mirror of
https://github.com/torvalds/linux.git
synced 2024-11-17 17:41:44 +00:00
21e6ba3f0e
As explained during the 2018 LSF/MM session about increasing SCSI disk
probing concurrency, the problems with the current probing approach are as
follows:
- The driver core is unaware of asynchronous SCSI LUN probing.
wait_for_device_probe() waits for all asynchronous probes except
asynchronous SCSI disk probes.
- There is unnecessary serialization between sd_probe() and sd_remove().
This can lead to a deadlock.
Hence this patch that modifies the sd driver such that it uses the driver
core framework for asynchronous probing. The async domains and
get_device()/put_device() pairs that became superfluous due to this change
are removed.
This patch does not affect the time needed for loading the scsi_debug
kernel module with parameters delay=0 and max_luns=256.
This patch depends on commit ef0ff68351 ("driver core: Probe devices
asynchronously instead of the driver") that went upstream in kernel version
v5.1-rc1.
Cc: Lee Duncan <lduncan@suse.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Johannes Thumshirn <jthumshirn@suse.de>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
342 lines
7.5 KiB
C
342 lines
7.5 KiB
C
/*
|
|
* scsi_pm.c Copyright (C) 2010 Alan Stern
|
|
*
|
|
* SCSI dynamic Power Management
|
|
* Initial version: Alan Stern <stern@rowland.harvard.edu>
|
|
*/
|
|
|
|
#include <linux/pm_runtime.h>
|
|
#include <linux/export.h>
|
|
#include <linux/async.h>
|
|
#include <linux/blk-pm.h>
|
|
|
|
#include <scsi/scsi.h>
|
|
#include <scsi/scsi_device.h>
|
|
#include <scsi/scsi_driver.h>
|
|
#include <scsi/scsi_host.h>
|
|
|
|
#include "scsi_priv.h"
|
|
|
|
#ifdef CONFIG_PM_SLEEP
|
|
|
|
static int do_scsi_suspend(struct device *dev, const struct dev_pm_ops *pm)
|
|
{
|
|
return pm && pm->suspend ? pm->suspend(dev) : 0;
|
|
}
|
|
|
|
static int do_scsi_freeze(struct device *dev, const struct dev_pm_ops *pm)
|
|
{
|
|
return pm && pm->freeze ? pm->freeze(dev) : 0;
|
|
}
|
|
|
|
static int do_scsi_poweroff(struct device *dev, const struct dev_pm_ops *pm)
|
|
{
|
|
return pm && pm->poweroff ? pm->poweroff(dev) : 0;
|
|
}
|
|
|
|
static int do_scsi_resume(struct device *dev, const struct dev_pm_ops *pm)
|
|
{
|
|
return pm && pm->resume ? pm->resume(dev) : 0;
|
|
}
|
|
|
|
static int do_scsi_thaw(struct device *dev, const struct dev_pm_ops *pm)
|
|
{
|
|
return pm && pm->thaw ? pm->thaw(dev) : 0;
|
|
}
|
|
|
|
static int do_scsi_restore(struct device *dev, const struct dev_pm_ops *pm)
|
|
{
|
|
return pm && pm->restore ? pm->restore(dev) : 0;
|
|
}
|
|
|
|
static int scsi_dev_type_suspend(struct device *dev,
|
|
int (*cb)(struct device *, const struct dev_pm_ops *))
|
|
{
|
|
const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
|
|
int err;
|
|
|
|
err = scsi_device_quiesce(to_scsi_device(dev));
|
|
if (err == 0) {
|
|
err = cb(dev, pm);
|
|
if (err)
|
|
scsi_device_resume(to_scsi_device(dev));
|
|
}
|
|
dev_dbg(dev, "scsi suspend: %d\n", err);
|
|
return err;
|
|
}
|
|
|
|
static int scsi_dev_type_resume(struct device *dev,
|
|
int (*cb)(struct device *, const struct dev_pm_ops *))
|
|
{
|
|
const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
|
|
int err = 0;
|
|
|
|
err = cb(dev, pm);
|
|
scsi_device_resume(to_scsi_device(dev));
|
|
dev_dbg(dev, "scsi resume: %d\n", err);
|
|
|
|
if (err == 0) {
|
|
pm_runtime_disable(dev);
|
|
err = pm_runtime_set_active(dev);
|
|
pm_runtime_enable(dev);
|
|
|
|
/*
|
|
* Forcibly set runtime PM status of request queue to "active"
|
|
* to make sure we can again get requests from the queue
|
|
* (see also blk_pm_peek_request()).
|
|
*
|
|
* The resume hook will correct runtime PM status of the disk.
|
|
*/
|
|
if (!err && scsi_is_sdev_device(dev)) {
|
|
struct scsi_device *sdev = to_scsi_device(dev);
|
|
|
|
if (sdev->request_queue->dev)
|
|
blk_set_runtime_active(sdev->request_queue);
|
|
}
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
static int
|
|
scsi_bus_suspend_common(struct device *dev,
|
|
int (*cb)(struct device *, const struct dev_pm_ops *))
|
|
{
|
|
int err = 0;
|
|
|
|
if (scsi_is_sdev_device(dev)) {
|
|
/*
|
|
* All the high-level SCSI drivers that implement runtime
|
|
* PM treat runtime suspend, system suspend, and system
|
|
* hibernate nearly identically. In all cases the requirements
|
|
* for runtime suspension are stricter.
|
|
*/
|
|
if (pm_runtime_suspended(dev))
|
|
return 0;
|
|
|
|
err = scsi_dev_type_suspend(dev, cb);
|
|
}
|
|
|
|
return err;
|
|
}
|
|
|
|
static void async_sdev_resume(void *dev, async_cookie_t cookie)
|
|
{
|
|
scsi_dev_type_resume(dev, do_scsi_resume);
|
|
}
|
|
|
|
static void async_sdev_thaw(void *dev, async_cookie_t cookie)
|
|
{
|
|
scsi_dev_type_resume(dev, do_scsi_thaw);
|
|
}
|
|
|
|
static void async_sdev_restore(void *dev, async_cookie_t cookie)
|
|
{
|
|
scsi_dev_type_resume(dev, do_scsi_restore);
|
|
}
|
|
|
|
static int scsi_bus_resume_common(struct device *dev,
|
|
int (*cb)(struct device *, const struct dev_pm_ops *))
|
|
{
|
|
async_func_t fn;
|
|
|
|
if (!scsi_is_sdev_device(dev))
|
|
fn = NULL;
|
|
else if (cb == do_scsi_resume)
|
|
fn = async_sdev_resume;
|
|
else if (cb == do_scsi_thaw)
|
|
fn = async_sdev_thaw;
|
|
else if (cb == do_scsi_restore)
|
|
fn = async_sdev_restore;
|
|
else
|
|
fn = NULL;
|
|
|
|
if (!fn) {
|
|
pm_runtime_disable(dev);
|
|
pm_runtime_set_active(dev);
|
|
pm_runtime_enable(dev);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int scsi_bus_prepare(struct device *dev)
|
|
{
|
|
if (scsi_is_host_device(dev)) {
|
|
/* Wait until async scanning is finished */
|
|
scsi_complete_async_scans();
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int scsi_bus_suspend(struct device *dev)
|
|
{
|
|
return scsi_bus_suspend_common(dev, do_scsi_suspend);
|
|
}
|
|
|
|
static int scsi_bus_resume(struct device *dev)
|
|
{
|
|
return scsi_bus_resume_common(dev, do_scsi_resume);
|
|
}
|
|
|
|
static int scsi_bus_freeze(struct device *dev)
|
|
{
|
|
return scsi_bus_suspend_common(dev, do_scsi_freeze);
|
|
}
|
|
|
|
static int scsi_bus_thaw(struct device *dev)
|
|
{
|
|
return scsi_bus_resume_common(dev, do_scsi_thaw);
|
|
}
|
|
|
|
static int scsi_bus_poweroff(struct device *dev)
|
|
{
|
|
return scsi_bus_suspend_common(dev, do_scsi_poweroff);
|
|
}
|
|
|
|
static int scsi_bus_restore(struct device *dev)
|
|
{
|
|
return scsi_bus_resume_common(dev, do_scsi_restore);
|
|
}
|
|
|
|
#else /* CONFIG_PM_SLEEP */
|
|
|
|
#define scsi_bus_prepare NULL
|
|
#define scsi_bus_suspend NULL
|
|
#define scsi_bus_resume NULL
|
|
#define scsi_bus_freeze NULL
|
|
#define scsi_bus_thaw NULL
|
|
#define scsi_bus_poweroff NULL
|
|
#define scsi_bus_restore NULL
|
|
|
|
#endif /* CONFIG_PM_SLEEP */
|
|
|
|
static int sdev_runtime_suspend(struct device *dev)
|
|
{
|
|
const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
|
|
struct scsi_device *sdev = to_scsi_device(dev);
|
|
int err = 0;
|
|
|
|
err = blk_pre_runtime_suspend(sdev->request_queue);
|
|
if (err)
|
|
return err;
|
|
if (pm && pm->runtime_suspend)
|
|
err = pm->runtime_suspend(dev);
|
|
blk_post_runtime_suspend(sdev->request_queue, err);
|
|
|
|
return err;
|
|
}
|
|
|
|
static int scsi_runtime_suspend(struct device *dev)
|
|
{
|
|
int err = 0;
|
|
|
|
dev_dbg(dev, "scsi_runtime_suspend\n");
|
|
if (scsi_is_sdev_device(dev))
|
|
err = sdev_runtime_suspend(dev);
|
|
|
|
/* Insert hooks here for targets, hosts, and transport classes */
|
|
|
|
return err;
|
|
}
|
|
|
|
static int sdev_runtime_resume(struct device *dev)
|
|
{
|
|
struct scsi_device *sdev = to_scsi_device(dev);
|
|
const struct dev_pm_ops *pm = dev->driver ? dev->driver->pm : NULL;
|
|
int err = 0;
|
|
|
|
blk_pre_runtime_resume(sdev->request_queue);
|
|
if (pm && pm->runtime_resume)
|
|
err = pm->runtime_resume(dev);
|
|
blk_post_runtime_resume(sdev->request_queue, err);
|
|
|
|
return err;
|
|
}
|
|
|
|
static int scsi_runtime_resume(struct device *dev)
|
|
{
|
|
int err = 0;
|
|
|
|
dev_dbg(dev, "scsi_runtime_resume\n");
|
|
if (scsi_is_sdev_device(dev))
|
|
err = sdev_runtime_resume(dev);
|
|
|
|
/* Insert hooks here for targets, hosts, and transport classes */
|
|
|
|
return err;
|
|
}
|
|
|
|
static int scsi_runtime_idle(struct device *dev)
|
|
{
|
|
dev_dbg(dev, "scsi_runtime_idle\n");
|
|
|
|
/* Insert hooks here for targets, hosts, and transport classes */
|
|
|
|
if (scsi_is_sdev_device(dev)) {
|
|
pm_runtime_mark_last_busy(dev);
|
|
pm_runtime_autosuspend(dev);
|
|
return -EBUSY;
|
|
}
|
|
|
|
return 0;
|
|
}
|
|
|
|
int scsi_autopm_get_device(struct scsi_device *sdev)
|
|
{
|
|
int err;
|
|
|
|
err = pm_runtime_get_sync(&sdev->sdev_gendev);
|
|
if (err < 0 && err !=-EACCES)
|
|
pm_runtime_put_sync(&sdev->sdev_gendev);
|
|
else
|
|
err = 0;
|
|
return err;
|
|
}
|
|
EXPORT_SYMBOL_GPL(scsi_autopm_get_device);
|
|
|
|
void scsi_autopm_put_device(struct scsi_device *sdev)
|
|
{
|
|
pm_runtime_put_sync(&sdev->sdev_gendev);
|
|
}
|
|
EXPORT_SYMBOL_GPL(scsi_autopm_put_device);
|
|
|
|
void scsi_autopm_get_target(struct scsi_target *starget)
|
|
{
|
|
pm_runtime_get_sync(&starget->dev);
|
|
}
|
|
|
|
void scsi_autopm_put_target(struct scsi_target *starget)
|
|
{
|
|
pm_runtime_put_sync(&starget->dev);
|
|
}
|
|
|
|
int scsi_autopm_get_host(struct Scsi_Host *shost)
|
|
{
|
|
int err;
|
|
|
|
err = pm_runtime_get_sync(&shost->shost_gendev);
|
|
if (err < 0 && err !=-EACCES)
|
|
pm_runtime_put_sync(&shost->shost_gendev);
|
|
else
|
|
err = 0;
|
|
return err;
|
|
}
|
|
|
|
void scsi_autopm_put_host(struct Scsi_Host *shost)
|
|
{
|
|
pm_runtime_put_sync(&shost->shost_gendev);
|
|
}
|
|
|
|
const struct dev_pm_ops scsi_bus_pm_ops = {
|
|
.prepare = scsi_bus_prepare,
|
|
.suspend = scsi_bus_suspend,
|
|
.resume = scsi_bus_resume,
|
|
.freeze = scsi_bus_freeze,
|
|
.thaw = scsi_bus_thaw,
|
|
.poweroff = scsi_bus_poweroff,
|
|
.restore = scsi_bus_restore,
|
|
.runtime_suspend = scsi_runtime_suspend,
|
|
.runtime_resume = scsi_runtime_resume,
|
|
.runtime_idle = scsi_runtime_idle,
|
|
};
|