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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] adds get_page/put_page to XEN/IA64
ChangeSet 1.1709.1.4, 2005/06/14 11:33:23-06:00, djm@xxxxxxxxxxxxxxx
adds get_page/put_page to XEN/IA64
Signed-off-by Kevin Tian <Kevin.tian@xxxxxxxxx>
mm.h | 113 ++++++++++++++++++++++++++++++++++++-------------------------------
1 files changed, 62 insertions(+), 51 deletions(-)
diff -Nru a/xen/include/asm-ia64/mm.h b/xen/include/asm-ia64/mm.h
--- a/xen/include/asm-ia64/mm.h 2005-06-19 14:03:52 -04:00
+++ b/xen/include/asm-ia64/mm.h 2005-06-19 14:03:52 -04:00
@@ -27,43 +27,12 @@
/*
* Per-page-frame information.
+ *
+ * Every architecture must ensure the following:
+ * 1. 'struct pfn_info' contains a 'struct list_head list'.
+ * 2. Provide a PFN_ORDER() macro for accessing the order of a free page.
*/
-
-//FIXME: This can go away when common/dom0_ops.c is fully arch-independent
-#if 0
-struct pfn_info
-{
- /* Each frame can be threaded onto a doubly-linked list. */
- struct list_head list;
- /* Context-dependent fields follow... */
- union {
-
- /* Page is in use by a domain. */
- struct {
- /* Owner of this page. */
- struct domain *domain;
- /* Reference count and various PGC_xxx flags and fields. */
- u32 count_info;
- /* Type reference count and various PGT_xxx flags and fields. */
- u32 type_info;
- } inuse;
-
- /* Page is on a free list. */
- struct {
- /* Mask of possibly-tainted TLBs. */
- unsigned long cpu_mask;
- /* Must be at same offset as 'u.inuse.count_flags'. */
- u32 __unavailable;
- /* Order-size of the free chunk this page is the head of. */
- u8 order;
- } free;
-
- } u;
-
- /* Timestamp from 'TLB clock', used to reduce need for safety flushes. */
- u32 tlbflush_timestamp;
-};
-#endif
+#define PFN_ORDER(_pfn) ((_pfn)->u.free.order)
struct page
{
@@ -82,7 +51,7 @@
/* Page is in use by a domain. */
struct {
/* Owner of this page. */
- u64 _domain;
+ u32 _domain;
/* Type reference count and various PGT_xxx flags and fields. */
u32 type_info;
} inuse;
@@ -104,37 +73,49 @@
#define set_page_count(p,v) atomic_set(&(p)->_count, v - 1)
-//FIXME: These can go away when common/dom0_ops.c is fully arch-independent
- /* The following page types are MUTUALLY EXCLUSIVE. */
+/* Still small set of flags defined by far on IA-64 */
+/* The following page types are MUTUALLY EXCLUSIVE. */
#define PGT_none (0<<29) /* no special uses of this page */
#define PGT_l1_page_table (1<<29) /* using this page as an L1 page table? */
#define PGT_l2_page_table (2<<29) /* using this page as an L2 page table? */
#define PGT_l3_page_table (3<<29) /* using this page as an L3 page table? */
#define PGT_l4_page_table (4<<29) /* using this page as an L4 page table? */
-#define PGT_gdt_page (5<<29) /* using this page in a GDT? */
-#define PGT_ldt_page (6<<29) /* using this page in an LDT? */
-#define PGT_writeable_page (7<<29) /* has writable mappings of this page? */
-#define PGT_type_mask (7<<29) /* Bits 29-31. */
+#define PGT_writeable_page (5<<29) /* has writable mappings of this page? */
+#define PGT_type_mask (5<<29) /* Bits 29-31. */
+
/* Has this page been validated for use as its current type? */
#define _PGT_validated 28
#define PGT_validated (1<<_PGT_validated)
- /* 28-bit count of uses of this frame as its current type. */
-#define PGT_count_mask ((1<<28)-1)
+/* Owning guest has pinned this page to its current type? */
+#define _PGT_pinned 27
+#define PGT_pinned (1U<<_PGT_pinned)
+
+/* 27-bit count of uses of this frame as its current type. */
+#define PGT_count_mask ((1U<<27)-1)
/* Cleared when the owning guest 'frees' this page. */
#define _PGC_allocated 31
#define PGC_allocated (1U<<_PGC_allocated)
-#define PFN_ORDER(_pfn) ((_pfn)->u.free.order)
+/* Set when the page is used as a page table */
+#define _PGC_page_table 30
+#define PGC_page_table (1U<<_PGC_page_table)
+/* 30-bit count of references to this frame. */
+#define PGC_count_mask ((1U<<30)-1)
#define IS_XEN_HEAP_FRAME(_pfn) ((page_to_phys(_pfn) < xenheap_phys_end) \
&& (page_to_phys(_pfn) >= xen_pstart))
-#define pickle_domptr(_d) ((u64)(_d))
-#define unpickle_domptr(_d) ((struct domain*)(_d))
+static inline struct domain *unpickle_domptr(u32 _d)
+{ return (_d == 0) ? NULL : __va(_d); }
+static inline u32 pickle_domptr(struct domain *_d)
+{ return (_d == NULL) ? 0 : (u32)__pa(_d); }
#define page_get_owner(_p) (unpickle_domptr((_p)->u.inuse._domain))
#define page_set_owner(_p, _d) ((_p)->u.inuse._domain = pickle_domptr(_d))
+/* Dummy now */
+#define SHARE_PFN_WITH_DOMAIN(_pfn, _dom) do { } while (0)
+
extern struct pfn_info *frame_table;
extern unsigned long frame_table_size;
extern struct list_head free_list;
@@ -151,15 +132,45 @@
static inline void put_page(struct pfn_info *page)
{
- dummy();
-}
+ 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);
+}
+
+/* count_info and ownership are checked atomically. */
static inline int get_page(struct pfn_info *page,
struct domain *domain)
{
- dummy();
+ u64 x, nx, y = *((u64*)&page->count_info);
+ u32 _domain = pickle_domptr(domain);
+
+ do {
+ x = y;
+ nx = x + 1;
+ if (unlikely((x & PGC_count_mask) == 0) || /* Not allocated? */
+ unlikely((nx & PGC_count_mask) == 0) || /* Count overflow? */
+ unlikely((x >> 32) != _domain)) { /* Wrong owner? */
+ DPRINTK("Error pfn %lx: rd=%p, od=%p, caf=%08x, taf=%08x\n",
+ page_to_pfn(page), domain, unpickle_domptr(d),
+ x, page->u.inuse.typeinfo);
+ return 0;
+ }
+ }
+ while(unlikely(y = cmpxchg(&page->count_info, x, nx)) != x);
+
+ return 1;
}
+
+/* No type info now */
+#define put_page_and_type(page) put_page((page))
+#define get_page_and_type(page, domain, type) get_page((page))
#define set_machinetophys(_mfn, _pfn) do { } while(0);
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