drm/amdgpu: add irq domain support

Hardware blocks on the GPU like ACP generate interrupts in
the GPU interrupt controller, but are driven by a separate
driver.  Add an irq domain to the GPU driver so that
blocks like ACP can register a Linux interrupt.

Acked-by: Dave Airlie <airlied@redhat.com>
Acked-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

1 files changed, 100 insertions, 8 deletions

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c
index 7c42ff670080..3006182c5d0d 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_irq.c
@@ -312,6 +312,7 @@ int amdgpu_irq_add_id(struct amdgpu_device *adev, unsigned src_id,
         }
 
         adev->irq.sources[src_id] = source;
+
         return 0;
 }
 
@@ -335,15 +336,19 @@ void amdgpu_irq_dispatch(struct amdgpu_device *adev,
                 return;
         }
 
-        src = adev->irq.sources[src_id];
-        if (!src) {
-                DRM_DEBUG("Unhandled interrupt src_id: %d\n", src_id);
-                return;
-        }
+        if (adev->irq.virq[src_id]) {
+                generic_handle_irq(irq_find_mapping(adev->irq.domain, src_id));
+        } else {
+                src = adev->irq.sources[src_id];
+                if (!src) {
+                        DRM_DEBUG("Unhandled interrupt src_id: %d\n", src_id);
+                        return;
+                }
 
-        r = src->funcs->process(adev, src, entry);
-        if (r)
-                DRM_ERROR("error processing interrupt (%d)\n", r);
+                r = src->funcs->process(adev, src, entry);
+                if (r)
+                        DRM_ERROR("error processing interrupt (%d)\n", r);
+        }
 }
 
 /**
@@ -461,3 +466,90 @@ bool amdgpu_irq_enabled(struct amdgpu_device *adev, struct amdgpu_irq_src *src,
 
         return !!atomic_read(&src->enabled_types[type]);
 }
+
+/* gen irq */
+static void amdgpu_irq_mask(struct irq_data *irqd)
+{
+        /* XXX */
+}
+
+static void amdgpu_irq_unmask(struct irq_data *irqd)
+{
+        /* XXX */
+}
+
+static struct irq_chip amdgpu_irq_chip = {
+        .name = "amdgpu-ih",
+        .irq_mask = amdgpu_irq_mask,
+        .irq_unmask = amdgpu_irq_unmask,
+};
+
+static int amdgpu_irqdomain_map(struct irq_domain *d,
+                                unsigned int irq, irq_hw_number_t hwirq)
+{
+        if (hwirq >= AMDGPU_MAX_IRQ_SRC_ID)
+                return -EPERM;
+
+        irq_set_chip_and_handler(irq,
+                                 &amdgpu_irq_chip, handle_simple_irq);
+        return 0;
+}
+
+static struct irq_domain_ops amdgpu_hw_irqdomain_ops = {
+        .map = amdgpu_irqdomain_map,
+};
+
+/**
+ * amdgpu_irq_add_domain - create a linear irq domain
+ *
+ * @adev: amdgpu device pointer
+ *
+ * Create an irq domain for GPU interrupt sources
+ * that may be driven by another driver (e.g., ACP).
+ */
+int amdgpu_irq_add_domain(struct amdgpu_device *adev)
+{
+        adev->irq.domain = irq_domain_add_linear(NULL, AMDGPU_MAX_IRQ_SRC_ID,
+                                                 &amdgpu_hw_irqdomain_ops, adev);
+        if (!adev->irq.domain) {
+                DRM_ERROR("GPU irq add domain failed\n");
+                return -ENODEV;
+        }
+
+        return 0;
+}
+
+/**
+ * amdgpu_irq_remove_domain - remove the irq domain
+ *
+ * @adev: amdgpu device pointer
+ *
+ * Remove the irq domain for GPU interrupt sources
+ * that may be driven by another driver (e.g., ACP).
+ */
+void amdgpu_irq_remove_domain(struct amdgpu_device *adev)
+{
+        if (adev->irq.domain) {
+                irq_domain_remove(adev->irq.domain);
+                adev->irq.domain = NULL;
+        }
+}
+
+/**
+ * amdgpu_irq_create_mapping - create a mapping between a domain irq and a
+ *                             Linux irq
+ *
+ * @adev: amdgpu device pointer
+ * @src_id: IH source id
+ *
+ * Create a mapping between a domain irq (GPU IH src id) and a Linux irq
+ * Use this for components that generate a GPU interrupt, but are driven
+ * by a different driver (e.g., ACP).
+ * Returns the Linux irq.
+ */
+unsigned amdgpu_irq_create_mapping(struct amdgpu_device *adev, unsigned src_id)
+{
+        adev->irq.virq[src_id] = irq_create_mapping(adev->irq.domain, src_id);
+
+        return adev->irq.virq[src_id];
+}