#if LINUX_VERSION_CODE >= KERNEL_VERSION(2,6,0)
/* Use the private and mapping fields of struct page as a list. */
-#define PAGE_TO_LIST(p) ( (struct list_head *)&p->private )
-#define LIST_TO_PAGE(l) ( list_entry( ((unsigned long *)l), \
- struct page, private ) )
-#define UNLIST_PAGE(p) do { list_del(PAGE_TO_LIST(p)); \
- p->mapping = NULL; \
- p->private = 0; } while(0)
+#define PAGE_TO_LIST(p) ((struct list_head *)&p->private)
+#define LIST_TO_PAGE(l) \
+ (list_entry(((unsigned long *)l), struct page, private))
+#define UNLIST_PAGE(p) \
+ do { \
+ list_del(PAGE_TO_LIST(p)); \
+ p->mapping = NULL; \
+ p->private = 0; \
+ } while(0)
#else
/* There's a dedicated list field in struct page we can use. */
#define PAGE_TO_LIST(p) ( &p->list )
#endif
#define IPRINTK(fmt, args...) \
- printk(KERN_INFO "xen_mem: " fmt, ##args)
+ printk(KERN_INFO "xen_mem: " fmt, ##args)
#define WPRINTK(fmt, args...) \
- printk(KERN_WARNING "xen_mem: " fmt, ##args)
+ printk(KERN_WARNING "xen_mem: " fmt, ##args)
/* balloon_append: add the given page to the balloon. */
static void balloon_append(struct page *page)
{
- /* Low memory is re-populated first, so highmem pages go at list tail. */
- if ( PageHighMem(page) )
- {
- list_add_tail(PAGE_TO_LIST(page), &ballooned_pages);
- balloon_high++;
- }
- else
- {
- list_add(PAGE_TO_LIST(page), &ballooned_pages);
- balloon_low++;
- }
+ /* Lowmem is re-populated first, so highmem pages go at list tail. */
+ if (PageHighMem(page)) {
+ list_add_tail(PAGE_TO_LIST(page), &ballooned_pages);
+ balloon_high++;
+ } else {
+ list_add(PAGE_TO_LIST(page), &ballooned_pages);
+ balloon_low++;
+ }
}
/* balloon_retrieve: rescue a page from the balloon, if it is not empty. */
static struct page *balloon_retrieve(void)
{
- struct page *page;
+ struct page *page;
- if ( list_empty(&ballooned_pages) )
- return NULL;
+ if (list_empty(&ballooned_pages))
+ return NULL;
- page = LIST_TO_PAGE(ballooned_pages.next);
- UNLIST_PAGE(page);
+ page = LIST_TO_PAGE(ballooned_pages.next);
+ UNLIST_PAGE(page);
- if ( PageHighMem(page) )
- balloon_high--;
- else
- balloon_low--;
+ if (PageHighMem(page))
+ balloon_high--;
+ else
+ balloon_low--;
- return page;
+ return page;
}
static void balloon_alarm(unsigned long unused)
{
- schedule_work(&balloon_worker);
+ schedule_work(&balloon_worker);
}
static unsigned long current_target(void)
{
- unsigned long target = min(target_pages, hard_limit);
- if ( target > (current_pages + balloon_low + balloon_high) )
- target = current_pages + balloon_low + balloon_high;
- return target;
+ unsigned long target = min(target_pages, hard_limit);
+ if (target > (current_pages + balloon_low + balloon_high))
+ target = current_pages + balloon_low + balloon_high;
+ return target;
}
/*
*/
static void balloon_process(void *unused)
{
- unsigned long *mfn_list, pfn, i, flags;
- struct page *page;
- long credit, debt, rc;
- void *v;
+ unsigned long *mfn_list, pfn, i, flags;
+ struct page *page;
+ long credit, debt, rc;
+ void *v;
- down(&balloon_mutex);
+ down(&balloon_mutex);
retry:
- mfn_list = NULL;
-
- if ( (credit = current_target() - current_pages) > 0 )
- {
- mfn_list = (unsigned long *)vmalloc(credit * sizeof(*mfn_list));
- if ( mfn_list == NULL )
- goto out;
-
- balloon_lock(flags);
- rc = HYPERVISOR_dom_mem_op(
- MEMOP_increase_reservation, mfn_list, credit, 0);
- balloon_unlock(flags);
- if ( rc < credit )
- {
- /* We hit the Xen hard limit: reprobe. */
- if ( HYPERVISOR_dom_mem_op(
- MEMOP_decrease_reservation, mfn_list, rc, 0) != rc )
- BUG();
- hard_limit = current_pages + rc - driver_pages;
- vfree(mfn_list);
- goto retry;
- }
-
- for ( i = 0; i < credit; i++ )
- {
- if ( (page = balloon_retrieve()) == NULL )
- BUG();
-
- pfn = page - mem_map;
- if ( phys_to_machine_mapping[pfn] != INVALID_P2M_ENTRY )
- BUG();
-
- /* Update P->M and M->P tables. */
- phys_to_machine_mapping[pfn] = mfn_list[i];
- xen_machphys_update(mfn_list[i], pfn);
+ mfn_list = NULL;
+
+ if ((credit = current_target() - current_pages) > 0) {
+ mfn_list = vmalloc(credit * sizeof(*mfn_list));
+ if (mfn_list == NULL)
+ goto out;
+
+ balloon_lock(flags);
+ rc = HYPERVISOR_dom_mem_op(
+ MEMOP_increase_reservation, mfn_list, credit, 0);
+ balloon_unlock(flags);
+ if (rc < credit) {
+ /* We hit the Xen hard limit: reprobe. */
+ BUG_ON(HYPERVISOR_dom_mem_op(
+ MEMOP_decrease_reservation,
+ mfn_list, rc, 0) != rc);
+ hard_limit = current_pages + rc - driver_pages;
+ vfree(mfn_list);
+ goto retry;
+ }
+
+ for (i = 0; i < credit; i++) {
+ page = balloon_retrieve();
+ BUG_ON(page == NULL);
+
+ pfn = page - mem_map;
+ if (phys_to_machine_mapping[pfn] != INVALID_P2M_ENTRY)
+ BUG();
+
+ /* Update P->M and M->P tables. */
+ phys_to_machine_mapping[pfn] = mfn_list[i];
+ xen_machphys_update(mfn_list[i], pfn);
- /* Link back into the page tables if it's not a highmem page. */
- if ( pfn < max_low_pfn )
- {
- BUG_ON(HYPERVISOR_update_va_mapping(
- (unsigned long)__va(pfn << PAGE_SHIFT),
- pfn_pte_ma(mfn_list[i], PAGE_KERNEL), 0));
- }
-
- /* Finally, relinquish the memory back to the system allocator. */
- ClearPageReserved(page);
- set_page_count(page, 1);
- __free_page(page);
- }
-
- current_pages += credit;
- }
- else if ( credit < 0 )
- {
- debt = -credit;
-
- mfn_list = (unsigned long *)vmalloc(debt * sizeof(*mfn_list));
- if ( mfn_list == NULL )
- goto out;
-
- for ( i = 0; i < debt; i++ )
- {
- if ( (page = alloc_page(GFP_HIGHUSER)) == NULL )
- {
- debt = i;
- break;
- }
-
- pfn = page - mem_map;
- mfn_list[i] = phys_to_machine_mapping[pfn];
-
- if ( !PageHighMem(page) )
- {
- v = phys_to_virt(pfn << PAGE_SHIFT);
- scrub_pages(v, 1);
- BUG_ON(HYPERVISOR_update_va_mapping(
- (unsigned long)v, __pte_ma(0), 0));
- }
+ /* Link back into the page tables if not highmem. */
+ if (pfn < max_low_pfn)
+ BUG_ON(HYPERVISOR_update_va_mapping(
+ (unsigned long)__va(pfn << PAGE_SHIFT),
+ pfn_pte_ma(mfn_list[i], PAGE_KERNEL),
+ 0));
+
+ /* Relinquish the page back to the allocator. */
+ ClearPageReserved(page);
+ set_page_count(page, 1);
+ __free_page(page);
+ }
+
+ current_pages += credit;
+ } else if (credit < 0) {
+ debt = -credit;
+
+ mfn_list = vmalloc(debt * sizeof(*mfn_list));
+ if (mfn_list == NULL)
+ goto out;
+
+ for (i = 0; i < debt; i++) {
+ if ((page = alloc_page(GFP_HIGHUSER)) == NULL) {
+ debt = i;
+ break;
+ }
+
+ pfn = page - mem_map;
+ mfn_list[i] = phys_to_machine_mapping[pfn];
+
+ if (!PageHighMem(page)) {
+ v = phys_to_virt(pfn << PAGE_SHIFT);
+ scrub_pages(v, 1);
+ BUG_ON(HYPERVISOR_update_va_mapping(
+ (unsigned long)v, __pte_ma(0), 0));
+ }
#ifdef CONFIG_XEN_SCRUB_PAGES
- else
- {
- v = kmap(page);
- scrub_pages(v, 1);
- kunmap(page);
- }
+ else {
+ v = kmap(page);
+ scrub_pages(v, 1);
+ kunmap(page);
+ }
#endif
- }
+ }
- /* Ensure that ballooned highmem pages don't have cached mappings. */
- kmap_flush_unused();
- flush_tlb_all();
+ /* Ensure that ballooned highmem pages don't have kmaps. */
+ kmap_flush_unused();
+ flush_tlb_all();
- /* No more mappings: invalidate pages in P2M and add to balloon. */
- for ( i = 0; i < debt; i++ )
- {
- pfn = mfn_to_pfn(mfn_list[i]);
- phys_to_machine_mapping[pfn] = INVALID_P2M_ENTRY;
- balloon_append(pfn_to_page(pfn));
- }
+ /* No more mappings: invalidate P2M and add to balloon. */
+ for (i = 0; i < debt; i++) {
+ pfn = mfn_to_pfn(mfn_list[i]);
+ phys_to_machine_mapping[pfn] = INVALID_P2M_ENTRY;
+ balloon_append(pfn_to_page(pfn));
+ }
- if ( HYPERVISOR_dom_mem_op(
- MEMOP_decrease_reservation, mfn_list, debt, 0) != debt )
- BUG();
+ BUG_ON(HYPERVISOR_dom_mem_op(
+ MEMOP_decrease_reservation,mfn_list, debt, 0) != debt);
- current_pages -= debt;
- }
+ current_pages -= debt;
+ }
out:
- if ( mfn_list != NULL )
- vfree(mfn_list);
+ if (mfn_list != NULL)
+ vfree(mfn_list);
- /* Schedule more work if there is some still to be done. */
- if ( current_target() != current_pages )
- mod_timer(&balloon_timer, jiffies + HZ);
+ /* Schedule more work if there is some still to be done. */
+ if (current_target() != current_pages)
+ mod_timer(&balloon_timer, jiffies + HZ);
- up(&balloon_mutex);
+ up(&balloon_mutex);
}
/* Resets the Xen limit, sets new target, and kicks off processing. */
static void set_new_target(unsigned long target)
{
- /* No need for lock. Not read-modify-write updates. */
- hard_limit = ~0UL;
- target_pages = target;
- schedule_work(&balloon_worker);
+ /* No need for lock. Not read-modify-write updates. */
+ hard_limit = ~0UL;
+ target_pages = target;
+ schedule_work(&balloon_worker);
}
static struct xenbus_watch target_watch =
{
- .node = "memory/target"
+ .node = "memory/target"
};
/* React to a change in the target key */
static void watch_target(struct xenbus_watch *watch, const char *node)
{
- unsigned long new_target;
- int err;
-
- err = xenbus_scanf("memory", "target", "%lu", &new_target);
+ unsigned long new_target;
+ int err;
+
+ err = xenbus_scanf("memory", "target", "%lu", &new_target);
+ if (err != 1) {
+ printk(KERN_ERR "Unable to read memory/target\n");
+ return;
+ }
- if(err != 1)
- {
- printk(KERN_ERR "Unable to read memory/target\n");
- return;
- }
-
- set_new_target(new_target >> PAGE_SHIFT);
+ set_new_target(new_target >> PAGE_SHIFT);
}
unsigned long event,
void *data)
{
- int err;
-
- BUG_ON(down_trylock(&xenbus_lock) == 0);
+ int err;
- err = register_xenbus_watch(&target_watch);
+ BUG_ON(down_trylock(&xenbus_lock) == 0);
- if (err) {
- printk(KERN_ERR "Failed to set balloon watcher\n");
- }
+ err = register_xenbus_watch(&target_watch);
+ if (err)
+ printk(KERN_ERR "Failed to set balloon watcher\n");
- return NOTIFY_DONE;
+ return NOTIFY_DONE;
}
static int balloon_write(struct file *file, const char __user *buffer,
unsigned long count, void *data)
{
- char memstring[64], *endchar;
- unsigned long long target_bytes;
+ char memstring[64], *endchar;
+ unsigned long long target_bytes;
- if ( !capable(CAP_SYS_ADMIN) )
- return -EPERM;
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
- if ( count <= 1 )
- return -EBADMSG; /* runt */
- if ( count > sizeof(memstring) )
- return -EFBIG; /* too long */
+ if (count <= 1)
+ return -EBADMSG; /* runt */
+ if (count > sizeof(memstring))
+ return -EFBIG; /* too long */
- if ( copy_from_user(memstring, buffer, count) )
- return -EFAULT;
- memstring[sizeof(memstring)-1] = '\0';
+ if (copy_from_user(memstring, buffer, count))
+ return -EFAULT;
+ memstring[sizeof(memstring)-1] = '\0';
- target_bytes = memparse(memstring, &endchar);
- set_new_target(target_bytes >> PAGE_SHIFT);
+ target_bytes = memparse(memstring, &endchar);
+ set_new_target(target_bytes >> PAGE_SHIFT);
- return count;
+ return count;
}
static int balloon_read(char *page, char **start, off_t off,
int count, int *eof, void *data)
{
- int len;
-
- len = sprintf(
- page,
- "Current allocation: %8lu kB\n"
- "Requested target: %8lu kB\n"
- "Low-mem balloon: %8lu kB\n"
- "High-mem balloon: %8lu kB\n"
- "Xen hard limit: ",
- PAGES2KB(current_pages), PAGES2KB(target_pages),
- PAGES2KB(balloon_low), PAGES2KB(balloon_high));
-
- if ( hard_limit != ~0UL )
- len += sprintf(
- page + len,
- "%8lu kB (inc. %8lu kB driver headroom)\n",
- PAGES2KB(hard_limit), PAGES2KB(driver_pages));
- else
- len += sprintf(
- page + len,
- " ??? kB\n");
-
- *eof = 1;
- return len;
+ int len;
+
+ len = sprintf(
+ page,
+ "Current allocation: %8lu kB\n"
+ "Requested target: %8lu kB\n"
+ "Low-mem balloon: %8lu kB\n"
+ "High-mem balloon: %8lu kB\n"
+ "Xen hard limit: ",
+ PAGES2KB(current_pages), PAGES2KB(target_pages),
+ PAGES2KB(balloon_low), PAGES2KB(balloon_high));
+
+ if (hard_limit != ~0UL) {
+ len += sprintf(
+ page + len,
+ "%8lu kB (inc. %8lu kB driver headroom)\n",
+ PAGES2KB(hard_limit), PAGES2KB(driver_pages));
+ } else {
+ len += sprintf(
+ page + len,
+ " ??? kB\n");
+ }
+
+ *eof = 1;
+ return len;
}
static struct notifier_block xenstore_notifier;
static int __init balloon_init(void)
{
- unsigned long pfn;
- struct page *page;
+ unsigned long pfn;
+ struct page *page;
- IPRINTK("Initialising balloon driver.\n");
+ IPRINTK("Initialising balloon driver.\n");
- current_pages = min(xen_start_info.nr_pages, max_pfn);
- target_pages = current_pages;
- balloon_low = 0;
- balloon_high = 0;
- driver_pages = 0UL;
- hard_limit = ~0UL;
+ current_pages = min(xen_start_info.nr_pages, max_pfn);
+ target_pages = current_pages;
+ balloon_low = 0;
+ balloon_high = 0;
+ driver_pages = 0UL;
+ hard_limit = ~0UL;
- init_timer(&balloon_timer);
- balloon_timer.data = 0;
- balloon_timer.function = balloon_alarm;
+ init_timer(&balloon_timer);
+ balloon_timer.data = 0;
+ balloon_timer.function = balloon_alarm;
- if ( (balloon_pde = create_xen_proc_entry("balloon", 0644)) == NULL )
- {
- WPRINTK("Unable to create /proc/xen/balloon.\n");
- return -1;
- }
-
- balloon_pde->read_proc = balloon_read;
- balloon_pde->write_proc = balloon_write;
+ if ((balloon_pde = create_xen_proc_entry("balloon", 0644)) == NULL) {
+ WPRINTK("Unable to create /proc/xen/balloon.\n");
+ return -1;
+ }
+
+ balloon_pde->read_proc = balloon_read;
+ balloon_pde->write_proc = balloon_write;
- /* Initialise the balloon with excess memory space. */
- for ( pfn = xen_start_info.nr_pages; pfn < max_pfn; pfn++ )
- {
- page = &mem_map[pfn];
- if ( !PageReserved(page) )
- balloon_append(page);
- }
-
- target_watch.callback = watch_target;
- xenstore_notifier.notifier_call = balloon_init_watcher;
-
- register_xenstore_notifier(&xenstore_notifier);
+ /* Initialise the balloon with excess memory space. */
+ for (pfn = xen_start_info.nr_pages; pfn < max_pfn; pfn++) {
+ page = &mem_map[pfn];
+ if (!PageReserved(page))
+ balloon_append(page);
+ }
+
+ target_watch.callback = watch_target;
+ xenstore_notifier.notifier_call = balloon_init_watcher;
+
+ register_xenstore_notifier(&xenstore_notifier);
- return 0;
+ return 0;
}
subsys_initcall(balloon_init);
void balloon_update_driver_allowance(long delta)
{
- unsigned long flags;
- balloon_lock(flags);
- driver_pages += delta; /* non-atomic update */
- balloon_unlock(flags);
+ unsigned long flags;
+ balloon_lock(flags);
+ driver_pages += delta; /* non-atomic update */
+ balloon_unlock(flags);
}
-void balloon_put_pages(unsigned long *mfn_list, unsigned long nr_mfns)
+struct page *balloon_alloc_empty_page_range(unsigned long nr_pages)
{
- unsigned long flags;
+ int f(pte_t *pte, struct page *pte_page,
+ unsigned long addr, void *data)
+ {
+ unsigned long mfn = pte_mfn(*pte);
+ set_pte(pte, __pte_ma(0));
+ phys_to_machine_mapping[__pa(addr) >> PAGE_SHIFT] =
+ INVALID_P2M_ENTRY;
+ BUG_ON(HYPERVISOR_dom_mem_op(
+ MEMOP_decrease_reservation, &mfn, 1, 0) != 1);
+ return 0;
+ }
+
+ unsigned long vstart, flags;
+ unsigned int order = get_order(nr_pages * PAGE_SIZE);
+
+ vstart = __get_free_pages(GFP_KERNEL, order);
+ if (vstart == 0)
+ return NULL;
+
+ scrub_pages(vstart, 1 << order);
+
+ balloon_lock(flags);
+ BUG_ON(generic_page_range(
+ &init_mm, vstart, PAGE_SIZE << order, f, NULL) != 0);
+ current_pages -= 1UL << order;
+ balloon_unlock(flags);
+
+ schedule_work(&balloon_worker);
+
+ flush_tlb_all();
- balloon_lock(flags);
- if ( HYPERVISOR_dom_mem_op(MEMOP_decrease_reservation,
- mfn_list, nr_mfns, 0) != nr_mfns )
- BUG();
- current_pages -= nr_mfns; /* non-atomic update */
- balloon_unlock(flags);
+ return virt_to_page(vstart);
+}
+
+void balloon_dealloc_empty_page_range(
+ struct page *page, unsigned long nr_pages)
+{
+ unsigned long i, flags;
+ unsigned int order = get_order(nr_pages * PAGE_SIZE);
+
+ balloon_lock(flags);
+ for (i = 0; i < (1UL << order); i++)
+ balloon_append(page + i);
+ balloon_unlock(flags);
- schedule_work(&balloon_worker);
+ schedule_work(&balloon_worker);
}
EXPORT_SYMBOL(balloon_update_driver_allowance);
-EXPORT_SYMBOL(balloon_put_pages);
+EXPORT_SYMBOL(balloon_alloc_empty_page_range);
+EXPORT_SYMBOL(balloon_dealloc_empty_page_range);
+
+/*
+ * Local variables:
+ * c-file-style: "linux"
+ * indent-tabs-mode: t
+ * c-indent-level: 8
+ * c-basic-offset: 8
+ * tab-width: 8
+ * End:
+ */
projects / xen.git / commitdiff