1 // SPDX-License-Identifier: GPL-2.0 2 /* Copyright(c) 2019 Intel Corporation. All rights rsvd. */ 3 #include <linux/init.h> 4 #include <linux/kernel.h> 5 #include <linux/module.h> 6 #include <linux/pci.h> 7 #include <uapi/linux/idxd.h> 8 #include "idxd.h" 9 #include "registers.h" 10 11 static struct idxd_desc *__get_desc(struct idxd_wq *wq, int idx, int cpu) 12 { 13 struct idxd_desc *desc; 14 struct idxd_device *idxd = wq->idxd; 15 16 desc = wq->descs[idx]; 17 memset(desc->hw, 0, sizeof(struct dsa_hw_desc)); 18 memset(desc->completion, 0, idxd->data->compl_size); 19 desc->cpu = cpu; 20 21 if (device_pasid_enabled(idxd)) 22 desc->hw->pasid = idxd->pasid; 23 24 return desc; 25 } 26 27 struct idxd_desc *idxd_alloc_desc(struct idxd_wq *wq, enum idxd_op_type optype) 28 { 29 int cpu, idx; 30 struct idxd_device *idxd = wq->idxd; 31 DEFINE_SBQ_WAIT(wait); 32 struct sbq_wait_state *ws; 33 struct sbitmap_queue *sbq; 34 35 if (idxd->state != IDXD_DEV_ENABLED) 36 return ERR_PTR(-EIO); 37 38 sbq = &wq->sbq; 39 idx = sbitmap_queue_get(sbq, &cpu); 40 if (idx < 0) { 41 if (optype == IDXD_OP_NONBLOCK) 42 return ERR_PTR(-EAGAIN); 43 } else { 44 return __get_desc(wq, idx, cpu); 45 } 46 47 ws = &sbq->ws[0]; 48 for (;;) { 49 sbitmap_prepare_to_wait(sbq, ws, &wait, TASK_INTERRUPTIBLE); 50 if (signal_pending_state(TASK_INTERRUPTIBLE, current)) 51 break; 52 idx = sbitmap_queue_get(sbq, &cpu); 53 if (idx >= 0) 54 break; 55 schedule(); 56 } 57 58 sbitmap_finish_wait(sbq, ws, &wait); 59 if (idx < 0) 60 return ERR_PTR(-EAGAIN); 61 62 return __get_desc(wq, idx, cpu); 63 } 64 65 void idxd_free_desc(struct idxd_wq *wq, struct idxd_desc *desc) 66 { 67 int cpu = desc->cpu; 68 69 desc->cpu = -1; 70 sbitmap_queue_clear(&wq->sbq, desc->id, cpu); 71 } 72 73 static struct idxd_desc *list_abort_desc(struct idxd_wq *wq, struct idxd_irq_entry *ie, 74 struct idxd_desc *desc) 75 { 76 struct idxd_desc *d, *n; 77 78 lockdep_assert_held(&ie->list_lock); 79 list_for_each_entry_safe(d, n, &ie->work_list, list) { 80 if (d == desc) { 81 list_del(&d->list); 82 return d; 83 } 84 } 85 86 /* 87 * At this point, the desc needs to be aborted is held by the completion 88 * handler where it has taken it off the pending list but has not added to the 89 * work list. It will be cleaned up by the interrupt handler when it sees the 90 * IDXD_COMP_DESC_ABORT for completion status. 91 */ 92 return NULL; 93 } 94 95 static void llist_abort_desc(struct idxd_wq *wq, struct idxd_irq_entry *ie, 96 struct idxd_desc *desc) 97 { 98 struct idxd_desc *d, *t, *found = NULL; 99 struct llist_node *head; 100 101 desc->completion->status = IDXD_COMP_DESC_ABORT; 102 /* 103 * Grab the list lock so it will block the irq thread handler. This allows the 104 * abort code to locate the descriptor need to be aborted. 105 */ 106 spin_lock(&ie->list_lock); 107 head = llist_del_all(&ie->pending_llist); 108 if (head) { 109 llist_for_each_entry_safe(d, t, head, llnode) { 110 if (d == desc) { 111 found = desc; 112 continue; 113 } 114 list_add_tail(&desc->list, &ie->work_list); 115 } 116 } 117 118 if (!found) 119 found = list_abort_desc(wq, ie, desc); 120 spin_unlock(&ie->list_lock); 121 122 if (found) 123 idxd_dma_complete_txd(found, IDXD_COMPLETE_ABORT, false); 124 } 125 126 int idxd_submit_desc(struct idxd_wq *wq, struct idxd_desc *desc) 127 { 128 struct idxd_device *idxd = wq->idxd; 129 struct idxd_irq_entry *ie = NULL; 130 u32 desc_flags = desc->hw->flags; 131 void __iomem *portal; 132 int rc; 133 134 if (idxd->state != IDXD_DEV_ENABLED) 135 return -EIO; 136 137 if (!percpu_ref_tryget_live(&wq->wq_active)) { 138 wait_for_completion(&wq->wq_resurrect); 139 if (!percpu_ref_tryget_live(&wq->wq_active)) 140 return -ENXIO; 141 } 142 143 portal = idxd_wq_portal_addr(wq); 144 145 /* 146 * The wmb() flushes writes to coherent DMA data before 147 * possibly triggering a DMA read. The wmb() is necessary 148 * even on UP because the recipient is a device. 149 */ 150 wmb(); 151 152 /* 153 * Pending the descriptor to the lockless list for the irq_entry 154 * that we designated the descriptor to. 155 */ 156 if (desc_flags & IDXD_OP_FLAG_RCI) { 157 ie = wq->ie; 158 if (ie->int_handle == INVALID_INT_HANDLE) 159 desc->hw->int_handle = ie->id; 160 else 161 desc->hw->int_handle = ie->int_handle; 162 163 llist_add(&desc->llnode, &ie->pending_llist); 164 } 165 166 if (wq_dedicated(wq)) { 167 iosubmit_cmds512(portal, desc->hw, 1); 168 } else { 169 /* 170 * It's not likely that we would receive queue full rejection 171 * since the descriptor allocation gates at wq size. If we 172 * receive a -EAGAIN, that means something went wrong such as the 173 * device is not accepting descriptor at all. 174 */ 175 rc = enqcmds(portal, desc->hw); 176 if (rc < 0) { 177 percpu_ref_put(&wq->wq_active); 178 /* abort operation frees the descriptor */ 179 if (ie) 180 llist_abort_desc(wq, ie, desc); 181 return rc; 182 } 183 } 184 185 percpu_ref_put(&wq->wq_active); 186 return 0; 187 } 188