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 15 desc = wq->descs[idx]; 16 memset(desc->hw, 0, sizeof(struct dsa_hw_desc)); 17 memset(desc->completion, 0, sizeof(struct dsa_completion_record)); 18 desc->cpu = cpu; 19 return desc; 20 } 21 22 struct idxd_desc *idxd_alloc_desc(struct idxd_wq *wq, enum idxd_op_type optype) 23 { 24 int cpu, idx; 25 struct idxd_device *idxd = wq->idxd; 26 DEFINE_SBQ_WAIT(wait); 27 struct sbq_wait_state *ws; 28 struct sbitmap_queue *sbq; 29 30 if (idxd->state != IDXD_DEV_ENABLED) 31 return ERR_PTR(-EIO); 32 33 sbq = &wq->sbq; 34 idx = sbitmap_queue_get(sbq, &cpu); 35 if (idx < 0) { 36 if (optype == IDXD_OP_NONBLOCK) 37 return ERR_PTR(-EAGAIN); 38 } else { 39 return __get_desc(wq, idx, cpu); 40 } 41 42 ws = &sbq->ws[0]; 43 for (;;) { 44 sbitmap_prepare_to_wait(sbq, ws, &wait, TASK_INTERRUPTIBLE); 45 if (signal_pending_state(TASK_INTERRUPTIBLE, current)) 46 break; 47 idx = sbitmap_queue_get(sbq, &cpu); 48 if (idx > 0) 49 break; 50 schedule(); 51 } 52 53 sbitmap_finish_wait(sbq, ws, &wait); 54 if (idx < 0) 55 return ERR_PTR(-EAGAIN); 56 57 return __get_desc(wq, idx, cpu); 58 } 59 60 void idxd_free_desc(struct idxd_wq *wq, struct idxd_desc *desc) 61 { 62 int cpu = desc->cpu; 63 64 desc->cpu = -1; 65 sbitmap_queue_clear(&wq->sbq, desc->id, cpu); 66 } 67 68 int idxd_submit_desc(struct idxd_wq *wq, struct idxd_desc *desc) 69 { 70 struct idxd_device *idxd = wq->idxd; 71 int vec = desc->hw->int_handle; 72 void __iomem *portal; 73 74 if (idxd->state != IDXD_DEV_ENABLED) 75 return -EIO; 76 77 portal = wq->dportal + idxd_get_wq_portal_offset(IDXD_PORTAL_UNLIMITED); 78 /* 79 * The wmb() flushes writes to coherent DMA data before possibly 80 * triggering a DMA read. The wmb() is necessary even on UP because 81 * the recipient is a device. 82 */ 83 wmb(); 84 iosubmit_cmds512(portal, desc->hw, 1); 85 86 /* 87 * Pending the descriptor to the lockless list for the irq_entry 88 * that we designated the descriptor to. 89 */ 90 if (desc->hw->flags & IDXD_OP_FLAG_RCI) 91 llist_add(&desc->llnode, 92 &idxd->irq_entries[vec].pending_llist); 93 94 return 0; 95 } 96