Commit 3df54c87 authored by Kelvin Cao's avatar Kelvin Cao Committed by Jon Mason
Browse files

ntb_hw_switchtec: Allow using Switchtec NTB in multi-partition setups 



Allow using Switchtec NTB in setups that have more than two partitions.
Note: this does not enable having multi-host communication, it only
allows for a single NTB link between two hosts in a network that might
have more than two.

Use following logic to determine the NT peer partition:

1) If there are 2 partitions, and the target vector is set in
   the Switchtec configuration, use the partition specified in target
   vector.
2) If there are 2 partitions and target vector is unset
   use the only other partition as specified in the NT EP map.
3) If there are more than 2 partitions and target vector is set
   use the other partition specified in target vector.
4) If there are more than 2 partitions and target vector is unset,
   this is invalid and report an error.

Signed-off-by: default avatarKelvin Cao <kelvin.cao@microsemi.com>
[logang@deltatee.com: commit message fleshed out]
Signed-off-by: default avatarLogan Gunthorpe <logang@deltatee.com>
Reviewed-by: default avatarLogan Gunthorpe <logang@deltatee.com>
Signed-off-by: default avatarJon Mason <jdmason@kudzu.us>
parent 2dd0f6a6

drivers/ntb/hw/mscc/ntb_hw_switchtec.c

+48 −9
Original line number Diff line number Diff line
@@ -777,9 +777,12 @@ static const struct ntb_dev_ops switchtec_ntb_ops = { 
	.peer_spad_addr		= switchtec_ntb_peer_spad_addr,

};



static void switchtec_ntb_init_sndev(struct switchtec_ntb *sndev)

static int switchtec_ntb_init_sndev(struct switchtec_ntb *sndev)

{

	u64 tpart_vec;

	int self;

	u64 part_map;

	int bit;



	sndev->ntb.pdev = sndev->stdev->pdev;

	sndev->ntb.topo = NTB_TOPO_SWITCH;
@@ -788,13 +791,47 @@ static void switchtec_ntb_init_sndev(struct switchtec_ntb *sndev) 
	sndev->self_partition = sndev->stdev->partition;



	sndev->mmio_ntb = sndev->stdev->mmio_ntb;



	self = sndev->self_partition;

	tpart_vec = ioread32(&sndev->mmio_ntb->ntp_info[self].target_part_high);

	tpart_vec <<= 32;

	tpart_vec |= ioread32(&sndev->mmio_ntb->ntp_info[self].target_part_low);



	part_map = ioread64(&sndev->mmio_ntb->ep_map);

	part_map &= ~(1 << sndev->self_partition);

	sndev->peer_partition = ffs(part_map) - 1;



	dev_dbg(&sndev->stdev->dev, "Partition ID %d of %d (%llx)\n",

		sndev->self_partition, sndev->stdev->partition_count,

		part_map);

	if (!ffs(tpart_vec)) {

		if (sndev->stdev->partition_count != 2) {

			dev_err(&sndev->stdev->dev,

				"ntb target partition not defined\n");

			return -ENODEV;

		}



		bit = ffs(part_map);

		if (!bit) {

			dev_err(&sndev->stdev->dev,

				"peer partition is not NT partition\n");

			return -ENODEV;

		}



		sndev->peer_partition = bit - 1;

	} else {

		if (ffs(tpart_vec) != fls(tpart_vec)) {

			dev_err(&sndev->stdev->dev,

				"ntb driver only supports 1 pair of 1-1 ntb mapping\n");

			return -ENODEV;

		}



		sndev->peer_partition = ffs(tpart_vec) - 1;

		if (!(part_map && (1 << sndev->peer_partition))) {

			dev_err(&sndev->stdev->dev,

				"ntb target partition is not NT partition\n");

			return -ENODEV;

		}

	}



	dev_dbg(&sndev->stdev->dev, "Partition ID %d of %d\n",

		sndev->self_partition, sndev->stdev->partition_count);



	sndev->mmio_ctrl = (void * __iomem)sndev->mmio_ntb +

		SWITCHTEC_NTB_REG_CTRL_OFFSET;
@@ -804,6 +841,8 @@ static void switchtec_ntb_init_sndev(struct switchtec_ntb *sndev) 
	sndev->mmio_self_ctrl = &sndev->mmio_ctrl[sndev->self_partition];

	sndev->mmio_peer_ctrl = &sndev->mmio_ctrl[sndev->peer_partition];

	sndev->mmio_self_dbmsg = &sndev->mmio_dbmsg[sndev->self_partition];



	return 0;

}



static int map_bars(int *map, struct ntb_ctrl_regs __iomem *ctrl)
@@ -1135,15 +1174,15 @@ static int switchtec_ntb_add(struct device *dev, 
	if (stdev->pdev->class != MICROSEMI_NTB_CLASSCODE)

		return -ENODEV;



	if (stdev->partition_count != 2)

		dev_warn(dev, "ntb driver only supports 2 partitions\n");



	sndev = kzalloc_node(sizeof(*sndev), GFP_KERNEL, dev_to_node(dev));

	if (!sndev)

		return -ENOMEM;



	sndev->stdev = stdev;

	switchtec_ntb_init_sndev(sndev);

	rc = switchtec_ntb_init_sndev(sndev);

	if (rc)

		goto free_and_exit;



	switchtec_ntb_init_mw(sndev);

	switchtec_ntb_init_db(sndev);

	switchtec_ntb_init_msgs(sndev);

include/linux/switchtec.h

+8 −0
Original line number Diff line number Diff line
@@ -168,6 +168,14 @@ struct ntb_info_regs { 
	u16 reserved1;

	u64 ep_map;

	u16 requester_id;

	u16 reserved2;

	u32 reserved3[4];

	struct nt_partition_info {

		u32 xlink_enabled;

		u32 target_part_low;

		u32 target_part_high;

		u32 reserved;

	} ntp_info[48];

} __packed;



struct part_cfg_regs {

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