Adding upstream version 6.1.76.upstream/6.1.76

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1591 insertions, 0 deletions

diff --git a/drivers/tee/optee/smc_abi.c b/drivers/tee/optee/smc_abi.c
new file mode 100644
index 000000000..e6e0428f8
--- /dev/null
+++ b/drivers/tee/optee/smc_abi.c
@@ -0,0 +1,1591 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2015-2021, Linaro Limited
+ * Copyright (c) 2016, EPAM Systems
+ */
+
+#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
+
+#include <linux/arm-smccc.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/io.h>
+#include <linux/irqdomain.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_irq.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/sched.h>
+#include <linux/slab.h>
+#include <linux/string.h>
+#include <linux/tee_drv.h>
+#include <linux/types.h>
+#include <linux/workqueue.h>
+#include "optee_private.h"
+#include "optee_smc.h"
+#include "optee_rpc_cmd.h"
+#include <linux/kmemleak.h>
+#define CREATE_TRACE_POINTS
+#include "optee_trace.h"
+
+/*
+ * This file implement the SMC ABI used when communicating with secure world
+ * OP-TEE OS via raw SMCs.
+ * This file is divided into the following sections:
+ * 1. Convert between struct tee_param and struct optee_msg_param
+ * 2. Low level support functions to register shared memory in secure world
+ * 3. Dynamic shared memory pool based on alloc_pages()
+ * 4. Do a normal scheduled call into secure world
+ * 5. Asynchronous notification
+ * 6. Driver initialization.
+ */
+
+/*
+ * A typical OP-TEE private shm allocation is 224 bytes (argument struct
+ * with 6 parameters, needed for open session). So with an alignment of 512
+ * we'll waste a bit more than 50%. However, it's only expected that we'll
+ * have a handful of these structs allocated at a time. Most memory will
+ * be allocated aligned to the page size, So all in all this should scale
+ * up and down quite well.
+ */
+#define OPTEE_MIN_STATIC_POOL_ALIGN    9 /* 512 bytes aligned */
+
+/*
+ * 1. Convert between struct tee_param and struct optee_msg_param
+ *
+ * optee_from_msg_param() and optee_to_msg_param() are the main
+ * functions.
+ */
+
+static int from_msg_param_tmp_mem(struct tee_param *p, u32 attr,
+				  const struct optee_msg_param *mp)
+{
+	struct tee_shm *shm;
+	phys_addr_t pa;
+	int rc;
+
+	p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT +
+		  attr - OPTEE_MSG_ATTR_TYPE_TMEM_INPUT;
+	p->u.memref.size = mp->u.tmem.size;
+	shm = (struct tee_shm *)(unsigned long)mp->u.tmem.shm_ref;
+	if (!shm) {
+		p->u.memref.shm_offs = 0;
+		p->u.memref.shm = NULL;
+		return 0;
+	}
+
+	rc = tee_shm_get_pa(shm, 0, &pa);
+	if (rc)
+		return rc;
+
+	p->u.memref.shm_offs = mp->u.tmem.buf_ptr - pa;
+	p->u.memref.shm = shm;
+
+	return 0;
+}
+
+static void from_msg_param_reg_mem(struct tee_param *p, u32 attr,
+				   const struct optee_msg_param *mp)
+{
+	struct tee_shm *shm;
+
+	p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT +
+		  attr - OPTEE_MSG_ATTR_TYPE_RMEM_INPUT;
+	p->u.memref.size = mp->u.rmem.size;
+	shm = (struct tee_shm *)(unsigned long)mp->u.rmem.shm_ref;
+
+	if (shm) {
+		p->u.memref.shm_offs = mp->u.rmem.offs;
+		p->u.memref.shm = shm;
+	} else {
+		p->u.memref.shm_offs = 0;
+		p->u.memref.shm = NULL;
+	}
+}
+
+/**
+ * optee_from_msg_param() - convert from OPTEE_MSG parameters to
+ *			    struct tee_param
+ * @optee:	main service struct
+ * @params:	subsystem internal parameter representation
+ * @num_params:	number of elements in the parameter arrays
+ * @msg_params:	OPTEE_MSG parameters
+ * Returns 0 on success or <0 on failure
+ */
+static int optee_from_msg_param(struct optee *optee, struct tee_param *params,
+				size_t num_params,
+				const struct optee_msg_param *msg_params)
+{
+	int rc;
+	size_t n;
+
+	for (n = 0; n < num_params; n++) {
+		struct tee_param *p = params + n;
+		const struct optee_msg_param *mp = msg_params + n;
+		u32 attr = mp->attr & OPTEE_MSG_ATTR_TYPE_MASK;
+
+		switch (attr) {
+		case OPTEE_MSG_ATTR_TYPE_NONE:
+			p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_NONE;
+			memset(&p->u, 0, sizeof(p->u));
+			break;
+		case OPTEE_MSG_ATTR_TYPE_VALUE_INPUT:
+		case OPTEE_MSG_ATTR_TYPE_VALUE_OUTPUT:
+		case OPTEE_MSG_ATTR_TYPE_VALUE_INOUT:
+			optee_from_msg_param_value(p, attr, mp);
+			break;
+		case OPTEE_MSG_ATTR_TYPE_TMEM_INPUT:
+		case OPTEE_MSG_ATTR_TYPE_TMEM_OUTPUT:
+		case OPTEE_MSG_ATTR_TYPE_TMEM_INOUT:
+			rc = from_msg_param_tmp_mem(p, attr, mp);
+			if (rc)
+				return rc;
+			break;
+		case OPTEE_MSG_ATTR_TYPE_RMEM_INPUT:
+		case OPTEE_MSG_ATTR_TYPE_RMEM_OUTPUT:
+		case OPTEE_MSG_ATTR_TYPE_RMEM_INOUT:
+			from_msg_param_reg_mem(p, attr, mp);
+			break;
+
+		default:
+			return -EINVAL;
+		}
+	}
+	return 0;
+}
+
+static int to_msg_param_tmp_mem(struct optee_msg_param *mp,
+				const struct tee_param *p)
+{
+	int rc;
+	phys_addr_t pa;
+
+	mp->attr = OPTEE_MSG_ATTR_TYPE_TMEM_INPUT + p->attr -
+		   TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT;
+
+	mp->u.tmem.shm_ref = (unsigned long)p->u.memref.shm;
+	mp->u.tmem.size = p->u.memref.size;
+
+	if (!p->u.memref.shm) {
+		mp->u.tmem.buf_ptr = 0;
+		return 0;
+	}
+
+	rc = tee_shm_get_pa(p->u.memref.shm, p->u.memref.shm_offs, &pa);
+	if (rc)
+		return rc;
+
+	mp->u.tmem.buf_ptr = pa;
+	mp->attr |= OPTEE_MSG_ATTR_CACHE_PREDEFINED <<
+		    OPTEE_MSG_ATTR_CACHE_SHIFT;
+
+	return 0;
+}
+
+static int to_msg_param_reg_mem(struct optee_msg_param *mp,
+				const struct tee_param *p)
+{
+	mp->attr = OPTEE_MSG_ATTR_TYPE_RMEM_INPUT + p->attr -
+		   TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT;
+
+	mp->u.rmem.shm_ref = (unsigned long)p->u.memref.shm;
+	mp->u.rmem.size = p->u.memref.size;
+	mp->u.rmem.offs = p->u.memref.shm_offs;
+	return 0;
+}
+
+/**
+ * optee_to_msg_param() - convert from struct tee_params to OPTEE_MSG parameters
+ * @optee:	main service struct
+ * @msg_params:	OPTEE_MSG parameters
+ * @num_params:	number of elements in the parameter arrays
+ * @params:	subsystem itnernal parameter representation
+ * Returns 0 on success or <0 on failure
+ */
+static int optee_to_msg_param(struct optee *optee,
+			      struct optee_msg_param *msg_params,
+			      size_t num_params, const struct tee_param *params)
+{
+	int rc;
+	size_t n;
+
+	for (n = 0; n < num_params; n++) {
+		const struct tee_param *p = params + n;
+		struct optee_msg_param *mp = msg_params + n;
+
+		switch (p->attr) {
+		case TEE_IOCTL_PARAM_ATTR_TYPE_NONE:
+			mp->attr = TEE_IOCTL_PARAM_ATTR_TYPE_NONE;
+			memset(&mp->u, 0, sizeof(mp->u));
+			break;
+		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT:
+		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT:
+		case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
+			optee_to_msg_param_value(mp, p);
+			break;
+		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 (tee_shm_is_dynamic(p->u.memref.shm))
+				rc = to_msg_param_reg_mem(mp, p);
+			else
+				rc = to_msg_param_tmp_mem(mp, p);
+			if (rc)
+				return rc;
+			break;
+		default:
+			return -EINVAL;
+		}
+	}
+	return 0;
+}
+
+/*
+ * 2. Low level support functions to register shared memory in secure world
+ *
+ * Functions to enable/disable shared memory caching in secure world, that
+ * is, lazy freeing of previously allocated shared memory. Freeing is
+ * performed when a request has been compled.
+ *
+ * Functions to register and unregister shared memory both for normal
+ * clients and for tee-supplicant.
+ */
+
+/**
+ * optee_enable_shm_cache() - Enables caching of some shared memory allocation
+ *			      in OP-TEE
+ * @optee:	main service struct
+ */
+static void optee_enable_shm_cache(struct optee *optee)
+{
+	struct optee_call_waiter w;
+
+	/* We need to retry until secure world isn't busy. */
+	optee_cq_wait_init(&optee->call_queue, &w);
+	while (true) {
+		struct arm_smccc_res res;
+
+		optee->smc.invoke_fn(OPTEE_SMC_ENABLE_SHM_CACHE,
+				     0, 0, 0, 0, 0, 0, 0, &res);
+		if (res.a0 == OPTEE_SMC_RETURN_OK)
+			break;
+		optee_cq_wait_for_completion(&optee->call_queue, &w);
+	}
+	optee_cq_wait_final(&optee->call_queue, &w);
+}
+
+/**
+ * __optee_disable_shm_cache() - Disables caching of some shared memory
+ *				 allocation in OP-TEE
+ * @optee:	main service struct
+ * @is_mapped:	true if the cached shared memory addresses were mapped by this
+ *		kernel, are safe to dereference, and should be freed
+ */
+static void __optee_disable_shm_cache(struct optee *optee, bool is_mapped)
+{
+	struct optee_call_waiter w;
+
+	/* We need to retry until secure world isn't busy. */
+	optee_cq_wait_init(&optee->call_queue, &w);
+	while (true) {
+		union {
+			struct arm_smccc_res smccc;
+			struct optee_smc_disable_shm_cache_result result;
+		} res;
+
+		optee->smc.invoke_fn(OPTEE_SMC_DISABLE_SHM_CACHE,
+				     0, 0, 0, 0, 0, 0, 0, &res.smccc);
+		if (res.result.status == OPTEE_SMC_RETURN_ENOTAVAIL)
+			break; /* All shm's freed */
+		if (res.result.status == OPTEE_SMC_RETURN_OK) {
+			struct tee_shm *shm;
+
+			/*
+			 * Shared memory references that were not mapped by
+			 * this kernel must be ignored to prevent a crash.
+			 */
+			if (!is_mapped)
+				continue;
+
+			shm = reg_pair_to_ptr(res.result.shm_upper32,
+					      res.result.shm_lower32);
+			tee_shm_free(shm);
+		} else {
+			optee_cq_wait_for_completion(&optee->call_queue, &w);
+		}
+	}
+	optee_cq_wait_final(&optee->call_queue, &w);
+}
+
+/**
+ * optee_disable_shm_cache() - Disables caching of mapped shared memory
+ *			       allocations in OP-TEE
+ * @optee:	main service struct
+ */
+static void optee_disable_shm_cache(struct optee *optee)
+{
+	return __optee_disable_shm_cache(optee, true);
+}
+
+/**
+ * optee_disable_unmapped_shm_cache() - Disables caching of shared memory
+ *					allocations in OP-TEE which are not
+ *					currently mapped
+ * @optee:	main service struct
+ */
+static void optee_disable_unmapped_shm_cache(struct optee *optee)
+{
+	return __optee_disable_shm_cache(optee, false);
+}
+
+#define PAGELIST_ENTRIES_PER_PAGE				\
+	((OPTEE_MSG_NONCONTIG_PAGE_SIZE / sizeof(u64)) - 1)
+
+/*
+ * The final entry in each pagelist page is a pointer to the next
+ * pagelist page.
+ */
+static size_t get_pages_list_size(size_t num_entries)
+{
+	int pages = DIV_ROUND_UP(num_entries, PAGELIST_ENTRIES_PER_PAGE);
+
+	return pages * OPTEE_MSG_NONCONTIG_PAGE_SIZE;
+}
+
+static u64 *optee_allocate_pages_list(size_t num_entries)
+{
+	return alloc_pages_exact(get_pages_list_size(num_entries), GFP_KERNEL);
+}
+
+static void optee_free_pages_list(void *list, size_t num_entries)
+{
+	free_pages_exact(list, get_pages_list_size(num_entries));
+}
+
+/**
+ * optee_fill_pages_list() - write list of user pages to given shared
+ * buffer.
+ *
+ * @dst: page-aligned buffer where list of pages will be stored
+ * @pages: array of pages that represents shared buffer
+ * @num_pages: number of entries in @pages
+ * @page_offset: offset of user buffer from page start
+ *
+ * @dst should be big enough to hold list of user page addresses and
+ *	links to the next pages of buffer
+ */
+static void optee_fill_pages_list(u64 *dst, struct page **pages, int num_pages,
+				  size_t page_offset)
+{
+	int n = 0;
+	phys_addr_t optee_page;
+	/*
+	 * Refer to OPTEE_MSG_ATTR_NONCONTIG description in optee_msg.h
+	 * for details.
+	 */
+	struct {
+		u64 pages_list[PAGELIST_ENTRIES_PER_PAGE];
+		u64 next_page_data;
+	} *pages_data;
+
+	/*
+	 * Currently OP-TEE uses 4k page size and it does not looks
+	 * like this will change in the future.  On other hand, there are
+	 * no know ARM architectures with page size < 4k.
+	 * Thus the next built assert looks redundant. But the following
+	 * code heavily relies on this assumption, so it is better be
+	 * safe than sorry.
+	 */
+	BUILD_BUG_ON(PAGE_SIZE < OPTEE_MSG_NONCONTIG_PAGE_SIZE);
+
+	pages_data = (void *)dst;
+	/*
+	 * If linux page is bigger than 4k, and user buffer offset is
+	 * larger than 4k/8k/12k/etc this will skip first 4k pages,
+	 * because they bear no value data for OP-TEE.
+	 */
+	optee_page = page_to_phys(*pages) +
+		round_down(page_offset, OPTEE_MSG_NONCONTIG_PAGE_SIZE);
+
+	while (true) {
+		pages_data->pages_list[n++] = optee_page;
+
+		if (n == PAGELIST_ENTRIES_PER_PAGE) {
+			pages_data->next_page_data =
+				virt_to_phys(pages_data + 1);
+			pages_data++;
+			n = 0;
+		}
+
+		optee_page += OPTEE_MSG_NONCONTIG_PAGE_SIZE;
+		if (!(optee_page & ~PAGE_MASK)) {
+			if (!--num_pages)
+				break;
+			pages++;
+			optee_page = page_to_phys(*pages);
+		}
+	}
+}
+
+static int optee_shm_register(struct tee_context *ctx, struct tee_shm *shm,
+			      struct page **pages, size_t num_pages,
+			      unsigned long start)
+{
+	struct optee *optee = tee_get_drvdata(ctx->teedev);
+	struct optee_msg_arg *msg_arg;
+	struct tee_shm *shm_arg;
+	u64 *pages_list;
+	size_t sz;
+	int rc;
+
+	if (!num_pages)
+		return -EINVAL;
+
+	rc = optee_check_mem_type(start, num_pages);
+	if (rc)
+		return rc;
+
+	pages_list = optee_allocate_pages_list(num_pages);
+	if (!pages_list)
+		return -ENOMEM;
+
+	/*
+	 * We're about to register shared memory we can't register shared
+	 * memory for this request or there's a catch-22.
+	 *
+	 * So in this we'll have to do the good old temporary private
+	 * allocation instead of using optee_get_msg_arg().
+	 */
+	sz = optee_msg_arg_size(optee->rpc_param_count);
+	shm_arg = tee_shm_alloc_priv_buf(ctx, sz);
+	if (IS_ERR(shm_arg)) {
+		rc = PTR_ERR(shm_arg);
+		goto out;
+	}
+	msg_arg = tee_shm_get_va(shm_arg, 0);
+	if (IS_ERR(msg_arg)) {
+		rc = PTR_ERR(msg_arg);
+		goto out;
+	}
+
+	optee_fill_pages_list(pages_list, pages, num_pages,
+			      tee_shm_get_page_offset(shm));
+
+	memset(msg_arg, 0, OPTEE_MSG_GET_ARG_SIZE(1));
+	msg_arg->num_params = 1;
+	msg_arg->cmd = OPTEE_MSG_CMD_REGISTER_SHM;
+	msg_arg->params->attr = OPTEE_MSG_ATTR_TYPE_TMEM_OUTPUT |
+				OPTEE_MSG_ATTR_NONCONTIG;
+	msg_arg->params->u.tmem.shm_ref = (unsigned long)shm;
+	msg_arg->params->u.tmem.size = tee_shm_get_size(shm);
+	/*
+	 * In the least bits of msg_arg->params->u.tmem.buf_ptr we
+	 * store buffer offset from 4k page, as described in OP-TEE ABI.
+	 */
+	msg_arg->params->u.tmem.buf_ptr = virt_to_phys(pages_list) |
+	  (tee_shm_get_page_offset(shm) & (OPTEE_MSG_NONCONTIG_PAGE_SIZE - 1));
+
+	if (optee->ops->do_call_with_arg(ctx, shm_arg, 0) ||
+	    msg_arg->ret != TEEC_SUCCESS)
+		rc = -EINVAL;
+
+	tee_shm_free(shm_arg);
+out:
+	optee_free_pages_list(pages_list, num_pages);
+	return rc;
+}
+
+static int optee_shm_unregister(struct tee_context *ctx, struct tee_shm *shm)
+{
+	struct optee *optee = tee_get_drvdata(ctx->teedev);
+	struct optee_msg_arg *msg_arg;
+	struct tee_shm *shm_arg;
+	int rc = 0;
+	size_t sz;
+
+	/*
+	 * We're about to unregister shared memory and we may not be able
+	 * register shared memory for this request in case we're called
+	 * from optee_shm_arg_cache_uninit().
+	 *
+	 * So in order to keep things simple in this function just as in
+	 * optee_shm_register() we'll use temporary private allocation
+	 * instead of using optee_get_msg_arg().
+	 */
+	sz = optee_msg_arg_size(optee->rpc_param_count);
+	shm_arg = tee_shm_alloc_priv_buf(ctx, sz);
+	if (IS_ERR(shm_arg))
+		return PTR_ERR(shm_arg);
+	msg_arg = tee_shm_get_va(shm_arg, 0);
+	if (IS_ERR(msg_arg)) {
+		rc = PTR_ERR(msg_arg);
+		goto out;
+	}
+
+	memset(msg_arg, 0, sz);
+	msg_arg->num_params = 1;
+	msg_arg->cmd = OPTEE_MSG_CMD_UNREGISTER_SHM;
+	msg_arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_RMEM_INPUT;
+	msg_arg->params[0].u.rmem.shm_ref = (unsigned long)shm;
+
+	if (optee->ops->do_call_with_arg(ctx, shm_arg, 0) ||
+	    msg_arg->ret != TEEC_SUCCESS)
+		rc = -EINVAL;
+out:
+	tee_shm_free(shm_arg);
+	return rc;
+}
+
+static int optee_shm_register_supp(struct tee_context *ctx, struct tee_shm *shm,
+				   struct page **pages, size_t num_pages,
+				   unsigned long start)
+{
+	/*
+	 * We don't want to register supplicant memory in OP-TEE.
+	 * Instead information about it will be passed in RPC code.
+	 */
+	return optee_check_mem_type(start, num_pages);
+}
+
+static int optee_shm_unregister_supp(struct tee_context *ctx,
+				     struct tee_shm *shm)
+{
+	return 0;
+}
+
+/*
+ * 3. Dynamic shared memory pool based on alloc_pages()
+ *
+ * Implements an OP-TEE specific shared memory pool which is used
+ * when dynamic shared memory is supported by secure world.
+ *
+ * The main function is optee_shm_pool_alloc_pages().
+ */
+
+static int pool_op_alloc(struct tee_shm_pool *pool,
+			 struct tee_shm *shm, size_t size, size_t align)
+{
+	/*
+	 * Shared memory private to the OP-TEE driver doesn't need
+	 * to be registered with OP-TEE.
+	 */
+	if (shm->flags & TEE_SHM_PRIV)
+		return optee_pool_op_alloc_helper(pool, shm, size, align, NULL);
+
+	return optee_pool_op_alloc_helper(pool, shm, size, align,
+					  optee_shm_register);
+}
+
+static void pool_op_free(struct tee_shm_pool *pool,
+			 struct tee_shm *shm)
+{
+	if (!(shm->flags & TEE_SHM_PRIV))
+		optee_pool_op_free_helper(pool, shm, optee_shm_unregister);
+	else
+		optee_pool_op_free_helper(pool, shm, NULL);
+}
+
+static void pool_op_destroy_pool(struct tee_shm_pool *pool)
+{
+	kfree(pool);
+}
+
+static const struct tee_shm_pool_ops pool_ops = {
+	.alloc = pool_op_alloc,
+	.free = pool_op_free,
+	.destroy_pool = pool_op_destroy_pool,
+};
+
+/**
+ * optee_shm_pool_alloc_pages() - create page-based allocator pool
+ *
+ * This pool is used when OP-TEE supports dymanic SHM. In this case
+ * command buffers and such are allocated from kernel's own memory.
+ */
+static struct tee_shm_pool *optee_shm_pool_alloc_pages(void)
+{
+	struct tee_shm_pool *pool = kzalloc(sizeof(*pool), GFP_KERNEL);
+
+	if (!pool)
+		return ERR_PTR(-ENOMEM);
+
+	pool->ops = &pool_ops;
+
+	return pool;
+}
+
+/*
+ * 4. Do a normal scheduled call into secure world
+ *
+ * The function optee_smc_do_call_with_arg() performs a normal scheduled
+ * call into secure world. During this call may normal world request help
+ * from normal world using RPCs, Remote Procedure Calls. This includes
+ * delivery of non-secure interrupts to for instance allow rescheduling of
+ * the current task.
+ */
+
+static void handle_rpc_func_cmd_shm_free(struct tee_context *ctx,
+					 struct optee_msg_arg *arg)
+{
+	struct tee_shm *shm;
+
+	arg->ret_origin = TEEC_ORIGIN_COMMS;
+
+	if (arg->num_params != 1 ||
+	    arg->params[0].attr != OPTEE_MSG_ATTR_TYPE_VALUE_INPUT) {
+		arg->ret = TEEC_ERROR_BAD_PARAMETERS;
+		return;
+	}
+
+	shm = (struct tee_shm *)(unsigned long)arg->params[0].u.value.b;
+	switch (arg->params[0].u.value.a) {
+	case OPTEE_RPC_SHM_TYPE_APPL:
+		optee_rpc_cmd_free_suppl(ctx, shm);
+		break;
+	case OPTEE_RPC_SHM_TYPE_KERNEL:
+		tee_shm_free(shm);
+		break;
+	default:
+		arg->ret = TEEC_ERROR_BAD_PARAMETERS;
+	}
+	arg->ret = TEEC_SUCCESS;
+}
+
+static void handle_rpc_func_cmd_shm_alloc(struct tee_context *ctx,
+					  struct optee *optee,
+					  struct optee_msg_arg *arg,
+					  struct optee_call_ctx *call_ctx)
+{
+	phys_addr_t pa;
+	struct tee_shm *shm;
+	size_t sz;
+	size_t n;
+
+	arg->ret_origin = TEEC_ORIGIN_COMMS;
+
+	if (!arg->num_params ||
+	    arg->params[0].attr != OPTEE_MSG_ATTR_TYPE_VALUE_INPUT) {
+		arg->ret = TEEC_ERROR_BAD_PARAMETERS;
+		return;
+	}
+
+	for (n = 1; n < arg->num_params; n++) {
+		if (arg->params[n].attr != OPTEE_MSG_ATTR_TYPE_NONE) {
+			arg->ret = TEEC_ERROR_BAD_PARAMETERS;
+			return;
+		}
+	}
+
+	sz = arg->params[0].u.value.b;
+	switch (arg->params[0].u.value.a) {
+	case OPTEE_RPC_SHM_TYPE_APPL:
+		shm = optee_rpc_cmd_alloc_suppl(ctx, sz);
+		break;
+	case OPTEE_RPC_SHM_TYPE_KERNEL:
+		shm = tee_shm_alloc_priv_buf(optee->ctx, sz);
+		break;
+	default:
+		arg->ret = TEEC_ERROR_BAD_PARAMETERS;
+		return;
+	}
+
+	if (IS_ERR(shm)) {
+		arg->ret = TEEC_ERROR_OUT_OF_MEMORY;
+		return;
+	}
+
+	if (tee_shm_get_pa(shm, 0, &pa)) {
+		arg->ret = TEEC_ERROR_BAD_PARAMETERS;
+		goto bad;
+	}
+
+	sz = tee_shm_get_size(shm);
+
+	if (tee_shm_is_dynamic(shm)) {
+		struct page **pages;
+		u64 *pages_list;
+		size_t page_num;
+
+		pages = tee_shm_get_pages(shm, &page_num);
+		if (!pages || !page_num) {
+			arg->ret = TEEC_ERROR_OUT_OF_MEMORY;
+			goto bad;
+		}
+
+		pages_list = optee_allocate_pages_list(page_num);
+		if (!pages_list) {
+			arg->ret = TEEC_ERROR_OUT_OF_MEMORY;
+			goto bad;
+		}
+
+		call_ctx->pages_list = pages_list;
+		call_ctx->num_entries = page_num;
+
+		arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_TMEM_OUTPUT |
+				      OPTEE_MSG_ATTR_NONCONTIG;
+		/*
+		 * In the least bits of u.tmem.buf_ptr we store buffer offset
+		 * from 4k page, as described in OP-TEE ABI.
+		 */
+		arg->params[0].u.tmem.buf_ptr = virt_to_phys(pages_list) |
+			(tee_shm_get_page_offset(shm) &
+			 (OPTEE_MSG_NONCONTIG_PAGE_SIZE - 1));
+		arg->params[0].u.tmem.size = tee_shm_get_size(shm);
+		arg->params[0].u.tmem.shm_ref = (unsigned long)shm;
+
+		optee_fill_pages_list(pages_list, pages, page_num,
+				      tee_shm_get_page_offset(shm));
+	} else {
+		arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_TMEM_OUTPUT;
+		arg->params[0].u.tmem.buf_ptr = pa;
+		arg->params[0].u.tmem.size = sz;
+		arg->params[0].u.tmem.shm_ref = (unsigned long)shm;
+	}
+
+	arg->ret = TEEC_SUCCESS;
+	return;
+bad:
+	tee_shm_free(shm);
+}
+
+static void free_pages_list(struct optee_call_ctx *call_ctx)
+{
+	if (call_ctx->pages_list) {
+		optee_free_pages_list(call_ctx->pages_list,
+				      call_ctx->num_entries);
+		call_ctx->pages_list = NULL;
+		call_ctx->num_entries = 0;
+	}
+}
+
+static void optee_rpc_finalize_call(struct optee_call_ctx *call_ctx)
+{
+	free_pages_list(call_ctx);
+}
+
+static void handle_rpc_func_cmd(struct tee_context *ctx, struct optee *optee,
+				struct optee_msg_arg *arg,
+				struct optee_call_ctx *call_ctx)
+{
+
+	switch (arg->cmd) {
+	case OPTEE_RPC_CMD_SHM_ALLOC:
+		free_pages_list(call_ctx);
+		handle_rpc_func_cmd_shm_alloc(ctx, optee, arg, call_ctx);
+		break;
+	case OPTEE_RPC_CMD_SHM_FREE:
+		handle_rpc_func_cmd_shm_free(ctx, arg);
+		break;
+	default:
+		optee_rpc_cmd(ctx, optee, arg);
+	}
+}
+
+/**
+ * optee_handle_rpc() - handle RPC from secure world
+ * @ctx:	context doing the RPC
+ * @param:	value of registers for the RPC
+ * @call_ctx:	call context. Preserved during one OP-TEE invocation
+ *
+ * Result of RPC is written back into @param.
+ */
+static void optee_handle_rpc(struct tee_context *ctx,
+			     struct optee_msg_arg *rpc_arg,
+			     struct optee_rpc_param *param,
+			     struct optee_call_ctx *call_ctx)
+{
+	struct tee_device *teedev = ctx->teedev;
+	struct optee *optee = tee_get_drvdata(teedev);
+	struct optee_msg_arg *arg;
+	struct tee_shm *shm;
+	phys_addr_t pa;
+
+	switch (OPTEE_SMC_RETURN_GET_RPC_FUNC(param->a0)) {
+	case OPTEE_SMC_RPC_FUNC_ALLOC:
+		shm = tee_shm_alloc_priv_buf(optee->ctx, param->a1);
+		if (!IS_ERR(shm) && !tee_shm_get_pa(shm, 0, &pa)) {
+			reg_pair_from_64(&param->a1, &param->a2, pa);
+			reg_pair_from_64(&param->a4, &param->a5,
+					 (unsigned long)shm);
+		} else {
+			param->a1 = 0;
+			param->a2 = 0;
+			param->a4 = 0;
+			param->a5 = 0;
+		}
+		kmemleak_not_leak(shm);
+		break;
+	case OPTEE_SMC_RPC_FUNC_FREE:
+		shm = reg_pair_to_ptr(param->a1, param->a2);
+		tee_shm_free(shm);
+		break;
+	case OPTEE_SMC_RPC_FUNC_FOREIGN_INTR:
+		/*
+		 * A foreign interrupt was raised while secure world was
+		 * executing, since they are handled in Linux a dummy RPC is
+		 * performed to let Linux take the interrupt through the normal
+		 * vector.
+		 */
+		break;
+	case OPTEE_SMC_RPC_FUNC_CMD:
+		if (rpc_arg) {
+			arg = rpc_arg;
+		} else {
+			shm = reg_pair_to_ptr(param->a1, param->a2);
+			arg = tee_shm_get_va(shm, 0);
+			if (IS_ERR(arg)) {
+				pr_err("%s: tee_shm_get_va %p failed\n",
+				       __func__, shm);
+				break;
+			}
+		}
+
+		handle_rpc_func_cmd(ctx, optee, arg, call_ctx);
+		break;
+	default:
+		pr_warn("Unknown RPC func 0x%x\n",
+			(u32)OPTEE_SMC_RETURN_GET_RPC_FUNC(param->a0));
+		break;
+	}
+
+	param->a0 = OPTEE_SMC_CALL_RETURN_FROM_RPC;
+}
+
+/**
+ * optee_smc_do_call_with_arg() - Do an SMC to OP-TEE in secure world
+ * @ctx:	calling context
+ * @shm:	shared memory holding the message to pass to secure world
+ * @offs:	offset of the message in @shm
+ *
+ * Does and SMC to OP-TEE in secure world and handles eventual resulting
+ * Remote Procedure Calls (RPC) from OP-TEE.
+ *
+ * Returns return code from secure world, 0 is OK
+ */
+static int optee_smc_do_call_with_arg(struct tee_context *ctx,
+				      struct tee_shm *shm, u_int offs)
+{
+	struct optee *optee = tee_get_drvdata(ctx->teedev);
+	struct optee_call_waiter w;
+	struct optee_rpc_param param = { };
+	struct optee_call_ctx call_ctx = { };
+	struct optee_msg_arg *rpc_arg = NULL;
+	int rc;
+
+	if (optee->rpc_param_count) {
+		struct optee_msg_arg *arg;
+		unsigned int rpc_arg_offs;
+
+		arg = tee_shm_get_va(shm, offs);
+		if (IS_ERR(arg))
+			return PTR_ERR(arg);
+
+		rpc_arg_offs = OPTEE_MSG_GET_ARG_SIZE(arg->num_params);
+		rpc_arg = tee_shm_get_va(shm, offs + rpc_arg_offs);
+		if (IS_ERR(rpc_arg))
+			return PTR_ERR(rpc_arg);
+	}
+
+	if  (rpc_arg && tee_shm_is_dynamic(shm)) {
+		param.a0 = OPTEE_SMC_CALL_WITH_REGD_ARG;
+		reg_pair_from_64(&param.a1, &param.a2, (u_long)shm);
+		param.a3 = offs;
+	} else {
+		phys_addr_t parg;
+
+		rc = tee_shm_get_pa(shm, offs, &parg);
+		if (rc)
+			return rc;
+
+		if (rpc_arg)
+			param.a0 = OPTEE_SMC_CALL_WITH_RPC_ARG;
+		else
+			param.a0 = OPTEE_SMC_CALL_WITH_ARG;
+		reg_pair_from_64(&param.a1, &param.a2, parg);
+	}
+	/* Initialize waiter */
+	optee_cq_wait_init(&optee->call_queue, &w);
+	while (true) {
+		struct arm_smccc_res res;
+
+		trace_optee_invoke_fn_begin(&param);
+		optee->smc.invoke_fn(param.a0, param.a1, param.a2, param.a3,
+				     param.a4, param.a5, param.a6, param.a7,
+				     &res);
+		trace_optee_invoke_fn_end(&param, &res);
+
+		if (res.a0 == OPTEE_SMC_RETURN_ETHREAD_LIMIT) {
+			/*
+			 * Out of threads in secure world, wait for a thread
+			 * become available.
+			 */
+			optee_cq_wait_for_completion(&optee->call_queue, &w);
+		} else if (OPTEE_SMC_RETURN_IS_RPC(res.a0)) {
+			cond_resched();
+			param.a0 = res.a0;
+			param.a1 = res.a1;
+			param.a2 = res.a2;
+			param.a3 = res.a3;
+			optee_handle_rpc(ctx, rpc_arg, &param, &call_ctx);
+		} else {
+			rc = res.a0;
+			break;
+		}
+	}
+
+	optee_rpc_finalize_call(&call_ctx);
+	/*
+	 * We're done with our thread in secure world, if there's any
+	 * thread waiters wake up one.
+	 */
+	optee_cq_wait_final(&optee->call_queue, &w);
+
+	return rc;
+}
+
+static int simple_call_with_arg(struct tee_context *ctx, u32 cmd)
+{
+	struct optee_shm_arg_entry *entry;
+	struct optee_msg_arg *msg_arg;
+	struct tee_shm *shm;
+	u_int offs;
+
+	msg_arg = optee_get_msg_arg(ctx, 0, &entry, &shm, &offs);
+	if (IS_ERR(msg_arg))
+		return PTR_ERR(msg_arg);
+
+	msg_arg->cmd = cmd;
+	optee_smc_do_call_with_arg(ctx, shm, offs);
+
+	optee_free_msg_arg(ctx, entry, offs);
+	return 0;
+}
+
+static int optee_smc_do_bottom_half(struct tee_context *ctx)
+{
+	return simple_call_with_arg(ctx, OPTEE_MSG_CMD_DO_BOTTOM_HALF);
+}
+
+static int optee_smc_stop_async_notif(struct tee_context *ctx)
+{
+	return simple_call_with_arg(ctx, OPTEE_MSG_CMD_STOP_ASYNC_NOTIF);
+}
+
+/*
+ * 5. Asynchronous notification
+ */
+
+static u32 get_async_notif_value(optee_invoke_fn *invoke_fn, bool *value_valid,
+				 bool *value_pending)
+{
+	struct arm_smccc_res res;
+
+	invoke_fn(OPTEE_SMC_GET_ASYNC_NOTIF_VALUE, 0, 0, 0, 0, 0, 0, 0, &res);
+
+	if (res.a0) {
+		*value_valid = false;
+		return 0;
+	}
+	*value_valid = (res.a2 & OPTEE_SMC_ASYNC_NOTIF_VALUE_VALID);
+	*value_pending = (res.a2 & OPTEE_SMC_ASYNC_NOTIF_VALUE_PENDING);
+	return res.a1;
+}
+
+static irqreturn_t notif_irq_handler(int irq, void *dev_id)
+{
+	struct optee *optee = dev_id;
+	bool do_bottom_half = false;
+	bool value_valid;
+	bool value_pending;
+	u32 value;
+
+	do {
+		value = get_async_notif_value(optee->smc.invoke_fn,
+					      &value_valid, &value_pending);
+		if (!value_valid)
+			break;
+
+		if (value == OPTEE_SMC_ASYNC_NOTIF_VALUE_DO_BOTTOM_HALF)
+			do_bottom_half = true;
+		else
+			optee_notif_send(optee, value);
+	} while (value_pending);
+
+	if (do_bottom_half)
+		return IRQ_WAKE_THREAD;
+	return IRQ_HANDLED;
+}
+
+static irqreturn_t notif_irq_thread_fn(int irq, void *dev_id)
+{
+	struct optee *optee = dev_id;
+
+	optee_smc_do_bottom_half(optee->ctx);
+
+	return IRQ_HANDLED;
+}
+
+static int optee_smc_notif_init_irq(struct optee *optee, u_int irq)
+{
+	int rc;
+
+	rc = request_threaded_irq(irq, notif_irq_handler,
+				  notif_irq_thread_fn,
+				  0, "optee_notification", optee);
+	if (rc)
+		return rc;
+
+	optee->smc.notif_irq = irq;
+
+	return 0;
+}
+
+static void optee_smc_notif_uninit_irq(struct optee *optee)
+{
+	if (optee->smc.sec_caps & OPTEE_SMC_SEC_CAP_ASYNC_NOTIF) {
+		optee_smc_stop_async_notif(optee->ctx);
+		if (optee->smc.notif_irq) {
+			free_irq(optee->smc.notif_irq, optee);
+			irq_dispose_mapping(optee->smc.notif_irq);
+		}
+	}
+}
+
+/*
+ * 6. Driver initialization
+ *
+ * During driver initialization is secure world probed to find out which
+ * features it supports so the driver can be initialized with a matching
+ * configuration. This involves for instance support for dynamic shared
+ * memory instead of a static memory carvout.
+ */
+
+static void optee_get_version(struct tee_device *teedev,
+			      struct tee_ioctl_version_data *vers)
+{
+	struct tee_ioctl_version_data v = {
+		.impl_id = TEE_IMPL_ID_OPTEE,
+		.impl_caps = TEE_OPTEE_CAP_TZ,
+		.gen_caps = TEE_GEN_CAP_GP,
+	};
+	struct optee *optee = tee_get_drvdata(teedev);
+
+	if (optee->smc.sec_caps & OPTEE_SMC_SEC_CAP_DYNAMIC_SHM)
+		v.gen_caps |= TEE_GEN_CAP_REG_MEM;
+	if (optee->smc.sec_caps & OPTEE_SMC_SEC_CAP_MEMREF_NULL)
+		v.gen_caps |= TEE_GEN_CAP_MEMREF_NULL;
+	*vers = v;
+}
+
+static int optee_smc_open(struct tee_context *ctx)
+{
+	struct optee *optee = tee_get_drvdata(ctx->teedev);
+	u32 sec_caps = optee->smc.sec_caps;
+
+	return optee_open(ctx, sec_caps & OPTEE_SMC_SEC_CAP_MEMREF_NULL);
+}
+
+static const struct tee_driver_ops optee_clnt_ops = {
+	.get_version = optee_get_version,
+	.open = optee_smc_open,
+	.release = optee_release,
+	.open_session = optee_open_session,
+	.close_session = optee_close_session,
+	.invoke_func = optee_invoke_func,
+	.cancel_req = optee_cancel_req,
+	.shm_register = optee_shm_register,
+	.shm_unregister = optee_shm_unregister,
+};
+
+static const struct tee_desc optee_clnt_desc = {
+	.name = DRIVER_NAME "-clnt",
+	.ops = &optee_clnt_ops,
+	.owner = THIS_MODULE,
+};
+
+static const struct tee_driver_ops optee_supp_ops = {
+	.get_version = optee_get_version,
+	.open = optee_smc_open,
+	.release = optee_release_supp,
+	.supp_recv = optee_supp_recv,
+	.supp_send = optee_supp_send,
+	.shm_register = optee_shm_register_supp,
+	.shm_unregister = optee_shm_unregister_supp,
+};
+
+static const struct tee_desc optee_supp_desc = {
+	.name = DRIVER_NAME "-supp",
+	.ops = &optee_supp_ops,
+	.owner = THIS_MODULE,
+	.flags = TEE_DESC_PRIVILEGED,
+};
+
+static const struct optee_ops optee_ops = {
+	.do_call_with_arg = optee_smc_do_call_with_arg,
+	.to_msg_param = optee_to_msg_param,
+	.from_msg_param = optee_from_msg_param,
+};
+
+static int enable_async_notif(optee_invoke_fn *invoke_fn)
+{
+	struct arm_smccc_res res;
+
+	invoke_fn(OPTEE_SMC_ENABLE_ASYNC_NOTIF, 0, 0, 0, 0, 0, 0, 0, &res);
+
+	if (res.a0)
+		return -EINVAL;
+	return 0;
+}
+
+static bool optee_msg_api_uid_is_optee_api(optee_invoke_fn *invoke_fn)
+{
+	struct arm_smccc_res res;
+
+	invoke_fn(OPTEE_SMC_CALLS_UID, 0, 0, 0, 0, 0, 0, 0, &res);
+
+	if (res.a0 == OPTEE_MSG_UID_0 && res.a1 == OPTEE_MSG_UID_1 &&
+	    res.a2 == OPTEE_MSG_UID_2 && res.a3 == OPTEE_MSG_UID_3)
+		return true;
+	return false;
+}
+
+static void optee_msg_get_os_revision(optee_invoke_fn *invoke_fn)
+{
+	union {
+		struct arm_smccc_res smccc;
+		struct optee_smc_call_get_os_revision_result result;
+	} res = {
+		.result = {
+			.build_id = 0
+		}
+	};
+
+	invoke_fn(OPTEE_SMC_CALL_GET_OS_REVISION, 0, 0, 0, 0, 0, 0, 0,
+		  &res.smccc);
+
+	if (res.result.build_id)
+		pr_info("revision %lu.%lu (%08lx)", res.result.major,
+			res.result.minor, res.result.build_id);
+	else
+		pr_info("revision %lu.%lu", res.result.major, res.result.minor);
+}
+
+static bool optee_msg_api_revision_is_compatible(optee_invoke_fn *invoke_fn)
+{
+	union {
+		struct arm_smccc_res smccc;
+		struct optee_smc_calls_revision_result result;
+	} res;
+
+	invoke_fn(OPTEE_SMC_CALLS_REVISION, 0, 0, 0, 0, 0, 0, 0, &res.smccc);
+
+	if (res.result.major == OPTEE_MSG_REVISION_MAJOR &&
+	    (int)res.result.minor >= OPTEE_MSG_REVISION_MINOR)
+		return true;
+	return false;
+}
+
+static bool optee_msg_exchange_capabilities(optee_invoke_fn *invoke_fn,
+					    u32 *sec_caps, u32 *max_notif_value,
+					    unsigned int *rpc_param_count)
+{
+	union {
+		struct arm_smccc_res smccc;
+		struct optee_smc_exchange_capabilities_result result;
+	} res;
+	u32 a1 = 0;
+
+	/*
+	 * TODO This isn't enough to tell if it's UP system (from kernel
+	 * point of view) or not, is_smp() returns the information
+	 * needed, but can't be called directly from here.
+	 */
+	if (!IS_ENABLED(CONFIG_SMP) || nr_cpu_ids == 1)
+		a1 |= OPTEE_SMC_NSEC_CAP_UNIPROCESSOR;
+
+	invoke_fn(OPTEE_SMC_EXCHANGE_CAPABILITIES, a1, 0, 0, 0, 0, 0, 0,
+		  &res.smccc);
+
+	if (res.result.status != OPTEE_SMC_RETURN_OK)
+		return false;
+
+	*sec_caps = res.result.capabilities;
+	if (*sec_caps & OPTEE_SMC_SEC_CAP_ASYNC_NOTIF)
+		*max_notif_value = res.result.max_notif_value;
+	else
+		*max_notif_value = OPTEE_DEFAULT_MAX_NOTIF_VALUE;
+	if (*sec_caps & OPTEE_SMC_SEC_CAP_RPC_ARG)
+		*rpc_param_count = (u8)res.result.data;
+	else
+		*rpc_param_count = 0;
+
+	return true;
+}
+
+static struct tee_shm_pool *
+optee_config_shm_memremap(optee_invoke_fn *invoke_fn, void **memremaped_shm)
+{
+	union {
+		struct arm_smccc_res smccc;
+		struct optee_smc_get_shm_config_result result;
+	} res;
+	unsigned long vaddr;
+	phys_addr_t paddr;
+	size_t size;
+	phys_addr_t begin;
+	phys_addr_t end;
+	void *va;
+	void *rc;
+
+	invoke_fn(OPTEE_SMC_GET_SHM_CONFIG, 0, 0, 0, 0, 0, 0, 0, &res.smccc);
+	if (res.result.status != OPTEE_SMC_RETURN_OK) {
+		pr_err("static shm service not available\n");
+		return ERR_PTR(-ENOENT);
+	}
+
+	if (res.result.settings != OPTEE_SMC_SHM_CACHED) {
+		pr_err("only normal cached shared memory supported\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	begin = roundup(res.result.start, PAGE_SIZE);
+	end = rounddown(res.result.start + res.result.size, PAGE_SIZE);
+	paddr = begin;
+	size = end - begin;
+
+	va = memremap(paddr, size, MEMREMAP_WB);
+	if (!va) {
+		pr_err("shared memory ioremap failed\n");
+		return ERR_PTR(-EINVAL);
+	}
+	vaddr = (unsigned long)va;
+
+	rc = tee_shm_pool_alloc_res_mem(vaddr, paddr, size,
+					OPTEE_MIN_STATIC_POOL_ALIGN);
+	if (IS_ERR(rc))
+		memunmap(va);
+	else
+		*memremaped_shm = va;
+
+	return rc;
+}
+
+/* Simple wrapper functions to be able to use a function pointer */
+static void optee_smccc_smc(unsigned long a0, unsigned long a1,
+			    unsigned long a2, unsigned long a3,
+			    unsigned long a4, unsigned long a5,
+			    unsigned long a6, unsigned long a7,
+			    struct arm_smccc_res *res)
+{
+	arm_smccc_smc(a0, a1, a2, a3, a4, a5, a6, a7, res);
+}
+
+static void optee_smccc_hvc(unsigned long a0, unsigned long a1,
+			    unsigned long a2, unsigned long a3,
+			    unsigned long a4, unsigned long a5,
+			    unsigned long a6, unsigned long a7,
+			    struct arm_smccc_res *res)
+{
+	arm_smccc_hvc(a0, a1, a2, a3, a4, a5, a6, a7, res);
+}
+
+static optee_invoke_fn *get_invoke_func(struct device *dev)
+{
+	const char *method;
+
+	pr_info("probing for conduit method.\n");
+
+	if (device_property_read_string(dev, "method", &method)) {
+		pr_warn("missing \"method\" property\n");
+		return ERR_PTR(-ENXIO);
+	}
+
+	if (!strcmp("hvc", method))
+		return optee_smccc_hvc;
+	else if (!strcmp("smc", method))
+		return optee_smccc_smc;
+
+	pr_warn("invalid \"method\" property: %s\n", method);
+	return ERR_PTR(-EINVAL);
+}
+
+/* optee_remove - Device Removal Routine
+ * @pdev: platform device information struct
+ *
+ * optee_remove is called by platform subsystem to alert the driver
+ * that it should release the device
+ */
+static int optee_smc_remove(struct platform_device *pdev)
+{
+	struct optee *optee = platform_get_drvdata(pdev);
+
+	/*
+	 * Ask OP-TEE to free all cached shared memory objects to decrease
+	 * reference counters and also avoid wild pointers in secure world
+	 * into the old shared memory range.
+	 */
+	if (!optee->rpc_param_count)
+		optee_disable_shm_cache(optee);
+
+	optee_smc_notif_uninit_irq(optee);
+
+	optee_remove_common(optee);
+
+	if (optee->smc.memremaped_shm)
+		memunmap(optee->smc.memremaped_shm);
+
+	kfree(optee);
+
+	return 0;
+}
+
+/* optee_shutdown - Device Removal Routine
+ * @pdev: platform device information struct
+ *
+ * platform_shutdown is called by the platform subsystem to alert
+ * the driver that a shutdown, reboot, or kexec is happening and
+ * device must be disabled.
+ */
+static void optee_shutdown(struct platform_device *pdev)
+{
+	struct optee *optee = platform_get_drvdata(pdev);
+
+	if (!optee->rpc_param_count)
+		optee_disable_shm_cache(optee);
+}
+
+static int optee_probe(struct platform_device *pdev)
+{
+	optee_invoke_fn *invoke_fn;
+	struct tee_shm_pool *pool = ERR_PTR(-EINVAL);
+	struct optee *optee = NULL;
+	void *memremaped_shm = NULL;
+	unsigned int rpc_param_count;
+	struct tee_device *teedev;
+	struct tee_context *ctx;
+	u32 max_notif_value;
+	u32 arg_cache_flags;
+	u32 sec_caps;
+	int rc;
+
+	invoke_fn = get_invoke_func(&pdev->dev);
+	if (IS_ERR(invoke_fn))
+		return PTR_ERR(invoke_fn);
+
+	if (!optee_msg_api_uid_is_optee_api(invoke_fn)) {
+		pr_warn("api uid mismatch\n");
+		return -EINVAL;
+	}
+
+	optee_msg_get_os_revision(invoke_fn);
+
+	if (!optee_msg_api_revision_is_compatible(invoke_fn)) {
+		pr_warn("api revision mismatch\n");
+		return -EINVAL;
+	}
+
+	if (!optee_msg_exchange_capabilities(invoke_fn, &sec_caps,
+					     &max_notif_value,
+					     &rpc_param_count)) {
+		pr_warn("capabilities mismatch\n");
+		return -EINVAL;
+	}
+
+	/*
+	 * Try to use dynamic shared memory if possible
+	 */
+	if (sec_caps & OPTEE_SMC_SEC_CAP_DYNAMIC_SHM) {
+		/*
+		 * If we have OPTEE_SMC_SEC_CAP_RPC_ARG we can ask
+		 * optee_get_msg_arg() to pre-register (by having
+		 * OPTEE_SHM_ARG_ALLOC_PRIV cleared) the page used to pass
+		 * an argument struct.
+		 *
+		 * With the page is pre-registered we can use a non-zero
+		 * offset for argument struct, this is indicated with
+		 * OPTEE_SHM_ARG_SHARED.
+		 *
+		 * This means that optee_smc_do_call_with_arg() will use
+		 * OPTEE_SMC_CALL_WITH_REGD_ARG for pre-registered pages.
+		 */
+		if (sec_caps & OPTEE_SMC_SEC_CAP_RPC_ARG)
+			arg_cache_flags = OPTEE_SHM_ARG_SHARED;
+		else
+			arg_cache_flags = OPTEE_SHM_ARG_ALLOC_PRIV;
+
+		pool = optee_shm_pool_alloc_pages();
+	}
+
+	/*
+	 * If dynamic shared memory is not available or failed - try static one
+	 */
+	if (IS_ERR(pool) && (sec_caps & OPTEE_SMC_SEC_CAP_HAVE_RESERVED_SHM)) {
+		/*
+		 * The static memory pool can use non-zero page offsets so
+		 * let optee_get_msg_arg() know that with OPTEE_SHM_ARG_SHARED.
+		 *
+		 * optee_get_msg_arg() should not pre-register the
+		 * allocated page used to pass an argument struct, this is
+		 * indicated with OPTEE_SHM_ARG_ALLOC_PRIV.
+		 *
+		 * This means that optee_smc_do_call_with_arg() will use
+		 * OPTEE_SMC_CALL_WITH_ARG if rpc_param_count is 0, else
+		 * OPTEE_SMC_CALL_WITH_RPC_ARG.
+		 */
+		arg_cache_flags = OPTEE_SHM_ARG_SHARED |
+				  OPTEE_SHM_ARG_ALLOC_PRIV;
+		pool = optee_config_shm_memremap(invoke_fn, &memremaped_shm);
+	}
+
+	if (IS_ERR(pool))
+		return PTR_ERR(pool);
+
+	optee = kzalloc(sizeof(*optee), GFP_KERNEL);
+	if (!optee) {
+		rc = -ENOMEM;
+		goto err_free_pool;
+	}
+
+	optee->ops = &optee_ops;
+	optee->smc.invoke_fn = invoke_fn;
+	optee->smc.sec_caps = sec_caps;
+	optee->rpc_param_count = rpc_param_count;
+
+	teedev = tee_device_alloc(&optee_clnt_desc, NULL, pool, optee);
+	if (IS_ERR(teedev)) {
+		rc = PTR_ERR(teedev);
+		goto err_free_optee;
+	}
+	optee->teedev = teedev;
+
+	teedev = tee_device_alloc(&optee_supp_desc, NULL, pool, optee);
+	if (IS_ERR(teedev)) {
+		rc = PTR_ERR(teedev);
+		goto err_unreg_teedev;
+	}
+	optee->supp_teedev = teedev;
+
+	rc = tee_device_register(optee->teedev);
+	if (rc)
+		goto err_unreg_supp_teedev;
+
+	rc = tee_device_register(optee->supp_teedev);
+	if (rc)
+		goto err_unreg_supp_teedev;
+
+	mutex_init(&optee->call_queue.mutex);
+	INIT_LIST_HEAD(&optee->call_queue.waiters);
+	optee_supp_init(&optee->supp);
+	optee->smc.memremaped_shm = memremaped_shm;
+	optee->pool = pool;
+	optee_shm_arg_cache_init(optee, arg_cache_flags);
+
+	platform_set_drvdata(pdev, optee);
+	ctx = teedev_open(optee->teedev);
+	if (IS_ERR(ctx)) {
+		rc = PTR_ERR(ctx);
+		goto err_supp_uninit;
+	}
+	optee->ctx = ctx;
+	rc = optee_notif_init(optee, max_notif_value);
+	if (rc)
+		goto err_close_ctx;
+
+	if (sec_caps & OPTEE_SMC_SEC_CAP_ASYNC_NOTIF) {
+		unsigned int irq;
+
+		rc = platform_get_irq(pdev, 0);
+		if (rc < 0) {
+			pr_err("platform_get_irq: ret %d\n", rc);
+			goto err_notif_uninit;
+		}
+		irq = rc;
+
+		rc = optee_smc_notif_init_irq(optee, irq);
+		if (rc) {
+			irq_dispose_mapping(irq);
+			goto err_notif_uninit;
+		}
+		enable_async_notif(optee->smc.invoke_fn);
+		pr_info("Asynchronous notifications enabled\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
+	 * address during shutdown. This could occur, for example, if we're
+	 * kexec booting from an older kernel that did not properly cleanup the
+	 * shm cache.
+	 */
+	optee_disable_unmapped_shm_cache(optee);
+
+	/*
+	 * Only enable the shm cache in case we're not able to pass the RPC
+	 * arg struct right after the normal arg struct.
+	 */
+	if (!optee->rpc_param_count)
+		optee_enable_shm_cache(optee);
+
+	if (optee->smc.sec_caps & OPTEE_SMC_SEC_CAP_DYNAMIC_SHM)
+		pr_info("dynamic shared memory is enabled\n");
+
+	rc = optee_enumerate_devices(PTA_CMD_GET_DEVICES);
+	if (rc)
+		goto err_disable_shm_cache;
+
+	pr_info("initialized driver\n");
+	return 0;
+
+err_disable_shm_cache:
+	if (!optee->rpc_param_count)
+		optee_disable_shm_cache(optee);
+	optee_smc_notif_uninit_irq(optee);
+	optee_unregister_devices();
+err_notif_uninit:
+	optee_notif_uninit(optee);
+err_close_ctx:
+	teedev_close_context(ctx);
+err_supp_uninit:
+	optee_shm_arg_cache_uninit(optee);
+	optee_supp_uninit(&optee->supp);
+	mutex_destroy(&optee->call_queue.mutex);
+err_unreg_supp_teedev:
+	tee_device_unregister(optee->supp_teedev);
+err_unreg_teedev:
+	tee_device_unregister(optee->teedev);
+err_free_optee:
+	kfree(optee);
+err_free_pool:
+	tee_shm_pool_free(pool);
+	if (memremaped_shm)
+		memunmap(memremaped_shm);
+	return rc;
+}
+
+static const struct of_device_id optee_dt_match[] = {
+	{ .compatible = "linaro,optee-tz" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, optee_dt_match);
+
+static struct platform_driver optee_driver = {
+	.probe  = optee_probe,
+	.remove = optee_smc_remove,
+	.shutdown = optee_shutdown,
+	.driver = {
+		.name = "optee",
+		.of_match_table = optee_dt_match,
+	},
+};
+
+int optee_smc_abi_register(void)
+{
+	return platform_driver_register(&optee_driver);
+}
+
+void optee_smc_abi_unregister(void)
+{
+	platform_driver_unregister(&optee_driver);
+}