[intel] Add support for mailbox used by virtual functions

Virtual functions use a mailbox to communicate with the physical
function driver: this covers functionality such as obtaining the MAC
address.

Signed-off-by: Michael Brown <mcb30@ipxe.org>

src/drivers/net/intel.h

@@ -243,6 +243,29 @@ intel_init_ring ( struct intel_ring *ring, unsigned int count, unsigned int reg,
 	ring->describe = describe;
 }
 
+/** An Intel virtual function mailbox */
+struct intel_mailbox {
+	/** Mailbox control register */
+	unsigned int ctrl;
+	/** Mailbox memory base */
+	unsigned int mem;
+};
+
+/**
+ * Initialise mailbox
+ *
+ * @v mbox		Mailbox
+ * @v ctrl		Mailbox control register
+ * @v mem		Mailbox memory register base
+ */
+static inline __attribute__ (( always_inline )) void
+intel_init_mbox ( struct intel_mailbox *mbox, unsigned int ctrl,
+		  unsigned int mem ) {
+
+	mbox->ctrl = ctrl;
+	mbox->mem = mem;
+}
+
 /** An Intel network card */
 struct intel_nic {
 	/** Registers */
@@ -261,6 +284,9 @@ struct intel_nic {
 	/** EEPROM address shift */
 	unsigned int eerd_addr_shift;
 
+	/** Mailbox */
+	struct intel_mailbox mbox;
+
 	/** Transmit descriptor ring */
 	struct intel_ring tx;
 	/** Receive descriptor ring */

src/drivers/net/intelvf.c

@@ -0,0 +1,303 @@
+/*
+ * Copyright (C) 2015 Michael Brown <mbrown@fensystems.co.uk>.
+ *
+ * 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; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
+ * 02110-1301, USA.
+ *
+ * You can also choose to distribute this program under the terms of
+ * the Unmodified Binary Distribution Licence (as given in the file
+ * COPYING.UBDL), provided that you have satisfied its requirements.
+ */
+
+FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
+
+#include <string.h>
+#include <unistd.h>
+#include <errno.h>
+#include <ipxe/io.h>
+#include <ipxe/netdevice.h>
+#include <ipxe/ethernet.h>
+#include "intelvf.h"
+
+/** @file
+ *
+ * Intel 10/100/1000 virtual function network card driver
+ *
+ */
+
+/******************************************************************************
+ *
+ * Mailbox messages
+ *
+ ******************************************************************************
+ */
+
+/**
+ * Write message to mailbox
+ *
+ * @v intel		Intel device
+ * @v msg		Message
+ */
+static void intelvf_mbox_write ( struct intel_nic *intel,
+				 const union intelvf_msg *msg ) {
+	unsigned int i;
+
+	/* Write message */
+	DBGC2 ( intel, "INTEL %p sending message", intel );
+	for ( i = 0 ; i < ( sizeof ( *msg ) / sizeof ( msg->dword[0] ) ) ; i++){
+		DBGC2 ( intel, "%c%08x", ( i ? ':' : ' ' ), msg->dword[i] );
+		writel ( msg->dword[i], ( intel->regs + intel->mbox.mem +
+					  ( i * sizeof ( msg->dword[0] ) ) ) );
+	}
+	DBGC2 ( intel, "\n" );
+}
+
+/**
+ * Read message from mailbox
+ *
+ * @v intel		Intel device
+ * @v msg		Message
+ */
+static void intelvf_mbox_read ( struct intel_nic *intel,
+				union intelvf_msg *msg ) {
+	unsigned int i;
+
+	/* Read message */
+	DBGC2 ( intel, "INTEL %p received message", intel );
+	for ( i = 0 ; i < ( sizeof ( *msg ) / sizeof ( msg->dword[0] ) ) ; i++){
+		msg->dword[i] = readl ( intel->regs + intel->mbox.mem +
+					( i * sizeof ( msg->dword[0] ) ) );
+		DBGC2 ( intel, "%c%08x", ( i ? ':' : ' ' ), msg->dword[i] );
+	}
+	DBGC2 ( intel, "\n" );
+}
+
+/**
+ * Poll mailbox
+ *
+ * @v intel		Intel device
+ * @ret rc		Return status code
+ *
+ * Note that polling the mailbox may fail if the underlying PF is
+ * reset.
+ */
+int intelvf_mbox_poll ( struct intel_nic *intel ) {
+	struct intel_mailbox *mbox = &intel->mbox;
+	union intelvf_msg msg;
+	uint32_t ctrl;
+
+	/* Get mailbox status */
+	ctrl = readl ( intel->regs + mbox->ctrl );
+
+	/* Fail if a reset is in progress */
+	if ( ctrl & INTELVF_MBCTRL_RSTI )
+		return -EPIPE;
+
+	/* Acknowledge (and ignore) any received messages */
+	if ( ctrl & INTELVF_MBCTRL_PFSTS ) {
+		intelvf_mbox_read ( intel, &msg );
+		writel ( INTELVF_MBCTRL_ACK, intel->regs + mbox->ctrl );
+	}
+
+	return 0;
+}
+
+/**
+ * Wait for PF reset to complete
+ *
+ * @v intel		Intel device
+ * @ret rc		Return status code
+ */
+int intelvf_mbox_wait ( struct intel_nic *intel ) {
+	unsigned int i;
+	int rc;
+
+	/* Wait until a poll completes successfully */
+	for ( i = 0 ; i < INTELVF_MBOX_MAX_WAIT_MS ; i++ ) {
+
+		/* Check for successful poll */
+		if ( ( rc = intelvf_mbox_poll ( intel ) ) == 0 )
+			return 0;
+
+		/* Delay */
+		mdelay ( 1 );
+	}
+
+	DBGC ( intel, "INTEL %p timed out waiting for reset\n", intel );
+	return -ETIMEDOUT;
+}
+
+/**
+ * Send/receive mailbox message
+ *
+ * @v intel		Intel device
+ * @v msg		Message buffer
+ * @ret rc		Return status code
+ */
+static int intelvf_mbox_msg ( struct intel_nic *intel,
+			      union intelvf_msg *msg ) {
+	struct intel_mailbox *mbox = &intel->mbox;
+	uint32_t ctrl;
+	uint32_t seen = 0;
+	unsigned int i;
+
+	/* Sanity check */
+	assert ( ! ( msg->hdr & INTELVF_MSG_RESPONSE ) );
+
+	/* Handle mailbox */
+	for ( i = 0 ; i < INTELVF_MBOX_MAX_WAIT_MS ; i++ ) {
+
+		/* Attempt to claim mailbox, if we have not yet sent
+		 * our message.
+		 */
+		if ( ! ( seen & INTELVF_MBCTRL_VFU ) )
+			writel ( INTELVF_MBCTRL_VFU, intel->regs + mbox->ctrl );
+
+		/* Get mailbox status and record observed flags */
+		ctrl = readl ( intel->regs + mbox->ctrl );
+		seen |= ctrl;
+
+		/* If a reset is in progress, clear VFU and abort */
+		if ( ctrl & INTELVF_MBCTRL_RSTI ) {
+			writel ( 0, intel->regs + mbox->ctrl );
+			return -EPIPE;
+		}
+
+		/* Write message to mailbox, if applicable.  This
+		 * potentially overwrites a message sent by the PF (if
+		 * the PF has simultaneously released PFU (thus
+		 * allowing our VFU) and asserted PFSTS), but that
+		 * doesn't really matter since there are no
+		 * unsolicited PF->VF messages that require the actual
+		 * message content to be observed.
+		 */
+		if ( ctrl & INTELVF_MBCTRL_VFU )
+			intelvf_mbox_write ( intel, msg );
+
+		/* Read message from mailbox, if applicable. */
+		if ( ( seen & INTELVF_MBCTRL_VFU ) &&
+		     ( seen & INTELVF_MBCTRL_PFACK ) &&
+		     ( ctrl & INTELVF_MBCTRL_PFSTS ) )
+			intelvf_mbox_read ( intel, msg );
+
+		/* Acknowledge received message (if applicable),
+		 * release VFU lock, and send message (if applicable).
+		 */
+		ctrl = ( ( ( ctrl & INTELVF_MBCTRL_PFSTS ) ?
+			   INTELVF_MBCTRL_ACK : 0 ) |
+			 ( ( ctrl & INTELVF_MBCTRL_VFU ) ?
+			   INTELVF_MBCTRL_REQ : 0 ) );
+		writel ( ctrl, intel->regs + mbox->ctrl );
+
+		/* Exit successfully if we have received a response */
+		if ( msg->hdr & INTELVF_MSG_RESPONSE ) {
+
+			/* Sanity check */
+			assert ( seen & INTELVF_MBCTRL_VFU );
+			assert ( seen & INTELVF_MBCTRL_PFACK );
+			assert ( seen & INTELVF_MBCTRL_PFSTS );
+
+			return 0;
+		}
+
+		/* Delay */
+		mdelay ( 1 );
+	}
+
+	DBGC ( intel, "INTEL %p timed out waiting for mailbox (seen %08x)\n",
+	       intel, seen );
+	return -ETIMEDOUT;
+}
+
+/**
+ * Send reset message and get initial MAC address
+ *
+ * @v intel		Intel device
+ * @v hw_addr		Hardware address to fill in, or NULL
+ * @ret rc		Return status code
+ */
+int intelvf_mbox_reset ( struct intel_nic *intel, uint8_t *hw_addr ) {
+	union intelvf_msg msg;
+	int rc;
+
+	/* Send reset message */
+	memset ( &msg, 0, sizeof ( msg ) );
+	msg.hdr = INTELVF_MSG_TYPE_RESET;
+	if ( ( rc = intelvf_mbox_msg ( intel, &msg ) ) != 0 ) {
+		DBGC ( intel, "INTEL %p reset failed: %s\n",
+		       intel, strerror ( rc ) );
+		return rc;
+	}
+
+	/* Check response */
+	if ( ( msg.hdr & INTELVF_MSG_TYPE_MASK ) != INTELVF_MSG_TYPE_RESET ) {
+		DBGC ( intel, "INTEL %p reset unexpected response:\n", intel );
+		DBGC_HDA ( intel, 0, &msg, sizeof ( msg ) );
+		return -EPROTO;
+	}
+
+	/* Fill in MAC address, if applicable */
+	if ( hw_addr ) {
+		if ( msg.hdr & INTELVF_MSG_ACK ) {
+			memcpy ( hw_addr, msg.mac.mac, sizeof ( msg.mac.mac ) );
+			DBGC ( intel, "INTEL %p reset assigned MAC address "
+			       "%s\n", intel, eth_ntoa ( hw_addr ) );
+		} else {
+			eth_random_addr ( hw_addr );
+			DBGC ( intel, "INTEL %p reset generated MAC address "
+			       "%s\n", intel, eth_ntoa ( hw_addr ) );
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * Send set MAC address message
+ *
+ * @v intel		Intel device
+ * @v ll_addr		Link-layer address
+ * @ret rc		Return status code
+ */
+int intelvf_mbox_set_mac ( struct intel_nic *intel, const uint8_t *ll_addr ) {
+	union intelvf_msg msg;
+	int rc;
+
+	/* Send set MAC address message */
+	memset ( &msg, 0, sizeof ( msg ) );
+	msg.hdr = INTELVF_MSG_TYPE_SET_MAC;
+	memcpy ( msg.mac.mac, ll_addr, sizeof ( msg.mac.mac ) );
+	if ( ( rc = intelvf_mbox_msg ( intel, &msg ) ) != 0 ) {
+		DBGC ( intel, "INTEL %p set MAC address failed: %s\n",
+		       intel, strerror ( rc ) );
+		return rc;
+	}
+
+	/* Check response */
+	if ( ( msg.hdr & INTELVF_MSG_TYPE_MASK ) != INTELVF_MSG_TYPE_SET_MAC ) {
+		DBGC ( intel, "INTEL %p set MAC address unexpected response:\n",
+		       intel );
+		DBGC_HDA ( intel, 0, &msg, sizeof ( msg ) );
+		return -EPROTO;
+	}
+
+	/* Check that we were allowed to set the MAC address */
+	if ( ! ( msg.hdr & INTELVF_MSG_ACK ) ) {
+		DBGC ( intel, "INTEL %p set MAC address refused\n", intel );
+		return -EPERM;
+	}
+
+	return 0;
+}