[XenARM] [PATCH 12/14] arm: implement get/put page functions

[Jae-Min Ryu <jm77.ryu@xxxxxxxxxxx>]

arm: implement get/put page functions

 xen/arch/arm/xen/mm.c |  61 
+++++++++++++++++++++++++++++++++++++++++++++++++++++++------
 1 files changed, 55 insertions(+), 6 deletions(-)

Signed-off-by: Jaemin Ryu <jm77.ryu@xxxxxxxxxxx>

diff -r c3e7333eefc3 xen/arch/arm/xen/mm.c
--- a/xen/arch/arm/xen/mm.c     Sun Feb 12 15:04:24 2012 +0900
+++ b/xen/arch/arm/xen/mm.c     Sun Feb 12 15:13:09 2012 +0900
@@ -73,29 +73,78 @@ void memguard_unguard_range(void *p, uns
 
 void put_page(struct page_info *page)
 {
-       NOT_YET();
+        u32 nx, x, y = page->count_info;
+
+        do {
+                x  = y;
+                nx = x - 1;
+        } while ( unlikely((y = cmpxchg(&page->count_info, x, nx)) != x) );
+
+        if ( unlikely((nx & PGC_count_mask) == 0) ) {
+                free_domheap_page(page);
+        }
+
 }
 
 struct domain *page_get_owner_and_reference(struct page_info *page)
 {
-       NOT_YET();
+        unsigned long x, y = page->count_info;
+
+        do {
+                x = y;
+                if(unlikely(((x + 2) & PGC_count_mask) <= 2) )
+                        return NULL;
+        } while((y = cmpxchg(&page->count_info,x,x+1)) != x);
+
+        return page_get_owner(page);
+
 }
 
 int get_page(struct page_info *page, struct domain *domain)
 {
-       NOT_YET();
+        struct domain *owner = page_get_owner_and_reference(page);
 
-       return 0;
+        if (likely(owner == domain))
+                return 1;
+
+        if (owner != domain)
+                put_page(page);
+
+        return 0;
 }
 
 void share_xen_page_with_guest(struct page_info *page, struct domain *d, int 
readonly)
 {
-       NOT_YET();
+        if(page_get_owner(page) == d)
+                return;
+
+        set_gpfn_from_mfn(page_to_mfn(page), INVALID_M2P_ENTRY);
+
+        spin_lock(&d->page_alloc_lock);
+
+        /* The incremented type count pins as writable or read-only. */
+        page->u.inuse.type_info  = (readonly ? PGT_none : PGT_writable_page);
+        page->u.inuse.type_info |= PGT_validated | 1;
+
+        page_set_owner(page, d);
+        wmb(); /* install valid domain ptr before updating refcnt. */
+        ASSERT((page->count_info & ~PGC_xen_heap) == 0);
+
+        if (!d->is_dying) {
+                page->count_info |= PGC_allocated | 1;
+
+                if ( unlikely(d->xenheap_pages++ == 0) )
+                        get_knownalive_domain(d);
+
+                page_list_add_tail(page, &d->xenpage_list);
+        }
+
+        spin_unlock(&d->page_alloc_lock);
 }
 
 void share_xen_page_with_privileged_guests(struct page_info *page, int 
readonly)
 {
-       NOT_YET();
+        share_xen_page_with_guest(page, dom_xen, readonly);
 }
 
 static int pin_page_table(u32 mfn, struct domain *d)

Attachment: patch12.diff
Description: Binary data

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