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linux/drivers/pci/pci.h
Rafael J. Wysocki c125e96f04 PM: Make it possible to avoid races between wakeup and system sleep 
One of the arguments during the suspend blockers discussion was that
the mainline kernel didn't contain any mechanisms making it possible
to avoid races between wakeup and system suspend.

Generally, there are two problems in that area.  First, if a wakeup
event occurs exactly when /sys/power/state is being written to, it
may be delivered to user space right before the freezer kicks in, so
the user space consumer of the event may not be able to process it
before the system is suspended.  Second, if a wakeup event occurs
after user space has been frozen, it is not generally guaranteed that
the ongoing transition of the system into a sleep state will be
aborted.

To address these issues introduce a new global sysfs attribute,
/sys/power/wakeup_count, associated with a running counter of wakeup
events and three helper functions, pm_stay_awake(), pm_relax(), and
pm_wakeup_event(), that may be used by kernel subsystems to control
the behavior of this attribute and to request the PM core to abort
system transitions into a sleep state already in progress.

The /sys/power/wakeup_count file may be read from or written to by
user space.  Reads will always succeed (unless interrupted by a
signal) and return the current value of the wakeup events counter.
Writes, however, will only succeed if the written number is equal to
the current value of the wakeup events counter.  If a write is
successful, it will cause the kernel to save the current value of the
wakeup events counter and to abort the subsequent system transition
into a sleep state if any wakeup events are reported after the write
has returned.

[The assumption is that before writing to /sys/power/state user space
will first read from /sys/power/wakeup_count.  Next, user space
consumers of wakeup events will have a chance to acknowledge or
veto the upcoming system transition to a sleep state.  Finally, if
the transition is allowed to proceed, /sys/power/wakeup_count will
be written to and if that succeeds, /sys/power/state will be written
to as well.  Still, if any wakeup events are reported to the PM core
by kernel subsystems after that point, the transition will be
aborted.]

Additionally, put a wakeup events counter into struct dev_pm_info and
make these per-device wakeup event counters available via sysfs,
so that it's possible to check the activity of various wakeup event
sources within the kernel.

To illustrate how subsystems can use pm_wakeup_event(), make the
low-level PCI runtime PM wakeup-handling code use it.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Acked-by: markgross <markgross@thegnar.org>
Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
2010-07-19 01:58:48 +02:00

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#ifndef DRIVERS_PCI_H
#define DRIVERS_PCI_H
#include <linux/workqueue.h>
#define PCI_CFG_SPACE_SIZE 256
#define PCI_CFG_SPACE_EXP_SIZE 4096
/* Functions internal to the PCI core code */
extern int pci_uevent(struct device *dev, struct kobj_uevent_env *env);
extern int pci_create_sysfs_dev_files(struct pci_dev *pdev);
extern void pci_remove_sysfs_dev_files(struct pci_dev *pdev);
extern void pci_cleanup_rom(struct pci_dev *dev);
#ifdef HAVE_PCI_MMAP
extern int pci_mmap_fits(struct pci_dev *pdev, int resno,
struct vm_area_struct *vma);
#endif
int pci_probe_reset_function(struct pci_dev *dev);
/**
* struct pci_platform_pm_ops - Firmware PM callbacks
*
* @is_manageable: returns 'true' if given device is power manageable by the
* platform firmware
*
* @set_state: invokes the platform firmware to set the device's power state
*
* @choose_state: returns PCI power state of given device preferred by the
* platform; to be used during system-wide transitions from a
* sleeping state to the working state and vice versa
*
* @can_wakeup: returns 'true' if given device is capable of waking up the
* system from a sleeping state
*
* @sleep_wake: enables/disables the system wake up capability of given device
*
* @run_wake: enables/disables the platform to generate run-time wake-up events
* for given device (the device's wake-up capability has to be
* enabled by @sleep_wake for this feature to work)
*
* If given platform is generally capable of power managing PCI devices, all of
* these callbacks are mandatory.
*/
struct pci_platform_pm_ops {
bool (*is_manageable)(struct pci_dev *dev);
int (*set_state)(struct pci_dev *dev, pci_power_t state);
pci_power_t (*choose_state)(struct pci_dev *dev);
bool (*can_wakeup)(struct pci_dev *dev);
int (*sleep_wake)(struct pci_dev *dev, bool enable);
int (*run_wake)(struct pci_dev *dev, bool enable);
};
extern int pci_set_platform_pm(struct pci_platform_pm_ops *ops);
extern void pci_update_current_state(struct pci_dev *dev, pci_power_t state);
extern void pci_disable_enabled_device(struct pci_dev *dev);
extern bool pci_check_pme_status(struct pci_dev *dev);
extern int pci_finish_runtime_suspend(struct pci_dev *dev);
extern void pci_wakeup_event(struct pci_dev *dev);
extern int __pci_pme_wakeup(struct pci_dev *dev, void *ign);
extern void pci_pme_wakeup_bus(struct pci_bus *bus);
extern void pci_pm_init(struct pci_dev *dev);
extern void platform_pci_wakeup_init(struct pci_dev *dev);
extern void pci_allocate_cap_save_buffers(struct pci_dev *dev);
static inline bool pci_is_bridge(struct pci_dev *pci_dev)
{
return !!(pci_dev->subordinate);
}
extern int pci_user_read_config_byte(struct pci_dev *dev, int where, u8 *val);
extern int pci_user_read_config_word(struct pci_dev *dev, int where, u16 *val);
extern int pci_user_read_config_dword(struct pci_dev *dev, int where, u32 *val);
extern int pci_user_write_config_byte(struct pci_dev *dev, int where, u8 val);
extern int pci_user_write_config_word(struct pci_dev *dev, int where, u16 val);
extern int pci_user_write_config_dword(struct pci_dev *dev, int where, u32 val);
struct pci_vpd_ops {
ssize_t (*read)(struct pci_dev *dev, loff_t pos, size_t count, void *buf);
ssize_t (*write)(struct pci_dev *dev, loff_t pos, size_t count, const void *buf);
void (*release)(struct pci_dev *dev);
};
struct pci_vpd {
unsigned int len;
const struct pci_vpd_ops *ops;
struct bin_attribute *attr; /* descriptor for sysfs VPD entry */
};
extern int pci_vpd_pci22_init(struct pci_dev *dev);
static inline void pci_vpd_release(struct pci_dev *dev)
{
if (dev->vpd)
dev->vpd->ops->release(dev);
}
/* PCI /proc functions */
#ifdef CONFIG_PROC_FS
extern int pci_proc_attach_device(struct pci_dev *dev);
extern int pci_proc_detach_device(struct pci_dev *dev);
extern int pci_proc_detach_bus(struct pci_bus *bus);
#else
static inline int pci_proc_attach_device(struct pci_dev *dev) { return 0; }
static inline int pci_proc_detach_device(struct pci_dev *dev) { return 0; }
static inline int pci_proc_detach_bus(struct pci_bus *bus) { return 0; }
#endif
/* Functions for PCI Hotplug drivers to use */
extern unsigned int pci_do_scan_bus(struct pci_bus *bus);
#ifdef HAVE_PCI_LEGACY
extern void pci_create_legacy_files(struct pci_bus *bus);
extern void pci_remove_legacy_files(struct pci_bus *bus);
#else
static inline void pci_create_legacy_files(struct pci_bus *bus) { return; }
static inline void pci_remove_legacy_files(struct pci_bus *bus) { return; }
#endif
/* Lock for read/write access to pci device and bus lists */
extern struct rw_semaphore pci_bus_sem;
extern unsigned int pci_pm_d3_delay;
#ifdef CONFIG_PCI_MSI
void pci_no_msi(void);
extern void pci_msi_init_pci_dev(struct pci_dev *dev);
#else
static inline void pci_no_msi(void) { }
static inline void pci_msi_init_pci_dev(struct pci_dev *dev) { }
#endif
#ifdef CONFIG_PCIEAER
void pci_no_aer(void);
#else
static inline void pci_no_aer(void) { }
#endif
static inline int pci_no_d1d2(struct pci_dev *dev)
{
unsigned int parent_dstates = 0;
if (dev->bus->self)
parent_dstates = dev->bus->self->no_d1d2;
return (dev->no_d1d2 || parent_dstates);
}
extern struct device_attribute pci_dev_attrs[];
extern struct device_attribute dev_attr_cpuaffinity;
extern struct device_attribute dev_attr_cpulistaffinity;
#ifdef CONFIG_HOTPLUG
extern struct bus_attribute pci_bus_attrs[];
#else
#define pci_bus_attrs NULL
#endif
/**
* pci_match_one_device - Tell if a PCI device structure has a matching
* PCI device id structure
* @id: single PCI device id structure to match
* @dev: the PCI device structure to match against
*
* Returns the matching pci_device_id structure or %NULL if there is no match.
*/
static inline const struct pci_device_id *
pci_match_one_device(const struct pci_device_id *id, const struct pci_dev *dev)
{
if ((id->vendor == PCI_ANY_ID || id->vendor == dev->vendor) &&
(id->device == PCI_ANY_ID || id->device == dev->device) &&
(id->subvendor == PCI_ANY_ID || id->subvendor == dev->subsystem_vendor) &&
(id->subdevice == PCI_ANY_ID || id->subdevice == dev->subsystem_device) &&
!((id->class ^ dev->class) & id->class_mask))
return id;
return NULL;
}
struct pci_dev *pci_find_upstream_pcie_bridge(struct pci_dev *pdev);
/* PCI slot sysfs helper code */
#define to_pci_slot(s) container_of(s, struct pci_slot, kobj)
extern struct kset *pci_slots_kset;
struct pci_slot_attribute {
struct attribute attr;
ssize_t (*show)(struct pci_slot *, char *);
ssize_t (*store)(struct pci_slot *, const char *, size_t);
};
#define to_pci_slot_attr(s) container_of(s, struct pci_slot_attribute, attr)
enum pci_bar_type {
pci_bar_unknown, /* Standard PCI BAR probe */
pci_bar_io, /* An io port BAR */
pci_bar_mem32, /* A 32-bit memory BAR */
pci_bar_mem64, /* A 64-bit memory BAR */
};
extern int pci_setup_device(struct pci_dev *dev);
extern int __pci_read_base(struct pci_dev *dev, enum pci_bar_type type,
struct resource *res, unsigned int reg);
extern int pci_resource_bar(struct pci_dev *dev, int resno,
enum pci_bar_type *type);
extern int pci_bus_add_child(struct pci_bus *bus);
extern void pci_enable_ari(struct pci_dev *dev);
/**
* pci_ari_enabled - query ARI forwarding status
* @bus: the PCI bus
*
* Returns 1 if ARI forwarding is enabled, or 0 if not enabled;
*/
static inline int pci_ari_enabled(struct pci_bus *bus)
{
return bus->self && bus->self->ari_enabled;
}
#ifdef CONFIG_PCI_QUIRKS
extern int pci_is_reassigndev(struct pci_dev *dev);
resource_size_t pci_specified_resource_alignment(struct pci_dev *dev);
extern void pci_disable_bridge_window(struct pci_dev *dev);
#endif
/* Single Root I/O Virtualization */
struct pci_sriov {
int pos; /* capability position */
int nres; /* number of resources */
u32 cap; /* SR-IOV Capabilities */
u16 ctrl; /* SR-IOV Control */
u16 total; /* total VFs associated with the PF */
u16 initial; /* initial VFs associated with the PF */
u16 nr_virtfn; /* number of VFs available */
u16 offset; /* first VF Routing ID offset */
u16 stride; /* following VF stride */
u32 pgsz; /* page size for BAR alignment */
u8 link; /* Function Dependency Link */
struct pci_dev *dev; /* lowest numbered PF */
struct pci_dev *self; /* this PF */
struct mutex lock; /* lock for VF bus */
struct work_struct mtask; /* VF Migration task */
u8 __iomem *mstate; /* VF Migration State Array */
};
/* Address Translation Service */
struct pci_ats {
int pos; /* capability position */
int stu; /* Smallest Translation Unit */
int qdep; /* Invalidate Queue Depth */
int ref_cnt; /* Physical Function reference count */
unsigned int is_enabled:1; /* Enable bit is set */
};
#ifdef CONFIG_PCI_IOV
extern int pci_iov_init(struct pci_dev *dev);
extern void pci_iov_release(struct pci_dev *dev);
extern int pci_iov_resource_bar(struct pci_dev *dev, int resno,
enum pci_bar_type *type);
extern int pci_sriov_resource_alignment(struct pci_dev *dev, int resno);
extern void pci_restore_iov_state(struct pci_dev *dev);
extern int pci_iov_bus_range(struct pci_bus *bus);
extern int pci_enable_ats(struct pci_dev *dev, int ps);
extern void pci_disable_ats(struct pci_dev *dev);
extern int pci_ats_queue_depth(struct pci_dev *dev);
/**
* pci_ats_enabled - query the ATS status
* @dev: the PCI device
*
* Returns 1 if ATS capability is enabled, or 0 if not.
*/
static inline int pci_ats_enabled(struct pci_dev *dev)
{
return dev->ats && dev->ats->is_enabled;
}
#else
static inline int pci_iov_init(struct pci_dev *dev)
{
return -ENODEV;
}
static inline void pci_iov_release(struct pci_dev *dev)
{
}
static inline int pci_iov_resource_bar(struct pci_dev *dev, int resno,
enum pci_bar_type *type)
{
return 0;
}
static inline void pci_restore_iov_state(struct pci_dev *dev)
{
}
static inline int pci_iov_bus_range(struct pci_bus *bus)
{
return 0;
}
static inline int pci_enable_ats(struct pci_dev *dev, int ps)
{
return -ENODEV;
}
static inline void pci_disable_ats(struct pci_dev *dev)
{
}
static inline int pci_ats_queue_depth(struct pci_dev *dev)
{
return -ENODEV;
}
static inline int pci_ats_enabled(struct pci_dev *dev)
{
return 0;
}
#endif /* CONFIG_PCI_IOV */
static inline int pci_resource_alignment(struct pci_dev *dev,
struct resource *res)
{
#ifdef CONFIG_PCI_IOV
int resno = res - dev->resource;
if (resno >= PCI_IOV_RESOURCES && resno <= PCI_IOV_RESOURCE_END)
return pci_sriov_resource_alignment(dev, resno);
#endif
return resource_alignment(res);
}
extern void pci_enable_acs(struct pci_dev *dev);
struct pci_dev_reset_methods {
u16 vendor;
u16 device;
int (*reset)(struct pci_dev *dev, int probe);
};
#ifdef CONFIG_PCI_QUIRKS
extern int pci_dev_specific_reset(struct pci_dev *dev, int probe);
#else
static inline int pci_dev_specific_reset(struct pci_dev *dev, int probe)
{
return -ENOTTY;
}
#endif
#endif /* DRIVERS_PCI_H */
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