Merge branch 'greg-throttling'

Add a tool to control Rx bandwidth throttling of the traffic that goes
from WR ports to Linux. It configures the FPGA module with a maximum allowed
bandwidth in KB/s. Throttling can be enabled to prevent Linux using 100% of
the processing power to receive Ethernet frames coming from WR ports to the
CPU.

Signed-off-by: Adam Wujek <adam.wujek@cern.ch>

Kconfig

@@ -754,7 +754,22 @@ config WRSAUXCLK_PPSHIFT
 	  should be re-calibrated. Otherwise, 1-PPS output will be shifted
 	  from the WR timescale by <steps>*150ps.
 
+endmenu
 
+menu "NIC throttling configuration"
+config NIC_THROTTLING_ENABLED
+	bool "Enable NIC throttling"
+	default n
+	help
+	  Limit bandwith on NIC
+
+config NIC_THROTTLING_VAL
+	int "NIC throttling value"
+	depends on NIC_THROTTLING_ENABLED
+	default "4000"
+	range 1 65535
+	help
+	  Value to which bandwith should be limited
 
 endmenu
 

doc/wrs-user-manual.in

@@ -1283,6 +1283,13 @@ The following tools and scripts are provided:
 	transactions. The race can cause errors while reading SFPs memory,
 	wrong notification of LEDs, the false insert/remove SFP notifications.
 
+@item wrs_throttling
+  The tool is used to control Rx bandwidth throttling of the traffic that goes
+  from WR ports to Linux. It configures the FPGA module with a maximum allowed
+  bandwidth in KB/s. Throttling can be enabled to prevent Linux using 100% of
+  the processing power to receive Ethernet frames coming from WR ports to the
+  CPU.
+
 @c FIXME: document lm32-vuart rtu_stat spll_dbg_proxy
 @c FIXME: document wrs_pstats
 @end table

kernel/wr_nic/device.c

@@ -139,7 +139,7 @@ static int wrn_probe(struct platform_device *pdev)
 	wrn->ppsg_regs = wrn->bases[WRN_FB_PPSG];
 	wrn->txd = ((void *)wrn->regs) + 0x80; /* was: TX1_D1 */
 	wrn->rxd = ((void *)wrn->regs) + 0x100; /* was: RX1_D1 */
-	wrn->databuf = (void *)wrn->regs + offsetof(struct NIC_WB, MEM);
+	wrn->databuf = (void *)wrn->regs + NIC_MEM_BASE;
 	tasklet_init(&wrn->rx_tlet, wrn_rx_interrupt, (unsigned long)wrn);
 	if (0)
 		printk("regs %p, txd %p, rxd %p, buffer %p\n",

kernel/wr_nic/nic-mem.h

@@ -11,6 +11,9 @@
 #include "wr-nic.h"
 #include <asm/unaligned.h>
 
+#define NIC_MEM_BASE 0x8000 /* byte addressing of wb_in.adr(13) that in HDL
+			     * selects between WB registers and nic_buffer */
+
 /* Descriptor direction, used to locate descriptror data memory */
 enum wrn_ddir {
     WRN_DDIR_RX,

userspace/include/fpga_io.h

@@ -38,6 +38,9 @@
 /* Endpoint  */
 #define FPGA_BASE_EP0          0x30000
 
+/* NIC */
+#define FPGA_BASE_NIC          0x20000
+
 extern volatile uint8_t        *_fpga_base_virt; /* libwr/fpga_io.c */
 
 #define FPGA_BASE_ADDR          _fpga_base_virt

userspace/rootfs_override/etc/init.d/wrs_throttling.sh

+#!/bin/sh
+
+# this script shall be called before enabling the switching
+dotconfig=/wr/etc/dot-config
+
+set -o pipefail
+
+start() {
+    if [ -f $dotconfig ]; then
+	. $dotconfig
+    else
+	echo "$0 unable to start wrs_throttling, unable to source " \
+	      "dot-config ($dotconfig)!"
+	exit 1
+    fi
+
+    WRS_LOG=$CONFIG_WRS_LOG_OTHER
+
+    # if empty turn it to /dev/null
+    if [ -z $WRS_LOG ]; then
+	WRS_LOG="/dev/null";
+    fi
+
+    # if a pathname, use it
+    if echo "$WRS_LOG" | grep / > /dev/null; then
+	eval LOGPIPE=\" \> $WRS_LOG 2\>\&1 \";
+    else
+	# not a pathname: use verbatim
+	eval LOGPIPE=\" 2\>\&1 \| logger -t wr-switch -p $WRS_LOG\"
+    fi
+
+    echo -n "Starting wrs_throttling: "
+    if [ "$CONFIG_NIC_THROTTLING_ENABLED" = "y" ] \
+      && [ ! -z "$CONFIG_NIC_THROTTLING_VAL" ] ; then
+	eval /wr/bin/wrs_throttling -t "$CONFIG_NIC_THROTTLING_VAL" $LOGPIPE
+	ret=$?
+	if [ $ret -eq 0 ]; then
+	    echo "OK"
+	else
+	    echo "Failed"
+	fi
+    else
+	echo "throttling disabled"
+    fi
+
+}
+
+stop() {
+    echo -n "Stopping wrs_throttling: "
+    eval /wr/bin/wrs_throttling -d $LOGPIPE
+    ret=$?
+    if [ $ret -eq 0 ]; then
+	echo "OK"
+    else
+	echo "Failed"
+    fi
+}
+
+restart() {
+    stop
+    start
+}
+
+case "$1" in
+  start)
+	start
+	;;
+  stop)
+	stop
+	;;
+  restart|reload)
+	restart
+	;;
+  *)
+	echo $"Usage: $0 {start|stop|restart}"
+	exit 1
+	;;
+esac

userspace/rootfs_override/etc/rcS/S62wrs_throttling.sh

+../init.d/wrs_throttling.sh
\ No newline at end of file

userspace/tools/.gitignore

@@ -24,3 +24,4 @@ mkpasswd
 wrs_status_led
 wrs_sfp_dump
 wrs_pps_control
+wrs_throttling

userspace/tools/Makefile

@@ -9,6 +9,7 @@ TOOLS += wrs_checkcfg
 TOOLS += wrs_status_led
 TOOLS += mkpasswd
 TOOLS += wrs_sfp_dump
+TOOLS += wrs_throttling
 PPSI_CONFIG = ../ppsi/include/generated/autoconf.h
 
 WR_INSTALL_ROOT ?= /usr/lib/white-rabbit

userspace/tools/wrs_throttling.c

+/*
+ * Copyright (c) 2016, CERN
+ *
+ * Author: Grzegorz Daniluk <grzegorz.daniluk@cern.ch>
+ *
+ * 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, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include <stdio.h>
+#include <getopt.h>
+#include <inttypes.h>
+#include <stddef.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <sys/stat.h>
+
+#include <libwr/switch_hw.h>
+#include <libwr/wrs-msg.h>
+#include <fpga_io.h>
+#include <regs/nic-regs.h>
+
+#define nic_write(reg, val) \
+	_fpga_writel(FPGA_BASE_NIC + offsetof(struct NIC_WB, reg), val)
+
+#define nic_read(reg) \
+	_fpga_readl(FPGA_BASE_NIC + offsetof(struct NIC_WB, reg))
+
+#define MAX_THR 65535	/* b/w thr in HDL is 16-bit value in KB/s */
+#define MIN_THR 2
+
+static char *prgname;
+
+void enable_throttling(int en)
+{
+	uint32_t val;
+
+	val = nic_read(CR);
+	if (en) {
+		val |= NIC_CR_RXTHR_EN;
+		printf("NIC bandwidth throttling enabled\n");
+	} else {
+		val &= (~NIC_CR_RXTHR_EN);
+		printf("NIC bandwidth throttling disabled\n");
+	}
+
+	nic_write(CR, val);
+}
+
+void print_bw(int print_bps)
+{
+	uint32_t bw;
+
+	/* first we read the b/w in Bytes/s */
+	bw = nic_read(RXBW);
+
+	if (print_bps)
+		printf("NIC Rx bandwidth: %u B/s\n", bw);
+	else
+		printf("NIC Rx bandwidth: %.3f KB/s\n", bw/1024.0);
+}
+
+int set_thr(unsigned thr)
+{
+	if (thr > MAX_THR || thr < MIN_THR)
+		return -1;
+
+	printf("Setting NIC Rx bandwidth threshold: %u KB/s\n", thr);
+	nic_write(MAXRXBW, thr);
+
+	return 0;
+}
+
+void print_settings(void)
+{
+	uint32_t en;
+
+	en = nic_read(CR) & NIC_CR_RXTHR_EN;
+	printf("Current settings:\n");
+	printf("Throttling:    %s\n", en ? "enabled" : "disabled");
+	printf("Max bandwidth: %u KB/s\n", nic_read(MAXRXBW));
+}
+
+void print_help(char *prgname)
+{
+	printf("wrs_throttling. Commit %s, built on " __DATE__ "\n",
+	       __GIT_VER__);
+	printf("usage: %s <options>\n", prgname);
+	printf("   -h         Show this help message\n"
+		"   -b         Print current b/w in B/s (KB/s by default)\n"
+		"   -l         Endless loop mode. Prints the current b/w "
+		"every 1 s\n"
+		"   -t <KB/s>  Set maximum NIC Rx bandwidth to <KB/s>\n"
+		"   -d         Disable b/w throttling in NIC\n"
+		"   -s         Print current settings of the throttling\n");
+}
+
+int main(int argc, char *argv[])
+{
+	int c = 0;
+	int print_bps = 0;	/* print current b/w in Bytes/s */
+	int loop_mode = 0;	/* prints current b/w every 1s */
+
+	prgname = argv[0];
+
+
+	wrs_msg_init(argc, argv);
+
+	if (shw_fpga_mmap_init() < 0) {
+		pr_error("%s: Can't access device memory\n", prgname);
+		exit(1);
+	}
+
+	while ((c = getopt(argc, argv, "hbt:lds")) != -1) {
+		switch (c) {
+		case 'b':
+			/* print current b/w in B/s */
+			print_bps = 1;
+			break;
+		case 't':
+			/* set b/w threshold */
+			if (set_thr(atoi(optarg)) != -1) {
+				enable_throttling(1);
+			} else {
+				pr_error("Threshold outside allowed range "
+					"<%d; %d>\n", MIN_THR, MAX_THR);
+			}
+			break;
+		case 'd':
+			/* disable b/w throttling */
+			enable_throttling(0);
+			break;
+		case 'l':
+			loop_mode = 1;
+			break;
+		case 's':
+			print_settings();
+			break;
+		case 'h':
+		default:
+			print_help(prgname);
+			exit(1);
+		}
+	}
+
+	/* do actual printing */
+	print_bw(print_bps);
+	while (loop_mode) {
+		sleep(1);
+		print_bw(print_bps);
+	}
+
+	return 0;
+}