On 3/14/25 10:08 PM, Rob Clark wrote:
On Fri, Mar 14, 2025 at 1:07 PM Akhil P Oommen <[email protected]> wrote:

On 3/15/2025 12:04 AM, Rob Clark wrote:
From: Rob Clark <[email protected]>

IB_SIZE is only b0..b19.  Starting with a6xx gen3, additional fields
were added above the IB_SIZE.  Accidentially setting them can cause
badness.  Fix this by properly defining the CP_INDIRECT_BUFFER packet
and using the generated builder macro to ensure unintended bits are not
set.

I wonder if we should be returning -EINVAL from the ioctl when a size larger than max is submitted. I say this because we do a 0 check when submitting which this bug allows to bypass therefore putting a 0 sized CP_INDIRECT_BUFFER pkt in the ring. Fw is inconsistent as to how this is treated (should be a NOP but will sometimes hang) and that is very confusing.


v2: add missing type attribute for IB_BASE

Reported-by: Connor Abbott <[email protected]>
Fixes: a83366ef19ea ("drm/msm/a6xx: add A640/A650 to gpulist")
Signed-off-by: Rob Clark <[email protected]>
---
Backport notes, prior to commit ae22a94997b8 ("drm/msm: import A2xx-A4xx
XML display registers database"), just open code, ie:

    OUT_RING(ring, submit->cmd[i].size & 0xfffff);

Prior to commit af66706accdf ("drm/msm/a6xx: Add skeleton A7xx
support"), a7xx_submit() did not exist so that hunk can be dropped.

  drivers/gpu/drm/msm/adreno/a6xx_gpu.c               | 8 ++++----
  drivers/gpu/drm/msm/registers/adreno/adreno_pm4.xml | 7 +++++++
  2 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c 
b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
index d3978cfa3f20..ea52b7d0b212 100644
--- a/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
+++ b/drivers/gpu/drm/msm/adreno/a6xx_gpu.c
@@ -245,10 +245,10 @@ static void a6xx_submit(struct msm_gpu *gpu, struct 
msm_gem_submit *submit)
                               break;
                       fallthrough;
               case MSM_SUBMIT_CMD_BUF:
-                     OUT_PKT7(ring, CP_INDIRECT_BUFFER_PFE, 3);
+                     OUT_PKT7(ring, CP_INDIRECT_BUFFER, 3);
                       OUT_RING(ring, lower_32_bits(submit->cmd[i].iova));
                       OUT_RING(ring, upper_32_bits(submit->cmd[i].iova));
-                     OUT_RING(ring, submit->cmd[i].size);
+                     OUT_RING(ring, 
A5XX_CP_INDIRECT_BUFFER_3_IB_SIZE(submit->cmd[i].size));
                       ibs++;
                       break;
               }
@@ -382,10 +382,10 @@ static void a7xx_submit(struct msm_gpu *gpu, struct 
msm_gem_submit *submit)
                               break;
                       fallthrough;
               case MSM_SUBMIT_CMD_BUF:
-                     OUT_PKT7(ring, CP_INDIRECT_BUFFER_PFE, 3);
+                     OUT_PKT7(ring, CP_INDIRECT_BUFFER, 3);
                       OUT_RING(ring, lower_32_bits(submit->cmd[i].iova));
                       OUT_RING(ring, upper_32_bits(submit->cmd[i].iova));
-                     OUT_RING(ring, submit->cmd[i].size);
+                     OUT_RING(ring, 
A5XX_CP_INDIRECT_BUFFER_3_IB_SIZE(submit->cmd[i].size));
                       ibs++;
                       break;
               }
diff --git a/drivers/gpu/drm/msm/registers/adreno/adreno_pm4.xml 
b/drivers/gpu/drm/msm/registers/adreno/adreno_pm4.xml
index 55a35182858c..a71bc6f16cbf 100644
--- a/drivers/gpu/drm/msm/registers/adreno/adreno_pm4.xml
+++ b/drivers/gpu/drm/msm/registers/adreno/adreno_pm4.xml
@@ -2259,5 +2259,12 @@ opcode: CP_LOAD_STATE4 (30) (4 dwords)
       </reg32>
  </domain>

+<domain name="CP_INDIRECT_BUFFER" width="32" varset="chip" prefix="chip" 
variants="A5XX-">
+     <reg64 offset="0" name="IB_BASE" type="address"/>
+     <reg32 offset="3" name="3">

Why is the offset 3 here? It looks to me that it doesn't match the code
above.

oh, bad copy/pasta.. it should be 2 (dword offset)

BR,
-R

-Akhil.

+             <bitfield name="IB_SIZE" low="0" high="19"/>
+     </reg32>
+</domain>
+
  </database>



Best regards,
--
Antonino Maniscalco <[email protected]>

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