drm/amdgpu: add irq domain support

BugLink: http://bugs.launchpad.net/bugs/1546572

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>
(cherry picked from commit 5f232365)
Signed-off-by: Alberto Milone <alberto.milone@canonical.com>
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>

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];
+}

drivers/gpu/drm/amd/amdgpu/amdgpu_irq.h

@@ -24,6 +24,7 @@
 #ifndef __AMDGPU_IRQ_H__
 #define __AMDGPU_IRQ_H__
 
+#include <linux/irqdomain.h>
 #include "amdgpu_ih.h"
 
 #define AMDGPU_MAX_IRQ_SRC_ID	0x100
@@ -65,6 +66,10 @@ struct amdgpu_irq {
 	/* interrupt ring */
 	struct amdgpu_ih_ring		ih;
 	const struct amdgpu_ih_funcs	*ih_funcs;
+
+	/* gen irq stuff */
+	struct irq_domain		*domain; /* GPU irq controller domain */
+	unsigned			virq[AMDGPU_MAX_IRQ_SRC_ID];
 };
 
 void amdgpu_irq_preinstall(struct drm_device *dev);
@@ -90,4 +95,8 @@ int amdgpu_irq_put(struct amdgpu_device *adev, struct amdgpu_irq_src *src,
 bool amdgpu_irq_enabled(struct amdgpu_device *adev, struct amdgpu_irq_src *src,
 			unsigned type);
 
+int amdgpu_irq_add_domain(struct amdgpu_device *adev);
+void amdgpu_irq_remove_domain(struct amdgpu_device *adev);
+unsigned amdgpu_irq_create_mapping(struct amdgpu_device *adev, unsigned src_id);
+
 #endif

drivers/gpu/drm/amd/amdgpu/cik_ih.c

@@ -274,6 +274,11 @@ static void cik_ih_set_rptr(struct amdgpu_device *adev)
 static int cik_ih_early_init(void *handle)
 {
 	struct amdgpu_device *adev = (struct amdgpu_device *)handle;
+	int ret;
+
+	ret = amdgpu_irq_add_domain(adev);
+	if (ret)
+		return ret;
 
 	cik_ih_set_interrupt_funcs(adev);
 
@@ -300,6 +305,7 @@ static int cik_ih_sw_fini(void *handle)
 
 	amdgpu_irq_fini(adev);
 	amdgpu_ih_ring_fini(adev);
+	amdgpu_irq_remove_domain(adev);
 
 	return 0;
 }

drivers/gpu/drm/amd/amdgpu/cz_ih.c

@@ -253,8 +253,14 @@ static void cz_ih_set_rptr(struct amdgpu_device *adev)
 static int cz_ih_early_init(void *handle)
 {
 	struct amdgpu_device *adev = (struct amdgpu_device *)handle;
+	int ret;
+
+	ret = amdgpu_irq_add_domain(adev);
+	if (ret)
+		return ret;
 
 	cz_ih_set_interrupt_funcs(adev);
+
 	return 0;
 }
 
@@ -278,6 +284,7 @@ static int cz_ih_sw_fini(void *handle)
 
 	amdgpu_irq_fini(adev);
 	amdgpu_ih_ring_fini(adev);
+	amdgpu_irq_remove_domain(adev);
 
 	return 0;
 }

drivers/gpu/drm/amd/amdgpu/iceland_ih.c

@@ -253,8 +253,14 @@ static void iceland_ih_set_rptr(struct amdgpu_device *adev)
 static int iceland_ih_early_init(void *handle)
 {
 	struct amdgpu_device *adev = (struct amdgpu_device *)handle;
+	int ret;
+
+	ret = amdgpu_irq_add_domain(adev);
+	if (ret)
+		return ret;
 
 	iceland_ih_set_interrupt_funcs(adev);
+
 	return 0;
 }
 
@@ -278,6 +284,7 @@ static int iceland_ih_sw_fini(void *handle)
 
 	amdgpu_irq_fini(adev);
 	amdgpu_ih_ring_fini(adev);
+	amdgpu_irq_remove_domain(adev);
 
 	return 0;
 }

drivers/gpu/drm/amd/amdgpu/tonga_ih.c

@@ -273,8 +273,14 @@ static void tonga_ih_set_rptr(struct amdgpu_device *adev)
 static int tonga_ih_early_init(void *handle)
 {
 	struct amdgpu_device *adev = (struct amdgpu_device *)handle;
+	int ret;
+
+	ret = amdgpu_irq_add_domain(adev);
+	if (ret)
+		return ret;
 
 	tonga_ih_set_interrupt_funcs(adev);
+
 	return 0;
 }
 
@@ -301,6 +307,7 @@ static int tonga_ih_sw_fini(void *handle)
 
 	amdgpu_irq_fini(adev);
 	amdgpu_ih_ring_fini(adev);
+	amdgpu_irq_add_domain(adev);
 
 	return 0;
 }