Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752050AbdHATAA (ORCPT ); Tue, 1 Aug 2017 15:00:00 -0400 Received: from mail-qk0-f195.google.com ([209.85.220.195]:34783 "EHLO mail-qk0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751936AbdHAS76 (ORCPT ); Tue, 1 Aug 2017 14:59:58 -0400 Date: Tue, 1 Aug 2017 14:59:55 -0400 From: Jon Mason To: Logan Gunthorpe Cc: linux-ntb@googlegroups.com, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Dave Jiang , Allen Hubbe , Bjorn Helgaas , Greg Kroah-Hartman , Kurt Schwemmer , Stephen Bates , Serge Semin Subject: Re: [PATCH v3 13/16] switchtec_ntb: implement doorbell registers Message-ID: <20170801185954.GI4186@kudzu.us> References: <20170725205753.4735-1-logang@deltatee.com> <20170725205753.4735-14-logang@deltatee.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170725205753.4735-14-logang@deltatee.com> User-Agent: Mutt/1.8.3 (2017-05-23) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5496 Lines: 178 On Tue, Jul 25, 2017 at 02:57:50PM -0600, Logan Gunthorpe wrote: > Pretty straightforward implementation of doorbell registers. > The shift and mask were setup in an earlier patch and this just hooks > up the appropriate portion of the IDB register as the local doorbells > and the opposite portion of ODB as the peer doorbells. The DB mask is > protected by a spinlock to avoid concurrent read-modify-write accesses. > > Signed-off-by: Logan Gunthorpe > Reviewed-by: Stephen Bates > Reviewed-by: Kurt Schwemmer > --- > drivers/ntb/hw/mscc/switchtec_ntb.c | 89 +++++++++++++++++++++++++++++++++++-- > 1 file changed, 85 insertions(+), 4 deletions(-) > > diff --git a/drivers/ntb/hw/mscc/switchtec_ntb.c b/drivers/ntb/hw/mscc/switchtec_ntb.c > index 34d69fa8612d..3037ca730998 100644 > --- a/drivers/ntb/hw/mscc/switchtec_ntb.c > +++ b/drivers/ntb/hw/mscc/switchtec_ntb.c > @@ -98,6 +98,9 @@ struct switchtec_ntb { > int db_shift; > int db_peer_shift; > > + /* synchronize rmw access of db_mask and hw reg */ > + spinlock_t db_mask_lock; > + > int nr_direct_mw; > int nr_lut_mw; > int direct_mw_to_bar[MAX_DIRECT_MW]; > @@ -338,41 +341,115 @@ static int switchtec_ntb_link_disable(struct ntb_dev *ntb) > > static u64 switchtec_ntb_db_valid_mask(struct ntb_dev *ntb) > { > - return 0; > + struct switchtec_ntb *sndev = ntb_sndev(ntb); > + > + return sndev->db_valid_mask; > } > > static int switchtec_ntb_db_vector_count(struct ntb_dev *ntb) > { > - return 0; > + return 1; > } > > static u64 switchtec_ntb_db_vector_mask(struct ntb_dev *ntb, int db_vector) > { > - return 0; > + struct switchtec_ntb *sndev = ntb_sndev(ntb); > + > + if (db_vector < 0 || db_vector > 1) > + return 0; > + > + return sndev->db_valid_mask; > } > > static u64 switchtec_ntb_db_read(struct ntb_dev *ntb) > { > - return 0; > + u64 ret; > + struct switchtec_ntb *sndev = ntb_sndev(ntb); > + > + ret = ioread64(&sndev->mmio_self_dbmsg->idb) >> sndev->db_shift; > + > + return ret & sndev->db_valid_mask; > } > > static int switchtec_ntb_db_clear(struct ntb_dev *ntb, u64 db_bits) > { > + struct switchtec_ntb *sndev = ntb_sndev(ntb); > + > + iowrite64(db_bits << sndev->db_shift, &sndev->mmio_self_dbmsg->idb); > + > return 0; > } > > static int switchtec_ntb_db_set_mask(struct ntb_dev *ntb, u64 db_bits) > { > + unsigned long irqflags; > + struct switchtec_ntb *sndev = ntb_sndev(ntb); > + > + if (db_bits & ~sndev->db_valid_mask) > + return -EINVAL; > + > + spin_lock_irqsave(&sndev->db_mask_lock, irqflags); > + { > + sndev->db_mask |= db_bits << sndev->db_shift; > + iowrite64(~sndev->db_mask, &sndev->mmio_self_dbmsg->idb_mask); > + } unnecessary braces. Same for below > + spin_unlock_irqrestore(&sndev->db_mask_lock, irqflags); > + > return 0; > } > > static int switchtec_ntb_db_clear_mask(struct ntb_dev *ntb, u64 db_bits) > { > + unsigned long irqflags; > + struct switchtec_ntb *sndev = ntb_sndev(ntb); > + > + if (db_bits & ~sndev->db_valid_mask) > + return -EINVAL; > + > + spin_lock_irqsave(&sndev->db_mask_lock, irqflags); > + { > + sndev->db_mask &= ~(db_bits << sndev->db_shift); > + iowrite64(~sndev->db_mask, &sndev->mmio_self_dbmsg->idb_mask); > + } > + spin_unlock_irqrestore(&sndev->db_mask_lock, irqflags); > + > + return 0; > +} > + > +static u64 switchtec_ntb_db_read_mask(struct ntb_dev *ntb) > +{ > + struct switchtec_ntb *sndev = ntb_sndev(ntb); > + > + return (sndev->db_mask >> sndev->db_shift) & sndev->db_valid_mask; > +} > + > +static int switchtec_ntb_peer_db_addr(struct ntb_dev *ntb, > + phys_addr_t *db_addr, > + resource_size_t *db_size) > +{ > + struct switchtec_ntb *sndev = ntb_sndev(ntb); > + unsigned long offset; > + > + offset = (unsigned long)sndev->mmio_self_dbmsg->odb - > + (unsigned long)sndev->stdev->mmio; > + > + offset += sndev->db_shift / 8; > + > + if (db_addr) > + *db_addr = pci_resource_start(ntb->pdev, 0) + offset; > + if (db_size) > + *db_size = sizeof(u32); > + > return 0; > } > > static int switchtec_ntb_peer_db_set(struct ntb_dev *ntb, u64 db_bits) > { > + struct switchtec_ntb *sndev = ntb_sndev(ntb); > + > + iowrite64(db_bits << sndev->db_peer_shift, > + &sndev->mmio_self_dbmsg->odb); > + > return 0; > } > > @@ -413,6 +490,8 @@ static const struct ntb_dev_ops switchtec_ntb_ops = { > .db_clear = switchtec_ntb_db_clear, > .db_set_mask = switchtec_ntb_db_set_mask, > .db_clear_mask = switchtec_ntb_db_clear_mask, > + .db_read_mask = switchtec_ntb_db_read_mask, > + .peer_db_addr = switchtec_ntb_peer_db_addr, > .peer_db_set = switchtec_ntb_peer_db_set, > .spad_count = switchtec_ntb_spad_count, > .spad_read = switchtec_ntb_spad_read, > @@ -680,6 +759,8 @@ static irqreturn_t switchtec_ntb_doorbell_isr(int irq, void *dev) > > dev_dbg(&sndev->stdev->dev, "doorbell\n"); > > + ntb_db_event(&sndev->ntb, 0); > + > return IRQ_HANDLED; > } > > -- > 2.11.0 > > -- > You received this message because you are subscribed to the Google Groups "linux-ntb" group. > To unsubscribe from this group and stop receiving emails from it, send an email to linux-ntb+unsubscribe@googlegroups.com. > To post to this group, send email to linux-ntb@googlegroups.com. > To view this discussion on the web visit https://groups.google.com/d/msgid/linux-ntb/20170725205753.4735-14-logang%40deltatee.com. > For more options, visit https://groups.google.com/d/optout.