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author | Linus Torvalds <torvalds@linux-foundation.org> | 2017-05-10 11:20:09 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2017-05-10 11:20:09 -0700 |
commit | a2d9214c730f54ff72c2940bcd7f22d1fccb26ec (patch) | |
tree | a50a1187ebba2c345213f27b4372939a3f39987b /drivers/tee/tee_shm_pool.c | |
parent | de4d195308ad589626571dbe5789cebf9695a204 (diff) | |
parent | 414d06ace9cca3725b6c2072e1951e1e03807f63 (diff) | |
download | lwn-a2d9214c730f54ff72c2940bcd7f22d1fccb26ec.tar.gz lwn-a2d9214c730f54ff72c2940bcd7f22d1fccb26ec.zip |
Merge tag 'armsoc-tee' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc
Pull TEE driver infrastructure and OP-TEE drivers from Arnd Bergmann:
"This introduces a generic TEE framework in the kernel, to handle
trusted environemtns (security coprocessor or software implementations
such as OP-TEE/TrustZone). I'm sending it separately from the other
arm-soc driver changes to give it a little more visibility, once the
subsystem is merged, we will likely keep this in the arm₋soc drivers
branch or have the maintainers submit pull requests directly,
depending on the patch volume.
I have reviewed earlier versions in the past, and have reviewed the
latest version in person during Linaro Connect BUD17.
Here is my overall assessment of the subsystem:
- There is clearly demand for this, both for the generic
infrastructure and the specific OP-TEE implementation.
- The code has gone through a large number of reviews, and the review
comments have all been addressed, but the reviews were not coming
up with serious issues any more and nobody volunteered to vouch for
the quality.
- The user space ioctl interface is sufficient to work with the
OP-TEE driver, and it should in principle work with other TEE
implementations that follow the GlobalPlatform[1] standards, but it
might need to be extended in minor ways depending on specific
requirements of future TEE implementations
- The main downside of the API to me is how the user space is tied to
the TEE implementation in hardware or firmware, but uses a generic
way to communicate with it. This seems to be an inherent problem
with what it is trying to do, and I could not come up with any
better solution than what is implemented here.
For a detailed history of the patch series, see
https://lkml.org/lkml/2017/3/10/1277"
* tag 'armsoc-tee' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
arm64: dt: hikey: Add optee node
Documentation: tee subsystem and op-tee driver
tee: add OP-TEE driver
tee: generic TEE subsystem
dt/bindings: add bindings for optee
Diffstat (limited to 'drivers/tee/tee_shm_pool.c')
-rw-r--r-- | drivers/tee/tee_shm_pool.c | 156 |
1 files changed, 156 insertions, 0 deletions
diff --git a/drivers/tee/tee_shm_pool.c b/drivers/tee/tee_shm_pool.c new file mode 100644 index 000000000000..fb4f8522a526 --- /dev/null +++ b/drivers/tee/tee_shm_pool.c @@ -0,0 +1,156 @@ +/* + * 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); |