Merge tag 'tee-prot-dma-buf-for-v6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/jenswi/linux-tee into soc/drivers

TEE protected DMA-bufs for v6.18

- Allocates protected DMA-bufs from a DMA-heap instantiated from the TEE
subsystem.
- The DMA-heap uses a protected memory pool provided by the backend TEE
driver, allowing it to choose how to allocate the protected physical
memory.
- Three use-cases (Secure Video Playback, Trusted UI, and Secure Video
Recording) have been identified so far to serve as examples of what
can be expected.
- The use-cases have predefined DMA-heap names,
"protected,secure-video", "protected,trusted-ui", and
"protected,secure-video-record". The backend driver registers protected
memory pools for the use-cases it supports.

* tag 'tee-prot-dma-buf-for-v6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/jenswi/linux-tee:
optee: smc abi: dynamic protected memory allocation
optee: FF-A: dynamic protected memory allocation
optee: support protected memory allocation
tee: add tee_shm_alloc_dma_mem()
tee: new ioctl to a register tee_shm from a dmabuf file descriptor
tee: refactor params_from_user()
tee: implement protected DMA-heap
dma-buf: dma-heap: export declared functions
optee: sync secure world ABI headers

Link: https://lore.kernel.org/r/20250912101752.GA1453408@rayden
Signed-off-by: Arnd Bergmann <[e-mail]>

drivers/dma-buf/dma-heap.c

···
 #include <linux/dma-buf.h>
 #include <linux/dma-heap.h>
 #include <linux/err.h>
+#include <linux/export.h>
 #include <linux/list.h>
 #include <linux/nospec.h>
 #include <linux/syscalls.h>
···
 {
 	return heap->priv;
 }
+EXPORT_SYMBOL_NS_GPL(dma_heap_get_drvdata, "DMA_BUF_HEAP");
 
 /**
  * dma_heap_get_name - get heap name
···
 {
 	return heap->name;
 }
+EXPORT_SYMBOL_NS_GPL(dma_heap_get_name, "DMA_BUF_HEAP");
 
 /**
  * dma_heap_add - adds a heap to dmabuf heaps
···
 	kfree(heap);
 	return err_ret;
 }
+EXPORT_SYMBOL_NS_GPL(dma_heap_add, "DMA_BUF_HEAP");
 
 static char *dma_heap_devnode(const struct device *dev, umode_t *mode)
 {

drivers/tee/Kconfig

···
 
 if TEE
 
+config TEE_DMABUF_HEAPS
+	bool
+	depends on HAS_DMA && DMABUF_HEAPS
+	default y
+
 source "drivers/tee/optee/Kconfig"
 source "drivers/tee/amdtee/Kconfig"
 source "drivers/tee/tstee/Kconfig"

drivers/tee/Makefile

···
 # SPDX-License-Identifier: GPL-2.0
 obj-$(CONFIG_TEE) += tee.o
 tee-objs += tee_core.o
+tee-objs += tee_heap.o
 tee-objs += tee_shm.o
 tee-objs += tee_shm_pool.o
 obj-$(CONFIG_OPTEE) += optee/

drivers/tee/optee/Kconfig

···
 
 	  Additional documentation on kernel security risks are at
 	  Documentation/tee/op-tee.rst.
+
+config OPTEE_STATIC_PROTMEM_POOL
+	bool
+	depends on HAS_IOMEM && TEE_DMABUF_HEAPS
+	default y

drivers/tee/optee/Makefile

···
 optee-objs += call.o
 optee-objs += notif.o
 optee-objs += rpc.o
+optee-objs += protmem.o
 optee-objs += supp.o
 optee-objs += device.o
 optee-objs += smc_abi.o

drivers/tee/optee/core.c

···
 	return 0;
 }
 
+int optee_set_dma_mask(struct optee *optee, u_int pa_width)
+{
+	u64 mask = DMA_BIT_MASK(min(64, pa_width));
+
+	return dma_coerce_mask_and_coherent(&optee->teedev->dev, mask);
+}
+
 static void optee_bus_scan(struct work_struct *work)
 {
 	WARN_ON(optee_enumerate_devices(PTA_CMD_GET_DEVICES_SUPP));

drivers/tee/optee/ffa_abi.c

···
 	return optee_ffa_yielding_call(ctx, &data, rpc_arg, system_thread);
 }
 
+static int do_call_lend_protmem(struct optee *optee, u64 cookie, u32 use_case)
+{
+	struct optee_shm_arg_entry *entry;
+	struct optee_msg_arg *msg_arg;
+	struct tee_shm *shm;
+	u_int offs;
+	int rc;
+
+	msg_arg = optee_get_msg_arg(optee->ctx, 1, &entry, &shm, &offs);
+	if (IS_ERR(msg_arg))
+		return PTR_ERR(msg_arg);
+
+	msg_arg->cmd = OPTEE_MSG_CMD_ASSIGN_PROTMEM;
+	msg_arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_VALUE_INPUT;
+	msg_arg->params[0].u.value.a = cookie;
+	msg_arg->params[0].u.value.b = use_case;
+
+	rc = optee->ops->do_call_with_arg(optee->ctx, shm, offs, false);
+	if (rc)
+		goto out;
+	if (msg_arg->ret != TEEC_SUCCESS) {
+		rc = -EINVAL;
+		goto out;
+	}
+
+out:
+	optee_free_msg_arg(optee->ctx, entry, offs);
+	return rc;
+}
+
+static int optee_ffa_lend_protmem(struct optee *optee, struct tee_shm *protmem,
+				  u32 *mem_attrs, unsigned int ma_count,
+				  u32 use_case)
+{
+	struct ffa_device *ffa_dev = optee->ffa.ffa_dev;
+	const struct ffa_mem_ops *mem_ops = ffa_dev->ops->mem_ops;
+	const struct ffa_msg_ops *msg_ops = ffa_dev->ops->msg_ops;
+	struct ffa_send_direct_data data;
+	struct ffa_mem_region_attributes *mem_attr;
+	struct ffa_mem_ops_args args = {
+		.use_txbuf = true,
+		.tag = use_case,
+	};
+	struct page *page;
+	struct scatterlist sgl;
+	unsigned int n;
+	int rc;
+
+	mem_attr = kcalloc(ma_count, sizeof(*mem_attr), GFP_KERNEL);
+	for (n = 0; n < ma_count; n++) {
+		mem_attr[n].receiver = mem_attrs[n] & U16_MAX;
+		mem_attr[n].attrs = mem_attrs[n] >> 16;
+	}
+	args.attrs = mem_attr;
+	args.nattrs = ma_count;
+
+	page = phys_to_page(protmem->paddr);
+	sg_init_table(&sgl, 1);
+	sg_set_page(&sgl, page, protmem->size, 0);
+
+	args.sg = &sgl;
+	rc = mem_ops->memory_lend(&args);
+	kfree(mem_attr);
+	if (rc)
+		return rc;
+
+	rc = do_call_lend_protmem(optee, args.g_handle, use_case);
+	if (rc)
+		goto err_reclaim;
+
+	rc = optee_shm_add_ffa_handle(optee, protmem, args.g_handle);
+	if (rc)
+		goto err_unreg;
+
+	protmem->sec_world_id = args.g_handle;
+
+	return 0;
+
+err_unreg:
+	data = (struct ffa_send_direct_data){
+		.data0 = OPTEE_FFA_RELEASE_PROTMEM,
+		.data1 = (u32)args.g_handle,
+		.data2 = (u32)(args.g_handle >> 32),
+	};
+	msg_ops->sync_send_receive(ffa_dev, &data);
+err_reclaim:
+	mem_ops->memory_reclaim(args.g_handle, 0);
+	return rc;
+}
+
+static int optee_ffa_reclaim_protmem(struct optee *optee,
+				     struct tee_shm *protmem)
+{
+	struct ffa_device *ffa_dev = optee->ffa.ffa_dev;
+	const struct ffa_msg_ops *msg_ops = ffa_dev->ops->msg_ops;
+	const struct ffa_mem_ops *mem_ops = ffa_dev->ops->mem_ops;
+	u64 global_handle = protmem->sec_world_id;
+	struct ffa_send_direct_data data = {
+		.data0 = OPTEE_FFA_RELEASE_PROTMEM,
+		.data1 = (u32)global_handle,
+		.data2 = (u32)(global_handle >> 32)
+	};
+	int rc;
+
+	optee_shm_rem_ffa_handle(optee, global_handle);
+	protmem->sec_world_id = 0;
+
+	rc = msg_ops->sync_send_receive(ffa_dev, &data);
+	if (rc)
+		pr_err("Release SHM id 0x%llx rc %d\n", global_handle, rc);
+
+	rc = mem_ops->memory_reclaim(global_handle, 0);
+	if (rc)
+		pr_err("mem_reclaim: 0x%llx %d", global_handle, rc);
+
+	return rc;
+}
+
 /*
  * 6. Driver initialization
  *
···
 	.do_call_with_arg = optee_ffa_do_call_with_arg,
 	.to_msg_param = optee_ffa_to_msg_param,
 	.from_msg_param = optee_ffa_from_msg_param,
+	.lend_protmem = optee_ffa_lend_protmem,
+	.reclaim_protmem = optee_ffa_reclaim_protmem,
 };
 
 static void optee_ffa_remove(struct ffa_device *ffa_dev)
···
 	return rc;
 }
 
+static int optee_ffa_protmem_pool_init(struct optee *optee, u32 sec_caps)
+{
+	enum tee_dma_heap_id id = TEE_DMA_HEAP_SECURE_VIDEO_PLAY;
+	struct tee_protmem_pool *pool;
+	int rc = 0;
+
+	if (sec_caps & OPTEE_FFA_SEC_CAP_PROTMEM) {
+		pool = optee_protmem_alloc_dyn_pool(optee, id);
+		if (IS_ERR(pool))
+			return PTR_ERR(pool);
+
+		rc = tee_device_register_dma_heap(optee->teedev, id, pool);
+		if (rc)
+			pool->ops->destroy_pool(pool);
+	}
+
+	return rc;
+}
+
 static int optee_ffa_probe(struct ffa_device *ffa_dev)
 {
 	const struct ffa_notifier_ops *notif_ops;
···
 				  optee);
 	if (IS_ERR(teedev)) {
 		rc = PTR_ERR(teedev);
-		goto err_free_pool;
+		goto err_free_shm_pool;
 	}
 	optee->teedev = teedev;
 
···
 			       rc);
 	}
 
+	if (optee_ffa_protmem_pool_init(optee, sec_caps))
+		pr_info("Protected memory service not available\n");
+
 	rc = optee_enumerate_devices(PTA_CMD_GET_DEVICES);
 	if (rc)
 		goto err_unregister_devices;
···
 	tee_device_unregister(optee->supp_teedev);
 err_unreg_teedev:
 	tee_device_unregister(optee->teedev);
-err_free_pool:
+err_free_shm_pool:
 	tee_shm_pool_free(pool);
 err_free_optee:
 	kfree(optee);

drivers/tee/optee/optee_ffa.h

···
  *                   as the second MSG arg struct for
  *                   OPTEE_FFA_YIELDING_CALL_WITH_ARG.
  *        Bit[31:8]: Reserved (MBZ)
- * w5:	  Bitfield of secure world capabilities OPTEE_FFA_SEC_CAP_* below,
+ * w5:	  Bitfield of OP-TEE capabilities OPTEE_FFA_SEC_CAP_*
  * w6:	  The maximum secure world notification number
  * w7:	  Not used (MBZ)
  */
···
 #define OPTEE_FFA_SEC_CAP_ASYNC_NOTIF	BIT(1)
 /* OP-TEE supports probing for RPMB device if needed */
 #define OPTEE_FFA_SEC_CAP_RPMB_PROBE	BIT(2)
+/* OP-TEE supports Protected Memory for secure data path */
+#define OPTEE_FFA_SEC_CAP_PROTMEM	BIT(3)
 
 #define OPTEE_FFA_EXCHANGE_CAPABILITIES OPTEE_FFA_BLOCKING_CALL(2)
 
···
  *
  * Return register usage:
  * w3:    Error code, 0 on success
- * w4-w7: Note used (MBZ)
+ * w4-w7: Not used (MBZ)
  */
 #define OPTEE_FFA_UNREGISTER_SHM	OPTEE_FFA_BLOCKING_CALL(3)
 
···
  * Call register usage:
  * w3:    Service ID, OPTEE_FFA_ENABLE_ASYNC_NOTIF
  * w4:	  Notification value to request bottom half processing, should be
- *	  less than OPTEE_FFA_MAX_ASYNC_NOTIF_VALUE.
+ *	  less than OPTEE_FFA_MAX_ASYNC_NOTIF_VALUE
  * w5-w7: Not used (MBZ)
+ *
+ * Return register usage:
+ * w3:    Error code, 0 on success
+ * w4-w7: Not used (MBZ)
+ */
+#define OPTEE_FFA_ENABLE_ASYNC_NOTIF	OPTEE_FFA_BLOCKING_CALL(5)
+
+#define OPTEE_FFA_MAX_ASYNC_NOTIF_VALUE	64
+
+/*
+ * Release Protected memory
+ *
+ * Call register usage:
+ * w3:    Service ID, OPTEE_FFA_RECLAIM_PROTMEM
+ * w4:    Shared memory handle, lower bits
+ * w5:    Shared memory handle, higher bits
+ * w6-w7: Not used (MBZ)
  *
  * Return register usage:
  * w3:    Error code, 0 on success
  * w4-w7: Note used (MBZ)
  */
-#define OPTEE_FFA_ENABLE_ASYNC_NOTIF	OPTEE_FFA_BLOCKING_CALL(5)
-
-#define OPTEE_FFA_MAX_ASYNC_NOTIF_VALUE 64
+#define OPTEE_FFA_RELEASE_PROTMEM	OPTEE_FFA_BLOCKING_CALL(8)
 
 /*
  * Call with struct optee_msg_arg as argument in the supplied shared memory

drivers/tee/optee/optee_msg.h

···
 };
 
 /**
- * struct optee_msg_param_fmem - ffa memory reference parameter
+ * struct optee_msg_param_fmem - FF-A memory reference parameter
  * @offs_lower:	   Lower bits of offset into shared memory reference
  * @offs_upper:	   Upper bits of offset into shared memory reference
  * @internal_offs: Internal offset into the first page of shared memory
  *		   reference
  * @size:	   Size of the buffer
- * @global_id:	   Global identifier of Shared memory
+ * @global_id:	   Global identifier of the shared memory
  */
 struct optee_msg_param_fmem {
 	u32 offs_low;
···
  * @attr:	attributes
  * @tmem:	parameter by temporary memory reference
  * @rmem:	parameter by registered memory reference
- * @fmem:	parameter by ffa registered memory reference
+ * @fmem:	parameter by FF-A registered memory reference
  * @value:	parameter by opaque value
  * @octets:	parameter by octet string
  *
···
 #define OPTEE_MSG_FUNCID_GET_OS_REVISION	0x0001
 
 /*
+ * Values used in OPTEE_MSG_CMD_LEND_PROTMEM below
+ * OPTEE_MSG_PROTMEM_RESERVED		Reserved
+ * OPTEE_MSG_PROTMEM_SECURE_VIDEO_PLAY	Secure Video Playback
+ * OPTEE_MSG_PROTMEM_TRUSTED_UI		Trused UI
+ * OPTEE_MSG_PROTMEM_SECURE_VIDEO_RECORD	Secure Video Recording
+ */
+#define OPTEE_MSG_PROTMEM_RESERVED		0
+#define OPTEE_MSG_PROTMEM_SECURE_VIDEO_PLAY	1
+#define OPTEE_MSG_PROTMEM_TRUSTED_UI		2
+#define OPTEE_MSG_PROTMEM_SECURE_VIDEO_RECORD	3
+
+/*
  * Do a secure call with struct optee_msg_arg as argument
  * The OPTEE_MSG_CMD_* below defines what goes in struct optee_msg_arg::cmd
  *
···
  * OPTEE_MSG_CMD_STOP_ASYNC_NOTIF informs secure world that from now is
  * normal world unable to process asynchronous notifications. Typically
  * used when the driver is shut down.
+ *
+ * OPTEE_MSG_CMD_LEND_PROTMEM lends protected memory. The passed normal
+ * physical memory is protected from normal world access. The memory
+ * should be unmapped prior to this call since it becomes inaccessible
+ * during the request.
+ * Parameters are passed as:
+ * [in] param[0].attr			OPTEE_MSG_ATTR_TYPE_VALUE_INPUT
+ * [in] param[0].u.value.a		OPTEE_MSG_PROTMEM_* defined above
+ * [in] param[1].attr			OPTEE_MSG_ATTR_TYPE_TMEM_INPUT
+ * [in] param[1].u.tmem.buf_ptr		physical address
+ * [in] param[1].u.tmem.size		size
+ * [in] param[1].u.tmem.shm_ref		holds protected memory reference
+ *
+ * OPTEE_MSG_CMD_RECLAIM_PROTMEM reclaims a previously lent protected
+ * memory reference. The physical memory is accessible by the normal world
+ * after this function has return and can be mapped again. The information
+ * is passed as:
+ * [in] param[0].attr			OPTEE_MSG_ATTR_TYPE_VALUE_INPUT
+ * [in] param[0].u.value.a		holds protected memory cookie
+ *
+ * OPTEE_MSG_CMD_GET_PROTMEM_CONFIG get configuration for a specific
+ * protected memory use case. Parameters are passed as:
+ * [in] param[0].attr			OPTEE_MSG_ATTR_TYPE_VALUE_INOUT
+ * [in] param[0].value.a		OPTEE_MSG_PROTMEM_*
+ * [in] param[1].attr			OPTEE_MSG_ATTR_TYPE_{R,F}MEM_OUTPUT
+ * [in] param[1].u.{r,f}mem		Buffer or NULL
+ * [in] param[1].u.{r,f}mem.size	Provided size of buffer or 0 for query
+ * output for the protected use case:
+ * [out] param[0].value.a		Minimal size of protected memory
+ * [out] param[0].value.b		Required alignment of size and start of
+ *					protected memory
+ * [out] param[0].value.c               PA width, max 64
+ * [out] param[1].{r,f}mem.size		Size of output data
+ * [out] param[1].{r,f}mem		If non-NULL, contains an array of
+ *					uint32_t memory attributes that must be
+ *					included when lending memory for this
+ *					use case
+ *
+ * OPTEE_MSG_CMD_ASSIGN_PROTMEM assigns use-case to protected memory
+ * previously lent using the FFA_LEND framework ABI. Parameters are passed
+ * as:
+ * [in] param[0].attr			OPTEE_MSG_ATTR_TYPE_VALUE_INPUT
+ * [in] param[0].u.value.a		holds protected memory cookie
+ * [in] param[0].u.value.b		OPTEE_MSG_PROTMEM_* defined above
  */
-#define OPTEE_MSG_CMD_OPEN_SESSION	0
-#define OPTEE_MSG_CMD_INVOKE_COMMAND	1
-#define OPTEE_MSG_CMD_CLOSE_SESSION	2
-#define OPTEE_MSG_CMD_CANCEL		3
-#define OPTEE_MSG_CMD_REGISTER_SHM	4
-#define OPTEE_MSG_CMD_UNREGISTER_SHM	5
-#define OPTEE_MSG_CMD_DO_BOTTOM_HALF	6
-#define OPTEE_MSG_CMD_STOP_ASYNC_NOTIF	7
-#define OPTEE_MSG_FUNCID_CALL_WITH_ARG	0x0004
+#define OPTEE_MSG_CMD_OPEN_SESSION		0
+#define OPTEE_MSG_CMD_INVOKE_COMMAND		1
+#define OPTEE_MSG_CMD_CLOSE_SESSION		2
+#define OPTEE_MSG_CMD_CANCEL			3
+#define OPTEE_MSG_CMD_REGISTER_SHM		4
+#define OPTEE_MSG_CMD_UNREGISTER_SHM		5
+#define OPTEE_MSG_CMD_DO_BOTTOM_HALF		6
+#define OPTEE_MSG_CMD_STOP_ASYNC_NOTIF		7
+#define OPTEE_MSG_CMD_LEND_PROTMEM		8
+#define OPTEE_MSG_CMD_RECLAIM_PROTMEM		9
+#define OPTEE_MSG_CMD_GET_PROTMEM_CONFIG	10
+#define OPTEE_MSG_CMD_ASSIGN_PROTMEM		11
+#define OPTEE_MSG_FUNCID_CALL_WITH_ARG		0x0004
 
 #endif /* _OPTEE_MSG_H */

drivers/tee/optee/optee_private.h

···
  * @do_call_with_arg:	enters OP-TEE in secure world
  * @to_msg_param:	converts from struct tee_param to OPTEE_MSG parameters
  * @from_msg_param:	converts from OPTEE_MSG parameters to struct tee_param
+ * @lend_protmem:	lends physically contiguous memory as restricted
+ *			memory, inaccessible by the kernel
+ * @reclaim_protmem:	reclaims restricted memory previously lent with
+ *			@lend_protmem() and makes it accessible by the
+ *			kernel again
  *
  * These OPs are only supposed to be used internally in the OP-TEE driver
- * as a way of abstracting the different methogs of entering OP-TEE in
+ * as a way of abstracting the different methods of entering OP-TEE in
  * secure world.
  */
 struct optee_ops {
···
 	int (*from_msg_param)(struct optee *optee, struct tee_param *params,
 			      size_t num_params,
 			      const struct optee_msg_param *msg_params);
+	int (*lend_protmem)(struct optee *optee, struct tee_shm *protmem,
+			    u32 *mem_attr, unsigned int ma_count,
+			    u32 use_case);
+	int (*reclaim_protmem)(struct optee *optee, struct tee_shm *protmem);
 };
 
 /**
···
 
 extern struct blocking_notifier_head optee_rpmb_intf_added;
 
+int optee_set_dma_mask(struct optee *optee, u_int pa_width);
+
 int optee_notif_init(struct optee *optee, u_int max_key);
 void optee_notif_uninit(struct optee *optee);
 int optee_notif_wait(struct optee *optee, u_int key, u32 timeout);
···
 void optee_supp_init(struct optee_supp *supp);
 void optee_supp_uninit(struct optee_supp *supp);
 void optee_supp_release(struct optee_supp *supp);
+struct tee_protmem_pool *optee_protmem_alloc_dyn_pool(struct optee *optee,
+						      enum tee_dma_heap_id id);
 
 int optee_supp_recv(struct tee_context *ctx, u32 *func, u32 *num_params,
 		    struct tee_param *param);

drivers/tee/optee/optee_smc.h

···
 #define OPTEE_SMC_SEC_CAP_HAVE_RESERVED_SHM	BIT(0)
 /* Secure world can communicate via previously unregistered shared memory */
 #define OPTEE_SMC_SEC_CAP_UNREGISTERED_SHM	BIT(1)
-
 /*
  * Secure world supports commands "register/unregister shared memory",
  * secure world accepts command buffers located in any parts of non-secure RAM
···
 #define OPTEE_SMC_SEC_CAP_RPC_ARG		BIT(6)
 /* Secure world supports probing for RPMB device if needed */
 #define OPTEE_SMC_SEC_CAP_RPMB_PROBE		BIT(7)
+/* Secure world supports protected memory */
+#define OPTEE_SMC_SEC_CAP_PROTMEM		BIT(8)
+/* Secure world supports dynamic protected memory */
+#define OPTEE_SMC_SEC_CAP_DYNAMIC_PROTMEM	BIT(9)
 
 #define OPTEE_SMC_FUNCID_EXCHANGE_CAPABILITIES	9
 #define OPTEE_SMC_EXCHANGE_CAPABILITIES \
···
 
 /* See OPTEE_SMC_CALL_WITH_REGD_ARG above */
 #define OPTEE_SMC_FUNCID_CALL_WITH_REGD_ARG	19
+/*
+ * Get protected memory config
+ *
+ * Returns the protected memory config.
+ *
+ * Call register usage:
+ * a0   SMC Function ID, OPTEE_SMC_GET_PROTMEM_CONFIG
+ * a2-6	Not used, must be zero
+ * a7	Hypervisor Client ID register
+ *
+ * Have config return register usage:
+ * a0	OPTEE_SMC_RETURN_OK
+ * a1	Physical address of start of protected memory
+ * a2	Size of protected memory
+ * a3	PA width, max 64
+ * a4-7	Preserved
+ *
+ * Not available register usage:
+ * a0	OPTEE_SMC_RETURN_ENOTAVAIL
+ * a1-3 Not used
+ * a4-7	Preserved
+ */
+#define OPTEE_SMC_FUNCID_GET_PROTMEM_CONFIG		20
+#define OPTEE_SMC_GET_PROTMEM_CONFIG \
+	OPTEE_SMC_FAST_CALL_VAL(OPTEE_SMC_FUNCID_GET_PROTMEM_CONFIG)
+
+struct optee_smc_get_protmem_config_result {
+	unsigned long status;
+	unsigned long start;
+	unsigned long size;
+	unsigned long pa_width;
+};
 
 /*
  * Resume from RPC (for example after processing a foreign interrupt)

drivers/tee/optee/protmem.c

···
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2025, Linaro Limited
+ */
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/errno.h>
+#include <linux/genalloc.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/tee_core.h>
+#include <linux/types.h>
+#include "optee_private.h"
+
+struct optee_protmem_dyn_pool {
+	struct tee_protmem_pool pool;
+	struct gen_pool *gen_pool;
+	struct optee *optee;
+	size_t page_count;
+	u32 *mem_attrs;
+	u_int mem_attr_count;
+	refcount_t refcount;
+	u32 use_case;
+	struct tee_shm *protmem;
+	/* Protects when initializing and tearing down this struct */
+	struct mutex mutex;
+};
+
+static struct optee_protmem_dyn_pool *
+to_protmem_dyn_pool(struct tee_protmem_pool *pool)
+{
+	return container_of(pool, struct optee_protmem_dyn_pool, pool);
+}
+
+static int init_dyn_protmem(struct optee_protmem_dyn_pool *rp)
+{
+	int rc;
+
+	rp->protmem = tee_shm_alloc_dma_mem(rp->optee->ctx, rp->page_count);
+	if (IS_ERR(rp->protmem)) {
+		rc = PTR_ERR(rp->protmem);
+		goto err_null_protmem;
+	}
+
+	/*
+	 * TODO unmap the memory range since the physical memory will
+	 * become inaccesible after the lend_protmem() call.
+	 *
+	 * If the platform supports a hypervisor at EL2, it will unmap the
+	 * intermediate physical memory for us and stop cache pre-fetch of
+	 * the memory.
+	 */
+	rc = rp->optee->ops->lend_protmem(rp->optee, rp->protmem,
+					  rp->mem_attrs,
+					  rp->mem_attr_count, rp->use_case);
+	if (rc)
+		goto err_put_shm;
+	rp->protmem->flags |= TEE_SHM_DYNAMIC;
+
+	rp->gen_pool = gen_pool_create(PAGE_SHIFT, -1);
+	if (!rp->gen_pool) {
+		rc = -ENOMEM;
+		goto err_reclaim;
+	}
+
+	rc = gen_pool_add(rp->gen_pool, rp->protmem->paddr,
+			  rp->protmem->size, -1);
+	if (rc)
+		goto err_free_pool;
+
+	refcount_set(&rp->refcount, 1);
+	return 0;
+
+err_free_pool:
+	gen_pool_destroy(rp->gen_pool);
+	rp->gen_pool = NULL;
+err_reclaim:
+	rp->optee->ops->reclaim_protmem(rp->optee, rp->protmem);
+err_put_shm:
+	tee_shm_put(rp->protmem);
+err_null_protmem:
+	rp->protmem = NULL;
+	return rc;
+}
+
+static int get_dyn_protmem(struct optee_protmem_dyn_pool *rp)
+{
+	int rc = 0;
+
+	if (!refcount_inc_not_zero(&rp->refcount)) {
+		mutex_lock(&rp->mutex);
+		if (rp->gen_pool) {
+			/*
+			 * Another thread has already initialized the pool
+			 * before us, or the pool was just about to be torn
+			 * down. Either way we only need to increase the
+			 * refcount and we're done.
+			 */
+			refcount_inc(&rp->refcount);
+		} else {
+			rc = init_dyn_protmem(rp);
+		}
+		mutex_unlock(&rp->mutex);
+	}
+
+	return rc;
+}
+
+static void release_dyn_protmem(struct optee_protmem_dyn_pool *rp)
+{
+	gen_pool_destroy(rp->gen_pool);
+	rp->gen_pool = NULL;
+
+	rp->optee->ops->reclaim_protmem(rp->optee, rp->protmem);
+	rp->protmem->flags &= ~TEE_SHM_DYNAMIC;
+
+	WARN(refcount_read(&rp->protmem->refcount) != 1, "Unexpected refcount");
+	tee_shm_put(rp->protmem);
+	rp->protmem = NULL;
+}
+
+static void put_dyn_protmem(struct optee_protmem_dyn_pool *rp)
+{
+	if (refcount_dec_and_test(&rp->refcount)) {
+		mutex_lock(&rp->mutex);
+		if (rp->gen_pool)
+			release_dyn_protmem(rp);
+		mutex_unlock(&rp->mutex);
+	}
+}
+
+static int protmem_pool_op_dyn_alloc(struct tee_protmem_pool *pool,
+				     struct sg_table *sgt, size_t size,
+				     size_t *offs)
+{
+	struct optee_protmem_dyn_pool *rp = to_protmem_dyn_pool(pool);
+	size_t sz = ALIGN(size, PAGE_SIZE);
+	phys_addr_t pa;
+	int rc;
+
+	rc = get_dyn_protmem(rp);
+	if (rc)
+		return rc;
+
+	pa = gen_pool_alloc(rp->gen_pool, sz);
+	if (!pa) {
+		rc = -ENOMEM;
+		goto err_put;
+	}
+
+	rc = sg_alloc_table(sgt, 1, GFP_KERNEL);
+	if (rc)
+		goto err_free;
+
+	sg_set_page(sgt->sgl, phys_to_page(pa), size, 0);
+	*offs = pa - rp->protmem->paddr;
+
+	return 0;
+err_free:
+	gen_pool_free(rp->gen_pool, pa, size);
+err_put:
+	put_dyn_protmem(rp);
+
+	return rc;
+}
+
+static void protmem_pool_op_dyn_free(struct tee_protmem_pool *pool,
+				     struct sg_table *sgt)
+{
+	struct optee_protmem_dyn_pool *rp = to_protmem_dyn_pool(pool);
+	struct scatterlist *sg;
+	int i;
+
+	for_each_sgtable_sg(sgt, sg, i)
+		gen_pool_free(rp->gen_pool, sg_phys(sg), sg->length);
+	sg_free_table(sgt);
+	put_dyn_protmem(rp);
+}
+
+static int protmem_pool_op_dyn_update_shm(struct tee_protmem_pool *pool,
+					  struct sg_table *sgt, size_t offs,
+					  struct tee_shm *shm,
+					  struct tee_shm **parent_shm)
+{
+	struct optee_protmem_dyn_pool *rp = to_protmem_dyn_pool(pool);
+
+	*parent_shm = rp->protmem;
+
+	return 0;
+}
+
+static void pool_op_dyn_destroy_pool(struct tee_protmem_pool *pool)
+{
+	struct optee_protmem_dyn_pool *rp = to_protmem_dyn_pool(pool);
+
+	mutex_destroy(&rp->mutex);
+	kfree(rp);
+}
+
+static struct tee_protmem_pool_ops protmem_pool_ops_dyn = {
+	.alloc = protmem_pool_op_dyn_alloc,
+	.free = protmem_pool_op_dyn_free,
+	.update_shm = protmem_pool_op_dyn_update_shm,
+	.destroy_pool = pool_op_dyn_destroy_pool,
+};
+
+static int get_protmem_config(struct optee *optee, u32 use_case,
+			      size_t *min_size, u_int *pa_width,
+			      u32 *mem_attrs, u_int *ma_count)
+{
+	struct tee_param params[2] = {
+		[0] = {
+			.attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT,
+			.u.value.a = use_case,
+		},
+		[1] = {
+			.attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT,
+		},
+	};
+	struct optee_shm_arg_entry *entry;
+	struct tee_shm *shm_param = NULL;
+	struct optee_msg_arg *msg_arg;
+	struct tee_shm *shm;
+	u_int offs;
+	int rc;
+
+	if (mem_attrs && *ma_count) {
+		params[1].u.memref.size = *ma_count * sizeof(*mem_attrs);
+		shm_param = tee_shm_alloc_priv_buf(optee->ctx,
+						   params[1].u.memref.size);
+		if (IS_ERR(shm_param))
+			return PTR_ERR(shm_param);
+		params[1].u.memref.shm = shm_param;
+	}
+
+	msg_arg = optee_get_msg_arg(optee->ctx, ARRAY_SIZE(params), &entry,
+				    &shm, &offs);
+	if (IS_ERR(msg_arg)) {
+		rc = PTR_ERR(msg_arg);
+		goto out_free_shm;
+	}
+	msg_arg->cmd = OPTEE_MSG_CMD_GET_PROTMEM_CONFIG;
+
+	rc = optee->ops->to_msg_param(optee, msg_arg->params,
+				      ARRAY_SIZE(params), params);
+	if (rc)
+		goto out_free_msg;
+
+	rc = optee->ops->do_call_with_arg(optee->ctx, shm, offs, false);
+	if (rc)
+		goto out_free_msg;
+	if (msg_arg->ret && msg_arg->ret != TEEC_ERROR_SHORT_BUFFER) {
+		rc = -EINVAL;
+		goto out_free_msg;
+	}
+
+	rc = optee->ops->from_msg_param(optee, params, ARRAY_SIZE(params),
+					msg_arg->params);
+	if (rc)
+		goto out_free_msg;
+
+	if (!msg_arg->ret && mem_attrs &&
+	    *ma_count < params[1].u.memref.size / sizeof(*mem_attrs)) {
+		rc = -EINVAL;
+		goto out_free_msg;
+	}
+
+	*min_size = params[0].u.value.a;
+	*pa_width = params[0].u.value.c;
+	*ma_count = params[1].u.memref.size / sizeof(*mem_attrs);
+
+	if (msg_arg->ret == TEEC_ERROR_SHORT_BUFFER) {
+		rc = -ENOSPC;
+		goto out_free_msg;
+	}
+
+	if (mem_attrs)
+		memcpy(mem_attrs, tee_shm_get_va(shm_param, 0),
+		       params[1].u.memref.size);
+
+out_free_msg:
+	optee_free_msg_arg(optee->ctx, entry, offs);
+out_free_shm:
+	if (shm_param)
+		tee_shm_free(shm_param);
+	return rc;
+}
+
+struct tee_protmem_pool *optee_protmem_alloc_dyn_pool(struct optee *optee,
+						      enum tee_dma_heap_id id)
+{
+	struct optee_protmem_dyn_pool *rp;
+	size_t min_size;
+	u_int pa_width;
+	int rc;
+
+	rp = kzalloc(sizeof(*rp), GFP_KERNEL);
+	if (!rp)
+		return ERR_PTR(-ENOMEM);
+	rp->use_case = id;
+
+	rc = get_protmem_config(optee, id, &min_size, &pa_width, NULL,
+				&rp->mem_attr_count);
+	if (rc) {
+		if (rc != -ENOSPC)
+			goto err;
+		rp->mem_attrs = kcalloc(rp->mem_attr_count,
+					sizeof(*rp->mem_attrs), GFP_KERNEL);
+		if (!rp->mem_attrs) {
+			rc = -ENOMEM;
+			goto err;
+		}
+		rc = get_protmem_config(optee, id, &min_size, &pa_width,
+					rp->mem_attrs, &rp->mem_attr_count);
+		if (rc)
+			goto err_kfree_eps;
+	}
+
+	rc = optee_set_dma_mask(optee, pa_width);
+	if (rc)
+		goto err_kfree_eps;
+
+	rp->pool.ops = &protmem_pool_ops_dyn;
+	rp->optee = optee;
+	rp->page_count = min_size / PAGE_SIZE;
+	mutex_init(&rp->mutex);
+
+	return &rp->pool;
+
+err_kfree_eps:
+	kfree(rp->mem_attrs);
+err:
+	kfree(rp);
+	return ERR_PTR(rc);
+}

drivers/tee/optee/smc_abi.c

···
 	return rc;
 }
 
+static int optee_smc_lend_protmem(struct optee *optee, struct tee_shm *protmem,
+				  u32 *mem_attrs, unsigned int ma_count,
+				  u32 use_case)
+{
+	struct optee_shm_arg_entry *entry;
+	struct optee_msg_arg *msg_arg;
+	struct tee_shm *shm;
+	u_int offs;
+	int rc;
+
+	msg_arg = optee_get_msg_arg(optee->ctx, 2, &entry, &shm, &offs);
+	if (IS_ERR(msg_arg))
+		return PTR_ERR(msg_arg);
+
+	msg_arg->cmd = OPTEE_MSG_CMD_LEND_PROTMEM;
+	msg_arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_VALUE_INPUT;
+	msg_arg->params[0].u.value.a = use_case;
+	msg_arg->params[1].attr = OPTEE_MSG_ATTR_TYPE_TMEM_INPUT;
+	msg_arg->params[1].u.tmem.buf_ptr = protmem->paddr;
+	msg_arg->params[1].u.tmem.size = protmem->size;
+	msg_arg->params[1].u.tmem.shm_ref = (u_long)protmem;
+
+	rc = optee->ops->do_call_with_arg(optee->ctx, shm, offs, false);
+	if (rc)
+		goto out;
+	if (msg_arg->ret != TEEC_SUCCESS) {
+		rc = -EINVAL;
+		goto out;
+	}
+	protmem->sec_world_id = (u_long)protmem;
+
+out:
+	optee_free_msg_arg(optee->ctx, entry, offs);
+	return rc;
+}
+
+static int optee_smc_reclaim_protmem(struct optee *optee,
+				     struct tee_shm *protmem)
+{
+	struct optee_shm_arg_entry *entry;
+	struct optee_msg_arg *msg_arg;
+	struct tee_shm *shm;
+	u_int offs;
+	int rc;
+
+	msg_arg = optee_get_msg_arg(optee->ctx, 1, &entry, &shm, &offs);
+	if (IS_ERR(msg_arg))
+		return PTR_ERR(msg_arg);
+
+	msg_arg->cmd = OPTEE_MSG_CMD_RECLAIM_PROTMEM;
+	msg_arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_RMEM_INPUT;
+	msg_arg->params[0].u.rmem.shm_ref = (u_long)protmem;
+
+	rc = optee->ops->do_call_with_arg(optee->ctx, shm, offs, false);
+	if (rc)
+		goto out;
+	if (msg_arg->ret != TEEC_SUCCESS)
+		rc = -EINVAL;
+
+out:
+	optee_free_msg_arg(optee->ctx, entry, offs);
+	return rc;
+}
+
 /*
  * 5. Asynchronous notification
  */
···
 	.do_call_with_arg = optee_smc_do_call_with_arg,
 	.to_msg_param = optee_to_msg_param,
 	.from_msg_param = optee_from_msg_param,
+	.lend_protmem = optee_smc_lend_protmem,
+	.reclaim_protmem = optee_smc_reclaim_protmem,
 };
 
 static int enable_async_notif(optee_invoke_fn *invoke_fn)
···
 }
 #endif
 
+static struct tee_protmem_pool *static_protmem_pool_init(struct optee *optee)
+{
+#if IS_ENABLED(CONFIG_OPTEE_STATIC_PROTMEM_POOL)
+	union {
+		struct arm_smccc_res smccc;
+		struct optee_smc_get_protmem_config_result result;
+	} res;
+	struct tee_protmem_pool *pool;
+	void *p;
+	int rc;
+
+	optee->smc.invoke_fn(OPTEE_SMC_GET_PROTMEM_CONFIG, 0, 0, 0, 0,
+			     0, 0, 0, &res.smccc);
+	if (res.result.status != OPTEE_SMC_RETURN_OK)
+		return ERR_PTR(-EINVAL);
+
+	rc = optee_set_dma_mask(optee, res.result.pa_width);
+	if (rc)
+		return ERR_PTR(rc);
+
+	/*
+	 * Map the memory as uncached to make sure the kernel can work with
+	 * __pfn_to_page() and friends since that's needed when passing the
+	 * protected DMA-buf to a device. The memory should otherwise not
+	 * be touched by the kernel since it's likely to cause an external
+	 * abort due to the protection status.
+	 */
+	p = devm_memremap(&optee->teedev->dev, res.result.start,
+			  res.result.size, MEMREMAP_WC);
+	if (IS_ERR(p))
+		return p;
+
+	pool = tee_protmem_static_pool_alloc(res.result.start, res.result.size);
+	if (IS_ERR(pool))
+		devm_memunmap(&optee->teedev->dev, p);
+
+	return pool;
+#else
+	return ERR_PTR(-EINVAL);
+#endif
+}
+
+static int optee_protmem_pool_init(struct optee *optee)
+{
+	bool protm = optee->smc.sec_caps & OPTEE_SMC_SEC_CAP_PROTMEM;
+	bool dyn_protm = optee->smc.sec_caps &
+			 OPTEE_SMC_SEC_CAP_DYNAMIC_PROTMEM;
+	enum tee_dma_heap_id heap_id = TEE_DMA_HEAP_SECURE_VIDEO_PLAY;
+	struct tee_protmem_pool *pool = ERR_PTR(-EINVAL);
+	int rc = -EINVAL;
+
+	if (!protm && !dyn_protm)
+		return 0;
+
+	if (protm)
+		pool = static_protmem_pool_init(optee);
+	if (dyn_protm && IS_ERR(pool))
+		pool = optee_protmem_alloc_dyn_pool(optee, heap_id);
+	if (IS_ERR(pool))
+		return PTR_ERR(pool);
+
+	rc = tee_device_register_dma_heap(optee->teedev, heap_id, pool);
+	if (rc)
+		pool->ops->destroy_pool(pool);
+
+	return rc;
+}
+
 static int optee_probe(struct platform_device *pdev)
 {
 	optee_invoke_fn *invoke_fn;
···
 	optee = kzalloc(sizeof(*optee), GFP_KERNEL);
 	if (!optee) {
 		rc = -ENOMEM;
-		goto err_free_pool;
+		goto err_free_shm_pool;
 	}
 
 	optee->ops = &optee_ops;
···
 		pr_info("Asynchronous notifications enabled\n");
 	}
 
+	if (optee_protmem_pool_init(optee))
+		pr_info("Protected memory service not available\n");
+
 	/*
 	 * Ensure that there are no pre-existing shm objects before enabling
 	 * the shm cache so that there's no chance of receiving an invalid
···
 	tee_device_unregister(optee->teedev);
 err_free_optee:
 	kfree(optee);
-err_free_pool:
+err_free_shm_pool:
 	tee_shm_pool_free(pool);
 	if (memremaped_shm)
 		memunmap(memremaped_shm);

drivers/tee/tee_core.c

···
 	return ret;
 }
 
+static int
+tee_ioctl_shm_register_fd(struct tee_context *ctx,
+			  struct tee_ioctl_shm_register_fd_data __user *udata)
+{
+	struct tee_ioctl_shm_register_fd_data data;
+	struct tee_shm *shm;
+	long ret;
+
+	if (copy_from_user(&data, udata, sizeof(data)))
+		return -EFAULT;
+
+	/* Currently no input flags are supported */
+	if (data.flags)
+		return -EINVAL;
+
+	shm = tee_shm_register_fd(ctx, data.fd);
+	if (IS_ERR(shm))
+		return -EINVAL;
+
+	data.id = shm->id;
+	data.flags = shm->flags;
+	data.size = shm->size;
+
+	if (copy_to_user(udata, &data, sizeof(data)))
+		ret = -EFAULT;
+	else
+		ret = tee_shm_get_fd(shm);
+
+	/*
+	 * When user space closes the file descriptor the shared memory
+	 * should be freed or if tee_shm_get_fd() failed then it will
+	 * be freed immediately.
+	 */
+	tee_shm_put(shm);
+	return ret;
+}
+
+static int param_from_user_memref(struct tee_context *ctx,
+				  struct tee_param_memref *memref,
+				  struct tee_ioctl_param *ip)
+{
+	struct tee_shm *shm;
+	size_t offs = 0;
+
+	/*
+	 * If a NULL pointer is passed to a TA in the TEE,
+	 * the ip.c IOCTL parameters is set to TEE_MEMREF_NULL
+	 * indicating a NULL memory reference.
+	 */
+	if (ip->c != TEE_MEMREF_NULL) {
+		/*
+		 * If we fail to get a pointer to a shared
+		 * memory object (and increase the ref count)
+		 * from an identifier we return an error. All
+		 * pointers that has been added in params have
+		 * an increased ref count. It's the callers
+		 * responibility to do tee_shm_put() on all
+		 * resolved pointers.
+		 */
+		shm = tee_shm_get_from_id(ctx, ip->c);
+		if (IS_ERR(shm))
+			return PTR_ERR(shm);
+
+		/*
+		 * Ensure offset + size does not overflow
+		 * offset and does not overflow the size of
+		 * the referred shared memory object.
+		 */
+		if ((ip->a + ip->b) < ip->a ||
+		    (ip->a + ip->b) > shm->size) {
+			tee_shm_put(shm);
+			return -EINVAL;
+		}
+
+		if (shm->flags & TEE_SHM_DMA_BUF) {
+			struct tee_shm_dmabuf_ref *ref;
+
+			ref = container_of(shm, struct tee_shm_dmabuf_ref, shm);
+			if (ref->parent_shm) {
+				/*
+				 * The shm already has one reference to
+				 * ref->parent_shm so we are clear of 0.
+				 * We're getting another reference since
+				 * this shm will be used in the parameter
+				 * list instead of the shm we got with
+				 * tee_shm_get_from_id() above.
+				 */
+				refcount_inc(&ref->parent_shm->refcount);
+				tee_shm_put(shm);
+				shm = ref->parent_shm;
+				offs = ref->offset;
+			}
+		}
+	} else if (ctx->cap_memref_null) {
+		/* Pass NULL pointer to OP-TEE */
+		shm = NULL;
+	} else {
+		return -EINVAL;
+	}
+
+	memref->shm_offs = ip->a + offs;
+	memref->size = ip->b;
+	memref->shm = shm;
+
+	return 0;
+}
+
 static int params_from_user(struct tee_context *ctx, struct tee_param *params,
 			    size_t num_params,
 			    struct tee_ioctl_param __user *uparams)
···
 	size_t n;
 
 	for (n = 0; n < num_params; n++) {
-		struct tee_shm *shm;
 		struct tee_ioctl_param ip;
+		int rc;
 
 		if (copy_from_user(&ip, uparams + n, sizeof(ip)))
 			return -EFAULT;
···
 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT:
 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
 		case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
-			/*
-			 * If a NULL pointer is passed to a TA in the TEE,
-			 * the ip.c IOCTL parameters is set to TEE_MEMREF_NULL
-			 * indicating a NULL memory reference.
-			 */
-			if (ip.c != TEE_MEMREF_NULL) {
-				/*
-				 * If we fail to get a pointer to a shared
-				 * memory object (and increase the ref count)
-				 * from an identifier we return an error. All
-				 * pointers that has been added in params have
-				 * an increased ref count. It's the callers
-				 * responibility to do tee_shm_put() on all
-				 * resolved pointers.
-				 */
-				shm = tee_shm_get_from_id(ctx, ip.c);
-				if (IS_ERR(shm))
-					return PTR_ERR(shm);
-
-				/*
-				 * Ensure offset + size does not overflow
-				 * offset and does not overflow the size of
-				 * the referred shared memory object.
-				 */
-				if ((ip.a + ip.b) < ip.a ||
-				    (ip.a + ip.b) > shm->size) {
-					tee_shm_put(shm);
-					return -EINVAL;
-				}
-			} else if (ctx->cap_memref_null) {
-				/* Pass NULL pointer to OP-TEE */
-				shm = NULL;
-			} else {
-				return -EINVAL;
-			}
-
-			params[n].u.memref.shm_offs = ip.a;
-			params[n].u.memref.size = ip.b;
-			params[n].u.memref.shm = shm;
+			rc = param_from_user_memref(ctx, &params[n].u.memref,
+						    &ip);
+			if (rc)
+				return rc;
 			break;
 		default:
 			/* Unknown attribute */
···
 		return tee_ioctl_shm_alloc(ctx, uarg);
 	case TEE_IOC_SHM_REGISTER:
 		return tee_ioctl_shm_register(ctx, uarg);
+	case TEE_IOC_SHM_REGISTER_FD:
+		return tee_ioctl_shm_register_fd(ctx, uarg);
 	case TEE_IOC_OPEN_SESSION:
 		return tee_ioctl_open_session(ctx, uarg);
 	case TEE_IOC_INVOKE:
···
 	if (!teedev)
 		return;
 
+	tee_device_put_all_dma_heaps(teedev);
+
 	if (teedev->flags & TEE_DEVICE_FLAG_REGISTERED)
 		cdev_device_del(&teedev->cdev, &teedev->dev);
 
···
 MODULE_DESCRIPTION("TEE Driver");
 MODULE_VERSION("1.0");
 MODULE_LICENSE("GPL v2");
+MODULE_IMPORT_NS("DMA_BUF");
+MODULE_IMPORT_NS("DMA_BUF_HEAP");

drivers/tee/tee_heap.c

···
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2025, Linaro Limited
+ */
+
+#include <linux/dma-buf.h>
+#include <linux/dma-heap.h>
+#include <linux/genalloc.h>
+#include <linux/module.h>
+#include <linux/scatterlist.h>
+#include <linux/slab.h>
+#include <linux/tee_core.h>
+#include <linux/xarray.h>
+
+#include "tee_private.h"
+
+struct tee_dma_heap {
+	struct dma_heap *heap;
+	enum tee_dma_heap_id id;
+	struct kref kref;
+	struct tee_protmem_pool *pool;
+	struct tee_device *teedev;
+	bool shutting_down;
+	/* Protects pool, teedev, and shutting_down above */
+	struct mutex mu;
+};
+
+struct tee_heap_buffer {
+	struct tee_dma_heap *heap;
+	size_t size;
+	size_t offs;
+	struct sg_table table;
+};
+
+struct tee_heap_attachment {
+	struct sg_table table;
+	struct device *dev;
+};
+
+struct tee_protmem_static_pool {
+	struct tee_protmem_pool pool;
+	struct gen_pool *gen_pool;
+	phys_addr_t pa_base;
+};
+
+#if IS_ENABLED(CONFIG_TEE_DMABUF_HEAPS)
+static DEFINE_XARRAY_ALLOC(tee_dma_heap);
+
+static void tee_heap_release(struct kref *kref)
+{
+	struct tee_dma_heap *h = container_of(kref, struct tee_dma_heap, kref);
+
+	h->pool->ops->destroy_pool(h->pool);
+	tee_device_put(h->teedev);
+	h->pool = NULL;
+	h->teedev = NULL;
+}
+
+static void put_tee_heap(struct tee_dma_heap *h)
+{
+	kref_put(&h->kref, tee_heap_release);
+}
+
+static void get_tee_heap(struct tee_dma_heap *h)
+{
+	kref_get(&h->kref);
+}
+
+static int copy_sg_table(struct sg_table *dst, struct sg_table *src)
+{
+	struct scatterlist *dst_sg;
+	struct scatterlist *src_sg;
+	int ret;
+	int i;
+
+	ret = sg_alloc_table(dst, src->orig_nents, GFP_KERNEL);
+	if (ret)
+		return ret;
+
+	dst_sg = dst->sgl;
+	for_each_sgtable_sg(src, src_sg, i) {
+		sg_set_page(dst_sg, sg_page(src_sg), src_sg->length,
+			    src_sg->offset);
+		dst_sg = sg_next(dst_sg);
+	}
+
+	return 0;
+}
+
+static int tee_heap_attach(struct dma_buf *dmabuf,
+			   struct dma_buf_attachment *attachment)
+{
+	struct tee_heap_buffer *buf = dmabuf->priv;
+	struct tee_heap_attachment *a;
+	int ret;
+
+	a = kzalloc(sizeof(*a), GFP_KERNEL);
+	if (!a)
+		return -ENOMEM;
+
+	ret = copy_sg_table(&a->table, &buf->table);
+	if (ret) {
+		kfree(a);
+		return ret;
+	}
+
+	a->dev = attachment->dev;
+	attachment->priv = a;
+
+	return 0;
+}
+
+static void tee_heap_detach(struct dma_buf *dmabuf,
+			    struct dma_buf_attachment *attachment)
+{
+	struct tee_heap_attachment *a = attachment->priv;
+
+	sg_free_table(&a->table);
+	kfree(a);
+}
+
+static struct sg_table *
+tee_heap_map_dma_buf(struct dma_buf_attachment *attachment,
+		     enum dma_data_direction direction)
+{
+	struct tee_heap_attachment *a = attachment->priv;
+	int ret;
+
+	ret = dma_map_sgtable(attachment->dev, &a->table, direction,
+			      DMA_ATTR_SKIP_CPU_SYNC);
+	if (ret)
+		return ERR_PTR(ret);
+
+	return &a->table;
+}
+
+static void tee_heap_unmap_dma_buf(struct dma_buf_attachment *attachment,
+				   struct sg_table *table,
+				   enum dma_data_direction direction)
+{
+	struct tee_heap_attachment *a = attachment->priv;
+
+	WARN_ON(&a->table != table);
+
+	dma_unmap_sgtable(attachment->dev, table, direction,
+			  DMA_ATTR_SKIP_CPU_SYNC);
+}
+
+static void tee_heap_buf_free(struct dma_buf *dmabuf)
+{
+	struct tee_heap_buffer *buf = dmabuf->priv;
+
+	buf->heap->pool->ops->free(buf->heap->pool, &buf->table);
+	mutex_lock(&buf->heap->mu);
+	put_tee_heap(buf->heap);
+	mutex_unlock(&buf->heap->mu);
+	kfree(buf);
+}
+
+static const struct dma_buf_ops tee_heap_buf_ops = {
+	.attach = tee_heap_attach,
+	.detach = tee_heap_detach,
+	.map_dma_buf = tee_heap_map_dma_buf,
+	.unmap_dma_buf = tee_heap_unmap_dma_buf,
+	.release = tee_heap_buf_free,
+};
+
+static struct dma_buf *tee_dma_heap_alloc(struct dma_heap *heap,
+					  unsigned long len, u32 fd_flags,
+					  u64 heap_flags)
+{
+	struct tee_dma_heap *h = dma_heap_get_drvdata(heap);
+	DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
+	struct tee_device *teedev = NULL;
+	struct tee_heap_buffer *buf;
+	struct tee_protmem_pool *pool;
+	struct dma_buf *dmabuf;
+	int rc;
+
+	mutex_lock(&h->mu);
+	if (h->teedev) {
+		teedev = h->teedev;
+		pool = h->pool;
+		get_tee_heap(h);
+	}
+	mutex_unlock(&h->mu);
+
+	if (!teedev)
+		return ERR_PTR(-EINVAL);
+
+	buf = kzalloc(sizeof(*buf), GFP_KERNEL);
+	if (!buf) {
+		dmabuf = ERR_PTR(-ENOMEM);
+		goto err;
+	}
+	buf->size = len;
+	buf->heap = h;
+
+	rc = pool->ops->alloc(pool, &buf->table, len, &buf->offs);
+	if (rc) {
+		dmabuf = ERR_PTR(rc);
+		goto err_kfree;
+	}
+
+	exp_info.ops = &tee_heap_buf_ops;
+	exp_info.size = len;
+	exp_info.priv = buf;
+	exp_info.flags = fd_flags;
+	dmabuf = dma_buf_export(&exp_info);
+	if (IS_ERR(dmabuf))
+		goto err_protmem_free;
+
+	return dmabuf;
+
+err_protmem_free:
+	pool->ops->free(pool, &buf->table);
+err_kfree:
+	kfree(buf);
+err:
+	mutex_lock(&h->mu);
+	put_tee_heap(h);
+	mutex_unlock(&h->mu);
+	return dmabuf;
+}
+
+static const struct dma_heap_ops tee_dma_heap_ops = {
+	.allocate = tee_dma_heap_alloc,
+};
+
+static const char *heap_id_2_name(enum tee_dma_heap_id id)
+{
+	switch (id) {
+	case TEE_DMA_HEAP_SECURE_VIDEO_PLAY:
+		return "protected,secure-video";
+	case TEE_DMA_HEAP_TRUSTED_UI:
+		return "protected,trusted-ui";
+	case TEE_DMA_HEAP_SECURE_VIDEO_RECORD:
+		return "protected,secure-video-record";
+	default:
+		return NULL;
+	}
+}
+
+static int alloc_dma_heap(struct tee_device *teedev, enum tee_dma_heap_id id,
+			  struct tee_protmem_pool *pool)
+{
+	struct dma_heap_export_info exp_info = {
+		.ops = &tee_dma_heap_ops,
+		.name = heap_id_2_name(id),
+	};
+	struct tee_dma_heap *h;
+	int rc;
+
+	if (!exp_info.name)
+		return -EINVAL;
+
+	if (xa_reserve(&tee_dma_heap, id, GFP_KERNEL)) {
+		if (!xa_load(&tee_dma_heap, id))
+			return -EEXIST;
+		return -ENOMEM;
+	}
+
+	h = kzalloc(sizeof(*h), GFP_KERNEL);
+	if (!h)
+		return -ENOMEM;
+	h->id = id;
+	kref_init(&h->kref);
+	h->teedev = teedev;
+	h->pool = pool;
+	mutex_init(&h->mu);
+
+	exp_info.priv = h;
+	h->heap = dma_heap_add(&exp_info);
+	if (IS_ERR(h->heap)) {
+		rc = PTR_ERR(h->heap);
+		kfree(h);
+
+		return rc;
+	}
+
+	/* "can't fail" due to the call to xa_reserve() above */
+	return WARN_ON(xa_is_err(xa_store(&tee_dma_heap, id, h, GFP_KERNEL)));
+}
+
+int tee_device_register_dma_heap(struct tee_device *teedev,
+				 enum tee_dma_heap_id id,
+				 struct tee_protmem_pool *pool)
+{
+	struct tee_dma_heap *h;
+	int rc;
+
+	if (!tee_device_get(teedev))
+		return -EINVAL;
+
+	h = xa_load(&tee_dma_heap, id);
+	if (h) {
+		mutex_lock(&h->mu);
+		if (h->teedev) {
+			rc = -EBUSY;
+		} else {
+			kref_init(&h->kref);
+			h->shutting_down = false;
+			h->teedev = teedev;
+			h->pool = pool;
+			rc = 0;
+		}
+		mutex_unlock(&h->mu);
+	} else {
+		rc = alloc_dma_heap(teedev, id, pool);
+	}
+
+	if (rc) {
+		tee_device_put(teedev);
+		dev_err(&teedev->dev, "can't register DMA heap id %d (%s)\n",
+			id, heap_id_2_name(id));
+	}
+
+	return rc;
+}
+EXPORT_SYMBOL_GPL(tee_device_register_dma_heap);
+
+void tee_device_put_all_dma_heaps(struct tee_device *teedev)
+{
+	struct tee_dma_heap *h;
+	u_long i;
+
+	xa_for_each(&tee_dma_heap, i, h) {
+		if (h) {
+			mutex_lock(&h->mu);
+			if (h->teedev == teedev && !h->shutting_down) {
+				h->shutting_down = true;
+				put_tee_heap(h);
+			}
+			mutex_unlock(&h->mu);
+		}
+	}
+}
+EXPORT_SYMBOL_GPL(tee_device_put_all_dma_heaps);
+
+int tee_heap_update_from_dma_buf(struct tee_device *teedev,
+				 struct dma_buf *dmabuf, size_t *offset,
+				 struct tee_shm *shm,
+				 struct tee_shm **parent_shm)
+{
+	struct tee_heap_buffer *buf;
+	int rc;
+
+	/* The DMA-buf must be from our heap */
+	if (dmabuf->ops != &tee_heap_buf_ops)
+		return -EINVAL;
+
+	buf = dmabuf->priv;
+	/* The buffer must be from the same teedev */
+	if (buf->heap->teedev != teedev)
+		return -EINVAL;
+
+	shm->size = buf->size;
+
+	rc = buf->heap->pool->ops->update_shm(buf->heap->pool, &buf->table,
+					      buf->offs, shm, parent_shm);
+	if (!rc && *parent_shm)
+		*offset = buf->offs;
+
+	return rc;
+}
+#else
+int tee_device_register_dma_heap(struct tee_device *teedev __always_unused,
+				 enum tee_dma_heap_id id __always_unused,
+				 struct tee_protmem_pool *pool __always_unused)
+{
+	return -EINVAL;
+}
+EXPORT_SYMBOL_GPL(tee_device_register_dma_heap);
+
+void
+tee_device_put_all_dma_heaps(struct tee_device *teedev __always_unused)
+{
+}
+EXPORT_SYMBOL_GPL(tee_device_put_all_dma_heaps);
+
+int tee_heap_update_from_dma_buf(struct tee_device *teedev __always_unused,
+				 struct dma_buf *dmabuf __always_unused,
+				 size_t *offset __always_unused,
+				 struct tee_shm *shm __always_unused,
+				 struct tee_shm **parent_shm __always_unused)
+{
+	return -EINVAL;
+}
+#endif
+
+static struct tee_protmem_static_pool *
+to_protmem_static_pool(struct tee_protmem_pool *pool)
+{
+	return container_of(pool, struct tee_protmem_static_pool, pool);
+}
+
+static int protmem_pool_op_static_alloc(struct tee_protmem_pool *pool,
+					struct sg_table *sgt, size_t size,
+					size_t *offs)
+{
+	struct tee_protmem_static_pool *stp = to_protmem_static_pool(pool);
+	phys_addr_t pa;
+	int ret;
+
+	pa = gen_pool_alloc(stp->gen_pool, size);
+	if (!pa)
+		return -ENOMEM;
+
+	ret = sg_alloc_table(sgt, 1, GFP_KERNEL);
+	if (ret) {
+		gen_pool_free(stp->gen_pool, pa, size);
+		return ret;
+	}
+
+	sg_set_page(sgt->sgl, phys_to_page(pa), size, 0);
+	*offs = pa - stp->pa_base;
+
+	return 0;
+}
+
+static void protmem_pool_op_static_free(struct tee_protmem_pool *pool,
+					struct sg_table *sgt)
+{
+	struct tee_protmem_static_pool *stp = to_protmem_static_pool(pool);
+	struct scatterlist *sg;
+	int i;
+
+	for_each_sgtable_sg(sgt, sg, i)
+		gen_pool_free(stp->gen_pool, sg_phys(sg), sg->length);
+	sg_free_table(sgt);
+}
+
+static int protmem_pool_op_static_update_shm(struct tee_protmem_pool *pool,
+					     struct sg_table *sgt, size_t offs,
+					     struct tee_shm *shm,
+					     struct tee_shm **parent_shm)
+{
+	struct tee_protmem_static_pool *stp = to_protmem_static_pool(pool);
+
+	shm->paddr = stp->pa_base + offs;
+	*parent_shm = NULL;
+
+	return 0;
+}
+
+static void protmem_pool_op_static_destroy_pool(struct tee_protmem_pool *pool)
+{
+	struct tee_protmem_static_pool *stp = to_protmem_static_pool(pool);
+
+	gen_pool_destroy(stp->gen_pool);
+	kfree(stp);
+}
+
+static struct tee_protmem_pool_ops protmem_pool_ops_static = {
+	.alloc = protmem_pool_op_static_alloc,
+	.free = protmem_pool_op_static_free,
+	.update_shm = protmem_pool_op_static_update_shm,
+	.destroy_pool = protmem_pool_op_static_destroy_pool,
+};
+
+struct tee_protmem_pool *tee_protmem_static_pool_alloc(phys_addr_t paddr,
+						       size_t size)
+{
+	const size_t page_mask = PAGE_SIZE - 1;
+	struct tee_protmem_static_pool *stp;
+	int rc;
+
+	/* Check it's page aligned */
+	if ((paddr | size) & page_mask)
+		return ERR_PTR(-EINVAL);
+
+	if (!pfn_valid(PHYS_PFN(paddr)))
+		return ERR_PTR(-EINVAL);
+
+	stp = kzalloc(sizeof(*stp), GFP_KERNEL);
+	if (!stp)
+		return ERR_PTR(-ENOMEM);
+
+	stp->gen_pool = gen_pool_create(PAGE_SHIFT, -1);
+	if (!stp->gen_pool) {
+		rc = -ENOMEM;
+		goto err_free;
+	}
+
+	rc = gen_pool_add(stp->gen_pool, paddr, size, -1);
+	if (rc)
+		goto err_free_pool;
+
+	stp->pool.ops = &protmem_pool_ops_static;
+	stp->pa_base = paddr;
+	return &stp->pool;
+
+err_free_pool:
+	gen_pool_destroy(stp->gen_pool);
+err_free:
+	kfree(stp);
+
+	return ERR_PTR(rc);
+}
+EXPORT_SYMBOL_GPL(tee_protmem_static_pool_alloc);

drivers/tee/tee_private.h

···
 #include <linux/cdev.h>
 #include <linux/completion.h>
 #include <linux/device.h>
+#include <linux/dma-buf.h>
 #include <linux/kref.h>
 #include <linux/mutex.h>
 #include <linux/types.h>
+
+/* extra references appended to shm object for registered shared memory */
+struct tee_shm_dmabuf_ref {
+	struct tee_shm shm;
+	size_t offset;
+	struct dma_buf *dmabuf;
+	struct tee_shm *parent_shm;
+};
 
 int tee_shm_get_fd(struct tee_shm *shm);
 
···
 struct tee_shm *tee_shm_alloc_user_buf(struct tee_context *ctx, size_t size);
 struct tee_shm *tee_shm_register_user_buf(struct tee_context *ctx,
 					  unsigned long addr, size_t length);
+
+int tee_heap_update_from_dma_buf(struct tee_device *teedev,
+				 struct dma_buf *dmabuf, size_t *offset,
+				 struct tee_shm *shm,
+				 struct tee_shm **parent_shm);
 
 #endif /*TEE_PRIVATE_H*/

drivers/tee/tee_shm.c

···
  */
 #include <linux/anon_inodes.h>
 #include <linux/device.h>
+#include <linux/dma-buf.h>
+#include <linux/dma-mapping.h>
+#include <linux/highmem.h>
 #include <linux/idr.h>
 #include <linux/io.h>
 #include <linux/mm.h>
···
 #include <linux/tee_core.h>
 #include <linux/uaccess.h>
 #include <linux/uio.h>
-#include <linux/highmem.h>
 #include "tee_private.h"
+
+struct tee_shm_dma_mem {
+	struct tee_shm shm;
+	dma_addr_t dma_addr;
+	struct page *page;
+};
 
 static void shm_put_kernel_pages(struct page **pages, size_t page_count)
 {
···
 
 static void tee_shm_release(struct tee_device *teedev, struct tee_shm *shm)
 {
-	if (shm->flags & TEE_SHM_POOL) {
+	void *p = shm;
+
+	if (shm->flags & TEE_SHM_DMA_MEM) {
+#if IS_ENABLED(CONFIG_TEE_DMABUF_HEAPS)
+		struct tee_shm_dma_mem *dma_mem;
+
+		dma_mem = container_of(shm, struct tee_shm_dma_mem, shm);
+		p = dma_mem;
+		dma_free_pages(&teedev->dev, shm->size, dma_mem->page,
+			       dma_mem->dma_addr, DMA_BIDIRECTIONAL);
+#endif
+	} else if (shm->flags & TEE_SHM_DMA_BUF) {
+		struct tee_shm_dmabuf_ref *ref;
+
+		ref = container_of(shm, struct tee_shm_dmabuf_ref, shm);
+		p = ref;
+		dma_buf_put(ref->dmabuf);
+	} else if (shm->flags & TEE_SHM_POOL) {
 		teedev->pool->ops->free(teedev->pool, shm);
 	} else if (shm->flags & TEE_SHM_DYNAMIC) {
 		int rc = teedev->desc->ops->shm_unregister(shm->ctx, shm);
···
 
 	teedev_ctx_put(shm->ctx);
 
-	kfree(shm);
+	kfree(p);
 
 	tee_device_put(teedev);
 }
···
  * tee_client_invoke_func(). The memory allocated is later freed with a
  * call to tee_shm_free().
  *
- * @returns a pointer to 'struct tee_shm'
+ * @returns a pointer to 'struct tee_shm' on success, and ERR_PTR on failure
  */
 struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, size_t size)
 {
···
 	return shm_alloc_helper(ctx, size, PAGE_SIZE, flags, -1);
 }
 EXPORT_SYMBOL_GPL(tee_shm_alloc_kernel_buf);
+
+struct tee_shm *tee_shm_register_fd(struct tee_context *ctx, int fd)
+{
+	struct tee_shm_dmabuf_ref *ref;
+	int rc;
+
+	if (!tee_device_get(ctx->teedev))
+		return ERR_PTR(-EINVAL);
+
+	teedev_ctx_get(ctx);
+
+	ref = kzalloc(sizeof(*ref), GFP_KERNEL);
+	if (!ref) {
+		rc = -ENOMEM;
+		goto err_put_tee;
+	}
+
+	refcount_set(&ref->shm.refcount, 1);
+	ref->shm.ctx = ctx;
+	ref->shm.id = -1;
+	ref->shm.flags = TEE_SHM_DMA_BUF;
+
+	ref->dmabuf = dma_buf_get(fd);
+	if (IS_ERR(ref->dmabuf)) {
+		rc = PTR_ERR(ref->dmabuf);
+		goto err_kfree_ref;
+	}
+
+	rc = tee_heap_update_from_dma_buf(ctx->teedev, ref->dmabuf,
+					  &ref->offset, &ref->shm,
+					  &ref->parent_shm);
+	if (rc)
+		goto err_put_dmabuf;
+
+	mutex_lock(&ref->shm.ctx->teedev->mutex);
+	ref->shm.id = idr_alloc(&ref->shm.ctx->teedev->idr, &ref->shm,
+				1, 0, GFP_KERNEL);
+	mutex_unlock(&ref->shm.ctx->teedev->mutex);
+	if (ref->shm.id < 0) {
+		rc = ref->shm.id;
+		goto err_put_dmabuf;
+	}
+
+	return &ref->shm;
+
+err_put_dmabuf:
+	dma_buf_put(ref->dmabuf);
+err_kfree_ref:
+	kfree(ref);
+err_put_tee:
+	teedev_ctx_put(ctx);
+	tee_device_put(ctx->teedev);
+
+	return ERR_PTR(rc);
+}
+EXPORT_SYMBOL_GPL(tee_shm_register_fd);
 
 /**
  * tee_shm_alloc_priv_buf() - Allocate shared memory for a privately shared
···
 	return shm_alloc_helper(ctx, size, sizeof(long) * 2, flags, -1);
 }
 EXPORT_SYMBOL_GPL(tee_shm_alloc_priv_buf);
+
+#if IS_ENABLED(CONFIG_TEE_DMABUF_HEAPS)
+/**
+ * tee_shm_alloc_dma_mem() - Allocate DMA memory as shared memory object
+ * @ctx:	Context that allocates the shared memory
+ * @page_count:	Number of pages
+ *
+ * The allocated memory is expected to be lent (made inaccessible to the
+ * kernel) to the TEE while it's used and returned (accessible to the
+ * kernel again) before it's freed.
+ *
+ * This function should normally only be used internally in the TEE
+ * drivers.
+ *
+ * @returns a pointer to 'struct tee_shm'
+ */
+struct tee_shm *tee_shm_alloc_dma_mem(struct tee_context *ctx,
+				      size_t page_count)
+{
+	struct tee_device *teedev = ctx->teedev;
+	struct tee_shm_dma_mem *dma_mem;
+	dma_addr_t dma_addr;
+	struct page *page;
+
+	if (!tee_device_get(teedev))
+		return ERR_PTR(-EINVAL);
+
+	page = dma_alloc_pages(&teedev->dev, page_count * PAGE_SIZE,
+			       &dma_addr, DMA_BIDIRECTIONAL, GFP_KERNEL);
+	if (!page)
+		goto err_put_teedev;
+
+	dma_mem = kzalloc(sizeof(*dma_mem), GFP_KERNEL);
+	if (!dma_mem)
+		goto err_free_pages;
+
+	refcount_set(&dma_mem->shm.refcount, 1);
+	dma_mem->shm.ctx = ctx;
+	dma_mem->shm.paddr = page_to_phys(page);
+	dma_mem->dma_addr = dma_addr;
+	dma_mem->page = page;
+	dma_mem->shm.size = page_count * PAGE_SIZE;
+	dma_mem->shm.flags = TEE_SHM_DMA_MEM;
+
+	teedev_ctx_get(ctx);
+
+	return &dma_mem->shm;
+
+err_free_pages:
+	dma_free_pages(&teedev->dev, page_count * PAGE_SIZE, page, dma_addr,
+		       DMA_BIDIRECTIONAL);
+err_put_teedev:
+	tee_device_put(teedev);
+
+	return ERR_PTR(-ENOMEM);
+}
+EXPORT_SYMBOL_GPL(tee_shm_alloc_dma_mem);
+#else
+struct tee_shm *tee_shm_alloc_dma_mem(struct tee_context *ctx,
+				      size_t page_count)
+{
+	return ERR_PTR(-EINVAL);
+}
+EXPORT_SYMBOL_GPL(tee_shm_alloc_dma_mem);
+#endif
 
 int tee_dyn_shm_alloc_helper(struct tee_shm *shm, size_t size, size_t align,
 			     int (*shm_register)(struct tee_context *ctx,
···
 
 	/* Refuse sharing shared memory provided by application */
 	if (shm->flags & TEE_SHM_USER_MAPPED)
+		return -EINVAL;
+	/* Refuse sharing registered DMA_bufs with the application */
+	if (shm->flags & TEE_SHM_DMA_BUF)
 		return -EINVAL;
 
 	/* check for overflowing the buffer's size */

include/linux/tee_core.h

···
 
 #include <linux/cdev.h>
 #include <linux/device.h>
+#include <linux/dma-buf.h>
 #include <linux/idr.h>
 #include <linux/kref.h>
 #include <linux/list.h>
+#include <linux/scatterlist.h>
 #include <linux/tee.h>
 #include <linux/tee_drv.h>
 #include <linux/types.h>
···
 #define TEE_SHM_USER_MAPPED	BIT(1)  /* Memory mapped in user space */
 #define TEE_SHM_POOL		BIT(2)  /* Memory allocated from pool */
 #define TEE_SHM_PRIV		BIT(3)  /* Memory private to TEE driver */
+#define TEE_SHM_DMA_BUF		BIT(4)	/* Memory with dma-buf handle */
+#define TEE_SHM_DMA_MEM		BIT(5)	/* Memory allocated with */
+					/* dma_alloc_pages() */
 
 #define TEE_DEVICE_FLAG_REGISTERED	0x1
 #define TEE_MAX_DEV_NAME_LEN		32
+
+enum tee_dma_heap_id {
+	TEE_DMA_HEAP_SECURE_VIDEO_PLAY = 1,
+	TEE_DMA_HEAP_TRUSTED_UI,
+	TEE_DMA_HEAP_SECURE_VIDEO_RECORD,
+};
 
 /**
  * struct tee_device - TEE Device representation
···
 };
 
 /**
+ * struct tee_protmem_pool - protected memory pool
+ * @ops:		operations
+ *
+ * This is an abstract interface where this struct is expected to be
+ * embedded in another struct specific to the implementation.
+ */
+struct tee_protmem_pool {
+	const struct tee_protmem_pool_ops *ops;
+};
+
+/**
+ * struct tee_protmem_pool_ops - protected memory pool operations
+ * @alloc:		called when allocating protected memory
+ * @free:		called when freeing protected memory
+ * @update_shm:		called when registering a dma-buf to update the @shm
+ *			with physical address of the buffer or to return the
+ *			@parent_shm of the memory pool
+ * @destroy_pool:	called when destroying the pool
+ */
+struct tee_protmem_pool_ops {
+	int (*alloc)(struct tee_protmem_pool *pool, struct sg_table *sgt,
+		     size_t size, size_t *offs);
+	void (*free)(struct tee_protmem_pool *pool, struct sg_table *sgt);
+	int (*update_shm)(struct tee_protmem_pool *pool, struct sg_table *sgt,
+			  size_t offs, struct tee_shm *shm,
+			  struct tee_shm **parent_shm);
+	void (*destroy_pool)(struct tee_protmem_pool *pool);
+};
+
+/**
  * tee_device_alloc() - Allocate a new struct tee_device instance
  * @teedesc:	Descriptor for this driver
  * @dev:	Parent device for this device
···
  * @teedev is NULL.
  */
 void tee_device_unregister(struct tee_device *teedev);
+
+int tee_device_register_dma_heap(struct tee_device *teedev,
+				 enum tee_dma_heap_id id,
+				 struct tee_protmem_pool *pool);
+void tee_device_put_all_dma_heaps(struct tee_device *teedev);
 
 /**
  * tee_device_set_dev_groups() - Set device attribute groups
···
 }
 
 /**
+ * tee_protmem_static_pool_alloc() - Create a protected memory manager
+ * @paddr:	Physical address of start of pool
+ * @size:	Size in bytes of the pool
+ *
+ * @returns pointer to a 'struct tee_protmem_pool' or an ERR_PTR on failure.
+ */
+struct tee_protmem_pool *tee_protmem_static_pool_alloc(phys_addr_t paddr,
+						       size_t size);
+
+/**
  * tee_get_drvdata() - Return driver_data pointer
  * @returns the driver_data pointer supplied to tee_register().
  */
···
  * @returns a pointer to 'struct tee_shm' on success or an ERR_PTR on failure
  */
 struct tee_shm *tee_shm_alloc_priv_buf(struct tee_context *ctx, size_t size);
+
+struct tee_shm *tee_shm_alloc_dma_mem(struct tee_context *ctx,
+				      size_t page_count);
 
 int tee_dyn_shm_alloc_helper(struct tee_shm *shm, size_t size, size_t align,
 			     int (*shm_register)(struct tee_context *ctx,

include/linux/tee_drv.h

···
 					    void *addr, size_t length);
 
 /**
+ * tee_shm_register_fd() - Register shared memory from file descriptor
+ *
+ * @ctx:	Context that allocates the shared memory
+ * @fd:		Shared memory file descriptor reference
+ *
+ * @returns a pointer to 'struct tee_shm' on success, and ERR_PTR on failure
+ */
+struct tee_shm *tee_shm_register_fd(struct tee_context *ctx, int fd);
+
+/**
  * tee_shm_free() - Free shared memory
  * @shm:	Handle to shared memory to free
  */

include/uapi/linux/tee.h

···
 };
 
 /**
+ * struct tee_ioctl_shm_register_fd_data - Shared memory registering argument
+ * @fd:		[in] File descriptor identifying dmabuf reference
+ * @size:	[out] Size of referenced memory
+ * @flags:	[in] Flags to/from allocation.
+ * @id:		[out] Identifier of the shared memory
+ *
+ * The flags field should currently be zero as input. Updated by the call
+ * with actual flags as defined by TEE_IOCTL_SHM_* above.
+ * This structure is used as argument for TEE_IOC_SHM_REGISTER_FD below.
+ */
+struct tee_ioctl_shm_register_fd_data {
+	__s64 fd;
+	__u64 size;
+	__u32 flags;
+	__s32 id;
+};
+
+/**
+ * TEE_IOC_SHM_REGISTER_FD - register a shared memory from a file descriptor
+ *
+ * Returns a file descriptor on success or < 0 on failure
+ *
+ * The returned file descriptor refers to the shared memory object in the
+ * kernel. The supplied file deccriptor can be closed if it's not needed
+ * for other purposes. The shared memory is freed when the descriptor is
+ * closed.
+ */
+#define TEE_IOC_SHM_REGISTER_FD	_IOWR(TEE_IOC_MAGIC, TEE_IOC_BASE + 8, \
+				     struct tee_ioctl_shm_register_fd_data)
+
+/**
  * TEE_IOC_SHM_REGISTER - Register shared memory argument
  *
  * Registers shared memory between the user space process and secure OS.