Merge tag 'tee-cleanup-for-5.7' of https://git.linaro.org/people/jens.wiklander/linux-tee into arm/drivers

Cleanup shared memory handing in TEE subsystem
The highlights are:
- Removing redundant or unused fields in struct tee_shm
- Only assign userspace shm IDs for shared memory objects originating from
  user space

* tag 'tee-cleanup-for-5.7' of https://git.linaro.org/people/jens.wiklander/linux-tee:
  tee: tee_shm_op_mmap(): use TEE_SHM_USER_MAPPED
  tee: remove redundant teedev in struct tee_shm
  tee: don't assign shm id for private shms
  tee: remove unused tee_shm_priv_alloc()
  tee: remove linked list of struct tee_shm

Link: https://lore.kernel.org/r/20200228140925.GA12393@jade
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

3 files changed, 26 insertions, 63 deletions

diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c
index 37d22e39fd8d..6aec502c495c 100644
--- a/drivers/tee/tee_core.c
+++ b/drivers/tee/tee_core.c
@@ -44,7 +44,6 @@ static struct tee_context *teedev_open(struct tee_device *teedev)
 
 	kref_init(&ctx->refcount);
 	ctx->teedev = teedev;
-	INIT_LIST_HEAD(&ctx->list_shm);
 	rc = teedev->desc->ops->open(ctx);
 	if (rc)
 		goto err;
diff --git a/drivers/tee/tee_private.h b/drivers/tee/tee_private.h
index f797171f0434..e55204df31ce 100644
--- a/drivers/tee/tee_private.h
+++ b/drivers/tee/tee_private.h
@@ -37,7 +37,8 @@ struct tee_shm_pool {
  * @num_users:	number of active users of this device
  * @c_no_user:	completion used when unregistering the device
  * @mutex:	mutex protecting @num_users and @idr
- * @idr:	register of shared memory object allocated on this device
+ * @idr:	register of user space shared memory objects allocated or
+ *		registered on this device
  * @pool:	shared memory pool
  */
 struct tee_device {
diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
index 937ac5aaa6d8..bd679b72bd05 100644
--- a/drivers/tee/tee_shm.c
+++ b/drivers/tee/tee_shm.c
@@ -13,13 +13,13 @@
 
 static void tee_shm_release(struct tee_shm *shm)
 {
-	struct tee_device *teedev = shm->teedev;
+	struct tee_device *teedev = shm->ctx->teedev;
 
-	mutex_lock(&teedev->mutex);
-	idr_remove(&teedev->idr, shm->id);
-	if (shm->ctx)
-		list_del(&shm->link);
-	mutex_unlock(&teedev->mutex);
+	if (shm->flags & TEE_SHM_DMA_BUF) {
+		mutex_lock(&teedev->mutex);
+		idr_remove(&teedev->idr, shm->id);
+		mutex_unlock(&teedev->mutex);
+	}
 
 	if (shm->flags & TEE_SHM_POOL) {
 		struct tee_shm_pool_mgr *poolm;
@@ -44,8 +44,7 @@ static void tee_shm_release(struct tee_shm *shm)
 		kfree(shm->pages);
 	}
 
-	if (shm->ctx)
-		teedev_ctx_put(shm->ctx);
+	teedev_ctx_put(shm->ctx);
 
 	kfree(shm);
 
@@ -77,7 +76,7 @@ static int tee_shm_op_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
 	size_t size = vma->vm_end - vma->vm_start;
 
 	/* Refuse sharing shared memory provided by application */
-	if (shm->flags & TEE_SHM_REGISTER)
+	if (shm->flags & TEE_SHM_USER_MAPPED)
 		return -EINVAL;
 
 	return remap_pfn_range(vma, vma->vm_start, shm->paddr >> PAGE_SHIFT,
@@ -91,20 +90,14 @@ static const struct dma_buf_ops tee_shm_dma_buf_ops = {
 	.mmap = tee_shm_op_mmap,
 };
 
-static struct tee_shm *__tee_shm_alloc(struct tee_context *ctx,
-				       struct tee_device *teedev,
-				       size_t size, u32 flags)
+struct tee_shm *tee_shm_alloc(struct tee_context *ctx, size_t size, u32 flags)
 {
+	struct tee_device *teedev = ctx->teedev;
 	struct tee_shm_pool_mgr *poolm = NULL;
 	struct tee_shm *shm;
 	void *ret;
 	int rc;
 
-	if (ctx && ctx->teedev != teedev) {
-		dev_err(teedev->dev.parent, "ctx and teedev mismatch\n");
-		return ERR_PTR(-EINVAL);
-	}
-
 	if (!(flags & TEE_SHM_MAPPED)) {
 		dev_err(teedev->dev.parent,
 			"only mapped allocations supported\n");
@@ -132,7 +125,6 @@ static struct tee_shm *__tee_shm_alloc(struct tee_context *ctx,
 	}
 
 	shm->flags = flags | TEE_SHM_POOL;
-	shm->teedev = teedev;
 	shm->ctx = ctx;
 	if (flags & TEE_SHM_DMA_BUF)
 		poolm = teedev->pool->dma_buf_mgr;
@@ -145,17 +137,18 @@ static struct tee_shm *__tee_shm_alloc(struct tee_context *ctx,
 		goto err_kfree;
 	}
 
-	mutex_lock(&teedev->mutex);
-	shm->id = idr_alloc(&teedev->idr, shm, 1, 0, GFP_KERNEL);
-	mutex_unlock(&teedev->mutex);
-	if (shm->id < 0) {
-		ret = ERR_PTR(shm->id);
-		goto err_pool_free;
-	}
 
 	if (flags & TEE_SHM_DMA_BUF) {
 		DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
 
+		mutex_lock(&teedev->mutex);
+		shm->id = idr_alloc(&teedev->idr, shm, 1, 0, GFP_KERNEL);
+		mutex_unlock(&teedev->mutex);
+		if (shm->id < 0) {
+			ret = ERR_PTR(shm->id);
+			goto err_pool_free;
+		}
+
 		exp_info.ops = &tee_shm_dma_buf_ops;
 		exp_info.size = shm->size;
 		exp_info.flags = O_RDWR;
@@ -168,18 +161,16 @@ static struct tee_shm *__tee_shm_alloc(struct tee_context *ctx,
 		}
 	}
 
-	if (ctx) {
+	if (ctx)
 		teedev_ctx_get(ctx);
-		mutex_lock(&teedev->mutex);
-		list_add_tail(&shm->link, &ctx->list_shm);
-		mutex_unlock(&teedev->mutex);
-	}
 
 	return shm;
 err_rem:
-	mutex_lock(&teedev->mutex);
-	idr_remove(&teedev->idr, shm->id);
-	mutex_unlock(&teedev->mutex);
+	if (flags & TEE_SHM_DMA_BUF) {
+		mutex_lock(&teedev->mutex);
+		idr_remove(&teedev->idr, shm->id);
+		mutex_unlock(&teedev->mutex);
+	}
 err_pool_free:
 	poolm->ops->free(poolm, shm);
 err_kfree:
@@ -188,31 +179,8 @@ err_dev_put:
 	tee_device_put(teedev);
 	return ret;
 }
-
-/**
- * tee_shm_alloc() - Allocate shared memory
- * @ctx:	Context that allocates the shared memory
- * @size:	Requested size of shared memory
- * @flags:	Flags setting properties for the requested shared memory.
- *
- * Memory allocated as global shared memory is automatically freed when the
- * TEE file pointer is closed. The @flags field uses the bits defined by
- * TEE_SHM_* in <linux/tee_drv.h>. TEE_SHM_MAPPED must currently always be
- * set. If TEE_SHM_DMA_BUF global shared memory will be allocated and
- * associated with a dma-buf handle, else driver private memory.
- */
-struct tee_shm *tee_shm_alloc(struct tee_context *ctx, size_t size, u32 flags)
-{
-	return __tee_shm_alloc(ctx, ctx->teedev, size, flags);
-}
 EXPORT_SYMBOL_GPL(tee_shm_alloc);
 
-struct tee_shm *tee_shm_priv_alloc(struct tee_device *teedev, size_t size)
-{
-	return __tee_shm_alloc(NULL, teedev, size, TEE_SHM_MAPPED);
-}
-EXPORT_SYMBOL_GPL(tee_shm_priv_alloc);
-
 struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
 				 size_t length, u32 flags)
 {
@@ -245,7 +213,6 @@ struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
 	}
 
 	shm->flags = flags | TEE_SHM_REGISTER;
-	shm->teedev = teedev;
 	shm->ctx = ctx;
 	shm->id = -1;
 	addr = untagged_addr(addr);
@@ -301,10 +268,6 @@ struct tee_shm *tee_shm_register(struct tee_context *ctx, unsigned long addr,
 		}
 	}
 
-	mutex_lock(&teedev->mutex);
-	list_add_tail(&shm->link, &ctx->list_shm);
-	mutex_unlock(&teedev->mutex);
-
 	return shm;
 err:
 	if (shm) {