Commit 967c9cca authored by Jens Wiklander's avatar Jens Wiklander

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: default avatarAndreas 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: default avatarScott Branden <scott.branden@broadcom.com>
Reviewed-by: default avatarJavier González <javier@javigon.com>
Signed-off-by: default avatarJens Wiklander <jens.wiklander@linaro.org>
parent c8bfafb1
......@@ -308,6 +308,7 @@ Code Seq#(hex) Include File Comments
0xA3 80-8F Port ACL in development:
<mailto:tlewis@mindspring.com>
0xA3 90-9F linux/dtlk.h
0xA4 00-1F uapi/linux/tee.h Generic TEE subsystem
0xAA 00-3F linux/uapi/linux/userfaultfd.h
0xAB 00-1F linux/nbd.h
0xAC 00-1F linux/raw.h
......
......@@ -11086,6 +11086,13 @@ F: drivers/hwtracing/stm/
F: include/linux/stm.h
F: include/uapi/linux/stm.h
TEE SUBSYSTEM
M: Jens Wiklander <jens.wiklander@linaro.org>
S: Maintained
F: include/linux/tee_drv.h
F: include/uapi/linux/tee.h
F: drivers/tee/
THUNDERBOLT DRIVER
M: Andreas Noever <andreas.noever@gmail.com>
S: Maintained
......
......@@ -204,4 +204,6 @@ source "drivers/fpga/Kconfig"
source "drivers/fsi/Kconfig"
source "drivers/tee/Kconfig"
endmenu
......@@ -177,3 +177,4 @@ obj-$(CONFIG_ANDROID) += android/
obj-$(CONFIG_NVMEM) += nvmem/
obj-$(CONFIG_FPGA) += fpga/
obj-$(CONFIG_FSI) += fsi/
obj-$(CONFIG_TEE) += tee/
# Generic Trusted Execution Environment Configuration
config TEE
tristate "Trusted Execution Environment support"
select DMA_SHARED_BUFFER
select GENERIC_ALLOCATOR
help
This implements a generic interface towards a Trusted Execution
Environment (TEE).
obj-$(CONFIG_TEE) += tee.o
tee-objs += tee_core.o
tee-objs += tee_shm.o
tee-objs += tee_shm_pool.o
This diff is collapsed.
/*
* Copyright (c) 2015-2016, 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.
*
*/
#ifndef TEE_PRIVATE_H
#define TEE_PRIVATE_H
#include <linux/cdev.h>
#include <linux/completion.h>
#include <linux/device.h>
#include <linux/kref.h>
#include <linux/mutex.h>
#include <linux/types.h>
struct tee_device;
/**
* struct tee_shm - shared memory object
* @teedev: device used to allocate the object
* @ctx: context using the object, if NULL the context is gone
* @link link element
* @paddr: physical address of the shared memory
* @kaddr: virtual address of the shared memory
* @size: size of shared memory
* @dmabuf: dmabuf used to for exporting to user space
* @flags: defined by TEE_SHM_* in tee_drv.h
* @id: unique id of a shared memory object on this device
*/
struct tee_shm {
struct tee_device *teedev;
struct tee_context *ctx;
struct list_head link;
phys_addr_t paddr;
void *kaddr;
size_t size;
struct dma_buf *dmabuf;
u32 flags;
int id;
};
struct tee_shm_pool_mgr;
/**
* struct tee_shm_pool_mgr_ops - shared memory pool manager operations
* @alloc: called when allocating shared memory
* @free: called when freeing shared memory
*/
struct tee_shm_pool_mgr_ops {
int (*alloc)(struct tee_shm_pool_mgr *poolmgr, struct tee_shm *shm,
size_t size);
void (*free)(struct tee_shm_pool_mgr *poolmgr, struct tee_shm *shm);
};
/**
* struct tee_shm_pool_mgr - shared memory manager
* @ops: operations
* @private_data: private data for the shared memory manager
*/
struct tee_shm_pool_mgr {
const struct tee_shm_pool_mgr_ops *ops;
void *private_data;
};
/**
* struct tee_shm_pool - shared memory pool
* @private_mgr: pool manager for shared memory only between kernel
* and secure world
* @dma_buf_mgr: pool manager for shared memory exported to user space
* @destroy: called when destroying the pool
* @private_data: private data for the pool
*/
struct tee_shm_pool {
struct tee_shm_pool_mgr private_mgr;
struct tee_shm_pool_mgr dma_buf_mgr;
void (*destroy)(struct tee_shm_pool *pool);
void *private_data;
};
#define TEE_DEVICE_FLAG_REGISTERED 0x1
#define TEE_MAX_DEV_NAME_LEN 32
/**
* struct tee_device - TEE Device representation
* @name: name of device
* @desc: description of device
* @id: unique id of device
* @flags: represented by TEE_DEVICE_FLAG_REGISTERED above
* @dev: embedded basic device structure
* @cdev: embedded cdev
* @num_users: number of active users of this device
* @c_no_user: completion used when unregistering the device
* @mutex: mutex protecting @num_users and @idr
* @idr: register of shared memory object allocated on this device
* @pool: shared memory pool
*/
struct tee_device {
char name[TEE_MAX_DEV_NAME_LEN];
const struct tee_desc *desc;
int id;
unsigned int flags;
struct device dev;
struct cdev cdev;
size_t num_users;
struct completion c_no_users;
struct mutex mutex; /* protects num_users and idr */
struct idr idr;
struct tee_shm_pool *pool;
};
int tee_shm_init(void);
int tee_shm_get_fd(struct tee_shm *shm);
bool tee_device_get(struct tee_device *teedev);
void tee_device_put(struct tee_device *teedev);
#endif /*TEE_PRIVATE_H*/
/*
* Copyright (c) 2015-2016, 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/fdtable.h>
#include <linux/idr.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/tee_drv.h>
#include "tee_private.h"
static void tee_shm_release(struct tee_shm *shm)
{
struct tee_device *teedev = shm->teedev;
struct tee_shm_pool_mgr *poolm;
mutex_lock(&teedev->mutex);
idr_remove(&teedev->idr, shm->id);
if (shm->ctx)
list_del(&shm->link);
mutex_unlock(&teedev->mutex);
if (shm->flags & TEE_SHM_DMA_BUF)
poolm = &teedev->pool->dma_buf_mgr;
else
poolm = &teedev->pool->private_mgr;
poolm->ops->free(poolm, shm);
kfree(shm);
tee_device_put(teedev);
}
static struct sg_table *tee_shm_op_map_dma_buf(struct dma_buf_attachment
*attach, enum dma_data_direction dir)
{
return NULL;
}
static void tee_shm_op_unmap_dma_buf(struct dma_buf_attachment *attach,
struct sg_table *table,
enum dma_data_direction dir)
{
}
static void tee_shm_op_release(struct dma_buf *dmabuf)
{
struct tee_shm *shm = dmabuf->priv;
tee_shm_release(shm);
}
static void *tee_shm_op_kmap_atomic(struct dma_buf *dmabuf, unsigned long pgnum)
{
return NULL;
}
static void *tee_shm_op_kmap(struct dma_buf *dmabuf, unsigned long pgnum)
{
return NULL;
}
static int tee_shm_op_mmap(struct dma_buf *dmabuf, struct vm_area_struct *vma)
{
struct tee_shm *shm = dmabuf->priv;
size_t size = vma->vm_end - vma->vm_start;
return remap_pfn_range(vma, vma->vm_start, shm->paddr >> PAGE_SHIFT,
size, vma->vm_page_prot);
}
static struct dma_buf_ops tee_shm_dma_buf_ops = {
.map_dma_buf = tee_shm_op_map_dma_buf,
.unmap_dma_buf = tee_shm_op_unmap_dma_buf,
.release = tee_shm_op_release,
.kmap_atomic = tee_shm_op_kmap_atomic,
.kmap = tee_shm_op_kmap,
.mmap = tee_shm_op_mmap,
};
/**
* tee_shm_alloc() - Allocate shared memory
* @ctx: Context that allocates the shared memory
* @size: Requested size of shared memory
* @flags: Flags setting properties for the requested shared memory.
*
* Memory allocated as global shared memory is automatically freed when the
* TEE file pointer is closed. The @flags field uses the bits defined by
* TEE_SHM_* in <linux/tee_drv.h>. TEE_SHM_MAPPED must currently always be
* set. If TEE_SHM_DMA_BUF global shared memory will be allocated and
* associated with a dma-buf handle, else driver private memory.
*/
struct tee_shm *tee_shm_alloc(struct tee_context *ctx, size_t size, u32 flags)
{
struct tee_device *teedev = ctx->teedev;
struct tee_shm_pool_mgr *poolm = NULL;
struct tee_shm *shm;
void *ret;
int rc;
if (!(flags & TEE_SHM_MAPPED)) {
dev_err(teedev->dev.parent,
"only mapped allocations supported\n");
return ERR_PTR(-EINVAL);
}
if ((flags & ~(TEE_SHM_MAPPED | TEE_SHM_DMA_BUF))) {
dev_err(teedev->dev.parent, "invalid shm flags 0x%x", flags);
return ERR_PTR(-EINVAL);
}
if (!tee_device_get(teedev))
return ERR_PTR(-EINVAL);
if (!teedev->pool) {
/* teedev has been detached from driver */
ret = ERR_PTR(-EINVAL);
goto err_dev_put;
}
shm = kzalloc(sizeof(*shm), GFP_KERNEL);
if (!shm) {
ret = ERR_PTR(-ENOMEM);
goto err_dev_put;
}
shm->flags = flags;
shm->teedev = teedev;
shm->ctx = ctx;
if (flags & TEE_SHM_DMA_BUF)
poolm = &teedev->pool->dma_buf_mgr;
else
poolm = &teedev->pool->private_mgr;
rc = poolm->ops->alloc(poolm, shm, size);
if (rc) {
ret = ERR_PTR(rc);
goto err_kfree;
}
mutex_lock(&teedev->mutex);
shm->id = idr_alloc(&teedev->idr, shm, 1, 0, GFP_KERNEL);
mutex_unlock(&teedev->mutex);
if (shm->id < 0) {
ret = ERR_PTR(shm->id);
goto err_pool_free;
}
if (flags & TEE_SHM_DMA_BUF) {
DEFINE_DMA_BUF_EXPORT_INFO(exp_info);
exp_info.ops = &tee_shm_dma_buf_ops;
exp_info.size = shm->size;
exp_info.flags = O_RDWR;
exp_info.priv = shm;
shm->dmabuf = dma_buf_export(&exp_info);
if (IS_ERR(shm->dmabuf)) {
ret = ERR_CAST(shm->dmabuf);
goto err_rem;
}
}
mutex_lock(&teedev->mutex);
list_add_tail(&shm->link, &ctx->list_shm);
mutex_unlock(&teedev->mutex);
return shm;
err_rem:
mutex_lock(&teedev->mutex);
idr_remove(&teedev->idr, shm->id);
mutex_unlock(&teedev->mutex);
err_pool_free:
poolm->ops->free(poolm, shm);
err_kfree:
kfree(shm);
err_dev_put:
tee_device_put(teedev);
return ret;
}
EXPORT_SYMBOL_GPL(tee_shm_alloc);
/**
* tee_shm_get_fd() - Increase reference count and return file descriptor
* @shm: Shared memory handle
* @returns user space file descriptor to shared memory
*/
int tee_shm_get_fd(struct tee_shm *shm)
{
u32 req_flags = TEE_SHM_MAPPED | TEE_SHM_DMA_BUF;
int fd;
if ((shm->flags & req_flags) != req_flags)
return -EINVAL;
fd = dma_buf_fd(shm->dmabuf, O_CLOEXEC);
if (fd >= 0)
get_dma_buf(shm->dmabuf);
return fd;
}
/**
* tee_shm_free() - Free shared memory
* @shm: Handle to shared memory to free
*/
void tee_shm_free(struct tee_shm *shm)
{
/*
* dma_buf_put() decreases the dmabuf reference counter and will
* call tee_shm_release() when the last reference is gone.
*
* In the case of driver private memory we call tee_shm_release
* directly instead as it doesn't have a reference counter.
*/
if (shm->flags & TEE_SHM_DMA_BUF)
dma_buf_put(shm->dmabuf);
else
tee_shm_release(shm);
}
EXPORT_SYMBOL_GPL(tee_shm_free);
/**
* tee_shm_va2pa() - Get physical address of a virtual address
* @shm: Shared memory handle
* @va: Virtual address to tranlsate
* @pa: Returned physical address
* @returns 0 on success and < 0 on failure
*/
int tee_shm_va2pa(struct tee_shm *shm, void *va, phys_addr_t *pa)
{
/* Check that we're in the range of the shm */
if ((char *)va < (char *)shm->kaddr)
return -EINVAL;
if ((char *)va >= ((char *)shm->kaddr + shm->size))
return -EINVAL;
return tee_shm_get_pa(
shm, (unsigned long)va - (unsigned long)shm->kaddr, pa);
}
EXPORT_SYMBOL_GPL(tee_shm_va2pa);
/**
* tee_shm_pa2va() - Get virtual address of a physical address
* @shm: Shared memory handle
* @pa: Physical address to tranlsate
* @va: Returned virtual address
* @returns 0 on success and < 0 on failure
*/
int tee_shm_pa2va(struct tee_shm *shm, phys_addr_t pa, void **va)
{
/* Check that we're in the range of the shm */
if (pa < shm->paddr)
return -EINVAL;
if (pa >= (shm->paddr + shm->size))
return -EINVAL;
if (va) {
void *v = tee_shm_get_va(shm, pa - shm->paddr);
if (IS_ERR(v))
return PTR_ERR(v);
*va = v;
}
return 0;
}
EXPORT_SYMBOL_GPL(tee_shm_pa2va);
/**
* tee_shm_get_va() - Get virtual address of a shared memory plus an offset
* @shm: Shared memory handle
* @offs: Offset from start of this shared memory
* @returns virtual address of the shared memory + offs if offs is within
* the bounds of this shared memory, else an ERR_PTR
*/
void *tee_shm_get_va(struct tee_shm *shm, size_t offs)
{
if (offs >= shm->size)
return ERR_PTR(-EINVAL);
return (char *)shm->kaddr + offs;
}
EXPORT_SYMBOL_GPL(tee_shm_get_va);
/**
* tee_shm_get_pa() - Get physical address of a shared memory plus an offset
* @shm: Shared memory handle
* @offs: Offset from start of this shared memory
* @pa: Physical address to return
* @returns 0 if offs is within the bounds of this shared memory, else an
* error code.
*/
int tee_shm_get_pa(struct tee_shm *shm, size_t offs, phys_addr_t *pa)
{
if (offs >= shm->size)
return -EINVAL;
if (pa)
*pa = shm->paddr + offs;
return 0;
}
EXPORT_SYMBOL_GPL(tee_shm_get_pa);
/**
* tee_shm_get_from_id() - Find shared memory object and increase reference
* count
* @ctx: Context owning the shared memory
* @id: Id of shared memory object
* @returns a pointer to 'struct tee_shm' on success or an ERR_PTR on failure
*/
struct tee_shm *tee_shm_get_from_id(struct tee_context *ctx, int id)
{
struct tee_device *teedev;
struct tee_shm *shm;
if (!ctx)
return ERR_PTR(-EINVAL);
teedev = ctx->teedev;
mutex_lock(&teedev->mutex);
shm = idr_find(&teedev->idr, id);
if (!shm || shm->ctx != ctx)
shm = ERR_PTR(-EINVAL);
else if (shm->flags & TEE_SHM_DMA_BUF)
get_dma_buf(shm->dmabuf);
mutex_unlock(&teedev->mutex);
return shm;
}
EXPORT_SYMBOL_GPL(tee_shm_get_from_id);
/**
* tee_shm_get_id() - Get id of a shared memory object
* @shm: Shared memory handle
* @returns id
*/
int tee_shm_get_id(struct tee_shm *shm)
{
return shm->id;
}
EXPORT_SYMBOL_GPL(tee_shm_get_id);
/**
* tee_shm_put() - Decrease reference count on a shared memory handle
* @shm: Shared memory handle
*/
void tee_shm_put(struct tee_shm *shm)
{
if (shm->flags & TEE_SHM_DMA_BUF)
dma_buf_put(shm->dmabuf);
}
EXPORT_SYMBOL_GPL(tee_shm_put);
/*
* 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);
/*
* Copyright (c) 2015-2016, 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.
*
*/
#ifndef __TEE_DRV_H
#define __TEE_DRV_H
#include <linux/types.h>
#include <linux/idr.h>
#include <linux/list.h>
#include <linux/tee.h>
/*
* The file describes the API provided by the generic TEE driver to the
* specific TEE driver.
*/
#define TEE_SHM_MAPPED 0x1 /* Memory mapped by the kernel */
#define TEE_SHM_DMA_BUF 0x2 /* Memory with dma-buf handle */
struct tee_device;
struct tee_shm;
struct tee_shm_pool;