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References: <20240223095133.109046-1-balint.dobszay@arm.com> <20240223095133.109046-2-balint.dobszay@arm.com>
In-Reply-To: <20240223095133.109046-2-balint.dobszay@arm.com>
From: Sumit Garg <sumit.garg@linaro.org>
Date: Tue, 27 Feb 2024 11:36:47 +0530
Message-ID: <CAFA6WYNW9-7gCZQSEaV=Gcr+GLdu25rQ8MpTg9yNpX7OwyZ0Tg@mail.gmail.com>
Subject: Re: [PATCH v2 1/3] tee: optee: Move pool_op helper functions
To: Balint Dobszay <balint.dobszay@arm.com>
Cc: op-tee@lists.trustedfirmware.org, linux-doc@vger.kernel.org, 
	linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org, 
	jens.wiklander@linaro.org, corbet@lwn.net, sudeep.holla@arm.com, 
	rdunlap@infradead.org, krzk@kernel.org, gyorgy.szing@arm.com
Content-Type: text/plain; charset="UTF-8"

Hi Balint,

On Fri, 23 Feb 2024 at 15:22, Balint Dobszay <balint.dobszay@arm.com> wrote:
>
> Move the pool alloc and free helper functions from the OP-TEE driver to
> the TEE subsystem, since these could be reused in other TEE drivers.
> This patch is not supposed to change behavior, it's only reorganizing
> the code.
>
> Suggested-by: Jens Wiklander <jens.wiklander@linaro.org>
> Signed-off-by: Balint Dobszay <balint.dobszay@arm.com>
> ---
>  drivers/tee/optee/core.c          | 64 ------------------------------
>  drivers/tee/optee/ffa_abi.c       |  6 +--
>  drivers/tee/optee/optee_private.h | 12 ------
>  drivers/tee/optee/smc_abi.c       | 11 +++---
>  drivers/tee/tee_shm.c             | 65 +++++++++++++++++++++++++++++++
>  include/linux/tee_drv.h           | 11 ++++++
>  6 files changed, 85 insertions(+), 84 deletions(-)
>
> diff --git a/drivers/tee/optee/core.c b/drivers/tee/optee/core.c
> index 3aed554bc8d8..9390f21f9902 100644
> --- a/drivers/tee/optee/core.c
> +++ b/drivers/tee/optee/core.c
> @@ -9,7 +9,6 @@
>  #include <linux/crash_dump.h>
>  #include <linux/errno.h>
>  #include <linux/io.h>
> -#include <linux/mm.h>
>  #include <linux/module.h>
>  #include <linux/slab.h>
>  #include <linux/string.h>
> @@ -17,69 +16,6 @@
>  #include <linux/types.h>
>  #include "optee_private.h"
>
> -int optee_pool_op_alloc_helper(struct tee_shm_pool *pool, struct tee_shm *shm,
> -                              size_t size, size_t align,
> -                              int (*shm_register)(struct tee_context *ctx,
> -                                                  struct tee_shm *shm,
> -                                                  struct page **pages,
> -                                                  size_t num_pages,
> -                                                  unsigned long start))
> -{
> -       size_t nr_pages = roundup(size, PAGE_SIZE) / PAGE_SIZE;
> -       struct page **pages;
> -       unsigned int i;
> -       int rc = 0;
> -
> -       /*
> -        * Ignore alignment since this is already going to be page aligned
> -        * and there's no need for any larger alignment.
> -        */
> -       shm->kaddr = alloc_pages_exact(nr_pages * PAGE_SIZE,
> -                                      GFP_KERNEL | __GFP_ZERO);
> -       if (!shm->kaddr)
> -               return -ENOMEM;
> -
> -       shm->paddr = virt_to_phys(shm->kaddr);
> -       shm->size = nr_pages * PAGE_SIZE;
> -
> -       pages = kcalloc(nr_pages, sizeof(*pages), GFP_KERNEL);
> -       if (!pages) {
> -               rc = -ENOMEM;
> -               goto err;
> -       }
> -
> -       for (i = 0; i < nr_pages; i++)
> -               pages[i] = virt_to_page((u8 *)shm->kaddr + i * PAGE_SIZE);
> -
> -       shm->pages = pages;
> -       shm->num_pages = nr_pages;
> -
> -       if (shm_register) {
> -               rc = shm_register(shm->ctx, shm, pages, nr_pages,
> -                                 (unsigned long)shm->kaddr);
> -               if (rc)
> -                       goto err;
> -       }
> -
> -       return 0;
> -err:
> -       free_pages_exact(shm->kaddr, shm->size);
> -       shm->kaddr = NULL;
> -       return rc;
> -}
> -
> -void optee_pool_op_free_helper(struct tee_shm_pool *pool, struct tee_shm *shm,
> -                              int (*shm_unregister)(struct tee_context *ctx,
> -                                                    struct tee_shm *shm))
> -{
> -       if (shm_unregister)
> -               shm_unregister(shm->ctx, shm);
> -       free_pages_exact(shm->kaddr, shm->size);
> -       shm->kaddr = NULL;
> -       kfree(shm->pages);
> -       shm->pages = NULL;
> -}
> -
>  static void optee_bus_scan(struct work_struct *work)
>  {
>         WARN_ON(optee_enumerate_devices(PTA_CMD_GET_DEVICES_SUPP));
> diff --git a/drivers/tee/optee/ffa_abi.c b/drivers/tee/optee/ffa_abi.c
> index ecb5eb079408..ee11918a2b35 100644
> --- a/drivers/tee/optee/ffa_abi.c
> +++ b/drivers/tee/optee/ffa_abi.c
> @@ -374,14 +374,14 @@ static int optee_ffa_shm_unregister_supp(struct tee_context *ctx,
>  static int pool_ffa_op_alloc(struct tee_shm_pool *pool,
>                              struct tee_shm *shm, size_t size, size_t align)
>  {
> -       return optee_pool_op_alloc_helper(pool, shm, size, align,
> -                                         optee_ffa_shm_register);
> +       return tee_shm_pool_op_alloc_helper(pool, shm, size, align,
> +                                           optee_ffa_shm_register);
>  }
>
>  static void pool_ffa_op_free(struct tee_shm_pool *pool,
>                              struct tee_shm *shm)
>  {
> -       optee_pool_op_free_helper(pool, shm, optee_ffa_shm_unregister);
> +       tee_shm_pool_op_free_helper(pool, shm, optee_ffa_shm_unregister);
>  }
>
>  static void pool_ffa_op_destroy_pool(struct tee_shm_pool *pool)
> diff --git a/drivers/tee/optee/optee_private.h b/drivers/tee/optee/optee_private.h
> index 7a5243c78b55..a153285a1919 100644
> --- a/drivers/tee/optee/optee_private.h
> +++ b/drivers/tee/optee/optee_private.h
> @@ -283,18 +283,6 @@ int optee_cancel_req(struct tee_context *ctx, u32 cancel_id, u32 session);
>  int optee_enumerate_devices(u32 func);
>  void optee_unregister_devices(void);
>
> -int optee_pool_op_alloc_helper(struct tee_shm_pool *pool, struct tee_shm *shm,
> -                              size_t size, size_t align,
> -                              int (*shm_register)(struct tee_context *ctx,
> -                                                  struct tee_shm *shm,
> -                                                  struct page **pages,
> -                                                  size_t num_pages,
> -                                                  unsigned long start));
> -void optee_pool_op_free_helper(struct tee_shm_pool *pool, struct tee_shm *shm,
> -                              int (*shm_unregister)(struct tee_context *ctx,
> -                                                    struct tee_shm *shm));
> -
> -
>  void optee_remove_common(struct optee *optee);
>  int optee_open(struct tee_context *ctx, bool cap_memref_null);
>  void optee_release(struct tee_context *ctx);
> diff --git a/drivers/tee/optee/smc_abi.c b/drivers/tee/optee/smc_abi.c
> index a37f87087e5c..b0c616b6870d 100644
> --- a/drivers/tee/optee/smc_abi.c
> +++ b/drivers/tee/optee/smc_abi.c
> @@ -592,19 +592,20 @@ static int pool_op_alloc(struct tee_shm_pool *pool,
>          * to be registered with OP-TEE.
>          */
>         if (shm->flags & TEE_SHM_PRIV)
> -               return optee_pool_op_alloc_helper(pool, shm, size, align, NULL);
> +               return tee_shm_pool_op_alloc_helper(pool, shm, size, align,
> +                                                   NULL);
>
> -       return optee_pool_op_alloc_helper(pool, shm, size, align,
> -                                         optee_shm_register);
> +       return tee_shm_pool_op_alloc_helper(pool, shm, size, align,
> +                                           optee_shm_register);
>  }
>
>  static void pool_op_free(struct tee_shm_pool *pool,
>                          struct tee_shm *shm)
>  {
>         if (!(shm->flags & TEE_SHM_PRIV))
> -               optee_pool_op_free_helper(pool, shm, optee_shm_unregister);
> +               tee_shm_pool_op_free_helper(pool, shm, optee_shm_unregister);
>         else
> -               optee_pool_op_free_helper(pool, shm, NULL);
> +               tee_shm_pool_op_free_helper(pool, shm, NULL);
>  }
>
>  static void pool_op_destroy_pool(struct tee_shm_pool *pool)
> diff --git a/drivers/tee/tee_shm.c b/drivers/tee/tee_shm.c
> index 731d9028b67f..641aad92ffe2 100644
> --- a/drivers/tee/tee_shm.c
> +++ b/drivers/tee/tee_shm.c
> @@ -202,6 +202,71 @@ struct tee_shm *tee_shm_alloc_priv_buf(struct tee_context *ctx, size_t size)
>  }
>  EXPORT_SYMBOL_GPL(tee_shm_alloc_priv_buf);
>
> +int tee_shm_pool_op_alloc_helper(struct tee_shm_pool *pool, struct tee_shm *shm,

I don't see the first argument (struct tee_shm_pool *pool) being used,
so drop that. Also, we can just rename it as
tee_dyn_shm_alloc_helper().

> +                                size_t size, size_t align,
> +                                int (*shm_register)(struct tee_context *ctx,
> +                                                    struct tee_shm *shm,
> +                                                    struct page **pages,
> +                                                    size_t num_pages,
> +                                                    unsigned long start))
> +{
> +       size_t nr_pages = roundup(size, PAGE_SIZE) / PAGE_SIZE;
> +       struct page **pages;
> +       unsigned int i;
> +       int rc = 0;
> +
> +       /*
> +        * Ignore alignment since this is already going to be page aligned
> +        * and there's no need for any larger alignment.
> +        */
> +       shm->kaddr = alloc_pages_exact(nr_pages * PAGE_SIZE,
> +                                      GFP_KERNEL | __GFP_ZERO);
> +       if (!shm->kaddr)
> +               return -ENOMEM;
> +
> +       shm->paddr = virt_to_phys(shm->kaddr);
> +       shm->size = nr_pages * PAGE_SIZE;
> +
> +       pages = kcalloc(nr_pages, sizeof(*pages), GFP_KERNEL);
> +       if (!pages) {
> +               rc = -ENOMEM;
> +               goto err;
> +       }
> +
> +       for (i = 0; i < nr_pages; i++)
> +               pages[i] = virt_to_page((u8 *)shm->kaddr + i * PAGE_SIZE);
> +
> +       shm->pages = pages;
> +       shm->num_pages = nr_pages;
> +
> +       if (shm_register) {
> +               rc = shm_register(shm->ctx, shm, pages, nr_pages,
> +                                 (unsigned long)shm->kaddr);
> +               if (rc)
> +                       goto err;
> +       }
> +
> +       return 0;
> +err:
> +       free_pages_exact(shm->kaddr, shm->size);
> +       shm->kaddr = NULL;
> +       return rc;
> +}
> +EXPORT_SYMBOL_GPL(tee_shm_pool_op_alloc_helper);
> +
> +void tee_shm_pool_op_free_helper(struct tee_shm_pool *pool, struct tee_shm *shm,

Ditto tee_shm_pool_op_free_helper() -> tee_dyn_shm_free_helper()

> +                                int (*shm_unregister)(struct tee_context *ctx,
> +                                                      struct tee_shm *shm))
> +{
> +       if (shm_unregister)
> +               shm_unregister(shm->ctx, shm);
> +       free_pages_exact(shm->kaddr, shm->size);
> +       shm->kaddr = NULL;
> +       kfree(shm->pages);
> +       shm->pages = NULL;
> +}
> +EXPORT_SYMBOL_GPL(tee_shm_pool_op_free_helper);
> +
>  static struct tee_shm *
>  register_shm_helper(struct tee_context *ctx, struct iov_iter *iter, u32 flags,
>                     int id)
> diff --git a/include/linux/tee_drv.h b/include/linux/tee_drv.h
> index 911ddf92dcee..4cf402424e71 100644
> --- a/include/linux/tee_drv.h
> +++ b/include/linux/tee_drv.h
> @@ -275,6 +275,17 @@ void *tee_get_drvdata(struct tee_device *teedev);
>  struct tee_shm *tee_shm_alloc_priv_buf(struct tee_context *ctx, size_t size);
>  struct tee_shm *tee_shm_alloc_kernel_buf(struct tee_context *ctx, size_t size);
>
> +int tee_shm_pool_op_alloc_helper(struct tee_shm_pool *pool, struct tee_shm *shm,
> +                                size_t size, size_t align,
> +                                int (*shm_register)(struct tee_context *ctx,
> +                                                    struct tee_shm *shm,
> +                                                    struct page **pages,
> +                                                    size_t num_pages,
> +                                                    unsigned long start));
> +void tee_shm_pool_op_free_helper(struct tee_shm_pool *pool, struct tee_shm *shm,
> +                                int (*shm_unregister)(struct tee_context *ctx,
> +                                                      struct tee_shm *shm));
> +

These rather belong to drivers/tee/tee_private.h as we shouldn't
expose them to other kernel client drivers.

-Sumit

>  struct tee_shm *tee_shm_register_kernel_buf(struct tee_context *ctx,
>                                             void *addr, size_t length);
>
> --
> 2.34.1
>