xref: /linux/drivers/gpu/drm/xe/xe_sriov_pf.c (revision d30c1683aaecb93d2ab95685dc4300a33d3cea7a)
1 // SPDX-License-Identifier: MIT
2 /*
3  * Copyright © 2023-2024 Intel Corporation
4  */
5 
6 #include <linux/debugfs.h>
7 #include <drm/drm_debugfs.h>
8 #include <drm/drm_managed.h>
9 
10 #include "xe_assert.h"
11 #include "xe_configfs.h"
12 #include "xe_device.h"
13 #include "xe_gt_sriov_pf.h"
14 #include "xe_module.h"
15 #include "xe_sriov.h"
16 #include "xe_sriov_pf.h"
17 #include "xe_sriov_pf_helpers.h"
18 #include "xe_sriov_pf_migration.h"
19 #include "xe_sriov_pf_service.h"
20 #include "xe_sriov_pf_sysfs.h"
21 #include "xe_sriov_printk.h"
22 
23 static unsigned int wanted_max_vfs(struct xe_device *xe)
24 {
25 	if (IS_ENABLED(CONFIG_CONFIGFS_FS))
26 		return xe_configfs_get_max_vfs(to_pci_dev(xe->drm.dev));
27 	return xe_modparam.max_vfs;
28 }
29 
30 static int pf_reduce_totalvfs(struct xe_device *xe, int limit)
31 {
32 	struct device *dev = xe->drm.dev;
33 	struct pci_dev *pdev = to_pci_dev(dev);
34 	int err;
35 
36 	err = pci_sriov_set_totalvfs(pdev, limit);
37 	if (err)
38 		xe_sriov_notice(xe, "Failed to set number of VFs to %d (%pe)\n",
39 				limit, ERR_PTR(err));
40 	return err;
41 }
42 
43 static bool pf_continue_as_native(struct xe_device *xe, const char *why)
44 {
45 	xe_sriov_dbg(xe, "%s, continuing as native\n", why);
46 	pf_reduce_totalvfs(xe, 0);
47 	return false;
48 }
49 
50 /**
51  * xe_sriov_pf_readiness - Check if PF functionality can be enabled.
52  * @xe: the &xe_device to check
53  *
54  * This function is called as part of the SR-IOV probe to validate if all
55  * PF prerequisites are satisfied and we can continue with enabling PF mode.
56  *
57  * Return: true if the PF mode can be turned on.
58  */
59 bool xe_sriov_pf_readiness(struct xe_device *xe)
60 {
61 	struct device *dev = xe->drm.dev;
62 	struct pci_dev *pdev = to_pci_dev(dev);
63 	int totalvfs = pci_sriov_get_totalvfs(pdev);
64 	int newlimit = min_t(u16, wanted_max_vfs(xe), totalvfs);
65 
66 	xe_assert(xe, totalvfs <= U16_MAX);
67 
68 	if (!dev_is_pf(dev))
69 		return false;
70 
71 	if (!xe_device_uc_enabled(xe))
72 		return pf_continue_as_native(xe, "Guc submission disabled");
73 
74 	if (!newlimit)
75 		return pf_continue_as_native(xe, "all VFs disabled");
76 
77 	pf_reduce_totalvfs(xe, newlimit);
78 
79 	xe->sriov.pf.device_total_vfs = totalvfs;
80 	xe->sriov.pf.driver_max_vfs = newlimit;
81 
82 	return true;
83 }
84 
85 /**
86  * xe_sriov_pf_init_early - Initialize SR-IOV PF specific data.
87  * @xe: the &xe_device to initialize
88  *
89  * Return: 0 on success or a negative error code on failure.
90  */
91 int xe_sriov_pf_init_early(struct xe_device *xe)
92 {
93 	int err;
94 
95 	xe_assert(xe, IS_SRIOV_PF(xe));
96 
97 	xe->sriov.pf.vfs = drmm_kcalloc(&xe->drm, 1 + xe_sriov_pf_get_totalvfs(xe),
98 					sizeof(*xe->sriov.pf.vfs), GFP_KERNEL);
99 	if (!xe->sriov.pf.vfs)
100 		return -ENOMEM;
101 
102 	err = drmm_mutex_init(&xe->drm, &xe->sriov.pf.master_lock);
103 	if (err)
104 		return err;
105 
106 	err = xe_sriov_pf_migration_init(xe);
107 	if (err)
108 		return err;
109 
110 	xe_guard_init(&xe->sriov.pf.guard_vfs_enabling, "vfs_enabling");
111 
112 	xe_sriov_pf_service_init(xe);
113 
114 	return 0;
115 }
116 
117 /**
118  * xe_sriov_pf_init_late() - Late initialization of the SR-IOV PF.
119  * @xe: the &xe_device to initialize
120  *
121  * This function can only be called on PF.
122  *
123  * Return: 0 on success or a negative error code on failure.
124  */
125 int xe_sriov_pf_init_late(struct xe_device *xe)
126 {
127 	struct xe_gt *gt;
128 	unsigned int id;
129 	int err;
130 
131 	xe_assert(xe, IS_SRIOV_PF(xe));
132 
133 	for_each_gt(gt, xe, id) {
134 		err = xe_gt_sriov_pf_init(gt);
135 		if (err)
136 			return err;
137 	}
138 
139 	err = xe_sriov_pf_sysfs_init(xe);
140 	if (err)
141 		return err;
142 
143 	return 0;
144 }
145 
146 /**
147  * xe_sriov_pf_wait_ready() - Wait until PF is ready to operate.
148  * @xe: the &xe_device to test
149  *
150  * This function can only be called on PF.
151  *
152  * Return: 0 on success or a negative error code on failure.
153  */
154 int xe_sriov_pf_wait_ready(struct xe_device *xe)
155 {
156 	struct xe_gt *gt;
157 	unsigned int id;
158 	int err;
159 
160 	if (xe_device_wedged(xe))
161 		return -ECANCELED;
162 
163 	for_each_gt(gt, xe, id) {
164 		err = xe_gt_sriov_pf_wait_ready(gt);
165 		if (err)
166 			return err;
167 	}
168 
169 	return 0;
170 }
171 
172 /**
173  * xe_sriov_pf_arm_guard() - Arm the guard for exclusive/lockdown mode.
174  * @xe: the PF &xe_device
175  * @guard: the &xe_guard to arm
176  * @lockdown: arm for lockdown(true) or exclusive(false) mode
177  * @who: the address of the new owner, or NULL if it's a caller
178  *
179  * This function can only be called on PF.
180  *
181  * It is a simple wrapper for xe_guard_arm() with additional debug
182  * messages.
183  *
184  * Return: 0 on success or a negative error code on failure.
185  */
186 int xe_sriov_pf_arm_guard(struct xe_device *xe, struct xe_guard *guard,
187 			  bool lockdown, void *who)
188 {
189 	void *new_owner = who ?: __builtin_return_address(0);
190 	int err;
191 
192 	err = xe_guard_arm(guard, lockdown, new_owner);
193 	if (err) {
194 		xe_sriov_dbg(xe, "%s/%s mode denied (%pe) last owner %ps\n",
195 			     guard->name, xe_guard_mode_str(lockdown),
196 			     ERR_PTR(err), guard->owner);
197 		return err;
198 	}
199 
200 	xe_sriov_dbg_verbose(xe, "%s/%s by %ps\n",
201 			     guard->name, xe_guard_mode_str(lockdown),
202 			     new_owner);
203 	return 0;
204 }
205 
206 /**
207  * xe_sriov_pf_disarm_guard() - Disarm the guard.
208  * @xe: the PF &xe_device
209  * @guard: the &xe_guard to disarm
210  * @lockdown: disarm from lockdown(true) or exclusive(false) mode
211  * @who: the address of the indirect owner, or NULL if it's a caller
212  *
213  * This function can only be called on PF.
214  *
215  * It is a simple wrapper for xe_guard_disarm() with additional debug
216  * messages and xe_assert() to easily catch any illegal calls.
217  */
218 void xe_sriov_pf_disarm_guard(struct xe_device *xe, struct xe_guard *guard,
219 			      bool lockdown, void *who)
220 {
221 	bool disarmed;
222 
223 	xe_sriov_dbg_verbose(xe, "%s/%s by %ps\n",
224 			     guard->name, xe_guard_mode_str(lockdown),
225 			     who ?: __builtin_return_address(0));
226 
227 	disarmed = xe_guard_disarm(guard, lockdown);
228 	xe_assert_msg(xe, disarmed, "%s/%s not armed? last owner %ps",
229 		      guard->name, xe_guard_mode_str(lockdown), guard->owner);
230 }
231 
232 /**
233  * xe_sriov_pf_lockdown() - Lockdown the PF to prevent VFs enabling.
234  * @xe: the PF &xe_device
235  *
236  * This function can only be called on PF.
237  *
238  * Once the PF is locked down, it will not enable VFs.
239  * If VFs are already enabled, the -EBUSY will be returned.
240  * To allow the PF enable VFs again call xe_sriov_pf_end_lockdown().
241  *
242  * Return: 0 on success or a negative error code on failure.
243  */
244 int xe_sriov_pf_lockdown(struct xe_device *xe)
245 {
246 	xe_assert(xe, IS_SRIOV_PF(xe));
247 
248 	return xe_sriov_pf_arm_guard(xe, &xe->sriov.pf.guard_vfs_enabling, true,
249 				     __builtin_return_address(0));
250 }
251 
252 /**
253  * xe_sriov_pf_end_lockdown() - Allow the PF to enable VFs again.
254  * @xe: the PF &xe_device
255  *
256  * This function can only be called on PF.
257  * See xe_sriov_pf_lockdown() for details.
258  */
259 void xe_sriov_pf_end_lockdown(struct xe_device *xe)
260 {
261 	xe_assert(xe, IS_SRIOV_PF(xe));
262 
263 	xe_sriov_pf_disarm_guard(xe, &xe->sriov.pf.guard_vfs_enabling, true,
264 				 __builtin_return_address(0));
265 }
266 
267 /**
268  * xe_sriov_pf_print_vfs_summary - Print SR-IOV PF information.
269  * @xe: the &xe_device to print info from
270  * @p: the &drm_printer
271  *
272  * Print SR-IOV PF related information into provided DRM printer.
273  */
274 void xe_sriov_pf_print_vfs_summary(struct xe_device *xe, struct drm_printer *p)
275 {
276 	struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
277 
278 	xe_assert(xe, IS_SRIOV_PF(xe));
279 
280 	drm_printf(p, "total: %u\n", xe->sriov.pf.device_total_vfs);
281 	drm_printf(p, "supported: %u\n", xe->sriov.pf.driver_max_vfs);
282 	drm_printf(p, "enabled: %u\n", pci_num_vf(pdev));
283 }
284