From 26f32a377eeddc5af24821b1ef3a3a8de7a80211 Mon Sep 17 00:00:00 2001
From: Christian König <christian.koenig@amd.com>
Date: Sat, 31 Oct 2020 18:38:15 +0100
Subject: drm/amdgpu: add infrastructure for soft IH ring
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Add a soft IH ring implementation similar to the hardware IH1/2.
This can be used if the hardware delegation of interrupts to IH1/2
doesn't work for some reason.
Signed-off-by: Christian König <christian.koenig@amd.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_ih.c | 29 +++++++++++++++++++++++++++++
1 file changed, 29 insertions(+)
(limited to 'drivers/gpu/drm/amd/amdgpu/amdgpu_ih.c')
diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_ih.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_ih.c
index 111a301ce878..dcd9b4a8e20b 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_ih.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_ih.c
@@ -131,6 +131,35 @@ void amdgpu_ih_ring_fini(struct amdgpu_device *adev, struct amdgpu_ih_ring *ih)
}
}
+/**
+ * amdgpu_ih_ring_write - write IV to the ring buffer
+ *
+ * @ih: ih ring to write to
+ * @iv: the iv to write
+ * @num_dw: size of the iv in dw
+ *
+ * Writes an IV to the ring buffer using the CPU and increment the wptr.
+ * Used for testing and delegating IVs to a software ring.
+ */
+void amdgpu_ih_ring_write(struct amdgpu_ih_ring *ih, const uint32_t *iv,
+ unsigned int num_dw)
+{
+ uint32_t wptr = le32_to_cpu(*ih->wptr_cpu) >> 2;
+ unsigned int i;
+
+ for (i = 0; i < num_dw; ++i)
+ ih->ring[wptr++] = cpu_to_le32(iv[i]);
+
+ wptr <<= 2;
+ wptr &= ih->ptr_mask;
+
+ /* Only commit the new wptr if we don't overflow */
+ if (wptr != READ_ONCE(ih->rptr)) {
+ wmb();
+ WRITE_ONCE(*ih->wptr_cpu, cpu_to_le32(wptr));
+ }
+}
+
/**
* amdgpu_ih_process - interrupt handler
*
--
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