On 10/05/2015 03:11 AM, Benjamin Gaignard wrote:
diff --git a/drivers/smaf/smaf-core.c b/drivers/smaf/smaf-core.c
new file mode 100644
index 0000000..37914e7
--- /dev/null
+++ b/drivers/smaf/smaf-core.c
@@ -0,0 +1,736 @@
+/*
+ * smaf.c
+ *
+ * Copyright (C) Linaro SA 2015
+ * Author: Benjamin Gaignard <benjamin.gaign...@linaro.org> for Linaro.
+ * License terms:  GNU General Public License (GPL), version 2
+ */
+
+#include <linux/device.h>
+#include <linux/dma-buf.h>
+#include <linux/dma-mapping.h>
+#include <linux/fs.h>
+#include <linux/ioctl.h>
+#include <linux/list_sort.h>
+#include <linux/miscdevice.h>
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/smaf.h>
+#include <linux/smaf-allocator.h>
+#include <linux/smaf-secure.h>
+#include <linux/uaccess.h>
+
+struct smaf_handle {
+       struct dma_buf *dmabuf;
+       struct smaf_allocator *allocator;
+       struct dma_buf *db_alloc;
+       size_t length;
+       unsigned int flags;
+       int fd;
+       bool is_secure;
+       void *secure_ctx;
+};
+
+/**
+ * struct smaf_device - smaf device node private data
+ * @misc_dev:  the misc device
+ * @head:      list of allocator
+ * @lock:      list and secure pointer mutex
+ * @secure:    pointer to secure functions helpers
+ */
+struct smaf_device {
+       struct miscdevice misc_dev;
+       struct list_head head;
+       /* list and secure pointer lock*/
+       struct mutex lock;
+       struct smaf_secure *secure;
+};
+
+static struct smaf_device smaf_dev;
+
+/**
+ * smaf_allow_cpu_access return true if CPU can access to memory
+ * if their is no secure module associated to SMAF assume that CPU can get
+ * access to the memory.
+ */
+static bool smaf_allow_cpu_access(struct smaf_handle *handle,
+                                 unsigned long flags)
+{
+       if (!handle->is_secure)
+               return true;
+
+       if (!smaf_dev.secure)
+               return true;
+
+       if (!smaf_dev.secure->allow_cpu_access)
+               return true;
+
+       return smaf_dev.secure->allow_cpu_access(handle->secure_ctx, flags);
+}
+
+static int smaf_grant_access(struct smaf_handle *handle, struct device *dev,
+                            dma_addr_t addr, size_t size,
+                            enum dma_data_direction dir)
+{
+       if (!handle->is_secure)
+               return 0;
+
+       if (!smaf_dev.secure)
+               return -EINVAL;
+
+       if (!smaf_dev.secure->grant_access)
+               return -EINVAL;
+
+       return smaf_dev.secure->grant_access(handle->secure_ctx,
+                                            dev, addr, size, dir);
+}
+
+static void smaf_revoke_access(struct smaf_handle *handle, struct device *dev,
+                              dma_addr_t addr, size_t size,
+                              enum dma_data_direction dir)
+{
+       if (!handle->is_secure)
+               return;
+
+       if (!smaf_dev.secure)
+               return;
+
+       if (!smaf_dev.secure->revoke_access)
+               return;
+
+       smaf_dev.secure->revoke_access(handle->secure_ctx,
+                                      dev, addr, size, dir);
+}
+
+static int smaf_secure_handle(struct smaf_handle *handle)
+{
+       if (handle->is_secure)
+               return 0;
+
+       if (!smaf_dev.secure)
+               return -EINVAL;
+
+       if (!smaf_dev.secure->create_context)
+               return -EINVAL;
+
+       handle->secure_ctx = smaf_dev.secure->create_context();
+
+       if (!handle->secure_ctx)
+               return -EINVAL;
+
+       handle->is_secure = true;
+       return 0;
+}
+
+static int smaf_unsecure_handle(struct smaf_handle *handle)
+{
+       if (!handle->is_secure)
+               return 0;
+
+       if (!smaf_dev.secure)
+               return -EINVAL;
+
+       if (!smaf_dev.secure->destroy_context)
+               return -EINVAL;
+
+       if (smaf_dev.secure->destroy_context(handle->secure_ctx))
+               return -EINVAL;
+
+       handle->secure_ctx = NULL;
+       handle->is_secure = false;
+       return 0;
+}

All these functions need to be protected by a lock, otherwise the
secure state could change. For that matter, I think the smaf_handle
needs a lock to protect its state as well for places like map_dma_buf


<snip>
+static long smaf_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+       switch (cmd) {
+       case SMAF_IOC_CREATE:
+       {
+               struct smaf_create_data data;
+               struct smaf_handle *handle;
+
+               if (copy_from_user(&data, (void __user *)arg, _IOC_SIZE(cmd)))
+                       return -EFAULT;
+
+               handle = smaf_create_handle(data.length, data.flags);
+               if (!handle)
+                       return -EINVAL;
+
+               if (data.name[0]) {
+                       /* user force allocator selection */
+                       if (smaf_select_allocator_by_name(handle->dmabuf,
+                                                         data.name)) {
+                               dma_buf_put(handle->dmabuf);
+                               return -EINVAL;
+                       }
+               }
+
+               handle->fd = dma_buf_fd(handle->dmabuf, data.flags);
+               if (handle->fd < 0) {
+                       dma_buf_put(handle->dmabuf);
+                       return -EINVAL;
+               }
+
+               data.fd = handle->fd;
+               if (copy_to_user((void __user *)arg, &data, _IOC_SIZE(cmd))) {
+                       dma_buf_put(handle->dmabuf);
+                       return -EFAULT;
+               }
+               break;
+       }
+       case SMAF_IOC_GET_SECURE_FLAG:
+       {
+               struct smaf_secure_flag data;
+               struct dma_buf *dmabuf;
+
+               if (copy_from_user(&data, (void __user *)arg, _IOC_SIZE(cmd)))
+                       return -EFAULT;
+
+               dmabuf = dma_buf_get(data.fd);
+               if (!dmabuf)
+                       return -EINVAL;
+
+               data.secure = smaf_is_secure(dmabuf);
+               dma_buf_put(dmabuf);
+
+               if (copy_to_user((void __user *)arg, &data, _IOC_SIZE(cmd)))
+                       return -EFAULT;
+               break;
+       }
+       case SMAF_IOC_SET_SECURE_FLAG:
+       {
+               struct smaf_secure_flag data;
+               struct dma_buf *dmabuf;
+               int ret;
+
+               if (!smaf_dev.secure)
+                       return -EINVAL;
+
+               if (copy_from_user(&data, (void __user *)arg, _IOC_SIZE(cmd)))
+                       return -EFAULT;
+
+               dmabuf = dma_buf_get(data.fd);
+               if (!dmabuf)
+                       return -EINVAL;
+
+               ret = smaf_set_secure(dmabuf, data.secure);
+
+               dma_buf_put(dmabuf);
+
+               if (ret)
+                       return -EINVAL;
+
+               break;
+       }
+       default:
+               return -EINVAL;
+       }
+
+       return 0;
+}

How would you see this tying into something like Ion? It seems like
Ion and SMAF have non-zero over lapping functionality for some things
or that SMAF could be implemented as a heap type. I think my biggest
concern here is that it seems like either Ion or SMAF is going to feel
redundant as an interface.

Thanks,
Laura
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