
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return ret;
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}
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ret = crtc->funcs->verify_crc_source(crtc, crc->source, &values_cnt);
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if (ret)
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return ret;
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if (WARN_ON(values_cnt > DRM_MAX_CRC_NR))
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return -EINVAL;
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if (WARN_ON(values_cnt == 0))
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return -EINVAL;
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entries = kcalloc(DRM_CRC_ENTRIES_NR, sizeof(*entries), GFP_KERNEL);
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if (!entries)
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return -ENOMEM;
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spin_lock_irq(&crc->lock);
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if (!crc->opened) {
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crc->opened = true;
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crc->entries = entries;
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crc->values_cnt = values_cnt;
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} else {
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ret = -EBUSY;
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}
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spin_unlock_irq(&crc->lock);
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if (ret) {
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kfree(entries);
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return ret;
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}
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ret = crtc->funcs->set_crc_source(crtc, crc->source);
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if (ret)
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goto err;
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return 0;
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err:
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spin_lock_irq(&crc->lock);
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crtc_crc_cleanup(crc);
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spin_unlock_irq(&crc->lock);
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return ret;
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}
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static int crtc_crc_release(struct inode *inode, struct file *filep)
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{
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struct drm_crtc *crtc = filep->f_inode->i_private;
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struct drm_crtc_crc *crc = &crtc->crc;
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/* terminate the infinite while loop if 'drm_dp_aux_crc_work' running */
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spin_lock_irq(&crc->lock);
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crc->opened = false;
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spin_unlock_irq(&crc->lock);
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crtc->funcs->set_crc_source(crtc, NULL);
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spin_lock_irq(&crc->lock);
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crtc_crc_cleanup(crc);
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spin_unlock_irq(&crc->lock);
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return 0;
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}
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/*
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* 1 frame field of 10 chars plus a number of CRC fields of 10 chars each, space
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* separated, with a newline at the end and null-terminated.
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*/
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#define LINE_LEN(values_cnt) (10 + 11 * values_cnt + 1 + 1)
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#define MAX_LINE_LEN (LINE_LEN(DRM_MAX_CRC_NR))
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static ssize_t crtc_crc_read(struct file *filep, char __user *user_buf,
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size_t count, loff_t *pos)
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{
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struct drm_crtc *crtc = filep->f_inode->i_private;
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struct drm_crtc_crc *crc = &crtc->crc;
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struct drm_crtc_crc_entry *entry;
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char buf[MAX_LINE_LEN];
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int ret, i;
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spin_lock_irq(&crc->lock);
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if (!crc->source) {
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spin_unlock_irq(&crc->lock);
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return 0;
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}
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/* Nothing to read? */
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while (crtc_crc_data_count(crc) == 0) {
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if (filep->f_flags & O_NONBLOCK) {
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spin_unlock_irq(&crc->lock);
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return -EAGAIN;
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}
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ret = wait_event_interruptible_lock_irq(crc->wq,
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crtc_crc_data_count(crc),
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crc->lock);
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if (ret) {
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spin_unlock_irq(&crc->lock);
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return ret;
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}
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}
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/* We know we have an entry to be read */
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entry = &crc->entries[crc->tail];
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if (count < LINE_LEN(crc->values_cnt)) {
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spin_unlock_irq(&crc->lock);
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return -EINVAL;
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}
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BUILD_BUG_ON_NOT_POWER_OF_2(DRM_CRC_ENTRIES_NR);
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crc->tail = (crc->tail + 1) & (DRM_CRC_ENTRIES_NR - 1);
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spin_unlock_irq(&crc->lock);
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if (entry->has_frame_counter)
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sprintf(buf, "0x%08x", entry->frame);
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else
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sprintf(buf, "XXXXXXXXXX");
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for (i = 0; i < crc->values_cnt; i++)
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sprintf(buf + 10 + i * 11, " 0x%08x", entry->crcs[i]);
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sprintf(buf + 10 + crc->values_cnt * 11, "\n");
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if (copy_to_user(user_buf, buf, LINE_LEN(crc->values_cnt)))
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return -EFAULT;
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return LINE_LEN(crc->values_cnt);
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}
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static __poll_t crtc_crc_poll(struct file *file, poll_table *wait)
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{
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struct drm_crtc *crtc = file->f_inode->i_private;
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struct drm_crtc_crc *crc = &crtc->crc;
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__poll_t ret = 0;
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poll_wait(file, &crc->wq, wait);
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spin_lock_irq(&crc->lock);
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if (crc->source && crtc_crc_data_count(crc))
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ret |= EPOLLIN | EPOLLRDNORM;
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spin_unlock_irq(&crc->lock);
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return ret;
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}
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static const struct file_operations drm_crtc_crc_data_fops = {
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.owner = THIS_MODULE,
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.open = crtc_crc_open,
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.read = crtc_crc_read,
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.poll = crtc_crc_poll,
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.release = crtc_crc_release,
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};
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void drm_debugfs_crtc_crc_add(struct drm_crtc *crtc)
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{
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struct dentry *crc_ent;
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if (!crtc->funcs->set_crc_source || !crtc->funcs->verify_crc_source)
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return;
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crc_ent = debugfs_create_dir("crc", crtc->debugfs_entry);
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debugfs_create_file("control", S_IRUGO, crc_ent, crtc,
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&drm_crtc_crc_control_fops);
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debugfs_create_file("data", S_IRUGO, crc_ent, crtc,
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&drm_crtc_crc_data_fops);
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}
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/**
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* drm_crtc_add_crc_entry - Add entry with CRC information for a frame
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* @crtc: CRTC to which the frame belongs
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* @has_frame: whether this entry has a frame number to go with
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* @frame: number of the frame these CRCs are about
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* @crcs: array of CRC values, with length matching #drm_crtc_crc.values_cnt
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*
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* For each frame, the driver polls the source of CRCs for new data and calls
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* this function to add them to the buffer from where userspace reads.
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*/
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int drm_crtc_add_crc_entry(struct drm_crtc *crtc, bool has_frame,
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uint32_t frame, uint32_t *crcs)
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{
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struct drm_crtc_crc *crc = &crtc->crc;
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struct drm_crtc_crc_entry *entry;
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int head, tail;
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unsigned long flags;
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spin_lock_irqsave(&crc->lock, flags);
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/* Caller may not have noticed yet that userspace has stopped reading */
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if (!crc->entries) {
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spin_unlock_irqrestore(&crc->lock, flags);
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return -EINVAL;
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}
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head = crc->head;
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tail = crc->tail;
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if (CIRC_SPACE(head, tail, DRM_CRC_ENTRIES_NR) < 1) {
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bool was_overflow = crc->overflow;
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crc->overflow = true;
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spin_unlock_irqrestore(&crc->lock, flags);
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if (!was_overflow)
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DRM_ERROR("Overflow of CRC buffer, userspace reads too slow.\n");
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return -ENOBUFS;
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}
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entry = &crc->entries[head];
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entry->frame = frame;
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entry->has_frame_counter = has_frame;
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memcpy(&entry->crcs, crcs, sizeof(*crcs) * crc->values_cnt);
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head = (head + 1) & (DRM_CRC_ENTRIES_NR - 1);
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crc->head = head;
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spin_unlock_irqrestore(&crc->lock, flags);
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wake_up_interruptible(&crc->wq);
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return 0;
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}
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EXPORT_SYMBOL_GPL(drm_crtc_add_crc_entry);
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