From: Etienne Carriere etienne.carriere@linaro.org
This change allows userland to create a tee_shm object that refers to a dmabuf reference.
Userland provides a dmabuf file descriptor as buffer reference. The created tee_shm object exported as a brand new dmabuf reference used to provide a clean fd to userland. Userland shall closed this new fd to release the tee_shm object resources. The initial dmabuf resources are tracked independently through original dmabuf file descriptor.
Once the buffer is registered and until it is released, TEE driver keeps a refcount on the registered dmabuf structure.
This change only support dmabuf references that relates to physically contiguous memory buffers.
New tee_shm flag to identify tee_shm objects built from a registered dmabuf: TEE_SHM_EXT_DMA_BUF. Such tee_shm structures are flagged with TEE_SHM_EXT_DMA_BUF.
Co-Developed-by: Etienne Carriere etienne.carriere@linaro.org Signed-off-by: Olivier Masse olivier.masse@nxp.com From: https://github.com/linaro-swg/linux.git (cherry picked from commit 41e21e5c405530590dc2dd10b2a8dbe64589840f) --- drivers/tee/tee_core.c | 38 +++++++++++++++ drivers/tee/tee_shm.c | 99 +++++++++++++++++++++++++++++++++++++++- include/linux/tee_drv.h | 11 +++++ include/uapi/linux/tee.h | 29 ++++++++++++ 4 files changed, 175 insertions(+), 2 deletions(-)
diff --git a/drivers/tee/tee_core.c b/drivers/tee/tee_core.c index 8aa1a4836b92..7c45cbf85eb9 100644 --- a/drivers/tee/tee_core.c +++ b/drivers/tee/tee_core.c @@ -355,6 +355,42 @@ tee_ioctl_shm_register(struct tee_context *ctx, return ret; }
+static int tee_ioctl_shm_register_fd(struct tee_context *ctx, + struct tee_ioctl_shm_register_fd_data __user *udata) +{ + struct tee_ioctl_shm_register_fd_data data; + struct tee_shm *shm; + long ret; + + if (copy_from_user(&data, udata, sizeof(data))) + return -EFAULT; + + /* Currently no input flags are supported */ + if (data.flags) + return -EINVAL; + + shm = tee_shm_register_fd(ctx, data.fd); + if (IS_ERR(shm)) + return -EINVAL; + + data.id = shm->id; + data.flags = shm->flags; + data.size = shm->size; + + if (copy_to_user(udata, &data, sizeof(data))) + ret = -EFAULT; + else + ret = tee_shm_get_fd(shm); + + /* + * When user space closes the file descriptor the shared memory + * should be freed or if tee_shm_get_fd() failed then it will + * be freed immediately. + */ + tee_shm_put(shm); + return ret; +} + static int params_from_user(struct tee_context *ctx, struct tee_param *params, size_t num_params, struct tee_ioctl_param __user *uparams) @@ -829,6 +865,8 @@ static long tee_ioctl(struct file *filp, unsigned int cmd, unsigned long arg) return tee_ioctl_shm_alloc(ctx, uarg); case TEE_IOC_SHM_REGISTER: return tee_ioctl_shm_register(ctx, uarg); + case TEE_IOC_SHM_REGISTER_FD: + return tee_ioctl_shm_register_fd(ctx, uarg); case TEE_IOC_OPEN_SESSION: return tee_ioctl_open_session(ctx, uarg); case TEE_IOC_INVOKE: diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c index 836872467dc6..55a3fbbb022e 100644 --- a/drivers/tee/tee_shm.c +++ b/drivers/tee/tee_shm.c @@ -4,6 +4,7 @@ */ #include <linux/anon_inodes.h> #include <linux/device.h> +#include <linux/dma-buf.h> #include <linux/idr.h> #include <linux/mm.h> #include <linux/sched.h> @@ -12,6 +13,14 @@ #include <linux/uio.h> #include "tee_private.h"
+/* extra references appended to shm object for registered shared memory */ +struct tee_shm_dmabuf_ref { + struct tee_shm shm; + struct dma_buf *dmabuf; + struct dma_buf_attachment *attach; + struct sg_table *sgt; +}; + static void shm_put_kernel_pages(struct page **pages, size_t page_count) { size_t n; @@ -71,7 +80,16 @@ static void release_registered_pages(struct tee_shm *shm)
static void tee_shm_release(struct tee_device *teedev, struct tee_shm *shm) { - if (shm->flags & TEE_SHM_POOL) { + if (shm->flags & TEE_SHM_EXT_DMA_BUF) { + struct tee_shm_dmabuf_ref *ref; + + ref = container_of(shm, struct tee_shm_dmabuf_ref, shm); + dma_buf_unmap_attachment(ref->attach, ref->sgt, + DMA_BIDIRECTIONAL); + + dma_buf_detach(ref->dmabuf, ref->attach); + dma_buf_put(ref->dmabuf); + } else if (shm->flags & TEE_SHM_POOL) { teedev->pool->ops->free(teedev->pool, shm); } else if (shm->flags & TEE_SHM_DYNAMIC) { int rc = teedev->desc->ops->shm_unregister(shm->ctx, shm); @@ -195,7 +213,7 @@ struct tee_shm *tee_shm_alloc_user_buf(struct tee_context *ctx, size_t size) * tee_client_invoke_func(). The memory allocated is later freed with a * call to tee_shm_free(). * - * @returns a pointer to 'struct tee_shm' + * @returns a pointer to 'struct tee_shm' on success, and ERR_PTR on failure */ struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, size_t size) { @@ -229,6 +247,83 @@ struct tee_shm *tee_shm_alloc_priv_buf(struct tee_context *ctx, size_t size) } EXPORT_SYMBOL_GPL(tee_shm_alloc_priv_buf);
+struct tee_shm *tee_shm_register_fd(struct tee_context *ctx, int fd) +{ + struct tee_shm_dmabuf_ref *ref; + int rc; + + if (!tee_device_get(ctx->teedev)) + return ERR_PTR(-EINVAL); + + teedev_ctx_get(ctx); + + ref = kzalloc(sizeof(*ref), GFP_KERNEL); + if (!ref) { + rc = -ENOMEM; + goto err_put_tee; + } + + refcount_set(&ref->shm.refcount, 1); + ref->shm.ctx = ctx; + ref->shm.id = -1; + + ref->dmabuf = dma_buf_get(fd); + if (IS_ERR(ref->dmabuf)) { + rc = PTR_ERR(ref->dmabuf); + goto err_put_dmabuf; + } + + ref->attach = dma_buf_attach(ref->dmabuf, &ref->shm.ctx->teedev->dev); + if (IS_ERR(ref->attach)) { + rc = PTR_ERR(ref->attach); + goto err_detach; + } + + ref->sgt = dma_buf_map_attachment(ref->attach, DMA_BIDIRECTIONAL); + if (IS_ERR(ref->sgt)) { + rc = PTR_ERR(ref->sgt); + goto err_unmap_attachement; + } + + if (sg_nents(ref->sgt->sgl) != 1) { + rc = PTR_ERR(ref->sgt->sgl); + goto err_unmap_attachement; + } + + ref->shm.paddr = sg_dma_address(ref->sgt->sgl); + ref->shm.size = sg_dma_len(ref->sgt->sgl); + ref->shm.flags = TEE_SHM_EXT_DMA_BUF; + + mutex_lock(&ref->shm.ctx->teedev->mutex); + ref->shm.id = idr_alloc(&ref->shm.ctx->teedev->idr, &ref->shm, + 1, 0, GFP_KERNEL); + mutex_unlock(&ref->shm.ctx->teedev->mutex); + if (ref->shm.id < 0) { + rc = ref->shm.id; + goto err_idr_remove; + } + + return &ref->shm; + +err_idr_remove: + mutex_lock(&ctx->teedev->mutex); + idr_remove(&ctx->teedev->idr, ref->shm.id); + mutex_unlock(&ctx->teedev->mutex); +err_unmap_attachement: + dma_buf_unmap_attachment(ref->attach, ref->sgt, DMA_BIDIRECTIONAL); +err_detach: + dma_buf_detach(ref->dmabuf, ref->attach); +err_put_dmabuf: + dma_buf_put(ref->dmabuf); + kfree(ref); +err_put_tee: + teedev_ctx_put(ctx); + tee_device_put(ctx->teedev); + + return ERR_PTR(rc); +} +EXPORT_SYMBOL_GPL(tee_shm_register_fd); + static struct tee_shm * register_shm_helper(struct tee_context *ctx, unsigned long addr, size_t length, u32 flags, int id) diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h index 911cad324acc..40ddd5376c2d 100644 --- a/include/linux/tee_drv.h +++ b/include/linux/tee_drv.h @@ -25,6 +25,7 @@ #define TEE_SHM_USER_MAPPED BIT(1) /* Memory mapped in user space */ #define TEE_SHM_POOL BIT(2) /* Memory allocated from pool */ #define TEE_SHM_PRIV BIT(3) /* Memory private to TEE driver */ +#define TEE_SHM_EXT_DMA_BUF BIT(4) /* Memory with dma-buf handle */
struct device; struct tee_device; @@ -276,6 +277,16 @@ struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, size_t size); struct tee_shm *tee_shm_register_kernel_buf(struct tee_context *ctx, void *addr, size_t length);
+/** + * tee_shm_register_fd() - Register shared memory from file descriptor + * + * @ctx: Context that allocates the shared memory + * @fd: Shared memory file descriptor reference + * + * @returns a pointer to 'struct tee_shm' on success, and ERR_PTR on failure + */ +struct tee_shm *tee_shm_register_fd(struct tee_context *ctx, int fd); + /** * tee_shm_is_dynamic() - Check if shared memory object is of the dynamic kind * @shm: Shared memory handle diff --git a/include/uapi/linux/tee.h b/include/uapi/linux/tee.h index 25a6c534beb1..6f84060ad005 100644 --- a/include/uapi/linux/tee.h +++ b/include/uapi/linux/tee.h @@ -121,6 +121,35 @@ struct tee_ioctl_shm_alloc_data { #define TEE_IOC_SHM_ALLOC _IOWR(TEE_IOC_MAGIC, TEE_IOC_BASE + 1, \ struct tee_ioctl_shm_alloc_data)
+/** + * struct tee_ioctl_shm_register_fd_data - Shared memory registering argument + * @fd: [in] File descriptor identifying the shared memory + * @size: [out] Size of shared memory to allocate + * @flags: [in] Flags to/from allocation. + * @id: [out] Identifier of the shared memory + * + * The flags field should currently be zero as input. Updated by the call + * with actual flags as defined by TEE_IOCTL_SHM_* above. + * This structure is used as argument for TEE_IOC_SHM_REGISTER_FD below. + */ +struct tee_ioctl_shm_register_fd_data { + __s64 fd; + __u64 size; + __u32 flags; + __s32 id; +} __aligned(8); + +/** + * TEE_IOC_SHM_REGISTER_FD - register a shared memory from a file descriptor + * + * Returns a file descriptor on success or < 0 on failure + * + * The returned file descriptor refers to the shared memory object in kernel + * land. The shared memory is freed when the descriptor is closed. + */ +#define TEE_IOC_SHM_REGISTER_FD _IOWR(TEE_IOC_MAGIC, TEE_IOC_BASE + 8, \ + struct tee_ioctl_shm_register_fd_data) + /** * struct tee_ioctl_buf_data - Variable sized buffer * @buf_ptr: [in] A __user pointer to a buffer