Reply-To: christian.koenig@amd.com
Subject: Re: [PATCH 01/12] drm/ttm: Use ttm_bo_default_io_mem_pfn if
 io_mem_pfn is NULL
To: Tan Xiaojun <tanxiaojun@huawei.com>, seanpaul@chromium.org,
        christian.koenig@amd.com, airlied@linux.ie, michel.daenzer@amd.com,
        alexander.deucher@amd.com, nicolai.haehnle@amd.com,
        thomas.lendacky@amd.com, yamada.masahiro@socionext.com, msrb@suse.com,
        Felix.Kuehling@amd.com, dave.jiang@intel.com,
        gregkh@linuxfoundation.org, michael.thayer@oracle.com,
        hdegoede@redhat.com
Cc: daniel.vetter@intel.com, dri-devel@lists.freedesktop.org,
        linux-kernel@vger.kernel.org
References: <1514096068-80414-1-git-send-email-tanxiaojun@huawei.com>
 <1514096068-80414-2-git-send-email-tanxiaojun@huawei.com>
From: =?UTF-8?Q?Christian_K=c3=b6nig?= <ckoenig.leichtzumerken@gmail.com>
Message-ID: <7542197c-a821-a5d2-1abd-449c823c53e5@gmail.com>
Date: Sun, 24 Dec 2017 10:27:02 +0100
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Am 24.12.2017 um 07:14 schrieb Tan Xiaojun:
> From: Michal Srb <msrb@suse.com>
>
> The io_mem_pfn field was added in commit ea642c3216cb2a60d1c0e760ae47ee85c9c16447
> and is called unconditionally. However, not all drivers were updated to set it.
>
> Use the ttm_bo_default_io_mem_pfn function if a driver did not set its own.
>
> Signed-off-by: Michal Srb <msrb@suse.com>
> ---
>   drivers/gpu/drm/ttm/ttm_bo_vm.c | 5 ++++-
>   1 file changed, 4 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/gpu/drm/ttm/ttm_bo_vm.c b/drivers/gpu/drm/ttm/ttm_bo_vm.c
> index c8ebb75..e25a99b 100644
> --- a/drivers/gpu/drm/ttm/ttm_bo_vm.c
> +++ b/drivers/gpu/drm/ttm/ttm_bo_vm.c
> @@ -234,7 +234,10 @@ static int ttm_bo_vm_fault(struct vm_fault *vmf)
>   		if (bo->mem.bus.is_iomem) {
>   			/* Iomem should not be marked encrypted */
>   			cvma.vm_page_prot = pgprot_decrypted(cvma.vm_page_prot);
> -			pfn = bdev->driver->io_mem_pfn(bo, page_offset);
> +			if (bdev->driver->io_mem_pfn)
> +				pfn = bdev->driver->io_mem_pfn(bo, page_offset);
> +			else
> +				pfn = ttm_bo_default_io_mem_pfn(bo, page_offset);

Please move this check into a new function ttm_bo_io_mem_pfn().

You can then move the calculation of ttm_bo_default_io_mem_pfn() into 
this new function in patch #12 as well.

Regards,
Christian.

>   		} else {
>   			page = ttm->pages[page_offset];
>   			if (unlikely(!page && i == 0)) {