drm/radeon/kms: Add support for interrupts on r6xx/r7xx chips (v3)

This enables the use of interrupts on r6xx/r7xx hardware.
Interrupts are implemented via a ring buffer.  The GPU adds
interrupts vectors to the ring and the host reads them off
in the interrupt handler.  The interrupt controller requires
firmware like the CP.  This firmware must be installed and
accessble to the firmware loader for interrupts to function.

MSIs don't seem to work on my RS780.  They work fine on all
my discrete cards.  I'm not sure about other RS780s or
RS880s.  I've disabled MSIs on RS780 and RS880, but it would
probably be worth checking on some other systems.

v2 - fix some checkpatch.pl problems;
     re-read the disp int status reg if we restart the ih;

v3 - remove the irq handler if r600_irq_init() fails;
     remove spinlock in r600_ih_ring_fini();
     move ih rb overflow check to r600_get_ih_wptr();
     move irq ack to separate function;
Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/radeon/r600_blit_kms.c

@@ -569,9 +569,9 @@ int r600_blit_prepare_copy(struct radeon_device *rdev, int size_bytes)
 	ring_size = num_loops * dwords_per_loop;
 	/* set default  + shaders */
 	ring_size += 40; /* shaders + def state */
-	ring_size += 3; /* fence emit for VB IB */
+	ring_size += 5; /* fence emit for VB IB */
 	ring_size += 5; /* done copy */
-	ring_size += 3; /* fence emit for done copy */
+	ring_size += 5; /* fence emit for done copy */
 	r = radeon_ring_lock(rdev, ring_size);
 	WARN_ON(r);
 

drivers/gpu/drm/radeon/radeon.h

@@ -399,6 +399,23 @@ struct radeon_cp {
 	bool			ready;
 };
 
+/*
+ * R6xx+ IH ring
+ */
+struct r600_ih {
+	struct radeon_object	*ring_obj;
+	volatile uint32_t	*ring;
+	unsigned		rptr;
+	unsigned		wptr;
+	unsigned		wptr_old;
+	unsigned		ring_size;
+	uint64_t		gpu_addr;
+	uint32_t		align_mask;
+	uint32_t		ptr_mask;
+	spinlock_t              lock;
+	bool                    enabled;
+};
+
 struct r600_blit {
 	struct radeon_object	*shader_obj;
 	u64 shader_gpu_addr;
@@ -792,8 +809,10 @@ struct radeon_device {
 	struct radeon_surface_reg surface_regs[RADEON_GEM_MAX_SURFACES];
 	const struct firmware *me_fw;	/* all family ME firmware */
 	const struct firmware *pfp_fw;	/* r6/700 PFP firmware */
+	const struct firmware *rlc_fw;	/* r6/700 RLC firmware */
 	struct r600_blit r600_blit;
 	int msi_enabled; /* msi enabled */
+	struct r600_ih ih; /* r6/700 interrupt ring */
 };
 
 int radeon_device_init(struct radeon_device *rdev,
@@ -1108,7 +1127,12 @@ extern void r600_wb_disable(struct radeon_device *rdev);
 extern void r600_scratch_init(struct radeon_device *rdev);
 extern int r600_blit_init(struct radeon_device *rdev);
 extern void r600_blit_fini(struct radeon_device *rdev);
-extern int r600_cp_init_microcode(struct radeon_device *rdev);
+extern int r600_init_microcode(struct radeon_device *rdev);
 extern int r600_gpu_reset(struct radeon_device *rdev);
+/* r600 irq */
+extern int r600_irq_init(struct radeon_device *rdev);
+extern void r600_irq_fini(struct radeon_device *rdev);
+extern void r600_ih_ring_init(struct radeon_device *rdev, unsigned ring_size);
+extern int r600_irq_set(struct radeon_device *rdev);
 
 #endif

drivers/gpu/drm/radeon/radeon_asic.h

@@ -480,6 +480,7 @@ static struct radeon_asic r600_asic = {
 	.ring_ib_execute = &r600_ring_ib_execute,
 	.irq_set = &r600_irq_set,
 	.irq_process = &r600_irq_process,
+	.get_vblank_counter = &rs600_get_vblank_counter,
 	.fence_ring_emit = &r600_fence_ring_emit,
 	.cs_parse = &r600_cs_parse,
 	.copy_blit = &r600_copy_blit,
@@ -520,6 +521,7 @@ static struct radeon_asic rv770_asic = {
 	.ring_ib_execute = &r600_ring_ib_execute,
 	.irq_set = &r600_irq_set,
 	.irq_process = &r600_irq_process,
+	.get_vblank_counter = &rs600_get_vblank_counter,
 	.fence_ring_emit = &r600_fence_ring_emit,
 	.cs_parse = &r600_cs_parse,
 	.copy_blit = &r600_copy_blit,

drivers/gpu/drm/radeon/radeon_device.c

@@ -562,6 +562,8 @@ int radeon_device_init(struct radeon_device *rdev,
 	mutex_init(&rdev->cs_mutex);
 	mutex_init(&rdev->ib_pool.mutex);
 	mutex_init(&rdev->cp.mutex);
+	if (rdev->family >= CHIP_R600)
+		spin_lock_init(&rdev->ih.lock);
 	rwlock_init(&rdev->fence_drv.lock);
 	INIT_LIST_HEAD(&rdev->gem.objects);
 

drivers/gpu/drm/radeon/radeon_drv.h

@@ -1104,7 +1104,6 @@ extern u32 radeon_get_scratch(drm_radeon_private_t *dev_priv, int index);
 #       define R600_IT_WAIT_REG_MEM             0x00003C00
 #       define R600_IT_MEM_WRITE                0x00003D00
 #       define R600_IT_INDIRECT_BUFFER          0x00003200
-#       define R600_IT_CP_INTERRUPT             0x00004000
 #       define R600_IT_SURFACE_SYNC             0x00004300
 #              define R600_CB0_DEST_BASE_ENA    (1 << 6)
 #              define R600_TC_ACTION_ENA        (1 << 23)

drivers/gpu/drm/radeon/radeon_fence.c

@@ -168,37 +168,6 @@ bool radeon_fence_signaled(struct radeon_fence *fence)
 	return signaled;
 }
 
-int r600_fence_wait(struct radeon_fence *fence,  bool intr, bool lazy)
-{
-	struct radeon_device *rdev;
-	int ret = 0;
-
-	rdev = fence->rdev;
-
-	__set_current_state(intr ? TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE);
-
-	while (1) {
-		if (radeon_fence_signaled(fence))
-			break;
-
-		if (time_after_eq(jiffies, fence->timeout)) {
-			ret = -EBUSY;
-			break;
-		}
-
-		if (lazy)
-			schedule_timeout(1);
-
-		if (intr && signal_pending(current)) {
-			ret = -ERESTARTSYS;
-			break;
-		}
-	}
-	__set_current_state(TASK_RUNNING);
-	return ret;
-}
-
-
 int radeon_fence_wait(struct radeon_fence *fence, bool intr)
 {
 	struct radeon_device *rdev;
@@ -216,13 +185,6 @@ int radeon_fence_wait(struct radeon_fence *fence, bool intr)
 		return 0;
 	}
 
-	if (rdev->family >= CHIP_R600) {
-		r = r600_fence_wait(fence, intr, 0);
-		if (r == -ERESTARTSYS)
-			return -EBUSY;
-		return r;
-	}
-
 retry:
 	cur_jiffies = jiffies;
 	timeout = HZ / 100;

drivers/gpu/drm/radeon/radeon_irq_kms.c

@@ -94,10 +94,18 @@ int radeon_irq_kms_init(struct radeon_device *rdev)
 	}
 	/* enable msi */
 	rdev->msi_enabled = 0;
-	if (rdev->family >= CHIP_RV380) {
+	/* MSIs don't seem to work on my rs780;
+	 * not sure about rs880 or other rs780s.
+	 * Needs more investigation.
+	 */
+	if ((rdev->family >= CHIP_RV380) &&
+	    (rdev->family != CHIP_RS780) &&
+	    (rdev->family != CHIP_RS880)) {
 		int ret = pci_enable_msi(rdev->pdev);
-		if (!ret)
+		if (!ret) {
 			rdev->msi_enabled = 1;
+			DRM_INFO("radeon: using MSI.\n");
+		}
 	}
 	drm_irq_install(rdev->ddev);
 	rdev->irq.installed = true;

drivers/gpu/drm/radeon/rv770.c

@@ -887,6 +887,16 @@ static int rv770_startup(struct radeon_device *rdev)
 		return r;
 	}
 
+	/* Enable IRQ */
+	rdev->irq.sw_int = true;
+	r = r600_irq_init(rdev);
+	if (r) {
+		DRM_ERROR("radeon: IH init failed (%d).\n", r);
+		radeon_irq_kms_fini(rdev);
+		return r;
+	}
+	r600_irq_set(rdev);
+
 	r = radeon_ring_init(rdev, rdev->cp.ring_size);
 	if (r)
 		return r;
@@ -1005,11 +1015,19 @@ int rv770_init(struct radeon_device *rdev)
 	r = radeon_object_init(rdev);
 	if (r)
 		return r;
+
+	r = radeon_irq_kms_init(rdev);
+	if (r)
+		return r;
+
 	rdev->cp.ring_obj = NULL;
 	r600_ring_init(rdev, 1024 * 1024);
 
-	if (!rdev->me_fw || !rdev->pfp_fw) {
-		r = r600_cp_init_microcode(rdev);
+	rdev->ih.ring_obj = NULL;
+	r600_ih_ring_init(rdev, 64 * 1024);
+
+	if (!rdev->me_fw || !rdev->pfp_fw || !rdev->rlc_fw) {
+		r = r600_init_microcode(rdev);
 		if (r) {
 			DRM_ERROR("Failed to load firmware!\n");
 			return r;
@@ -1055,6 +1073,8 @@ void rv770_fini(struct radeon_device *rdev)
 	rv770_suspend(rdev);
 
 	r600_blit_fini(rdev);
+	r600_irq_fini(rdev);
+	radeon_irq_kms_fini(rdev);
 	radeon_ring_fini(rdev);
 	r600_wb_fini(rdev);
 	rv770_pcie_gart_fini(rdev);