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// SPDX-License-Identifier: GPL-2.0
/* Copyright(c) 2019 Intel Corporation. All rights rsvd. */
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <uapi/linux/idxd.h>
#include "idxd.h"
#include "registers.h"
struct idxd_desc *idxd_alloc_desc(struct idxd_wq *wq, enum idxd_op_type optype)
{
struct idxd_desc *desc;
int idx;
struct idxd_device *idxd = wq->idxd;
if (idxd->state != IDXD_DEV_ENABLED)
return ERR_PTR(-EIO);
if (optype == IDXD_OP_BLOCK)
percpu_down_read(&wq->submit_lock);
else if (!percpu_down_read_trylock(&wq->submit_lock))
return ERR_PTR(-EBUSY);
if (!atomic_add_unless(&wq->dq_count, 1, wq->size)) {
int rc;
if (optype == IDXD_OP_NONBLOCK) {
percpu_up_read(&wq->submit_lock);
return ERR_PTR(-EAGAIN);
}
percpu_up_read(&wq->submit_lock);
percpu_down_write(&wq->submit_lock);
rc = wait_event_interruptible(wq->submit_waitq,
atomic_add_unless(&wq->dq_count,
1, wq->size) ||
idxd->state != IDXD_DEV_ENABLED);
percpu_up_write(&wq->submit_lock);
if (rc < 0)
return ERR_PTR(-EINTR);
if (idxd->state != IDXD_DEV_ENABLED)
return ERR_PTR(-EIO);
} else {
percpu_up_read(&wq->submit_lock);
}
idx = sbitmap_get(&wq->sbmap, 0, false);
if (idx < 0) {
atomic_dec(&wq->dq_count);
return ERR_PTR(-EAGAIN);
}
desc = wq->descs[idx];
memset(desc->hw, 0, sizeof(struct dsa_hw_desc));
memset(desc->completion, 0, sizeof(struct dsa_completion_record));
return desc;
}
void idxd_free_desc(struct idxd_wq *wq, struct idxd_desc *desc)
{
atomic_dec(&wq->dq_count);
sbitmap_clear_bit(&wq->sbmap, desc->id);
wake_up(&wq->submit_waitq);
}
int idxd_submit_desc(struct idxd_wq *wq, struct idxd_desc *desc)
{
struct idxd_device *idxd = wq->idxd;
int vec = desc->hw->int_handle;
void __iomem *portal;
if (idxd->state != IDXD_DEV_ENABLED)
return -EIO;
portal = wq->dportal + idxd_get_wq_portal_offset(IDXD_PORTAL_UNLIMITED);
/*
* The wmb() flushes writes to coherent DMA data before possibly
* triggering a DMA read. The wmb() is necessary even on UP because
* the recipient is a device.
*/
wmb();
iosubmit_cmds512(portal, desc->hw, 1);
/*
* Pending the descriptor to the lockless list for the irq_entry
* that we designated the descriptor to.
*/
if (desc->hw->flags & IDXD_OP_FLAG_RCI)
llist_add(&desc->llnode,
&idxd->irq_entries[vec].pending_llist);
return 0;
}
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