linux/drivers/infiniband/hw/vmw_pvrdma/pvrdma_doorbell.c

128 lines
3.9 KiB
C

/*
* Copyright (c) 2012-2016 VMware, Inc. All rights reserved.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of EITHER the GNU General Public License
* version 2 as published by the Free Software Foundation or the BSD
* 2-Clause License. This program is distributed in the hope that it
* will be useful, but WITHOUT ANY WARRANTY; WITHOUT EVEN THE IMPLIED
* WARRANTY OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU General Public License version 2 for more details at
* http://www.gnu.org/licenses/old-licenses/gpl-2.0.en.html.
*
* You should have received a copy of the GNU General Public License
* along with this program available in the file COPYING in the main
* directory of this source tree.
*
* The BSD 2-Clause License
*
* Redistribution and use in source and binary forms, with or
* without modification, are permitted provided that the following
* conditions are met:
*
* - Redistributions of source code must retain the above
* copyright notice, this list of conditions and the following
* disclaimer.
*
* - Redistributions in binary form must reproduce the above
* copyright notice, this list of conditions and the following
* disclaimer in the documentation and/or other materials
* provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
* LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
* COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT,
* INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
* STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
* OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include <linux/bitmap.h>
#include <linux/errno.h>
#include <linux/slab.h>
#include "pvrdma.h"
int pvrdma_uar_table_init(struct pvrdma_dev *dev)
{
u32 num = dev->dsr->caps.max_uar;
u32 mask = num - 1;
struct pvrdma_id_table *tbl = &dev->uar_table.tbl;
if (!is_power_of_2(num))
return -EINVAL;
tbl->last = 0;
tbl->top = 0;
tbl->max = num;
tbl->mask = mask;
spin_lock_init(&tbl->lock);
tbl->table = kcalloc(BITS_TO_LONGS(num), sizeof(long), GFP_KERNEL);
if (!tbl->table)
return -ENOMEM;
/* 0th UAR is taken by the device. */
set_bit(0, tbl->table);
return 0;
}
void pvrdma_uar_table_cleanup(struct pvrdma_dev *dev)
{
struct pvrdma_id_table *tbl = &dev->uar_table.tbl;
kfree(tbl->table);
}
int pvrdma_uar_alloc(struct pvrdma_dev *dev, struct pvrdma_uar_map *uar)
{
struct pvrdma_id_table *tbl;
unsigned long flags;
u32 obj;
tbl = &dev->uar_table.tbl;
spin_lock_irqsave(&tbl->lock, flags);
obj = find_next_zero_bit(tbl->table, tbl->max, tbl->last);
if (obj >= tbl->max) {
tbl->top = (tbl->top + tbl->max) & tbl->mask;
obj = find_first_zero_bit(tbl->table, tbl->max);
}
if (obj >= tbl->max) {
spin_unlock_irqrestore(&tbl->lock, flags);
return -ENOMEM;
}
set_bit(obj, tbl->table);
obj |= tbl->top;
spin_unlock_irqrestore(&tbl->lock, flags);
uar->index = obj;
uar->pfn = (pci_resource_start(dev->pdev, PVRDMA_PCI_RESOURCE_UAR) >>
PAGE_SHIFT) + uar->index;
return 0;
}
void pvrdma_uar_free(struct pvrdma_dev *dev, struct pvrdma_uar_map *uar)
{
struct pvrdma_id_table *tbl = &dev->uar_table.tbl;
unsigned long flags;
u32 obj;
obj = uar->index & (tbl->max - 1);
spin_lock_irqsave(&tbl->lock, flags);
clear_bit(obj, tbl->table);
tbl->last = min(tbl->last, obj);
tbl->top = (tbl->top + tbl->max) & tbl->mask;
spin_unlock_irqrestore(&tbl->lock, flags);
}