/*
 * w1_ds2406.c - w1 family 12 (DS2406) driver
 * based on w1_ds2413.c by Mariusz Bialonczyk <manio@skyboo.net>
 *
 * Copyright (c) 2014 Scott Alfter <scott@alfter.us>
 *
 * This source code is licensed under the GNU General Public License,
 * Version 2. See the file COPYING for more details.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/device.h>
#include <linux/types.h>
#include <linux/delay.h>
#include <linux/slab.h>
#include <linux/crc16.h>

#include "../w1.h"
#include "../w1_int.h"
#include "../w1_family.h"

MODULE_LICENSE("GPL");
MODULE_AUTHOR("Scott Alfter <scott@alfter.us>");
MODULE_DESCRIPTION("w1 family 12 driver for DS2406 2 Pin IO");

#define W1_F12_FUNC_READ_STATUS		   0xAA
#define W1_F12_FUNC_WRITE_STATUS	   0x55

static ssize_t w1_f12_read_state(
	struct file *filp, struct kobject *kobj,
	struct bin_attribute *bin_attr,
	char *buf, loff_t off, size_t count)
{
	u8 w1_buf[6]={W1_F12_FUNC_READ_STATUS, 7, 0, 0, 0, 0};
	struct w1_slave *sl = kobj_to_w1_slave(kobj);
	u16 crc=0;
	int i;
	ssize_t rtnval=1;

	if (off != 0)
		return 0;
	if (!buf)
		return -EINVAL;

	mutex_lock(&sl->master->bus_mutex);

	if (w1_reset_select_slave(sl)) {
		mutex_unlock(&sl->master->bus_mutex);
		return -EIO;
	}

	w1_write_block(sl->master, w1_buf, 3);
	w1_read_block(sl->master, w1_buf+3, 3);
	for (i=0; i<6; i++)
		crc=crc16_byte(crc, w1_buf[i]);
	if (crc==0xb001) /* good read? */
		*buf=((w1_buf[3]>>5)&3)|0x30;
	else
		rtnval=-EIO;

	mutex_unlock(&sl->master->bus_mutex);

	return rtnval;
}

static ssize_t w1_f12_write_output(
	struct file *filp, struct kobject *kobj,
	struct bin_attribute *bin_attr,
	char *buf, loff_t off, size_t count)
{
	struct w1_slave *sl = kobj_to_w1_slave(kobj);
	u8 w1_buf[6]={W1_F12_FUNC_WRITE_STATUS, 7, 0, 0, 0, 0};
	u16 crc=0;
	int i;
	ssize_t rtnval=1;

	if (count != 1 || off != 0)
		return -EFAULT;

	mutex_lock(&sl->master->bus_mutex);

	if (w1_reset_select_slave(sl)) {
		mutex_unlock(&sl->master->bus_mutex);
		return -EIO;
	}

	w1_buf[3] = (((*buf)&3)<<5)|0x1F;
	w1_write_block(sl->master, w1_buf, 4);
	w1_read_block(sl->master, w1_buf+4, 2);
	for (i=0; i<6; i++)
		crc=crc16_byte(crc, w1_buf[i]);
	if (crc==0xb001) /* good read? */
		w1_write_8(sl->master, 0xFF);
	else
		rtnval=-EIO;

	mutex_unlock(&sl->master->bus_mutex);
	return rtnval;
}

#define NB_SYSFS_BIN_FILES 2
static struct bin_attribute w1_f12_sysfs_bin_files[NB_SYSFS_BIN_FILES] = {
	{
		.attr = {
			.name = "state",
			.mode = S_IRUGO,
		},
		.size = 1,
		.read = w1_f12_read_state,
	},
	{
		.attr = {
			.name = "output",
			.mode = S_IRUGO | S_IWUSR | S_IWGRP,
		},
		.size = 1,
		.write = w1_f12_write_output,
	}
};

static int w1_f12_add_slave(struct w1_slave *sl)
{
	int err = 0;
	int i;

	for (i = 0; i < NB_SYSFS_BIN_FILES && !err; ++i)
		err = sysfs_create_bin_file(
			&sl->dev.kobj,
			&(w1_f12_sysfs_bin_files[i]));
	if (err)
		while (--i >= 0)
			sysfs_remove_bin_file(&sl->dev.kobj,
				&(w1_f12_sysfs_bin_files[i]));
	return err;
}

static void w1_f12_remove_slave(struct w1_slave *sl)
{
	int i;
	for (i = NB_SYSFS_BIN_FILES - 1; i >= 0; --i)
		sysfs_remove_bin_file(&sl->dev.kobj,
			&(w1_f12_sysfs_bin_files[i]));
}

static struct w1_family_ops w1_f12_fops = {
	.add_slave      = w1_f12_add_slave,
	.remove_slave   = w1_f12_remove_slave,
};

static struct w1_family w1_family_12 = {
	.fid = W1_FAMILY_DS2406,
	.fops = &w1_f12_fops,
};
module_w1_family(w1_family_12);
inux/net-next.git/commit/tools/virtio/virtio-trace?h=nds-private-remove&amp;id=bf29bddf0417a4783da3b24e8c9e017ac649326f'>virtio-trace</a>/<a href='/cgit.cgi/linux/net-next.git/commit/tools/virtio/virtio-trace/trace-agent.h?h=nds-private-remove&amp;id=bf29bddf0417a4783da3b24e8c9e017ac649326f'>trace-agent.h</a></div><div class='content'><div class='cgit-panel'><b>diff options</b><form method='get'><input type='hidden' name='h' value='nds-private-remove'/><input type='hidden' name='id' value='bf29bddf0417a4783da3b24e8c9e017ac649326f'/><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>Jiri Kosina &lt;jkosina@suse.cz&gt;</td><td class='right'>2017-01-27 22:25:52 +0000</td></tr>
<tr><th>committer</th><td>Ingo Molnar &lt;mingo@kernel.org&gt;</td><td class='right'>2017-01-28 09:18:56 +0100</td></tr>
<tr><th>commit</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/tools/virtio/virtio-trace/trace-agent.h?h=nds-private-remove&amp;id=bf29bddf0417a4783da3b24e8c9e017ac649326f'>bf29bddf0417a4783da3b24e8c9e017ac649326f</a> (<a href='/cgit.cgi/linux/net-next.git/patch/tools/virtio/virtio-trace/trace-agent.h?id=bf29bddf0417a4783da3b24e8c9e017ac649326f'>patch</a>)</td></tr>
<tr><th>tree</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/tree/?h=nds-private-remove&amp;id=bf29bddf0417a4783da3b24e8c9e017ac649326f'>54a05a4883b73f80e4e1d8c4b15750aa01c39932</a> /<a href='/cgit.cgi/linux/net-next.git/tree/tools/virtio/virtio-trace/trace-agent.h?h=nds-private-remove&amp;id=bf29bddf0417a4783da3b24e8c9e017ac649326f'>tools/virtio/virtio-trace/trace-agent.h</a></td></tr>
<tr><th>parent</th><td colspan='2' class='oid'><a href='/cgit.cgi/linux/net-next.git/commit/tools/virtio/virtio-trace/trace-agent.h?h=nds-private-remove&amp;id=883af14e67e8b8702b5560aa64c888c0cd0bd66c'>883af14e67e8b8702b5560aa64c888c0cd0bd66c</a> (<a href='/cgit.cgi/linux/net-next.git/diff/tools/virtio/virtio-trace/trace-agent.h?h=nds-private-remove&amp;id=bf29bddf0417a4783da3b24e8c9e017ac649326f&amp;id2=883af14e67e8b8702b5560aa64c888c0cd0bd66c'>diff</a>)</td></tr></table>
<div class='commit-subject'>x86/efi: Always map the first physical page into the EFI pagetables</div><div class='commit-msg'>Commit:

  129766708 ("x86/efi: Only map RAM into EFI page tables if in mixed-mode")

stopped creating 1:1 mappings for all RAM, when running in native 64-bit mode.

It turns out though that there are 64-bit EFI implementations in the wild
(this particular problem has been reported on a Lenovo Yoga 710-11IKB),
which still make use of the first physical page for their own private use,
even though they explicitly mark it EFI_CONVENTIONAL_MEMORY in the memory
map.

In case there is no mapping for this particular frame in the EFI pagetables,
as soon as firmware tries to make use of it, a triple fault occurs and the
system reboots (in case of the Yoga 710-11IKB this is very early during bootup).

Fix that by always mapping the first page of physical memory into the EFI
pagetables. We're free to hand this page to the BIOS, as trim_bios_range()
will reserve the first page and isolate it away from memory allocators anyway.

Note that just reverting 129766708 alone is not enough on v4.9-rc1+ to fix the
regression on affected hardware, as this commit:

   ab72a27da ("x86/efi: Consolidate region mapping logic")

later made the first physical frame not to be mapped anyway.

Reported-by: Hanka Pavlikova &lt;hanka@ucw.cz&gt;
Signed-off-by: Jiri Kosina &lt;jkosina@suse.cz&gt;
Signed-off-by: Matt Fleming &lt;matt@codeblueprint.co.uk&gt;
Cc: Ard Biesheuvel &lt;ard.biesheuvel@linaro.org&gt;
Cc: Borislav Petkov &lt;bp@alien8.de&gt;
Cc: Borislav Petkov &lt;bp@suse.de&gt;
Cc: Laura Abbott &lt;labbott@redhat.com&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Cc: Peter Zijlstra &lt;peterz@infradead.org&gt;
Cc: Thomas Gleixner &lt;tglx@linutronix.de&gt;
Cc: Vojtech Pavlik &lt;vojtech@ucw.cz&gt;
Cc: Waiman Long &lt;waiman.long@hpe.com&gt;
Cc: linux-efi@vger.kernel.org
Cc: stable@kernel.org # v4.8+
Fixes: 129766708 ("x86/efi: Only map RAM into EFI page tables if in mixed-mode")
Link: http://lkml.kernel.org/r/20170127222552.22336-1-matt@codeblueprint.co.uk
[ Tidied up the changelog and the comment. ]
Signed-off-by: Ingo Molnar &lt;mingo@kernel.org&gt;
</div><div class='diffstat-header'><a href='/cgit.cgi/linux/net-next.git/diff/?h=nds-private-remove&amp;id=bf29bddf0417a4783da3b24e8c9e017ac649326f'>Diffstat</a> (limited to 'tools/virtio/virtio-trace/trace-agent.h')</div><table summary='diffstat' class='diffstat'>