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|
/*
* Copyright (c) 2015, Linaro Limited
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#include <linux/arm-smccc.h>
#include <linux/device.h>
#include <linux/err.h>
#include <linux/errno.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/tee_drv.h>
#include <linux/types.h>
#include <linux/uaccess.h>
#include "optee_private.h"
#include "optee_smc.h"
struct optee_call_waiter {
struct list_head list_node;
struct completion c;
};
static void optee_cq_wait_init(struct optee_call_queue *cq,
struct optee_call_waiter *w)
{
/*
* We're preparing to make a call to secure world. In case we can't
* allocate a thread in secure world we'll end up waiting in
* optee_cq_wait_for_completion().
*
* Normally if there's no contention in secure world the call will
* complete and we can cleanup directly with optee_cq_wait_final().
*/
mutex_lock(&cq->mutex);
/*
* We add ourselves to the queue, but we don't wait. This
* guarantees that we don't lose a completion if secure world
* returns busy and another thread just exited and try to complete
* someone.
*/
init_completion(&w->c);
list_add_tail(&w->list_node, &cq->waiters);
mutex_unlock(&cq->mutex);
}
static void optee_cq_wait_for_completion(struct optee_call_queue *cq,
struct optee_call_waiter *w)
{
wait_for_completion(&w->c);
mutex_lock(&cq->mutex);
/* Move to end of list to get out of the way for other waiters */
list_del(&w->list_node);
reinit_completion(&w->c);
list_add_tail(&w->list_node, &cq->waiters);
mutex_unlock(&cq->mutex);
}
static void optee_cq_complete_one(struct optee_call_queue *cq)
{
struct optee_call_waiter *w;
list_for_each_entry(w, &cq->waiters, list_node) {
if (!completion_done(&w->c)) {
complete(&w->c);
break;
}
}
}
static void optee_cq_wait_final(struct optee_call_queue *cq,
struct optee_call_waiter *w)
{
/*
* We're done with the call to secure world. The thread in secure
* world that was used for this call is now available for some
* other task to use.
*/
mutex_lock(&cq->mutex);
/* Get out of the list */
list_del(&w->list_node);
/* Wake up one eventual waiting task */
optee_cq_complete_one(cq);
/*
* If we're completed we've got a completion from another task that
* was just done with its call to secure world. Since yet another
* thread now is available in secure world wake up another eventual
* waiting task.
*/
if (completion_done(&w->c))
optee_cq_complete_one(cq);
mutex_unlock(&cq->mutex);
}
/* Requires the filpstate mutex to be held */
static struct optee_session *find_session(struct optee_context_data *ctxdata,
u32 session_id)
{
struct optee_session *sess;
list_for_each_entry(sess, &ctxdata->sess_list, list_node)
if (sess->session_id == session_id)
return sess;
return NULL;
}
/**
* optee_do_call_with_arg() - Do an SMC to OP-TEE in secure world
* @ctx: calling context
* @parg: physical address of message to pass to secure world
*
* 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
*/
u32 optee_do_call_with_arg(struct tee_context *ctx, phys_addr_t parg)
{
struct optee *optee = tee_get_drvdata(ctx->teedev);
struct optee_call_waiter w;
struct optee_rpc_param param = { };
struct optee_call_ctx call_ctx = { };
u32 ret;
param.a0 = OPTEE_SMC_CALL_WITH_ARG;
reg_pair_from_64(¶m.a1, ¶m.a2, parg);
/* Initialize waiter */
optee_cq_wait_init(&optee->call_queue, &w);
while (true) {
struct arm_smccc_res res;
optee->invoke_fn(param.a0, param.a1, param.a2, param.a3,
param.a4, param.a5, param.a6, param.a7,
&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)) {
param.a0 = res.a0;
param.a1 = res.a1;
param.a2 = res.a2;
param.a3 = res.a3;
optee_handle_rpc(ctx, ¶m, &call_ctx);
} else {
ret = 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 ret;
}
static struct tee_shm *get_msg_arg(struct tee_context *ctx, size_t num_params,
struct optee_msg_arg **msg_arg,
phys_addr_t *msg_parg)
{
int rc;
struct tee_shm *shm;
struct optee_msg_arg *ma;
shm = tee_shm_alloc(ctx, OPTEE_MSG_GET_ARG_SIZE(num_params),
TEE_SHM_MAPPED);
if (IS_ERR(shm))
return shm;
ma = tee_shm_get_va(shm, 0);
if (IS_ERR(ma)) {
rc = PTR_ERR(ma);
goto out;
}
rc = tee_shm_get_pa(shm, 0, msg_parg);
if (rc)
goto out;
memset(ma, 0, OPTEE_MSG_GET_ARG_SIZE(num_params));
ma->num_params = num_params;
*msg_arg = ma;
out:
if (rc) {
tee_shm_free(shm);
return ERR_PTR(rc);
}
return shm;
}
int optee_open_session(struct tee_context *ctx,
struct tee_ioctl_open_session_arg *arg,
struct tee_param *param)
{
struct optee_context_data *ctxdata = ctx->data;
int rc;
struct tee_shm *shm;
struct optee_msg_arg *msg_arg;
phys_addr_t msg_parg;
struct optee_session *sess = NULL;
/* +2 for the meta parameters added below */
shm = get_msg_arg(ctx, arg->num_params + 2, &msg_arg, &msg_parg);
if (IS_ERR(shm))
return PTR_ERR(shm);
msg_arg->cmd = OPTEE_MSG_CMD_OPEN_SESSION;
msg_arg->cancel_id = arg->cancel_id;
/*
* Initialize and add the meta parameters needed when opening a
* session.
*/
msg_arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_VALUE_INPUT |
OPTEE_MSG_ATTR_META;
msg_arg->params[1].attr = OPTEE_MSG_ATTR_TYPE_VALUE_INPUT |
OPTEE_MSG_ATTR_META;
memcpy(&msg_arg->params[0].u.value, arg->uuid, sizeof(arg->uuid));
memcpy(&msg_arg->params[1].u.value, arg->uuid, sizeof(arg->clnt_uuid));
msg_arg->params[1].u.value.c = arg->clnt_login;
rc = optee_to_msg_param(msg_arg->params + 2, arg->num_params, param);
if (rc)
goto out;
sess = kzalloc(sizeof(*sess), GFP_KERNEL);
if (!sess) {
rc = -ENOMEM;
goto out;
}
if (optee_do_call_with_arg(ctx, msg_parg)) {
msg_arg->ret = TEEC_ERROR_COMMUNICATION;
msg_arg->ret_origin = TEEC_ORIGIN_COMMS;
}
if (msg_arg->ret == TEEC_SUCCESS) {
/* A new session has been created, add it to the list. */
sess->session_id = msg_arg->session;
mutex_lock(&ctxdata->mutex);
list_add(&sess->list_node, &ctxdata->sess_list);
mutex_unlock(&ctxdata->mutex);
} else {
kfree(sess);
}
if (optee_from_msg_param(param, arg->num_params, msg_arg->params + 2)) {
arg->ret = TEEC_ERROR_COMMUNICATION;
arg->ret_origin = TEEC_ORIGIN_COMMS;
/* Close session again to avoid leakage */
optee_close_session(ctx, msg_arg->session);
} else {
arg->session = msg_arg->session;
arg->ret = msg_arg->ret;
arg->ret_origin = msg_arg->ret_origin;
}
out:
tee_shm_free(shm);
return rc;
}
int optee_close_session(struct tee_context *ctx, u32 session)
{
struct optee_context_data *ctxdata = ctx->data;
struct tee_shm *shm;
struct optee_msg_arg *msg_arg;
phys_addr_t msg_parg;
struct optee_session *sess;
/* Check that the session is valid and remove it from the list */
mutex_lock(&ctxdata->mutex);
sess = find_session(ctxdata, session);
if (sess)
list_del(&sess->list_node);
mutex_unlock(&ctxdata->mutex);
if (!sess)
return -EINVAL;
kfree(sess);
shm = get_msg_arg(ctx, 0, &msg_arg, &msg_parg);
if (IS_ERR(shm))
return PTR_ERR(shm);
msg_arg->cmd = OPTEE_MSG_CMD_CLOSE_SESSION;
msg_arg->session = session;
optee_do_call_with_arg(ctx, msg_parg);
tee_shm_free(shm);
return 0;
}
int optee_invoke_func(struct tee_context *ctx, struct tee_ioctl_invoke_arg *arg,
struct tee_param *param)
{
struct optee_context_data *ctxdata = ctx->data;
struct tee_shm *shm;
struct optee_msg_arg *msg_arg;
phys_addr_t msg_parg;
struct optee_session *sess;
int rc;
/* Check that the session is valid */
mutex_lock(&ctxdata->mutex);
sess = find_session(ctxdata, arg->session);
mutex_unlock(&ctxdata->mutex);
if (!sess)
return -EINVAL;
shm = get_msg_arg(ctx, arg->num_params, &msg_arg, &msg_parg);
if (IS_ERR(shm))
return PTR_ERR(shm);
msg_arg->cmd = OPTEE_MSG_CMD_INVOKE_COMMAND;
msg_arg->func = arg->func;
msg_arg->session = arg->session;
msg_arg->cancel_id = arg->cancel_id;
rc = optee_to_msg_param(msg_arg->params, arg->num_params, param);
if (rc)
goto out;
if (optee_do_call_with_arg(ctx, msg_parg)) {
msg_arg->ret = TEEC_ERROR_COMMUNICATION;
msg_arg->ret_origin = TEEC_ORIGIN_COMMS;
}
if (optee_from_msg_param(param, arg->num_params, msg_arg->params)) {
msg_arg->ret = TEEC_ERROR_COMMUNICATION;
msg_arg->ret_origin = TEEC_ORIGIN_COMMS;
}
arg->ret = msg_arg->ret;
arg->ret_origin = msg_arg->ret_origin;
out:
tee_shm_free(shm);
return rc;
}
int optee_cancel_req(struct tee_context *ctx, u32 cancel_id, u32 session)
{
struct optee_context_data *ctxdata = ctx->data;
struct tee_shm *shm;
struct optee_msg_arg *msg_arg;
phys_addr_t msg_parg;
struct optee_session *sess;
/* Check that the session is valid */
mutex_lock(&ctxdata->mutex);
sess = find_session(ctxdata, session);
mutex_unlock(&ctxdata->mutex);
if (!sess)
return -EINVAL;
shm = get_msg_arg(ctx, 0, &msg_arg, &msg_parg);
if (IS_ERR(shm))
return PTR_ERR(shm);
msg_arg->cmd = OPTEE_MSG_CMD_CANCEL;
msg_arg->session = session;
msg_arg->cancel_id = cancel_id;
optee_do_call_with_arg(ctx, msg_parg);
tee_shm_free(shm);
return 0;
}
/**
* optee_enable_shm_cache() - Enables caching of some shared memory allocation
* in OP-TEE
* @optee: main service struct
*/
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->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
*/
void optee_disable_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) {
union {
struct arm_smccc_res smccc;
struct optee_smc_disable_shm_cache_result result;
} res;
optee->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;
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);
}
#define PAGELIST_ENTRIES_PER_PAGE \
((OPTEE_MSG_NONCONTIG_PAGE_SIZE / sizeof(u64)) - 1)
/**
* 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
*/
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);
}
}
}
/*
* 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;
}
u64 *optee_allocate_pages_list(size_t num_entries)
{
return alloc_pages_exact(get_pages_list_size(num_entries), GFP_KERNEL);
}
void optee_free_pages_list(void *list, size_t num_entries)
{
free_pages_exact(list, get_pages_list_size(num_entries));
}
static bool is_normal_memory(pgprot_t p)
{
#if defined(CONFIG_ARM)
return (((pgprot_val(p) & L_PTE_MT_MASK) == L_PTE_MT_WRITEALLOC) ||
((pgprot_val(p) & L_PTE_MT_MASK) == L_PTE_MT_WRITEBACK));
#elif defined(CONFIG_ARM64)
return (pgprot_val(p) & PTE_ATTRINDX_MASK) == PTE_ATTRINDX(MT_NORMAL);
#else
#error "Unuspported architecture"
#endif
}
static int __check_mem_type(struct vm_area_struct *vma, unsigned long end)
{
while (vma && is_normal_memory(vma->vm_page_prot)) {
if (vma->vm_end >= end)
return 0;
vma = vma->vm_next;
}
return -EINVAL;
}
static int check_mem_type(unsigned long start, size_t num_pages)
{
struct mm_struct *mm = current->mm;
int rc;
down_read(&mm->mmap_sem);
rc = __check_mem_type(find_vma(mm, start),
start + num_pages * PAGE_SIZE);
up_read(&mm->mmap_sem);
return rc;
}
int optee_shm_register(struct tee_context *ctx, struct tee_shm *shm,
struct page **pages, size_t num_pages,
unsigned long start)
{
struct tee_shm *shm_arg = NULL;
struct optee_msg_arg *msg_arg;
u64 *pages_list;
phys_addr_t msg_parg;
int rc;
if (!num_pages)
return -EINVAL;
rc = check_mem_type(start, num_pages);
if (rc)
return rc;
pages_list = optee_allocate_pages_list(num_pages);
if (!pages_list)
return -ENOMEM;
shm_arg = get_msg_arg(ctx, 1, &msg_arg, &msg_parg);
if (IS_ERR(shm_arg)) {
rc = PTR_ERR(shm_arg);
goto out;
}
optee_fill_pages_list(pages_list, pages, num_pages,
tee_shm_get_page_offset(shm));
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_do_call_with_arg(ctx, msg_parg) ||
msg_arg->ret != TEEC_SUCCESS)
rc = -EINVAL;
tee_shm_free(shm_arg);
out:
optee_free_pages_list(pages_list, num_pages);
return rc;
}
int optee_shm_unregister(struct tee_context *ctx, struct tee_shm *shm)
{
struct tee_shm *shm_arg;
struct optee_msg_arg *msg_arg;
phys_addr_t msg_parg;
int rc = 0;
shm_arg = get_msg_arg(ctx, 1, &msg_arg, &msg_parg);
if (IS_ERR(shm_arg))
return PTR_ERR(shm_arg);
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_do_call_with_arg(ctx, msg_parg) ||
msg_arg->ret != TEEC_SUCCESS)
rc = -EINVAL;
tee_shm_free(shm_arg);
return rc;
}
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 check_mem_type(start, num_pages);
}
int optee_shm_unregister_supp(struct tee_context *ctx, struct tee_shm *shm)
{
return 0;
}
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