optee: isolate smc abi

Isolate the ABI based on raw SMCs. Code specific to the raw SMC ABI is
moved into smc_abi.c. This makes room for other ABIs with a clear
separation.

The driver changes to use module_init()/module_exit() instead of
module_platform_driver(). The platform_driver_register() and
platform_driver_unregister() functions called directly to keep the same
behavior. This is needed because module_platform_driver() is based on
module_driver() which can only be used once in a module.

A function optee_rpc_cmd() is factored out from the function
handle_rpc_func_cmd() to handle the ABI independent part of RPC
processing.

This patch is not supposed to change the driver behavior, it's only a
matter of reorganizing the code.

Reviewed-by: Sumit Garg <sumit.garg@linaro.org>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>

1 files changed, 51 insertions, 670 deletions

diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c
index 26492d3115f5..27b855325b33 100644
--- a/drivers/tee/optee/core.c
+++ b/drivers/tee/optee/core.c
@@ -1,260 +1,71 @@
 // 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/crash_dump.h>
 #include <linux/errno.h>
 #include <linux/io.h>
+#include <linux/mm.h>
 #include <linux/module.h>
-#include <linux/of.h>
-#include <linux/of_platform.h>
-#include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/string.h>
 #include <linux/tee_drv.h>
 #include <linux/types.h>
-#include <linux/uaccess.h>
 #include <linux/workqueue.h>
 #include "optee_private.h"
-#include "optee_smc.h"
-#include "shm_pool.h"
 
-#define DRIVER_NAME "optee"
-
-#define OPTEE_SHM_NUM_PRIV_PAGES	CONFIG_OPTEE_SHM_NUM_PRIV_PAGES
-
-static void from_msg_param_value(struct tee_param *p, u32 attr,
-				 const struct optee_msg_param *mp)
-{
-	p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT +
-		  attr - OPTEE_MSG_ATTR_TYPE_VALUE_INPUT;
-	p->u.value.a = mp->u.value.a;
-	p->u.value.b = mp->u.value.b;
-	p->u.value.c = mp->u.value.c;
-}
-
-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;
-
-	/* Check that the memref is covered by the shm object */
-	if (p->u.memref.size) {
-		size_t o = p->u.memref.shm_offs +
-			   p->u.memref.size - 1;
-
-		rc = tee_shm_get_pa(shm, o, NULL);
-		if (rc)
-			return rc;
-	}
-
-	return 0;
-}
-
-static void from_msg_param_reg_mem(struct tee_param *p, u32 attr,
-				   const struct optee_msg_param *mp)
+int optee_pool_op_alloc_helper(struct tee_shm_pool_mgr *poolm,
+			       struct tee_shm *shm, size_t size,
+			       int (*shm_register)(struct tee_context *ctx,
+						   struct tee_shm *shm,
+						   struct page **pages,
+						   size_t num_pages,
+						   unsigned long start))
 {
-	struct tee_shm *shm;
+	unsigned int order = get_order(size);
+	struct page *page;
+	int rc = 0;
 
-	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;
+	page = alloc_pages(GFP_KERNEL | __GFP_ZERO, order);
+	if (!page)
+		return -ENOMEM;
 
-	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;
+	shm->kaddr = page_address(page);
+	shm->paddr = page_to_phys(page);
+	shm->size = PAGE_SIZE << order;
 
-		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:
-			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;
+	if (shm_register) {
+		unsigned int nr_pages = 1 << order, i;
+		struct page **pages;
 
-		default:
-			return -EINVAL;
+		pages = kcalloc(nr_pages, sizeof(*pages), GFP_KERNEL);
+		if (!pages) {
+			rc = -ENOMEM;
+			goto err;
 		}
-	}
-	return 0;
-}
-
-static void to_msg_param_value(struct optee_msg_param *mp,
-			       const struct tee_param *p)
-{
-	mp->attr = OPTEE_MSG_ATTR_TYPE_VALUE_INPUT + p->attr -
-		   TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT;
-	mp->u.value.a = p->u.value.a;
-	mp->u.value.b = p->u.value.b;
-	mp->u.value.c = p->u.value.c;
-}
-
-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;
+		for (i = 0; i < nr_pages; i++) {
+			pages[i] = page;
+			page++;
+		}
 
-	if (!p->u.memref.shm) {
-		mp->u.tmem.buf_ptr = 0;
-		return 0;
+		shm->flags |= TEE_SHM_REGISTER;
+		rc = shm_register(shm->ctx, shm, pages, nr_pages,
+				  (unsigned long)shm->kaddr);
+		kfree(pages);
+		if (rc)
+			goto err;
 	}
 
-	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:
-			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_registered(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;
-}
 
-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->sec_caps & OPTEE_SMC_SEC_CAP_DYNAMIC_SHM)
-		v.gen_caps |= TEE_GEN_CAP_REG_MEM;
-	if (optee->sec_caps & OPTEE_SMC_SEC_CAP_MEMREF_NULL)
-		v.gen_caps |= TEE_GEN_CAP_MEMREF_NULL;
-	*vers = v;
+err:
+	__free_pages(page, order);
+	return rc;
 }
 
 static void optee_bus_scan(struct work_struct *work)
@@ -262,7 +73,7 @@ static void optee_bus_scan(struct work_struct *work)
 	WARN_ON(optee_enumerate_devices(PTA_CMD_GET_DEVICES_SUPP));
 }
 
-static int optee_open(struct tee_context *ctx)
+int optee_open(struct tee_context *ctx, bool cap_memref_null)
 {
 	struct optee_context_data *ctxdata;
 	struct tee_device *teedev = ctx->teedev;
@@ -300,11 +111,7 @@ static int optee_open(struct tee_context *ctx)
 	mutex_init(&ctxdata->mutex);
 	INIT_LIST_HEAD(&ctxdata->sess_list);
 
-	if (optee->sec_caps & OPTEE_SMC_SEC_CAP_MEMREF_NULL)
-		ctx->cap_memref_null  = true;
-	else
-		ctx->cap_memref_null = false;
-
+	ctx->cap_memref_null = cap_memref_null;
 	ctx->data = ctxdata;
 	return 0;
 }
@@ -330,12 +137,12 @@ static void optee_release_helper(struct tee_context *ctx,
 	ctx->data = NULL;
 }
 
-static void optee_release(struct tee_context *ctx)
+void optee_release(struct tee_context *ctx)
 {
 	optee_release_helper(ctx, optee_close_session_helper);
 }
 
-static void optee_release_supp(struct tee_context *ctx)
+void optee_release_supp(struct tee_context *ctx)
 {
 	struct optee *optee = tee_get_drvdata(ctx->teedev);
 
@@ -347,288 +154,12 @@ static void optee_release_supp(struct tee_context *ctx)
 	optee_supp_release(&optee->supp);
 }
 
-static const struct tee_driver_ops optee_clnt_ops = {
-	.get_version = optee_get_version,
-	.open = optee_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_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_do_call_with_arg,
-	.to_msg_param = optee_to_msg_param,
-	.from_msg_param = optee_from_msg_param,
-};
-
-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)
-{
-	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 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;
-	return true;
-}
-
-static struct tee_shm_pool *optee_config_dyn_shm(void)
-{
-	struct tee_shm_pool_mgr *priv_mgr;
-	struct tee_shm_pool_mgr *dmabuf_mgr;
-	void *rc;
-
-	rc = optee_shm_pool_alloc_pages();
-	if (IS_ERR(rc))
-		return rc;
-	priv_mgr = rc;
-
-	rc = optee_shm_pool_alloc_pages();
-	if (IS_ERR(rc)) {
-		tee_shm_pool_mgr_destroy(priv_mgr);
-		return rc;
-	}
-	dmabuf_mgr = rc;
-
-	rc = tee_shm_pool_alloc(priv_mgr, dmabuf_mgr);
-	if (IS_ERR(rc)) {
-		tee_shm_pool_mgr_destroy(priv_mgr);
-		tee_shm_pool_mgr_destroy(dmabuf_mgr);
-	}
-
-	return rc;
-}
-
-static struct tee_shm_pool *
-optee_config_shm_memremap(optee_invoke_fn *invoke_fn, void **memremaped_shm)
+void optee_remove_common(struct optee *optee)
 {
-	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;
-	struct tee_shm_pool_mgr *priv_mgr;
-	struct tee_shm_pool_mgr *dmabuf_mgr;
-	void *rc;
-	const int sz = OPTEE_SHM_NUM_PRIV_PAGES * PAGE_SIZE;
-
-	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;
-
-	if (size < 2 * OPTEE_SHM_NUM_PRIV_PAGES * PAGE_SIZE) {
-		pr_err("too small shared memory area\n");
-		return ERR_PTR(-EINVAL);
-	}
-
-	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_mgr_alloc_res_mem(vaddr, paddr, sz,
-					    3 /* 8 bytes aligned */);
-	if (IS_ERR(rc))
-		goto err_memunmap;
-	priv_mgr = rc;
-
-	vaddr += sz;
-	paddr += sz;
-	size -= sz;
-
-	rc = tee_shm_pool_mgr_alloc_res_mem(vaddr, paddr, size, PAGE_SHIFT);
-	if (IS_ERR(rc))
-		goto err_free_priv_mgr;
-	dmabuf_mgr = rc;
-
-	rc = tee_shm_pool_alloc(priv_mgr, dmabuf_mgr);
-	if (IS_ERR(rc))
-		goto err_free_dmabuf_mgr;
-
-	*memremaped_shm = va;
-
-	return rc;
-
-err_free_dmabuf_mgr:
-	tee_shm_pool_mgr_destroy(dmabuf_mgr);
-err_free_priv_mgr:
-	tee_shm_pool_mgr_destroy(priv_mgr);
-err_memunmap:
-	memunmap(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_remove(struct platform_device *pdev)
-{
-	struct optee *optee = platform_get_drvdata(pdev);
-
 	/* Unregister OP-TEE specific client devices on TEE bus */
 	optee_unregister_devices();
 
 	/*
-	 * 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.
-	 */
-	optee_disable_shm_cache(optee);
-
-	/*
 	 * The two devices have to be unregistered before we can free the
 	 * other resources.
 	 */
@@ -636,39 +167,13 @@ static int optee_remove(struct platform_device *pdev)
 	tee_device_unregister(optee->teedev);
 
 	tee_shm_pool_free(optee->pool);
-	if (optee->memremaped_shm)
-		memunmap(optee->memremaped_shm);
 	optee_wait_queue_exit(&optee->wait_queue);
 	optee_supp_uninit(&optee->supp);
 	mutex_destroy(&optee->call_queue.mutex);
-
-	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)
-{
-	optee_disable_shm_cache(platform_get_drvdata(pdev));
 }
 
-static int optee_probe(struct platform_device *pdev)
+static int optee_core_init(void)
 {
-	optee_invoke_fn *invoke_fn;
-	struct tee_shm_pool *pool = ERR_PTR(-EINVAL);
-	struct optee *optee = NULL;
-	void *memremaped_shm = NULL;
-	struct tee_device *teedev;
-	u32 sec_caps;
-	int rc;
-
 	/*
 	 * The kernel may have crashed at the same time that all available
 	 * secure world threads were suspended and we cannot reschedule the
@@ -679,139 +184,15 @@ static int optee_probe(struct platform_device *pdev)
 	if (is_kdump_kernel())
 		return -ENODEV;
 
-	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)) {
-		pr_warn("capabilities mismatch\n");
-		return -EINVAL;
-	}
-
-	/*
-	 * Try to use dynamic shared memory if possible
-	 */
-	if (sec_caps & OPTEE_SMC_SEC_CAP_DYNAMIC_SHM)
-		pool = optee_config_dyn_shm();
-
-	/*
-	 * 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))
-		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;
-	}
-
-	optee->ops = &optee_ops;
-	optee->invoke_fn = invoke_fn;
-	optee->sec_caps = sec_caps;
-
-	teedev = tee_device_alloc(&optee_clnt_desc, NULL, pool, optee);
-	if (IS_ERR(teedev)) {
-		rc = PTR_ERR(teedev);
-		goto err;
-	}
-	optee->teedev = teedev;
-
-	teedev = tee_device_alloc(&optee_supp_desc, NULL, pool, optee);
-	if (IS_ERR(teedev)) {
-		rc = PTR_ERR(teedev);
-		goto err;
-	}
-	optee->supp_teedev = teedev;
-
-	rc = tee_device_register(optee->teedev);
-	if (rc)
-		goto err;
-
-	rc = tee_device_register(optee->supp_teedev);
-	if (rc)
-		goto err;
-
-	mutex_init(&optee->call_queue.mutex);
-	INIT_LIST_HEAD(&optee->call_queue.waiters);
-	optee_wait_queue_init(&optee->wait_queue);
-	optee_supp_init(&optee->supp);
-	optee->memremaped_shm = memremaped_shm;
-	optee->pool = pool;
-
-	/*
-	 * 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);
-
-	optee_enable_shm_cache(optee);
-
-	if (optee->sec_caps & OPTEE_SMC_SEC_CAP_DYNAMIC_SHM)
-		pr_info("dynamic shared memory is enabled\n");
-
-	platform_set_drvdata(pdev, optee);
-
-	rc = optee_enumerate_devices(PTA_CMD_GET_DEVICES);
-	if (rc) {
-		optee_remove(pdev);
-		return rc;
-	}
-
-	pr_info("initialized driver\n");
-	return 0;
-err:
-	if (optee) {
-		/*
-		 * tee_device_unregister() is safe to call even if the
-		 * devices hasn't been registered with
-		 * tee_device_register() yet.
-		 */
-		tee_device_unregister(optee->supp_teedev);
-		tee_device_unregister(optee->teedev);
-		kfree(optee);
-	}
-	if (pool)
-		tee_shm_pool_free(pool);
-	if (memremaped_shm)
-		memunmap(memremaped_shm);
-	return rc;
+	return optee_smc_abi_register();
 }
+module_init(optee_core_init);
 
-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_remove,
-	.shutdown = optee_shutdown,
-	.driver = {
-		.name = "optee",
-		.of_match_table = optee_dt_match,
-	},
-};
-module_platform_driver(optee_driver);
+static void optee_core_exit(void)
+{
+	optee_smc_abi_unregister();
+}
+module_exit(optee_core_exit);
 
 MODULE_AUTHOR("Linaro");
 MODULE_DESCRIPTION("OP-TEE driver");