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linux/drivers/xen/xen-pciback/pciback.h
Konrad Rzeszutek Wilk b1766b6289 xen/pciback: Use mutexes when working with Xenbus state transitions. 
The caller that orchestrates the state changes is xenwatch_thread
and it takes a mutex. In our processing of Xenbus states we can take
the luxery of going to sleep on a mutex, so lets do that and
also fix this bug:

BUG: sleeping function called from invalid context at /linux/kernel/mutex.c:271
in_atomic(): 1, irqs_disabled(): 0, pid: 32, name: xenwatch
2 locks held by xenwatch/32:
 #0:  (xenwatch_mutex){......}, at: [<ffffffff813856ab>] xenwatch_thread+0x4b/0x180
 #1:  (&(&pdev->dev_lock)->rlock){......}, at: [<ffffffff8138f05b>] xen_pcibk_disconnect+0x1b/0x80
Pid: 32, comm: xenwatch Not tainted 3.1.0-rc6-00015-g3ce340d #2
Call Trace:
 [<ffffffff810892b2>] __might_sleep+0x102/0x130
 [<ffffffff8163b90f>] mutex_lock_nested+0x2f/0x50
 [<ffffffff81382c1c>] unbind_from_irq+0x2c/0x1b0
 [<ffffffff8110da66>] ? free_irq+0x56/0xb0
 [<ffffffff81382dbc>] unbind_from_irqhandler+0x1c/0x30
 [<ffffffff8138f06b>] xen_pcibk_disconnect+0x2b/0x80
 [<ffffffff81390348>] xen_pcibk_frontend_changed+0xe8/0x140
 [<ffffffff81387ac2>] xenbus_otherend_changed+0xd2/0x150
 [<ffffffff810895c1>] ? get_parent_ip+0x11/0x50
 [<ffffffff81387de0>] frontend_changed+0x10/0x20
 [<ffffffff81385712>] xenwatch_thread+0xb2/0x180

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
2011-09-21 18:18:16 -04:00

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/*
* PCI Backend Common Data Structures & Function Declarations
*
* Author: Ryan Wilson <hap9@epoch.ncsc.mil>
*/
#ifndef __XEN_PCIBACK_H__
#define __XEN_PCIBACK_H__
#include <linux/pci.h>
#include <linux/interrupt.h>
#include <xen/xenbus.h>
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/workqueue.h>
#include <linux/atomic.h>
#include <xen/interface/io/pciif.h>
#define DRV_NAME "xen-pciback"
struct pci_dev_entry {
struct list_head list;
struct pci_dev *dev;
};
#define _PDEVF_op_active (0)
#define PDEVF_op_active (1<<(_PDEVF_op_active))
#define _PCIB_op_pending (1)
#define PCIB_op_pending (1<<(_PCIB_op_pending))
struct xen_pcibk_device {
void *pci_dev_data;
struct mutex dev_lock;
struct xenbus_device *xdev;
struct xenbus_watch be_watch;
u8 be_watching;
int evtchn_irq;
struct xen_pci_sharedinfo *sh_info;
unsigned long flags;
struct work_struct op_work;
};
struct xen_pcibk_dev_data {
struct list_head config_fields;
unsigned int permissive:1;
unsigned int warned_on_write:1;
unsigned int enable_intx:1;
unsigned int isr_on:1; /* Whether the IRQ handler is installed. */
unsigned int ack_intr:1; /* .. and ACK-ing */
unsigned long handled;
unsigned int irq; /* Saved in case device transitions to MSI/MSI-X */
char irq_name[0]; /* xen-pcibk[000:04:00.0] */
};
/* Used by XenBus and xen_pcibk_ops.c */
extern wait_queue_head_t xen_pcibk_aer_wait_queue;
extern struct workqueue_struct *xen_pcibk_wq;
/* Used by pcistub.c and conf_space_quirks.c */
extern struct list_head xen_pcibk_quirks;
/* Get/Put PCI Devices that are hidden from the PCI Backend Domain */
struct pci_dev *pcistub_get_pci_dev_by_slot(struct xen_pcibk_device *pdev,
int domain, int bus,
int slot, int func);
struct pci_dev *pcistub_get_pci_dev(struct xen_pcibk_device *pdev,
struct pci_dev *dev);
void pcistub_put_pci_dev(struct pci_dev *dev);
/* Ensure a device is turned off or reset */
void xen_pcibk_reset_device(struct pci_dev *pdev);
/* Access a virtual configuration space for a PCI device */
int xen_pcibk_config_init(void);
int xen_pcibk_config_init_dev(struct pci_dev *dev);
void xen_pcibk_config_free_dyn_fields(struct pci_dev *dev);
void xen_pcibk_config_reset_dev(struct pci_dev *dev);
void xen_pcibk_config_free_dev(struct pci_dev *dev);
int xen_pcibk_config_read(struct pci_dev *dev, int offset, int size,
u32 *ret_val);
int xen_pcibk_config_write(struct pci_dev *dev, int offset, int size,
u32 value);
/* Handle requests for specific devices from the frontend */
typedef int (*publish_pci_dev_cb) (struct xen_pcibk_device *pdev,
unsigned int domain, unsigned int bus,
unsigned int devfn, unsigned int devid);
typedef int (*publish_pci_root_cb) (struct xen_pcibk_device *pdev,
unsigned int domain, unsigned int bus);
/* Backend registration for the two types of BDF representation:
* vpci - BDFs start at 00
* passthrough - BDFs are exactly like in the host.
*/
struct xen_pcibk_backend {
const char *name;
int (*init)(struct xen_pcibk_device *pdev);
void (*free)(struct xen_pcibk_device *pdev);
int (*find)(struct pci_dev *pcidev, struct xen_pcibk_device *pdev,
unsigned int *domain, unsigned int *bus,
unsigned int *devfn);
int (*publish)(struct xen_pcibk_device *pdev, publish_pci_root_cb cb);
void (*release)(struct xen_pcibk_device *pdev, struct pci_dev *dev);
int (*add)(struct xen_pcibk_device *pdev, struct pci_dev *dev,
int devid, publish_pci_dev_cb publish_cb);
struct pci_dev *(*get)(struct xen_pcibk_device *pdev,
unsigned int domain, unsigned int bus,
unsigned int devfn);
};
extern const struct xen_pcibk_backend xen_pcibk_vpci_backend;
extern const struct xen_pcibk_backend xen_pcibk_passthrough_backend;
extern const struct xen_pcibk_backend *xen_pcibk_backend;
static inline int xen_pcibk_add_pci_dev(struct xen_pcibk_device *pdev,
struct pci_dev *dev,
int devid,
publish_pci_dev_cb publish_cb)
{
if (xen_pcibk_backend && xen_pcibk_backend->add)
return xen_pcibk_backend->add(pdev, dev, devid, publish_cb);
return -1;
}
static inline void xen_pcibk_release_pci_dev(struct xen_pcibk_device *pdev,
struct pci_dev *dev)
{
if (xen_pcibk_backend && xen_pcibk_backend->free)
return xen_pcibk_backend->release(pdev, dev);
}
static inline struct pci_dev *
xen_pcibk_get_pci_dev(struct xen_pcibk_device *pdev, unsigned int domain,
unsigned int bus, unsigned int devfn)
{
if (xen_pcibk_backend && xen_pcibk_backend->get)
return xen_pcibk_backend->get(pdev, domain, bus, devfn);
return NULL;
}
/**
* Add for domain0 PCIE-AER handling. Get guest domain/bus/devfn in xen_pcibk
* before sending aer request to pcifront, so that guest could identify
* device, coopearte with xen_pcibk to finish aer recovery job if device driver
* has the capability
*/
static inline int xen_pcibk_get_pcifront_dev(struct pci_dev *pcidev,
struct xen_pcibk_device *pdev,
unsigned int *domain,
unsigned int *bus,
unsigned int *devfn)
{
if (xen_pcibk_backend && xen_pcibk_backend->find)
return xen_pcibk_backend->find(pcidev, pdev, domain, bus,
devfn);
return -1;
}
static inline int xen_pcibk_init_devices(struct xen_pcibk_device *pdev)
{
if (xen_pcibk_backend && xen_pcibk_backend->init)
return xen_pcibk_backend->init(pdev);
return -1;
}
static inline int xen_pcibk_publish_pci_roots(struct xen_pcibk_device *pdev,
publish_pci_root_cb cb)
{
if (xen_pcibk_backend && xen_pcibk_backend->publish)
return xen_pcibk_backend->publish(pdev, cb);
return -1;
}
static inline void xen_pcibk_release_devices(struct xen_pcibk_device *pdev)
{
if (xen_pcibk_backend && xen_pcibk_backend->free)
return xen_pcibk_backend->free(pdev);
}
/* Handles events from front-end */
irqreturn_t xen_pcibk_handle_event(int irq, void *dev_id);
void xen_pcibk_do_op(struct work_struct *data);
int xen_pcibk_xenbus_register(void);
void xen_pcibk_xenbus_unregister(void);
extern int verbose_request;
void xen_pcibk_test_and_schedule_op(struct xen_pcibk_device *pdev);
#endif
/* Handles shared IRQs that can to device domain and control domain. */
void xen_pcibk_irq_handler(struct pci_dev *dev, int reset);
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