[v3,4/4] optee: support restricted memory allocation

Add support in the OP-TEE backend driver for restricted memory
allocation.

The restricted memory can be allocated from a static carveout, but also
be dynamically allocated from CMA and turned into restricted memory by
OP-TEE, inaccessible by the kernel. The restricted memory configuration
is depends on the platform and is probed by driver.

A restricted memory pool is allocated during probe if a static carveout
is available. The restricted memory pools for dynamically allocated
restrict memory are instantiated when requested by user-space. This
instantiation can fail if OP-TEE doesn't support the requested use-case
of restricted memory.

Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
---
 drivers/tee/optee/Makefile        |   1 +
 drivers/tee/optee/core.c          |   1 +
 drivers/tee/optee/ffa_abi.c       | 135 ++++++++++-
 drivers/tee/optee/optee_private.h |  33 ++-
 drivers/tee/optee/rstmem.c        | 380 ++++++++++++++++++++++++++++++
 drivers/tee/optee/smc_abi.c       | 138 ++++++++++-
 6 files changed, 683 insertions(+), 5 deletions(-)
 create mode 100644 drivers/tee/optee/rstmem.c

Hi Sumit,

On Tue, Dec 3, 2024 at 9:19 AM Sumit Garg <sumit.garg@linaro.org> wrote:
>
> Hi Jens,
>
> On Thu, 28 Nov 2024 at 20:39, Jens Wiklander <jens.wiklander@linaro.org> wrote:
> >
> > Add support in the OP-TEE backend driver for restricted memory
> > allocation.
> >
> > The restricted memory can be allocated from a static carveout, but also
> > be dynamically allocated from CMA and turned into restricted memory by
> > OP-TEE, inaccessible by the kernel. The restricted memory configuration
> > is depends on the platform and is probed by driver.
> >
> > A restricted memory pool is allocated during probe if a static carveout
> > is available. The restricted memory pools for dynamically allocated
> > restrict memory are instantiated when requested by user-space. This
> > instantiation can fail if OP-TEE doesn't support the requested use-case
> > of restricted memory.
>
> Can we split this patch into smaller reviewable pieces as follows?
>
> - Patch 1: Adds support for static carveout using SMC ABI
> - Patch 2: Adds support for dynamic CMA pool using SMC ABI
> - Patch 3: Adds support for both using FF-A ABI

OK, I'll split it.

Thanks,
Jens

>
> -Sumit
>
> >
> > Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
> > ---
> >  drivers/tee/optee/Makefile        |   1 +
> >  drivers/tee/optee/core.c          |   1 +
> >  drivers/tee/optee/ffa_abi.c       | 135 ++++++++++-
> >  drivers/tee/optee/optee_private.h |  33 ++-
> >  drivers/tee/optee/rstmem.c        | 380 ++++++++++++++++++++++++++++++
> >  drivers/tee/optee/smc_abi.c       | 138 ++++++++++-
> >  6 files changed, 683 insertions(+), 5 deletions(-)
> >  create mode 100644 drivers/tee/optee/rstmem.c
> >
> > diff --git a/drivers/tee/optee/Makefile b/drivers/tee/optee/Makefile
> > index a6eff388d300..498969fb8e40 100644
> > --- a/drivers/tee/optee/Makefile
> > +++ b/drivers/tee/optee/Makefile
> > @@ -4,6 +4,7 @@ optee-objs += core.o
> >  optee-objs += call.o
> >  optee-objs += notif.o
> >  optee-objs += rpc.o
> > +optee-objs += rstmem.o
> >  optee-objs += supp.o
> >  optee-objs += device.o
> >  optee-objs += smc_abi.o
> > diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c
> > index c75fddc83576..f4fa494789a4 100644
> > --- a/drivers/tee/optee/core.c
> > +++ b/drivers/tee/optee/core.c
> > @@ -182,6 +182,7 @@ void optee_remove_common(struct optee *optee)
> >         tee_device_unregister(optee->teedev);
> >
> >         tee_shm_pool_free(optee->pool);
> > +       optee_rstmem_pools_uninit(optee);
> >         optee_supp_uninit(&optee->supp);
> >         mutex_destroy(&optee->call_queue.mutex);
> >         rpmb_dev_put(optee->rpmb_dev);
> > diff --git a/drivers/tee/optee/ffa_abi.c b/drivers/tee/optee/ffa_abi.c
> > index 02e6175ac5f0..f500cf101c8d 100644
> > --- a/drivers/tee/optee/ffa_abi.c
> > +++ b/drivers/tee/optee/ffa_abi.c
> > @@ -672,6 +672,122 @@ static int optee_ffa_do_call_with_arg(struct tee_context *ctx,
> >         return optee_ffa_yielding_call(ctx, &data, rpc_arg, system_thread);
> >  }
> >
> > +static int do_call_lend_rstmem(struct optee *optee, u64 cookie, u32 use_case)
> > +{
> > +       struct optee_shm_arg_entry *entry;
> > +       struct optee_msg_arg *msg_arg;
> > +       struct tee_shm *shm;
> > +       u_int offs;
> > +       int rc;
> > +
> > +       msg_arg = optee_get_msg_arg(optee->ctx, 1, &entry, &shm, &offs);
> > +       if (IS_ERR(msg_arg))
> > +               return PTR_ERR(msg_arg);
> > +
> > +       msg_arg->cmd = OPTEE_MSG_CMD_ASSIGN_RSTMEM;
> > +       msg_arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_VALUE_INPUT;
> > +       msg_arg->params[0].u.value.a = cookie;
> > +       msg_arg->params[0].u.value.b = use_case;
> > +
> > +       rc = optee->ops->do_call_with_arg(optee->ctx, shm, offs, false);
> > +       if (rc)
> > +               goto out;
> > +       if (msg_arg->ret != TEEC_SUCCESS) {
> > +               rc = -EINVAL;
> > +               goto out;
> > +       }
> > +
> > +out:
> > +       optee_free_msg_arg(optee->ctx, entry, offs);
> > +       return rc;
> > +}
> > +
> > +static int optee_ffa_lend_rstmem(struct optee *optee, struct tee_shm *rstmem,
> > +                                u16 *end_points, unsigned int ep_count)
> > +{
> > +       struct ffa_device *ffa_dev = optee->ffa.ffa_dev;
> > +       const struct ffa_mem_ops *mem_ops = ffa_dev->ops->mem_ops;
> > +       const struct ffa_msg_ops *msg_ops = ffa_dev->ops->msg_ops;
> > +       struct ffa_send_direct_data data;
> > +       struct ffa_mem_region_attributes *mem_attr;
> > +       struct ffa_mem_ops_args args = {
> > +               .use_txbuf = true,
> > +               .tag = rstmem->use_case,
> > +       };
> > +       struct page *page;
> > +       struct scatterlist sgl;
> > +       unsigned int n;
> > +       int rc;
> > +
> > +       mem_attr = kcalloc(ep_count, sizeof(*mem_attr), GFP_KERNEL);
> > +       for (n = 0; n < ep_count; n++) {
> > +               mem_attr[n].receiver = end_points[n];
> > +               mem_attr[n].attrs = FFA_MEM_RW;
> > +       }
> > +       args.attrs = mem_attr;
> > +       args.nattrs = ep_count;
> > +
> > +       page = phys_to_page(rstmem->paddr);
> > +       sg_init_table(&sgl, 1);
> > +       sg_set_page(&sgl, page, rstmem->size, 0);
> > +
> > +       args.sg = &sgl;
> > +       rc = mem_ops->memory_lend(&args);
> > +       kfree(mem_attr);
> > +       if (rc)
> > +               return rc;
> > +
> > +       rc = do_call_lend_rstmem(optee, args.g_handle, rstmem->use_case);
> > +       if (rc)
> > +               goto err_reclaim;
> > +
> > +       rc = optee_shm_add_ffa_handle(optee, rstmem, args.g_handle);
> > +       if (rc)
> > +               goto err_unreg;
> > +
> > +       rstmem->sec_world_id = args.g_handle;
> > +
> > +       return 0;
> > +
> > +err_unreg:
> > +       data = (struct ffa_send_direct_data){
> > +               .data0 = OPTEE_FFA_RELEASE_RSTMEM,
> > +               .data1 = (u32)args.g_handle,
> > +               .data2 = (u32)(args.g_handle >> 32),
> > +       };
> > +       msg_ops->sync_send_receive(ffa_dev, &data);
> > +err_reclaim:
> > +       mem_ops->memory_reclaim(args.g_handle, 0);
> > +       return rc;
> > +}
> > +
> > +static int optee_ffa_reclaim_rstmem(struct optee *optee, struct tee_shm *rstmem)
> > +{
> > +       struct ffa_device *ffa_dev = optee->ffa.ffa_dev;
> > +       const struct ffa_msg_ops *msg_ops = ffa_dev->ops->msg_ops;
> > +       const struct ffa_mem_ops *mem_ops = ffa_dev->ops->mem_ops;
> > +       u64 global_handle = rstmem->sec_world_id;
> > +       struct ffa_send_direct_data data = {
> > +               .data0 = OPTEE_FFA_RELEASE_RSTMEM,
> > +               .data1 = (u32)global_handle,
> > +               .data2 = (u32)(global_handle >> 32)
> > +       };
> > +       int rc;
> > +
> > +       optee_shm_rem_ffa_handle(optee, global_handle);
> > +       rstmem->sec_world_id = 0;
> > +
> > +       rc = msg_ops->sync_send_receive(ffa_dev, &data);
> > +       if (rc)
> > +               pr_err("Release SHM id 0x%llx rc %d\n", global_handle, rc);
> > +
> > +       rc = mem_ops->memory_reclaim(global_handle, 0);
> > +       if (rc)
> > +               pr_err("mem_reclaim: 0x%llx %d", global_handle, rc);
> > +
> > +       return rc;
> > +}
> > +
> >  /*
> >   * 6. Driver initialization
> >   *
> > @@ -785,7 +901,10 @@ static void optee_ffa_get_version(struct tee_device *teedev,
> >                 .gen_caps = TEE_GEN_CAP_GP | TEE_GEN_CAP_REG_MEM |
> >                             TEE_GEN_CAP_MEMREF_NULL,
> >         };
> > +       struct optee *optee = tee_get_drvdata(teedev);
> >
> > +       if (optee->rstmem_pools)
> > +               v.gen_caps |= TEE_GEN_CAP_RSTMEM;
> >         *vers = v;
> >  }
> >
> > @@ -804,6 +923,8 @@ static const struct tee_driver_ops optee_ffa_clnt_ops = {
> >         .cancel_req = optee_cancel_req,
> >         .shm_register = optee_ffa_shm_register,
> >         .shm_unregister = optee_ffa_shm_unregister,
> > +       .rstmem_alloc = optee_rstmem_alloc,
> > +       .rstmem_free = optee_rstmem_free,
> >  };
> >
> >  static const struct tee_desc optee_ffa_clnt_desc = {
> > @@ -820,6 +941,8 @@ static const struct tee_driver_ops optee_ffa_supp_ops = {
> >         .supp_send = optee_supp_send,
> >         .shm_register = optee_ffa_shm_register, /* same as for clnt ops */
> >         .shm_unregister = optee_ffa_shm_unregister_supp,
> > +       .rstmem_alloc = optee_rstmem_alloc,
> > +       .rstmem_free = optee_rstmem_free,
> >  };
> >
> >  static const struct tee_desc optee_ffa_supp_desc = {
> > @@ -833,6 +956,8 @@ static const struct optee_ops optee_ffa_ops = {
> >         .do_call_with_arg = optee_ffa_do_call_with_arg,
> >         .to_msg_param = optee_ffa_to_msg_param,
> >         .from_msg_param = optee_ffa_from_msg_param,
> > +       .lend_rstmem = optee_ffa_lend_rstmem,
> > +       .reclaim_rstmem = optee_ffa_reclaim_rstmem,
> >  };
> >
> >  static void optee_ffa_remove(struct ffa_device *ffa_dev)
> > @@ -937,11 +1062,17 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
> >             (sec_caps & OPTEE_FFA_SEC_CAP_RPMB_PROBE))
> >                 optee->in_kernel_rpmb_routing = true;
> >
> > +       if (sec_caps & OPTEE_FFA_SEC_CAP_RSTMEM) {
> > +               rc = optee_rstmem_pools_init(optee);
> > +               if (rc)
> > +                       goto err_free_pool;
> > +       }
> > +
> >         teedev = tee_device_alloc(&optee_ffa_clnt_desc, NULL, optee->pool,
> >                                   optee);
> >         if (IS_ERR(teedev)) {
> >                 rc = PTR_ERR(teedev);
> > -               goto err_free_pool;
> > +               goto err_free_rstmem_pools;
> >         }
> >         optee->teedev = teedev;
> >
> > @@ -1020,6 +1151,8 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
> >         tee_device_unregister(optee->teedev);
> >  err_free_pool:
> >         tee_shm_pool_free(pool);
> > +err_free_rstmem_pools:
> > +       optee_rstmem_pools_uninit(optee);
> >  err_free_optee:
> >         kfree(optee);
> >         return rc;
> > diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h
> > index 20eda508dbac..dd2a3a2224bc 100644
> > --- a/drivers/tee/optee/optee_private.h
> > +++ b/drivers/tee/optee/optee_private.h
> > @@ -174,9 +174,14 @@ struct optee;
> >   * @do_call_with_arg:  enters OP-TEE in secure world
> >   * @to_msg_param:      converts from struct tee_param to OPTEE_MSG parameters
> >   * @from_msg_param:    converts from OPTEE_MSG parameters to struct tee_param
> > + * @lend_rstmem:       lends physically contiguous memory as restricted
> > + *                     memory, inaccessible by the kernel
> > + * @reclaim_rstmem:    reclaims restricted memory previously lent with
> > + *                     @lend_rstmem() and makes it accessible by the
> > + *                     kernel again
> >   *
> >   * These OPs are only supposed to be used internally in the OP-TEE driver
> > - * as a way of abstracting the different methogs of entering OP-TEE in
> > + * as a way of abstracting the different methods of entering OP-TEE in
> >   * secure world.
> >   */
> >  struct optee_ops {
> > @@ -191,6 +196,23 @@ struct optee_ops {
> >                               size_t num_params,
> >                               const struct optee_msg_param *msg_params,
> >                               bool update_out);
> > +       int (*lend_rstmem)(struct optee *optee, struct tee_shm *rstmem,
> > +                          u16 *end_points, unsigned int ep_count);
> > +       int (*reclaim_rstmem)(struct optee *optee, struct tee_shm *rstmem);
> > +};
> > +
> > +/**
> > + * struct optee_rstmem_pools - restricted memory pools
> > + * @mutex:     serializes write access to @xa when adding a new pool.
> > + * @xa:                XArray of struct tee_shm_pool where the index is the
> > + *             use case ID TEE_IOC_UC_* supplied for TEE_IOC_RSTMEM_ALLOC.
> > + */
> > +struct optee_rstmem_pools {
> > +       /*
> > +        * Serializes write access to @xa when adding a new pool.
> > +        */
> > +       struct mutex mutex;
> > +       struct xarray xa;
> >  };
> >
> >  /**
> > @@ -206,6 +228,7 @@ struct optee_ops {
> >   * @notif:             notification synchronization struct
> >   * @supp:              supplicant synchronization struct for RPC to supplicant
> >   * @pool:              shared memory pool
> > + * @rstmem_pool:       restricted memory pool for secure data path
> >   * @mutex:             mutex protecting @rpmb_dev
> >   * @rpmb_dev:          current RPMB device or NULL
> >   * @rpmb_scan_bus_done flag if device registation of RPMB dependent devices
> > @@ -230,6 +253,7 @@ struct optee {
> >         struct optee_notif notif;
> >         struct optee_supp supp;
> >         struct tee_shm_pool *pool;
> > +       struct optee_rstmem_pools *rstmem_pools;
> >         /* Protects rpmb_dev pointer */
> >         struct mutex rpmb_dev_mutex;
> >         struct rpmb_dev *rpmb_dev;
> > @@ -286,6 +310,9 @@ void optee_supp_init(struct optee_supp *supp);
> >  void optee_supp_uninit(struct optee_supp *supp);
> >  void optee_supp_release(struct optee_supp *supp);
> >
> > +int optee_rstmem_pools_init(struct optee *optee);
> > +void optee_rstmem_pools_uninit(struct optee *optee);
> > +
> >  int optee_supp_recv(struct tee_context *ctx, u32 *func, u32 *num_params,
> >                     struct tee_param *param);
> >  int optee_supp_send(struct tee_context *ctx, u32 ret, u32 num_params,
> > @@ -378,6 +405,10 @@ void optee_rpc_cmd(struct tee_context *ctx, struct optee *optee,
> >  int optee_do_bottom_half(struct tee_context *ctx);
> >  int optee_stop_async_notif(struct tee_context *ctx);
> >
> > +int optee_rstmem_alloc(struct tee_context *ctx, struct tee_shm *shm,
> > +                      u32 flags, u32 use_case, size_t size);
> > +void optee_rstmem_free(struct tee_context *ctx, struct tee_shm *shm);
> > +
> >  /*
> >   * Small helpers
> >   */
> > diff --git a/drivers/tee/optee/rstmem.c b/drivers/tee/optee/rstmem.c
> > new file mode 100644
> > index 000000000000..cf300929171f
> > --- /dev/null
> > +++ b/drivers/tee/optee/rstmem.c
> > @@ -0,0 +1,380 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * Copyright (c) 2024, Linaro Limited
> > + */
> > +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> > +
> > +#include <linux/cma.h>
> > +#include <linux/dma-map-ops.h>
> > +#include <linux/errno.h>
> > +#include <linux/genalloc.h>
> > +#include <linux/slab.h>
> > +#include <linux/string.h>
> > +#include <linux/tee_core.h>
> > +#include <linux/types.h>
> > +#include "optee_private.h"
> > +
> > +struct optee_rstmem_cma_pool {
> > +       struct tee_shm_pool pool;
> > +       struct page *page;
> > +       struct optee *optee;
> > +       size_t page_count;
> > +       u16 *end_points;
> > +       u_int end_point_count;
> > +       u_int align;
> > +       refcount_t refcount;
> > +       struct tee_shm rstmem;
> > +       /* Protects when initializing and tearing down this struct */
> > +       struct mutex mutex;
> > +};
> > +
> > +static struct optee_rstmem_cma_pool *
> > +to_rstmem_cma_pool(struct tee_shm_pool *pool)
> > +{
> > +       return container_of(pool, struct optee_rstmem_cma_pool, pool);
> > +}
> > +
> > +static int init_cma_rstmem(struct optee_rstmem_cma_pool *rp)
> > +{
> > +       struct cma *cma = dev_get_cma_area(&rp->optee->teedev->dev);
> > +       int rc;
> > +
> > +       rp->page = cma_alloc(cma, rp->page_count, rp->align, true/*no_warn*/);
> > +       if (!rp->page)
> > +               return -ENOMEM;
> > +
> > +       /*
> > +        * TODO unmap the memory range since the physical memory will
> > +        * become inaccesible after the lend_rstmem() call.
> > +        */
> > +
> > +       rp->rstmem.paddr = page_to_phys(rp->page);
> > +       rp->rstmem.size = rp->page_count * PAGE_SIZE;
> > +       rc = rp->optee->ops->lend_rstmem(rp->optee, &rp->rstmem,
> > +                                        rp->end_points, rp->end_point_count);
> > +       if (rc)
> > +               goto err_release;
> > +
> > +       rp->pool.private_data = gen_pool_create(PAGE_SHIFT, -1);
> > +       if (!rp->pool.private_data) {
> > +               rc = -ENOMEM;
> > +               goto err_reclaim;
> > +       }
> > +
> > +       rc = gen_pool_add(rp->pool.private_data, rp->rstmem.paddr,
> > +                         rp->rstmem.size, -1);
> > +       if (rc)
> > +               goto err_free_pool;
> > +
> > +       refcount_set(&rp->refcount, 1);
> > +       return 0;
> > +
> > +err_free_pool:
> > +       gen_pool_destroy(rp->pool.private_data);
> > +err_reclaim:
> > +       rp->optee->ops->reclaim_rstmem(rp->optee, &rp->rstmem);
> > +err_release:
> > +       cma_release(cma, rp->page, rp->page_count);
> > +       rp->rstmem.paddr = 0;
> > +       rp->rstmem.size = 0;
> > +       rp->rstmem.sec_world_id = 0;
> > +       return rc;
> > +}
> > +
> > +static int get_cma_rstmem(struct optee_rstmem_cma_pool *rp)
> > +{
> > +       int rc = 0;
> > +
> > +       if (!refcount_inc_not_zero(&rp->refcount)) {
> > +               mutex_lock(&rp->mutex);
> > +               if (rp->pool.private_data) {
> > +                       /*
> > +                        * Another thread has already initialized the pool
> > +                        * before us, or the pool was just about to be torn
> > +                        * down. Either way we only need to increase the
> > +                        * refcount and we're done.
> > +                        */
> > +                       refcount_inc(&rp->refcount);
> > +               } else {
> > +                       rc = init_cma_rstmem(rp);
> > +               }
> > +               mutex_unlock(&rp->mutex);
> > +       }
> > +
> > +       return rc;
> > +}
> > +
> > +static void release_cma_rstmem(struct optee_rstmem_cma_pool *rp)
> > +{
> > +       gen_pool_destroy(rp->pool.private_data);
> > +       rp->optee->ops->reclaim_rstmem(rp->optee, &rp->rstmem);
> > +       cma_release(dev_get_cma_area(&rp->optee->teedev->dev), rp->page,
> > +                   rp->page_count);
> > +
> > +       rp->pool.private_data = NULL;
> > +       rp->page = NULL;
> > +       rp->rstmem.paddr = 0;
> > +       rp->rstmem.size = 0;
> > +       rp->rstmem.sec_world_id = 0;
> > +}
> > +
> > +static void put_cma_rstmem(struct optee_rstmem_cma_pool *rp)
> > +{
> > +       if (refcount_dec_and_test(&rp->refcount)) {
> > +               mutex_lock(&rp->mutex);
> > +               if (rp->pool.private_data)
> > +                       release_cma_rstmem(rp);
> > +               mutex_unlock(&rp->mutex);
> > +       }
> > +}
> > +
> > +static int rstmem_pool_op_cma_alloc(struct tee_shm_pool *pool,
> > +                                   struct tee_shm *shm, size_t size,
> > +                                   size_t align)
> > +{
> > +       struct optee_rstmem_cma_pool *rp = to_rstmem_cma_pool(pool);
> > +       size_t sz = ALIGN(size, PAGE_SIZE);
> > +       phys_addr_t pa;
> > +       int rc;
> > +
> > +       rc = get_cma_rstmem(rp);
> > +       if (rc)
> > +               return rc;
> > +
> > +       pa = gen_pool_alloc(rp->pool.private_data, sz);
> > +       if (!pa) {
> > +               put_cma_rstmem(rp);
> > +               return -ENOMEM;
> > +       }
> > +
> > +       shm->size = sz;
> > +       shm->paddr = pa;
> > +       shm->offset = pa - page_to_phys(rp->page);
> > +       shm->sec_world_id = rp->rstmem.sec_world_id;
> > +
> > +       return 0;
> > +}
> > +
> > +static void rstmem_pool_op_cma_free(struct tee_shm_pool *pool,
> > +                                   struct tee_shm *shm)
> > +{
> > +       struct optee_rstmem_cma_pool *rp = to_rstmem_cma_pool(pool);
> > +
> > +       gen_pool_free(rp->pool.private_data, shm->paddr, shm->size);
> > +       shm->size = 0;
> > +       shm->paddr = 0;
> > +       shm->offset = 0;
> > +       shm->sec_world_id = 0;
> > +       put_cma_rstmem(rp);
> > +}
> > +
> > +static void pool_op_cma_destroy_pool(struct tee_shm_pool *pool)
> > +{
> > +       struct optee_rstmem_cma_pool *rp = to_rstmem_cma_pool(pool);
> > +
> > +       mutex_destroy(&rp->mutex);
> > +       kfree(rp);
> > +}
> > +
> > +static struct tee_shm_pool_ops rstmem_pool_ops_cma = {
> > +       .alloc = rstmem_pool_op_cma_alloc,
> > +       .free = rstmem_pool_op_cma_free,
> > +       .destroy_pool = pool_op_cma_destroy_pool,
> > +};
> > +
> > +static int get_rstmem_config(struct optee *optee, u32 use_case,
> > +                            size_t *min_size, u_int *min_align,
> > +                            u16 *end_points, u_int *ep_count)
> > +{
> > +       struct tee_param params[2] = {
> > +               [0] = {
> > +                       .attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT,
> > +                       .u.value.a = use_case,
> > +               },
> > +               [1] = {
> > +                       .attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT,
> > +               },
> > +       };
> > +       struct optee_shm_arg_entry *entry;
> > +       struct tee_shm *shm_param = NULL;
> > +       struct optee_msg_arg *msg_arg;
> > +       struct tee_shm *shm;
> > +       u_int offs;
> > +       int rc;
> > +
> > +       if (end_points && *ep_count) {
> > +               params[1].u.memref.size = *ep_count * sizeof(*end_points);
> > +               shm_param = tee_shm_alloc_priv_buf(optee->ctx,
> > +                                                  params[1].u.memref.size);
> > +               if (IS_ERR(shm_param))
> > +                       return PTR_ERR(shm_param);
> > +               params[1].u.memref.shm = shm_param;
> > +       }
> > +
> > +       msg_arg = optee_get_msg_arg(optee->ctx, ARRAY_SIZE(params), &entry,
> > +                                   &shm, &offs);
> > +       if (IS_ERR(msg_arg)) {
> > +               rc = PTR_ERR(msg_arg);
> > +               goto out_free_shm;
> > +       }
> > +       msg_arg->cmd = OPTEE_MSG_CMD_GET_RSTMEM_CONFIG;
> > +
> > +       rc = optee->ops->to_msg_param(optee, msg_arg->params,
> > +                                     ARRAY_SIZE(params), params,
> > +                                     false /*!update_out*/);
> > +       if (rc)
> > +               goto out_free_msg;
> > +
> > +       rc = optee->ops->do_call_with_arg(optee->ctx, shm, offs, false);
> > +       if (rc)
> > +               goto out_free_msg;
> > +       if (msg_arg->ret && msg_arg->ret != TEEC_ERROR_SHORT_BUFFER) {
> > +               rc = -EINVAL;
> > +               goto out_free_msg;
> > +       }
> > +
> > +       rc = optee->ops->from_msg_param(optee, params, ARRAY_SIZE(params),
> > +                                       msg_arg->params, true /*update_out*/);
> > +       if (rc)
> > +               goto out_free_msg;
> > +
> > +       if (!msg_arg->ret && end_points &&
> > +           *ep_count < params[1].u.memref.size / sizeof(u16)) {
> > +               rc = -EINVAL;
> > +               goto out_free_msg;
> > +       }
> > +
> > +       *min_size = params[0].u.value.a;
> > +       *min_align = params[0].u.value.b;
> > +       *ep_count = params[1].u.memref.size / sizeof(u16);
> > +
> > +       if (msg_arg->ret == TEEC_ERROR_SHORT_BUFFER) {
> > +               rc = -ENOSPC;
> > +               goto out_free_msg;
> > +       }
> > +
> > +       if (end_points)
> > +               memcpy(end_points, tee_shm_get_va(shm_param, 0),
> > +                      params[1].u.memref.size);
> > +
> > +out_free_msg:
> > +       optee_free_msg_arg(optee->ctx, entry, offs);
> > +out_free_shm:
> > +       if (shm_param)
> > +               tee_shm_free(shm_param);
> > +       return rc;
> > +}
> > +
> > +static struct tee_shm_pool *alloc_rstmem_pool(struct optee *optee, u32 use_case)
> > +{
> > +       struct optee_rstmem_cma_pool *rp;
> > +       size_t min_size;
> > +       int rc;
> > +
> > +       rp = kzalloc(sizeof(*rp), GFP_KERNEL);
> > +       if (!rp)
> > +               return ERR_PTR(-ENOMEM);
> > +       rp->rstmem.use_case = use_case;
> > +
> > +       rc = get_rstmem_config(optee, use_case, &min_size, &rp->align, NULL,
> > +                              &rp->end_point_count);
> > +       if (rc) {
> > +               if (rc != -ENOSPC)
> > +                       goto err;
> > +               rp->end_points = kcalloc(rp->end_point_count,
> > +                                        sizeof(*rp->end_points), GFP_KERNEL);
> > +               if (!rp->end_points) {
> > +                       rc = -ENOMEM;
> > +                       goto err;
> > +               }
> > +               rc = get_rstmem_config(optee, use_case, &min_size, &rp->align,
> > +                                      rp->end_points, &rp->end_point_count);
> > +               if (rc)
> > +                       goto err_kfree_eps;
> > +       }
> > +
> > +       rp->pool.ops = &rstmem_pool_ops_cma;
> > +       rp->optee = optee;
> > +       rp->page_count = min_size / PAGE_SIZE;
> > +       mutex_init(&rp->mutex);
> > +
> > +       return &rp->pool;
> > +
> > +err_kfree_eps:
> > +       kfree(rp->end_points);
> > +err:
> > +       kfree(rp);
> > +       return ERR_PTR(rc);
> > +}
> > +
> > +int optee_rstmem_alloc(struct tee_context *ctx, struct tee_shm *shm,
> > +                      u32 flags, u32 use_case, size_t size)
> > +{
> > +       struct optee *optee = tee_get_drvdata(ctx->teedev);
> > +       struct tee_shm_pool *pool;
> > +       int rc;
> > +
> > +       if (!optee->rstmem_pools)
> > +               return -EINVAL;
> > +       if (flags)
> > +               return -EINVAL;
> > +
> > +       pool = xa_load(&optee->rstmem_pools->xa, use_case);
> > +       if (!pool) {
> > +               pool = alloc_rstmem_pool(optee, use_case);
> > +               if (IS_ERR(pool))
> > +                       return PTR_ERR(pool);
> > +               rc = xa_insert(&optee->rstmem_pools->xa, use_case, pool,
> > +                              GFP_KERNEL);
> > +               if (rc) {
> > +                       pool->ops->destroy_pool(pool);
> > +                       return rc;
> > +               }
> > +       }
> > +
> > +       return pool->ops->alloc(pool, shm, size, 0);
> > +}
> > +
> > +void optee_rstmem_free(struct tee_context *ctx, struct tee_shm *shm)
> > +{
> > +       struct optee *optee = tee_get_drvdata(ctx->teedev);
> > +       struct tee_shm_pool *pool;
> > +
> > +       pool = xa_load(&optee->rstmem_pools->xa, shm->use_case);
> > +       if (pool)
> > +               pool->ops->free(pool, shm);
> > +       else
> > +               pr_err("Can't find pool for use_case %u\n", shm->use_case);
> > +}
> > +
> > +int optee_rstmem_pools_init(struct optee *optee)
> > +{
> > +       struct optee_rstmem_pools *pools;
> > +
> > +       pools = kmalloc(sizeof(*pools), GFP_KERNEL);
> > +       if (!pools)
> > +               return -ENOMEM;
> > +
> > +       mutex_init(&pools->mutex);
> > +       xa_init(&pools->xa);
> > +       optee->rstmem_pools = pools;
> > +       return 0;
> > +}
> > +
> > +void optee_rstmem_pools_uninit(struct optee *optee)
> > +{
> > +       if (optee->rstmem_pools) {
> > +               struct tee_shm_pool *pool;
> > +               u_long idx;
> > +
> > +               xa_for_each(&optee->rstmem_pools->xa, idx, pool) {
> > +                       xa_erase(&optee->rstmem_pools->xa, idx);
> > +                       pool->ops->destroy_pool(pool);
> > +               }
> > +
> > +               xa_destroy(&optee->rstmem_pools->xa);
> > +               mutex_destroy(&optee->rstmem_pools->mutex);
> > +               kfree(optee->rstmem_pools);
> > +               optee->rstmem_pools = NULL;
> > +       }
> > +}
> > diff --git a/drivers/tee/optee/smc_abi.c b/drivers/tee/optee/smc_abi.c
> > index d1f79947f58a..7fa7d9d14c94 100644
> > --- a/drivers/tee/optee/smc_abi.c
> > +++ b/drivers/tee/optee/smc_abi.c
> > @@ -1001,6 +1001,67 @@ static int optee_smc_do_call_with_arg(struct tee_context *ctx,
> >         return rc;
> >  }
> >
> > +static int optee_smc_lend_rstmem(struct optee *optee, struct tee_shm *rstmem,
> > +                                u16 *end_points, unsigned int ep_count)
> > +{
> > +       struct optee_shm_arg_entry *entry;
> > +       struct optee_msg_arg *msg_arg;
> > +       struct tee_shm *shm;
> > +       u_int offs;
> > +       int rc;
> > +
> > +       msg_arg = optee_get_msg_arg(optee->ctx, 2, &entry, &shm, &offs);
> > +       if (IS_ERR(msg_arg))
> > +               return PTR_ERR(msg_arg);
> > +
> > +       msg_arg->cmd = OPTEE_MSG_CMD_LEND_RSTMEM;
> > +       msg_arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_VALUE_INPUT;
> > +       msg_arg->params[0].u.value.a = OPTEE_MSG_RSTMEM_SECURE_VIDEO_PLAY;
> > +       msg_arg->params[1].attr = OPTEE_MSG_ATTR_TYPE_TMEM_INPUT;
> > +       msg_arg->params[1].u.tmem.buf_ptr = rstmem->paddr;
> > +       msg_arg->params[1].u.tmem.size = rstmem->size;
> > +       msg_arg->params[1].u.tmem.shm_ref = (u_long)rstmem;
> > +
> > +       rc = optee->ops->do_call_with_arg(optee->ctx, shm, offs, false);
> > +       if (rc)
> > +               goto out;
> > +       if (msg_arg->ret != TEEC_SUCCESS) {
> > +               rc = -EINVAL;
> > +               goto out;
> > +       }
> > +
> > +out:
> > +       optee_free_msg_arg(optee->ctx, entry, offs);
> > +       return rc;
> > +}
> > +
> > +static int optee_smc_reclaim_rstmem(struct optee *optee, struct tee_shm *rstmem)
> > +{
> > +       struct optee_shm_arg_entry *entry;
> > +       struct optee_msg_arg *msg_arg;
> > +       struct tee_shm *shm;
> > +       u_int offs;
> > +       int rc;
> > +
> > +       msg_arg = optee_get_msg_arg(optee->ctx, 1, &entry, &shm, &offs);
> > +       if (IS_ERR(msg_arg))
> > +               return PTR_ERR(msg_arg);
> > +
> > +       msg_arg->cmd = OPTEE_MSG_CMD_RECLAIM_RSTMEM;
> > +       msg_arg->params[0].attr = OPTEE_MSG_ATTR_TYPE_RMEM_INPUT;
> > +       msg_arg->params[0].u.rmem.shm_ref = (u_long)rstmem;
> > +
> > +       rc = optee->ops->do_call_with_arg(optee->ctx, shm, offs, false);
> > +       if (rc)
> > +               goto out;
> > +       if (msg_arg->ret != TEEC_SUCCESS)
> > +               rc = -EINVAL;
> > +
> > +out:
> > +       optee_free_msg_arg(optee->ctx, entry, offs);
> > +       return rc;
> > +}
> > +
> >  /*
> >   * 5. Asynchronous notification
> >   */
> > @@ -1201,6 +1262,8 @@ static void optee_get_version(struct tee_device *teedev,
> >                 v.gen_caps |= TEE_GEN_CAP_REG_MEM;
> >         if (optee->smc.sec_caps & OPTEE_SMC_SEC_CAP_MEMREF_NULL)
> >                 v.gen_caps |= TEE_GEN_CAP_MEMREF_NULL;
> > +       if (optee->rstmem_pools)
> > +               v.gen_caps |= TEE_GEN_CAP_RSTMEM;
> >         *vers = v;
> >  }
> >
> > @@ -1223,6 +1286,8 @@ static const struct tee_driver_ops optee_clnt_ops = {
> >         .cancel_req = optee_cancel_req,
> >         .shm_register = optee_shm_register,
> >         .shm_unregister = optee_shm_unregister,
> > +       .rstmem_alloc = optee_rstmem_alloc,
> > +       .rstmem_free = optee_rstmem_free,
> >  };
> >
> >  static const struct tee_desc optee_clnt_desc = {
> > @@ -1239,6 +1304,8 @@ static const struct tee_driver_ops optee_supp_ops = {
> >         .supp_send = optee_supp_send,
> >         .shm_register = optee_shm_register_supp,
> >         .shm_unregister = optee_shm_unregister_supp,
> > +       .rstmem_alloc = optee_rstmem_alloc,
> > +       .rstmem_free = optee_rstmem_free,
> >  };
> >
> >  static const struct tee_desc optee_supp_desc = {
> > @@ -1252,6 +1319,9 @@ static const struct optee_ops optee_ops = {
> >         .do_call_with_arg = optee_smc_do_call_with_arg,
> >         .to_msg_param = optee_to_msg_param,
> >         .from_msg_param = optee_from_msg_param,
> > +       .lend_rstmem = optee_smc_lend_rstmem,
> > +       .reclaim_rstmem = optee_smc_reclaim_rstmem,
> > +       //.alloc_rstmem_pool = optee_smc_alloc_rstmem_pool,
> >  };
> >
> >  static int enable_async_notif(optee_invoke_fn *invoke_fn)
> > @@ -1619,6 +1689,62 @@ static inline int optee_load_fw(struct platform_device *pdev,
> >  }
> >  #endif
> >
> > +static int optee_sdp_pool_init(struct optee *optee)
> > +{
> > +       bool dyn_sdp = optee->smc.sec_caps & OPTEE_SMC_SEC_CAP_DYNAMIC_RSTMEM;
> > +       bool sdp = optee->smc.sec_caps & OPTEE_SMC_SEC_CAP_SDP;
> > +       struct tee_shm_pool *pool;
> > +       int rc;
> > +
> > +       /*
> > +        * optee_sdp_pools_init() must be called if secure world has any
> > +        * SDP capability. If the static carvout is available initialize
> > +        * and add a pool for that. If there's an error from secure world
> > +        * we complain but don't call optee_sdp_pools_uninit() unless we
> > +        * know that there is no SDP capability left.
> > +        */
> > +       if (!dyn_sdp && !sdp)
> > +               return 0;
> > +
> > +       rc = optee_rstmem_pools_init(optee);
> > +       if (rc)
> > +               return rc;
> > +
> > +       if (optee->smc.sec_caps & OPTEE_SMC_SEC_CAP_SDP) {
> > +               union {
> > +                       struct arm_smccc_res smccc;
> > +                       struct optee_smc_get_sdp_config_result result;
> > +               } res;
> > +
> > +               optee->smc.invoke_fn(OPTEE_SMC_GET_SDP_CONFIG, 0, 0, 0, 0, 0, 0,
> > +                                    0, &res.smccc);
> > +               if (res.result.status != OPTEE_SMC_RETURN_OK) {
> > +                       pr_err("Secure Data Path service not available\n");
> > +                       if (!dyn_sdp)
> > +                               goto err;
> > +                       return 0;
> > +               }
> > +
> > +               pool = tee_rstmem_gen_pool_alloc(res.result.start,
> > +                                                res.result.size);
> > +               if (IS_ERR(pool)) {
> > +                       rc = PTR_ERR(pool);
> > +                       goto err;
> > +               }
> > +               rc = xa_insert(&optee->rstmem_pools->xa,
> > +                              TEE_IOC_UC_SECURE_VIDEO_PLAY, pool, GFP_KERNEL);
> > +               if (rc) {
> > +                       pool->ops->destroy_pool(pool);
> > +                       goto err;
> > +               }
> > +       }
> > +
> > +       return 0;
> > +err:
> > +       optee_rstmem_pools_uninit(optee);
> > +       return rc;
> > +}
> > +
> >  static int optee_probe(struct platform_device *pdev)
> >  {
> >         optee_invoke_fn *invoke_fn;
> > @@ -1714,7 +1840,7 @@ static int optee_probe(struct platform_device *pdev)
> >         optee = kzalloc(sizeof(*optee), GFP_KERNEL);
> >         if (!optee) {
> >                 rc = -ENOMEM;
> > -               goto err_free_pool;
> > +               goto err_free_shm_pool;
> >         }
> >
> >         optee->ops = &optee_ops;
> > @@ -1726,10 +1852,14 @@ static int optee_probe(struct platform_device *pdev)
> >             (sec_caps & OPTEE_SMC_SEC_CAP_RPMB_PROBE))
> >                 optee->in_kernel_rpmb_routing = true;
> >
> > +       rc = optee_sdp_pool_init(optee);
> > +       if (rc)
> > +               goto err_free_optee;
> > +
> >         teedev = tee_device_alloc(&optee_clnt_desc, NULL, pool, optee);
> >         if (IS_ERR(teedev)) {
> >                 rc = PTR_ERR(teedev);
> > -               goto err_free_optee;
> > +               goto err_rstmem_pools_uninit;
> >         }
> >         optee->teedev = teedev;
> >
> > @@ -1836,9 +1966,11 @@ static int optee_probe(struct platform_device *pdev)
> >         tee_device_unregister(optee->supp_teedev);
> >  err_unreg_teedev:
> >         tee_device_unregister(optee->teedev);
> > +err_rstmem_pools_uninit:
> > +       optee_rstmem_pools_uninit(optee);
> >  err_free_optee:
> >         kfree(optee);
> > -err_free_pool:
> > +err_free_shm_pool:
> >         tee_shm_pool_free(pool);
> >         if (memremaped_shm)
> >                 memunmap(memremaped_shm);
> > --
> > 2.43.0
> >