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>
7 #include <uapi/linux/idxd.h>
11 static struct idxd_desc *__get_desc(struct idxd_wq *wq, int idx, int cpu)
13 struct idxd_desc *desc;
14 struct idxd_device *idxd = wq->idxd;
16 desc = wq->descs[idx];
17 memset(desc->hw, 0, sizeof(struct dsa_hw_desc));
18 memset(desc->completion, 0, idxd->compl_size);
21 if (device_pasid_enabled(idxd))
22 desc->hw->pasid = idxd->pasid;
25 * Descriptor completion vectors are 1-8 for MSIX. We will round
26 * robin through the 8 vectors.
28 wq->vec_ptr = (wq->vec_ptr % idxd->num_wq_irqs) + 1;
29 desc->hw->int_handle = wq->vec_ptr;
33 struct idxd_desc *idxd_alloc_desc(struct idxd_wq *wq, enum idxd_op_type optype)
36 struct idxd_device *idxd = wq->idxd;
37 DEFINE_SBQ_WAIT(wait);
38 struct sbq_wait_state *ws;
39 struct sbitmap_queue *sbq;
41 if (idxd->state != IDXD_DEV_ENABLED)
45 idx = sbitmap_queue_get(sbq, &cpu);
47 if (optype == IDXD_OP_NONBLOCK)
48 return ERR_PTR(-EAGAIN);
50 return __get_desc(wq, idx, cpu);
55 sbitmap_prepare_to_wait(sbq, ws, &wait, TASK_INTERRUPTIBLE);
56 if (signal_pending_state(TASK_INTERRUPTIBLE, current))
58 idx = sbitmap_queue_get(sbq, &cpu);
64 sbitmap_finish_wait(sbq, ws, &wait);
66 return ERR_PTR(-EAGAIN);
68 return __get_desc(wq, idx, cpu);
71 void idxd_free_desc(struct idxd_wq *wq, struct idxd_desc *desc)
76 sbitmap_queue_clear(&wq->sbq, desc->id, cpu);
79 int idxd_submit_desc(struct idxd_wq *wq, struct idxd_desc *desc)
81 struct idxd_device *idxd = wq->idxd;
82 int vec = desc->hw->int_handle;
86 if (idxd->state != IDXD_DEV_ENABLED)
92 * The wmb() flushes writes to coherent DMA data before
93 * possibly triggering a DMA read. The wmb() is necessary
94 * even on UP because the recipient is a device.
97 if (wq_dedicated(wq)) {
98 iosubmit_cmds512(portal, desc->hw, 1);
101 * It's not likely that we would receive queue full rejection
102 * since the descriptor allocation gates at wq size. If we
103 * receive a -EAGAIN, that means something went wrong such as the
104 * device is not accepting descriptor at all.
106 rc = enqcmds(portal, desc->hw);
112 * Pending the descriptor to the lockless list for the irq_entry
113 * that we designated the descriptor to.
115 if (desc->hw->flags & IDXD_OP_FLAG_RCI)
116 llist_add(&desc->llnode,
117 &idxd->irq_entries[vec].pending_llist);