[PATCH 03/11] drm/amdgpu/ih: Don't perturb HW registers when accessing soft IH ring

["Timur Kristóf" <timur.kristof@gmail.com>]

The soft IH ring is implemented entirely in software.
We shouldn't read (or write) any HW registers when accessing it.

Signed-off-by: Timur Kristóf <timur.kristof@gmail.com>
Reviewed-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
---
 drivers/gpu/drm/amd/amdgpu/ih_v6_0.c   | 7 +++++++
 drivers/gpu/drm/amd/amdgpu/ih_v6_1.c   | 7 +++++++
 drivers/gpu/drm/amd/amdgpu/ih_v7_0.c   | 7 +++++++
 drivers/gpu/drm/amd/amdgpu/navi10_ih.c | 4 ++++
 4 files changed, 25 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdgpu/ih_v6_0.c b/drivers/gpu/drm/amd/amdgpu/ih_v6_0.c
index 512c76d97840..4470df45b7ea 100644
--- a/drivers/gpu/drm/amd/amdgpu/ih_v6_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/ih_v6_0.c
@@ -439,6 +439,10 @@ static u32 ih_v6_0_get_wptr(struct amdgpu_device *adev,
 	struct amdgpu_ih_regs *ih_regs;
 
 	wptr = le32_to_cpu(*ih->wptr_cpu);
+
+	if (ih == &adev->irq.ih_soft)
+		goto out;
+
 	ih_regs = &ih->ih_regs;
 
 	if (!REG_GET_FIELD(wptr, IH_RB_WPTR, RB_OVERFLOW))
@@ -514,6 +518,9 @@ static void ih_v6_0_set_rptr(struct amdgpu_device *adev,
 {
 	struct amdgpu_ih_regs *ih_regs;
 
+	if (ih == &adev->irq.ih_soft)
+		return;
+
 	if (ih->use_doorbell) {
 		/* XXX check if swapping is necessary on BE */
 		*ih->rptr_cpu = ih->rptr;
diff --git a/drivers/gpu/drm/amd/amdgpu/ih_v6_1.c b/drivers/gpu/drm/amd/amdgpu/ih_v6_1.c
index bae86e5fa316..6bbf89d048e7 100644
--- a/drivers/gpu/drm/amd/amdgpu/ih_v6_1.c
+++ b/drivers/gpu/drm/amd/amdgpu/ih_v6_1.c
@@ -410,6 +410,10 @@ static u32 ih_v6_1_get_wptr(struct amdgpu_device *adev,
 	struct amdgpu_ih_regs *ih_regs;
 
 	wptr = le32_to_cpu(*ih->wptr_cpu);
+
+	if (ih == &adev->irq.ih_soft)
+		goto out;
+
 	ih_regs = &ih->ih_regs;
 
 	if (!REG_GET_FIELD(wptr, IH_RB_WPTR, RB_OVERFLOW))
@@ -481,6 +485,9 @@ static void ih_v6_1_irq_rearm(struct amdgpu_device *adev,
 static void ih_v6_1_set_rptr(struct amdgpu_device *adev,
 			       struct amdgpu_ih_ring *ih)
 {
+	if (ih == &adev->irq.ih_soft)
+		return;
+
 	struct amdgpu_ih_regs *ih_regs;
 
 	if (ih->use_doorbell) {
diff --git a/drivers/gpu/drm/amd/amdgpu/ih_v7_0.c b/drivers/gpu/drm/amd/amdgpu/ih_v7_0.c
index 6265ee4b0ff1..f271bc8c4859 100644
--- a/drivers/gpu/drm/amd/amdgpu/ih_v7_0.c
+++ b/drivers/gpu/drm/amd/amdgpu/ih_v7_0.c
@@ -460,6 +460,10 @@ static u32 ih_v7_0_get_wptr(struct amdgpu_device *adev,
 	struct amdgpu_ih_regs *ih_regs;
 
 	wptr = le32_to_cpu(*ih->wptr_cpu);
+
+	if (ih == &adev->irq.ih_soft)
+		goto out;
+
 	ih_regs = &ih->ih_regs;
 
 	if (!REG_GET_FIELD(wptr, IH_RB_WPTR, RB_OVERFLOW))
@@ -530,6 +534,9 @@ static void ih_v7_0_set_rptr(struct amdgpu_device *adev,
 {
 	struct amdgpu_ih_regs *ih_regs;
 
+	if (ih == &adev->irq.ih_soft)
+		return;
+
 	if (ih->use_doorbell) {
 		/* XXX check if swapping is necessary on BE */
 		*ih->rptr_cpu = ih->rptr;
diff --git a/drivers/gpu/drm/amd/amdgpu/navi10_ih.c b/drivers/gpu/drm/amd/amdgpu/navi10_ih.c
index 7a167ad93fd0..1dae7df9ee17 100644
--- a/drivers/gpu/drm/amd/amdgpu/navi10_ih.c
+++ b/drivers/gpu/drm/amd/amdgpu/navi10_ih.c
@@ -417,6 +417,10 @@ static u32 navi10_ih_get_wptr(struct amdgpu_device *adev,
 		 */
 		wptr = le32_to_cpu(*ih->wptr_cpu);
 
+		if (ih == &adev->irq.ih_soft)
+			goto out;
+
+
 		if (!REG_GET_FIELD(wptr, IH_RB_WPTR, RB_OVERFLOW))
 			goto out;
 	}
-- 
2.55.0