1 // SPDX-License-Identifier: MIT
2 /*
3 * Copyright © 2023-2024 Intel Corporation
4 */
5
6 #include "xe_assert.h"
7 #include "xe_device.h"
8 #include "xe_gt_sriov_pf_config.h"
9 #include "xe_gt_sriov_pf_control.h"
10 #include "xe_pci_sriov.h"
11 #include "xe_pm.h"
12 #include "xe_sriov.h"
13 #include "xe_sriov_pf_helpers.h"
14 #include "xe_sriov_printk.h"
15
pf_needs_provisioning(struct xe_gt * gt,unsigned int num_vfs)16 static int pf_needs_provisioning(struct xe_gt *gt, unsigned int num_vfs)
17 {
18 unsigned int n;
19
20 for (n = 1; n <= num_vfs; n++)
21 if (!xe_gt_sriov_pf_config_is_empty(gt, n))
22 return false;
23
24 return true;
25 }
26
pf_provision_vfs(struct xe_device * xe,unsigned int num_vfs)27 static int pf_provision_vfs(struct xe_device *xe, unsigned int num_vfs)
28 {
29 struct xe_gt *gt;
30 unsigned int id;
31 int result = 0, err;
32
33 for_each_gt(gt, xe, id) {
34 if (!pf_needs_provisioning(gt, num_vfs))
35 continue;
36 err = xe_gt_sriov_pf_config_set_fair(gt, VFID(1), num_vfs);
37 result = result ?: err;
38 }
39
40 return result;
41 }
42
pf_unprovision_vfs(struct xe_device * xe,unsigned int num_vfs)43 static void pf_unprovision_vfs(struct xe_device *xe, unsigned int num_vfs)
44 {
45 struct xe_gt *gt;
46 unsigned int id;
47 unsigned int n;
48
49 for_each_gt(gt, xe, id)
50 for (n = 1; n <= num_vfs; n++)
51 xe_gt_sriov_pf_config_release(gt, n, true);
52 }
53
pf_reset_vfs(struct xe_device * xe,unsigned int num_vfs)54 static void pf_reset_vfs(struct xe_device *xe, unsigned int num_vfs)
55 {
56 struct xe_gt *gt;
57 unsigned int id;
58 unsigned int n;
59
60 for_each_gt(gt, xe, id)
61 for (n = 1; n <= num_vfs; n++)
62 xe_gt_sriov_pf_control_trigger_flr(gt, n);
63 }
64
xe_pci_pf_get_vf_dev(struct xe_device * xe,unsigned int vf_id)65 static struct pci_dev *xe_pci_pf_get_vf_dev(struct xe_device *xe, unsigned int vf_id)
66 {
67 struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
68
69 xe_assert(xe, IS_SRIOV_PF(xe));
70
71 /* caller must use pci_dev_put() */
72 return pci_get_domain_bus_and_slot(pci_domain_nr(pdev->bus),
73 pdev->bus->number,
74 pci_iov_virtfn_devfn(pdev, vf_id));
75 }
76
pf_link_vfs(struct xe_device * xe,int num_vfs)77 static void pf_link_vfs(struct xe_device *xe, int num_vfs)
78 {
79 struct pci_dev *pdev_pf = to_pci_dev(xe->drm.dev);
80 struct device_link *link;
81 struct pci_dev *pdev_vf;
82 unsigned int n;
83
84 /*
85 * When both PF and VF devices are enabled on the host, during system
86 * resume they are resuming in parallel.
87 *
88 * But PF has to complete the provision of VF first to allow any VFs to
89 * successfully resume.
90 *
91 * Create a parent-child device link between PF and VF devices that will
92 * enforce correct resume order.
93 */
94 for (n = 1; n <= num_vfs; n++) {
95 pdev_vf = xe_pci_pf_get_vf_dev(xe, n - 1);
96
97 /* unlikely, something weird is happening, abort */
98 if (!pdev_vf) {
99 xe_sriov_err(xe, "Cannot find VF%u device, aborting link%s creation!\n",
100 n, str_plural(num_vfs));
101 break;
102 }
103
104 link = device_link_add(&pdev_vf->dev, &pdev_pf->dev,
105 DL_FLAG_AUTOREMOVE_CONSUMER);
106 /* unlikely and harmless, continue with other VFs */
107 if (!link)
108 xe_sriov_notice(xe, "Failed linking VF%u\n", n);
109
110 pci_dev_put(pdev_vf);
111 }
112 }
113
pf_enable_vfs(struct xe_device * xe,int num_vfs)114 static int pf_enable_vfs(struct xe_device *xe, int num_vfs)
115 {
116 struct pci_dev *pdev = to_pci_dev(xe->drm.dev);
117 int total_vfs = xe_sriov_pf_get_totalvfs(xe);
118 int err;
119
120 xe_assert(xe, IS_SRIOV_PF(xe));
121 xe_assert(xe, num_vfs > 0);
122 xe_assert(xe, num_vfs <= total_vfs);
123 xe_sriov_dbg(xe, "enabling %u VF%s\n", num_vfs, str_plural(num_vfs));
124
125 /*
126 * We must hold additional reference to the runtime PM to keep PF in D0
127 * during VFs lifetime, as our VFs do not implement the PM capability.
128 *
129 * With PF being in D0 state, all VFs will also behave as in D0 state.
130 * This will also keep GuC alive with all VFs' configurations.
131 *
132 * We will release this additional PM reference in pf_disable_vfs().
133 */
134 xe_pm_runtime_get_noresume(xe);
135
136 err = pf_provision_vfs(xe, num_vfs);
137 if (err < 0)
138 goto failed;
139
140 err = pci_enable_sriov(pdev, num_vfs);
141 if (err < 0)
142 goto failed;
143
144 pf_link_vfs(xe, num_vfs);
145
146 xe_sriov_info(xe, "Enabled %u of %u VF%s\n",
147 num_vfs, total_vfs, str_plural(total_vfs));
148 return num_vfs;
149
150 failed:
151 pf_unprovision_vfs(xe, num_vfs);
152 xe_pm_runtime_put(xe);
153
154 xe_sriov_notice(xe, "Failed to enable %u VF%s (%pe)\n",
155 num_vfs, str_plural(num_vfs), ERR_PTR(err));
156 return err;
157 }
158
pf_disable_vfs(struct xe_device * xe)159 static int pf_disable_vfs(struct xe_device *xe)
160 {
161 struct device *dev = xe->drm.dev;
162 struct pci_dev *pdev = to_pci_dev(dev);
163 u16 num_vfs = pci_num_vf(pdev);
164
165 xe_assert(xe, IS_SRIOV_PF(xe));
166 xe_sriov_dbg(xe, "disabling %u VF%s\n", num_vfs, str_plural(num_vfs));
167
168 if (!num_vfs)
169 return 0;
170
171 pci_disable_sriov(pdev);
172
173 pf_reset_vfs(xe, num_vfs);
174
175 pf_unprovision_vfs(xe, num_vfs);
176
177 /* not needed anymore - see pf_enable_vfs() */
178 xe_pm_runtime_put(xe);
179
180 xe_sriov_info(xe, "Disabled %u VF%s\n", num_vfs, str_plural(num_vfs));
181 return 0;
182 }
183
184 /**
185 * xe_pci_sriov_configure - Configure SR-IOV (enable/disable VFs).
186 * @pdev: the &pci_dev
187 * @num_vfs: number of VFs to enable or zero to disable all VFs
188 *
189 * This is the Xe implementation of struct pci_driver.sriov_configure callback.
190 *
191 * This callback will be called by the PCI subsystem to enable or disable SR-IOV
192 * Virtual Functions (VFs) as requested by the used via the PCI sysfs interface.
193 *
194 * Return: number of configured VFs or a negative error code on failure.
195 */
xe_pci_sriov_configure(struct pci_dev * pdev,int num_vfs)196 int xe_pci_sriov_configure(struct pci_dev *pdev, int num_vfs)
197 {
198 struct xe_device *xe = pdev_to_xe_device(pdev);
199 int ret;
200
201 if (!IS_SRIOV_PF(xe))
202 return -ENODEV;
203
204 if (num_vfs < 0)
205 return -EINVAL;
206
207 if (num_vfs > xe_sriov_pf_get_totalvfs(xe))
208 return -ERANGE;
209
210 if (num_vfs && pci_num_vf(pdev))
211 return -EBUSY;
212
213 xe_pm_runtime_get(xe);
214 if (num_vfs > 0)
215 ret = pf_enable_vfs(xe, num_vfs);
216 else
217 ret = pf_disable_vfs(xe);
218 xe_pm_runtime_put(xe);
219
220 return ret;
221 }
222