Re: [Freedreno] [PATCH] drm/msm/dpu: re-introduce dpu core revision to the catalog

From: Dmitry Baryshkov
Date: Tue Jun 06 2023 - 17:08:28 EST


On 07/06/2023 00:01, Dmitry Baryshkov wrote:
On 06/06/2023 22:28, Abhinav Kumar wrote:


On 6/6/2023 12:09 PM, Dmitry Baryshkov wrote:
On 06/06/2023 20:51, Abhinav Kumar wrote:


On 6/6/2023 4:14 AM, Dmitry Baryshkov wrote:
On Tue, 6 Jun 2023 at 05:35, Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx> wrote:



On 6/5/2023 6:03 PM, Dmitry Baryshkov wrote:
On 06/06/2023 03:55, Abhinav Kumar wrote:


On 6/3/2023 7:21 PM, Dmitry Baryshkov wrote:
On 31/05/2023 21:25, Abhinav Kumar wrote:


On 5/31/2023 3:07 AM, Dmitry Baryshkov wrote:
On 31/05/2023 06:05, Abhinav Kumar wrote:


On 5/30/2023 7:53 PM, Dmitry Baryshkov wrote:
On Wed, 31 May 2023 at 03:54, Abhinav Kumar
<quic_abhinavk@xxxxxxxxxxx> wrote:

With [1] dpu core revision was dropped in favor of using the
compatible string from the device tree to select the dpu catalog
being used in the device.

This approach works well however also necessitates adding catalog
entries for small register level details as dpu capabilities and/or
features bloating the catalog unnecessarily. Examples include but
are not limited to data_compress, interrupt register set,
widebus etc.

Introduce the dpu core revision back as an entry to the catalog
so that
we can just use dpu revision checks and enable those bits which
should be enabled unconditionally and not controlled by a catalog
and also simplify the changes to do something like:

if (dpu_core_revision > xxxxx && dpu_core_revision < xxxxx)
          enable the bit;

Also, add some of the useful macros back to be able to use dpu core
revision effectively.

[1]:
https://patchwork.freedesktop.org/patch/530891/?series=113910&rev=4

Signed-off-by: Abhinav Kumar <quic_abhinavk@xxxxxxxxxxx>
---
   .../msm/disp/dpu1/catalog/dpu_3_0_msm8998.h   |  1 +
   .../msm/disp/dpu1/catalog/dpu_4_0_sdm845.h    |  1 +
   .../msm/disp/dpu1/catalog/dpu_5_0_sm8150.h    |  1 +
   .../msm/disp/dpu1/catalog/dpu_5_1_sc8180x.h   |  1 +
   .../msm/disp/dpu1/catalog/dpu_6_0_sm8250.h    |  1 +
   .../msm/disp/dpu1/catalog/dpu_6_2_sc7180.h    |  1 +
   .../msm/disp/dpu1/catalog/dpu_6_3_sm6115.h    |  1 +
   .../msm/disp/dpu1/catalog/dpu_6_5_qcm2290.h   |  1 +
   .../msm/disp/dpu1/catalog/dpu_7_0_sm8350.h    |  1 +
   .../msm/disp/dpu1/catalog/dpu_7_2_sc7280.h    |  1 +
   .../msm/disp/dpu1/catalog/dpu_8_0_sc8280xp.h  |  1 +
   .../msm/disp/dpu1/catalog/dpu_8_1_sm8450.h    |  1 +
   .../msm/disp/dpu1/catalog/dpu_9_0_sm8550.h    |  1 +
   .../gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h    | 31
++++++++++++++++++-
   14 files changed, 43 insertions(+), 1 deletion(-)


[skipped catalog changes]

diff --git a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h
b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h
index 677048cc3b7d..cc4aa75a1219 100644
--- a/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h
+++ b/drivers/gpu/drm/msm/disp/dpu1/dpu_hw_catalog.h
@@ -19,6 +19,33 @@
    */
   #define MAX_BLOCKS    12

+#define DPU_HW_VER(MAJOR, MINOR, STEP)\
+                 ((((unsigned int)MAJOR & 0xF) << 28) |\
+                 ((MINOR & 0xFFF) << 16) |\
+                 (STEP & 0xFFFF))
+
+#define DPU_HW_MAJOR(rev)((rev) >> 28)
+#define DPU_HW_MINOR(rev)(((rev) >> 16) & 0xFFF)
+#define DPU_HW_STEP(rev)((rev) & 0xFFFF)
+#define DPU_HW_MAJOR_MINOR(rev)((rev) >> 16)
+
+#define IS_DPU_MAJOR_MINOR_SAME(rev1, rev2)   \
+(DPU_HW_MAJOR_MINOR((rev1)) == DPU_HW_MAJOR_MINOR((rev2)))
+
+#define DPU_HW_VER_300 DPU_HW_VER(3, 0, 0) /* 8998 v1.0 */
+#define DPU_HW_VER_400 DPU_HW_VER(4, 0, 0) /* sdm845 v1.0 */
+#define DPU_HW_VER_500 DPU_HW_VER(5, 0, 0) /* sm8150 v1.0 */
+#define DPU_HW_VER_510 DPU_HW_VER(5, 1, 1) /* sc8180 */
+#define DPU_HW_VER_600 DPU_HW_VER(6, 0, 0) /* sm8250 */
+#define DPU_HW_VER_620 DPU_HW_VER(6, 2, 0) /* sc7180 v1.0 */
+#define DPU_HW_VER_630 DPU_HW_VER(6, 3, 0) /* sm6115|sm4250 */
+#define DPU_HW_VER_650 DPU_HW_VER(6, 5, 0) /* qcm2290|sm4125 */
+#define DPU_HW_VER_700 DPU_HW_VER(7, 0, 0) /* sm8350 */
+#define DPU_HW_VER_720 DPU_HW_VER(7, 2, 0) /* sc7280 */
+#define DPU_HW_VER_800 DPU_HW_VER(8, 0, 0) /* sc8280xp */
+#define DPU_HW_VER_810 DPU_HW_VER(8, 1, 0) /* sm8450 */
+#define DPU_HW_VER_900 DPU_HW_VER(9, 0, 0) /* sm8550 */

Instead of having defines for all SoCs (which can quickly become
unmanageable) and can cause merge conflicts, I'd suggest inlining
all
the defines into respective catalog files.


Sure, that can be done.

Also, I'm not sure that the "step" should be a part of the
catalog. I
know that this follows the hardware revision. However, please
correct
me if I'm wrong, different step levels are used for revisions of the
same SoC. The original code that was reading the hw revision from
the
hardware register, listed both 5.0.0 and 5.0.1 for sm8150.


This is one of the things i noticed while making this change.

Before the catalog rework, we used to handle even steps as we used
to read that from the register and match it with the mdss_cfg
handler. But after the rework, we dont handle steps anymore. Yes,
you are right that different step levels are used for the
revisions of the same SOC and so with that, i dont expect or
atleast am not aware of DPU differences between steps but I am not
able to rule it out.

So are you suggesting we drop step altogether and DPU_HW_VER()
macro shall only handle major and minor versions? With the current
chipsets I see, it should not make a difference . Its just that I
am not sure if that will never happen.

Yes. The goal of this rework would be to drop generic features and
to replace those checks with DPU-revision lookups. Correct?

Yes thats right.

I think that from this perspective having to handle toe step
revision is a sign of an overkill. Having to handle the step
revision is a sign of paltform feature (or mis-feature) rather than
a generic DPU bit.


Not entirely. Lets not forget that at the moment even dpu_perf_cfg
is part of the catalog. Even if in terms of major HW blocks steps
shouldnt change, there is absolutely no guarantee that perf data
cannot.

This is what is the sticking point for me which is holding me back
against dropping step. Thoughts?

We usually do not support ES versions of the chips, only the final
version. So supporting the perf data for earlier revisions is also
not required.


ack, we will drop step in that case. and good to know about the ES
versions.


In fact I suppose that even handling a minor revision would be an
overkill. Why don't we start with .dpu_major instead of .core_rev?
We can add .dpu_minor if/when required.


No, unfortunately we cannot drop minor version for sure. I am seeing
examples in downstream code where some of the features are available
after a minor verion as well.

Can you please give an example?


Yes, watchdog timer, intf reset counter are available only after DPU
HW version 8.1 (not major version 8).

Hmm, IIRC, wd timer was available for ages. Was it moved together with
the introduction of MDSS_PERIPH_0_REMOVED?


I am not sure of the timeline but its certainly tied to 8.1.

But anyway, I see your point. Let's have major and minor. I'd probably
still ask for the separate major and minor fields, if you don't mind.


hmmm so something like this?

+#define DPU_HW_VER_300 DPU_HW_VER(3, 0) /* 8998 v1.0 */

const struct dpu_mdss_cfg dpu_msm8998_cfg = {
.......
.dpu_major_rev = DPU_HW_MAJOR(DPU_HW_VER_300),
.dpu_minor_rev = DPU_HW_MINOR(DPU_HW_VER_300)

Just:

const struct dpu_mdss_cfg dpu_msm8998_cfg = {
     .dpu_major_rev = 3,
     .dpu_minor_rev = 0,
     /* .... */
};

We do not need a single enumeration of all the versions. It can easily
become a source of merge conflicts.


The issue with this approch is then the DPU_HW_VER_xxx macros become redundant but we should keep them. Because in the code, its much more readable to have

if (core_rev > DPU_HW_MAJOR(DPU_HW_VER_xxx))
     then enable feature;

But now we will have to do

if (dpu_major_rev > xxx && dpu_minor_ver > yyy)
     then enable feature;

/// probably folks will question this xxx and yyy as to what it means.

The first approach is less readable. It will require anybody to check, what is the major/minor of the mentioned XXX platform. In the second case we know exactly what we are looking for. E.g. we have new INTF interrupt addresses since 7.0. We have MDP_TOP_PERIPH0_REMOVED since 8.0 (or 8.1?) We have PP_TE until 5.0 (not included) and INTF_TE since 5.0.

Having DPU_HW_VER_foo, I'd have to look up each time, what is the HW revision of sm8350, sc8280xp, sm8150, etc.


Agreed, it will avoid one extra lookup but are you comfortable with a hard-coded number in the code? So for example.

if (dpu_major_rev > 0x3 && dpu_minor_ver > 0x5)
     enable feature;

Is this acceptable more than having to lookup?

Yes, definitely.

Note that this is not a correct condition for what you have meant.

Please excuse me for not being explicit. I assumed we have to enable feature since 4.6 (major > 3, minor > 5)

Proper condition would be:

if (dpu_major_rev > 4 ||
(dpu_major_rev == 4 && dpu_minor_rev >= 6))

--
With best wishes
Dmitry