[RFT] arm64: dts: qcom: sm8350: Reenable crypto & cryptobam

When num-channels and qcom,num-ees is not provided in devicetree, the
driver will try to read these values from the registers during probe but
this fails if the interconnect is not on and then crashes the system.

So we can provide these properties in devicetree (queried after patching
BAM driver to enable the necessary interconnect) so we can probe
cryptobam without reading registers and then also use the QCE as
expected.

Fixes: 4d29db204361 ("arm64: dts: qcom: sm8350: fix BAM DMA crash and reboot")
Fixes: f1040a7fe8f0 ("arm64: dts: qcom: sm8350: Add Crypto Engine support")
Signed-off-by: Luca Weiss <luca.weiss@fairphone.com>
---
Not tested myself, but David Heidelberg was so nice and ran it on a
SM8350 board in a test farm and it seems to be working as expected.

But still please test it on some other boards so make sure it actually
works as expected there also.
---
 arch/arm64/boot/dts/qcom/sm8350.dtsi | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)


---
base-commit: 0dd3ee31125508cd67f7e7172247f05b7fd1753a
change-id: 20240108-sm8350-qce-6ada49f90657

Best regards,

On Wed Mar 27, 2024 at 10:34 PM CET, Konrad Dybcio wrote:
> On 16.02.2024 11:36 AM, Luca Weiss wrote:
> > On Mon Jan 8, 2024 at 11:45 PM CET, Dmitry Baryshkov wrote:
> >> On Mon, 8 Jan 2024 at 16:23, Luca Weiss <luca.weiss@fairphone.com> wrote:
> >>>
> >>> On Mon Jan 8, 2024 at 3:18 PM CET, Konrad Dybcio wrote:
> >>>> On 8.01.2024 14:49, Luca Weiss wrote:
> >>>>> When num-channels and qcom,num-ees is not provided in devicetree, the
> >>>>> driver will try to read these values from the registers during probe but
> >>>>> this fails if the interconnect is not on and then crashes the system.
> >>>>>
> >>>>> So we can provide these properties in devicetree (queried after patching
> >>>>> BAM driver to enable the necessary interconnect) so we can probe
> >>>>> cryptobam without reading registers and then also use the QCE as
> >>>>> expected.
> >>>>
> >>>> This really feels a bit backwards.. Enable the resource to query the
> >>>> hardware for numbers, so that said resource can be enabled, but
> >>>> slightly later :/
> >>>
> >>> If you think adding interconnect support to driver and dtsi is better,
> >>> let me know.
> >>
> >> I'd say, adding the proper interconnect is a better option. Otherwise
> >> we just depend on the QCE itself to set up the vote for us.
> > 
> > Yes, currently we depend on that.
> > 
> >>
> >>>
> >>> Stephan (+CC) mentioned it should be okay like this *shrug*
> >>>
> >>> For the record, this is the same way I got the values for sc7280[0] and
> >>> sm6350[1].
> >>>
> >>> [0] https://lore.kernel.org/linux-arm-msm/20231229-sc7280-cryptobam-fixup-v1-1-bd8f68589b80@fairphone.com/
> >>> [1] https://lore.kernel.org/linux-arm-msm/20240105-sm6350-qce-v1-0-416e5c7319ac@fairphone.com/
> >>>
> >>> diff --git a/arch/arm64/boot/dts/qcom/sm8350.dtsi b/arch/arm64/boot/dts/qcom/sm8350.dtsi
> >>> index b46236235b7f..cd4dd9852d9e 100644
> >>> --- a/arch/arm64/boot/dts/qcom/sm8350.dtsi
> >>> +++ b/arch/arm64/boot/dts/qcom/sm8350.dtsi
> >>> @@ -1756,8 +1756,8 @@ cryptobam: dma-controller@1dc4000 {
> >>>                         qcom,controlled-remotely;
> >>>                         iommus = <&apps_smmu 0x594 0x0011>,
> >>>                                  <&apps_smmu 0x596 0x0011>;
> >>> -                       /* FIXME: Probing BAM DMA causes some abort and system hang */
> >>> -                       status = "fail";
> >>> +                       interconnects = <&aggre2_noc MASTER_CRYPTO 0 &mc_virt SLAVE_EBI1 0>;
> >>> +                       interconnect-names = "memory";
> >>>                 };
> >>>
> >>>                 crypto: crypto@1dfa000 {
> >>> diff --git a/drivers/dma/qcom/bam_dma.c b/drivers/dma/qcom/bam_dma.c
> >>> index 5e7d332731e0..9de28f615639 100644
> >>> --- a/drivers/dma/qcom/bam_dma.c
> >>> +++ b/drivers/dma/qcom/bam_dma.c
> >>> @@ -40,6 +40,7 @@
> >>>  #include <linux/circ_buf.h>
> >>>  #include <linux/clk.h>
> >>>  #include <linux/dmaengine.h>
> >>> +#include <linux/interconnect.h>
> >>>  #include <linux/pm_runtime.h>
> >>>
> >>>  #include "../dmaengine.h"
> >>> @@ -394,6 +395,7 @@ struct bam_device {
> >>>         const struct reg_offset_data *layout;
> >>>
> >>>         struct clk *bamclk;
> >>> +       struct icc_path *mem_path;
> >>>         int irq;
> >>>
> >>>         /* dma start transaction tasklet */
> >>> @@ -1206,6 +1208,7 @@ static int bam_init(struct bam_device *bdev)
> >>>                 bdev->num_channels = val & BAM_NUM_PIPES_MASK;
> >>>         }
> >>>
> >>> +       printk(KERN_ERR "%s:%d DBG num_ees=%u num_channels=%u\n", __func__, __LINE__, bdev->num_ees, bdev->num_channels);
> >>>         /* Reset BAM now if fully controlled locally */
> >>>         if (!bdev->controlled_remotely && !bdev->powered_remotely)
> >>>                 bam_reset(bdev);
> >>> @@ -1298,6 +1301,14 @@ static int bam_dma_probe(struct platform_device *pdev)
> >>>                 return ret;
> >>>         }
> >>>
> >>> +       bdev->mem_path = devm_of_icc_get(bdev->dev, "memory");
> >>> +       if (IS_ERR(bdev->mem_path))
> >>> +               return PTR_ERR(bdev->mem_path);
> >>> +
> >>> +       ret = icc_set_bw(bdev->mem_path, 1, 1);
> >>
> >> Probably this needs some more sensible value.
> > 
> > So downstream qcedev driver uses 384 for the interconnect. But this is
> > crypto-specific and probably different BAMs have different minimum
> > requirements?
> > 
> > #define CRYPTO_AVG_BW			384
> > #define CRYPTO_PEAK_BW			384
> > https://github.com/xiaomi-sm8450-kernel/android_kernel_platform_msm-kernel/blob/lineage-20/drivers/crypto/msm/qce.h#L57
> > 
> > Do you have any suggestion what to use here?
>
> I'dve expected this to mean anything, but apparently not.
>
> My immediate guess is that the 384 was the lowest magic value that didn't
> result in the bus getting kicked offline.. 1 should be fine upstream due
> to commit 91e045b93db7 ("interconnect: qcom: Fix small BW votes being
> truncated to zero").
>
> > 
> > Also I'd assume that with pm_runtime suspended we'd need to clear the
> > votes in the driver so we don't keep the interconnect alive
> > unnecessarily?
>
> My naive understanding is that the power should only be necessary when
> the thing is in use, so early probe and pm-active sounds about sane..

Bit of a late update on this, going through my inbox again:

I don't think I'll work on implementing interconnect for the BAM driver,
I neither really have the motivation to work on it, nor really any
knowledge on crypto or BAM, or about some details of the hardware.

So feel free to pick this patch to unbreak crypto on sm8350 (adding
num-channels & qcom,num-ees is what's done on many other SoCs as well,
sm8350 wouldn't be an outlier), or we wait for someone to pick up
implementing icc for BAM.

I'll remove this from my inbox now :)

Regards
Luca

>
> Konrad