linux-kernel - RE: [PATCH v5 1/3] drm/shmem: add support for per object caching flags.

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <VI1PR0802MB2237D75512DA7A60A272586883EA0@VI1PR0802MB2237.eurprd08.prod.outlook.com>
Date:   Wed, 26 Feb 2020 16:51:36 +0000
From:   Guillaume Gardet <Guillaume.Gardet@....com>
To:     Gerd Hoffmann <kraxel@...hat.com>,
        "dri-devel@...ts.freedesktop.org" <dri-devel@...ts.freedesktop.org>
CC:     "tzimmermann@...e.de" <tzimmermann@...e.de>,
        "gurchetansingh@...omium.org" <gurchetansingh@...omium.org>,
        "olvaffe@...il.com" <olvaffe@...il.com>,
        "stable@...r.kernel.org" <stable@...r.kernel.org>,
        Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
        Maxime Ripard <mripard@...nel.org>,
        David Airlie <airlied@...ux.ie>,
        Daniel Vetter <daniel@...ll.ch>,
        open list <linux-kernel@...r.kernel.org>
Subject: RE: [PATCH v5 1/3] drm/shmem: add support for per object caching
 flags.



> -----Original Message-----
> From: Gerd Hoffmann <kraxel@...hat.com>
> Sent: 26 February 2020 16:48
> To: dri-devel@...ts.freedesktop.org
> Cc: tzimmermann@...e.de; gurchetansingh@...omium.org; olvaffe@...il.com;
> Guillaume Gardet <Guillaume.Gardet@....com>; Gerd Hoffmann
> <kraxel@...hat.com>; stable@...r.kernel.org; Maarten Lankhorst
> <maarten.lankhorst@...ux.intel.com>; Maxime Ripard <mripard@...nel.org>;
> David Airlie <airlied@...ux.ie>; Daniel Vetter <daniel@...ll.ch>; open list <linux-
> kernel@...r.kernel.org>
> Subject: [PATCH v5 1/3] drm/shmem: add support for per object caching flags.
>
> Add map_cached bool to drm_gem_shmem_object, to request cached mappings
> on a per-object base.  Check the flag before adding writecombine to pgprot bits.
>
> Cc: stable@...r.kernel.org
> Signed-off-by: Gerd Hoffmann <kraxel@...hat.com>

Tested-by: Guillaume Gardet <Guillaume.Gardet@....com>

> ---
>  include/drm/drm_gem_shmem_helper.h     |  5 +++++
>  drivers/gpu/drm/drm_gem_shmem_helper.c | 15 +++++++++++----
>  2 files changed, 16 insertions(+), 4 deletions(-)
>
> diff --git a/include/drm/drm_gem_shmem_helper.h
> b/include/drm/drm_gem_shmem_helper.h
> index e34a7b7f848a..294b2931c4cc 100644
> --- a/include/drm/drm_gem_shmem_helper.h
> +++ b/include/drm/drm_gem_shmem_helper.h
> @@ -96,6 +96,11 @@ struct drm_gem_shmem_object {
>   * The address are un-mapped when the count reaches zero.
>   */
>  unsigned int vmap_use_count;
> +
> +/**
> + * @map_cached: map object cached (instead of using writecombine).
> + */
> +bool map_cached;
>  };
>
>  #define to_drm_gem_shmem_obj(obj) \
> diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c
> b/drivers/gpu/drm/drm_gem_shmem_helper.c
> index a421a2eed48a..aad9324dcf4f 100644
> --- a/drivers/gpu/drm/drm_gem_shmem_helper.c
> +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
> @@ -254,11 +254,16 @@ static void *drm_gem_shmem_vmap_locked(struct
> drm_gem_shmem_object *shmem)
>  if (ret)
>  goto err_zero_use;
>
> -if (obj->import_attach)
> +if (obj->import_attach) {
>  shmem->vaddr = dma_buf_vmap(obj->import_attach->dmabuf);
> -else
> +} else {
> +pgprot_t prot = PAGE_KERNEL;
> +
> +if (!shmem->map_cached)
> +prot = pgprot_writecombine(prot);
>  shmem->vaddr = vmap(shmem->pages, obj->size >>
> PAGE_SHIFT,
> -    VM_MAP,
> pgprot_writecombine(PAGE_KERNEL));
> +    VM_MAP, prot);
> +}
>
>  if (!shmem->vaddr) {
>  DRM_DEBUG_KMS("Failed to vmap pages\n"); @@ -540,7 +545,9
> @@ int drm_gem_shmem_mmap(struct drm_gem_object *obj, struct
> vm_area_struct *vma)
>  }
>
>  vma->vm_flags |= VM_MIXEDMAP | VM_DONTEXPAND;
> -vma->vm_page_prot = pgprot_writecombine(vm_get_page_prot(vma-
> >vm_flags));
> +vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
> +if (!shmem->map_cached)
> +vma->vm_page_prot = pgprot_writecombine(vma-
> >vm_page_prot);
>  vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
>  vma->vm_ops = &drm_gem_shmem_vm_ops;
>
> --
> 2.18.2

IMPORTANT NOTICE: The contents of this email and any attachments are confidential and may also be privileged. If you are not the intended recipient, please notify the sender immediately and do not disclose the contents to any other person, use it for any purpose, or store or copy the information in any medium. Thank you.