/* Copyright (c) 2013-2015 PLUMgrid, http://plumgrid.com
 * Copyright (c) 2015 BMW Car IT GmbH
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of version 2 of the GNU General Public
 * License as published by the Free Software Foundation.
 */
#include <linux/version.h>
#include <linux/ptrace.h>
#include <uapi/linux/bpf.h>
#include "bpf_helpers.h"

#define MAX_ENTRIES	20
#define MAX_CPU		4

/* We need to stick to static allocated memory (an array instead of
 * hash table) because managing dynamic memory from the
 * trace_preempt_[on|off] tracepoints hooks is not supported.
 */

struct bpf_map_def SEC("maps") my_map = {
	.type = BPF_MAP_TYPE_ARRAY,
	.key_size = sizeof(int),
	.value_size = sizeof(u64),
	.max_entries = MAX_CPU,
};

SEC("kprobe/trace_preempt_off")
int bpf_prog1(struct pt_regs *ctx)
{
	int cpu = bpf_get_smp_processor_id();
	u64 *ts = bpf_map_lookup_elem(&my_map, &cpu);

	if (ts)
		*ts = bpf_ktime_get_ns();

	return 0;
}

static unsigned int log2(unsigned int v)
{
	unsigned int r;
	unsigned int shift;

	r = (v > 0xFFFF) << 4; v >>= r;
	shift = (v > 0xFF) << 3; v >>= shift; r |= shift;
	shift = (v > 0xF) << 2; v >>= shift; r |= shift;
	shift = (v > 0x3) << 1; v >>= shift; r |= shift;
	r |= (v >> 1);

	return r;
}

static unsigned int log2l(unsigned long v)
{
	unsigned int hi = v >> 32;

	if (hi)
		return log2(hi) + 32;
	else
		return log2(v);
}

struct bpf_map_def SEC("maps") my_lat = {
	.type = BPF_MAP_TYPE_ARRAY,
	.key_size = sizeof(int),
	.value_size = sizeof(long),
	.max_entries = MAX_CPU * MAX_ENTRIES,
};

SEC("kprobe/trace_preempt_on")
int bpf_prog2(struct pt_regs *ctx)
{
	u64 *ts, cur_ts, delta;
	int key, cpu;
	long *val;

	cpu = bpf_get_smp_processor_id();
	ts = bpf_map_lookup_elem(&my_map, &cpu);
	if (!ts)
		return 0;

	cur_ts = bpf_ktime_get_ns();
	delta = log2l(cur_ts - *ts);

	if (delta > MAX_ENTRIES - 1)
		delta = MAX_ENTRIES - 1;

	key = cpu * MAX_ENTRIES + delta;
	val = bpf_map_lookup_elem(&my_lat, &key);
	if (val)
		__sync_fetch_and_add((long *)val, 1);

	return 0;

}

char _license[] SEC("license") = "GPL";
u32 _version SEC("version") = LINUX_VERSION_CODE;
sb/renesas_usbhs/mod_host.c?id=a0a28644c1cf191e514dd64bf438e69c178b8440'>diff</a></td><td class='form'><form class='right' method='get' action='/cgit.cgi/linux/net-next.git/log/drivers/usb/renesas_usbhs/mod_host.c'>
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<option value='grep'>log msg</option>
<option value='author'>author</option>
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<option value='range'>range</option>
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<input class='txt' type='search' size='10' name='q' value=''/>
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<div class='path'>path: <a href='/cgit.cgi/linux/net-next.git/commit/?id=a0a28644c1cf191e514dd64bf438e69c178b8440'>root</a>/<a href='/cgit.cgi/linux/net-next.git/commit/drivers?id=a0a28644c1cf191e514dd64bf438e69c178b8440'>drivers</a>/<a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb?id=a0a28644c1cf191e514dd64bf438e69c178b8440'>usb</a>/<a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb/renesas_usbhs?id=a0a28644c1cf191e514dd64bf438e69c178b8440'>renesas_usbhs</a>/<a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb/renesas_usbhs/mod_host.c?id=a0a28644c1cf191e514dd64bf438e69c178b8440'>mod_host.c</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='id' value='a0a28644c1cf191e514dd64bf438e69c178b8440'/><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>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2017-02-03 16:18:51 -0800</td></tr>
<tr><th>committer</th><td>Linus Torvalds &lt;torvalds@linux-foundation.org&gt;</td><td class='right'>2017-02-03 16:18:51 -0800</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb/renesas_usbhs/mod_host.c?id=a0a28644c1cf191e514dd64bf438e69c178b8440'>a0a28644c1cf191e514dd64bf438e69c178b8440</a> (<a href='/cgit.cgi/linux/net-next.git/patch/drivers/usb/renesas_usbhs/mod_host.c?id=a0a28644c1cf191e514dd64bf438e69c178b8440'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?id=a0a28644c1cf191e514dd64bf438e69c178b8440'>4a5140d2f13692f91ca012d0eab146e9f366ce95</a> /<a href='/cgit.cgi/linux/net-next.git/tree/drivers/usb/renesas_usbhs/mod_host.c?id=a0a28644c1cf191e514dd64bf438e69c178b8440'>drivers/usb/renesas_usbhs/mod_host.c</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb/renesas_usbhs/mod_host.c?id=a49e6f584e29785f9e5eb8dd31435746818dd5c4'>a49e6f584e29785f9e5eb8dd31435746818dd5c4</a> (<a href='/cgit.cgi/linux/net-next.git/diff/drivers/usb/renesas_usbhs/mod_host.c?id=a0a28644c1cf191e514dd64bf438e69c178b8440&amp;id2=a49e6f584e29785f9e5eb8dd31435746818dd5c4'>diff</a>)</td></tr><tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/drivers/usb/renesas_usbhs/mod_host.c?id=6f3e71c0c3f2479e05682e2e563b75decab36591'>6f3e71c0c3f2479e05682e2e563b75decab36591</a> (<a href='/cgit.cgi/linux/net-next.git/diff/drivers/usb/renesas_usbhs/mod_host.c?id=a0a28644c1cf191e514dd64bf438e69c178b8440&amp;id2=6f3e71c0c3f2479e05682e2e563b75decab36591'>diff</a>)</td></tr></table>
<div class='commit-subject'>Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi</div><div class='commit-msg'>Pull SCSI fix from James Bottomley:
 "A single fix this time: a fix for a virtqueue removal bug which only
  appears to affect S390, but which results in the queue hanging forever
  thus causing the machine to fail shutdown"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: virtio_scsi: Reject commands when virtqueue is broken
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?id=a0a28644c1cf191e514dd64bf438e69c178b8440'>Diffstat</a> (limited to 'drivers/usb/renesas_usbhs/mod_host.c')</div><table summary='diffstat' class='diffstat'>