Ion clients currently lack a good method to determine what
heaps are available and what ids they map to. This leads
to tight coupling between user and kernel space and headaches.
Add a query ioctl to let userspace know the availability of
heaps.

Signed-off-by: Laura Abbott <labb...@redhat.com>
---
 drivers/staging/android/ion/ion-ioctl.c | 11 +++++++++
 drivers/staging/android/ion/ion.c       | 44 +++++++++++++++++++++++++++++++++
 drivers/staging/android/ion/ion_priv.h  |  3 +++
 drivers/staging/android/uapi/ion.h      | 39 +++++++++++++++++++++++++++++
 4 files changed, 97 insertions(+)

diff --git a/drivers/staging/android/ion/ion-ioctl.c 
b/drivers/staging/android/ion/ion-ioctl.c
index 53b9520..e76d517 100644
--- a/drivers/staging/android/ion/ion-ioctl.c
+++ b/drivers/staging/android/ion/ion-ioctl.c
@@ -28,6 +28,7 @@ union ion_ioctl_arg {
        struct ion_handle_data handle;
        struct ion_custom_data custom;
        struct ion_abi_version abi_version;
+       struct ion_heap_query query;
 };
 
 static int validate_ioctl_arg(unsigned int cmd, union ion_ioctl_arg *arg)
@@ -38,6 +39,11 @@ static int validate_ioctl_arg(unsigned int cmd, union 
ion_ioctl_arg *arg)
        case ION_IOC_ABI_VERSION:
                ret = arg->abi_version.reserved != 0;
                break;
+       case ION_IOC_HEAP_QUERY:
+               ret = arg->query.reserved0 != 0;
+               ret |= arg->query.reserved1 != 0;
+               ret |= arg->query.reserved2 != 0;
+               break;
        default:
                break;
        }
@@ -162,6 +168,11 @@ long ion_ioctl(struct file *filp, unsigned int cmd, 
unsigned long arg)
                data.abi_version.abi_version = ION_ABI_VERSION;
                break;
        }
+       case ION_IOC_HEAP_QUERY:
+       {
+               ret = ion_query_heaps(client, &data.query);
+               break;
+       }
        default:
                return -ENOTTY;
        }
diff --git a/drivers/staging/android/ion/ion.c 
b/drivers/staging/android/ion/ion.c
index 975b48f..91b765c 100644
--- a/drivers/staging/android/ion/ion.c
+++ b/drivers/staging/android/ion/ion.c
@@ -1174,6 +1174,49 @@ int ion_sync_for_device(struct ion_client *client, int 
fd)
        return 0;
 }
 
+int ion_query_heaps(struct ion_client *client, struct ion_heap_query *query)
+{
+       struct ion_device *dev = client->dev;
+       struct ion_heap_data __user *buffer =
+               (struct ion_heap_data __user *)query->heaps;
+       int ret = -EINVAL, cnt = 0, max_cnt;
+       struct ion_heap *heap;
+       struct ion_heap_data hdata;
+
+       memset(&hdata, 0, sizeof(hdata));
+
+       down_read(&dev->lock);
+       if (!buffer) {
+               query->cnt = dev->heap_cnt;
+               ret = 0;
+               goto out;
+       }
+
+       if (query->cnt <= 0)
+               goto out;
+
+       max_cnt = query->cnt;
+
+       plist_for_each_entry(heap, &dev->heaps, node) {
+               strncpy(hdata.name, heap->name, MAX_HEAP_NAME);
+               hdata.name[sizeof(hdata.name) - 1] = '\0';
+               hdata.type = heap->type;
+               hdata.heap_id = heap->id;
+
+               ret = copy_to_user(&buffer[cnt],
+                                  &hdata, sizeof(hdata));
+
+               cnt++;
+               if (cnt >= max_cnt)
+                       break;
+       }
+
+       query->cnt = cnt;
+out:
+       up_read(&dev->lock);
+       return ret;
+}
+
 static int ion_release(struct inode *inode, struct file *file)
 {
        struct ion_client *client = file->private_data;
@@ -1391,6 +1434,7 @@ void ion_device_add_heap(struct ion_device *dev, struct 
ion_heap *heap)
                }
        }
 
+       dev->heap_cnt++;
        up_write(&dev->lock);
 }
 EXPORT_SYMBOL(ion_device_add_heap);
diff --git a/drivers/staging/android/ion/ion_priv.h 
b/drivers/staging/android/ion/ion_priv.h
index 95df6a9..0d0c0aa 100644
--- a/drivers/staging/android/ion/ion_priv.h
+++ b/drivers/staging/android/ion/ion_priv.h
@@ -104,6 +104,7 @@ struct ion_device {
        struct dentry *debug_root;
        struct dentry *heaps_debug_root;
        struct dentry *clients_debug_root;
+       int heap_cnt;
 };
 
 /**
@@ -469,4 +470,6 @@ struct ion_handle *ion_handle_get_by_id(struct ion_client 
*client,
 
 int ion_handle_put(struct ion_handle *handle);
 
+int ion_query_heaps(struct ion_client *client, struct ion_heap_query *query);
+
 #endif /* _ION_PRIV_H */
diff --git a/drivers/staging/android/uapi/ion.h 
b/drivers/staging/android/uapi/ion.h
index 7ca4e8b..112f257 100644
--- a/drivers/staging/android/uapi/ion.h
+++ b/drivers/staging/android/uapi/ion.h
@@ -137,11 +137,41 @@ struct ion_custom_data {
 
 #define ION_ABI_VERSION                KERNEL_VERSION(0, 1, 0)
 
+#define MAX_HEAP_NAME                  32
+
 struct ion_abi_version {
        __u32 abi_version;
        __u32 reserved;
 };
 
+/**
+ * struct ion_heap_data - data about a heap
+ * @name - first 32 characters of the heap name
+ * @type - heap type
+ * @heap_id - heap id for the heap
+ */
+struct ion_heap_data {
+       char name[MAX_HEAP_NAME];
+       __u32 type;
+       __u32 heap_id;
+       __u32 reserved0;
+       __u32 reserved1;
+       __u32 reserved2;
+};
+
+/**
+ * struct ion_heap_query - collection of data about all heaps
+ * @cnt - total number of heaps to be copied
+ * @heaps - buffer to copy heap data
+ */
+struct ion_heap_query {
+       __u32 cnt; /* Total number of heaps to be copied */
+       __u32 reserved0; /* align to 64bits */
+       __u64 heaps; /* buffer to be populated */
+       __u32 reserved1;
+       __u32 reserved2;
+};
+
 #define ION_IOC_MAGIC          'I'
 
 /**
@@ -216,4 +246,13 @@ struct ion_abi_version {
 #define ION_IOC_ABI_VERSION    _IOR(ION_IOC_MAGIC, 8, \
                                        struct ion_abi_version)
 
+/**
+ * DOC: ION_IOC_HEAP_QUERY - information about available heaps
+ *
+ * Takes an ion_heap_query structure and populates information about
+ * available Ion heaps.
+ */
+#define ION_IOC_HEAP_QUERY     _IOWR(ION_IOC_MAGIC, 12, \
+                                       struct ion_heap_query)
+
 #endif /* _UAPI_LINUX_ION_H */
-- 
2.7.4

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