bnxt_en: Add interface to support RDMA driver.

Since the network driver and RDMA driver operate on the same PCI function,
we need to create an interface to allow the RDMA driver to share resources
with the network driver.

1. Create a new bnxt_en_dev struct which will be returned by
bnxt_ulp_probe() upon success.  After that, all calls from the RDMA driver
to bnxt_en will pass a pointer to this struct.

2. This struct contains additional function pointers to register, request
msix, send fw messages, register for async events.

3. If the RDMA driver wants to enable RDMA on the function, it needs to
call the function pointer bnxt_register_device().  A ulp_ops structure
is passed for RCU protected upcalls from bnxt_en to the RDMA driver.

4. The RDMA driver can call firmware APIs using the bnxt_send_fw_msg()
function pointer.

5. 1 stats context is reserved when the RDMA driver registers.  MSIX
and completion rings are reserved when the RDMA driver calls
bnxt_request_msix() function pointer.

6. When the RDMA driver calls bnxt_unregister_device(), all RDMA resources
will be cleaned up.

v2: Fixed 2 uninitialized variable warnings.

Signed-off-by: Somnath Kotur <somnath.kotur@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 346 insertions, 0 deletions

diff --git a/drivers/net/ethernet/broadcom/bnxt/bnxt_ulp.c b/drivers/net/ethernet/broadcom/bnxt/bnxt_ulp.c
new file mode 100644
index 000000000000..8b7464b76501
--- /dev/null
+++ b/drivers/net/ethernet/broadcom/bnxt/bnxt_ulp.c
@@ -0,0 +1,346 @@
+/* Broadcom NetXtreme-C/E network driver.
+ *
+ * Copyright (c) 2016 Broadcom Limited
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation.
+ */
+
+#include <linux/module.h>
+
+#include <linux/kernel.h>
+#include <linux/errno.h>
+#include <linux/interrupt.h>
+#include <linux/pci.h>
+#include <linux/netdevice.h>
+#include <linux/rtnetlink.h>
+#include <linux/bitops.h>
+#include <linux/irq.h>
+#include <asm/byteorder.h>
+#include <linux/bitmap.h>
+
+#include "bnxt_hsi.h"
+#include "bnxt.h"
+#include "bnxt_ulp.h"
+
+static int bnxt_register_dev(struct bnxt_en_dev *edev, int ulp_id,
+			     struct bnxt_ulp_ops *ulp_ops, void *handle)
+{
+	struct net_device *dev = edev->net;
+	struct bnxt *bp = netdev_priv(dev);
+	struct bnxt_ulp *ulp;
+
+	ASSERT_RTNL();
+	if (ulp_id >= BNXT_MAX_ULP)
+		return -EINVAL;
+
+	ulp = &edev->ulp_tbl[ulp_id];
+	if (rcu_access_pointer(ulp->ulp_ops)) {
+		netdev_err(bp->dev, "ulp id %d already registered\n", ulp_id);
+		return -EBUSY;
+	}
+	if (ulp_id == BNXT_ROCE_ULP) {
+		unsigned int max_stat_ctxs;
+
+		max_stat_ctxs = bnxt_get_max_func_stat_ctxs(bp);
+		if (max_stat_ctxs <= BNXT_MIN_ROCE_STAT_CTXS ||
+		    bp->num_stat_ctxs == max_stat_ctxs)
+			return -ENOMEM;
+		bnxt_set_max_func_stat_ctxs(bp, max_stat_ctxs -
+					    BNXT_MIN_ROCE_STAT_CTXS);
+	}
+
+	atomic_set(&ulp->ref_count, 0);
+	ulp->handle = handle;
+	rcu_assign_pointer(ulp->ulp_ops, ulp_ops);
+
+	if (ulp_id == BNXT_ROCE_ULP) {
+		if (test_bit(BNXT_STATE_OPEN, &bp->state))
+			bnxt_hwrm_vnic_cfg(bp, 0);
+	}
+
+	return 0;
+}
+
+static int bnxt_unregister_dev(struct bnxt_en_dev *edev, int ulp_id)
+{
+	struct net_device *dev = edev->net;
+	struct bnxt *bp = netdev_priv(dev);
+	struct bnxt_ulp *ulp;
+	int i = 0;
+
+	ASSERT_RTNL();
+	if (ulp_id >= BNXT_MAX_ULP)
+		return -EINVAL;
+
+	ulp = &edev->ulp_tbl[ulp_id];
+	if (!rcu_access_pointer(ulp->ulp_ops)) {
+		netdev_err(bp->dev, "ulp id %d not registered\n", ulp_id);
+		return -EINVAL;
+	}
+	if (ulp_id == BNXT_ROCE_ULP) {
+		unsigned int max_stat_ctxs;
+
+		max_stat_ctxs = bnxt_get_max_func_stat_ctxs(bp);
+		bnxt_set_max_func_stat_ctxs(bp, max_stat_ctxs + 1);
+	}
+	if (ulp->max_async_event_id)
+		bnxt_hwrm_func_rgtr_async_events(bp, NULL, 0);
+
+	RCU_INIT_POINTER(ulp->ulp_ops, NULL);
+	synchronize_rcu();
+	ulp->max_async_event_id = 0;
+	ulp->async_events_bmap = NULL;
+	while (atomic_read(&ulp->ref_count) != 0 && i < 10) {
+		msleep(100);
+		i++;
+	}
+	return 0;
+}
+
+static int bnxt_req_msix_vecs(struct bnxt_en_dev *edev, int ulp_id,
+			      struct bnxt_msix_entry *ent, int num_msix)
+{
+	struct net_device *dev = edev->net;
+	struct bnxt *bp = netdev_priv(dev);
+	int max_idx, max_cp_rings;
+	int avail_msix, i, idx;
+
+	ASSERT_RTNL();
+	if (ulp_id != BNXT_ROCE_ULP)
+		return -EINVAL;
+
+	if (!(bp->flags & BNXT_FLAG_USING_MSIX))
+		return -ENODEV;
+
+	max_cp_rings = bnxt_get_max_func_cp_rings(bp);
+	max_idx = min_t(int, bp->total_irqs, max_cp_rings);
+	avail_msix = max_idx - bp->cp_nr_rings;
+	if (!avail_msix)
+		return -ENOMEM;
+	if (avail_msix > num_msix)
+		avail_msix = num_msix;
+
+	idx = max_idx - avail_msix;
+	for (i = 0; i < avail_msix; i++) {
+		ent[i].vector = bp->irq_tbl[idx + i].vector;
+		ent[i].ring_idx = idx + i;
+		ent[i].db_offset = (idx + i) * 0x80;
+	}
+	bnxt_set_max_func_irqs(bp, max_idx - avail_msix);
+	bnxt_set_max_func_cp_rings(bp, max_cp_rings - avail_msix);
+	edev->ulp_tbl[ulp_id].msix_requested = avail_msix;
+	return avail_msix;
+}
+
+static int bnxt_free_msix_vecs(struct bnxt_en_dev *edev, int ulp_id)
+{
+	struct net_device *dev = edev->net;
+	struct bnxt *bp = netdev_priv(dev);
+	int max_cp_rings, msix_requested;
+
+	ASSERT_RTNL();
+	if (ulp_id != BNXT_ROCE_ULP)
+		return -EINVAL;
+
+	max_cp_rings = bnxt_get_max_func_cp_rings(bp);
+	msix_requested = edev->ulp_tbl[ulp_id].msix_requested;
+	bnxt_set_max_func_cp_rings(bp, max_cp_rings + msix_requested);
+	edev->ulp_tbl[ulp_id].msix_requested = 0;
+	bnxt_set_max_func_irqs(bp, bp->total_irqs);
+	return 0;
+}
+
+void bnxt_subtract_ulp_resources(struct bnxt *bp, int ulp_id)
+{
+	ASSERT_RTNL();
+	if (bnxt_ulp_registered(bp->edev, ulp_id)) {
+		struct bnxt_en_dev *edev = bp->edev;
+		unsigned int msix_req, max;
+
+		msix_req = edev->ulp_tbl[ulp_id].msix_requested;
+		max = bnxt_get_max_func_cp_rings(bp);
+		bnxt_set_max_func_cp_rings(bp, max - msix_req);
+		max = bnxt_get_max_func_stat_ctxs(bp);
+		bnxt_set_max_func_stat_ctxs(bp, max - 1);
+	}
+}
+
+static int bnxt_send_msg(struct bnxt_en_dev *edev, int ulp_id,
+			 struct bnxt_fw_msg *fw_msg)
+{
+	struct net_device *dev = edev->net;
+	struct bnxt *bp = netdev_priv(dev);
+	struct input *req;
+	int rc;
+
+	mutex_lock(&bp->hwrm_cmd_lock);
+	req = fw_msg->msg;
+	req->resp_addr = cpu_to_le64(bp->hwrm_cmd_resp_dma_addr);
+	rc = _hwrm_send_message(bp, fw_msg->msg, fw_msg->msg_len,
+				fw_msg->timeout);
+	if (!rc) {
+		struct output *resp = bp->hwrm_cmd_resp_addr;
+		u32 len = le16_to_cpu(resp->resp_len);
+
+		if (fw_msg->resp_max_len < len)
+			len = fw_msg->resp_max_len;
+
+		memcpy(fw_msg->resp, resp, len);
+	}
+	mutex_unlock(&bp->hwrm_cmd_lock);
+	return rc;
+}
+
+static void bnxt_ulp_get(struct bnxt_ulp *ulp)
+{
+	atomic_inc(&ulp->ref_count);
+}
+
+static void bnxt_ulp_put(struct bnxt_ulp *ulp)
+{
+	atomic_dec(&ulp->ref_count);
+}
+
+void bnxt_ulp_stop(struct bnxt *bp)
+{
+	struct bnxt_en_dev *edev = bp->edev;
+	struct bnxt_ulp_ops *ops;
+	int i;
+
+	if (!edev)
+		return;
+
+	for (i = 0; i < BNXT_MAX_ULP; i++) {
+		struct bnxt_ulp *ulp = &edev->ulp_tbl[i];
+
+		ops = rtnl_dereference(ulp->ulp_ops);
+		if (!ops || !ops->ulp_stop)
+			continue;
+		ops->ulp_stop(ulp->handle);
+	}
+}
+
+void bnxt_ulp_start(struct bnxt *bp)
+{
+	struct bnxt_en_dev *edev = bp->edev;
+	struct bnxt_ulp_ops *ops;
+	int i;
+
+	if (!edev)
+		return;
+
+	for (i = 0; i < BNXT_MAX_ULP; i++) {
+		struct bnxt_ulp *ulp = &edev->ulp_tbl[i];
+
+		ops = rtnl_dereference(ulp->ulp_ops);
+		if (!ops || !ops->ulp_start)
+			continue;
+		ops->ulp_start(ulp->handle);
+	}
+}
+
+void bnxt_ulp_sriov_cfg(struct bnxt *bp, int num_vfs)
+{
+	struct bnxt_en_dev *edev = bp->edev;
+	struct bnxt_ulp_ops *ops;
+	int i;
+
+	if (!edev)
+		return;
+
+	for (i = 0; i < BNXT_MAX_ULP; i++) {
+		struct bnxt_ulp *ulp = &edev->ulp_tbl[i];
+
+		rcu_read_lock();
+		ops = rcu_dereference(ulp->ulp_ops);
+		if (!ops || !ops->ulp_sriov_config) {
+			rcu_read_unlock();
+			continue;
+		}
+		bnxt_ulp_get(ulp);
+		rcu_read_unlock();
+		ops->ulp_sriov_config(ulp->handle, num_vfs);
+		bnxt_ulp_put(ulp);
+	}
+}
+
+void bnxt_ulp_async_events(struct bnxt *bp, struct hwrm_async_event_cmpl *cmpl)
+{
+	u16 event_id = le16_to_cpu(cmpl->event_id);
+	struct bnxt_en_dev *edev = bp->edev;
+	struct bnxt_ulp_ops *ops;
+	int i;
+
+	if (!edev)
+		return;
+
+	rcu_read_lock();
+	for (i = 0; i < BNXT_MAX_ULP; i++) {
+		struct bnxt_ulp *ulp = &edev->ulp_tbl[i];
+
+		ops = rcu_dereference(ulp->ulp_ops);
+		if (!ops || !ops->ulp_async_notifier)
+			continue;
+		if (!ulp->async_events_bmap ||
+		    event_id > ulp->max_async_event_id)
+			continue;
+
+		/* Read max_async_event_id first before testing the bitmap. */
+		smp_rmb();
+		if (test_bit(event_id, ulp->async_events_bmap))
+			ops->ulp_async_notifier(ulp->handle, cmpl);
+	}
+	rcu_read_unlock();
+}
+
+static int bnxt_register_async_events(struct bnxt_en_dev *edev, int ulp_id,
+				      unsigned long *events_bmap, u16 max_id)
+{
+	struct net_device *dev = edev->net;
+	struct bnxt *bp = netdev_priv(dev);
+	struct bnxt_ulp *ulp;
+
+	if (ulp_id >= BNXT_MAX_ULP)
+		return -EINVAL;
+
+	ulp = &edev->ulp_tbl[ulp_id];
+	ulp->async_events_bmap = events_bmap;
+	/* Make sure bnxt_ulp_async_events() sees this order */
+	smp_wmb();
+	ulp->max_async_event_id = max_id;
+	bnxt_hwrm_func_rgtr_async_events(bp, events_bmap, max_id + 1);
+	return 0;
+}
+
+static const struct bnxt_en_ops bnxt_en_ops_tbl = {
+	.bnxt_register_device	= bnxt_register_dev,
+	.bnxt_unregister_device	= bnxt_unregister_dev,
+	.bnxt_request_msix	= bnxt_req_msix_vecs,
+	.bnxt_free_msix		= bnxt_free_msix_vecs,
+	.bnxt_send_fw_msg	= bnxt_send_msg,
+	.bnxt_register_fw_async_events	= bnxt_register_async_events,
+};
+
+struct bnxt_en_dev *bnxt_ulp_probe(struct net_device *dev)
+{
+	struct bnxt *bp = netdev_priv(dev);
+	struct bnxt_en_dev *edev;
+
+	edev = bp->edev;
+	if (!edev) {
+		edev = kzalloc(sizeof(*edev), GFP_KERNEL);
+		if (!edev)
+			return ERR_PTR(-ENOMEM);
+		edev->en_ops = &bnxt_en_ops_tbl;
+		if (bp->flags & BNXT_FLAG_ROCEV1_CAP)
+			edev->flags |= BNXT_EN_FLAG_ROCEV1_CAP;
+		if (bp->flags & BNXT_FLAG_ROCEV2_CAP)
+			edev->flags |= BNXT_EN_FLAG_ROCEV2_CAP;
+		edev->net = dev;
+		edev->pdev = bp->pdev;
+		bp->edev = edev;
+	}
+	return bp->edev;
+}