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[PATCH v2 13/16] switchtec_ntb: implement doorbell registers

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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 <logang@deltatee.com>
Reviewed-by: Stephen Bates <sbates@raithlin.com>
Reviewed-by: Kurt Schwemmer <kurt.schwemmer@microsemi.com>
---
 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 dba14188ba95..0bd9c8cae688 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);
+	}
+	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

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Thread

[PATCH v2 00/16] Switchtec NTB Support Logan Gunthorpe <logang@deltatee.com> - 2017-07-18 18:10 +0200
  [PATCH v2 12/16] switchtec_ntb: add link management Logan Gunthorpe <logang@deltatee.com> - 2017-07-18 18:10 +0200
  [PATCH v2 04/16] switchtec: add link event notifier callback Logan Gunthorpe <logang@deltatee.com> - 2017-07-18 18:10 +0200
  [PATCH v2 11/16] switchtec_ntb: add skeleton NTB driver Logan Gunthorpe <logang@deltatee.com> - 2017-07-18 18:10 +0200
  [PATCH v2 15/16] switchtec_ntb: add memory window support Logan Gunthorpe <logang@deltatee.com> - 2017-07-18 18:10 +0200
  [PATCH v2 13/16] switchtec_ntb: implement doorbell registers Logan Gunthorpe <logang@deltatee.com> - 2017-07-18 18:10 +0200
  [PATCH v2 07/16] ntb: ntb_test: ensure the link is up before trying to configure the mws Logan Gunthorpe <logang@deltatee.com> - 2017-07-18 18:10 +0200
  [PATCH v2 02/16] switchtec: export class symbol for use in upper layer driver Logan Gunthorpe <logang@deltatee.com> - 2017-07-18 18:10 +0200
  [PATCH v2 03/16] switchtec: add NTB hardware register definitions Logan Gunthorpe <logang@deltatee.com> - 2017-07-18 18:10 +0200
  [PATCH v2 16/16] switchtec_ntb: update switchtec documentation with notes for NTB Logan Gunthorpe <logang@deltatee.com> - 2017-07-18 18:10 +0200
  [PATCH v2 01/16] switchtec: move structure definitions into a common header Logan Gunthorpe <logang@deltatee.com> - 2017-07-18 18:10 +0200
  RE: [PATCH v2 00/16] Switchtec NTB Support "Allen Hubbe" <Allen.Hubbe@dell.com> - 2017-07-18 20:00 +0200
    Re: [PATCH v2 00/16] Switchtec NTB Support Logan Gunthorpe <logang@deltatee.com> - 2017-07-18 20:10 +0200

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