linux-kernel - Re: [PATCH] drm/shmem: drop pgprot

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Message-ID: <997a1baa-dc71-47d3-6e93-4dc953844d68@shipmail.org>
Date:   Fri, 28 Feb 2020 12:15:43 +0100
From:   Thomas Hellström (VMware) 
        <thomas_os@...pmail.org>
To:     Gerd Hoffmann <kraxel@...hat.com>, dri-devel@...ts.freedesktop.org
Cc:     David Airlie <airlied@...ux.ie>,
        open list <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH] drm/shmem: drop pgprot_decrypted()

On 2/28/20 11:47 AM, Gerd Hoffmann wrote:
> Was added by commit 95cf9264d5f3 ("x86, drm, fbdev: Do not specify
> encrypted memory for video mappings"), then it was kept through various
> changes.
>
> While vram actually needs decrypted mappings this is not correct for
> shmem gem objects which live in main memory not io memory, so remove the
> call.
>
> Signed-off-by: Gerd Hoffmann <kraxel@...hat.com>
> ---
>   drivers/gpu/drm/drm_gem_shmem_helper.c | 1 -
>   1 file changed, 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/drm_gem_shmem_helper.c b/drivers/gpu/drm/drm_gem_shmem_helper.c
> index aad9324dcf4f..df31e5782eed 100644
> --- a/drivers/gpu/drm/drm_gem_shmem_helper.c
> +++ b/drivers/gpu/drm/drm_gem_shmem_helper.c
> @@ -548,7 +548,6 @@ int drm_gem_shmem_mmap(struct drm_gem_object *obj, struct vm_area_struct *vma)
>   	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;
>   
>   	return 0;

Reviewed-by: Thomas Hellstrom <thellstrom@...are.com>

Thanks,

Thomas