drm: Extract&Document drm_irq.h

The drm_irq docs want one function from drmP.h, but that one is a
serious mess. Extract it, and while at it improve the docs a bit.
There's a bit a header loop issue since core data structures like
drm_device and drm_driver aren't in their own headers yet, which means
the drm_irq.h include in drmP.h needs to be in just the right spot :(

Also noticed that drm_vblank_crtc->last_wait is entirely unused,
remove it.

v2: git add drm_irq.h ...

Acked-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>

4 files changed, 188 insertions, 83 deletions

diff --git a/Documentation/gpu/drm-kms.rst b/Documentation/gpu/drm-kms.rst
index 675221f0a64b..8dfa4b214b96 100644
--- a/Documentation/gpu/drm-kms.rst
+++ b/Documentation/gpu/drm-kms.rst
@@ -649,5 +649,5 @@ Vertical Blanking and Interrupt Handling Functions Reference
 .. kernel-doc:: drivers/gpu/drm/drm_irq.c
    :export:
 
-.. kernel-doc:: include/drm/drmP.h
-   :functions: drm_crtc_vblank_waitqueue
+.. kernel-doc:: include/drm/drm_irq.h
+   :internal:
diff --git a/drivers/gpu/drm/drm_irq.c b/drivers/gpu/drm/drm_irq.c
index 35c86acede38..77f357b2c386 100644
--- a/drivers/gpu/drm/drm_irq.c
+++ b/drivers/gpu/drm/drm_irq.c
@@ -1695,7 +1695,6 @@ int drm_wait_vblank(struct drm_device *dev, void *data,
 
         DRM_DEBUG("waiting on vblank count %d, crtc %u\n",
                   vblwait->request.sequence, pipe);
-        vblank->last_wait = vblwait->request.sequence;
         DRM_WAIT_ON(ret, vblank->queue, 3 * HZ,
                     (((drm_vblank_count(dev, pipe) -
                        vblwait->request.sequence) <= (1 << 23)) ||
diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index c2fe2cffb809..d3778652e462 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -52,7 +52,6 @@
 #include <linux/poll.h>
 #include <linux/ratelimit.h>
 #include <linux/sched.h>
-#include <linux/seqlock.h>
 #include <linux/slab.h>
 #include <linux/types.h>
 #include <linux/vmalloc.h>
@@ -87,6 +86,7 @@ struct drm_device_dma;
 struct drm_dma_handle;
 struct drm_gem_object;
 struct drm_master;
+struct drm_vblank_crtc;
 
 struct device_node;
 struct videomode;
@@ -684,35 +684,6 @@ struct drm_minor {
         struct mutex debugfs_lock; /* Protects debugfs_list. */
 };
 
-
-struct drm_pending_vblank_event {
-        struct drm_pending_event base;
-        unsigned int pipe;
-        struct drm_event_vblank event;
-};
-
-struct drm_vblank_crtc {
-        struct drm_device *dev;         /* pointer to the drm_device */
-        wait_queue_head_t queue;        /**< VBLANK wait queue */
-        struct timer_list disable_timer;                /* delayed disable timer */
-
-        seqlock_t seqlock;              /* protects vblank count and time */
-
-        u32 count;                      /* vblank counter */
-        struct timeval time;            /* vblank timestamp */
-
-        atomic_t refcount;              /* number of users of vblank interruptsper crtc */
-        u32 last;                       /* protected by dev->vbl_lock, used */
-                                        /* for wraparound handling */
-        u32 last_wait;                  /* Last vblank seqno waited per CRTC */
-        unsigned int inmodeset;         /* Display driver is setting mode */
-        unsigned int pipe;              /* crtc index */
-        int framedur_ns;                /* frame/field duration in ns */
-        int linedur_ns;                 /* line duration in ns */
-        bool enabled;                   /* so we don't call enable more than
-                                           once per disable */
-};
-
 /**
  * DRM device structure. This structure represent a complete card that
  * may contain multiple heads.
@@ -847,6 +818,8 @@ struct drm_device {
         int switch_power_state;
 };
 
+#include <drm/drm_irq.h>
+
 #define DRM_SWITCH_POWER_ON 0
 #define DRM_SWITCH_POWER_OFF 1
 #define DRM_SWITCH_POWER_CHANGING 2
@@ -933,56 +906,6 @@ void drm_clflush_virt_range(void *addr, unsigned long length);
  * DMA quiscent + idle. DMA quiescent usually requires the hardware lock.
  */
 
-                                /* IRQ support (drm_irq.h) */
-extern int drm_irq_install(struct drm_device *dev, int irq);
-extern int drm_irq_uninstall(struct drm_device *dev);
-
-extern int drm_vblank_init(struct drm_device *dev, unsigned int num_crtcs);
-extern int drm_wait_vblank(struct drm_device *dev, void *data,
-                           struct drm_file *filp);
-extern u32 drm_vblank_count(struct drm_device *dev, unsigned int pipe);
-extern u32 drm_crtc_vblank_count(struct drm_crtc *crtc);
-extern u32 drm_crtc_vblank_count_and_time(struct drm_crtc *crtc,
-                                          struct timeval *vblanktime);
-extern void drm_crtc_send_vblank_event(struct drm_crtc *crtc,
-                                       struct drm_pending_vblank_event *e);
-extern void drm_crtc_arm_vblank_event(struct drm_crtc *crtc,
-                                      struct drm_pending_vblank_event *e);
-extern bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe);
-extern bool drm_crtc_handle_vblank(struct drm_crtc *crtc);
-extern int drm_crtc_vblank_get(struct drm_crtc *crtc);
-extern void drm_crtc_vblank_put(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);
-extern void drm_vblank_on(struct drm_device *dev, unsigned int pipe);
-extern void drm_crtc_vblank_off(struct drm_crtc *crtc);
-extern void drm_crtc_vblank_reset(struct drm_crtc *crtc);
-extern void drm_crtc_vblank_on(struct drm_crtc *crtc);
-extern void drm_vblank_cleanup(struct drm_device *dev);
-extern u32 drm_accurate_vblank_count(struct drm_crtc *crtc);
-extern u32 drm_vblank_no_hw_counter(struct drm_device *dev, unsigned int pipe);
-
-extern int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev,
-                                                 unsigned int pipe, int *max_error,
-                                                 struct timeval *vblank_time,
-                                                 unsigned flags,
-                                                 const struct drm_display_mode *mode);
-extern void drm_calc_timestamping_constants(struct drm_crtc *crtc,
-                                            const struct drm_display_mode *mode);
-
-/**
- * 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() & co.
- */
-static inline wait_queue_head_t *drm_crtc_vblank_waitqueue(struct drm_crtc *crtc)
-{
-        return &crtc->dev->vblank[drm_crtc_index(crtc)].queue;
-}
-
 /* Modesetting support */
 extern void drm_vblank_pre_modeset(struct drm_device *dev, unsigned int pipe);
 extern void drm_vblank_post_modeset(struct drm_device *dev, unsigned int pipe);
diff --git a/include/drm/drm_irq.h b/include/drm/drm_irq.h
new file mode 100644
index 000000000000..2401b14d301f
--- /dev/null
+++ b/include/drm/drm_irq.h
@@ -0,0 +1,183 @@
+/*
+ * Copyright 2016 Intel Corp.
+ *
+ * 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.
+ */
+
+#ifndef _DRM_IRQ_H_
+#define _DRM_IRQ_H_
+
+#include <linux/seqlock.h>
+
+/**
+ * struct drm_pending_vblank_event - pending vblank event tracking
+ */
+struct drm_pending_vblank_event {
+        /**
+         * @base: Base structure for tracking pending DRM events.
+         */
+        struct drm_pending_event base;
+        /**
+         * @pipe: drm_crtc_index() of the &drm_crtc this event is for.
+         */
+        unsigned int pipe;
+        /**
+         * @event: Actual event which will be sent to userspace.
+         */
+        struct drm_event_vblank event;
+};
+
+/**
+ * struct drm_vblank_crtc - vblank tracking for a CRTC
+ *
+ * This structure tracks the vblank state for one CRTC.
+ *
+ * Note that for historical reasons - the vblank handling code is still shared
+ * with legacy/non-kms drivers - this is a free-standing structure not directly
+ * connected to struct &drm_crtc. But all public interface functions are taking
+ * a struct &drm_crtc to hide this implementation detail.
+ */
+struct drm_vblank_crtc {
+        /**
+         * @dev: Pointer to the &drm_device.
+         */
+        struct drm_device *dev;
+        /**
+         * @queue: Wait queue for vblank waiters.
+         */
+        wait_queue_head_t queue;        /**< VBLANK wait queue */
+        /**
+         * @disable_timer: Disable timer for the delayed vblank disabling
+         * hysteresis logic. Vblank disabling is controlled through the
+         * drm_vblank_offdelay module option and the setting of the
+         * max_vblank_count value in the &drm_device structure.
+         */
+        struct timer_list disable_timer;
+
+        /**
+         * @seqlock: Protect vblank count and time.
+         */
+        seqlock_t seqlock;              /* protects vblank count and time */
+
+        /**
+         * @count: Current software vblank counter.
+         */
+        u32 count;
+        /**
+         * @time: Vblank timestamp corresponding to @count.
+         */
+        struct timeval time;
+
+        /**
+         * @refcount: Number of users/waiters of the vblank interrupt. Only when
+         * this refcount reaches 0 can the hardware interrupt be disabled using
+         * @disable_timer.
+         */
+        atomic_t refcount;              /* number of users of vblank interruptsper crtc */
+        /**
+         * @last: Protected by dev->vbl_lock, used for wraparound handling.
+         */
+        u32 last;
+        /**
+         * @inmodeset: Tracks whether the vblank is disabled due to a modeset.
+         * For legacy driver bit 2 additionally tracks whether an additional
+         * temporary vblank reference has been acquired to paper over the
+         * hardware counter resetting/jumping. KMS drivers should instead just
+         * call drm_crtc_vblank_off() and drm_crtc_vblank_on(), which explicitly
+         * save and restore the vblank count.
+         */
+        unsigned int inmodeset;         /* Display driver is setting mode */
+        /**
+         * @pipe: drm_crtc_index() of the &drm_crtc corresponding to this
+         * structure.
+         */
+        unsigned int pipe;
+        /**
+         * @framedur_ns: Frame/Field duration in ns, used by
+         * drm_calc_vbltimestamp_from_scanoutpos() and computed by
+         * drm_calc_timestamping_constants().
+         */
+        int framedur_ns;
+        /**
+         * @linedur_ns: Line duration in ns, used by
+         * drm_calc_vbltimestamp_from_scanoutpos() and computed by
+         * drm_calc_timestamping_constants().
+         */
+        int linedur_ns;
+        /**
+         * @enabled: Tracks the enabling state of the corresponding &drm_crtc to
+         * avoid double-disabling and hence corrupting saved state. Needed by
+         * drivers not using atomic KMS, since those might go through their CRTC
+         * disabling functions multiple times.
+         */
+        bool enabled;
+};
+
+extern int drm_irq_install(struct drm_device *dev, int irq);
+extern int drm_irq_uninstall(struct drm_device *dev);
+
+extern int drm_vblank_init(struct drm_device *dev, unsigned int num_crtcs);
+extern int drm_wait_vblank(struct drm_device *dev, void *data,
+                           struct drm_file *filp);
+extern u32 drm_vblank_count(struct drm_device *dev, unsigned int pipe);
+extern u32 drm_crtc_vblank_count(struct drm_crtc *crtc);
+extern u32 drm_crtc_vblank_count_and_time(struct drm_crtc *crtc,
+                                          struct timeval *vblanktime);
+extern void drm_crtc_send_vblank_event(struct drm_crtc *crtc,
+                                       struct drm_pending_vblank_event *e);
+extern void drm_crtc_arm_vblank_event(struct drm_crtc *crtc,
+                                      struct drm_pending_vblank_event *e);
+extern bool drm_handle_vblank(struct drm_device *dev, unsigned int pipe);
+extern bool drm_crtc_handle_vblank(struct drm_crtc *crtc);
+extern int drm_crtc_vblank_get(struct drm_crtc *crtc);
+extern void drm_crtc_vblank_put(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);
+extern void drm_vblank_on(struct drm_device *dev, unsigned int pipe);
+extern void drm_crtc_vblank_off(struct drm_crtc *crtc);
+extern void drm_crtc_vblank_reset(struct drm_crtc *crtc);
+extern void drm_crtc_vblank_on(struct drm_crtc *crtc);
+extern void drm_vblank_cleanup(struct drm_device *dev);
+extern u32 drm_accurate_vblank_count(struct drm_crtc *crtc);
+extern u32 drm_vblank_no_hw_counter(struct drm_device *dev, unsigned int pipe);
+
+extern int drm_calc_vbltimestamp_from_scanoutpos(struct drm_device *dev,
+                                                 unsigned int pipe, int *max_error,
+                                                 struct timeval *vblank_time,
+                                                 unsigned flags,
+                                                 const struct drm_display_mode *mode);
+extern void drm_calc_timestamping_constants(struct drm_crtc *crtc,
+                                            const struct drm_display_mode *mode);
+
+/**
+ * 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.
+ */
+static inline wait_queue_head_t *drm_crtc_vblank_waitqueue(struct drm_crtc *crtc)
+{
+        return &crtc->dev->vblank[drm_crtc_index(crtc)].queue;
+}
+
+#endif