drm: i915: Add ioctl for scheduling buffer swaps at vertical blanks.

This uses the core facility to schedule a driver callback that will be called
ASAP after the given vertical blank interrupt with the HW lock held.

Signed-off-by: Dave Airlie <airlied@linux.ie>

4 files changed, 211 insertions, 0 deletions

diff --git a/drivers/char/drm/i915_dma.c b/drivers/char/drm/i915_dma.c
index fb7913ff5286..9354ce3b0093 100644
--- a/drivers/char/drm/i915_dma.c
+++ b/drivers/char/drm/i915_dma.c
@@ -162,6 +162,7 @@ static int i915_initialize(drm_device_t * dev,
 
         dev_priv->ring.virtual_start = dev_priv->ring.map.handle;
 
+        dev_priv->cpp = init->cpp;
         dev_priv->back_offset = init->back_offset;
         dev_priv->front_offset = init->front_offset;
         dev_priv->current_page = 0;
@@ -782,6 +783,7 @@ drm_ioctl_desc_t i915_ioctls[] = {
         [DRM_IOCTL_NR(DRM_I915_DESTROY_HEAP)] = { i915_mem_destroy_heap, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY },
         [DRM_IOCTL_NR(DRM_I915_SET_VBLANK_PIPE)] = { i915_vblank_pipe_set, DRM_AUTH|DRM_MASTER|DRM_ROOT_ONLY },
         [DRM_IOCTL_NR(DRM_I915_GET_VBLANK_PIPE)] = { i915_vblank_pipe_get, DRM_AUTH },
+        [DRM_IOCTL_NR(DRM_I915_VBLANK_SWAP)] = {i915_vblank_swap, DRM_AUTH},
 };
 
 int i915_max_ioctl = DRM_ARRAY_SIZE(i915_ioctls);
diff --git a/drivers/char/drm/i915_drm.h b/drivers/char/drm/i915_drm.h
index 6af83e613f27..8926beb5a61f 100644
--- a/drivers/char/drm/i915_drm.h
+++ b/drivers/char/drm/i915_drm.h
@@ -132,6 +132,7 @@ typedef struct _drm_i915_sarea {
 #define DRM_I915_DESTROY_HEAP   0x0c
 #define DRM_I915_SET_VBLANK_PIPE        0x0d
 #define DRM_I915_GET_VBLANK_PIPE        0x0e
+#define DRM_I915_VBLANK_SWAP    0x0f
 
 #define DRM_IOCTL_I915_INIT             DRM_IOW( DRM_COMMAND_BASE + DRM_I915_INIT, drm_i915_init_t)
 #define DRM_IOCTL_I915_FLUSH            DRM_IO ( DRM_COMMAND_BASE + DRM_I915_FLUSH)
@@ -243,4 +244,12 @@ typedef struct drm_i915_vblank_pipe {
         int pipe;
 } drm_i915_vblank_pipe_t;
 
+/* Schedule buffer swap at given vertical blank:
+ */
+typedef struct drm_i915_vblank_swap {
+        drm_drawable_t drawable;
+        unsigned int pipe;
+        unsigned int sequence;
+} drm_i915_vblank_swap_t;
+
 #endif                          /* _I915_DRM_H_ */
diff --git a/drivers/char/drm/i915_drv.h b/drivers/char/drm/i915_drv.h
index 5f0c4fa04da2..334b0ce8181d 100644
--- a/drivers/char/drm/i915_drv.h
+++ b/drivers/char/drm/i915_drv.h
@@ -71,6 +71,13 @@ struct mem_block {
         DRMFILE filp;           /* 0: free, -1: heap, other: real files */
 };
 
+typedef struct _drm_i915_vbl_swap {
+        struct list_head head;
+        drm_drawable_t drw_id;
+        unsigned int pipe;
+        unsigned int sequence;
+} drm_i915_vbl_swap_t;
+
 typedef struct drm_i915_private {
         drm_local_map_t *sarea;
         drm_local_map_t *mmio_map;
@@ -83,6 +90,7 @@ typedef struct drm_i915_private {
         dma_addr_t dma_status_page;
         unsigned long counter;
 
+        unsigned int cpp;
         int back_offset;
         int front_offset;
         int current_page;
@@ -98,6 +106,10 @@ typedef struct drm_i915_private {
         struct mem_block *agp_heap;
         unsigned int sr01, adpa, ppcr, dvob, dvoc, lvds;
         int vblank_pipe;
+
+        spinlock_t swaps_lock;
+        drm_i915_vbl_swap_t vbl_swaps;
+        unsigned int swaps_pending;
 } drm_i915_private_t;
 
 extern drm_ioctl_desc_t i915_ioctls[];
@@ -124,6 +136,7 @@ extern void i915_driver_irq_postinstall(drm_device_t * dev);
 extern void i915_driver_irq_uninstall(drm_device_t * dev);
 extern int i915_vblank_pipe_set(DRM_IOCTL_ARGS);
 extern int i915_vblank_pipe_get(DRM_IOCTL_ARGS);
+extern int i915_vblank_swap(DRM_IOCTL_ARGS);
 
 /* i915_mem.c */
 extern int i915_mem_alloc(DRM_IOCTL_ARGS);
@@ -257,6 +270,10 @@ extern int i915_wait_ring(drm_device_t * dev, int n, const char *caller);
 
 #define GFX_OP_DRAWRECT_INFO_I965 ((0x7900<<16)|0x2)
 
+#define XY_SRC_COPY_BLT_CMD             ((2<<29)|(0x53<<22)|6)
+#define XY_SRC_COPY_BLT_WRITE_ALPHA     (1<<21)
+#define XY_SRC_COPY_BLT_WRITE_RGB       (1<<20)
+
 #define MI_BATCH_BUFFER         ((0x30<<23)|1)
 #define MI_BATCH_BUFFER_START   (0x31<<23)
 #define MI_BATCH_BUFFER_END     (0xA<<23)
diff --git a/drivers/char/drm/i915_irq.c b/drivers/char/drm/i915_irq.c
index 33d40187696a..a93f1f37ec6a 100644
--- a/drivers/char/drm/i915_irq.c
+++ b/drivers/char/drm/i915_irq.c
@@ -37,6 +37,99 @@
 
 #define MAX_NOPID ((u32)~0)
 
+/**
+ * Emit blits for scheduled buffer swaps.
+ *
+ * This function will be called with the HW lock held.
+ */
+static void i915_vblank_tasklet(drm_device_t *dev)
+{
+        drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
+        unsigned int irqflags;
+        struct list_head *list, *tmp;
+
+        DRM_DEBUG("\n");
+
+        spin_lock_irqsave(&dev_priv->swaps_lock, irqflags);
+
+        list_for_each_safe(list, tmp, &dev_priv->vbl_swaps.head) {
+                drm_i915_vbl_swap_t *vbl_swap =
+                        list_entry(list, drm_i915_vbl_swap_t, head);
+                atomic_t *counter = vbl_swap->pipe ? &dev->vbl_received2 :
+                        &dev->vbl_received;
+
+                if ((atomic_read(counter) - vbl_swap->sequence) <= (1<<23)) {
+                        drm_drawable_info_t *drw;
+
+                        spin_unlock(&dev_priv->swaps_lock);
+
+                        spin_lock(&dev->drw_lock);
+
+                        drw = drm_get_drawable_info(dev, vbl_swap->drw_id);
+                                
+                        if (drw) {
+                                int i, num_rects = drw->num_rects;
+                                drm_clip_rect_t *rect = drw->rects;
+                                drm_i915_sarea_t *sarea_priv =
+                                    dev_priv->sarea_priv;
+                                u32 cpp = dev_priv->cpp;
+                                u32 cmd = (cpp == 4) ? (XY_SRC_COPY_BLT_CMD |
+                                                        XY_SRC_COPY_BLT_WRITE_ALPHA |
+                                                        XY_SRC_COPY_BLT_WRITE_RGB)
+                                                     : XY_SRC_COPY_BLT_CMD;
+                                u32 pitchropcpp = (sarea_priv->pitch * cpp) |
+                                                  (0xcc << 16) | (cpp << 23) |
+                                                  (1 << 24);
+                                RING_LOCALS;
+
+                                i915_kernel_lost_context(dev);
+
+                                BEGIN_LP_RING(6);
+
+                                OUT_RING(GFX_OP_DRAWRECT_INFO);
+                                OUT_RING(0);
+                                OUT_RING(0);
+                                OUT_RING(sarea_priv->width |
+                                         sarea_priv->height << 16);
+                                OUT_RING(sarea_priv->width |
+                                         sarea_priv->height << 16);
+                                OUT_RING(0);
+
+                                ADVANCE_LP_RING();
+
+                                sarea_priv->ctxOwner = DRM_KERNEL_CONTEXT;
+
+                                for (i = 0; i < num_rects; i++, rect++) {
+                                        BEGIN_LP_RING(8);
+
+                                        OUT_RING(cmd);
+                                        OUT_RING(pitchropcpp);
+                                        OUT_RING((rect->y1 << 16) | rect->x1);
+                                        OUT_RING((rect->y2 << 16) | rect->x2);
+                                        OUT_RING(sarea_priv->front_offset);
+                                        OUT_RING((rect->y1 << 16) | rect->x1);
+                                        OUT_RING(pitchropcpp & 0xffff);
+                                        OUT_RING(sarea_priv->back_offset);
+
+                                        ADVANCE_LP_RING();
+                                }
+                        }
+
+                        spin_unlock(&dev->drw_lock);
+
+                        spin_lock(&dev_priv->swaps_lock);
+
+                        list_del(list);
+
+                        drm_free(vbl_swap, sizeof(*vbl_swap), DRM_MEM_DRIVER);
+
+                        dev_priv->swaps_pending--;
+                }
+        }
+
+        spin_unlock_irqrestore(&dev_priv->swaps_lock, irqflags);
+}
+
 irqreturn_t i915_driver_irq_handler(DRM_IRQ_ARGS)
 {
         drm_device_t *dev = (drm_device_t *) arg;
@@ -72,6 +165,8 @@ irqreturn_t i915_driver_irq_handler(DRM_IRQ_ARGS)
 
                 DRM_WAKEUP(&dev->vbl_queue);
                 drm_vbl_send_signals(dev);
+
+                drm_locked_tasklet(dev, i915_vblank_tasklet);
         }
 
         return IRQ_HANDLED;
@@ -271,6 +366,90 @@ int i915_vblank_pipe_get(DRM_IOCTL_ARGS)
         return 0;
 }
 
+/**
+ * Schedule buffer swap at given vertical blank.
+ */
+int i915_vblank_swap(DRM_IOCTL_ARGS)
+{
+        DRM_DEVICE;
+        drm_i915_private_t *dev_priv = dev->dev_private;
+        drm_i915_vblank_swap_t swap;
+        drm_i915_vbl_swap_t *vbl_swap;
+        unsigned int irqflags;
+        struct list_head *list;
+
+        if (!dev_priv) {
+                DRM_ERROR("%s called with no initialization\n", __func__);
+                return DRM_ERR(EINVAL);
+        }
+
+        if (dev_priv->sarea_priv->rotation) {
+                DRM_DEBUG("Rotation not supported\n");
+                return DRM_ERR(EINVAL);
+        }
+
+        if (dev_priv->swaps_pending >= 100) {
+                DRM_DEBUG("Too many swaps queued\n");
+                return DRM_ERR(EBUSY);
+        }
+
+        DRM_COPY_FROM_USER_IOCTL(swap, (drm_i915_vblank_swap_t __user *) data,
+                                 sizeof(swap));
+
+        if (swap.pipe > 1 || !(dev_priv->vblank_pipe & (1 << swap.pipe))) {
+                DRM_ERROR("Invalid pipe %d\n", swap.pipe);
+                return DRM_ERR(EINVAL);
+        }
+
+        spin_lock_irqsave(&dev->drw_lock, irqflags);
+
+        if (!drm_get_drawable_info(dev, swap.drawable)) {
+                spin_unlock_irqrestore(&dev->drw_lock, irqflags);
+                DRM_ERROR("Invalid drawable ID %d\n", swap.drawable);
+                return DRM_ERR(EINVAL);
+        }
+
+        spin_unlock_irqrestore(&dev->drw_lock, irqflags);
+
+        spin_lock_irqsave(&dev_priv->swaps_lock, irqflags);
+
+        list_for_each(list, &dev_priv->vbl_swaps.head) {
+                vbl_swap = list_entry(list, drm_i915_vbl_swap_t, head);
+
+                if (vbl_swap->drw_id == swap.drawable &&
+                    vbl_swap->pipe == swap.pipe &&
+                    vbl_swap->sequence == swap.sequence) {
+                        spin_unlock_irqrestore(&dev_priv->swaps_lock, irqflags);
+                        DRM_DEBUG("Already scheduled\n");
+                        return 0;
+                }
+        }
+
+        spin_unlock_irqrestore(&dev_priv->swaps_lock, irqflags);
+
+        vbl_swap = drm_calloc(1, sizeof(vbl_swap), DRM_MEM_DRIVER);
+
+        if (!vbl_swap) {
+                DRM_ERROR("Failed to allocate memory to queue swap\n");
+                return DRM_ERR(ENOMEM);
+        }
+
+        DRM_DEBUG("\n");
+
+        vbl_swap->drw_id = swap.drawable;
+        vbl_swap->pipe = swap.pipe;
+        vbl_swap->sequence = swap.sequence;
+
+        spin_lock_irqsave(&dev_priv->swaps_lock, irqflags);
+
+        list_add_tail((struct list_head *)vbl_swap, &dev_priv->vbl_swaps.head);
+        dev_priv->swaps_pending++;
+
+        spin_unlock_irqrestore(&dev_priv->swaps_lock, irqflags);
+
+        return 0;
+}
+
 /* drm_dma.h hooks
 */
 void i915_driver_irq_preinstall(drm_device_t * dev)
@@ -286,6 +465,10 @@ void i915_driver_irq_postinstall(drm_device_t * dev)
 {
         drm_i915_private_t *dev_priv = (drm_i915_private_t *) dev->dev_private;
 
+        dev_priv->swaps_lock = SPIN_LOCK_UNLOCKED;
+        INIT_LIST_HEAD(&dev_priv->vbl_swaps.head);
+        dev_priv->swaps_pending = 0;
+
         i915_enable_interrupt(dev);
         DRM_INIT_WAITQUEUE(&dev_priv->irq_queue);
 }