Re: [PATCH v6 09/10] optee: FF-A: dynamic restricted memory allocation

Jens Wiklander
2025-03-27T08:07:47Z

Hi Sumit,

On Tue, Mar 25, 2025 at 8:42 AM Sumit Garg <sumit.garg@kernel.org> wrote:
>
> On Wed, Mar 05, 2025 at 02:04:15PM +0100, Jens Wiklander wrote:
> > Add support in the OP-TEE backend driver dynamic restricted memory
> > allocation with FF-A.
> >
> > 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.
> >
> > Restricted memory pools based on a static carveout or dynamic allocation
> > can coexist for different use-cases. We use only dynamic allocation with
> > FF-A.
> >
> > Signed-off-by: Jens Wiklander <jens.wiklander@linaro.org>
> > ---
> > drivers/tee/optee/Makefile | 1 +
> > drivers/tee/optee/ffa_abi.c | 143 ++++++++++++-
> > drivers/tee/optee/optee_private.h | 13 +-
> > drivers/tee/optee/rstmem.c | 329 ++++++++++++++++++++++++++++++
> > 4 files changed, 483 insertions(+), 3 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/ffa_abi.c b/drivers/tee/optee/ffa_abi.c
> > index e4b08cd195f3..6a55114232ef 100644
> > --- a/drivers/tee/optee/ffa_abi.c
> > +++ b/drivers/tee/optee/ffa_abi.c
> > @@ -672,6 +672,123 @@ 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,
> > + u32 use_case)
> > +{
> > + 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 = 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, 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
> > *
> > @@ -833,6 +950,8 @@ 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)
> > @@ -941,7 +1060,7 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
> > optee->pool, optee);
> > if (IS_ERR(teedev)) {
> > rc = PTR_ERR(teedev);
> > - goto err_free_pool;
> > + goto err_free_shm_pool;
> > }
> > optee->teedev = teedev;
> >
> > @@ -988,6 +1107,24 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
> > rc);
> > }
> >
> > + if (IS_ENABLED(CONFIG_CMA) && !IS_MODULE(CONFIG_OPTEE) &&
>
> The CMA dependency should be managed via Kconfig.

Yes, I'll fix it.

>
> > + (sec_caps & OPTEE_FFA_SEC_CAP_RSTMEM)) {
> > + enum tee_dma_heap_id id = TEE_DMA_HEAP_SECURE_VIDEO_PLAY;
> > + struct tee_rstmem_pool *pool;
> > +
> > + pool = optee_rstmem_alloc_cma_pool(optee, id);
> > + if (IS_ERR(pool)) {
> > + rc = PTR_ERR(pool);
> > + goto err_notif_uninit;
> > + }
> > +
> > + rc = tee_device_register_dma_heap(optee->teedev, id, pool);
> > + if (rc) {
> > + pool->ops->destroy_pool(pool);
> > + goto err_notif_uninit;
> > + }
> > + }
> > +
> > rc = optee_enumerate_devices(PTA_CMD_GET_DEVICES);
> > if (rc)
> > goto err_unregister_devices;
> > @@ -1001,6 +1138,8 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
> >
> > err_unregister_devices:
> > optee_unregister_devices();
> > + tee_device_unregister_all_dma_heaps(optee->teedev);
> > +err_notif_uninit:
> > if (optee->ffa.bottom_half_value != U32_MAX)
> > notif_ops->notify_relinquish(ffa_dev,
> > optee->ffa.bottom_half_value);
> > @@ -1018,7 +1157,7 @@ static int optee_ffa_probe(struct ffa_device *ffa_dev)
> > tee_device_unregister(optee->supp_teedev);
> > err_unreg_teedev:
> > tee_device_unregister(optee->teedev);
> > -err_free_pool:
> > +err_free_shm_pool:
> > tee_shm_pool_free(pool);
> > err_free_optee:
> > kfree(optee);
> > diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h
> > index 20eda508dbac..faab31ad7c52 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 +196,10 @@ 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,
> > + u32 use_case);
> > + int (*reclaim_rstmem)(struct optee *optee, struct tee_shm *rstmem);
> > };
> >
> > /**
> > @@ -285,6 +294,8 @@ u32 optee_supp_thrd_req(struct tee_context *ctx, u32 func, size_t num_params,
> > void optee_supp_init(struct optee_supp *supp);
> > void optee_supp_uninit(struct optee_supp *supp);
> > void optee_supp_release(struct optee_supp *supp);
> > +struct tee_rstmem_pool *optee_rstmem_alloc_cma_pool(struct optee *optee,
> > + enum tee_dma_heap_id id);
> >
> > int optee_supp_recv(struct tee_context *ctx, u32 *func, u32 *num_params,
> > struct tee_param *param);
> > diff --git a/drivers/tee/optee/rstmem.c b/drivers/tee/optee/rstmem.c
> > new file mode 100644
> > index 000000000000..ea27769934d4
> > --- /dev/null
> > +++ b/drivers/tee/optee/rstmem.c
> > @@ -0,0 +1,329 @@
> > +// SPDX-License-Identifier: GPL-2.0-only
> > +/*
> > + * Copyright (c) 2025, Linaro Limited
> > + */
> > +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
> > +
> > +#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_rstmem_pool pool;
> > + struct gen_pool *gen_pool;
> > + struct optee *optee;
> > + size_t page_count;
> > + u16 *end_points;
> > + u_int end_point_count;
> > + u_int align;
> > + refcount_t refcount;
> > + u32 use_case;
> > + 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_rstmem_pool *pool)
> > +{
> > + return container_of(pool, struct optee_rstmem_cma_pool, pool);
> > +}
> > +
> > +static int init_cma_rstmem(struct optee_rstmem_cma_pool *rp)
> > +{
> > + int rc;
> > +
> > + rp->rstmem = tee_shm_alloc_cma_phys_mem(rp->optee->ctx, rp->page_count,
> > + rp->align);
> > + if (IS_ERR(rp->rstmem)) {
> > + rc = PTR_ERR(rp->rstmem);
> > + goto err_null_rstmem;
> > + }
> > +
> > + /*
> > + * TODO unmap the memory range since the physical memory will
> > + * become inaccesible after the lend_rstmem() call.
> > + */
>
> What's your plan for this TODO? I think we need a CMA allocator here
> which can allocate un-mapped memory such that any cache speculation
> won't lead to CPU hangs once the memory restriction comes into picture.

What happens is platform-specific. For some platforms, it might be
enough to avoid explicit access. Yes, a CMA allocator with unmapped
memory or where memory can be unmapped is one option.

>
> > + rc = rp->optee->ops->lend_rstmem(rp->optee, rp->rstmem, rp->end_points,
> > + rp->end_point_count, rp->use_case);
> > + if (rc)
> > + goto err_put_shm;
> > + rp->rstmem->flags |= TEE_SHM_DYNAMIC;
> > +
> > + rp->gen_pool = gen_pool_create(PAGE_SHIFT, -1);
> > + if (!rp->gen_pool) {
> > + rc = -ENOMEM;
> > + goto err_reclaim;
> > + }
> > +
> > + rc = gen_pool_add(rp->gen_pool, 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->gen_pool);
> > + rp->gen_pool = NULL;
> > +err_reclaim:
> > + rp->optee->ops->reclaim_rstmem(rp->optee, rp->rstmem);
> > +err_put_shm:
> > + tee_shm_put(rp->rstmem);
> > +err_null_rstmem:
> > + rp->rstmem = NULL;
> > + 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->gen_pool) {
> > + /*
> > + * 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->gen_pool);
> > + rp->gen_pool = NULL;
> > +
> > + rp->optee->ops->reclaim_rstmem(rp->optee, rp->rstmem);
> > + rp->rstmem->flags &= ~TEE_SHM_DYNAMIC;
> > +
> > + WARN(refcount_read(&rp->rstmem->refcount) != 1, "Unexpected refcount");
> > + tee_shm_put(rp->rstmem);
> > + rp->rstmem = NULL;
> > +}
> > +
> > +static void put_cma_rstmem(struct optee_rstmem_cma_pool *rp)
> > +{
> > + if (refcount_dec_and_test(&rp->refcount)) {
> > + mutex_lock(&rp->mutex);
> > + if (rp->gen_pool)
> > + release_cma_rstmem(rp);
> > + mutex_unlock(&rp->mutex);
> > + }
> > +}
> > +
> > +static int rstmem_pool_op_cma_alloc(struct tee_rstmem_pool *pool,
> > + struct sg_table *sgt, size_t size,
> > + size_t *offs)
> > +{
> > + 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->gen_pool, sz);
> > + if (!pa) {
> > + rc = -ENOMEM;
> > + goto err_put;
> > + }
> > +
> > + rc = sg_alloc_table(sgt, 1, GFP_KERNEL);
> > + if (rc)
> > + goto err_free;
> > +
> > + sg_set_page(sgt->sgl, phys_to_page(pa), size, 0);
> > + *offs = pa - rp->rstmem->paddr;
> > +
> > + return 0;
> > +err_free:
> > + gen_pool_free(rp->gen_pool, pa, size);
> > +err_put:
> > + put_cma_rstmem(rp);
> > +
> > + return rc;
> > +}
> > +
> > +static void rstmem_pool_op_cma_free(struct tee_rstmem_pool *pool,
> > + struct sg_table *sgt)
> > +{
> > + struct optee_rstmem_cma_pool *rp = to_rstmem_cma_pool(pool);
> > + struct scatterlist *sg;
> > + int i;
> > +
> > + for_each_sgtable_sg(sgt, sg, i)
> > + gen_pool_free(rp->gen_pool, sg_phys(sg), sg->length);
> > + sg_free_table(sgt);
> > + put_cma_rstmem(rp);
> > +}
> > +
> > +static int rstmem_pool_op_cma_update_shm(struct tee_rstmem_pool *pool,
> > + struct sg_table *sgt, size_t offs,
> > + struct tee_shm *shm,
> > + struct tee_shm **parent_shm)
> > +{
> > + struct optee_rstmem_cma_pool *rp = to_rstmem_cma_pool(pool);
> > +
> > + *parent_shm = rp->rstmem;
> > +
> > + return 0;
> > +}
> > +
> > +static void pool_op_cma_destroy_pool(struct tee_rstmem_pool *pool)
> > +{
> > + struct optee_rstmem_cma_pool *rp = to_rstmem_cma_pool(pool);
> > +
> > + mutex_destroy(&rp->mutex);
> > + kfree(rp);
> > +}
> > +
> > +static struct tee_rstmem_pool_ops rstmem_pool_ops_cma = {
> > + .alloc = rstmem_pool_op_cma_alloc,
> > + .free = rstmem_pool_op_cma_free,
> > + .update_shm = rstmem_pool_op_cma_update_shm,
> > + .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)
>
> I guess this end points terminology is specific to FF-A ABI. Is there
> any relevance for this in the common APIs?

Yes, endpoints are specific to FF-A ABI. The list of end-points must
be presented to FFA_MEM_LEND. We're relying on the secure world to
know which endpoints are needed for a specific use case.

Cheers,
Jens

>
> -Sumit
>
> > +{
> > + 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;
> > +}
> > +
> > +struct tee_rstmem_pool *optee_rstmem_alloc_cma_pool(struct optee *optee,
> > + enum tee_dma_heap_id id)
> > +{
> > + struct optee_rstmem_cma_pool *rp;
> > + u32 use_case = id;
> > + size_t min_size;
> > + int rc;
> > +
> > + rp = kzalloc(sizeof(*rp), GFP_KERNEL);
> > + if (!rp)
> > + return ERR_PTR(-ENOMEM);
> > + rp->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);
> > +}
> > --
> > 2.43.0
> >