On 10.12.19 08:56, Horia Geanta wrote:
> On 12/6/2019 9:55 PM, Adam Ford wrote:
>> On Wed, Dec 4, 2019 at 5:38 AM Schrempf Frieder
>> <frieder.schrempf@xxxxxxxxxx> wrote:
>>>
>>> Hi Adam,
>>>
>>> On 30.11.19 23:51, Adam Ford wrote:
>>>> The i.MX8M Mini uses the same crypto engine as the i.MX8MQ, but
>>>> the driver is restricting the check to just the i.MX8MQ.
>>>>
>>>> This patch lets the driver support all i.MX8M Variants if enabled.
>>>>
>>>> Signed-off-by: Adam Ford <aford173@xxxxxxxxx>
>>>
>>> What about the following lines in run_descriptor_deco0()? Does this
>>> condition also apply to i.MX8MM?
>>
>> I think that's a question for NXP. I am not seeing that in the NXP
>> Linux Release, and I don't have an 8MQ to compare.
>>
> IIRC the i.MX BSP releases use the JRI for initializing the RNG,
> and not the DECO register interface.
>
>> I was able to get the driver working on the i.MXMM with the patch.
>>
> You are probably using a newer U-boot, which includes
> commit dfaec76029f2 ("crypto/fsl: instantiate all rng state handles")
>
>> NXP Team,
>>
>> Do you have any opinions on this?
>>
> Since current U-boot initializes both RNG state handles, practically
> instantiate_rng() is a no-op.
>
> A simple experiment is to "lie" about the state_handle_mask, to exercise
> the DECO acquire code (or, as mentioned above, to run with an older U-boot):
>
> @@ -268,12 +272,19 @@ static int instantiate_rng(struct device *ctrldev, int state_handle_mask,
> struct caam_ctrl __iomem *ctrl;
> u32 *desc, status = 0, rdsta_val;
> int ret = 0, sh_idx;
> + static int force_init = 1;
>
> ctrl = (struct caam_ctrl __iomem *)ctrlpriv->ctrl;
> desc = kmalloc(CAAM_CMD_SZ * 7, GFP_KERNEL);
> if (!desc)
> return -ENOMEM;
>
> + if (force_init && (state_handle_mask == 0x3)) {
> + dev_err(ctrldev, "Forcing reinit of RNG state handle 0!\n");
> + force_init = 0;
> + state_handle_mask = 0x2;
> + }
> +
> for (sh_idx = 0; sh_idx < RNG4_MAX_HANDLES; sh_idx++) {
> /*
> * If the corresponding bit is set, this state handle
>
> In this case boot log confirms the DECO cannot be acquired:
> [ 2.137101] caam 30900000.crypto: Forcing reinit of RNG state handle 0!
> [ 2.172293] caam 30900000.crypto: failed to acquire DECO 0
> [ 2.177786] caam 30900000.crypto: failed to instantiate RNG
>
> To sum up, writing to DECORSR is mandatory.
Thanks Horia for providing the details.
Adam, can you update your patch to enable the code in
run_descriptor_deco0() for i.MX8MM?
If I understand this correctly, this is necessary to have the RNG
initialize correctly no matter what version of U-Boot is used.
Thanks,
Frieder
