Re: [PATCH v5 2/2] staging: ion: create one device entry per heap

2017-10-18 22:07 GMT+02:00 Laura Abbott [off-list ref]:

On 09/27/2017 06:20 AM, Benjamin Gaignard wrote:

quoted

diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c
index 93e2c90..092b24c 100644
--- a/drivers/staging/android/ion/ion.c
+++ b/drivers/staging/android/ion/ion.c

@@ -40,6 +40,8 @@

 #include "ion.h"

+#define ION_DEV_MAX 32
+
 static struct ion_device *internal_dev;
 static int heap_id;

@@ -537,15 +539,28 @@ static int debug_shrink_get(void *data, u64 *val)
 DEFINE_SIMPLE_ATTRIBUTE(debug_shrink_fops, debug_shrink_get,
                      debug_shrink_set, "%llu\n");

-void ion_device_add_heap(struct ion_heap *heap)
+int ion_device_add_heap(struct ion_heap *heap)
 {
      struct dentry *debug_file;
      struct ion_device *dev = internal_dev;
+     int ret = 0;

      if (!heap->ops->allocate || !heap->ops->free)
              pr_err("%s: can not add heap with invalid ops struct.\n",
                     __func__);

+     if (heap_id >= ION_DEV_MAX)
+             return -EBUSY;
+
+     heap->ddev.devt = MKDEV(MAJOR(dev->devt), heap_id);
+     dev_set_name(&heap->ddev, "ion%d", heap_id);
+     device_initialize(&heap->ddev);
+     cdev_init(&heap->chrdev, &ion_fops);
+     heap->chrdev.owner = THIS_MODULE;
+     ret = cdev_device_add(&heap->chrdev, &heap->ddev);
+     if (ret < 0)
+             return ret;
+
      spin_lock_init(&heap->free_lock);
      heap->free_list_size = 0;

@@ -583,6 +598,8 @@ void ion_device_add_heap(struct ion_heap *heap)

      dev->heap_cnt++;
      up_write(&dev->lock);
+
+     return ret;
 }
 EXPORT_SYMBOL(ion_device_add_heap);

@@ -595,6 +612,7 @@ static int ion_device_create(void)
      if (!idev)
              return -ENOMEM;

+#ifdef CONFIG_ION_LEGACY_DEVICE_API
      idev->dev.minor = MISC_DYNAMIC_MINOR;
      idev->dev.name = "ion";
      idev->dev.fops = &ion_fops;

@@ -605,6 +623,17 @@ static int ion_device_create(void)
              kfree(idev);
              return ret;
      }
+#endif
+
+     ret = alloc_chrdev_region(&idev->devt, 0, ION_DEV_MAX, "ion");
+     if (ret) {
+             pr_err("ion: unable to allocate device\n");
+#ifdef CONFIG_ION_LEGACY_DEVICE_API
+             misc_deregister(&idev->dev);
+#endif
+             kfree(idev);
+             return ret;
+     }

      idev->debug_root = debugfs_create_dir("ion", NULL);
      if (!idev->debug_root) {

I'm not 100% sure about the device hierarchy here. We're
ending up with devices at the root of /sys/devices

/sys/devices # ls
breakpoint ion0 ion1 ion2 platform software system virtual

and the Android init system doesn't pick this up. I'll
admit to being out of my area here but I don't think
this looks quite right.

You are right it is because ion devices are parentless so they
directly put under /sys/devices directory. I will give them platform_bus
as parent to solve that problem.

Benjamin

Thanks,
Laura