1 files changed, 213 insertions, 0 deletions
diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h
new file mode 100644
index 00000000..c34f96c2
--- /dev/null
+++ b/arch/x86/include/asm/xen/page.h
@@ -0,0 +1,213 @@
+#ifndef _ASM_X86_XEN_PAGE_H
+#define _ASM_X86_XEN_PAGE_H
+
+#include <linux/kernel.h>
+#include <linux/types.h>
+#include <linux/spinlock.h>
+#include <linux/pfn.h>
+#include <linux/mm.h>
+
+#include <asm/uaccess.h>
+#include <asm/page.h>
+#include <asm/pgtable.h>
+
+#include <xen/interface/xen.h>
+#include <xen/grant_table.h>
+#include <xen/features.h>
+
+/* Xen machine address */
+typedef struct xmaddr {
+	phys_addr_t maddr;
+} xmaddr_t;
+
+/* Xen pseudo-physical address */
+typedef struct xpaddr {
+	phys_addr_t paddr;
+} xpaddr_t;
+
+#define XMADDR(x)	((xmaddr_t) { .maddr = (x) })
+#define XPADDR(x)	((xpaddr_t) { .paddr = (x) })
+
+/**** MACHINE <-> PHYSICAL CONVERSION MACROS ****/
+#define INVALID_P2M_ENTRY	(~0UL)
+#define FOREIGN_FRAME_BIT	(1UL<<(BITS_PER_LONG-1))
+#define IDENTITY_FRAME_BIT	(1UL<<(BITS_PER_LONG-2))
+#define FOREIGN_FRAME(m)	((m) | FOREIGN_FRAME_BIT)
+#define IDENTITY_FRAME(m)	((m) | IDENTITY_FRAME_BIT)
+
+/* Maximum amount of memory we can handle in a domain in pages */
+#define MAX_DOMAIN_PAGES						\
+    ((unsigned long)((u64)CONFIG_XEN_MAX_DOMAIN_MEMORY * 1024 * 1024 * 1024 / PAGE_SIZE))
+
+extern unsigned long *machine_to_phys_mapping;
+extern unsigned long  machine_to_phys_nr;
+
+extern unsigned long get_phys_to_machine(unsigned long pfn);
+extern bool set_phys_to_machine(unsigned long pfn, unsigned long mfn);
+extern bool __set_phys_to_machine(unsigned long pfn, unsigned long mfn);
+extern unsigned long set_phys_range_identity(unsigned long pfn_s,
+					     unsigned long pfn_e);
+
+extern int m2p_add_override(unsigned long mfn, struct page *page,
+			    struct gnttab_map_grant_ref *kmap_op);
+extern int m2p_remove_override(struct page *page, bool clear_pte);
+extern struct page *m2p_find_override(unsigned long mfn);
+extern unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn);
+
+static inline unsigned long pfn_to_mfn(unsigned long pfn)
+{
+	unsigned long mfn;
+
+	if (xen_feature(XENFEAT_auto_translated_physmap))
+		return pfn;
+
+	mfn = get_phys_to_machine(pfn);
+
+	if (mfn != INVALID_P2M_ENTRY)
+		mfn &= ~(FOREIGN_FRAME_BIT | IDENTITY_FRAME_BIT);
+
+	return mfn;
+}
+
+static inline int phys_to_machine_mapping_valid(unsigned long pfn)
+{
+	if (xen_feature(XENFEAT_auto_translated_physmap))
+		return 1;
+
+	return get_phys_to_machine(pfn) != INVALID_P2M_ENTRY;
+}
+
+static inline unsigned long mfn_to_pfn(unsigned long mfn)
+{
+	unsigned long pfn;
+	int ret = 0;
+
+	if (xen_feature(XENFEAT_auto_translated_physmap))
+		return mfn;
+
+	if (unlikely(mfn >= machine_to_phys_nr)) {
+		pfn = ~0;
+		goto try_override;
+	}
+	pfn = 0;
+	/*
+	 * The array access can fail (e.g., device space beyond end of RAM).
+	 * In such cases it doesn't matter what we return (we return garbage),
+	 * but we must handle the fault without crashing!
+	 */
+	ret = __get_user(pfn, &machine_to_phys_mapping[mfn]);
+try_override:
+	/* ret might be < 0 if there are no entries in the m2p for mfn */
+	if (ret < 0)
+		pfn = ~0;
+	else if (get_phys_to_machine(pfn) != mfn)
+		/*
+		 * If this appears to be a foreign mfn (because the pfn
+		 * doesn't map back to the mfn), then check the local override
+		 * table to see if there's a better pfn to use.
+		 *
+		 * m2p_find_override_pfn returns ~0 if it doesn't find anything.
+		 */
+		pfn = m2p_find_override_pfn(mfn, ~0);
+
+	/* 
+	 * pfn is ~0 if there are no entries in the m2p for mfn or if the
+	 * entry doesn't map back to the mfn and m2p_override doesn't have a
+	 * valid entry for it.
+	 */
+	if (pfn == ~0 &&
+			get_phys_to_machine(mfn) == IDENTITY_FRAME(mfn))
+		pfn = mfn;
+
+	return pfn;
+}
+
+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);
+}
+
+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);
+}
+
+/*
+ * We detect special mappings in one of two ways:
+ *  1. If the MFN is an I/O page then Xen will set the m2p entry
+ *     to be outside our maximum possible pseudophys range.
+ *  2. If the MFN belongs to a different domain then we will certainly
+ *     not have MFN in our p2m table. Conversely, if the page is ours,
+ *     then we'll have p2m(m2p(MFN))==MFN.
+ * If we detect a special mapping then it doesn't have a 'struct page'.
+ * We force !pfn_valid() by returning an out-of-range pointer.
+ *
+ * NB. These checks require that, for any MFN that is not in our reservation,
+ * there is no PFN such that p2m(PFN) == MFN. Otherwise we can get confused if
+ * we are foreign-mapping the MFN, and the other domain as m2p(MFN) == PFN.
+ * Yikes! Various places must poke in INVALID_P2M_ENTRY for safety.
+ *
+ * NB2. When deliberately mapping foreign pages into the p2m table, you *must*
+ *      use FOREIGN_FRAME(). This will cause pte_pfn() to choke on it, as we
+ *      require. In all the cases we care about, the FOREIGN_FRAME bit is
+ *      masked (e.g., pfn_to_mfn()) so behaviour there is correct.
+ */
+static inline unsigned long mfn_to_local_pfn(unsigned long mfn)
+{
+	unsigned long pfn = mfn_to_pfn(mfn);
+	if (get_phys_to_machine(pfn) != mfn)
+		return -1; /* force !pfn_valid() */
+	return pfn;
+}
+
+/* VIRT <-> MACHINE conversion */
+#define virt_to_machine(v)	(phys_to_machine(XPADDR(__pa(v))))
+#define virt_to_pfn(v)          (PFN_DOWN(__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))
+
+static inline unsigned long pte_mfn(pte_t pte)
+{
+	return (pte.pte & PTE_PFN_MASK) >> PAGE_SHIFT;
+}
+
+static inline pte_t mfn_pte(unsigned long page_nr, pgprot_t pgprot)
+{
+	pte_t pte;
+
+	pte.pte = ((phys_addr_t)page_nr << PAGE_SHIFT) |
+			massage_pgprot(pgprot);
+
+	return pte;
+}
+
+static inline pteval_t pte_val_ma(pte_t pte)
+{
+	return pte.pte;
+}
+
+static inline pte_t __pte_ma(pteval_t x)
+{
+	return (pte_t) { .pte = x };
+}
+
+#define pmd_val_ma(v) ((v).pmd)
+#ifdef __PAGETABLE_PUD_FOLDED
+#define pud_val_ma(v) ((v).pgd.pgd)
+#else
+#define pud_val_ma(v) ((v).pud)
+#endif
+#define __pmd_ma(x)	((pmd_t) { (x) } )
+
+#define pgd_val_ma(x)	((x).pgd)
+
+void xen_set_domain_pte(pte_t *ptep, pte_t pteval, unsigned domid);
+
+xmaddr_t arbitrary_virt_to_machine(void *address);
+unsigned long arbitrary_virt_to_mfn(void *vaddr);
+void make_lowmem_page_readonly(void *vaddr);
+void make_lowmem_page_readwrite(void *vaddr);
+
+#endif /* _ASM_X86_XEN_PAGE_H */