// SPDX-License-Identifier: GPL-2.0
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/* Copyright(c) 2019 Intel Corporation. All rights rsvd. */
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#include <linux/init.h>
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#include <linux/kernel.h>
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#include <linux/module.h>
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#include <linux/pci.h>
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#include <uapi/linux/idxd.h>
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#include "idxd.h"
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#include "registers.h"
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static struct idxd_desc *__get_desc(struct idxd_wq *wq, int idx, int cpu)
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{
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struct idxd_desc *desc;
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desc = wq->descs[idx];
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memset(desc->hw, 0, sizeof(struct dsa_hw_desc));
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memset(desc->completion, 0, sizeof(struct dsa_completion_record));
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desc->cpu = cpu;
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return desc;
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}
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struct idxd_desc *idxd_alloc_desc(struct idxd_wq *wq, enum idxd_op_type optype)
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{
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int cpu, idx;
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struct idxd_device *idxd = wq->idxd;
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DEFINE_SBQ_WAIT(wait);
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struct sbq_wait_state *ws;
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struct sbitmap_queue *sbq;
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if (idxd->state != IDXD_DEV_ENABLED)
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return ERR_PTR(-EIO);
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sbq = &wq->sbq;
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idx = sbitmap_queue_get(sbq, &cpu);
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if (idx < 0) {
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if (optype == IDXD_OP_NONBLOCK)
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return ERR_PTR(-EAGAIN);
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} else {
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return __get_desc(wq, idx, cpu);
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}
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ws = &sbq->ws[0];
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for (;;) {
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sbitmap_prepare_to_wait(sbq, ws, &wait, TASK_INTERRUPTIBLE);
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if (signal_pending_state(TASK_INTERRUPTIBLE, current))
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break;
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idx = sbitmap_queue_get(sbq, &cpu);
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if (idx >= 0)
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break;
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schedule();
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}
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sbitmap_finish_wait(sbq, ws, &wait);
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if (idx < 0)
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return ERR_PTR(-EAGAIN);
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return __get_desc(wq, idx, cpu);
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}
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void idxd_free_desc(struct idxd_wq *wq, struct idxd_desc *desc)
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{
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int cpu = desc->cpu;
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desc->cpu = -1;
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sbitmap_queue_clear(&wq->sbq, desc->id, cpu);
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}
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int idxd_submit_desc(struct idxd_wq *wq, struct idxd_desc *desc)
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{
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struct idxd_device *idxd = wq->idxd;
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int vec = desc->hw->int_handle;
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void __iomem *portal;
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if (idxd->state != IDXD_DEV_ENABLED)
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return -EIO;
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portal = wq->dportal;
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/*
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* The wmb() flushes writes to coherent DMA data before possibly
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* triggering a DMA read. The wmb() is necessary even on UP because
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* the recipient is a device.
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*/
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wmb();
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iosubmit_cmds512(portal, desc->hw, 1);
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/*
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* Pending the descriptor to the lockless list for the irq_entry
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* that we designated the descriptor to.
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*/
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if (desc->hw->flags & IDXD_OP_FLAG_RCI)
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llist_add(&desc->llnode,
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&idxd->irq_entries[vec].pending_llist);
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return 0;
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}
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