vmwgfx: Make vmw_wait_seqno a bit more readable

Break out on-demand enabling and disabling of fence irqs to make
the function more readable. Also make dev_priv->fence_queue_waiters an int
instead of an atomic_t since we only manipulate it with dev_priv->hw_mutex
held.

Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Jakob Bornecrantz <jakob@vmware.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
index c8b5a53f140b997ff4f565f065a2ba6e5e76b7b5..4f65f1e34b8fc76ea3c97d23f9ffca3a8cdcc155 100644 (file)
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
@@ -291,7 +291,7 @@ static int vmw_driver_load(struct drm_device *dev, unsigned long chipset)
        mutex_init(&dev_priv->init_mutex);
        init_waitqueue_head(&dev_priv->fence_queue);
        init_waitqueue_head(&dev_priv->fifo_queue);
-       atomic_set(&dev_priv->fence_queue_waiters, 0);
+       dev_priv->fence_queue_waiters = 0;
        atomic_set(&dev_priv->fifo_queue_waiters, 0);
 
        dev_priv->io_start = pci_resource_start(dev->pdev, 0);

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
index 9c3016b53eacaa1d358ccb55571e3c11abacb3ea..3018871aaaffca16f000d00d5893db3e5472fb68 100644 (file)
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
@@ -241,7 +241,7 @@ struct vmw_private {
        atomic_t marker_seq;
        wait_queue_head_t fence_queue;
        wait_queue_head_t fifo_queue;
-       atomic_t fence_queue_waiters;
+       int fence_queue_waiters; /* Protected by hw_mutex */
        atomic_t fifo_queue_waiters;
        uint32_t last_read_seqno;
        spinlock_t irq_lock;

diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_irq.c b/drivers/gpu/drm/vmwgfx/vmwgfx_irq.c
index 48701d2c8c0ff7ef5a0f59a867d8fc65b5e5cb5b..13dde06b60be1bae17c1928bb7abbce853b65ead 100644 (file)
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_irq.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_irq.c
@@ -175,12 +175,43 @@ int vmw_fallback_wait(struct vmw_private *dev_priv,
        return ret;
 }
 
+static void vmw_seqno_waiter_add(struct vmw_private *dev_priv)
+{
+       mutex_lock(&dev_priv->hw_mutex);
+       if (dev_priv->fence_queue_waiters++ == 0) {
+               unsigned long irq_flags;
+
+               spin_lock_irqsave(&dev_priv->irq_lock, irq_flags);
+               outl(SVGA_IRQFLAG_ANY_FENCE,
+                    dev_priv->io_start + VMWGFX_IRQSTATUS_PORT);
+               vmw_write(dev_priv, SVGA_REG_IRQMASK,
+                         vmw_read(dev_priv, SVGA_REG_IRQMASK) |
+                         SVGA_IRQFLAG_ANY_FENCE);
+               spin_unlock_irqrestore(&dev_priv->irq_lock, irq_flags);
+       }
+       mutex_unlock(&dev_priv->hw_mutex);
+}
+
+static void vmw_seqno_waiter_remove(struct vmw_private *dev_priv)
+{
+       mutex_lock(&dev_priv->hw_mutex);
+       if (--dev_priv->fence_queue_waiters == 0) {
+               unsigned long irq_flags;
+
+               spin_lock_irqsave(&dev_priv->irq_lock, irq_flags);
+               vmw_write(dev_priv, SVGA_REG_IRQMASK,
+                         vmw_read(dev_priv, SVGA_REG_IRQMASK) &
+                         ~SVGA_IRQFLAG_ANY_FENCE);
+               spin_unlock_irqrestore(&dev_priv->irq_lock, irq_flags);
+       }
+       mutex_unlock(&dev_priv->hw_mutex);
+}
+
 int vmw_wait_seqno(struct vmw_private *dev_priv,
                      bool lazy, uint32_t seqno,
                      bool interruptible, unsigned long timeout)
 {
        long ret;
-       unsigned long irq_flags;
        struct vmw_fifo_state *fifo = &dev_priv->fifo;
 
        if (likely(dev_priv->last_read_seqno - seqno < VMW_FENCE_WRAP))
@@ -199,17 +230,7 @@ int vmw_wait_seqno(struct vmw_private *dev_priv,
                return vmw_fallback_wait(dev_priv, lazy, false, seqno,
                                         interruptible, timeout);
 
-       mutex_lock(&dev_priv->hw_mutex);
-       if (atomic_add_return(1, &dev_priv->fence_queue_waiters) > 0) {
-               spin_lock_irqsave(&dev_priv->irq_lock, irq_flags);
-               outl(SVGA_IRQFLAG_ANY_FENCE,
-                    dev_priv->io_start + VMWGFX_IRQSTATUS_PORT);
-               vmw_write(dev_priv, SVGA_REG_IRQMASK,
-                         vmw_read(dev_priv, SVGA_REG_IRQMASK) |
-                         SVGA_IRQFLAG_ANY_FENCE);
-               spin_unlock_irqrestore(&dev_priv->irq_lock, irq_flags);
-       }
-       mutex_unlock(&dev_priv->hw_mutex);
+       vmw_seqno_waiter_add(dev_priv);
 
        if (interruptible)
                ret = wait_event_interruptible_timeout
@@ -222,21 +243,13 @@ int vmw_wait_seqno(struct vmw_private *dev_priv,
                     vmw_seqno_passed(dev_priv, seqno),
                     timeout);
 
+       vmw_seqno_waiter_remove(dev_priv);
+
        if (unlikely(ret == 0))
                ret = -EBUSY;
        else if (likely(ret > 0))
                ret = 0;
 
-       mutex_lock(&dev_priv->hw_mutex);
-       if (atomic_dec_and_test(&dev_priv->fence_queue_waiters)) {
-               spin_lock_irqsave(&dev_priv->irq_lock, irq_flags);
-               vmw_write(dev_priv, SVGA_REG_IRQMASK,
-                         vmw_read(dev_priv, SVGA_REG_IRQMASK) &
-                         ~SVGA_IRQFLAG_ANY_FENCE);
-               spin_unlock_irqrestore(&dev_priv->irq_lock, irq_flags);
-       }
-       mutex_unlock(&dev_priv->hw_mutex);
-
        return ret;
 }