From 1622ab3d63c27a59f7ba0a514d1d33e26238fcfe Mon Sep 17 00:00:00 2001 From: Defang Bo Date: Wed, 6 Jan 2021 00:06:39 +0800 Subject: [PATCH] drm/amdgpu: Add check to prevent IH overflow MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit [ Upstream commit e4180c4253f3f2da09047f5139959227f5cf1173 ] Similar to commit ("drm/amdgpu: fix IH overflow on Vega10 v2"). When an ring buffer overflow happens the appropriate bit is set in the WPTR register which is also written back to memory. But clearing the bit in the WPTR doesn't trigger another memory writeback. So what can happen is that we end up processing the buffer overflow over and over again because the bit is never cleared. Resulting in a random system lockup because of an infinite loop in an interrupt handler. Reviewed-by: Christian König Signed-off-by: Defang Bo Signed-off-by: Alex Deucher Signed-off-by: Sasha Levin --- drivers/gpu/drm/amd/amdgpu/cz_ih.c | 37 ++++++++++++++++--------- drivers/gpu/drm/amd/amdgpu/iceland_ih.c | 36 +++++++++++++++--------- drivers/gpu/drm/amd/amdgpu/tonga_ih.c | 37 ++++++++++++++++--------- 3 files changed, 71 insertions(+), 39 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/cz_ih.c b/drivers/gpu/drm/amd/amdgpu/cz_ih.c index da37f8a900afb..307c01301c87a 100644 --- a/drivers/gpu/drm/amd/amdgpu/cz_ih.c +++ b/drivers/gpu/drm/amd/amdgpu/cz_ih.c @@ -194,19 +194,30 @@ static u32 cz_ih_get_wptr(struct amdgpu_device *adev, wptr = le32_to_cpu(*ih->wptr_cpu); - if (REG_GET_FIELD(wptr, IH_RB_WPTR, RB_OVERFLOW)) { - wptr = REG_SET_FIELD(wptr, IH_RB_WPTR, RB_OVERFLOW, 0); - /* When a ring buffer overflow happen start parsing interrupt - * from the last not overwritten vector (wptr + 16). Hopefully - * this should allow us to catchup. - */ - dev_warn(adev->dev, "IH ring buffer overflow (0x%08X, 0x%08X, 0x%08X)\n", - wptr, ih->rptr, (wptr + 16) & ih->ptr_mask); - ih->rptr = (wptr + 16) & ih->ptr_mask; - tmp = RREG32(mmIH_RB_CNTL); - tmp = REG_SET_FIELD(tmp, IH_RB_CNTL, WPTR_OVERFLOW_CLEAR, 1); - WREG32(mmIH_RB_CNTL, tmp); - } + if (!REG_GET_FIELD(wptr, IH_RB_WPTR, RB_OVERFLOW)) + goto out; + + /* Double check that the overflow wasn't already cleared. */ + wptr = RREG32(mmIH_RB_WPTR); + + if (!REG_GET_FIELD(wptr, IH_RB_WPTR, RB_OVERFLOW)) + goto out; + + wptr = REG_SET_FIELD(wptr, IH_RB_WPTR, RB_OVERFLOW, 0); + + /* When a ring buffer overflow happen start parsing interrupt + * from the last not overwritten vector (wptr + 16). Hopefully + * this should allow us to catchup. + */ + dev_warn(adev->dev, "IH ring buffer overflow (0x%08X, 0x%08X, 0x%08X)\n", + wptr, ih->rptr, (wptr + 16) & ih->ptr_mask); + ih->rptr = (wptr + 16) & ih->ptr_mask; + tmp = RREG32(mmIH_RB_CNTL); + tmp = REG_SET_FIELD(tmp, IH_RB_CNTL, WPTR_OVERFLOW_CLEAR, 1); + WREG32(mmIH_RB_CNTL, tmp); + + +out: return (wptr & ih->ptr_mask); } diff --git a/drivers/gpu/drm/amd/amdgpu/iceland_ih.c b/drivers/gpu/drm/amd/amdgpu/iceland_ih.c index 37d8b6ca4dab8..cc957471f31ea 100644 --- a/drivers/gpu/drm/amd/amdgpu/iceland_ih.c +++ b/drivers/gpu/drm/amd/amdgpu/iceland_ih.c @@ -194,19 +194,29 @@ static u32 iceland_ih_get_wptr(struct amdgpu_device *adev, wptr = le32_to_cpu(*ih->wptr_cpu); - if (REG_GET_FIELD(wptr, IH_RB_WPTR, RB_OVERFLOW)) { - wptr = REG_SET_FIELD(wptr, IH_RB_WPTR, RB_OVERFLOW, 0); - /* When a ring buffer overflow happen start parsing interrupt - * from the last not overwritten vector (wptr + 16). Hopefully - * this should allow us to catchup. - */ - dev_warn(adev->dev, "IH ring buffer overflow (0x%08X, 0x%08X, 0x%08X)\n", - wptr, ih->rptr, (wptr + 16) & ih->ptr_mask); - ih->rptr = (wptr + 16) & ih->ptr_mask; - tmp = RREG32(mmIH_RB_CNTL); - tmp = REG_SET_FIELD(tmp, IH_RB_CNTL, WPTR_OVERFLOW_CLEAR, 1); - WREG32(mmIH_RB_CNTL, tmp); - } + if (!REG_GET_FIELD(wptr, IH_RB_WPTR, RB_OVERFLOW)) + goto out; + + /* Double check that the overflow wasn't already cleared. */ + wptr = RREG32(mmIH_RB_WPTR); + + if (!REG_GET_FIELD(wptr, IH_RB_WPTR, RB_OVERFLOW)) + goto out; + + wptr = REG_SET_FIELD(wptr, IH_RB_WPTR, RB_OVERFLOW, 0); + /* When a ring buffer overflow happen start parsing interrupt + * from the last not overwritten vector (wptr + 16). Hopefully + * this should allow us to catchup. + */ + dev_warn(adev->dev, "IH ring buffer overflow (0x%08X, 0x%08X, 0x%08X)\n", + wptr, ih->rptr, (wptr + 16) & ih->ptr_mask); + ih->rptr = (wptr + 16) & ih->ptr_mask; + tmp = RREG32(mmIH_RB_CNTL); + tmp = REG_SET_FIELD(tmp, IH_RB_CNTL, WPTR_OVERFLOW_CLEAR, 1); + WREG32(mmIH_RB_CNTL, tmp); + + +out: return (wptr & ih->ptr_mask); } diff --git a/drivers/gpu/drm/amd/amdgpu/tonga_ih.c b/drivers/gpu/drm/amd/amdgpu/tonga_ih.c index ce3319993b4bd..249fcbee7871c 100644 --- a/drivers/gpu/drm/amd/amdgpu/tonga_ih.c +++ b/drivers/gpu/drm/amd/amdgpu/tonga_ih.c @@ -196,19 +196,30 @@ static u32 tonga_ih_get_wptr(struct amdgpu_device *adev, wptr = le32_to_cpu(*ih->wptr_cpu); - if (REG_GET_FIELD(wptr, IH_RB_WPTR, RB_OVERFLOW)) { - wptr = REG_SET_FIELD(wptr, IH_RB_WPTR, RB_OVERFLOW, 0); - /* When a ring buffer overflow happen start parsing interrupt - * from the last not overwritten vector (wptr + 16). Hopefully - * this should allow us to catchup. - */ - dev_warn(adev->dev, "IH ring buffer overflow (0x%08X, 0x%08X, 0x%08X)\n", - wptr, ih->rptr, (wptr + 16) & ih->ptr_mask); - ih->rptr = (wptr + 16) & ih->ptr_mask; - tmp = RREG32(mmIH_RB_CNTL); - tmp = REG_SET_FIELD(tmp, IH_RB_CNTL, WPTR_OVERFLOW_CLEAR, 1); - WREG32(mmIH_RB_CNTL, tmp); - } + if (!REG_GET_FIELD(wptr, IH_RB_WPTR, RB_OVERFLOW)) + goto out; + + /* Double check that the overflow wasn't already cleared. */ + wptr = RREG32(mmIH_RB_WPTR); + + if (!REG_GET_FIELD(wptr, IH_RB_WPTR, RB_OVERFLOW)) + goto out; + + wptr = REG_SET_FIELD(wptr, IH_RB_WPTR, RB_OVERFLOW, 0); + + /* When a ring buffer overflow happen start parsing interrupt + * from the last not overwritten vector (wptr + 16). Hopefully + * this should allow us to catchup. + */ + + dev_warn(adev->dev, "IH ring buffer overflow (0x%08X, 0x%08X, 0x%08X)\n", + wptr, ih->rptr, (wptr + 16) & ih->ptr_mask); + ih->rptr = (wptr + 16) & ih->ptr_mask; + tmp = RREG32(mmIH_RB_CNTL); + tmp = REG_SET_FIELD(tmp, IH_RB_CNTL, WPTR_OVERFLOW_CLEAR, 1); + WREG32(mmIH_RB_CNTL, tmp); + +out: return (wptr & ih->ptr_mask); }