Re: [PATCH v6 2/2] staging: ion: create one device entry per heap

On 10/23/2017 08:55 AM, Benjamin Gaignard wrote:

Instead a getting only one common device "/dev/ion" for all the heaps this patch allow to create one device entry ("/dev/ionX") per heap. Getting an entry per heap could allow to set security rules per heap and global ones for all heaps.

Allocation requests will be only allowed if the mask_id match with device minor. Query request could be done on any of the devices.

I'm wondering if we should always keep /dev/ion for the query ioctl and just disallow allocation from /dev/ion. I guess running the query ioctl on /dev/ion0 always wouldn't be too bad? Anyone else have strong opinions?

Ion devices are parentless so it is need to add platform_bus as parent and platform_bus_type as bus to be put in /sys/device/paltform. Those two parameters need platform_device.h to be included but include files weren't in alphabetic order so I reorder them correctly.

I'm not a fan of the platform bus but I have mixed feelings about creating a dedicated bus type. I guess if we really need a bus type we can do it later?

Thanks, Laura

Signed-off-by: Benjamin Gaignard benjamin.gaignard@linaro.org

drivers/staging/android/TODO | 1 - drivers/staging/android/ion/Kconfig | 7 +++++ drivers/staging/android/ion/ion-ioctl.c | 18 +++++++++-- drivers/staging/android/ion/ion.c | 53 ++++++++++++++++++++++++++------- drivers/staging/android/ion/ion.h | 15 ++++++++-- 5 files changed, 79 insertions(+), 15 deletions(-)

diff --git a/drivers/staging/android/TODO b/drivers/staging/android/TODO index 5f14247..d770ffa 100644 --- a/drivers/staging/android/TODO +++ b/drivers/staging/android/TODO @@ -9,7 +9,6 @@ TODO: ion/

• Add dt-bindings for remaining heaps (chunk and carveout heaps). This would involve putting appropriate bindings in a memory node for Ion to find.
• • Split /dev/ion up into multiple nodes (e.g. /dev/ion/heap0)
  • Better test framework (integration with VGEM was suggested)

Please send patches to Greg Kroah-Hartman greg@kroah.com and Cc: diff --git a/drivers/staging/android/ion/Kconfig b/drivers/staging/android/ion/Kconfig index a517b2d..cb4666e 100644 --- a/drivers/staging/android/ion/Kconfig +++ b/drivers/staging/android/ion/Kconfig @@ -10,6 +10,13 @@ menuconfig ION If you're not using Android its probably safe to say N here.

+config ION_LEGACY_DEVICE_API

• bool "Keep using Ion legacy misc device API"
• depends on ION
• help

•  Choose this option to keep using Ion legacy misc device API
  

•  i.e. /dev/ion
  

config ION_SYSTEM_HEAP bool "Ion system heap" depends on ION diff --git a/drivers/staging/android/ion/ion-ioctl.c b/drivers/staging/android/ion/ion-ioctl.c index e26b786..bb5c77b 100644 --- a/drivers/staging/android/ion/ion-ioctl.c +++ b/drivers/staging/android/ion/ion-ioctl.c @@ -25,7 +25,8 @@ union ion_ioctl_arg { struct ion_heap_query query; };

-static int validate_ioctl_arg(unsigned int cmd, union ion_ioctl_arg *arg) +static int validate_ioctl_arg(struct file *filp,

• 	      unsigned int cmd, union ion_ioctl_arg *arg)
  

{ switch (cmd) { case ION_IOC_HEAP_QUERY: @@ -34,6 +35,19 @@ static int validate_ioctl_arg(unsigned int cmd, union ion_ioctl_arg *arg) arg->query.reserved2 ) return -EINVAL; break;

• case ION_IOC_ALLOC:
• {

• int mask = 1 << iminor(filp->f_inode);
  

+#ifdef CONFIG_ION_LEGACY_DEVICE_API

• if (imajor(filp->f_inode) == MISC_MAJOR)
  

• 	return 0;
  

+#endif

• if (!(arg->allocation.heap_id_mask & mask))
  

• 	return -EINVAL;
  

• break;
  

• } default: break; }

@@ -69,7 +83,7 @@ long ion_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) if (copy_from_user(&data, (void __user *)arg, _IOC_SIZE(cmd))) return -EFAULT;

• ret = validate_ioctl_arg(cmd, &data);

• ret = validate_ioctl_arg(filp, cmd, &data); if (WARN_ON_ONCE(ret)) return ret;

diff --git a/drivers/staging/android/ion/ion.c b/drivers/staging/android/ion/ion.c index 93e2c90..dd66f55 100644 --- a/drivers/staging/android/ion/ion.c +++ b/drivers/staging/android/ion/ion.c @@ -15,31 +15,35 @@

*/

+#include <linux/anon_inodes.h> +#include <linux/debugfs.h> #include <linux/device.h> +#include <linux/dma-buf.h> #include <linux/err.h> +#include <linux/export.h> #include <linux/file.h> #include <linux/freezer.h> #include <linux/fs.h> -#include <linux/anon_inodes.h> +#include <linux/idr.h> #include <linux/kthread.h> #include <linux/list.h> #include <linux/memblock.h> #include <linux/miscdevice.h> -#include <linux/export.h> #include <linux/mm.h> #include <linux/mm_types.h> +#include <linux/platform_device.h> #include <linux/rbtree.h> -#include <linux/slab.h> +#include <linux/sched/task.h> #include <linux/seq_file.h> +#include <linux/slab.h> #include <linux/uaccess.h> #include <linux/vmalloc.h> -#include <linux/debugfs.h> -#include <linux/dma-buf.h> -#include <linux/idr.h> -#include <linux/sched/task.h>

#include "ion.h"

+#define ION_DEV_MAX 32 +#define ION_NAME "ion"

static struct ion_device *internal_dev; static int heap_id;

@@ -537,15 +541,30 @@ 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.parent = &platform_bus;

• heap->ddev.bus = &platform_bus_type;

• heap->ddev.devt = MKDEV(MAJOR(internal_dev->devt), heap_id);

• dev_set_name(&heap->ddev, ION_NAME"%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 +602,8 @@ void ion_device_add_heap(struct ion_heap *heap)

dev->heap_cnt++; up_write(&dev->lock);

• return ret;

} EXPORT_SYMBOL(ion_device_add_heap);

@@ -595,8 +616,9 @@ 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.name = ION_NAME; idev->dev.fops = &ion_fops; idev->dev.parent = NULL; ret = misc_register(&idev->dev);

@@ -605,8 +627,19 @@ static int ion_device_create(void) kfree(idev); return ret; } +#endif

• ret = alloc_chrdev_region(&idev->devt, 0, ION_DEV_MAX, ION_NAME);
• 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);

• idev->debug_root = debugfs_create_dir(ION_NAME, NULL); if (!idev->debug_root) { pr_err("ion: failed to create debugfs root directory.\n"); goto debugfs_done;

diff --git a/drivers/staging/android/ion/ion.h b/drivers/staging/android/ion/ion.h index 621e5f7..2b00ccb 100644 --- a/drivers/staging/android/ion/ion.h +++ b/drivers/staging/android/ion/ion.h @@ -17,16 +17,19 @@ #ifndef _ION_H #define _ION_H

+#include <linux/cdev.h> #include <linux/device.h> #include <linux/dma-direction.h> #include <linux/kref.h> +#ifdef CONFIG_ION_LEGACY_DEVICE_API +#include <linux/miscdevice.h> +#endif #include <linux/mm_types.h> #include <linux/mutex.h> #include <linux/rbtree.h> #include <linux/sched.h> #include <linux/shrinker.h> #include <linux/types.h> -#include <linux/miscdevice.h>

#include "../uapi/ion.h"

@@ -91,12 +94,16 @@ void ion_buffer_destroy(struct ion_buffer *buffer); /**

• struct ion_device - the metadata of the ion device node
• @dev: the actual misc device

• • @devt: Ion device
  • @buffers: an rb tree of all the existing buffers
  • @buffer_lock: lock protecting the tree of buffers
  • @lock: rwsem protecting the tree of heaps and clients
  */

struct ion_device { +#ifdef CONFIG_ION_LEGACY_DEVICE_API struct miscdevice dev; +#endif

• dev_t devt; struct rb_root buffers; struct mutex buffer_lock; struct rw_semaphore lock;

@@ -152,6 +159,8 @@ struct ion_heap_ops {

• struct ion_heap - represents a heap in the system
• @node: rb node to put the heap on the device's tree of heaps
• @dev: back pointer to the ion_device

• • @ddev: device structure
• • @chrdev: associated character device
  • @type: type of heap
  • @ops: ops struct as above
  • @flags: flags

@@ -176,6 +185,8 @@ struct ion_heap_ops { struct ion_heap { struct plist_node node; struct ion_device *dev;

• struct device ddev;
• struct cdev chrdev; enum ion_heap_type type; struct ion_heap_ops *ops; unsigned long flags;

@@ -212,7 +223,7 @@ bool ion_buffer_fault_user_mappings(struct ion_buffer *buffer);

• ion_device_add_heap - adds a heap to the ion device
• @heap: the heap to add

*/ -void ion_device_add_heap(struct ion_heap *heap); +int ion_device_add_heap(struct ion_heap *heap);

/**

• some helpers for common operations on buffers using the sg_table