[PATCH v2 01/15] platform: goldfish: pipe: Move the file-scope goldfish_interrupt_tasklet variable into the driver state

[rkir@google.com]

From: Roman Kiryanov <rkir@google.com>

This is a series of patches to move mutable file-scope variables
into the driver state. This change will help to introduce another
version of the pipe driver (with different state) for the older
host interface or having several instances of this device.

Signed-off-by: Roman Kiryanov <rkir@google.com>
---
Changes in v2:
 - Updated the commit message.

 drivers/platform/goldfish/goldfish_pipe.c | 24 +++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/drivers/platform/goldfish/goldfish_pipe.c b/drivers/platform/goldfish/goldfish_pipe.c
index 56665e879e5a..ba9aede17d57 100644
--- a/drivers/platform/goldfish/goldfish_pipe.c
+++ b/drivers/platform/goldfish/goldfish_pipe.c
@@ -208,6 +208,9 @@ struct goldfish_pipe_dev {
 	int irq;
 	int version;
 	unsigned char __iomem *base;
+
+	/* an irq tasklet to run goldfish_interrupt_task */
+	struct tasklet_struct irq_tasklet;
 };
 
 static struct goldfish_pipe_dev goldfish_pipe_dev;
@@ -582,14 +585,14 @@ static struct goldfish_pipe *signalled_pipes_pop_front(
 	return pipe;
 }
 
-static void goldfish_interrupt_task(unsigned long unused)
+static void goldfish_interrupt_task(unsigned long dev_addr)
 {
 	/* Iterate over the signalled pipes and wake them one by one */
+	struct goldfish_pipe_dev *dev = (struct goldfish_pipe_dev *)dev_addr;
 	struct goldfish_pipe *pipe;
 	int wakes;
 
-	while ((pipe = signalled_pipes_pop_front(&goldfish_pipe_dev, &wakes)) !=
-			NULL) {
+	while ((pipe = signalled_pipes_pop_front(dev, &wakes)) != NULL) {
 		if (wakes & PIPE_WAKE_CLOSED) {
 			pipe->flags = 1 << BIT_CLOSED_ON_HOST;
 		} else {
@@ -605,7 +608,6 @@ static void goldfish_interrupt_task(unsigned long unused)
 		wake_up_interruptible(&pipe->wake_queue);
 	}
 }
-static DECLARE_TASKLET(goldfish_interrupt_tasklet, goldfish_interrupt_task, 0);
 
 /*
  * The general idea of the interrupt handling:
@@ -648,7 +650,7 @@ static irqreturn_t goldfish_pipe_interrupt(int irq, void *dev_id)
 
 	spin_unlock_irqrestore(&dev->lock, flags);
 
-	tasklet_schedule(&goldfish_interrupt_tasklet);
+	tasklet_schedule(&dev->irq_tasklet);
 	return IRQ_HANDLED;
 }
 
@@ -800,9 +802,14 @@ static void write_pa_addr(void *addr, void __iomem *portl, void __iomem *porth)
 static int goldfish_pipe_device_init(struct platform_device *pdev)
 {
 	struct goldfish_pipe_dev *dev = &goldfish_pipe_dev;
-	int err = devm_request_irq(&pdev->dev, dev->irq,
-				goldfish_pipe_interrupt,
-				IRQF_SHARED, "goldfish_pipe", dev);
+	int err;
+
+	tasklet_init(&dev->irq_tasklet, &goldfish_interrupt_task,
+		     (unsigned long)dev);
+
+	err = devm_request_irq(&pdev->dev, dev->irq,
+			       goldfish_pipe_interrupt,
+			       IRQF_SHARED, "goldfish_pipe", dev);
 	if (err) {
 		dev_err(&pdev->dev, "unable to allocate IRQ for v2\n");
 		return err;
@@ -854,6 +861,7 @@ static int goldfish_pipe_device_init(struct platform_device *pdev)
 static void goldfish_pipe_device_deinit(struct platform_device *pdev)
 {
 	misc_deregister(&goldfish_pipe_miscdev);
+	tasklet_kill(&goldfish_pipe_dev.irq_tasklet);
 	kfree(goldfish_pipe_dev.pipes);
 	free_page((unsigned long)goldfish_pipe_dev.buffers);
 }
-- 
2.19.0.605.g01d371f741-goog