octeontx2-pf: Mailbox communication with AF

In the resource virtualization unit (RVU) each of the PF and AF
(admin function) share a 64KB of reserved memory region for
communication. This patch initializes PF <=> AF mailbox IRQs,
registers handlers for processing these communication messages.
Also adds support to process these messages in both directions
ie responses to PF initiated DOWN (PF => AF) messages and AF
initiated UP messages (AF => PF).

Mbox communication APIs and message formats are defined in AF driver
(drivers/net/ethernet/marvell/octeontx2/af), mbox.h from AF driver is
included here to avoid duplication.
Signed-off-by: Geetha sowjanya <gakula@marvell.com>
Signed-off-by: Christina Jacob <cjacob@marvell.com>
Signed-off-by: Subbaraya Sundeep <sbhatta@marvell.com>
Signed-off-by: Aleksey Makarov <amakarov@marvell.com>
Signed-off-by: Sunil Goutham <sgoutham@marvell.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/marvell/octeontx2/nic/Makefile

@@ -5,6 +5,6 @@
 
 obj-$(CONFIG_OCTEONTX2_PF) += octeontx2_nicpf.o
 
-octeontx2_nicpf-y := otx2_pf.o
+octeontx2_nicpf-y := otx2_pf.o otx2_common.o
 
 ccflags-y += -I$(srctree)/drivers/net/ethernet/marvell/octeontx2/af

drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.c

+// SPDX-License-Identifier: GPL-2.0
+/* Marvell OcteonTx2 RVU Ethernet driver
+ *
+ * Copyright (C) 2020 Marvell International Ltd.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/interrupt.h>
+#include <linux/pci.h>
+
+#include "otx2_reg.h"
+#include "otx2_common.h"
+
+#define M(_name, _id, _fn_name, _req_type, _rsp_type)			\
+int __weak								\
+otx2_mbox_up_handler_ ## _fn_name(struct otx2_nic *pfvf,		\
+				struct _req_type *req,			\
+				struct _rsp_type *rsp)			\
+{									\
+	/* Nothing to do here */					\
+	return 0;							\
+}									\
+EXPORT_SYMBOL(otx2_mbox_up_handler_ ## _fn_name);
+MBOX_UP_CGX_MESSAGES
+#undef M

drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.h

@@ -13,6 +13,7 @@
 
 #include <linux/pci.h>
 
+#include <mbox.h>
 #include "otx2_reg.h"
 
 /* PCI device IDs */
@@ -20,12 +21,31 @@
 
 /* PCI BAR nos */
 #define PCI_CFG_REG_BAR_NUM                     2
+#define PCI_MBOX_BAR_NUM                        4
+
+#define NAME_SIZE                               32
+
+struct mbox {
+	struct otx2_mbox	mbox;
+	struct work_struct	mbox_wrk;
+	struct otx2_mbox	mbox_up;
+	struct work_struct	mbox_up_wrk;
+	struct otx2_nic		*pfvf;
+	void			*bbuf_base; /* Bounce buffer for mbox memory */
+	struct mutex		lock;	/* serialize mailbox access */
+	int			num_msgs; /* mbox number of messages */
+	int			up_num_msgs; /* mbox_up number of messages */
+};
 
 struct otx2_hw {
 	struct pci_dev		*pdev;
 	u16                     rx_queues;
 	u16                     tx_queues;
 	u16			max_queues;
+
+	/* MSI-X */
+	char			*irq_name;
+	cpumask_var_t           *affinity_mask;
 };
 
 struct otx2_nic {
@@ -35,6 +55,12 @@ struct otx2_nic {
 	struct otx2_hw		hw;
 	struct pci_dev		*pdev;
 	struct device		*dev;
+
+	/* Mbox */
+	struct mbox		mbox;
+	struct workqueue_struct *mbox_wq;
+
+	u16			pcifunc; /* RVU PF_FUNC */
 };
 
 /* Register read/write APIs */
@@ -74,4 +100,144 @@ static inline u64 otx2_read64(struct otx2_nic *nic, u64 offset)
 	return readq(addr);
 }
 
+/* Mbox bounce buffer APIs */
+static inline int otx2_mbox_bbuf_init(struct mbox *mbox, struct pci_dev *pdev)
+{
+	struct otx2_mbox *otx2_mbox;
+	struct otx2_mbox_dev *mdev;
+
+	mbox->bbuf_base = devm_kmalloc(&pdev->dev, MBOX_SIZE, GFP_KERNEL);
+	if (!mbox->bbuf_base)
+		return -ENOMEM;
+
+	/* Overwrite mbox mbase to point to bounce buffer, so that PF/VF
+	 * prepare all mbox messages in bounce buffer instead of directly
+	 * in hw mbox memory.
+	 */
+	otx2_mbox = &mbox->mbox;
+	mdev = &otx2_mbox->dev[0];
+	mdev->mbase = mbox->bbuf_base;
+
+	otx2_mbox = &mbox->mbox_up;
+	mdev = &otx2_mbox->dev[0];
+	mdev->mbase = mbox->bbuf_base;
+	return 0;
+}
+
+static inline void otx2_sync_mbox_bbuf(struct otx2_mbox *mbox, int devid)
+{
+	u16 msgs_offset = ALIGN(sizeof(struct mbox_hdr), MBOX_MSG_ALIGN);
+	void *hw_mbase = mbox->hwbase + (devid * MBOX_SIZE);
+	struct otx2_mbox_dev *mdev = &mbox->dev[devid];
+	struct mbox_hdr *hdr;
+	u64 msg_size;
+
+	if (mdev->mbase == hw_mbase)
+		return;
+
+	hdr = hw_mbase + mbox->rx_start;
+	msg_size = hdr->msg_size;
+
+	if (msg_size > mbox->rx_size - msgs_offset)
+		msg_size = mbox->rx_size - msgs_offset;
+
+	/* Copy mbox messages from mbox memory to bounce buffer */
+	memcpy(mdev->mbase + mbox->rx_start,
+	       hw_mbase + mbox->rx_start, msg_size + msgs_offset);
+}
+
+static inline void otx2_mbox_lock_init(struct mbox *mbox)
+{
+	mutex_init(&mbox->lock);
+}
+
+static inline void otx2_mbox_lock(struct mbox *mbox)
+{
+	mutex_lock(&mbox->lock);
+}
+
+static inline void otx2_mbox_unlock(struct mbox *mbox)
+{
+	mutex_unlock(&mbox->lock);
+}
+
+/* Mbox APIs */
+static inline int otx2_sync_mbox_msg(struct mbox *mbox)
+{
+	int err;
+
+	if (!otx2_mbox_nonempty(&mbox->mbox, 0))
+		return 0;
+	otx2_mbox_msg_send(&mbox->mbox, 0);
+	err = otx2_mbox_wait_for_rsp(&mbox->mbox, 0);
+	if (err)
+		return err;
+
+	return otx2_mbox_check_rsp_msgs(&mbox->mbox, 0);
+}
+
+static inline int otx2_sync_mbox_up_msg(struct mbox *mbox, int devid)
+{
+	int err;
+
+	if (!otx2_mbox_nonempty(&mbox->mbox_up, devid))
+		return 0;
+	otx2_mbox_msg_send(&mbox->mbox_up, devid);
+	err = otx2_mbox_wait_for_rsp(&mbox->mbox_up, devid);
+	if (err)
+		return err;
+
+	return otx2_mbox_check_rsp_msgs(&mbox->mbox_up, devid);
+}
+
+/* Use this API to send mbox msgs in atomic context
+ * where sleeping is not allowed
+ */
+static inline int otx2_sync_mbox_msg_busy_poll(struct mbox *mbox)
+{
+	int err;
+
+	if (!otx2_mbox_nonempty(&mbox->mbox, 0))
+		return 0;
+	otx2_mbox_msg_send(&mbox->mbox, 0);
+	err = otx2_mbox_busy_poll_for_rsp(&mbox->mbox, 0);
+	if (err)
+		return err;
+
+	return otx2_mbox_check_rsp_msgs(&mbox->mbox, 0);
+}
+
+#define M(_name, _id, _fn_name, _req_type, _rsp_type)                   \
+static struct _req_type __maybe_unused					\
+*otx2_mbox_alloc_msg_ ## _fn_name(struct mbox *mbox)                    \
+{									\
+	struct _req_type *req;						\
+									\
+	req = (struct _req_type *)otx2_mbox_alloc_msg_rsp(		\
+		&mbox->mbox, 0, sizeof(struct _req_type),		\
+		sizeof(struct _rsp_type));				\
+	if (!req)							\
+		return NULL;						\
+	req->hdr.sig = OTX2_MBOX_REQ_SIG;				\
+	req->hdr.id = _id;						\
+	return req;							\
+}
+
+MBOX_MESSAGES
+#undef M
+
+#define M(_name, _id, _fn_name, _req_type, _rsp_type)			\
+int									\
+otx2_mbox_up_handler_ ## _fn_name(struct otx2_nic *pfvf,		\
+				struct _req_type *req,			\
+				struct _rsp_type *rsp);			\
+
+MBOX_UP_CGX_MESSAGES
+#undef M
+
+#define	RVU_PFVF_PF_SHIFT	10
+#define	RVU_PFVF_PF_MASK	0x3F
+#define	RVU_PFVF_FUNC_SHIFT	0
+#define	RVU_PFVF_FUNC_MASK	0x3FF
+
 #endif /* OTX2_COMMON_H */