1// SPDX-License-Identifier: MIT
2/*
3 * Copyright © 2022 Intel Corporation
4 */
5
6#include "xe_wait_user_fence.h"
7
8#include <drm/drm_device.h>
9#include <drm/drm_file.h>
10#include <drm/drm_utils.h>
11#include <uapi/drm/xe_drm.h>
12
13#include "xe_device.h"
14#include "xe_gt.h"
15#include "xe_macros.h"
16#include "xe_exec_queue.h"
17
18static int do_compare(u64 addr, u64 value, u64 mask, u16 op)
19{
20 u64 rvalue;
21 int err;
22 bool passed;
23
24 err = copy_from_user(to: &rvalue, u64_to_user_ptr(addr), n: sizeof(rvalue));
25 if (err)
26 return -EFAULT;
27
28 switch (op) {
29 case DRM_XE_UFENCE_WAIT_OP_EQ:
30 passed = (rvalue & mask) == (value & mask);
31 break;
32 case DRM_XE_UFENCE_WAIT_OP_NEQ:
33 passed = (rvalue & mask) != (value & mask);
34 break;
35 case DRM_XE_UFENCE_WAIT_OP_GT:
36 passed = (rvalue & mask) > (value & mask);
37 break;
38 case DRM_XE_UFENCE_WAIT_OP_GTE:
39 passed = (rvalue & mask) >= (value & mask);
40 break;
41 case DRM_XE_UFENCE_WAIT_OP_LT:
42 passed = (rvalue & mask) < (value & mask);
43 break;
44 case DRM_XE_UFENCE_WAIT_OP_LTE:
45 passed = (rvalue & mask) <= (value & mask);
46 break;
47 default:
48 XE_WARN_ON("Not possible");
49 return -EINVAL;
50 }
51
52 return passed ? 0 : 1;
53}
54
55#define VALID_FLAGS DRM_XE_UFENCE_WAIT_FLAG_ABSTIME
56#define MAX_OP DRM_XE_UFENCE_WAIT_OP_LTE
57
58static long to_jiffies_timeout(struct xe_device *xe,
59 struct drm_xe_wait_user_fence *args)
60{
61 unsigned long long t;
62 long timeout;
63
64 /*
65 * For negative timeout we want to wait "forever" by setting
66 * MAX_SCHEDULE_TIMEOUT. But we have to assign this value also
67 * to args->timeout to avoid being zeroed on the signal delivery
68 * (see arithmetics after wait).
69 */
70 if (args->timeout < 0) {
71 args->timeout = MAX_SCHEDULE_TIMEOUT;
72 return MAX_SCHEDULE_TIMEOUT;
73 }
74
75 if (args->timeout == 0)
76 return 0;
77
78 /*
79 * Save the timeout to an u64 variable because nsecs_to_jiffies
80 * might return a value that overflows s32 variable.
81 */
82 if (args->flags & DRM_XE_UFENCE_WAIT_FLAG_ABSTIME)
83 t = drm_timeout_abs_to_jiffies(timeout_nsec: args->timeout);
84 else
85 t = nsecs_to_jiffies(n: args->timeout);
86
87 /*
88 * Anything greater then MAX_SCHEDULE_TIMEOUT is meaningless,
89 * also we don't want to cap it at MAX_SCHEDULE_TIMEOUT because
90 * apparently user doesn't mean to wait forever, otherwise the
91 * args->timeout should have been set to a negative value.
92 */
93 if (t > MAX_SCHEDULE_TIMEOUT)
94 timeout = MAX_SCHEDULE_TIMEOUT - 1;
95 else
96 timeout = t;
97
98 return timeout ?: 1;
99}
100
101int xe_wait_user_fence_ioctl(struct drm_device *dev, void *data,
102 struct drm_file *file)
103{
104 struct xe_device *xe = to_xe_device(dev);
105 struct xe_file *xef = to_xe_file(file);
106 DEFINE_WAIT_FUNC(w_wait, woken_wake_function);
107 struct drm_xe_wait_user_fence *args = data;
108 struct xe_exec_queue *q = NULL;
109 u64 addr = args->addr;
110 int err = 0;
111 long timeout;
112 ktime_t start;
113
114 if (XE_IOCTL_DBG(xe, args->extensions) || XE_IOCTL_DBG(xe, args->pad) ||
115 XE_IOCTL_DBG(xe, args->pad2) ||
116 XE_IOCTL_DBG(xe, args->reserved[0] || args->reserved[1]))
117 return -EINVAL;
118
119 if (XE_IOCTL_DBG(xe, args->flags & ~VALID_FLAGS))
120 return -EINVAL;
121
122 if (XE_IOCTL_DBG(xe, args->op > MAX_OP))
123 return -EINVAL;
124
125 if (XE_IOCTL_DBG(xe, addr & 0x7))
126 return -EINVAL;
127
128 if (args->exec_queue_id) {
129 q = xe_exec_queue_lookup(xef, id: args->exec_queue_id);
130 if (XE_IOCTL_DBG(xe, !q))
131 return -ENOENT;
132 }
133
134 timeout = to_jiffies_timeout(xe, args);
135
136 start = ktime_get();
137
138 add_wait_queue(wq_head: &xe->ufence_wq, wq_entry: &w_wait);
139 for (;;) {
140 err = do_compare(addr, value: args->value, mask: args->mask, op: args->op);
141 if (err <= 0)
142 break;
143
144 if (signal_pending(current)) {
145 err = -ERESTARTSYS;
146 break;
147 }
148
149 if (q) {
150 if (q->ops->reset_status(q)) {
151 drm_info(&xe->drm, "exec queue reset detected\n");
152 err = -EIO;
153 break;
154 }
155 }
156
157 if (!timeout) {
158 LNL_FLUSH_WORKQUEUE(xe->ordered_wq);
159 err = do_compare(addr, value: args->value, mask: args->mask,
160 op: args->op);
161 if (err <= 0) {
162 drm_dbg(&xe->drm, "LNL_FLUSH_WORKQUEUE resolved ufence timeout\n");
163 break;
164 }
165 err = -ETIME;
166 break;
167 }
168
169 timeout = wait_woken(wq_entry: &w_wait, TASK_INTERRUPTIBLE, timeout);
170 }
171 remove_wait_queue(wq_head: &xe->ufence_wq, wq_entry: &w_wait);
172
173 if (!(args->flags & DRM_XE_UFENCE_WAIT_FLAG_ABSTIME)) {
174 args->timeout -= ktime_to_ns(ktime_sub(ktime_get(), start));
175 if (args->timeout < 0)
176 args->timeout = 0;
177 }
178
179 if (q)
180 xe_exec_queue_put(q);
181
182 return err;
183}
184

source code of linux/drivers/gpu/drm/xe/xe_wait_user_fence.c