4 files changed, 82 insertions, 36 deletions

diff --git a/kernel/arch/arm/include/asm/xen/events.h b/kernel/arch/arm/include/asm/xen/events.h
index 8b1f37bfe..71e473d05 100644
--- a/kernel/arch/arm/include/asm/xen/events.h
+++ b/kernel/arch/arm/include/asm/xen/events.h
@@ -20,4 +20,10 @@ static inline int xen_irqs_disabled(struct pt_regs *regs)
 							    atomic64_t,	\
 							    counter), (val))
 
+/* Rebind event channel is supported by default */
+static inline bool xen_support_evtchn_rebind(void)
+{
+	return true;
+}
+
 #endif /* _ASM_ARM_XEN_EVENTS_H */
diff --git a/kernel/arch/arm/include/asm/xen/hypervisor.h b/kernel/arch/arm/include/asm/xen/hypervisor.h
index 1317ee40f..95251512e 100644
--- a/kernel/arch/arm/include/asm/xen/hypervisor.h
+++ b/kernel/arch/arm/include/asm/xen/hypervisor.h
@@ -1,6 +1,8 @@
 #ifndef _ASM_ARM_XEN_HYPERVISOR_H
 #define _ASM_ARM_XEN_HYPERVISOR_H
 
+#include <linux/init.h>
+
 extern struct shared_info *HYPERVISOR_shared_info;
 extern struct start_info *xen_start_info;
 
@@ -18,4 +20,20 @@ static inline enum paravirt_lazy_mode paravirt_get_lazy_mode(void)
 
 extern struct dma_map_ops *xen_dma_ops;
 
+#ifdef CONFIG_XEN
+void __init xen_early_init(void);
+#else
+static inline void xen_early_init(void) { return; }
+#endif
+
+#ifdef CONFIG_HOTPLUG_CPU
+static inline void xen_arch_register_cpu(int num)
+{
+}
+
+static inline void xen_arch_unregister_cpu(int num)
+{
+}
+#endif
+
 #endif /* _ASM_ARM_XEN_HYPERVISOR_H */
diff --git a/kernel/arch/arm/include/asm/xen/page-coherent.h b/kernel/arch/arm/include/asm/xen/page-coherent.h
index efd562412..9408a994c 100644
--- a/kernel/arch/arm/include/asm/xen/page-coherent.h
+++ b/kernel/arch/arm/include/asm/xen/page-coherent.h
@@ -35,11 +35,22 @@ static inline void xen_dma_map_page(struct device *hwdev, struct page *page,
 	     dma_addr_t dev_addr, unsigned long offset, size_t size,
 	     enum dma_data_direction dir, struct dma_attrs *attrs)
 {
-	bool local = PFN_DOWN(dev_addr) == page_to_pfn(page);
-	/* Dom0 is mapped 1:1, so if pfn == mfn the page is local otherwise
-	 * is a foreign page grant-mapped in dom0. If the page is local we
-	 * can safely call the native dma_ops function, otherwise we call
-	 * the xen specific function. */
+	unsigned long page_pfn = page_to_xen_pfn(page);
+	unsigned long dev_pfn = XEN_PFN_DOWN(dev_addr);
+	unsigned long compound_pages =
+		(1<<compound_order(page)) * XEN_PFN_PER_PAGE;
+	bool local = (page_pfn <= dev_pfn) &&
+		(dev_pfn - page_pfn < compound_pages);
+
+	/*
+	 * Dom0 is mapped 1:1, while the Linux page can span across
+	 * multiple Xen pages, it's not possible for it to contain a
+	 * mix of local and foreign Xen pages. So if the first xen_pfn
+	 * == mfn the page is local otherwise it's a foreign page
+	 * grant-mapped in dom0. If the page is local we can safely
+	 * call the native dma_ops function, otherwise we call the xen
+	 * specific function.
+	 */
 	if (local)
 		__generic_dma_ops(hwdev)->map_page(hwdev, page, offset, size, dir, attrs);
 	else
@@ -51,10 +62,14 @@ static inline void xen_dma_unmap_page(struct device *hwdev, dma_addr_t handle,
 		struct dma_attrs *attrs)
 {
 	unsigned long pfn = PFN_DOWN(handle);
-	/* Dom0 is mapped 1:1, so calling pfn_valid on a foreign mfn will
-	 * always return false. If the page is local we can safely call the
-	 * native dma_ops function, otherwise we call the xen specific
-	 * function. */
+	/*
+	 * Dom0 is mapped 1:1, while the Linux page can be spanned accross
+	 * multiple Xen page, it's not possible to have a mix of local and
+	 * foreign Xen page. Dom0 is mapped 1:1, so calling pfn_valid on a
+	 * foreign mfn will always return false. If the page is local we can
+	 * safely call the native dma_ops function, otherwise we call the xen
+	 * specific function.
+	 */
 	if (pfn_valid(pfn)) {
 		if (__generic_dma_ops(hwdev)->unmap_page)
 			__generic_dma_ops(hwdev)->unmap_page(hwdev, handle, size, dir, attrs);
diff --git a/kernel/arch/arm/include/asm/xen/page.h b/kernel/arch/arm/include/asm/xen/page.h
index 0b579b2f4..415dbc6e4 100644
--- a/kernel/arch/arm/include/asm/xen/page.h
+++ b/kernel/arch/arm/include/asm/xen/page.h
@@ -12,10 +12,6 @@
 #include <xen/interface/grant_table.h>
 
 #define phys_to_machine_mapping_valid(pfn) (1)
-#define mfn_to_virt(m)			(__va(mfn_to_pfn(m) << PAGE_SHIFT))
-
-#define pte_mfn	    pte_pfn
-#define mfn_pte	    pfn_pte
 
 /* Xen machine address */
 typedef struct xmaddr {
@@ -32,10 +28,33 @@ typedef struct xpaddr {
 
 #define INVALID_P2M_ENTRY      (~0UL)
 
+/*
+ * The pseudo-physical frame (pfn) used in all the helpers is always based
+ * on Xen page granularity (i.e 4KB).
+ *
+ * A Linux page may be split across multiple non-contiguous Xen page so we
+ * have to keep track with frame based on 4KB page granularity.
+ *
+ * PV drivers should never make a direct usage of those helpers (particularly
+ * pfn_to_gfn and gfn_to_pfn).
+ */
+
 unsigned long __pfn_to_mfn(unsigned long pfn);
 extern struct rb_root phys_to_mach;
 
-static inline unsigned long pfn_to_mfn(unsigned long pfn)
+/* Pseudo-physical <-> Guest conversion */
+static inline unsigned long pfn_to_gfn(unsigned long pfn)
+{
+	return pfn;
+}
+
+static inline unsigned long gfn_to_pfn(unsigned long gfn)
+{
+	return gfn;
+}
+
+/* Pseudo-physical <-> BUS conversion */
+static inline unsigned long pfn_to_bfn(unsigned long pfn)
 {
 	unsigned long mfn;
 
@@ -48,33 +67,21 @@ static inline unsigned long pfn_to_mfn(unsigned long pfn)
 	return pfn;
 }
 
-static inline unsigned long mfn_to_pfn(unsigned long mfn)
+static inline unsigned long bfn_to_pfn(unsigned long bfn)
 {
-	return mfn;
+	return bfn;
 }
 
-#define mfn_to_local_pfn(mfn) mfn_to_pfn(mfn)
-
-static inline xmaddr_t phys_to_machine(xpaddr_t phys)
-{
-	unsigned offset = phys.paddr & ~PAGE_MASK;
-	return XMADDR(PFN_PHYS(pfn_to_mfn(PFN_DOWN(phys.paddr))) | offset);
-}
+#define bfn_to_local_pfn(bfn)	bfn_to_pfn(bfn)
 
-static inline xpaddr_t machine_to_phys(xmaddr_t machine)
-{
-	unsigned offset = machine.maddr & ~PAGE_MASK;
-	return XPADDR(PFN_PHYS(mfn_to_pfn(PFN_DOWN(machine.maddr))) | offset);
-}
-/* VIRT <-> MACHINE conversion */
-#define virt_to_machine(v)	(phys_to_machine(XPADDR(__pa(v))))
-#define virt_to_mfn(v)		(pfn_to_mfn(virt_to_pfn(v)))
-#define mfn_to_virt(m)		(__va(mfn_to_pfn(m) << PAGE_SHIFT))
+/* VIRT <-> GUEST conversion */
+#define virt_to_gfn(v)		(pfn_to_gfn(virt_to_phys(v) >> XEN_PAGE_SHIFT))
+#define gfn_to_virt(m)		(__va(gfn_to_pfn(m) << XEN_PAGE_SHIFT))
 
+/* Only used in PV code. But ARM guests are always HVM. */
 static inline xmaddr_t arbitrary_virt_to_machine(void *vaddr)
 {
-	/* TODO: assuming it is mapped in the kernel 1:1 */
-	return virt_to_machine(vaddr);
+	BUG();
 }
 
 /* TODO: this shouldn't be here but it is because the frontend drivers
@@ -108,8 +115,8 @@ static inline bool set_phys_to_machine(unsigned long pfn, unsigned long mfn)
 #define xen_unmap(cookie) iounmap((cookie))
 
 bool xen_arch_need_swiotlb(struct device *dev,
-			   unsigned long pfn,
-			   unsigned long mfn);
+			   phys_addr_t phys,
+			   dma_addr_t dev_addr);
 unsigned long xen_get_swiotlb_free_pages(unsigned int order);
 
 #endif /* _ASM_ARM_XEN_PAGE_H */