xref: /openbmc/linux/drivers/gpu/drm/vc4/vc4_irq.c (revision fb960bd2)
1 /*
2  * Copyright © 2014 Broadcom
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a
5  * copy of this software and associated documentation files (the "Software"),
6  * to deal in the Software without restriction, including without limitation
7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8  * and/or sell copies of the Software, and to permit persons to whom the
9  * Software is furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice (including the next
12  * paragraph) shall be included in all copies or substantial portions of the
13  * Software.
14  *
15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
18  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
20  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
21  * IN THE SOFTWARE.
22  */
23 
24 /**
25  * DOC: Interrupt management for the V3D engine
26  *
27  * We have an interrupt status register (V3D_INTCTL) which reports
28  * interrupts, and where writing 1 bits clears those interrupts.
29  * There are also a pair of interrupt registers
30  * (V3D_INTENA/V3D_INTDIS) where writing a 1 to their bits enables or
31  * disables that specific interrupt, and 0s written are ignored
32  * (reading either one returns the set of enabled interrupts).
33  *
34  * When we take a binning flush done interrupt, we need to submit the
35  * next frame for binning and move the finished frame to the render
36  * thread.
37  *
38  * When we take a render frame interrupt, we need to wake the
39  * processes waiting for some frame to be done, and get the next frame
40  * submitted ASAP (so the hardware doesn't sit idle when there's work
41  * to do).
42  *
43  * When we take the binner out of memory interrupt, we need to
44  * allocate some new memory and pass it to the binner so that the
45  * current job can make progress.
46  */
47 
48 #include "vc4_drv.h"
49 #include "vc4_regs.h"
50 
51 #define V3D_DRIVER_IRQS (V3D_INT_OUTOMEM | \
52 			 V3D_INT_FLDONE | \
53 			 V3D_INT_FRDONE)
54 
55 DECLARE_WAIT_QUEUE_HEAD(render_wait);
56 
57 static void
58 vc4_overflow_mem_work(struct work_struct *work)
59 {
60 	struct vc4_dev *vc4 =
61 		container_of(work, struct vc4_dev, overflow_mem_work);
62 	struct vc4_bo *bo = vc4->bin_bo;
63 	int bin_bo_slot;
64 	struct vc4_exec_info *exec;
65 	unsigned long irqflags;
66 
67 	bin_bo_slot = vc4_v3d_get_bin_slot(vc4);
68 	if (bin_bo_slot < 0) {
69 		DRM_ERROR("Couldn't allocate binner overflow mem\n");
70 		return;
71 	}
72 
73 	spin_lock_irqsave(&vc4->job_lock, irqflags);
74 
75 	if (vc4->bin_alloc_overflow) {
76 		/* If we had overflow memory allocated previously,
77 		 * then that chunk will free when the current bin job
78 		 * is done.  If we don't have a bin job running, then
79 		 * the chunk will be done whenever the list of render
80 		 * jobs has drained.
81 		 */
82 		exec = vc4_first_bin_job(vc4);
83 		if (!exec)
84 			exec = vc4_last_render_job(vc4);
85 		if (exec) {
86 			exec->bin_slots |= vc4->bin_alloc_overflow;
87 		} else {
88 			/* There's nothing queued in the hardware, so
89 			 * the old slot is free immediately.
90 			 */
91 			vc4->bin_alloc_used &= ~vc4->bin_alloc_overflow;
92 		}
93 	}
94 	vc4->bin_alloc_overflow = BIT(bin_bo_slot);
95 
96 	V3D_WRITE(V3D_BPOA, bo->base.paddr + bin_bo_slot * vc4->bin_alloc_size);
97 	V3D_WRITE(V3D_BPOS, bo->base.base.size);
98 	V3D_WRITE(V3D_INTCTL, V3D_INT_OUTOMEM);
99 	V3D_WRITE(V3D_INTENA, V3D_INT_OUTOMEM);
100 	spin_unlock_irqrestore(&vc4->job_lock, irqflags);
101 }
102 
103 static void
104 vc4_irq_finish_bin_job(struct drm_device *dev)
105 {
106 	struct vc4_dev *vc4 = to_vc4_dev(dev);
107 	struct vc4_exec_info *exec = vc4_first_bin_job(vc4);
108 
109 	if (!exec)
110 		return;
111 
112 	vc4_move_job_to_render(dev, exec);
113 	vc4_submit_next_bin_job(dev);
114 }
115 
116 static void
117 vc4_cancel_bin_job(struct drm_device *dev)
118 {
119 	struct vc4_dev *vc4 = to_vc4_dev(dev);
120 	struct vc4_exec_info *exec = vc4_first_bin_job(vc4);
121 
122 	if (!exec)
123 		return;
124 
125 	list_move_tail(&exec->head, &vc4->bin_job_list);
126 	vc4_submit_next_bin_job(dev);
127 }
128 
129 static void
130 vc4_irq_finish_render_job(struct drm_device *dev)
131 {
132 	struct vc4_dev *vc4 = to_vc4_dev(dev);
133 	struct vc4_exec_info *exec = vc4_first_render_job(vc4);
134 
135 	if (!exec)
136 		return;
137 
138 	vc4->finished_seqno++;
139 	list_move_tail(&exec->head, &vc4->job_done_list);
140 	if (exec->fence) {
141 		dma_fence_signal_locked(exec->fence);
142 		exec->fence = NULL;
143 	}
144 	vc4_submit_next_render_job(dev);
145 
146 	wake_up_all(&vc4->job_wait_queue);
147 	schedule_work(&vc4->job_done_work);
148 }
149 
150 irqreturn_t
151 vc4_irq(int irq, void *arg)
152 {
153 	struct drm_device *dev = arg;
154 	struct vc4_dev *vc4 = to_vc4_dev(dev);
155 	uint32_t intctl;
156 	irqreturn_t status = IRQ_NONE;
157 
158 	barrier();
159 	intctl = V3D_READ(V3D_INTCTL);
160 
161 	/* Acknowledge the interrupts we're handling here. The binner
162 	 * last flush / render frame done interrupt will be cleared,
163 	 * while OUTOMEM will stay high until the underlying cause is
164 	 * cleared.
165 	 */
166 	V3D_WRITE(V3D_INTCTL, intctl);
167 
168 	if (intctl & V3D_INT_OUTOMEM) {
169 		/* Disable OUTOMEM until the work is done. */
170 		V3D_WRITE(V3D_INTDIS, V3D_INT_OUTOMEM);
171 		schedule_work(&vc4->overflow_mem_work);
172 		status = IRQ_HANDLED;
173 	}
174 
175 	if (intctl & V3D_INT_FLDONE) {
176 		spin_lock(&vc4->job_lock);
177 		vc4_irq_finish_bin_job(dev);
178 		spin_unlock(&vc4->job_lock);
179 		status = IRQ_HANDLED;
180 	}
181 
182 	if (intctl & V3D_INT_FRDONE) {
183 		spin_lock(&vc4->job_lock);
184 		vc4_irq_finish_render_job(dev);
185 		spin_unlock(&vc4->job_lock);
186 		status = IRQ_HANDLED;
187 	}
188 
189 	return status;
190 }
191 
192 void
193 vc4_irq_preinstall(struct drm_device *dev)
194 {
195 	struct vc4_dev *vc4 = to_vc4_dev(dev);
196 
197 	init_waitqueue_head(&vc4->job_wait_queue);
198 	INIT_WORK(&vc4->overflow_mem_work, vc4_overflow_mem_work);
199 
200 	/* Clear any pending interrupts someone might have left around
201 	 * for us.
202 	 */
203 	V3D_WRITE(V3D_INTCTL, V3D_DRIVER_IRQS);
204 }
205 
206 int
207 vc4_irq_postinstall(struct drm_device *dev)
208 {
209 	struct vc4_dev *vc4 = to_vc4_dev(dev);
210 
211 	/* Undo the effects of a previous vc4_irq_uninstall. */
212 	enable_irq(dev->irq);
213 
214 	/* Enable both the render done and out of memory interrupts. */
215 	V3D_WRITE(V3D_INTENA, V3D_DRIVER_IRQS);
216 
217 	return 0;
218 }
219 
220 void
221 vc4_irq_uninstall(struct drm_device *dev)
222 {
223 	struct vc4_dev *vc4 = to_vc4_dev(dev);
224 
225 	/* Disable sending interrupts for our driver's IRQs. */
226 	V3D_WRITE(V3D_INTDIS, V3D_DRIVER_IRQS);
227 
228 	/* Clear any pending interrupts we might have left. */
229 	V3D_WRITE(V3D_INTCTL, V3D_DRIVER_IRQS);
230 
231 	/* Finish any interrupt handler still in flight. */
232 	disable_irq(dev->irq);
233 
234 	cancel_work_sync(&vc4->overflow_mem_work);
235 }
236 
237 /** Reinitializes interrupt registers when a GPU reset is performed. */
238 void vc4_irq_reset(struct drm_device *dev)
239 {
240 	struct vc4_dev *vc4 = to_vc4_dev(dev);
241 	unsigned long irqflags;
242 
243 	/* Acknowledge any stale IRQs. */
244 	V3D_WRITE(V3D_INTCTL, V3D_DRIVER_IRQS);
245 
246 	/*
247 	 * Turn all our interrupts on.  Binner out of memory is the
248 	 * only one we expect to trigger at this point, since we've
249 	 * just come from poweron and haven't supplied any overflow
250 	 * memory yet.
251 	 */
252 	V3D_WRITE(V3D_INTENA, V3D_DRIVER_IRQS);
253 
254 	spin_lock_irqsave(&vc4->job_lock, irqflags);
255 	vc4_cancel_bin_job(dev);
256 	vc4_irq_finish_render_job(dev);
257 	spin_unlock_irqrestore(&vc4->job_lock, irqflags);
258 }
259