[PATCH 03/15] platform: goldfish: pipe: Remove the goldfish_pipe_dev global variable

From: rkir
Date: Tue Oct 02 2018 - 18:20:17 EST


From: Roman Kiryanov <rkir@xxxxxxxxxx>

This is the last patch in the series of patches to remove mutable
global variables to introduce another version of the pipe driver
for the older host interface. I don't want to have two driver
states where only one is used.

Signed-off-by: Roman Kiryanov <rkir@xxxxxxxxxx>
---
drivers/platform/goldfish/goldfish_pipe.c | 66 +++++++++++++----------
1 file changed, 37 insertions(+), 29 deletions(-)

diff --git a/drivers/platform/goldfish/goldfish_pipe.c b/drivers/platform/goldfish/goldfish_pipe.c
index 8ca709b45e1f..4013832f38fb 100644
--- a/drivers/platform/goldfish/goldfish_pipe.c
+++ b/drivers/platform/goldfish/goldfish_pipe.c
@@ -169,6 +169,9 @@ struct goldfish_pipe {
* waiting to be awoken.
*/
struct goldfish_pipe_dev {
+ /* A magic number to check if this is an instance of this struct */
+ void *magic;
+
/*
* Global device spinlock. Protects the following members:
* - pipes, pipes_capacity
@@ -215,8 +218,6 @@ struct goldfish_pipe_dev {
struct miscdevice miscdev;
};

-static struct goldfish_pipe_dev goldfish_pipe_dev;
-
static int goldfish_pipe_cmd_locked(struct goldfish_pipe *pipe,
enum PipeCmdCode cmd)
{
@@ -611,6 +612,9 @@ static void goldfish_interrupt_task(unsigned long dev_addr)
}
}

+static void goldfish_pipe_device_deinit(struct platform_device *pdev,
+ struct goldfish_pipe_dev *dev);
+
/*
* The general idea of the interrupt handling:
*
@@ -631,7 +635,7 @@ static irqreturn_t goldfish_pipe_interrupt(int irq, void *dev_id)
unsigned long flags;
struct goldfish_pipe_dev *dev = dev_id;

- if (dev != &goldfish_pipe_dev)
+ if (dev->magic != &goldfish_pipe_device_deinit)
return IRQ_NONE;

/* Request the signalled pipes from the device */
@@ -683,6 +687,14 @@ static int get_free_pipe_id_locked(struct goldfish_pipe_dev *dev)
return id;
}

+/* A helper function to get the instance of goldfish_pipe_dev from file */
+static struct goldfish_pipe_dev *to_goldfish_pipe_dev(struct file *file)
+{
+ struct miscdevice *miscdev = file->private_data;
+
+ return container_of(miscdev, struct goldfish_pipe_dev, miscdev);
+}
+
/**
* goldfish_pipe_open - open a channel to the AVD
* @inode: inode of device
@@ -696,7 +708,7 @@ static int get_free_pipe_id_locked(struct goldfish_pipe_dev *dev)
*/
static int goldfish_pipe_open(struct inode *inode, struct file *file)
{
- struct goldfish_pipe_dev *dev = &goldfish_pipe_dev;
+ struct goldfish_pipe_dev *dev = to_goldfish_pipe_dev(file);
unsigned long flags;
int id;
int status;
@@ -804,9 +816,9 @@ static void write_pa_addr(void *addr, void __iomem *portl, void __iomem *porth)
writel(lower_32_bits(paddr), portl);
}

-static int goldfish_pipe_device_init(struct platform_device *pdev)
+static int goldfish_pipe_device_init(struct platform_device *pdev,
+ struct goldfish_pipe_dev *dev)
{
- struct goldfish_pipe_dev *dev = &goldfish_pipe_dev;
int err;

tasklet_init(&dev->irq_tasklet, &goldfish_interrupt_task,
@@ -861,26 +873,29 @@ static int goldfish_pipe_device_init(struct platform_device *pdev)
dev->base + PIPE_REG_OPEN_BUFFER,
dev->base + PIPE_REG_OPEN_BUFFER_HIGH);

+ platform_set_drvdata(pdev, dev);
return 0;
}

-static void goldfish_pipe_device_deinit(struct platform_device *pdev)
+static void goldfish_pipe_device_deinit(struct platform_device *pdev,
+ struct goldfish_pipe_dev *dev)
{
- misc_deregister(&goldfish_pipe_dev.miscdev);
- tasklet_kill(&goldfish_pipe_dev.irq_tasklet);
- kfree(goldfish_pipe_dev.pipes);
- free_page((unsigned long)goldfish_pipe_dev.buffers);
+ misc_deregister(&dev->miscdev);
+ tasklet_kill(&dev->irq_tasklet);
+ kfree(dev->pipes);
+ free_page((unsigned long)dev->buffers);
}

static int goldfish_pipe_probe(struct platform_device *pdev)
{
- int err;
struct resource *r;
- struct goldfish_pipe_dev *dev = &goldfish_pipe_dev;
+ struct goldfish_pipe_dev *dev;

- /* not thread safe, but this should not happen */
- WARN_ON(dev->base);
+ dev = devm_kzalloc(&pdev->dev, sizeof(*dev), GFP_KERNEL);
+ if (!dev)
+ return -ENOMEM;

+ dev->magic = &goldfish_pipe_device_deinit;
spin_lock_init(&dev->lock);

r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -895,10 +910,9 @@ static int goldfish_pipe_probe(struct platform_device *pdev)
}

r = platform_get_resource(pdev, IORESOURCE_IRQ, 0);
- if (!r) {
- err = -EINVAL;
- goto error;
- }
+ if (!r)
+ return -EINVAL;
+
dev->irq = r->start;

/*
@@ -913,20 +927,14 @@ static int goldfish_pipe_probe(struct platform_device *pdev)
if (WARN_ON(dev->version < PIPE_CURRENT_DEVICE_VERSION))
return -EINVAL;

- err = goldfish_pipe_device_init(pdev);
- if (!err)
- return 0;
-
-error:
- dev->base = NULL;
- return err;
+ return goldfish_pipe_device_init(pdev, dev);
}

static int goldfish_pipe_remove(struct platform_device *pdev)
{
- struct goldfish_pipe_dev *dev = &goldfish_pipe_dev;
- goldfish_pipe_device_deinit(pdev);
- dev->base = NULL;
+ struct goldfish_pipe_dev *dev = platform_get_drvdata(pdev);
+
+ goldfish_pipe_device_deinit(pdev, dev);
return 0;
}

--
2.19.0.605.g01d371f741-goog