Re: [PATCH v3 8/9] drm/tegra: vic: Implement get_streamid_offset

[Mikko Perttunen <cyndis@kapsi.fi>]

On 2/21/22 19:27, Robin Murphy wrote:
> On 2022-02-18 11:39, Mikko Perttunen via iommu wrote:
>> Implement the get_streamid_offset required for supporting context
>> isolation. Since old firmware cannot support context isolation
>> without hacks that we don't want to implement, check the firmware
>> binary to see if context isolation should be enabled.
>>
>> Signed-off-by: Mikko Perttunen <mperttunen@nvidia.com>
>> ---
>>   drivers/gpu/drm/tegra/vic.c | 38 +++++++++++++++++++++++++++++++++++++
>>   1 file changed, 38 insertions(+)
>>
>> diff --git a/drivers/gpu/drm/tegra/vic.c b/drivers/gpu/drm/tegra/vic.c
>> index 1e342fa3d27b..2863ee5e0e67 100644
>> --- a/drivers/gpu/drm/tegra/vic.c
>> +++ b/drivers/gpu/drm/tegra/vic.c
>> @@ -38,6 +38,8 @@ struct vic {
>>       struct clk *clk;
>>       struct reset_control *rst;
>> +    bool can_use_context;
>> +
>>       /* Platform configuration */
>>       const struct vic_config *config;
>>   };
>> @@ -229,6 +231,7 @@ static int vic_load_firmware(struct vic *vic)
>>   {
>>       struct host1x_client *client = &vic->client.base;
>>       struct tegra_drm *tegra = vic->client.drm;
>> +    u32 fce_bin_data_offset;
>>       dma_addr_t iova;
>>       size_t size;
>>       void *virt;
>> @@ -277,6 +280,25 @@ static int vic_load_firmware(struct vic *vic)
>>           vic->falcon.firmware.phys = phys;
>>       }
>> +    /*
>> +     * Check if firmware is new enough to not require mapping firmware
>> +     * to data buffer domains.
>> +     */
>> +    fce_bin_data_offset = *(u32 *)(virt + VIC_UCODE_FCE_DATA_OFFSET);
>> +
>> +    if (!vic->config->supports_sid) {
>> +        vic->can_use_context = false;
>> +    } else if (fce_bin_data_offset != 0x0 && fce_bin_data_offset != 
>> 0xa5a5a5a5) {
>> +        /*
>> +         * Firmware will access FCE through STREAMID0, so context
>> +         * isolation cannot be used.
>> +         */
>> +        vic->can_use_context = false;
>> +        dev_warn_once(vic->dev, "context isolation disabled due to 
>> old firmware\n");
>> +    } else {
>> +        vic->can_use_context = true;
>> +    }
>> +
>>       return 0;
>>   cleanup:
>> @@ -358,10 +380,26 @@ static void vic_close_channel(struct 
>> tegra_drm_context *context)
>>       host1x_channel_put(context->channel);
>>   }
>> +static int vic_get_streamid_offset(struct tegra_drm_client *client)
>> +{
>> +    struct vic *vic = to_vic(client);
>> +    int err;
>> +
>> +    err = vic_load_firmware(vic);
>> +    if (err < 0)
>> +        return err;
>> +
>> +    if (vic->can_use_context)
>> +        return 0x30;
>> +    else
>> +        return -ENOTSUPP;
>> +}
>> +
>>   static const struct tegra_drm_client_ops vic_ops = {
>>       .open_channel = vic_open_channel,
>>       .close_channel = vic_close_channel,
>>       .submit = tegra_drm_submit,
>> +    .get_streamid_offset = vic_get_streamid_offset,
> 
> The patch order seems off here, since the .get_streamid_offset member 
> isn't defined yet.
> 
> Robin.

Indeed, will fix.

Thanks,
Mikko

> 
>>   };
>>   #define NVIDIA_TEGRA_124_VIC_FIRMWARE "nvidia/tegra124/vic03_ucode.bin"