Hi Olivier, On Thu, 11 Aug 2022 at 19:26, Olivier Masse <olivier.masse@xxxxxxx> wrote: > > From: Etienne Carriere <etienne.carriere@xxxxxxxxxx> > > 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. What limits you to extend this feature to non-contiguous memory buffers? I believe that should be possible with OP-TEE dynamic shared memory which gives you the granularity to register a list of pages. -Sumit > > 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@xxxxxxxxxx> > Signed-off-by: Olivier Masse <olivier.masse@xxxxxxx> > 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 > -- > 2.25.0 >
