1 // SPDX-License-Identifier: MIT 2 /* 3 * Copyright © 2023 Intel Corporation 4 */ 5 6 #include <drm/drm_managed.h> 7 8 #include "regs/xe_regs.h" 9 10 #include "xe_assert.h" 11 #include "xe_device.h" 12 #include "xe_mmio.h" 13 #include "xe_sriov.h" 14 #include "xe_sriov_pf.h" 15 16 /** 17 * xe_sriov_mode_to_string - Convert enum value to string. 18 * @mode: the &xe_sriov_mode to convert 19 * 20 * Returns: SR-IOV mode as a user friendly string. 21 */ 22 const char *xe_sriov_mode_to_string(enum xe_sriov_mode mode) 23 { 24 switch (mode) { 25 case XE_SRIOV_MODE_NONE: 26 return "none"; 27 case XE_SRIOV_MODE_PF: 28 return "SR-IOV PF"; 29 case XE_SRIOV_MODE_VF: 30 return "SR-IOV VF"; 31 default: 32 return "<invalid>"; 33 } 34 } 35 36 static bool test_is_vf(struct xe_device *xe) 37 { 38 u32 value = xe_mmio_read32(xe_root_mmio_gt(xe), VF_CAP_REG); 39 40 return value & VF_CAP; 41 } 42 43 /** 44 * xe_sriov_probe_early - Probe a SR-IOV mode. 45 * @xe: the &xe_device to probe mode on 46 * 47 * This function should be called only once and as soon as possible during 48 * driver probe to detect whether we are running a SR-IOV Physical Function 49 * (PF) or a Virtual Function (VF) device. 50 * 51 * SR-IOV PF mode detection is based on PCI @dev_is_pf() function. 52 * SR-IOV VF mode detection is based on dedicated MMIO register read. 53 */ 54 void xe_sriov_probe_early(struct xe_device *xe) 55 { 56 struct pci_dev *pdev = to_pci_dev(xe->drm.dev); 57 enum xe_sriov_mode mode = XE_SRIOV_MODE_NONE; 58 bool has_sriov = xe->info.has_sriov; 59 60 if (has_sriov) { 61 if (test_is_vf(xe)) 62 mode = XE_SRIOV_MODE_VF; 63 else if (xe_sriov_pf_readiness(xe)) 64 mode = XE_SRIOV_MODE_PF; 65 } else if (pci_sriov_get_totalvfs(pdev)) { 66 /* 67 * Even if we have not enabled SR-IOV support using the 68 * platform specific has_sriov flag, the hardware may still 69 * report SR-IOV capability and the PCI layer may wrongly 70 * advertise driver support to enable VFs. Explicitly reset 71 * the number of supported VFs to zero to avoid confusion. 72 */ 73 drm_info(&xe->drm, "Support for SR-IOV is not available\n"); 74 pci_sriov_set_totalvfs(pdev, 0); 75 } 76 77 xe_assert(xe, !xe->sriov.__mode); 78 xe->sriov.__mode = mode; 79 xe_assert(xe, xe->sriov.__mode); 80 81 if (has_sriov) 82 drm_info(&xe->drm, "Running in %s mode\n", 83 xe_sriov_mode_to_string(xe_device_sriov_mode(xe))); 84 } 85 86 static void fini_sriov(struct drm_device *drm, void *arg) 87 { 88 struct xe_device *xe = arg; 89 90 destroy_workqueue(xe->sriov.wq); 91 xe->sriov.wq = NULL; 92 } 93 94 /** 95 * xe_sriov_init - Initialize SR-IOV specific data. 96 * @xe: the &xe_device to initialize 97 * 98 * In this function we create dedicated workqueue that will be used 99 * by the SR-IOV specific workers. 100 * 101 * Return: 0 on success or a negative error code on failure. 102 */ 103 int xe_sriov_init(struct xe_device *xe) 104 { 105 if (!IS_SRIOV(xe)) 106 return 0; 107 108 if (IS_SRIOV_PF(xe)) { 109 int err = xe_sriov_pf_init_early(xe); 110 111 if (err) 112 return err; 113 } 114 115 xe_assert(xe, !xe->sriov.wq); 116 xe->sriov.wq = alloc_workqueue("xe-sriov-wq", 0, 0); 117 if (!xe->sriov.wq) 118 return -ENOMEM; 119 120 return drmm_add_action_or_reset(&xe->drm, fini_sriov, xe); 121 } 122 123 /** 124 * xe_sriov_print_info - Print basic SR-IOV information. 125 * @xe: the &xe_device to print info from 126 * @p: the &drm_printer 127 * 128 * Print SR-IOV related information into provided DRM printer. 129 */ 130 void xe_sriov_print_info(struct xe_device *xe, struct drm_printer *p) 131 { 132 drm_printf(p, "supported: %s\n", str_yes_no(xe_device_has_sriov(xe))); 133 drm_printf(p, "enabled: %s\n", str_yes_no(IS_SRIOV(xe))); 134 drm_printf(p, "mode: %s\n", xe_sriov_mode_to_string(xe_device_sriov_mode(xe))); 135 } 136 137 /** 138 * xe_sriov_function_name() - Get SR-IOV Function name. 139 * @n: the Function number (identifier) to get name of 140 * @buf: the buffer to format to 141 * @size: size of the buffer (shall be at least 5 bytes) 142 * 143 * Return: formatted function name ("PF" or "VF%u"). 144 */ 145 const char *xe_sriov_function_name(unsigned int n, char *buf, size_t size) 146 { 147 if (n) 148 snprintf(buf, size, "VF%u", n); 149 else 150 strscpy(buf, "PF", size); 151 return buf; 152 } 153