forked from Minki/linux
9da3489210
Traditionally it has been drmgr's responsibilty to update the device tree through the /proc/ppc64/ofdt interface after a suspend/resume operation. This patchset however has modified suspend/resume ops to preform an update entirely in the kernel during the resume. Therefore, a mechanism is required to expose that information to drmgr. This patch adds a show function to the "hibernate" attribute that returns 1 if the kernel performs a device tree update after the resume and 0 otherwise. This allows newer versions of drmgr to avoid doing a second unnecessary device tree update. Signed-off-by: Tyrel Datwyler <tyreld@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
285 lines
6.6 KiB
C
285 lines
6.6 KiB
C
/*
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* Copyright (C) 2010 Brian King IBM Corporation
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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#include <linux/cpu.h>
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#include <linux/delay.h>
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#include <linux/suspend.h>
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#include <linux/stat.h>
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#include <asm/firmware.h>
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#include <asm/hvcall.h>
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#include <asm/machdep.h>
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#include <asm/mmu.h>
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#include <asm/rtas.h>
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#include <asm/topology.h>
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#include "../../kernel/cacheinfo.h"
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static u64 stream_id;
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static struct device suspend_dev;
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static DECLARE_COMPLETION(suspend_work);
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static struct rtas_suspend_me_data suspend_data;
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static atomic_t suspending;
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/**
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* pseries_suspend_begin - First phase of hibernation
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*
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* Check to ensure we are in a valid state to hibernate
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*
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* Return value:
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* 0 on success / other on failure
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**/
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static int pseries_suspend_begin(suspend_state_t state)
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{
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long vasi_state, rc;
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unsigned long retbuf[PLPAR_HCALL_BUFSIZE];
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/* Make sure the state is valid */
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rc = plpar_hcall(H_VASI_STATE, retbuf, stream_id);
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vasi_state = retbuf[0];
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if (rc) {
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pr_err("pseries_suspend_begin: vasi_state returned %ld\n",rc);
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return rc;
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} else if (vasi_state == H_VASI_ENABLED) {
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return -EAGAIN;
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} else if (vasi_state != H_VASI_SUSPENDING) {
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pr_err("pseries_suspend_begin: vasi_state returned state %ld\n",
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vasi_state);
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return -EIO;
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}
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return 0;
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}
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/**
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* pseries_suspend_cpu - Suspend a single CPU
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*
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* Makes the H_JOIN call to suspend the CPU
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*
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**/
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static int pseries_suspend_cpu(void)
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{
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if (atomic_read(&suspending))
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return rtas_suspend_cpu(&suspend_data);
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return 0;
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}
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/**
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* pseries_suspend_enable_irqs
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*
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* Post suspend configuration updates
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*
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**/
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static void pseries_suspend_enable_irqs(void)
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{
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/*
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* Update configuration which can be modified based on device tree
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* changes during resume.
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*/
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cacheinfo_cpu_offline(smp_processor_id());
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post_mobility_fixup();
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cacheinfo_cpu_online(smp_processor_id());
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}
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/**
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* pseries_suspend_enter - Final phase of hibernation
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*
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* Return value:
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* 0 on success / other on failure
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**/
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static int pseries_suspend_enter(suspend_state_t state)
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{
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int rc = rtas_suspend_last_cpu(&suspend_data);
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atomic_set(&suspending, 0);
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atomic_set(&suspend_data.done, 1);
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return rc;
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}
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/**
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* pseries_prepare_late - Prepare to suspend all other CPUs
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*
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* Return value:
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* 0 on success / other on failure
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**/
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static int pseries_prepare_late(void)
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{
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atomic_set(&suspending, 1);
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atomic_set(&suspend_data.working, 0);
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atomic_set(&suspend_data.done, 0);
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atomic_set(&suspend_data.error, 0);
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suspend_data.complete = &suspend_work;
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reinit_completion(&suspend_work);
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return 0;
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}
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/**
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* store_hibernate - Initiate partition hibernation
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* @dev: subsys root device
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* @attr: device attribute struct
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* @buf: buffer
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* @count: buffer size
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*
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* Write the stream ID received from the HMC to this file
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* to trigger hibernating the partition
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*
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* Return value:
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* number of bytes printed to buffer / other on failure
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**/
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static ssize_t store_hibernate(struct device *dev,
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struct device_attribute *attr,
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const char *buf, size_t count)
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{
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cpumask_var_t offline_mask;
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int rc;
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if (!capable(CAP_SYS_ADMIN))
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return -EPERM;
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if (!alloc_cpumask_var(&offline_mask, GFP_TEMPORARY))
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return -ENOMEM;
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stream_id = simple_strtoul(buf, NULL, 16);
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do {
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rc = pseries_suspend_begin(PM_SUSPEND_MEM);
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if (rc == -EAGAIN)
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ssleep(1);
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} while (rc == -EAGAIN);
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if (!rc) {
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/* All present CPUs must be online */
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cpumask_andnot(offline_mask, cpu_present_mask,
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cpu_online_mask);
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rc = rtas_online_cpus_mask(offline_mask);
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if (rc) {
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pr_err("%s: Could not bring present CPUs online.\n",
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__func__);
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goto out;
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}
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stop_topology_update();
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rc = pm_suspend(PM_SUSPEND_MEM);
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start_topology_update();
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/* Take down CPUs not online prior to suspend */
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if (!rtas_offline_cpus_mask(offline_mask))
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pr_warn("%s: Could not restore CPUs to offline "
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"state.\n", __func__);
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}
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stream_id = 0;
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if (!rc)
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rc = count;
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out:
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free_cpumask_var(offline_mask);
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return rc;
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}
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#define USER_DT_UPDATE 0
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#define KERN_DT_UPDATE 1
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/**
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* show_hibernate - Report device tree update responsibilty
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* @dev: subsys root device
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* @attr: device attribute struct
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* @buf: buffer
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*
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* Report whether a device tree update is performed by the kernel after a
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* resume, or if drmgr must coordinate the update from user space.
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*
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* Return value:
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* 0 if drmgr is to initiate update, and 1 otherwise
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**/
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static ssize_t show_hibernate(struct device *dev,
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struct device_attribute *attr,
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char *buf)
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{
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return sprintf(buf, "%d\n", KERN_DT_UPDATE);
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}
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static DEVICE_ATTR(hibernate, S_IWUSR | S_IRUGO,
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show_hibernate, store_hibernate);
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static struct bus_type suspend_subsys = {
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.name = "power",
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.dev_name = "power",
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};
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static const struct platform_suspend_ops pseries_suspend_ops = {
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.valid = suspend_valid_only_mem,
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.begin = pseries_suspend_begin,
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.prepare_late = pseries_prepare_late,
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.enter = pseries_suspend_enter,
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};
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/**
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* pseries_suspend_sysfs_register - Register with sysfs
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*
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* Return value:
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* 0 on success / other on failure
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**/
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static int pseries_suspend_sysfs_register(struct device *dev)
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{
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int rc;
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if ((rc = subsys_system_register(&suspend_subsys, NULL)))
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return rc;
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dev->id = 0;
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dev->bus = &suspend_subsys;
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if ((rc = device_create_file(suspend_subsys.dev_root, &dev_attr_hibernate)))
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goto subsys_unregister;
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return 0;
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subsys_unregister:
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bus_unregister(&suspend_subsys);
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return rc;
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}
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/**
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* pseries_suspend_init - initcall for pSeries suspend
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*
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* Return value:
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* 0 on success / other on failure
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**/
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static int __init pseries_suspend_init(void)
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{
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int rc;
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if (!machine_is(pseries) || !firmware_has_feature(FW_FEATURE_LPAR))
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return 0;
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suspend_data.token = rtas_token("ibm,suspend-me");
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if (suspend_data.token == RTAS_UNKNOWN_SERVICE)
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return 0;
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if ((rc = pseries_suspend_sysfs_register(&suspend_dev)))
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return rc;
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ppc_md.suspend_disable_cpu = pseries_suspend_cpu;
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ppc_md.suspend_enable_irqs = pseries_suspend_enable_irqs;
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suspend_set_ops(&pseries_suspend_ops);
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return 0;
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}
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__initcall(pseries_suspend_init);
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