drm/vmwgfx: Relax irq locking somewhat
Relax locking with the goal of reducing the number of locking cycles and
time spent with irqs disabled.
Signed-off-by: Thomas Hellstrom <thellstrom@vmware.com>
Reviewed-by: Sinclair Yeh <syeh@vmware.com>
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
index d1c34ab..a09cf85 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.c
@@ -643,7 +643,7 @@
init_waitqueue_head(&dev_priv->fence_queue);
init_waitqueue_head(&dev_priv->fifo_queue);
dev_priv->fence_queue_waiters = 0;
- atomic_set(&dev_priv->fifo_queue_waiters, 0);
+ dev_priv->fifo_queue_waiters = 0;
dev_priv->used_memory_size = 0;
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
index 198c8b1..a8ae9df 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_drv.h
@@ -440,13 +440,12 @@
spinlock_t waiter_lock;
int fence_queue_waiters; /* Protected by waiter_lock */
int goal_queue_waiters; /* Protected by waiter_lock */
- int cmdbuf_waiters; /* Protected by irq_lock */
- int error_waiters; /* Protected by irq_lock */
- atomic_t fifo_queue_waiters;
+ int cmdbuf_waiters; /* Protected by waiter_lock */
+ int error_waiters; /* Protected by waiter_lock */
+ int fifo_queue_waiters; /* Protected by waiter_lock */
uint32_t last_read_seqno;
- spinlock_t irq_lock;
struct vmw_fence_manager *fman;
- uint32_t irq_mask;
+ uint32_t irq_mask; /* Updates protected by waiter_lock */
/*
* Device state
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_fifo.c b/drivers/gpu/drm/vmwgfx/vmwgfx_fifo.c
index 0cbaf88..a8baf5f 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_fifo.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_fifo.c
@@ -252,7 +252,6 @@
unsigned long timeout)
{
long ret = 1L;
- unsigned long irq_flags;
if (likely(!vmw_fifo_is_full(dev_priv, bytes)))
return 0;
@@ -262,16 +261,8 @@
return vmw_fifo_wait_noirq(dev_priv, bytes,
interruptible, timeout);
- spin_lock(&dev_priv->waiter_lock);
- if (atomic_add_return(1, &dev_priv->fifo_queue_waiters) > 0) {
- spin_lock_irqsave(&dev_priv->irq_lock, irq_flags);
- outl(SVGA_IRQFLAG_FIFO_PROGRESS,
- dev_priv->io_start + VMWGFX_IRQSTATUS_PORT);
- dev_priv->irq_mask |= SVGA_IRQFLAG_FIFO_PROGRESS;
- vmw_write(dev_priv, SVGA_REG_IRQMASK, dev_priv->irq_mask);
- spin_unlock_irqrestore(&dev_priv->irq_lock, irq_flags);
- }
- spin_unlock(&dev_priv->waiter_lock);
+ vmw_generic_waiter_add(dev_priv, SVGA_IRQFLAG_FIFO_PROGRESS,
+ &dev_priv->fifo_queue_waiters);
if (interruptible)
ret = wait_event_interruptible_timeout
@@ -287,14 +278,8 @@
else if (likely(ret > 0))
ret = 0;
- spin_lock(&dev_priv->waiter_lock);
- if (atomic_dec_and_test(&dev_priv->fifo_queue_waiters)) {
- spin_lock_irqsave(&dev_priv->irq_lock, irq_flags);
- dev_priv->irq_mask &= ~SVGA_IRQFLAG_FIFO_PROGRESS;
- vmw_write(dev_priv, SVGA_REG_IRQMASK, dev_priv->irq_mask);
- spin_unlock_irqrestore(&dev_priv->irq_lock, irq_flags);
- }
- spin_unlock(&dev_priv->waiter_lock);
+ vmw_generic_waiter_remove(dev_priv, SVGA_IRQFLAG_FIFO_PROGRESS,
+ &dev_priv->fifo_queue_waiters);
return ret;
}
diff --git a/drivers/gpu/drm/vmwgfx/vmwgfx_irq.c b/drivers/gpu/drm/vmwgfx/vmwgfx_irq.c
index ac3eccd..0c7e172 100644
--- a/drivers/gpu/drm/vmwgfx/vmwgfx_irq.c
+++ b/drivers/gpu/drm/vmwgfx/vmwgfx_irq.c
@@ -36,15 +36,13 @@
struct vmw_private *dev_priv = vmw_priv(dev);
uint32_t status, masked_status;
- spin_lock(&dev_priv->irq_lock);
status = inl(dev_priv->io_start + VMWGFX_IRQSTATUS_PORT);
- masked_status = status & dev_priv->irq_mask;
- spin_unlock(&dev_priv->irq_lock);
+ masked_status = status & READ_ONCE(dev_priv->irq_mask);
if (likely(status))
outl(status, dev_priv->io_start + VMWGFX_IRQSTATUS_PORT);
- if (!masked_status)
+ if (!status)
return IRQ_NONE;
if (masked_status & (SVGA_IRQFLAG_ANY_FENCE |
@@ -190,65 +188,51 @@
return ret;
}
+void vmw_generic_waiter_add(struct vmw_private *dev_priv,
+ u32 flag, int *waiter_count)
+{
+ spin_lock_bh(&dev_priv->waiter_lock);
+ if ((*waiter_count)++ == 0) {
+ outl(flag, dev_priv->io_start + VMWGFX_IRQSTATUS_PORT);
+ dev_priv->irq_mask |= flag;
+ vmw_write(dev_priv, SVGA_REG_IRQMASK, dev_priv->irq_mask);
+ }
+ spin_unlock_bh(&dev_priv->waiter_lock);
+}
+
+void vmw_generic_waiter_remove(struct vmw_private *dev_priv,
+ u32 flag, int *waiter_count)
+{
+ spin_lock_bh(&dev_priv->waiter_lock);
+ if (--(*waiter_count) == 0) {
+ dev_priv->irq_mask &= ~flag;
+ vmw_write(dev_priv, SVGA_REG_IRQMASK, dev_priv->irq_mask);
+ }
+ spin_unlock_bh(&dev_priv->waiter_lock);
+}
+
void vmw_seqno_waiter_add(struct vmw_private *dev_priv)
{
- spin_lock(&dev_priv->waiter_lock);
- 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);
- dev_priv->irq_mask |= SVGA_IRQFLAG_ANY_FENCE;
- vmw_write(dev_priv, SVGA_REG_IRQMASK, dev_priv->irq_mask);
- spin_unlock_irqrestore(&dev_priv->irq_lock, irq_flags);
- }
- spin_unlock(&dev_priv->waiter_lock);
+ vmw_generic_waiter_add(dev_priv, SVGA_IRQFLAG_ANY_FENCE,
+ &dev_priv->fence_queue_waiters);
}
void vmw_seqno_waiter_remove(struct vmw_private *dev_priv)
{
- spin_lock(&dev_priv->waiter_lock);
- if (--dev_priv->fence_queue_waiters == 0) {
- unsigned long irq_flags;
-
- spin_lock_irqsave(&dev_priv->irq_lock, irq_flags);
- dev_priv->irq_mask &= ~SVGA_IRQFLAG_ANY_FENCE;
- vmw_write(dev_priv, SVGA_REG_IRQMASK, dev_priv->irq_mask);
- spin_unlock_irqrestore(&dev_priv->irq_lock, irq_flags);
- }
- spin_unlock(&dev_priv->waiter_lock);
+ vmw_generic_waiter_remove(dev_priv, SVGA_IRQFLAG_ANY_FENCE,
+ &dev_priv->fence_queue_waiters);
}
-
void vmw_goal_waiter_add(struct vmw_private *dev_priv)
{
- spin_lock(&dev_priv->waiter_lock);
- if (dev_priv->goal_queue_waiters++ == 0) {
- unsigned long irq_flags;
-
- spin_lock_irqsave(&dev_priv->irq_lock, irq_flags);
- outl(SVGA_IRQFLAG_FENCE_GOAL,
- dev_priv->io_start + VMWGFX_IRQSTATUS_PORT);
- dev_priv->irq_mask |= SVGA_IRQFLAG_FENCE_GOAL;
- vmw_write(dev_priv, SVGA_REG_IRQMASK, dev_priv->irq_mask);
- spin_unlock_irqrestore(&dev_priv->irq_lock, irq_flags);
- }
- spin_unlock(&dev_priv->waiter_lock);
+ vmw_generic_waiter_add(dev_priv, SVGA_IRQFLAG_FENCE_GOAL,
+ &dev_priv->goal_queue_waiters);
}
void vmw_goal_waiter_remove(struct vmw_private *dev_priv)
{
- spin_lock(&dev_priv->waiter_lock);
- if (--dev_priv->goal_queue_waiters == 0) {
- unsigned long irq_flags;
-
- spin_lock_irqsave(&dev_priv->irq_lock, irq_flags);
- dev_priv->irq_mask &= ~SVGA_IRQFLAG_FENCE_GOAL;
- vmw_write(dev_priv, SVGA_REG_IRQMASK, dev_priv->irq_mask);
- spin_unlock_irqrestore(&dev_priv->irq_lock, irq_flags);
- }
- spin_unlock(&dev_priv->waiter_lock);
+ vmw_generic_waiter_remove(dev_priv, SVGA_IRQFLAG_FENCE_GOAL,
+ &dev_priv->goal_queue_waiters);
}
int vmw_wait_seqno(struct vmw_private *dev_priv,
@@ -305,7 +289,6 @@
if (!(dev_priv->capabilities & SVGA_CAP_IRQMASK))
return;
- spin_lock_init(&dev_priv->irq_lock);
status = inl(dev_priv->io_start + VMWGFX_IRQSTATUS_PORT);
outl(status, dev_priv->io_start + VMWGFX_IRQSTATUS_PORT);
}
@@ -328,30 +311,3 @@
status = inl(dev_priv->io_start + VMWGFX_IRQSTATUS_PORT);
outl(status, dev_priv->io_start + VMWGFX_IRQSTATUS_PORT);
}
-
-void vmw_generic_waiter_add(struct vmw_private *dev_priv,
- u32 flag, int *waiter_count)
-{
- unsigned long irq_flags;
-
- spin_lock_irqsave(&dev_priv->irq_lock, irq_flags);
- if ((*waiter_count)++ == 0) {
- outl(flag, dev_priv->io_start + VMWGFX_IRQSTATUS_PORT);
- dev_priv->irq_mask |= flag;
- vmw_write(dev_priv, SVGA_REG_IRQMASK, dev_priv->irq_mask);
- }
- spin_unlock_irqrestore(&dev_priv->irq_lock, irq_flags);
-}
-
-void vmw_generic_waiter_remove(struct vmw_private *dev_priv,
- u32 flag, int *waiter_count)
-{
- unsigned long irq_flags;
-
- spin_lock_irqsave(&dev_priv->irq_lock, irq_flags);
- if (--(*waiter_count) == 0) {
- dev_priv->irq_mask &= ~flag;
- vmw_write(dev_priv, SVGA_REG_IRQMASK, dev_priv->irq_mask);
- }
- spin_unlock_irqrestore(&dev_priv->irq_lock, irq_flags);
-}