1 files changed, 178 insertions, 42 deletions

diff --git a/include/xen/grant_table.h b/include/xen/grant_table.h
index 694dcaf266e6..69ac6d80a006 100644
--- a/include/xen/grant_table.h
+++ b/include/xen/grant_table.h
@@ -45,8 +45,17 @@
 #include <asm/xen/hypervisor.h>
 
 #include <xen/features.h>
+#include <xen/page.h>
+#include <linux/mm_types.h>
+#include <linux/page-flags.h>
+#include <linux/kernel.h>
 
-#define GNTTAB_RESERVED_XENSTORE 1
+/*
+ * Technically there's no reliably invalid grant reference or grant handle,
+ * so pick the value that is the most unlikely one to be observed valid.
+ */
+#define INVALID_GRANT_REF          ((grant_ref_t)-1)
+#define INVALID_GRANT_HANDLE       ((grant_handle_t)-1)
 
 /* NR_GRANT_FRAMES must be less than or equal to that configured in Xen */
 #define NR_GRANT_FRAMES 4
@@ -58,63 +67,74 @@ struct gnttab_free_callback {
 	u16 count;
 };
 
+struct gntab_unmap_queue_data;
+
+typedef void (*gnttab_unmap_refs_done)(int result, struct gntab_unmap_queue_data *data);
+
+struct gntab_unmap_queue_data
+{
+	struct delayed_work	gnttab_work;
+	void *data;
+	gnttab_unmap_refs_done	done;
+	struct gnttab_unmap_grant_ref *unmap_ops;
+	struct gnttab_unmap_grant_ref *kunmap_ops;
+	struct page **pages;
+	unsigned int count;
+	unsigned int age;
+};
+
 int gnttab_init(void);
 int gnttab_suspend(void);
 int gnttab_resume(void);
 
 int gnttab_grant_foreign_access(domid_t domid, unsigned long frame,
 				int readonly);
-int gnttab_grant_foreign_access_subpage(domid_t domid, unsigned long frame,
-					int flags, unsigned page_off,
-					unsigned length);
-int gnttab_grant_foreign_access_trans(domid_t domid, int flags,
-				      domid_t trans_domid,
-				      grant_ref_t trans_gref);
-
-/*
- * Are sub-page grants available on this version of Xen?  Returns true if they
- * are, and false if they're not.
- */
-bool gnttab_subpage_grants_available(void);
-
-/*
- * Are transitive grants available on this version of Xen?  Returns true if they
- * are, and false if they're not.
- */
-bool gnttab_trans_grants_available(void);
 
 /*
  * End access through the given grant reference, iff the grant entry is no
  * longer in use.  Return 1 if the grant entry was freed, 0 if it is still in
  * use.
  */
-int gnttab_end_foreign_access_ref(grant_ref_t ref, int readonly);
+int gnttab_end_foreign_access_ref(grant_ref_t ref);
 
 /*
  * Eventually end access through the given grant reference, and once that
  * access has been ended, free the given page too.  Access will be ended
  * immediately iff the grant entry is not in use, otherwise it will happen
- * some time later.  page may be 0, in which case no freeing will occur.
+ * some time later.  page may be NULL, in which case no freeing will occur.
+ * Note that the granted page might still be accessed (read or write) by the
+ * other side after gnttab_end_foreign_access() returns, so even if page was
+ * specified as NULL it is not allowed to just reuse the page for other
+ * purposes immediately. gnttab_end_foreign_access() will take an additional
+ * reference to the granted page in this case, which is dropped only after
+ * the grant is no longer in use.
+ * This requires that multi page allocations for areas subject to
+ * gnttab_end_foreign_access() are done via alloc_pages_exact() (and freeing
+ * via free_pages_exact()) in order to avoid high order pages.
  */
-void gnttab_end_foreign_access(grant_ref_t ref, int readonly,
-			       unsigned long page);
-
-int gnttab_grant_foreign_transfer(domid_t domid, unsigned long pfn);
-
-unsigned long gnttab_end_foreign_transfer_ref(grant_ref_t ref);
-unsigned long gnttab_end_foreign_transfer(grant_ref_t ref);
+void gnttab_end_foreign_access(grant_ref_t ref, struct page *page);
 
-int gnttab_query_foreign_access(grant_ref_t ref);
+/*
+ * End access through the given grant reference, iff the grant entry is
+ * no longer in use.  In case of success ending foreign access, the
+ * grant reference is deallocated.
+ * Return 1 if the grant entry was freed, 0 if it is still in use.
+ */
+int gnttab_try_end_foreign_access(grant_ref_t ref);
 
 /*
  * operations on reserved batches of grant references
  */
 int gnttab_alloc_grant_references(u16 count, grant_ref_t *pprivate_head);
 
+int gnttab_alloc_grant_reference_seq(unsigned int count, grant_ref_t *first);
+
 void gnttab_free_grant_reference(grant_ref_t ref);
 
 void gnttab_free_grant_references(grant_ref_t head);
 
+void gnttab_free_grant_reference_seq(grant_ref_t head, unsigned int count);
+
 int gnttab_empty_grant_references(const grant_ref_t *pprivate_head);
 
 int gnttab_claim_grant_reference(grant_ref_t *pprivate_head);
@@ -128,16 +148,15 @@ void gnttab_cancel_free_callback(struct gnttab_free_callback *callback);
 
 void gnttab_grant_foreign_access_ref(grant_ref_t ref, domid_t domid,
 				     unsigned long frame, int readonly);
-int gnttab_grant_foreign_access_subpage_ref(grant_ref_t ref, domid_t domid,
-					    unsigned long frame, int flags,
-					    unsigned page_off,
-					    unsigned length);
-int gnttab_grant_foreign_access_trans_ref(grant_ref_t ref, domid_t domid,
-					  int flags, domid_t trans_domid,
-					  grant_ref_t trans_gref);
 
-void gnttab_grant_foreign_transfer_ref(grant_ref_t, domid_t domid,
-				       unsigned long pfn);
+/* Give access to the first 4K of the page */
+static inline void gnttab_page_grant_foreign_access_ref_one(
+	grant_ref_t ref, domid_t domid,
+	struct page *page, int readonly)
+{
+	gnttab_grant_foreign_access_ref(ref, domid, xen_page_to_gfn(page),
+					readonly);
+}
 
 static inline void
 gnttab_set_map_op(struct gnttab_map_grant_ref *map, phys_addr_t addr,
@@ -145,7 +164,7 @@ gnttab_set_map_op(struct gnttab_map_grant_ref *map, phys_addr_t addr,
 {
 	if (flags & GNTMAP_contains_pte)
 		map->host_addr = addr;
-	else if (xen_feature(XENFEAT_auto_translated_physmap))
+	else if (!xen_pv_domain())
 		map->host_addr = __pa(addr);
 	else
 		map->host_addr = addr;
@@ -153,6 +172,7 @@ gnttab_set_map_op(struct gnttab_map_grant_ref *map, phys_addr_t addr,
 	map->flags = flags;
 	map->ref = ref;
 	map->dom = domid;
+	map->status = 1; /* arbitrary positive value */
 }
 
 static inline void
@@ -161,7 +181,7 @@ gnttab_set_unmap_op(struct gnttab_unmap_grant_ref *unmap, phys_addr_t addr,
 {
 	if (flags & GNTMAP_contains_pte)
 		unmap->host_addr = addr;
-	else if (xen_feature(XENFEAT_auto_translated_physmap))
+	else if (!xen_pv_domain())
 		unmap->host_addr = __pa(addr);
 	else
 		unmap->host_addr = addr;
@@ -170,6 +190,7 @@ gnttab_set_unmap_op(struct gnttab_unmap_grant_ref *unmap, phys_addr_t addr,
 	unmap->dev_bus_addr = 0;
 }
 
+int arch_gnttab_init(unsigned long nr_shared, unsigned long nr_status);
 int arch_gnttab_map_shared(xen_pfn_t *frames, unsigned long nr_gframes,
 			   unsigned long max_nr_gframes,
 			   void **__shared);
@@ -178,17 +199,68 @@ int arch_gnttab_map_status(uint64_t *frames, unsigned long nr_gframes,
 			   grant_status_t **__shared);
 void arch_gnttab_unmap(void *shared, unsigned long nr_gframes);
 
-extern unsigned long xen_hvm_resume_frames;
+struct grant_frames {
+	xen_pfn_t *pfn;
+	unsigned int count;
+	void *vaddr;
+};
+extern struct grant_frames xen_auto_xlat_grant_frames;
 unsigned int gnttab_max_grant_frames(void);
+int gnttab_setup_auto_xlat_frames(phys_addr_t addr);
+void gnttab_free_auto_xlat_frames(void);
 
 #define gnttab_map_vaddr(map) ((void *)(map.host_virt_addr))
 
+int gnttab_alloc_pages(int nr_pages, struct page **pages);
+void gnttab_free_pages(int nr_pages, struct page **pages);
+
+struct gnttab_page_cache {
+	spinlock_t		lock;
+#ifdef CONFIG_XEN_UNPOPULATED_ALLOC
+	struct page		*pages;
+#else
+	struct list_head	pages;
+#endif
+	unsigned int		num_pages;
+};
+
+void gnttab_page_cache_init(struct gnttab_page_cache *cache);
+int gnttab_page_cache_get(struct gnttab_page_cache *cache, struct page **page);
+void gnttab_page_cache_put(struct gnttab_page_cache *cache, struct page **page,
+			   unsigned int num);
+void gnttab_page_cache_shrink(struct gnttab_page_cache *cache,
+			      unsigned int num);
+
+#ifdef CONFIG_XEN_GRANT_DMA_ALLOC
+struct gnttab_dma_alloc_args {
+	/* Device for which DMA memory will be/was allocated. */
+	struct device *dev;
+	/* If set then DMA buffer is coherent and write-combine otherwise. */
+	bool coherent;
+
+	int nr_pages;
+	struct page **pages;
+	xen_pfn_t *frames;
+	void *vaddr;
+	dma_addr_t dev_bus_addr;
+};
+
+int gnttab_dma_alloc_pages(struct gnttab_dma_alloc_args *args);
+int gnttab_dma_free_pages(struct gnttab_dma_alloc_args *args);
+#endif
+
+int gnttab_pages_set_private(int nr_pages, struct page **pages);
+void gnttab_pages_clear_private(int nr_pages, struct page **pages);
+
 int gnttab_map_refs(struct gnttab_map_grant_ref *map_ops,
 		    struct gnttab_map_grant_ref *kmap_ops,
 		    struct page **pages, unsigned int count);
 int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
-		      struct gnttab_map_grant_ref *kunmap_ops,
+		      struct gnttab_unmap_grant_ref *kunmap_ops,
 		      struct page **pages, unsigned int count);
+void gnttab_unmap_refs_async(struct gntab_unmap_queue_data* item);
+int gnttab_unmap_refs_sync(struct gntab_unmap_queue_data *item);
+
 
 /* Perform a batch of grant map/copy operations. Retry every batch slot
  * for which the hypervisor returns GNTST_eagain. This is typically due
@@ -202,4 +274,68 @@ int gnttab_unmap_refs(struct gnttab_unmap_grant_ref *unmap_ops,
 void gnttab_batch_map(struct gnttab_map_grant_ref *batch, unsigned count);
 void gnttab_batch_copy(struct gnttab_copy *batch, unsigned count);
 
+
+struct xen_page_foreign {
+	domid_t domid;
+	grant_ref_t gref;
+};
+
+static inline struct xen_page_foreign *xen_page_foreign(struct page *page)
+{
+	if (!PageForeign(page))
+		return NULL;
+#if BITS_PER_LONG < 64
+	return (struct xen_page_foreign *)page->private;
+#else
+	BUILD_BUG_ON(sizeof(struct xen_page_foreign) > BITS_PER_LONG);
+	return (struct xen_page_foreign *)&page->private;
+#endif
+}
+
+/* Split Linux page in chunk of the size of the grant and call fn
+ *
+ * Parameters of fn:
+ *	gfn: guest frame number
+ *	offset: offset in the grant
+ *	len: length of the data in the grant.
+ *	data: internal information
+ */
+typedef void (*xen_grant_fn_t)(unsigned long gfn, unsigned int offset,
+			       unsigned int len, void *data);
+
+void gnttab_foreach_grant_in_range(struct page *page,
+				   unsigned int offset,
+				   unsigned int len,
+				   xen_grant_fn_t fn,
+				   void *data);
+
+/* Helper to get to call fn only on the first "grant chunk" */
+static inline void gnttab_for_one_grant(struct page *page, unsigned int offset,
+					unsigned len, xen_grant_fn_t fn,
+					void *data)
+{
+	/* The first request is limited to the size of one grant */
+	len = min_t(unsigned int, XEN_PAGE_SIZE - (offset & ~XEN_PAGE_MASK),
+		    len);
+
+	gnttab_foreach_grant_in_range(page, offset, len, fn, data);
+}
+
+/* Get @nr_grefs grants from an array of page and call fn for each grant */
+void gnttab_foreach_grant(struct page **pages,
+			  unsigned int nr_grefs,
+			  xen_grant_fn_t fn,
+			  void *data);
+
+/* Get the number of grant in a specified region
+ *
+ * start: Offset from the beginning of the first page
+ * len: total length of data (can cross multiple page)
+ */
+static inline unsigned int gnttab_count_grant(unsigned int start,
+					      unsigned int len)
+{
+	return XEN_PFN_UP(xen_offset_in_page(start) + len);
+}
+
 #endif /* __ASM_GNTTAB_H__ */