[PATCH] arm64: cache: Lower ARCH_DMA_MINALIGN to 64 (L1_CACHE_BYTES)

[Arnd Bergmann]

On Wed, Jun 2, 2021 at 4:28 PM Marek Szyprowski
<m.szyprowski at samsung.com> wrote:
>
> On 02.06.2021 16:14, Arnd Bergmann wrote:
> > On Wed, Jun 2, 2021 at 4:09 PM Marek Szyprowski
> > <m.szyprowski at samsung.com> wrote:
> >> On 02.06.2021 15:51, Mark Rutland wrote:
> >> [   13.938691] debugfs: Directory '3f902000.hdmi' with parent 'vc4-hdmi'
> >> already present!
> >> [   13.983716] vc4-drm soc:gpu: bound 3f902000.hdmi (ops vc4_hdmi_ops)
> >> [   13.991816] vc4-drm soc:gpu: bound 3f806000.vec (ops vc4_vec_ops)
> >> [   14.000945] vc4-drm soc:gpu: bound 3f400000.hvs (ops vc4_hvs_ops)
> >> [   14.009644] vc4-drm soc:gpu: bound 3f004000.txp (ops vc4_txp_ops)
> >> [   14.017547] vc4-drm soc:gpu: bound 3f206000.pixelvalve (ops vc4_crtc_ops)
> >> [   14.025780] vc4-drm soc:gpu: bound 3f207000.pixelvalve (ops vc4_crtc_ops)
> >> [   14.033995] vc4-drm soc:gpu: bound 3f807000.pixelvalve (ops vc4_crtc_ops)
> >> [   14.042196] vc4-drm soc:gpu: bound 3fc00000.v3d (ops vc4_v3d_ops)
> >> [....] Waiting for /dev to be fully populated...[   14.112812] [drm]
> >> Initialized vc4 0.0.0 20140616 for soc:gpu on minor 0
> >> done.
> > I wonder if the vc4's cache is involved here rather than the CPU cache.
> > If it's that, then removing the vc4 drivers should make it boot reliably, and
> > it might be possible to fix it by manually padding any allocations that get
> > passed to the GPU.
>
> Indeed, after disabling DRM_VC4 in the .config, system boots fine and
> seems to be working correctly.

Ok, that helps. This means there is a good chance it would be one of these:

$ git grep k[cmz]alloc drivers/gpu/drm/vc4
drivers/gpu/drm/vc4/vc4_bo.c:           new_list =
kmalloc_array(new_size, sizeof(struct list_head),
drivers/gpu/drm/vc4/vc4_bo.c:   bo = kzalloc(sizeof(*bo), GFP_KERNEL);
drivers/gpu/drm/vc4/vc4_bo.c:   vc4->bo_labels =
kcalloc(VC4_BO_TYPE_COUNT, sizeof(*vc4->bo_labels),
drivers/gpu/drm/vc4/vc4_crtc.c: flip_state =
kzalloc(sizeof(*flip_state), GFP_KERNEL);
drivers/gpu/drm/vc4/vc4_crtc.c: vc4_state =
kzalloc(sizeof(*vc4_state), GFP_KERNEL);
drivers/gpu/drm/vc4/vc4_crtc.c: vc4_crtc_state =
kzalloc(sizeof(*vc4_crtc_state), GFP_KERNEL);
drivers/gpu/drm/vc4/vc4_crtc.c: vc4_crtc = devm_kzalloc(dev,
sizeof(*vc4_crtc), GFP_KERNEL);
drivers/gpu/drm/vc4/vc4_debugfs.c:              devm_kzalloc(dev->dev,
sizeof(*entry), GFP_KERNEL);
drivers/gpu/drm/vc4/vc4_dpi.c:  dpi = devm_kzalloc(dev, sizeof(*dpi),
GFP_KERNEL);
drivers/gpu/drm/vc4/vc4_dpi.c:  vc4_dpi_encoder = devm_kzalloc(dev,
sizeof(*vc4_dpi_encoder),
drivers/gpu/drm/vc4/vc4_drv.c:  vc4file = kzalloc(sizeof(*vc4file), GFP_KERNEL);
drivers/gpu/drm/vc4/vc4_dsi.c:  dsi->clk_onecell = devm_kzalloc(dev,
drivers/gpu/drm/vc4/vc4_dsi.c:  vc4_dsi_encoder = devm_kzalloc(dev,
sizeof(*vc4_dsi_encoder),
drivers/gpu/drm/vc4/vc4_dsi.c:  dsi = devm_kzalloc(dev, sizeof(*dsi),
GFP_KERNEL);
drivers/gpu/drm/vc4/vc4_gem.c:  bo_state = kcalloc(state->bo_count,
sizeof(*bo_state), GFP_KERNEL);
drivers/gpu/drm/vc4/vc4_gem.c:  kernel_state = kcalloc(1,
sizeof(*kernel_state), GFP_KERNEL);
drivers/gpu/drm/vc4/vc4_gem.c:  kernel_state->bo = kcalloc(state->bo_count,
drivers/gpu/drm/vc4/vc4_gem.c:  fence = kzalloc(sizeof(*fence), GFP_KERNEL);
drivers/gpu/drm/vc4/vc4_gem.c:  exec = kcalloc(1, sizeof(*exec), GFP_KERNEL);
drivers/gpu/drm/vc4/vc4_hdmi.c:         kzalloc(sizeof(*new_state), GFP_KERNEL);
drivers/gpu/drm/vc4/vc4_hdmi.c: new_state =
kzalloc(sizeof(*new_state), GFP_KERNEL);
drivers/gpu/drm/vc4/vc4_hdmi.c: regs = kcalloc(variant->num_registers,
sizeof(*regs),
drivers/gpu/drm/vc4/vc4_hdmi.c: vc4_hdmi = devm_kzalloc(dev,
sizeof(*vc4_hdmi), GFP_KERNEL);
drivers/gpu/drm/vc4/vc4_hvs.c:  hvs = devm_kzalloc(&pdev->dev,
sizeof(*hvs), GFP_KERNEL);
drivers/gpu/drm/vc4/vc4_kms.c:  ctm_state =
kzalloc(sizeof(*ctm_state), GFP_KERNEL);
drivers/gpu/drm/vc4/vc4_kms.c:  load_state =
kzalloc(sizeof(*load_state), GFP_KERNEL);
drivers/gpu/drm/vc4/vc4_kms.c:  state = kzalloc(sizeof(*state), GFP_KERNEL);
drivers/gpu/drm/vc4/vc4_kms.c:  state = kzalloc(sizeof(*state), GFP_KERNEL);
drivers/gpu/drm/vc4/vc4_perfmon.c:      perfmon =
kzalloc(struct_size(perfmon, counters, req->ncounters),
drivers/gpu/drm/vc4/vc4_plane.c:        vc4_state =
kzalloc(sizeof(*vc4_state), GFP_KERNEL);
drivers/gpu/drm/vc4/vc4_plane.c:                u32 *new_dlist =
kmalloc_array(new_size, 4, GFP_KERNEL);
drivers/gpu/drm/vc4/vc4_plane.c:        vc4_plane =
devm_kzalloc(dev->dev, sizeof(*vc4_plane),
drivers/gpu/drm/vc4/vc4_txp.c:  txp = devm_kzalloc(dev, sizeof(*txp),
GFP_KERNEL);
drivers/gpu/drm/vc4/vc4_v3d.c:  v3d = devm_kzalloc(&pdev->dev,
sizeof(*v3d), GFP_KERNEL);
drivers/gpu/drm/vc4/vc4_validate_shaders.c:
kcalloc(BITS_TO_LONGS(validation_state.max_ip),
drivers/gpu/drm/vc4/vc4_validate_shaders.c:     validated_shader =
kcalloc(1, sizeof(*validated_shader), GFP_KERNEL);
drivers/gpu/drm/vc4/vc4_vec.c:  vec_connector = devm_kzalloc(dev->dev,
sizeof(*vec_connector),
drivers/gpu/drm/vc4/vc4_vec.c:  vec = devm_kzalloc(dev, sizeof(*vec),
GFP_KERNEL);
drivers/gpu/drm/vc4/vc4_vec.c:  vc4_vec_encoder = devm_kzalloc(dev,
sizeof(*vc4_vec_encoder),

I suppose most can be easily ruled out because they are not shared, or
because they are larger
than 64 bytes. I'll have a quick look if I find any smoking guns.

       Arnd