Merge tag 'tee-drv-dynamic-shm-for-v4.16' of https://git.linaro.org/people/jens.wiklander/linux-tee into next/drivers

Pull "tee dynamic shm for v4.16" from Jens Wiklander:

This pull request enables dynamic shared memory support in the TEE
subsystem as a whole and in OP-TEE in particular.

Global Platform TEE specification [1] allows client applications
to register part of own memory as a shared buffer between
application and TEE. This allows fast zero-copy communication between
TEE and REE. But current implementation of TEE in Linux does not support
this feature.

Also, current implementation of OP-TEE transport uses fixed size
pre-shared buffer for all communications with OP-TEE OS. This is okay
in the most use cases. But this prevents use of OP-TEE in virtualized
environments, because:
 a) We can't share the same buffer between different virtual machines
 b) Physically contiguous memory as seen by VM can be non-contiguous
    in reality (and as seen by OP-TEE OS) due to second stage of
    MMU translation.
 c) Size of this pre-shared buffer is limited.

So, first part of this pull request adds generic register/unregister
interface to tee subsystem. The second part adds necessary features into
OP-TEE driver, so it can use not only static pre-shared buffer, but
whole RAM to communicate with OP-TEE OS.

This change is backwards compatible allowing older secure world or
user space to work with newer kernels and vice versa.

[1] https://www.globalplatform.org/specificationsdevice.asp

* tag 'tee-drv-dynamic-shm-for-v4.16' of https://git.linaro.org/people/jens.wiklander/linux-tee:
  tee: shm: inline tee_shm_get_id()
  tee: use reference counting for tee_context
  tee: optee: enable dynamic SHM support
  tee: optee: add optee-specific shared pool implementation
  tee: optee: store OP-TEE capabilities in private data
  tee: optee: add registered buffers handling into RPC calls
  tee: optee: add registered shared parameters handling
  tee: optee: add shared buffer registration functions
  tee: optee: add page list manipulation functions
  tee: optee: Update protocol definitions
  tee: shm: add page accessor functions
  tee: shm: add accessors for buffer size and page offset
  tee: add register user memory
  tee: flexible shared memory pool creation

1 files changed, 102 insertions, 63 deletions

diff --git a/drivers/tee/tee_shm_pool.c b/drivers/tee/tee_shm_pool.c
index fb4f8522a526..e6d4b9e4a864 100644
--- a/drivers/tee/tee_shm_pool.c
+++ b/drivers/tee/tee_shm_pool.c
@@ -44,49 +44,18 @@ static void pool_op_gen_free(struct tee_shm_pool_mgr *poolm,
 	shm->kaddr = NULL;
 }
 
+static void pool_op_gen_destroy_poolmgr(struct tee_shm_pool_mgr *poolm)
+{
+	gen_pool_destroy(poolm->private_data);
+	kfree(poolm);
+}
+
 static const struct tee_shm_pool_mgr_ops pool_ops_generic = {
 	.alloc = pool_op_gen_alloc,
 	.free = pool_op_gen_free,
+	.destroy_poolmgr = pool_op_gen_destroy_poolmgr,
 };
 
-static void pool_res_mem_destroy(struct tee_shm_pool *pool)
-{
-	gen_pool_destroy(pool->private_mgr.private_data);
-	gen_pool_destroy(pool->dma_buf_mgr.private_data);
-}
-
-static int pool_res_mem_mgr_init(struct tee_shm_pool_mgr *mgr,
-				 struct tee_shm_pool_mem_info *info,
-				 int min_alloc_order)
-{
-	size_t page_mask = PAGE_SIZE - 1;
-	struct gen_pool *genpool = NULL;
-	int rc;
-
-	/*
-	 * Start and end must be page aligned
-	 */
-	if ((info->vaddr & page_mask) || (info->paddr & page_mask) ||
-	    (info->size & page_mask))
-		return -EINVAL;
-
-	genpool = gen_pool_create(min_alloc_order, -1);
-	if (!genpool)
-		return -ENOMEM;
-
-	gen_pool_set_algo(genpool, gen_pool_best_fit, NULL);
-	rc = gen_pool_add_virt(genpool, info->vaddr, info->paddr, info->size,
-			       -1);
-	if (rc) {
-		gen_pool_destroy(genpool);
-		return rc;
-	}
-
-	mgr->private_data = genpool;
-	mgr->ops = &pool_ops_generic;
-	return 0;
-}
-
 /**
  * tee_shm_pool_alloc_res_mem() - Create a shared memory pool from reserved
  * memory range
@@ -104,42 +73,109 @@ struct tee_shm_pool *
 tee_shm_pool_alloc_res_mem(struct tee_shm_pool_mem_info *priv_info,
 			   struct tee_shm_pool_mem_info *dmabuf_info)
 {
-	struct tee_shm_pool *pool = NULL;
-	int ret;
-
-	pool = kzalloc(sizeof(*pool), GFP_KERNEL);
-	if (!pool) {
-		ret = -ENOMEM;
-		goto err;
-	}
+	struct tee_shm_pool_mgr *priv_mgr;
+	struct tee_shm_pool_mgr *dmabuf_mgr;
+	void *rc;
 
 	/*
 	 * Create the pool for driver private shared memory
 	 */
-	ret = pool_res_mem_mgr_init(&pool->private_mgr, priv_info,
-				    3 /* 8 byte aligned */);
-	if (ret)
-		goto err;
+	rc = tee_shm_pool_mgr_alloc_res_mem(priv_info->vaddr, priv_info->paddr,
+					    priv_info->size,
+					    3 /* 8 byte aligned */);
+	if (IS_ERR(rc))
+		return rc;
+	priv_mgr = rc;
 
 	/*
 	 * Create the pool for dma_buf shared memory
 	 */
-	ret = pool_res_mem_mgr_init(&pool->dma_buf_mgr, dmabuf_info,
-				    PAGE_SHIFT);
-	if (ret)
+	rc = tee_shm_pool_mgr_alloc_res_mem(dmabuf_info->vaddr,
+					    dmabuf_info->paddr,
+					    dmabuf_info->size, PAGE_SHIFT);
+	if (IS_ERR(rc))
+		goto err_free_priv_mgr;
+	dmabuf_mgr = rc;
+
+	rc = tee_shm_pool_alloc(priv_mgr, dmabuf_mgr);
+	if (IS_ERR(rc))
+		goto err_free_dmabuf_mgr;
+
+	return rc;
+
+err_free_dmabuf_mgr:
+	tee_shm_pool_mgr_destroy(dmabuf_mgr);
+err_free_priv_mgr:
+	tee_shm_pool_mgr_destroy(priv_mgr);
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(tee_shm_pool_alloc_res_mem);
+
+struct tee_shm_pool_mgr *tee_shm_pool_mgr_alloc_res_mem(unsigned long vaddr,
+							phys_addr_t paddr,
+							size_t size,
+							int min_alloc_order)
+{
+	const size_t page_mask = PAGE_SIZE - 1;
+	struct tee_shm_pool_mgr *mgr;
+	int rc;
+
+	/* Start and end must be page aligned */
+	if (vaddr & page_mask || paddr & page_mask || size & page_mask)
+		return ERR_PTR(-EINVAL);
+
+	mgr = kzalloc(sizeof(*mgr), GFP_KERNEL);
+	if (!mgr)
+		return ERR_PTR(-ENOMEM);
+
+	mgr->private_data = gen_pool_create(min_alloc_order, -1);
+	if (!mgr->private_data) {
+		rc = -ENOMEM;
 		goto err;
+	}
 
-	pool->destroy = pool_res_mem_destroy;
-	return pool;
+	gen_pool_set_algo(mgr->private_data, gen_pool_best_fit, NULL);
+	rc = gen_pool_add_virt(mgr->private_data, vaddr, paddr, size, -1);
+	if (rc) {
+		gen_pool_destroy(mgr->private_data);
+		goto err;
+	}
+
+	mgr->ops = &pool_ops_generic;
+
+	return mgr;
 err:
-	if (ret == -ENOMEM)
-		pr_err("%s: can't allocate memory for res_mem shared memory pool\n", __func__);
-	if (pool && pool->private_mgr.private_data)
-		gen_pool_destroy(pool->private_mgr.private_data);
-	kfree(pool);
-	return ERR_PTR(ret);
+	kfree(mgr);
+
+	return ERR_PTR(rc);
 }
-EXPORT_SYMBOL_GPL(tee_shm_pool_alloc_res_mem);
+EXPORT_SYMBOL_GPL(tee_shm_pool_mgr_alloc_res_mem);
+
+static bool check_mgr_ops(struct tee_shm_pool_mgr *mgr)
+{
+	return mgr && mgr->ops && mgr->ops->alloc && mgr->ops->free &&
+		mgr->ops->destroy_poolmgr;
+}
+
+struct tee_shm_pool *tee_shm_pool_alloc(struct tee_shm_pool_mgr *priv_mgr,
+					struct tee_shm_pool_mgr *dmabuf_mgr)
+{
+	struct tee_shm_pool *pool;
+
+	if (!check_mgr_ops(priv_mgr) || !check_mgr_ops(dmabuf_mgr))
+		return ERR_PTR(-EINVAL);
+
+	pool = kzalloc(sizeof(*pool), GFP_KERNEL);
+	if (!pool)
+		return ERR_PTR(-ENOMEM);
+
+	pool->private_mgr = priv_mgr;
+	pool->dma_buf_mgr = dmabuf_mgr;
+
+	return pool;
+}
+EXPORT_SYMBOL_GPL(tee_shm_pool_alloc);
 
 /**
  * tee_shm_pool_free() - Free a shared memory pool
@@ -150,7 +186,10 @@ EXPORT_SYMBOL_GPL(tee_shm_pool_alloc_res_mem);
  */
 void tee_shm_pool_free(struct tee_shm_pool *pool)
 {
-	pool->destroy(pool);
+	if (pool->private_mgr)
+		tee_shm_pool_mgr_destroy(pool->private_mgr);
+	if (pool->dma_buf_mgr)
+		tee_shm_pool_mgr_destroy(pool->dma_buf_mgr);
 	kfree(pool);
 }
 EXPORT_SYMBOL_GPL(tee_shm_pool_free);