diff options
Diffstat (limited to 'drivers/gpu/drm/drm_vblank.c')
| -rw-r--r-- | drivers/gpu/drm/drm_vblank.c | 1648 |
1 files changed, 1648 insertions, 0 deletions
diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c new file mode 100644 index 0000000..e9f33cd --- /dev/null +++ b/drivers/gpu/drm/drm_vblank.c @@ -0,0 +1,1648 @@ +/* + * drm_irq.c IRQ and vblank support + * + * \author Rickard E. (Rik) Faith <faith@valinux.com> + * \author Gareth Hughes <gareth@valinux.com> + * + * 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 + * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS 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. + */ + +#include <drm/drm_vblank.h> +#include <drm/drmP.h> +#include <linux/export.h> + +#include "drm_trace.h" +#include "drm_internal.h" + +/* Retry timestamp calculation up to 3 times to satisfy + * drm_timestamp_precision before giving up. + */ +#define DRM_TIMESTAMP_MAXRETRIES 3 + +/* Threshold in nanoseconds for detection of redundant + * vblank irq in drm_handle_vblank(). 1 msec should be ok. + */ +#define DRM_REDUNDANT_VBLIRQ_THRESH_NS 1000000 + +static bool +drm_get_last_vbltimestamp(struct drm_device *dev, unsigned int pipe, + struct timeval *tvblank, bool in_vblank_irq); + +static unsigned int drm_timestamp_precision = 20; /* Default to 20 usecs. */ + +/* + * Default to use monotonic timestamps for wait-for-vblank and page-flip + * complete events. + */ +unsigned int drm_timestamp_monotonic = 1; + +static int drm_vblank_offdelay = 5000; /* Default to 5000 msecs. */ + +module_param_named(vblankoffdelay, drm_vblank_offdelay, int, 0600); +module_param_named(timestamp_precision_usec, drm_timestamp_precision, int, 0600); +module_param_named(timestamp_monotonic, drm_timestamp_monotonic, int, 0600); +MODULE_PARM_DESC(vblankoffdelay, "Delay until vblank irq auto-disable [msecs] (0: never disable, <0: disable immediately)"); +MODULE_PARM_DESC(timestamp_precision_usec, "Max. error on timestamps [usecs]"); +MODULE_PARM_DESC(timestamp_monotonic, "Use monotonic timestamps"); + +static void store_vblank(struct drm_device *dev, unsigned int pipe, + u32 vblank_count_inc, + struct timeval *t_vblank, u32 last) +{ + struct drm_vblank_crtc *vblank = &dev->vblank[pipe]; + + assert_spin_locked(&dev->vblank_time_lock); + + vblank->last = last; + + write_seqlock(&vblank->seqlock); + vblank->time = *t_vblank; + vblank->count += vblank_count_inc; + write_sequnlock(&vblank->seqlock); +} + +/* + * "No hw counter" fallback implementation of .get_vblank_counter() hook, + * if there is no useable hardware frame counter available. + */ +static u32 drm_vblank_no_hw_counter(struct drm_device *dev, unsigned int pipe) +{ + WARN_ON_ONCE(dev->max_vblank_count != 0); + return 0; +} + +static u32 __get_vblank_counter(struct drm_device *dev, unsigned int pipe) +{ + if (drm_core_check_feature(dev, DRIVER_MODESET)) { + struct drm_crtc *crtc = drm_crtc_from_index(dev, pipe); + + if (crtc->funcs->get_vblank_counter) + return crtc->funcs->get_vblank_counter(crtc); + } + + if (dev->driver->get_vblank_counter) + return dev->driver->get_vblank_counter(dev, pipe); + + return drm_vblank_no_hw_counter(dev, pipe); +} + +/* + * Reset the stored timestamp for the current vblank count to correspond + * to the last vblank occurred. + * + * Only to be called from drm_crtc_vblank_on(). + * + * Note: caller must hold &drm_device.vbl_lock since this reads & writes + * device vblank fields. + */ +static void drm_reset_vblank_timestamp(struct drm_device *dev, unsigned int pipe) +{ + u32 cur_vblank; + bool rc; + struct timeval t_vblank; + int count = DRM_TIMESTAMP_MAXRETRIES; + + spin_lock(&dev->vblank_time_lock); + + /* + * sample the current counter to avoid random jumps + * when drm_vblank_enable() applies the diff + */ + do { + cur_vblank = __get_vblank_counter(dev, pipe); + rc = drm_get_last_vbltimestamp(dev, pipe, &t_vblank, false); + } while (cur_vblank != __get_vblank_counter(dev, pipe) && --count > 0); + + /* + * Only reinitialize corresponding vblank timestamp if high-precision query + * available and didn't fail. Otherwise reinitialize delayed at next vblank + * interrupt and assign 0 for now, to mark the vblanktimestamp as invalid. + */ + if (!rc) + t_vblank = (struct timeval) {0, 0}; + + /* + * +1 to make sure user will never see the same + * vblank counter value before and after a modeset + */ + store_vblank(dev, pipe, 1, &t_vblank, cur_vblank); + + spin_unlock(&dev->vblank_time_lock); +} + +/* + * Call back into the driver to update the appropriate vblank counter + * (specified by @pipe). Deal with wraparound, if it occurred, and + * update the last read value so we can deal with wraparound on the next + * call if necessary. + * + * Only necessary when going from off->on, to account for frames we + * didn't get an interrupt for. + * + * Note: caller must hold &drm_device.vbl_lock since this reads & writes + * device vblank fields. + */ +static void drm_update_vblank_count(struct drm_device *dev, unsigned int pipe, + bool in_vblank_irq) +{ + struct drm_vblank_crtc *vblank = &dev->vblank[pipe]; + u32 cur_vblank, diff; + bool rc; + struct timeval t_vblank; + int count = DRM_TIMESTAMP_MAXRETRIES; + int framedur_ns = vblank->framedur_ns; + + /* + * Interrupts were disabled prior to this call, so deal with counter + * wrap if needed. + * NOTE! It's possible we lost a full dev->max_vblank_count + 1 events + * here if the register is small or we had vblank interrupts off for + * a long time. + * + * We repeat the hardware vblank counter & timestamp query until + * we get consistent results. This to prevent races between gpu + * updating its hardware counter while we are retrieving the + * corresponding vblank timestamp. + */ + do { + cur_vblank = __get_vblank_counter(dev, pipe); + rc = drm_get_last_vbltimestamp(dev, pipe, &t_vblank, in_vblank_irq); + } while (cur_vblank != __get_vblank_counter(dev, pipe) && --count > 0); + + if (dev->max_vblank_count != 0) { + /* trust the hw counter when it's around */ + diff = (cur_vblank - vblank->last) & dev->max_vblank_count; + } else if (rc && framedur_ns) { + const struct timeval *t_old; + u64 diff_ns; + + t_old = &vblank->time; + diff_ns = timeval_to_ns(&t_vblank) - timeval_to_ns(t_old); + + /* + * Figure out how many vblanks we've missed based + * on the difference in the timestamps and the + * frame/field duration. + */ + diff = DIV_ROUND_CLOSEST_ULL(diff_ns, framedur_ns); + + if (diff == 0 && in_vblank_irq) + DRM_DEBUG_VBL("crtc %u: Redundant vblirq ignored." + " diff_ns = %lld, framedur_ns = %d)\n", + pipe, (long long) diff_ns, framedur_ns); + } else { + /* some kind of default for drivers w/o accurate vbl timestamping */ + diff = in_vblank_irq ? 1 : 0; + } + + /* + * Within a drm_vblank_pre_modeset - drm_vblank_post_modeset + * interval? If so then vblank irqs keep running and it will likely + * happen that the hardware vblank counter is not trustworthy as it + * might reset at some point in that interval and vblank timestamps + * are not trustworthy either in that interval. Iow. this can result + * in a bogus diff >> 1 which must be avoided as it would cause + * random large forward jumps of the software vblank counter. + */ + if (diff > 1 && (vblank->inmodeset & 0x2)) { + DRM_DEBUG_VBL("clamping vblank bump to 1 on crtc %u: diffr=%u" + " due to pre-modeset.\n", pipe, diff); + diff = 1; + } + + DRM_DEBUG_VBL("updating vblank count on crtc %u:" + " current=%u, diff=%u, hw=%u hw_last=%u\n", + pipe, vblank->count, diff, cur_vblank, vblank->last); + + if (diff == 0) { + WARN_ON_ONCE(cur_vblank != vblank->last); + return; + } + + /* + * Only reinitialize corresponding vblank timestamp if high-precision query + * available and didn't fail, or we were called from the vblank interrupt. + * Otherwise reinitialize delayed at next vblank interrupt and assign 0 + * for now, to mark the vblanktimestamp as invalid. + */ + if (!rc && !in_vblank_irq) + t_vblank = (struct timeval) {0, 0}; + + store_vblank(dev, pipe, diff, &t_vblank, cur_vblank); +} + +static u32 drm_vblank_count(struct drm_device *dev, unsigned int pipe) +{ + struct drm_vblank_crtc *vblank = &dev->vblank[pipe]; + + if (WARN_ON(pipe >= dev->num_crtcs)) + return 0; + + return vblank->count; +} + +/** + * drm_accurate_vblank_count - retrieve the master vblank counter + * @crtc: which counter to retrieve + * + * This function is similar to @drm_crtc_vblank_count but this + * function interpolates to handle a race with vblank irq's. + * + * This is mostly useful for hardware that can obtain the scanout + * position, but doesn't have a frame counter. + */ +u32 drm_accurate_vblank_count(struct drm_crtc *crtc) +{ + struct drm_device *dev = crtc->dev; + unsigned int pipe = drm_crtc_index(crtc); + u32 vblank; + unsigned long flags; + + WARN(!dev->driver->get_vblank_timestamp, + "This function requires support for accurate vblank timestamps."); + + spin_lock_irqsave(&dev->vblank_time_lock, flags); + + drm_update_vblank_count(dev, pipe, false); + vblank = drm_vblank_count(dev, pipe); + + spin_unlock_irqrestore(&dev->vblank_time_lock, flags); + + return vblank; +} +EXPORT_SYMBOL(drm_accurate_vblank_count); + +static void __disable_vblank(struct drm_device *dev, unsigned int pipe) +{ + if (drm_core_check_feature(dev, DRIVER_MODESET)) { + struct drm_crtc *crtc = drm_crtc_from_index(dev, pipe); + + if (crtc->funcs->disable_vblank) { + crtc->funcs->disable_vblank(crtc); + return; + } + } + + dev->driver->disable_vblank(dev, pipe); +} + +/* + * Disable vblank irq's on crtc, make sure that last vblank count + * of hardware and corresponding consistent software vblank counter + * are preserved, even if there are any spurious vblank irq's after + * disable. + */ +void drm_vblank_disable_and_save(struct drm_device *dev, unsigned int pipe) +{ + struct drm_vblank_crtc *vblank = &dev->vblank[pipe]; + unsigned long irqflags; + + assert_spin_locked(&dev->vbl_lock); + + /* Prevent vblank irq processing while disabling vblank irqs, + * so no updates of timestamps or count can happen after we've + * disabled. Needed to prevent races in case of delayed irq's. + */ + spin_lock_irqsave(&dev->vblank_time_lock, irqflags); + + /* + * Only disable vblank interrupts if they're enabled. This avoids + * calling the ->disable_vblank() operation in atomic context with the + * hardware potentially runtime suspended. + */ + if (vblank->enabled) { + __disable_vblank(dev, pipe); + vblank->enabled = false; + } + + /* + * Always update the count and timestamp to maintain the + * appearance that the counter has been ticking all along until + * this time. This makes the count account for the entire time + * between drm_crtc_vblank_on() and drm_crtc_vblank_off(). + */ + drm_update_vblank_count(dev, pipe, false); + + spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags); +} + +static void vblank_disable_fn(unsigned long arg) +{ + struct drm_vblank_crtc *vblank = (void *)arg; + struct drm_device *dev = vblank->dev; + unsigned int pipe = vblank->pipe; + unsigned long irqflags; + + spin_lock_irqsave(&dev->vbl_lock, irqflags); + if (atomic_read(&vblank->refcount) == 0 && vblank->enabled) { + DRM_DEBUG("disabling vblank on crtc %u\n", pipe); + drm_vblank_disable_and_save(dev, pipe); + } + spin_unlock_irqrestore(&dev->vbl_lock, irqflags); +} + +/** + * drm_vblank_cleanup - cleanup vblank support + * @dev: DRM device + * + * This function cleans up any resources allocated in drm_vblank_init. + * + * Drivers which don't use drm_irq_install() need to set &drm_device.irq_enabled + * themselves, to signal to the DRM core that vblank interrupts are enabled. + */ +void drm_vblank_cleanup(struct drm_device *dev) +{ + unsigned int pipe; + + /* Bail if the driver didn't call drm_vblank_init() */ + if (dev->num_crtcs == 0) + return; + + for (pipe = 0; pipe < dev->num_crtcs; pipe++) { + struct drm_vblank_crtc *vblank = &dev->vblank[pipe]; + + WARN_ON(READ_ONCE(vblank->enabled) && + drm_core_check_feature(dev, DRIVER_MODESET)); + + del_timer_sync(&vblank->disable_timer); + } + + kfree(dev->vblank); + + dev->num_crtcs = 0; +} +EXPORT_SYMBOL(drm_vblank_cleanup); + +/** + * drm_vblank_init - initialize vblank support + * @dev: DRM device + * @num_crtcs: number of CRTCs supported by @dev + * + * This function initializes vblank support for @num_crtcs display pipelines. + * + * Returns: + * Zero on success or a negative error code on failure. + */ +int drm_vblank_init(struct drm_device *dev, unsigned int num_crtcs) +{ + int ret = -ENOMEM; + unsigned int i; + + spin_lock_init(&dev->vbl_lock); + spin_lock_init(&dev->vblank_time_lock); + + dev->num_crtcs = num_crtcs; + + dev->vblank = kcalloc(num_crtcs, sizeof(*dev->vblank), GFP_KERNEL); + if (!dev->vblank) + goto err; + + for (i = 0; i < num_crtcs; i++) { + struct drm_vblank_crtc *vblank = &dev->vblank[i]; + + vblank->dev = dev; + vblank->pipe = i; + init_waitqueue_head(&vblank->queue); + setup_timer(&vblank->disable_timer, vblank_disable_fn, + (unsigned long)vblank); + seqlock_init(&vblank->seqlock); + } + + DRM_INFO("Supports vblank timestamp caching Rev 2 (21.10.2013).\n"); + + /* Driver specific high-precision vblank timestamping supported? */ + if (dev->driver->get_vblank_timestamp) + DRM_INFO("Driver supports precise vblank timestamp query.\n"); + else + DRM_INFO("No driver support for vblank timestamp query.\n"); + + /* Must have precise timestamping for reliable vblank instant disable */ + if (dev->vblank_disable_immediate && !dev->driver->get_vblank_timestamp) { + dev->vblank_disable_immediate = false; + DRM_INFO("Setting vblank_disable_immediate to false because " + "get_vblank_timestamp == NULL\n"); + } + + return 0; + +err: + dev->num_crtcs = 0; + return ret; +} +EXPORT_SYMBOL(drm_vblank_init); + +/** + * drm_crtc_vblank_waitqueue - get vblank waitqueue for the CRTC + * @crtc: which CRTC's vblank waitqueue to retrieve + * + * This function returns a pointer to the vblank waitqueue for the CRTC. + * Drivers can use this to implement vblank waits using wait_event() and related + * functions. + */ +wait_queue_head_t *drm_crtc_vblank_waitqueue(struct drm_crtc *crtc) +{ + return &crtc->dev->vblank[drm_crtc_index(crtc)].queue; +} +EXPORT_SYMBOL(drm_crtc_vblank_waitqueue); + + +/** + * drm_calc_timestamping_constants - calculate vblank timestamp constants + * @crtc: drm_crtc whose timestamp constants should be updated. + * @mode: display mode containing the scanout timings + * + * Calculate and store various constants which are later + * needed by vblank and swap-completion timestamping, e.g, + * by drm_calc_vbltimestamp_from_scanoutpos(). They are + * derived from CRTC's true scanout timing, so they take + * things like panel scaling or other adjustments into account. + */ +void drm_calc_timestamping_constants(struct drm_crtc *crtc, + const struct drm_display_mode *mode) +{ + struct drm_device *dev = crtc->dev; + unsigned int pipe = drm_crtc_index(crtc); + struct drm_vblank_crtc *vblank = &dev->vblank[pipe]; + int linedur_ns = 0, framedur_ns = 0; + int dotclock = mode->crtc_clock; + + if (!dev->num_crtcs) + return; + + if (WARN_ON(pipe >= dev->num_crtcs)) + return; + + /* Valid dotclock? */ + if (dotclock > 0) { + int frame_size = mode->crtc_htotal * mode->crtc_vtotal; + + /* + * Convert scanline length in pixels and video + * dot clock to line duration and frame duration + * in nanoseconds: + */ + linedur_ns = div_u64((u64) mode->crtc_htotal * 1000000, dotclock); + framedur_ns = div_u64((u64) frame_size * 1000000, dotclock); + + /* + * Fields of interlaced scanout modes are only half a frame duration. + */ + if (mode->flags & DRM_MODE_FLAG_INTERLACE) + framedur_ns /= 2; + } else + DRM_ERROR("crtc %u: Can't calculate constants, dotclock = 0!\n", + crtc->base.id); + + vblank->linedur_ns = linedur_ns; + vblank->framedur_ns = framedur_ns; + vblank->hwmode = *mode; + + DRM_DEBUG("crtc %u: hwmode: htotal %d, vtotal %d, vdisplay %d\n", + crtc->base.id, mode->crtc_htotal, + mode->crtc_vtotal, mode->crtc_vdisplay); + DRM_DEBUG("crtc %u: clock %d kHz framedur %d linedur %d\n", + crtc->base.id, dotclock, framedur_ns, linedur_ns); +} +EXPORT_SYMBOL(drm_calc_timestamping_constants); + +/** + * drm_calc_vbltimestamp_from_scanoutpos - precise vblank timestamp helper + * @dev: DRM device + * @pipe: index of CRTC whose vblank timestamp to retrieve + * @max_error: Desired maximum allowable error in timestamps (nanosecs) + * On return contains true maximum error of timestamp + * @vblank_time: Pointer to struct timeval which should receive the timestamp + * @in_vblank_irq: + * True when called from drm_crtc_handle_vblank(). Some drivers + * need to apply some workarounds for gpu-specific vblank irq quirks + * if flag is set. + * + * Implements calculation of exact vblank timestamps from given drm_display_mode + * timings and current video scanout position of a CRTC. This can be called from + * within get_vblank_timestamp() implementation of a kms driver to implement the + * actual timestamping. + * + * Should return timestamps conforming to the OML_sync_control OpenML + * extension specification. The timestamp corresponds to the end of + * the vblank interval, aka start of scanout of topmost-leftmost display + * pixel in the following video frame. + * + * Requires support for optional dev->driver->get_scanout_position() + * in kms driver, plus a bit of setup code to provide a drm_display_mode + * that corresponds to the true scanout timing. + * + * The current implementation only handles standard video modes. It + * returns as no operation if a doublescan or interlaced video mode is + * active. Higher level code is expected to handle this. + * + * This function can be used to implement the &drm_driver.get_vblank_timestamp + * directly, if the driver implements the &drm_driver.get_scanout_position hook. + * + * Note that atomic drivers must call drm_calc_timestamping_constants() before + * enabling a CRTC. The atomic helpers already take care of that in + * drm_atomic_helper_update_legacy_modeset_state(). + * + * Returns: + * + * Returns true on success, and false on failure, i.e. when no accurate + * timestamp could be acquired. + */ +bool drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev, + unsigned int pipe, + int *max_error, + struct timeval *vblank_time, + bool in_vblank_irq) +{ + struct timeval tv_etime; + ktime_t stime, etime; + bool vbl_status; + struct drm_crtc *crtc; + const struct drm_display_mode *mode; + struct drm_vblank_crtc *vblank = &dev->vblank[pipe]; + int vpos, hpos, i; + int delta_ns, duration_ns; + + if (!drm_core_check_feature(dev, DRIVER_MODESET)) + return false; + + crtc = drm_crtc_from_index(dev, pipe); + + if (pipe >= dev->num_crtcs || !crtc) { + DRM_ERROR("Invalid crtc %u\n", pipe); + return false; + } + + /* Scanout position query not supported? Should not happen. */ + if (!dev->driver->get_scanout_position) { + DRM_ERROR("Called from driver w/o get_scanout_position()!?\n"); + return false; + } + + if (drm_drv_uses_atomic_modeset(dev)) + mode = &vblank->hwmode; + else + mode = &crtc->hwmode; + + /* If mode timing undefined, just return as no-op: + * Happens during initial modesetting of a crtc. + */ + if (mode->crtc_clock == 0) { + DRM_DEBUG("crtc %u: Noop due to uninitialized mode.\n", pipe); + WARN_ON_ONCE(drm_drv_uses_atomic_modeset(dev)); + + return false; + } + + /* Get current scanout position with system timestamp. + * Repeat query up to DRM_TIMESTAMP_MAXRETRIES times + * if single query takes longer than max_error nanoseconds. + * + * This guarantees a tight bound on maximum error if + * code gets preempted or delayed for some reason. + */ + for (i = 0; i < DRM_TIMESTAMP_MAXRETRIES; i++) { + /* + * Get vertical and horizontal scanout position vpos, hpos, + * and bounding timestamps stime, etime, pre/post query. + */ + vbl_status = dev->driver->get_scanout_position(dev, pipe, + in_vblank_irq, + &vpos, &hpos, + &stime, &etime, + mode); + + /* Return as no-op if scanout query unsupported or failed. */ + if (!vbl_status) { + DRM_DEBUG("crtc %u : scanoutpos query failed.\n", + pipe); + return false; + } + + /* Compute uncertainty in timestamp of scanout position query. */ + duration_ns = ktime_to_ns(etime) - ktime_to_ns(stime); + + /* Accept result with < max_error nsecs timing uncertainty. */ + if (duration_ns <= *max_error) + break; + } + + /* Noisy system timing? */ + if (i == DRM_TIMESTAMP_MAXRETRIES) { + DRM_DEBUG("crtc %u: Noisy timestamp %d us > %d us [%d reps].\n", + pipe, duration_ns/1000, *max_error/1000, i); + } + + /* Return upper bound of timestamp precision error. */ + *max_error = duration_ns; + + /* Convert scanout position into elapsed time at raw_time query + * since start of scanout at first display scanline. delta_ns + * can be negative if start of scanout hasn't happened yet. + */ + delta_ns = div_s64(1000000LL * (vpos * mode->crtc_htotal + hpos), + mode->crtc_clock); + + if (!drm_timestamp_monotonic) + etime = ktime_mono_to_real(etime); + + /* save this only for debugging purposes */ + tv_etime = ktime_to_timeval(etime); + /* Subtract time delta from raw timestamp to get final + * vblank_time timestamp for end of vblank. + */ + etime = ktime_sub_ns(etime, delta_ns); + *vblank_time = ktime_to_timeval(etime); + + DRM_DEBUG_VBL("crtc %u : v p(%d,%d)@ %ld.%ld -> %ld.%ld [e %d us, %d rep]\n", + pipe, hpos, vpos, + (long)tv_etime.tv_sec, (long)tv_etime.tv_usec, + (long)vblank_time->tv_sec, (long)vblank_time->tv_usec, + duration_ns/1000, i); + + return true; +} +EXPORT_SYMBOL(drm_calc_vbltimestamp_from_scanoutpos); + +static struct timeval get_drm_timestamp(void) +{ + ktime_t now; + + now = drm_timestamp_monotonic ? ktime_get() : ktime_get_real(); + return ktime_to_timeval(now); +} + +/** + * drm_get_last_vbltimestamp - retrieve raw timestamp for the most recent + * vblank interval + * @dev: DRM device + * @pipe: index of CRTC whose vblank timestamp to retrieve + * @tvblank: Pointer to target struct timeval which should receive the timestamp + * @in_vblank_irq: + * True when called from drm_crtc_handle_vblank(). Some drivers + * need to apply some workarounds for gpu-specific vblank irq quirks + * if flag is set. + * + * Fetches the system timestamp corresponding to the time of the most recent + * vblank interval on specified CRTC. May call into kms-driver to + * compute the timestamp with a high-precision GPU specific method. + * + * Returns zero if timestamp originates from uncorrected do_gettimeofday() + * call, i.e., it isn't very precisely locked to the true vblank. + * + * Returns: + * True if timestamp is considered to be very precise, false otherwise. + */ +static bool +drm_get_last_vbltimestamp(struct drm_device *dev, unsigned int pipe, + struct timeval *tvblank, bool in_vblank_irq) +{ + bool ret = false; + + /* Define requested maximum error on timestamps (nanoseconds). */ + int max_error = (int) drm_timestamp_precision * 1000; + + /* Query driver if possible and precision timestamping enabled. */ + if (dev->driver->get_vblank_timestamp && (max_error > 0)) + ret = dev->driver->get_vblank_timestamp(dev, pipe, &max_error, + tvblank, in_vblank_irq); + + /* GPU high precision timestamp query unsupported or failed. + * Return current monotonic/gettimeofday timestamp as best estimate. + */ + if (!ret) + *tvblank = get_drm_timestamp(); + + return ret; +} + +/** + * drm_crtc_vblank_count - retrieve "cooked" vblank counter value + * @crtc: which counter to retrieve + * + * Fetches the "cooked" vblank count value that represents the number of + * vblank events since the system was booted, including lost events due to + * modesetting activity. + * + * Returns: + * The software vblank counter. + */ +u32 drm_crtc_vblank_count(struct drm_crtc *crtc) +{ + return drm_vblank_count(crtc->dev, drm_crtc_index(crtc)); +} +EXPORT_SYMBOL(drm_crtc_vblank_count); + +/** + * drm_vblank_count_and_time - retrieve "cooked" vblank counter value and the + * system timestamp corresponding to that vblank counter value. + * @dev: DRM device + * @pipe: index of CRTC whose counter to retrieve + * @vblanktime: Pointer to struct timeval to receive the vblank timestamp. + * + * Fetches the "cooked" vblank count value that represents the number of + * vblank events since the system was booted, including lost events due to + * modesetting activity. Returns corresponding system timestamp of the time + * of the vblank interval that corresponds to the current vblank counter value. + * + * This is the legacy version of drm_crtc_vblank_count_and_time(). + */ +static u32 drm_vblank_count_and_time(struct drm_device *dev, unsigned int pipe, + struct timeval *vblanktime) +{ + struct drm_vblank_crtc *vblank = &dev->vblank[pipe]; + u32 vblank_count; + unsigned int seq; + + if (WARN_ON(pipe >= dev->num_crtcs)) { + *vblanktime = (struct timeval) { 0 }; + return 0; + } + + do { + seq = read_seqbegin(&vblank->seqlock); + vblank_count = vblank->count; + *vblanktime = vblank->time; + } while (read_seqretry(&vblank->seqlock, seq)); + + return vblank_count; +} + +/** + * drm_crtc_vblank_count_and_time - retrieve "cooked" vblank counter value + * and the system timestamp corresponding to that vblank counter value + * @crtc: which counter to retrieve + * @vblanktime: Pointer to struct timeval to receive the vblank timestamp. + * + * Fetches the "cooked" vblank count value that represents the number of + * vblank events since the system was booted, including lost events due to + * modesetting activity. Returns corresponding system timestamp of the time + * of the vblank interval that corresponds to the current vblank counter value. + */ +u32 drm_crtc_vblank_count_and_time(struct drm_crtc *crtc, + struct timeval *vblanktime) +{ + return drm_vblank_count_and_time(crtc->dev, drm_crtc_index(crtc), + vblanktime); +} +EXPORT_SYMBOL(drm_crtc_vblank_count_and_time); + +static void send_vblank_event(struct drm_device *dev, + struct drm_pending_vblank_event *e, + unsigned long seq, struct timeval *now) +{ + e->event.sequence = seq; + e->event.tv_sec = now->tv_sec; + e->event.tv_usec = now->tv_usec; + + trace_drm_vblank_event_delivered(e->base.file_priv, e->pipe, + e->event.sequence); + + drm_send_event_locked(dev, &e->base); +} + +/** + * drm_crtc_arm_vblank_event - arm vblank event after pageflip + * @crtc: the source CRTC of the vblank event + * @e: the event to send + * + * A lot of drivers need to generate vblank events for the very next vblank + * interrupt. For example when the page flip interrupt happens when the page + * flip gets armed, but not when it actually executes within the next vblank + * period. This helper function implements exactly the required vblank arming + * behaviour. + * + * NOTE: Drivers using this to send out the &drm_crtc_state.event as part of an + * atomic commit must ensure that the next vblank happens at exactly the same + * time as the atomic commit is committed to the hardware. This function itself + * does **not** protect again the next vblank interrupt racing with either this + * function call or the atomic commit operation. A possible sequence could be: + * + * 1. Driver commits new hardware state into vblank-synchronized registers. + * 2. A vblank happens, committing the hardware state. Also the corresponding + * vblank interrupt is fired off and fully processed by the interrupt + * handler. + * 3. The atomic commit operation proceeds to call drm_crtc_arm_vblank_event(). + * 4. The event is only send out for the next vblank, which is wrong. + * + * An equivalent race can happen when the driver calls + * drm_crtc_arm_vblank_event() before writing out the new hardware state. + * + * The only way to make this work safely is to prevent the vblank from firing + * (and the hardware from committing anything else) until the entire atomic + * commit sequence has run to completion. If the hardware does not have such a + * feature (e.g. using a "go" bit), then it is unsafe to use this functions. + * Instead drivers need to manually send out the event from their interrupt + * handler by calling drm_crtc_send_vblank_event() and make sure that there's no + * possible race with the hardware committing the atomic update. + * + * Caller must hold event lock. Caller must also hold a vblank reference for + * the event @e, which will be dropped when the next vblank arrives. + */ +void drm_crtc_arm_vblank_event(struct drm_crtc *crtc, + struct drm_pending_vblank_event *e) +{ + struct drm_device *dev = crtc->dev; + unsigned int pipe = drm_crtc_index(crtc); + + assert_spin_locked(&dev->event_lock); + + e->pipe = pipe; + e->event.sequence = drm_vblank_count(dev, pipe); + e->event.crtc_id = crtc->base.id; + list_add_tail(&e->base.link, &dev->vblank_event_list); +} +EXPORT_SYMBOL(drm_crtc_arm_vblank_event); + +/** + * drm_crtc_send_vblank_event - helper to send vblank event after pageflip + * @crtc: the source CRTC of the vblank event + * @e: the event to send + * + * Updates sequence # and timestamp on event for the most recently processed + * vblank, and sends it to userspace. Caller must hold event lock. + * + * See drm_crtc_arm_vblank_event() for a helper which can be used in certain + * situation, especially to send out events for atomic commit operations. + */ +void drm_crtc_send_vblank_event(struct drm_crtc *crtc, + struct drm_pending_vblank_event *e) +{ + struct drm_device *dev = crtc->dev; + unsigned int seq, pipe = drm_crtc_index(crtc); + struct timeval now; + + if (dev->num_crtcs > 0) { + seq = drm_vblank_count_and_time(dev, pipe, &now); + } else { + seq = 0; + + now = get_drm_timestamp(); + } + e->pipe = pipe; + e->event.crtc_id = crtc->base.id; + send_vblank_event(dev, e, seq, &now); +} +EXPORT_SYMBOL(drm_crtc_send_vblank_event); + +static int __enable_vblank(struct drm_device *dev, unsigned int pipe) +{ + if (drm_core_check_feature(dev, DRIVER_MODESET)) { + struct drm_crtc *crtc = drm_crtc_from_index(dev, pipe); + + if (crtc->funcs->enable_vblank) + return crtc->funcs->enable_vblank(crtc); + } + + return dev->driver->enable_vblank(dev, pipe); +} + +/** + * drm_vblank_enable - enable the vblank interrupt on a CRTC + * @dev: DRM device + * @pipe: CRTC index + * + * Returns: + * Zero on success or a negative error code on failure. + */ +static int drm_vblank_enable(struct drm_device *dev, unsigned int pipe) +{ + struct drm_vblank_crtc *vblank = &dev->vblank[pipe]; + int ret = 0; + + assert_spin_locked(&dev->vbl_lock); + + spin_lock(&dev->vblank_time_lock); + + if (!vblank->enabled) { + /* + * Enable vblank irqs under vblank_time_lock protection. + * All vblank count & timestamp updates are held off + * until we are done reinitializing master counter and + * timestamps. Filtercode in drm_handle_vblank() will + * prevent double-accounting of same vblank interval. + */ + ret = __enable_vblank(dev, pipe); + DRM_DEBUG("enabling vblank on crtc %u, ret: %d\n", pipe, ret); + if (ret) { + atomic_dec(&vblank->refcount); + } else { + drm_update_vblank_count(dev, pipe, 0); + /* drm_update_vblank_count() includes a wmb so we just + * need to ensure that the compiler emits the write + * to mark the vblank as enabled after the call + * to drm_update_vblank_count(). + */ + WRITE_ONCE(vblank->enabled, true); + } + } + + spin_unlock(&dev->vblank_time_lock); + + return ret; +} + +/** + * drm_vblank_get - get a reference count on vblank events + * @dev: DRM device + * @pipe: index of CRTC to own + * + * Acquire a reference count on vblank events to avoid having them disabled + * while in use. + * + * This is the legacy version of drm_crtc_vblank_get(). + * + * Returns: + * Zero on success or a negative error code on failure. + */ +static int drm_vblank_get(struct drm_device *dev, unsigned int pipe) +{ + struct drm_vblank_crtc *vblank = &dev->vblank[pipe]; + unsigned long irqflags; + int ret = 0; + + if (!dev->num_crtcs) + return -EINVAL; + + if (WARN_ON(pipe >= dev->num_crtcs)) + return -EINVAL; + + spin_lock_irqsave(&dev->vbl_lock, irqflags); + /* Going from 0->1 means we have to enable interrupts again */ + if (atomic_add_return(1, &vblank->refcount) == 1) { + ret = drm_vblank_enable(dev, pipe); + } else { + if (!vblank->enabled) { + atomic_dec(&vblank->refcount); + ret = -EINVAL; + } + } + spin_unlock_irqrestore(&dev->vbl_lock, irqflags); + + return ret; +} + +/** + * drm_crtc_vblank_get - get a reference count on vblank events + * @crtc: which CRTC to own + * + * Acquire a reference count on vblank events to avoid having them disabled + * while in use. + * + * Returns: + * Zero on success or a negative error code on failure. + */ +int drm_crtc_vblank_get(struct drm_crtc *crtc) +{ + return drm_vblank_get(crtc->dev, drm_crtc_index(crtc)); +} +EXPORT_SYMBOL(drm_crtc_vblank_get); + +/** + * drm_vblank_put - release ownership of vblank events + * @dev: DRM device + * @pipe: index of CRTC to release + * + * Release ownership of a given vblank counter, turning off interrupts + * if possible. Disable interrupts after drm_vblank_offdelay milliseconds. + * + * This is the legacy version of drm_crtc_vblank_put(). + */ +static void drm_vblank_put(struct drm_device *dev, unsigned int pipe) +{ + struct drm_vblank_crtc *vblank = &dev->vblank[pipe]; + + if (WARN_ON(pipe >= dev->num_crtcs)) + return; + + if (WARN_ON(atomic_read(&vblank->refcount) == 0)) + return; + + /* Last user schedules interrupt disable */ + if (atomic_dec_and_test(&vblank->refcount)) { + if (drm_vblank_offdelay == 0) + return; + else if (drm_vblank_offdelay < 0) + vblank_disable_fn((unsigned long)vblank); + else if (!dev->vblank_disable_immediate) + mod_timer(&vblank->disable_timer, + jiffies + ((drm_vblank_offdelay * HZ)/1000)); + } +} + +/** + * drm_crtc_vblank_put - give up ownership of vblank events + * @crtc: which counter to give up + * + * Release ownership of a given vblank counter, turning off interrupts + * if possible. Disable interrupts after drm_vblank_offdelay milliseconds. + */ +void drm_crtc_vblank_put(struct drm_crtc *crtc) +{ + drm_vblank_put(crtc->dev, drm_crtc_index(crtc)); +} +EXPORT_SYMBOL(drm_crtc_vblank_put); + +/** + * drm_wait_one_vblank - wait for one vblank + * @dev: DRM device + * @pipe: CRTC index + * + * This waits for one vblank to pass on @pipe, using the irq driver interfaces. + * It is a failure to call this when the vblank irq for @pipe is disabled, e.g. + * due to lack of driver support or because the crtc is off. + */ +void drm_wait_one_vblank(struct drm_device *dev, unsigned int pipe) +{ + struct drm_vblank_crtc *vblank = &dev->vblank[pipe]; + int ret; + u32 last; + + if (WARN_ON(pipe >= dev->num_crtcs)) + return; + + ret = drm_vblank_get(dev, pipe); + if (WARN(ret, "vblank not available on crtc %i, ret=%i\n", pipe, ret)) + return; + + last = drm_vblank_count(dev, pipe); + + ret = wait_event_timeout(vblank->queue, + last != drm_vblank_count(dev, pipe), + msecs_to_jiffies(100)); + + WARN(ret == 0, "vblank wait timed out on crtc %i\n", pipe); + + drm_vblank_put(dev, pipe); +} +EXPORT_SYMBOL(drm_wait_one_vblank); + +/** + * drm_crtc_wait_one_vblank - wait for one vblank + * @crtc: DRM crtc + * + * This waits for one vblank to pass on @crtc, using the irq driver interfaces. + * It is a failure to call this when the vblank irq for @crtc is disabled, e.g. + * due to lack of driver support or because the crtc is off. + */ +void drm_crtc_wait_one_vblank(struct drm_crtc *crtc) +{ + drm_wait_one_vblank(crtc->dev, drm_crtc_index(crtc)); +} +EXPORT_SYMBOL(drm_crtc_wait_one_vblank); + +/** + * drm_crtc_vblank_off - disable vblank events on a CRTC + * @crtc: CRTC in question + * + * Drivers can use this function to shut down the vblank interrupt handling when + * disabling a crtc. This function ensures that the latest vblank frame count is + * stored so that drm_vblank_on can restore it again. + * + * Drivers must use this function when the hardware vblank counter can get + * reset, e.g. when suspending. + */ +void drm_crtc_vblank_off(struct drm_crtc *crtc) +{ + struct drm_device *dev = crtc->dev; + unsigned int pipe = drm_crtc_index(crtc); + struct drm_vblank_crtc *vblank = &dev->vblank[pipe]; + struct drm_pending_vblank_event *e, *t; + struct timeval now; + unsigned long irqflags; + unsigned int seq; + + if (WARN_ON(pipe >= dev->num_crtcs)) + return; + + spin_lock_irqsave(&dev->event_lock, irqflags); + + spin_lock(&dev->vbl_lock); + DRM_DEBUG_VBL("crtc %d, vblank enabled %d, inmodeset %d\n", + pipe, vblank->enabled, vblank->inmodeset); + + /* Avoid redundant vblank disables without previous + * drm_crtc_vblank_on(). */ + if (drm_core_check_feature(dev, DRIVER_ATOMIC) || !vblank->inmodeset) + drm_vblank_disable_and_save(dev, pipe); + + wake_up(&vblank->queue); + + /* + * Prevent subsequent drm_vblank_get() from re-enabling + * the vblank interrupt by bumping the refcount. + */ + if (!vblank->inmodeset) { + atomic_inc(&vblank->refcount); + vblank->inmodeset = 1; + } + spin_unlock(&dev->vbl_lock); + + /* Send any queued vblank events, lest the natives grow disquiet */ + seq = drm_vblank_count_and_time(dev, pipe, &now); + + list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) { + if (e->pipe != pipe) + continue; + DRM_DEBUG("Sending premature vblank event on disable: " + "wanted %u, current %u\n", + e->event.sequence, seq); + list_del(&e->base.link); + drm_vblank_put(dev, pipe); + send_vblank_event(dev, e, seq, &now); + } + spin_unlock_irqrestore(&dev->event_lock, irqflags); + + /* Will be reset by the modeset helpers when re-enabling the crtc by + * calling drm_calc_timestamping_constants(). */ + vblank->hwmode.crtc_clock = 0; +} +EXPORT_SYMBOL(drm_crtc_vblank_off); + +/** + * drm_crtc_vblank_reset - reset vblank state to off on a CRTC + * @crtc: CRTC in question + * + * Drivers can use this function to reset the vblank state to off at load time. + * Drivers should use this together with the drm_crtc_vblank_off() and + * drm_crtc_vblank_on() functions. The difference compared to + * drm_crtc_vblank_off() is that this function doesn't save the vblank counter + * and hence doesn't need to call any driver hooks. + */ +void drm_crtc_vblank_reset(struct drm_crtc *crtc) +{ + struct drm_device *dev = crtc->dev; + unsigned long irqflags; + unsigned int pipe = drm_crtc_index(crtc); + struct drm_vblank_crtc *vblank = &dev->vblank[pipe]; + + spin_lock_irqsave(&dev->vbl_lock, irqflags); + /* + * Prevent subsequent drm_vblank_get() from enabling the vblank + * interrupt by bumping the refcount. + */ + if (!vblank->inmodeset) { + atomic_inc(&vblank->refcount); + vblank->inmodeset = 1; + } + spin_unlock_irqrestore(&dev->vbl_lock, irqflags); + + WARN_ON(!list_empty(&dev->vblank_event_list)); +} +EXPORT_SYMBOL(drm_crtc_vblank_reset); + +/** + * drm_crtc_vblank_on - enable vblank events on a CRTC + * @crtc: CRTC in question + * + * This functions restores the vblank interrupt state captured with + * drm_crtc_vblank_off() again. Note that calls to drm_crtc_vblank_on() and + * drm_crtc_vblank_off() can be unbalanced and so can also be unconditionally called + * in driver load code to reflect the current hardware state of the crtc. + */ +void drm_crtc_vblank_on(struct drm_crtc *crtc) +{ + struct drm_device *dev = crtc->dev; + unsigned int pipe = drm_crtc_index(crtc); + struct drm_vblank_crtc *vblank = &dev->vblank[pipe]; + unsigned long irqflags; + + if (WARN_ON(pipe >= dev->num_crtcs)) + return; + + spin_lock_irqsave(&dev->vbl_lock, irqflags); + DRM_DEBUG_VBL("crtc %d, vblank enabled %d, inmodeset %d\n", + pipe, vblank->enabled, vblank->inmodeset); + + /* Drop our private "prevent drm_vblank_get" refcount */ + if (vblank->inmodeset) { + atomic_dec(&vblank->refcount); + vblank->inmodeset = 0; + } + + drm_reset_vblank_timestamp(dev, pipe); + + /* + * re-enable interrupts if there are users left, or the + * user wishes vblank interrupts to be enabled all the time. + */ + if (atomic_read(&vblank->refcount) != 0 || drm_vblank_offdelay == 0) + WARN_ON(drm_vblank_enable(dev, pipe)); + spin_unlock_irqrestore(&dev->vbl_lock, irqflags); +} +EXPORT_SYMBOL(drm_crtc_vblank_on); + +static void drm_legacy_vblank_pre_modeset(struct drm_device *dev, + unsigned int pipe) +{ + struct drm_vblank_crtc *vblank = &dev->vblank[pipe]; + + /* vblank is not initialized (IRQ not installed ?), or has been freed */ + if (!dev->num_crtcs) + return; + + if (WARN_ON(pipe >= dev->num_crtcs)) + return; + + /* + * To avoid all the problems that might happen if interrupts + * were enabled/disabled around or between these calls, we just + * have the kernel take a reference on the CRTC (just once though + * to avoid corrupting the count if multiple, mismatch calls occur), + * so that interrupts remain enabled in the interim. + */ + if (!vblank->inmodeset) { + vblank->inmodeset = 0x1; + if (drm_vblank_get(dev, pipe) == 0) + vblank->inmodeset |= 0x2; + } +} + +static void drm_legacy_vblank_post_modeset(struct drm_device *dev, + unsigned int pipe) +{ + struct drm_vblank_crtc *vblank = &dev->vblank[pipe]; + unsigned long irqflags; + + /* vblank is not initialized (IRQ not installed ?), or has been freed */ + if (!dev->num_crtcs) + return; + + if (WARN_ON(pipe >= dev->num_crtcs)) + return; + + if (vblank->inmodeset) { + spin_lock_irqsave(&dev->vbl_lock, irqflags); + drm_reset_vblank_timestamp(dev, pipe); + spin_unlock_irqrestore(&dev->vbl_lock, irqflags); + + if (vblank->inmodeset & 0x2) + drm_vblank_put(dev, pipe); + + vblank->inmodeset = 0; + } +} + +int drm_legacy_modeset_ctl(struct drm_device *dev, void *data, + struct drm_file *file_priv) +{ + struct drm_modeset_ctl *modeset = data; + unsigned int pipe; + + /* If drm_vblank_init() hasn't been called yet, just no-op */ + if (!dev->num_crtcs) + return 0; + + /* KMS drivers handle this internally */ + if (!drm_core_check_feature(dev, DRIVER_LEGACY)) + return 0; + + pipe = modeset->crtc; + if (pipe >= dev->num_crtcs) + return -EINVAL; + + switch (modeset->cmd) { + case _DRM_PRE_MODESET: + drm_legacy_vblank_pre_modeset(dev, pipe); + break; + case _DRM_POST_MODESET: + drm_legacy_vblank_post_modeset(dev, pipe); + break; + default: + return -EINVAL; + } + + return 0; +} + +static inline bool vblank_passed(u32 seq, u32 ref) +{ + return (seq - ref) <= (1 << 23); +} + +static int drm_queue_vblank_event(struct drm_device *dev, unsigned int pipe, + union drm_wait_vblank *vblwait, + struct drm_file *file_priv) +{ + struct drm_vblank_crtc *vblank = &dev->vblank[pipe]; + struct drm_pending_vblank_event *e; + struct timeval now; + unsigned long flags; + unsigned int seq; + int ret; + + e = kzalloc(sizeof(*e), GFP_KERNEL); + if (e == NULL) { + ret = -ENOMEM; + goto err_put; + } + + e->pipe = pipe; + e->event.base.type = DRM_EVENT_VBLANK; + e->event.base.length = sizeof(e->event); + e->event.user_data = vblwait->request.signal; + + spin_lock_irqsave(&dev->event_lock, flags); + + /* + * drm_crtc_vblank_off() might have been called after we called + * drm_vblank_get(). drm_crtc_vblank_off() holds event_lock around the + * vblank disable, so no need for further locking. The reference from + * drm_vblank_get() protects against vblank disable from another source. + */ + if (!READ_ONCE(vblank->enabled)) { + ret = -EINVAL; + goto err_unlock; + } + + ret = drm_event_reserve_init_locked(dev, file_priv, &e->base, + &e->event.base); + + if (ret) + goto err_unlock; + + seq = drm_vblank_count_and_time(dev, pipe, &now); + + DRM_DEBUG("event on vblank count %u, current %u, crtc %u\n", + vblwait->request.sequence, seq, pipe); + + trace_drm_vblank_event_queued(file_priv, pipe, + vblwait->request.sequence); + + e->event.sequence = vblwait->request.sequence; + if (vblank_passed(seq, vblwait->request.sequence)) { + drm_vblank_put(dev, pipe); + send_vblank_event(dev, e, seq, &now); + vblwait->reply.sequence = seq; + } else { + /* drm_handle_vblank_events will call drm_vblank_put */ + list_add_tail(&e->base.link, &dev->vblank_event_list); + vblwait->reply.sequence = vblwait->request.sequence; + } + + spin_unlock_irqrestore(&dev->event_lock, flags); + + return 0; + +err_unlock: + spin_unlock_irqrestore(&dev->event_lock, flags); + kfree(e); +err_put: + drm_vblank_put(dev, pipe); + return ret; +} + +static bool drm_wait_vblank_is_query(union drm_wait_vblank *vblwait) +{ + if (vblwait->request.sequence) + return false; + + return _DRM_VBLANK_RELATIVE == + (vblwait->request.type & (_DRM_VBLANK_TYPES_MASK | + _DRM_VBLANK_EVENT | + _DRM_VBLANK_NEXTONMISS)); +} + +/* + * Wait for VBLANK. + * + * \param inode device inode. + * \param file_priv DRM file private. + * \param cmd command. + * \param data user argument, pointing to a drm_wait_vblank structure. + * \return zero on success or a negative number on failure. + * + * This function enables the vblank interrupt on the pipe requested, then + * sleeps waiting for the requested sequence number to occur, and drops + * the vblank interrupt refcount afterwards. (vblank IRQ disable follows that + * after a timeout with no further vblank waits scheduled). + */ +int drm_wait_vblank(struct drm_device *dev, void *data, + struct drm_file *file_priv) +{ + struct drm_vblank_crtc *vblank; + union drm_wait_vblank *vblwait = data; + int ret; + unsigned int flags, seq, pipe, high_pipe; + + if (!dev->irq_enabled) + return -EINVAL; + + if (vblwait->request.type & _DRM_VBLANK_SIGNAL) + return -EINVAL; + + if (vblwait->request.type & + ~(_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK | + _DRM_VBLANK_HIGH_CRTC_MASK)) { + DRM_ERROR("Unsupported type value 0x%x, supported mask 0x%x\n", + vblwait->request.type, + (_DRM_VBLANK_TYPES_MASK | _DRM_VBLANK_FLAGS_MASK | + _DRM_VBLANK_HIGH_CRTC_MASK)); + return -EINVAL; + } + + flags = vblwait->request.type & _DRM_VBLANK_FLAGS_MASK; + high_pipe = (vblwait->request.type & _DRM_VBLANK_HIGH_CRTC_MASK); + if (high_pipe) + pipe = high_pipe >> _DRM_VBLANK_HIGH_CRTC_SHIFT; + else + pipe = flags & _DRM_VBLANK_SECONDARY ? 1 : 0; + if (pipe >= dev->num_crtcs) + return -EINVAL; + + vblank = &dev->vblank[pipe]; + + /* If the counter is currently enabled and accurate, short-circuit + * queries to return the cached timestamp of the last vblank. + */ + if (dev->vblank_disable_immediate && + drm_wait_vblank_is_query(vblwait) && + READ_ONCE(vblank->enabled)) { + struct timeval now; + + vblwait->reply.sequence = + drm_vblank_count_and_time(dev, pipe, &now); + vblwait->reply.tval_sec = now.tv_sec; + vblwait->reply.tval_usec = now.tv_usec; + return 0; + } + + ret = drm_vblank_get(dev, pipe); + if (ret) { + DRM_DEBUG("crtc %d failed to acquire vblank counter, %d\n", pipe, ret); + return ret; + } + seq = drm_vblank_count(dev, pipe); + + switch (vblwait->request.type & _DRM_VBLANK_TYPES_MASK) { + case _DRM_VBLANK_RELATIVE: + vblwait->request.sequence += seq; + vblwait->request.type &= ~_DRM_VBLANK_RELATIVE; + case _DRM_VBLANK_ABSOLUTE: + break; + default: + ret = -EINVAL; + goto done; + } + + if ((flags & _DRM_VBLANK_NEXTONMISS) && + vblank_passed(seq, vblwait->request.sequence)) + vblwait->request.sequence = seq + 1; + + if (flags & _DRM_VBLANK_EVENT) { + /* must hold on to the vblank ref until the event fires + * drm_vblank_put will be called asynchronously + */ + return drm_queue_vblank_event(dev, pipe, vblwait, file_priv); + } + + if (vblwait->request.sequence != seq) { + DRM_DEBUG("waiting on vblank count %u, crtc %u\n", + vblwait->request.sequence, pipe); + DRM_WAIT_ON(ret, vblank->queue, 3 * HZ, + vblank_passed(drm_vblank_count(dev, pipe), + vblwait->request.sequence) || + !READ_ONCE(vblank->enabled)); + } + + if (ret != -EINTR) { + struct timeval now; + + vblwait->reply.sequence = drm_vblank_count_and_time(dev, pipe, &now); + vblwait->reply.tval_sec = now.tv_sec; + vblwait->reply.tval_usec = now.tv_usec; + + DRM_DEBUG("crtc %d returning %u to client\n", + pipe, vblwait->reply.sequence); + } else { + DRM_DEBUG("crtc %d vblank wait interrupted by signal\n", pipe); + } + +done: + drm_vblank_put(dev, pipe); + return ret; +} + +static void drm_handle_vblank_events(struct drm_device *dev, unsigned int pipe) +{ + struct drm_pending_vblank_event *e, *t; + struct timeval now; + unsigned int seq; + + assert_spin_locked(&dev->event_lock); + + seq = drm_vblank_count_and_time(dev, pipe, &now); + + list_for_each_entry_safe(e, t, &dev->vblank_event_list, base.link) { + if (e->pipe != pipe) + continue; + if (!vblank_passed(seq, e->event.sequence)) + continue; + + DRM_DEBUG("vblank event on %u, current %u\n", + e->event.sequence, seq); + + list_del(&e->base.link); + drm_vblank_put(dev, pipe); + send_vblank_event(dev, e, seq, &now); + } + + trace_drm_vblank_event(pipe, seq); +} + +/** + * drm_handle_vblank - handle a vblank event + * @dev: DRM device + * @pipe: index of CRTC where this event occurred + * + * Drivers should call this routine in their vblank interrupt handlers to + * update the vblank counter and send any signals that may be pending. + * + * This is the legacy version of drm_crtc_handle_vblank(). + */ +bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe) +{ + struct drm_vblank_crtc *vblank = &dev->vblank[pipe]; + unsigned long irqflags; + bool disable_irq; + + if (WARN_ON_ONCE(!dev->num_crtcs)) + return false; + + if (WARN_ON(pipe >= dev->num_crtcs)) + return false; + + spin_lock_irqsave(&dev->event_lock, irqflags); + + /* Need timestamp lock to prevent concurrent execution with + * vblank enable/disable, as this would cause inconsistent + * or corrupted timestamps and vblank counts. + */ + spin_lock(&dev->vblank_time_lock); + + /* Vblank irq handling disabled. Nothing to do. */ + if (!vblank->enabled) { + spin_unlock(&dev->vblank_time_lock); + spin_unlock_irqrestore(&dev->event_lock, irqflags); + return false; + } + + drm_update_vblank_count(dev, pipe, true); + + spin_unlock(&dev->vblank_time_lock); + + wake_up(&vblank->queue); + + /* With instant-off, we defer disabling the interrupt until after + * we finish processing the following vblank after all events have + * been signaled. The disable has to be last (after + * drm_handle_vblank_events) so that the timestamp is always accurate. + */ + disable_irq = (dev->vblank_disable_immediate && + drm_vblank_offdelay > 0 && + !atomic_read(&vblank->refcount)); + + drm_handle_vblank_events(dev, pipe); + + spin_unlock_irqrestore(&dev->event_lock, irqflags); + + if (disable_irq) + vblank_disable_fn((unsigned long)vblank); + + return true; +} +EXPORT_SYMBOL(drm_handle_vblank); + +/** + * drm_crtc_handle_vblank - handle a vblank event + * @crtc: where this event occurred + * + * Drivers should call this routine in their vblank interrupt handlers to + * update the vblank counter and send any signals that may be pending. + * + * This is the native KMS version of drm_handle_vblank(). + * + * Returns: + * True if the event was successfully handled, false on failure. + */ +bool drm_crtc_handle_vblank(struct drm_crtc *crtc) +{ + return drm_handle_vblank(crtc->dev, drm_crtc_index(crtc)); +} +EXPORT_SYMBOL(drm_crtc_handle_vblank); |
