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linux-next/drivers/tee/tee_shm_pool.c
Jens Wiklander 967c9cca2c tee: generic TEE subsystem
Initial patch for generic TEE subsystem.
This subsystem provides:
* Registration/un-registration of TEE drivers.
* Shared memory between normal world and secure world.
* Ioctl interface for interaction with user space.
* Sysfs implementation_id of TEE driver

A TEE (Trusted Execution Environment) driver is a driver that interfaces
with a trusted OS running in some secure environment, for example,
TrustZone on ARM cpus, or a separate secure co-processor etc.

The TEE subsystem can serve a TEE driver for a Global Platform compliant
TEE, but it's not limited to only Global Platform TEEs.

This patch builds on other similar implementations trying to solve
the same problem:
* "optee_linuxdriver" by among others
  Jean-michel DELORME<jean-michel.delorme@st.com> and
  Emmanuel MICHEL <emmanuel.michel@st.com>
* "Generic TrustZone Driver" by Javier González <javier@javigon.com>

Acked-by: Andreas Dannenberg <dannenberg@ti.com>
Tested-by: Jerome Forissier <jerome.forissier@linaro.org> (HiKey)
Tested-by: Volodymyr Babchuk <vlad.babchuk@gmail.com> (RCAR H3)
Tested-by: Scott Branden <scott.branden@broadcom.com>
Reviewed-by: Javier González <javier@javigon.com>
Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
2017-03-09 15:42:33 +01:00

157 lines
4.0 KiB
C

/*
* 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/device.h>
#include <linux/dma-buf.h>
#include <linux/genalloc.h>
#include <linux/slab.h>
#include <linux/tee_drv.h>
#include "tee_private.h"
static int pool_op_gen_alloc(struct tee_shm_pool_mgr *poolm,
struct tee_shm *shm, size_t size)
{
unsigned long va;
struct gen_pool *genpool = poolm->private_data;
size_t s = roundup(size, 1 << genpool->min_alloc_order);
va = gen_pool_alloc(genpool, s);
if (!va)
return -ENOMEM;
memset((void *)va, 0, s);
shm->kaddr = (void *)va;
shm->paddr = gen_pool_virt_to_phys(genpool, va);
shm->size = s;
return 0;
}
static void pool_op_gen_free(struct tee_shm_pool_mgr *poolm,
struct tee_shm *shm)
{
gen_pool_free(poolm->private_data, (unsigned long)shm->kaddr,
shm->size);
shm->kaddr = NULL;
}
static const struct tee_shm_pool_mgr_ops pool_ops_generic = {
.alloc = pool_op_gen_alloc,
.free = pool_op_gen_free,
};
static void pool_res_mem_destroy(struct tee_shm_pool *pool)
{
gen_pool_destroy(pool->private_mgr.private_data);
gen_pool_destroy(pool->dma_buf_mgr.private_data);
}
static int pool_res_mem_mgr_init(struct tee_shm_pool_mgr *mgr,
struct tee_shm_pool_mem_info *info,
int min_alloc_order)
{
size_t page_mask = PAGE_SIZE - 1;
struct gen_pool *genpool = NULL;
int rc;
/*
* Start and end must be page aligned
*/
if ((info->vaddr & page_mask) || (info->paddr & page_mask) ||
(info->size & page_mask))
return -EINVAL;
genpool = gen_pool_create(min_alloc_order, -1);
if (!genpool)
return -ENOMEM;
gen_pool_set_algo(genpool, gen_pool_best_fit, NULL);
rc = gen_pool_add_virt(genpool, info->vaddr, info->paddr, info->size,
-1);
if (rc) {
gen_pool_destroy(genpool);
return rc;
}
mgr->private_data = genpool;
mgr->ops = &pool_ops_generic;
return 0;
}
/**
* tee_shm_pool_alloc_res_mem() - Create a shared memory pool from reserved
* memory range
* @priv_info: Information for driver private shared memory pool
* @dmabuf_info: Information for dma-buf shared memory pool
*
* Start and end of pools will must be page aligned.
*
* Allocation with the flag TEE_SHM_DMA_BUF set will use the range supplied
* in @dmabuf, others will use the range provided by @priv.
*
* @returns pointer to a 'struct tee_shm_pool' or an ERR_PTR on failure.
*/
struct tee_shm_pool *
tee_shm_pool_alloc_res_mem(struct tee_shm_pool_mem_info *priv_info,
struct tee_shm_pool_mem_info *dmabuf_info)
{
struct tee_shm_pool *pool = NULL;
int ret;
pool = kzalloc(sizeof(*pool), GFP_KERNEL);
if (!pool) {
ret = -ENOMEM;
goto err;
}
/*
* Create the pool for driver private shared memory
*/
ret = pool_res_mem_mgr_init(&pool->private_mgr, priv_info,
3 /* 8 byte aligned */);
if (ret)
goto err;
/*
* Create the pool for dma_buf shared memory
*/
ret = pool_res_mem_mgr_init(&pool->dma_buf_mgr, dmabuf_info,
PAGE_SHIFT);
if (ret)
goto err;
pool->destroy = pool_res_mem_destroy;
return pool;
err:
if (ret == -ENOMEM)
pr_err("%s: can't allocate memory for res_mem shared memory pool\n", __func__);
if (pool && pool->private_mgr.private_data)
gen_pool_destroy(pool->private_mgr.private_data);
kfree(pool);
return ERR_PTR(ret);
}
EXPORT_SYMBOL_GPL(tee_shm_pool_alloc_res_mem);
/**
* tee_shm_pool_free() - Free a shared memory pool
* @pool: The shared memory pool to free
*
* There must be no remaining shared memory allocated from this pool when
* this function is called.
*/
void tee_shm_pool_free(struct tee_shm_pool *pool)
{
pool->destroy(pool);
kfree(pool);
}
EXPORT_SYMBOL_GPL(tee_shm_pool_free);