[PATCH] drm/amdgpu: Apply IH Ptr mask after updating IH Read Ptr

[Ramesh Errabolu]

Apply IH Ptr mask immediately after updating to IH Read ptr.
Ideally the operation to update and mask should be atomic. This
will ensure that Read Ptr points to a valid index in the IH
ring buffer.

Signed-off-by: Ramesh Errabolu <Ramesh.Errabolu at amd.com>
---
 drivers/gpu/drm/amd/amdgpu/amdgpu_ih.c  | 5 ++++-
 drivers/gpu/drm/amd/amdgpu/cik_ih.c     | 5 ++++-
 drivers/gpu/drm/amd/amdgpu/cz_ih.c      | 5 ++++-
 drivers/gpu/drm/amd/amdgpu/iceland_ih.c | 5 ++++-
 drivers/gpu/drm/amd/amdgpu/si_ih.c      | 4 ++++
 drivers/gpu/drm/amd/amdgpu/tonga_ih.c   | 5 ++++-
 6 files changed, 24 insertions(+), 5 deletions(-)

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ih.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ih.c
index f3b0aaf3ebc6..2fd13d424213 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ih.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ih.c
@@ -280,8 +280,11 @@ void amdgpu_ih_decode_iv_helper(struct amdgpu_device *adev,
 	entry->src_data[2] = dw[6];
 	entry->src_data[3] = dw[7];
 
-	/* wptr/rptr are in bytes! */
+	/* Apply IH Ptr mask after adding sizeof(Intrpt)
+	 * bytes to IH Read ptr
+	 */
 	ih->rptr += 32;
+	ih->rptr &= ih->ptr_mask;
 }
 
 uint64_t amdgpu_ih_decode_iv_ts_helper(struct amdgpu_ih_ring *ih, u32 rptr,
diff --git a/drivers/gpu/drm/amd/amdgpu/cik_ih.c b/drivers/gpu/drm/amd/amdgpu/cik_ih.c
index 576baa9dbb0e..41c0c56d41f6 100644
--- a/drivers/gpu/drm/amd/amdgpu/cik_ih.c
+++ b/drivers/gpu/drm/amd/amdgpu/cik_ih.c
@@ -265,8 +265,11 @@ static void cik_ih_decode_iv(struct amdgpu_device *adev,
 	entry->vmid = (dw[2] >> 8) & 0xff;
 	entry->pasid = (dw[2] >> 16) & 0xffff;
 
-	/* wptr/rptr are in bytes! */
+	/* Apply IH Ptr mask after adding sizeof(Intrpt)
+	 * bytes to IH Read ptr
+	 */
 	ih->rptr += 16;
+	ih->rptr &= ih->ptr_mask;
 }
 
 /**
diff --git a/drivers/gpu/drm/amd/amdgpu/cz_ih.c b/drivers/gpu/drm/amd/amdgpu/cz_ih.c
index 072643787384..a94ddecc3d33 100644
--- a/drivers/gpu/drm/amd/amdgpu/cz_ih.c
+++ b/drivers/gpu/drm/amd/amdgpu/cz_ih.c
@@ -256,8 +256,11 @@ static void cz_ih_decode_iv(struct amdgpu_device *adev,
 	entry->vmid = (dw[2] >> 8) & 0xff;
 	entry->pasid = (dw[2] >> 16) & 0xffff;
 
-	/* wptr/rptr are in bytes! */
+	/* Apply IH Ptr mask after adding sizeof(Intrpt)
+	 * bytes to IH Read ptr
+	 */
 	ih->rptr += 16;
+	ih->rptr &= ih->ptr_mask;
 }
 
 /**
diff --git a/drivers/gpu/drm/amd/amdgpu/iceland_ih.c b/drivers/gpu/drm/amd/amdgpu/iceland_ih.c
index 07984f7c3ae7..d47f008110ba 100644
--- a/drivers/gpu/drm/amd/amdgpu/iceland_ih.c
+++ b/drivers/gpu/drm/amd/amdgpu/iceland_ih.c
@@ -255,8 +255,11 @@ static void iceland_ih_decode_iv(struct amdgpu_device *adev,
 	entry->vmid = (dw[2] >> 8) & 0xff;
 	entry->pasid = (dw[2] >> 16) & 0xffff;
 
-	/* wptr/rptr are in bytes! */
+	/* Apply IH Ptr mask after adding sizeof(Intrpt)
+	 * bytes to IH Read ptr
+	 */
 	ih->rptr += 16;
+	ih->rptr &= ih->ptr_mask;
 }
 
 /**
diff --git a/drivers/gpu/drm/amd/amdgpu/si_ih.c b/drivers/gpu/drm/amd/amdgpu/si_ih.c
index 5237395e4fab..9e51024f1851 100644
--- a/drivers/gpu/drm/amd/amdgpu/si_ih.c
+++ b/drivers/gpu/drm/amd/amdgpu/si_ih.c
@@ -147,7 +147,11 @@ static void si_ih_decode_iv(struct amdgpu_device *adev,
 	entry->ring_id = dw[2] & 0xff;
 	entry->vmid = (dw[2] >> 8) & 0xff;
 
+	/* Apply IH Ptr mask after adding sizeof(Intrpt)
+	 * bytes to IH Read ptr
+	 */
 	ih->rptr += 16;
+	ih->rptr &= ih->ptr_mask;
 }
 
 static void si_ih_set_rptr(struct amdgpu_device *adev,
diff --git a/drivers/gpu/drm/amd/amdgpu/tonga_ih.c b/drivers/gpu/drm/amd/amdgpu/tonga_ih.c
index 24d49d813607..db3c7aeb9425 100644
--- a/drivers/gpu/drm/amd/amdgpu/tonga_ih.c
+++ b/drivers/gpu/drm/amd/amdgpu/tonga_ih.c
@@ -259,8 +259,11 @@ static void tonga_ih_decode_iv(struct amdgpu_device *adev,
 	entry->vmid = (dw[2] >> 8) & 0xff;
 	entry->pasid = (dw[2] >> 16) & 0xffff;
 
-	/* wptr/rptr are in bytes! */
+	/* Apply IH Ptr mask after adding sizeof(Intrpt)
+	 * bytes to IH Read ptr
+	 */
 	ih->rptr += 16;
+	ih->rptr &= ih->ptr_mask;
 }
 
 /**
-- 
2.34.1