diff options
author | Jens Wiklander <jens.wiklander@linaro.org> | 2015-03-11 16:39:39 +0300 |
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committer | Jens Wiklander <jens.wiklander@linaro.org> | 2017-03-09 17:42:33 +0300 |
commit | 967c9cca2cc50569efc65945325c173cecba83bd (patch) | |
tree | cf64178161ee3ba1cb18762604b82f2df7738c33 /drivers/tee/tee_shm.c | |
parent | c8bfafb1594435889b571b79325011e8b7fd087b (diff) |
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>
Diffstat (limited to 'drivers/tee/tee_shm.c')
-rw-r--r-- | drivers/tee/tee_shm.c | 358 |
1 files changed, 358 insertions, 0 deletions
diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c new file mode 100644 index 000000000000..0be1e3e93bee --- /dev/null +++ b/drivers/tee/tee_shm.c @@ -0,0 +1,358 @@ +/* + * 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); |