1 // SPDX-License-Identifier: GPL-2.0 OR MIT
2 /**************************************************************************
3  *
4  * Copyright 2009-2015 VMware, Inc., Palo Alto, CA., USA
5  *
6  * Permission is hereby granted, free of charge, to any person obtaining a
7  * copy of this software and associated documentation files (the
8  * "Software"), to deal in the Software without restriction, including
9  * without limitation the rights to use, copy, modify, merge, publish,
10  * distribute, sub license, and/or sell copies of the Software, and to
11  * permit persons to whom the Software is furnished to do so, subject to
12  * the following conditions:
13  *
14  * The above copyright notice and this permission notice (including the
15  * next paragraph) shall be included in all copies or substantial portions
16  * of the Software.
17  *
18  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20  * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
21  * THE COPYRIGHT HOLDERS, AUTHORS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM,
22  * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
23  * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
24  * USE OR OTHER DEALINGS IN THE SOFTWARE.
25  *
26  **************************************************************************/
27 
28 #include <linux/pci.h>
29 #include <linux/sched/signal.h>
30 
31 #include "vmwgfx_drv.h"
32 
33 #define VMW_FENCE_WRAP (1 << 24)
34 
35 /**
36  * vmw_thread_fn - Deferred (process context) irq handler
37  *
38  * @irq: irq number
39  * @arg: Closure argument. Pointer to a struct drm_device cast to void *
40  *
41  * This function implements the deferred part of irq processing.
42  * The function is guaranteed to run at least once after the
43  * vmw_irq_handler has returned with IRQ_WAKE_THREAD.
44  *
45  */
46 static irqreturn_t vmw_thread_fn(int irq, void *arg)
47 {
48 	struct drm_device *dev = (struct drm_device *)arg;
49 	struct vmw_private *dev_priv = vmw_priv(dev);
50 	irqreturn_t ret = IRQ_NONE;
51 
52 	if (test_and_clear_bit(VMW_IRQTHREAD_FENCE,
53 			       dev_priv->irqthread_pending)) {
54 		vmw_fences_update(dev_priv->fman);
55 		wake_up_all(&dev_priv->fence_queue);
56 		ret = IRQ_HANDLED;
57 	}
58 
59 	if (test_and_clear_bit(VMW_IRQTHREAD_CMDBUF,
60 			       dev_priv->irqthread_pending)) {
61 		vmw_cmdbuf_irqthread(dev_priv->cman);
62 		ret = IRQ_HANDLED;
63 	}
64 
65 	return ret;
66 }
67 
68 /**
69  * vmw_irq_handler: irq handler
70  *
71  * @irq: irq number
72  * @arg: Closure argument. Pointer to a struct drm_device cast to void *
73  *
74  * This function implements the quick part of irq processing.
75  * The function performs fast actions like clearing the device interrupt
76  * flags and also reasonably quick actions like waking processes waiting for
77  * FIFO space. Other IRQ actions are deferred to the IRQ thread.
78  */
79 static irqreturn_t vmw_irq_handler(int irq, void *arg)
80 {
81 	struct drm_device *dev = (struct drm_device *)arg;
82 	struct vmw_private *dev_priv = vmw_priv(dev);
83 	uint32_t status, masked_status;
84 	irqreturn_t ret = IRQ_HANDLED;
85 
86 	status = vmw_irq_status_read(dev_priv);
87 	masked_status = status & READ_ONCE(dev_priv->irq_mask);
88 
89 	if (likely(status))
90 		vmw_irq_status_write(dev_priv, status);
91 
92 	if (!status)
93 		return IRQ_NONE;
94 
95 	if (masked_status & SVGA_IRQFLAG_FIFO_PROGRESS)
96 		wake_up_all(&dev_priv->fifo_queue);
97 
98 	if ((masked_status & (SVGA_IRQFLAG_ANY_FENCE |
99 			      SVGA_IRQFLAG_FENCE_GOAL)) &&
100 	    !test_and_set_bit(VMW_IRQTHREAD_FENCE, dev_priv->irqthread_pending))
101 		ret = IRQ_WAKE_THREAD;
102 
103 	if ((masked_status & (SVGA_IRQFLAG_COMMAND_BUFFER |
104 			      SVGA_IRQFLAG_ERROR)) &&
105 	    !test_and_set_bit(VMW_IRQTHREAD_CMDBUF,
106 			      dev_priv->irqthread_pending))
107 		ret = IRQ_WAKE_THREAD;
108 
109 	return ret;
110 }
111 
112 static bool vmw_fifo_idle(struct vmw_private *dev_priv, uint32_t seqno)
113 {
114 
115 	return (vmw_read(dev_priv, SVGA_REG_BUSY) == 0);
116 }
117 
118 void vmw_update_seqno(struct vmw_private *dev_priv)
119 {
120 	uint32_t seqno = vmw_fence_read(dev_priv);
121 
122 	if (dev_priv->last_read_seqno != seqno) {
123 		dev_priv->last_read_seqno = seqno;
124 		vmw_fences_update(dev_priv->fman);
125 	}
126 }
127 
128 bool vmw_seqno_passed(struct vmw_private *dev_priv,
129 			 uint32_t seqno)
130 {
131 	bool ret;
132 
133 	if (likely(dev_priv->last_read_seqno - seqno < VMW_FENCE_WRAP))
134 		return true;
135 
136 	vmw_update_seqno(dev_priv);
137 	if (likely(dev_priv->last_read_seqno - seqno < VMW_FENCE_WRAP))
138 		return true;
139 
140 	if (!(vmw_fifo_caps(dev_priv) & SVGA_FIFO_CAP_FENCE) &&
141 	    vmw_fifo_idle(dev_priv, seqno))
142 		return true;
143 
144 	/**
145 	 * Then check if the seqno is higher than what we've actually
146 	 * emitted. Then the fence is stale and signaled.
147 	 */
148 
149 	ret = ((atomic_read(&dev_priv->marker_seq) - seqno)
150 	       > VMW_FENCE_WRAP);
151 
152 	return ret;
153 }
154 
155 int vmw_fallback_wait(struct vmw_private *dev_priv,
156 		      bool lazy,
157 		      bool fifo_idle,
158 		      uint32_t seqno,
159 		      bool interruptible,
160 		      unsigned long timeout)
161 {
162 	struct vmw_fifo_state *fifo_state = dev_priv->fifo;
163 
164 	uint32_t count = 0;
165 	uint32_t signal_seq;
166 	int ret;
167 	unsigned long end_jiffies = jiffies + timeout;
168 	bool (*wait_condition)(struct vmw_private *, uint32_t);
169 	DEFINE_WAIT(__wait);
170 
171 	wait_condition = (fifo_idle) ? &vmw_fifo_idle :
172 		&vmw_seqno_passed;
173 
174 	/**
175 	 * Block command submission while waiting for idle.
176 	 */
177 
178 	if (fifo_idle) {
179 		down_read(&fifo_state->rwsem);
180 		if (dev_priv->cman) {
181 			ret = vmw_cmdbuf_idle(dev_priv->cman, interruptible,
182 					      10*HZ);
183 			if (ret)
184 				goto out_err;
185 		}
186 	}
187 
188 	signal_seq = atomic_read(&dev_priv->marker_seq);
189 	ret = 0;
190 
191 	for (;;) {
192 		prepare_to_wait(&dev_priv->fence_queue, &__wait,
193 				(interruptible) ?
194 				TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE);
195 		if (wait_condition(dev_priv, seqno))
196 			break;
197 		if (time_after_eq(jiffies, end_jiffies)) {
198 			DRM_ERROR("SVGA device lockup.\n");
199 			break;
200 		}
201 		if (lazy)
202 			schedule_timeout(1);
203 		else if ((++count & 0x0F) == 0) {
204 			/**
205 			 * FIXME: Use schedule_hr_timeout here for
206 			 * newer kernels and lower CPU utilization.
207 			 */
208 
209 			__set_current_state(TASK_RUNNING);
210 			schedule();
211 			__set_current_state((interruptible) ?
212 					    TASK_INTERRUPTIBLE :
213 					    TASK_UNINTERRUPTIBLE);
214 		}
215 		if (interruptible && signal_pending(current)) {
216 			ret = -ERESTARTSYS;
217 			break;
218 		}
219 	}
220 	finish_wait(&dev_priv->fence_queue, &__wait);
221 	if (ret == 0 && fifo_idle)
222 		vmw_fence_write(dev_priv, signal_seq);
223 
224 	wake_up_all(&dev_priv->fence_queue);
225 out_err:
226 	if (fifo_idle)
227 		up_read(&fifo_state->rwsem);
228 
229 	return ret;
230 }
231 
232 void vmw_generic_waiter_add(struct vmw_private *dev_priv,
233 			    u32 flag, int *waiter_count)
234 {
235 	spin_lock_bh(&dev_priv->waiter_lock);
236 	if ((*waiter_count)++ == 0) {
237 		vmw_irq_status_write(dev_priv, flag);
238 		dev_priv->irq_mask |= flag;
239 		vmw_write(dev_priv, SVGA_REG_IRQMASK, dev_priv->irq_mask);
240 	}
241 	spin_unlock_bh(&dev_priv->waiter_lock);
242 }
243 
244 void vmw_generic_waiter_remove(struct vmw_private *dev_priv,
245 			       u32 flag, int *waiter_count)
246 {
247 	spin_lock_bh(&dev_priv->waiter_lock);
248 	if (--(*waiter_count) == 0) {
249 		dev_priv->irq_mask &= ~flag;
250 		vmw_write(dev_priv, SVGA_REG_IRQMASK, dev_priv->irq_mask);
251 	}
252 	spin_unlock_bh(&dev_priv->waiter_lock);
253 }
254 
255 void vmw_seqno_waiter_add(struct vmw_private *dev_priv)
256 {
257 	vmw_generic_waiter_add(dev_priv, SVGA_IRQFLAG_ANY_FENCE,
258 			       &dev_priv->fence_queue_waiters);
259 }
260 
261 void vmw_seqno_waiter_remove(struct vmw_private *dev_priv)
262 {
263 	vmw_generic_waiter_remove(dev_priv, SVGA_IRQFLAG_ANY_FENCE,
264 				  &dev_priv->fence_queue_waiters);
265 }
266 
267 void vmw_goal_waiter_add(struct vmw_private *dev_priv)
268 {
269 	vmw_generic_waiter_add(dev_priv, SVGA_IRQFLAG_FENCE_GOAL,
270 			       &dev_priv->goal_queue_waiters);
271 }
272 
273 void vmw_goal_waiter_remove(struct vmw_private *dev_priv)
274 {
275 	vmw_generic_waiter_remove(dev_priv, SVGA_IRQFLAG_FENCE_GOAL,
276 				  &dev_priv->goal_queue_waiters);
277 }
278 
279 static void vmw_irq_preinstall(struct drm_device *dev)
280 {
281 	struct vmw_private *dev_priv = vmw_priv(dev);
282 	uint32_t status;
283 
284 	status = vmw_irq_status_read(dev_priv);
285 	vmw_irq_status_write(dev_priv, status);
286 }
287 
288 void vmw_irq_uninstall(struct drm_device *dev)
289 {
290 	struct vmw_private *dev_priv = vmw_priv(dev);
291 	struct pci_dev *pdev = to_pci_dev(dev->dev);
292 	uint32_t status;
293 
294 	if (!(dev_priv->capabilities & SVGA_CAP_IRQMASK))
295 		return;
296 
297 	vmw_write(dev_priv, SVGA_REG_IRQMASK, 0);
298 
299 	status = vmw_irq_status_read(dev_priv);
300 	vmw_irq_status_write(dev_priv, status);
301 
302 	free_irq(pdev->irq, dev);
303 }
304 
305 /**
306  * vmw_irq_install - Install the irq handlers
307  *
308  * @dev:  Pointer to the drm device.
309  * @irq:  The irq number.
310  * Return:  Zero if successful. Negative number otherwise.
311  */
312 int vmw_irq_install(struct drm_device *dev, int irq)
313 {
314 	vmw_irq_preinstall(dev);
315 
316 	return request_threaded_irq(irq, vmw_irq_handler, vmw_thread_fn,
317 				    IRQF_SHARED, VMWGFX_DRIVER_NAME, dev);
318 }
319