/*
 * sctp_offload - GRO/GSO Offloading for SCTP
 *
 * Copyright (C) 2015, Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
 *
 * 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.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/kprobes.h>
#include <linux/socket.h>
#include <linux/sctp.h>
#include <linux/proc_fs.h>
#include <linux/vmalloc.h>
#include <linux/module.h>
#include <linux/kfifo.h>
#include <linux/time.h>
#include <net/net_namespace.h>

#include <linux/skbuff.h>
#include <net/sctp/sctp.h>
#include <net/sctp/checksum.h>
#include <net/protocol.h>

static __le32 sctp_gso_make_checksum(struct sk_buff *skb)
{
	skb->ip_summed = CHECKSUM_NONE;
	return sctp_compute_cksum(skb, skb_transport_offset(skb));
}

static struct sk_buff *sctp_gso_segment(struct sk_buff *skb,
					netdev_features_t features)
{
	struct sk_buff *segs = ERR_PTR(-EINVAL);
	struct sctphdr *sh;

	sh = sctp_hdr(skb);
	if (!pskb_may_pull(skb, sizeof(*sh)))
		goto out;

	__skb_pull(skb, sizeof(*sh));

	if (skb_gso_ok(skb, features | NETIF_F_GSO_ROBUST)) {
		/* Packet is from an untrusted source, reset gso_segs. */
		struct skb_shared_info *pinfo = skb_shinfo(skb);
		struct sk_buff *frag_iter;

		pinfo->gso_segs = 0;
		if (skb->len != skb->data_len) {
			/* Means we have chunks in here too */
			pinfo->gso_segs++;
		}

		skb_walk_frags(skb, frag_iter)
			pinfo->gso_segs++;

		segs = NULL;
		goto out;
	}

	segs = skb_segment(skb, features | NETIF_F_HW_CSUM);
	if (IS_ERR(segs))
		goto out;

	/* All that is left is update SCTP CRC if necessary */
	if (!(features & NETIF_F_SCTP_CRC)) {
		for (skb = segs; skb; skb = skb->next) {
			if (skb->ip_summed == CHECKSUM_PARTIAL) {
				sh = sctp_hdr(skb);
				sh->checksum = sctp_gso_make_checksum(skb);
			}
		}
	}

out:
	return segs;
}

static const struct net_offload sctp_offload = {
	.callbacks = {
		.gso_segment = sctp_gso_segment,
	},
};

static const struct net_offload sctp6_offload = {
	.callbacks = {
		.gso_segment = sctp_gso_segment,
	},
};

int __init sctp_offload_init(void)
{
	int ret;

	ret = inet_add_offload(&sctp_offload, IPPROTO_SCTP);
	if (ret)
		goto out;

	ret = inet6_add_offload(&sctp6_offload, IPPROTO_SCTP);
	if (ret)
		goto ipv4;

	return ret;

ipv4:
	inet_del_offload(&sctp_offload, IPPROTO_SCTP);
out:
	return ret;
}
40b5f1d93e968ee3'>root</a>/<a href='/cgit.cgi/linux/net-next.git/commit/net?id=6e978b22efa1db9f6e71b24440b5f1d93e968ee3'>net</a>/<a href='/cgit.cgi/linux/net-next.git/commit/net/ncsi?id=6e978b22efa1db9f6e71b24440b5f1d93e968ee3'>ncsi</a>/<a href='/cgit.cgi/linux/net-next.git/commit/net/ncsi/ncsi-manage.c?id=6e978b22efa1db9f6e71b24440b5f1d93e968ee3'>ncsi-manage.c</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='id' value='6e978b22efa1db9f6e71b24440b5f1d93e968ee3'/><table><tr><td colspan='2'/></tr><tr><td class='label'>context:</td><td class='ctrl'><select name='context' onchange='this.form.submit();'><option value='1'>1</option><option value='2'>2</option><option value='3' selected='selected'>3</option><option value='4'>4</option><option value='5'>5</option><option value='6'>6</option><option value='7'>7</option><option value='8'>8</option><option value='9'>9</option><option value='10'>10</option><option value='15'>15</option><option value='20'>20</option><option value='25'>25</option><option value='30'>30</option><option value='35'>35</option><option value='40'>40</option></select></td></tr><tr><td class='label'>space:</td><td class='ctrl'><select name='ignorews' onchange='this.form.submit();'><option value='0' selected='selected'>include</option><option value='1'>ignore</option></select></td></tr><tr><td class='label'>mode:</td><td class='ctrl'><select name='dt' onchange='this.form.submit();'><option value='0' selected='selected'>unified</option><option value='1'>ssdiff</option><option value='2'>stat only</option></select></td></tr><tr><td/><td class='ctrl'><noscript><input type='submit' value='reload'/></noscript></td></tr></table></form></div><table summary='commit info' class='commit-info'>
<tr><th>author</th><td>Srinivas Pandruvada &lt;srinivas.pandruvada@linux.intel.com&gt;</td><td class='right'>2017-02-03 14:18:39 -0800</td></tr>
<tr><th>committer</th><td>Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;</td><td class='right'>2017-02-04 00:11:08 +0100</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/ncsi/ncsi-manage.c?id=6e978b22efa1db9f6e71b24440b5f1d93e968ee3'>6e978b22efa1db9f6e71b24440b5f1d93e968ee3</a> (<a href='/cgit.cgi/linux/net-next.git/patch/net/ncsi/ncsi-manage.c?id=6e978b22efa1db9f6e71b24440b5f1d93e968ee3'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=6e978b22efa1db9f6e71b24440b5f1d93e968ee3'>c666f7a26b860674848949e39a610222b0723f89</a> /<a href='/cgit.cgi/linux/net-next.git/tree/net/ncsi/ncsi-manage.c?id=6e978b22efa1db9f6e71b24440b5f1d93e968ee3'>net/ncsi/ncsi-manage.c</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/net/ncsi/ncsi-manage.c?id=3c223c19aea85d3dda1416c187915f4a30b04b1f'>3c223c19aea85d3dda1416c187915f4a30b04b1f</a> (<a href='/cgit.cgi/linux/net-next.git/diff/net/ncsi/ncsi-manage.c?id=6e978b22efa1db9f6e71b24440b5f1d93e968ee3&amp;id2=3c223c19aea85d3dda1416c187915f4a30b04b1f'>diff</a>)</td></tr></table>
<div class='commit-subject'>cpufreq: intel_pstate: Disable energy efficiency optimization</div><div class='commit-msg'>Some Kabylake desktop processors may not reach max turbo when running in
HWP mode, even if running under sustained 100% utilization.

This occurs when the HWP.EPP (Energy Performance Preference) is set to
"balance_power" (0x80) -- the default on most systems.

It occurs because the platform BIOS may erroneously enable an
energy-efficiency setting -- MSR_IA32_POWER_CTL BIT-EE, which is not
recommended to be enabled on this SKU.

On the failing systems, this BIOS issue was not discovered when the
desktop motherboard was tested with Windows, because the BIOS also
neglects to provide the ACPI/CPPC table, that Windows requires to enable
HWP, and so Windows runs in legacy P-state mode, where this setting has
no effect.

Linux' intel_pstate driver does not require ACPI/CPPC to enable HWP, and
so it runs in HWP mode, exposing this incorrect BIOS configuration.

There are several ways to address this problem.

First, Linux can also run in legacy P-state mode on this system.
As intel_pstate is how Linux enables HWP, booting with
"intel_pstate=disable"
will run in acpi-cpufreq/ondemand legacy p-state mode.

Or second, the "performance" governor can be used with intel_pstate,
which will modify HWP.EPP to 0.

Or third, starting in 4.10, the
/sys/devices/system/cpu/cpufreq/policy*/energy_performance_preference
attribute in can be updated from "balance_power" to "performance".

Or fourth, apply this patch, which fixes the erroneous setting of
MSR_IA32_POWER_CTL BIT_EE on this model, allowing the default
configuration to function as designed.

Signed-off-by: Srinivas Pandruvada &lt;srinivas.pandruvada@linux.intel.com&gt;
Reviewed-by: Len Brown &lt;len.brown@intel.com&gt;
Cc: 4.6+ &lt;stable@vger.kernel.org&gt; # 4.6+
Signed-off-by: Rafael J. Wysocki &lt;rafael.j.wysocki@intel.com&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=6e978b22efa1db9f6e71b24440b5f1d93e968ee3'>Diffstat</a> (limited to 'net/ncsi/ncsi-manage.c')</div><table summary='diffstat' class='diffstat'>