On Tue, Jul 12, 2016 at 12:36:35PM -0700, Adit Ranadive wrote: > This patch adds the UAR support for the paravirtual RDMA device. The UAR > pages are MMIO pages from the virtual PCI space. We define offsets within > this page to provide the fast data-path operations. > > Reviewed-by: Jorgen Hansen <jhansen@xxxxxxxxxx> > Reviewed-by: George Zhang <georgezhang@xxxxxxxxxx> > Reviewed-by: Aditya Sarwade <asarwade@xxxxxxxxxx> > Reviewed-by: Bryan Tan <bryantan@xxxxxxxxxx> > Signed-off-by: Adit Ranadive <aditr@xxxxxxxxxx> > --- > drivers/infiniband/hw/pvrdma/pvrdma_doorbell.c | 128 +++++++++++++++++++++++++ > 1 file changed, 128 insertions(+) > create mode 100644 drivers/infiniband/hw/pvrdma/pvrdma_doorbell.c > > diff --git a/drivers/infiniband/hw/pvrdma/pvrdma_doorbell.c b/drivers/infiniband/hw/pvrdma/pvrdma_doorbell.c > new file mode 100644 > index 0000000..d854f6d > --- /dev/null > +++ b/drivers/infiniband/hw/pvrdma/pvrdma_doorbell.c > @@ -0,0 +1,128 @@ > +/* > + * 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; > + > + /* Power of 2 */ > + if (num != 1 << (ffs(num) - 1)) > + 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) { > + set_bit(obj, tbl->table); > + obj |= tbl->top; > + } else { > + spin_unlock_irqrestore(&tbl->lock, flags); > + return -ENOMEM; > + } Please consider restructuring the above block to something like this: 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); > +} > -- > 2.7.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-rdma" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
