xen: Rename the balloon lock

* xen_create_contiguous_region needs access to the balloon lock to
  ensure memory doesn't change under its feet, so expose the balloon
  lock
* Change the name of the lock to xen_reservation_lock, to imply it's
  now less-specific usage.

[ Impact: cleanup ]

Signed-off-by: Alex Nixon <alex.nixon@citrix.com>
Signed-off-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
This commit is contained in:
Alex Nixon 2009-02-09 12:05:46 -08:00 committed by Konrad Rzeszutek Wilk
parent 7347b4082e
commit 19001c8c5b
3 changed files with 19 additions and 11 deletions

View File

@ -70,6 +70,13 @@
#define MMU_UPDATE_HISTO 30
/*
* Protects atomic reservation decrease/increase against concurrent increases.
* Also protects non-atomic updates of current_pages and driver_pages, and
* balloon lists.
*/
DEFINE_SPINLOCK(xen_reservation_lock);
#ifdef CONFIG_XEN_DEBUG_FS
static struct {

View File

@ -85,13 +85,6 @@ static struct sys_device balloon_sysdev;
static int register_balloon(struct sys_device *sysdev);
/*
* Protects atomic reservation decrease/increase against concurrent increases.
* Also protects non-atomic updates of current_pages and driver_pages, and
* balloon lists.
*/
static DEFINE_SPINLOCK(balloon_lock);
static struct balloon_stats balloon_stats;
/* We increase/decrease in batches which fit in a page */
@ -210,7 +203,7 @@ static int increase_reservation(unsigned long nr_pages)
if (nr_pages > ARRAY_SIZE(frame_list))
nr_pages = ARRAY_SIZE(frame_list);
spin_lock_irqsave(&balloon_lock, flags);
spin_lock_irqsave(&xen_reservation_lock, flags);
page = balloon_first_page();
for (i = 0; i < nr_pages; i++) {
@ -254,7 +247,7 @@ static int increase_reservation(unsigned long nr_pages)
balloon_stats.current_pages += rc;
out:
spin_unlock_irqrestore(&balloon_lock, flags);
spin_unlock_irqrestore(&xen_reservation_lock, flags);
return rc < 0 ? rc : rc != nr_pages;
}
@ -299,7 +292,7 @@ static int decrease_reservation(unsigned long nr_pages)
kmap_flush_unused();
flush_tlb_all();
spin_lock_irqsave(&balloon_lock, flags);
spin_lock_irqsave(&xen_reservation_lock, flags);
/* No more mappings: invalidate P2M and add to balloon. */
for (i = 0; i < nr_pages; i++) {
@ -315,7 +308,7 @@ static int decrease_reservation(unsigned long nr_pages)
balloon_stats.current_pages -= nr_pages;
spin_unlock_irqrestore(&balloon_lock, flags);
spin_unlock_irqrestore(&xen_reservation_lock, flags);
return need_sleep;
}

View File

@ -9,6 +9,8 @@
#ifndef __XEN_PUBLIC_MEMORY_H__
#define __XEN_PUBLIC_MEMORY_H__
#include <linux/spinlock.h>
/*
* Increase or decrease the specified domain's memory reservation. Returns a
* -ve errcode on failure, or the # extents successfully allocated or freed.
@ -142,4 +144,10 @@ struct xen_translate_gpfn_list {
};
DEFINE_GUEST_HANDLE_STRUCT(xen_translate_gpfn_list);
/*
* Prevent the balloon driver from changing the memory reservation
* during a driver critical region.
*/
extern spinlock_t xen_reservation_lock;
#endif /* __XEN_PUBLIC_MEMORY_H__ */