Module Name: src
Committed By: riastradh
Date: Mon Aug 27 14:42:43 UTC 2018
Modified Files:
src/sys/external/bsd/drm2/dist/drm: drm_irq.c
src/sys/external/bsd/drm2/dist/include/drm: drmP.h
Log Message:
Rework vblank locking. New drm_vblank_get/put_locked subroutines.
To generate a diff of this commit:
cvs rdiff -u -r1.12 -r1.13 src/sys/external/bsd/drm2/dist/drm/drm_irq.c
cvs rdiff -u -r1.25 -r1.26 src/sys/external/bsd/drm2/dist/include/drm/drmP.h
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/external/bsd/drm2/dist/drm/drm_irq.c
diff -u src/sys/external/bsd/drm2/dist/drm/drm_irq.c:1.12 src/sys/external/bsd/drm2/dist/drm/drm_irq.c:1.13
--- src/sys/external/bsd/drm2/dist/drm/drm_irq.c:1.12 Mon Aug 27 07:03:39 2018
+++ src/sys/external/bsd/drm2/dist/drm/drm_irq.c Mon Aug 27 14:42:43 2018
@@ -1,4 +1,4 @@
-/* $NetBSD: drm_irq.c,v 1.12 2018/08/27 07:03:39 riastradh Exp $ */
+/* $NetBSD: drm_irq.c,v 1.13 2018/08/27 14:42:43 riastradh Exp $ */
/*
* drm_irq.c IRQ and vblank support
@@ -35,7 +35,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: drm_irq.c,v 1.12 2018/08/27 07:03:39 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: drm_irq.c,v 1.13 2018/08/27 14:42:43 riastradh Exp $");
#include <drm/drmP.h>
#include "drm_trace.h"
@@ -62,6 +62,10 @@ __KERNEL_RCSID(0, "$NetBSD: drm_irq.c,v
#include <sys/select.h>
#endif
+/*
+ * Lock order: dev->event_lock, then dev->vbl_lock, then dev->vblank_time_lock
+ */
+
/* Access macro for slots in vblank timestamp ringbuffer. */
#define vblanktimestamp(dev, pipe, count) \
((dev)->vblank[pipe].time[(count) % DRM_VBLANKTIME_RBSIZE])
@@ -144,6 +148,8 @@ static void drm_reset_vblank_timestamp(s
struct timeval t_vblank;
int count = DRM_TIMESTAMP_MAXRETRIES;
+ assert_spin_locked(&dev->vbl_lock);
+
spin_lock(&dev->vblank_time_lock);
/*
@@ -198,6 +204,8 @@ static void drm_update_vblank_count(stru
int count = DRM_TIMESTAMP_MAXRETRIES;
int framedur_ns = vblank->framedur_ns;
+ assert_spin_locked(&dev->vbl_lock);
+
/*
* Interrupts were disabled prior to this call, so deal with counter
* wrap if needed.
@@ -331,6 +339,8 @@ static void vblank_disable_and_save(stru
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.
@@ -358,6 +368,23 @@ static void vblank_disable_and_save(stru
spin_unlock_irqrestore(&dev->vblank_time_lock, irqflags);
}
+static void
+vblank_disable_locked(struct drm_vblank_crtc *vblank, struct drm_device *dev,
+ unsigned int pipe)
+{
+
+ BUG_ON(vblank != &dev->vblank[pipe]);
+ assert_spin_locked(&dev->vbl_lock);
+
+ if (!dev->vblank_disable_allowed)
+ return;
+
+ if (atomic_read(&vblank->refcount) == 0 && vblank->enabled) {
+ DRM_DEBUG("disabling vblank on crtc %u\n", pipe);
+ vblank_disable_and_save(dev, pipe);
+ }
+}
+
static void vblank_disable_fn(unsigned long arg)
{
struct drm_vblank_crtc *vblank = (void *)arg;
@@ -1269,31 +1296,24 @@ static int drm_vblank_enable(struct drm_
}
/**
- * drm_vblank_get - get a reference count on vblank events
+ * drm_vblank_get_locked - like drm_vblank_get but caller holds lock
* @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.
*/
-int drm_vblank_get(struct drm_device *dev, unsigned int pipe)
+int
+drm_vblank_get_locked(struct drm_device *dev, unsigned int pipe)
{
struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
- unsigned long irqflags;
int ret = 0;
+ assert_spin_locked(&dev->vbl_lock);
+
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);
@@ -1303,6 +1323,30 @@ int drm_vblank_get(struct drm_device *de
ret = -EINVAL;
}
}
+
+ 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.
+ */
+int drm_vblank_get(struct drm_device *dev, unsigned int pipe)
+{
+ unsigned long irqflags;
+ int ret;
+
+ spin_lock_irqsave(&dev->vbl_lock, irqflags);
+ ret = drm_vblank_get_locked(dev, pipe);
spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
return ret;
@@ -1310,6 +1354,16 @@ int drm_vblank_get(struct drm_device *de
EXPORT_SYMBOL(drm_vblank_get);
/**
+ * drm_crtc_vblank_get_locked - like drm_crtc_vblank_get but caller holds lock
+ * @crtc: which CRTC to own
+ */
+int
+drm_crtc_vblank_get_locked(struct drm_crtc *crtc)
+{
+ return drm_vblank_get_locked(crtc->dev, drm_crtc_index(crtc));
+}
+
+/**
* drm_crtc_vblank_get - get a reference count on vblank events
* @crtc: which CRTC to own
*
@@ -1328,6 +1382,36 @@ int drm_crtc_vblank_get(struct drm_crtc
EXPORT_SYMBOL(drm_crtc_vblank_get);
/**
+ * drm_vblank_put_locked - like drm_vblank_put but caller holds lock
+ * @dev: DRM device
+ * @pipe: index of CRTC to release
+ */
+void
+drm_vblank_put_locked(struct drm_device *dev, unsigned int pipe)
+{
+ struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
+
+ assert_spin_locked(&dev->vbl_lock);
+
+ 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_locked(vblank, dev, pipe);
+ else if (!dev->vblank_disable_immediate)
+ mod_timer(&vblank->disable_timer,
+ jiffies + ((drm_vblank_offdelay * HZ)/1000));
+ }
+}
+
+/**
* drm_vblank_put - release ownership of vblank events
* @dev: DRM device
* @pipe: index of CRTC to release
@@ -1361,6 +1445,16 @@ void drm_vblank_put(struct drm_device *d
EXPORT_SYMBOL(drm_vblank_put);
/**
+ * drm_crtc_vblank_put_locked - like drm_crtc_vblank_put but caller holds lock
+ * @crtc: which counter to give up
+ */
+void
+drm_crtc_vblank_put_locked(struct drm_crtc *crtc)
+{
+ drm_vblank_put_locked(crtc->dev, drm_crtc_index(crtc));
+}
+
+/**
* drm_crtc_vblank_put - give up ownership of vblank events
* @crtc: which counter to give up
*
@@ -1990,9 +2084,6 @@ bool drm_handle_vblank(struct drm_device
{
struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
unsigned long irqflags;
-#ifdef __NetBSD__ /* XXX vblank locking */
- unsigned long irqflags_vbl_lock;
-#endif
if (WARN_ON_ONCE(!dev->num_crtcs))
return false;
@@ -2001,9 +2092,6 @@ bool drm_handle_vblank(struct drm_device
return false;
spin_lock_irqsave(&dev->event_lock, irqflags);
-#ifdef __NetBSD__ /* XXX vblank locking */
- spin_lock_irqsave(&dev->vbl_lock, irqflags_vbl_lock);
-#endif
/* Need timestamp lock to prevent concurrent execution with
* vblank enable/disable, as this would cause inconsistent
@@ -2015,9 +2103,6 @@ bool drm_handle_vblank(struct drm_device
if (!vblank->enabled) {
spin_unlock(&dev->vblank_time_lock);
spin_unlock_irqrestore(&dev->event_lock, irqflags);
-#ifdef __NetBSD__ /* XXX vblank locking */
- spin_unlock_irqrestore(&dev->vbl_lock, irqflags_vbl_lock);
-#endif
return false;
}
@@ -2026,7 +2111,9 @@ bool drm_handle_vblank(struct drm_device
spin_unlock(&dev->vblank_time_lock);
#ifdef __NetBSD__
+ spin_lock(&dev->vbl_lock);
DRM_SPIN_WAKEUP_ONE(&vblank->queue, &dev->vbl_lock);
+ spin_unlock(&dev->vbl_lock);
#else
wake_up(&vblank->queue);
#endif
@@ -2043,9 +2130,6 @@ bool drm_handle_vblank(struct drm_device
vblank_disable_fn((unsigned long)vblank);
spin_unlock_irqrestore(&dev->event_lock, irqflags);
-#ifdef __NetBSD__ /* XXX vblank locking */
- spin_unlock_irqrestore(&dev->vbl_lock, irqflags_vbl_lock);
-#endif
return true;
}
Index: src/sys/external/bsd/drm2/dist/include/drm/drmP.h
diff -u src/sys/external/bsd/drm2/dist/include/drm/drmP.h:1.25 src/sys/external/bsd/drm2/dist/include/drm/drmP.h:1.26
--- src/sys/external/bsd/drm2/dist/include/drm/drmP.h:1.25 Mon Aug 27 13:42:47 2018
+++ src/sys/external/bsd/drm2/dist/include/drm/drmP.h Mon Aug 27 14:42:43 2018
@@ -1,4 +1,4 @@
-/* $NetBSD: drmP.h,v 1.25 2018/08/27 13:42:47 riastradh Exp $ */
+/* $NetBSD: drmP.h,v 1.26 2018/08/27 14:42:43 riastradh Exp $ */
/*
* Internal Header for the Direct Rendering Manager
@@ -1071,6 +1071,10 @@ extern int drm_vblank_get(struct drm_dev
extern void drm_vblank_put(struct drm_device *dev, unsigned int pipe);
extern int drm_crtc_vblank_get(struct drm_crtc *crtc);
extern void drm_crtc_vblank_put(struct drm_crtc *crtc);
+extern int drm_vblank_get_locked(struct drm_device *dev, unsigned int pipe);
+extern void drm_vblank_put_locked(struct drm_device *dev, unsigned int pipe);
+extern int drm_crtc_vblank_get_locked(struct drm_crtc *crtc);
+extern void drm_crtc_vblank_put_locked(struct drm_crtc *crtc);
extern void drm_wait_one_vblank(struct drm_device *dev, unsigned int pipe);
extern void drm_crtc_wait_one_vblank(struct drm_crtc *crtc);
extern void drm_vblank_off(struct drm_device *dev, unsigned int pipe);
