Merge tag 'iwlwifi-next-for-kalle-2014-12-30' of https://git.kernel.org/pub/scm/linux...

[cascardo/linux.git] / arch / x86 / include / asm / xen / page.h

diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h
index f58ef6c..5eea099 100644 (file)
--- a/arch/x86/include/asm/xen/page.h
+++ b/arch/x86/include/asm/xen/page.h
@@ -41,10 +41,12 @@ typedef struct xpaddr {
 
 extern unsigned long *machine_to_phys_mapping;
 extern unsigned long  machine_to_phys_nr;
+extern unsigned long *xen_p2m_addr;
+extern unsigned long  xen_p2m_size;
+extern unsigned long  xen_max_p2m_pfn;
 
 extern unsigned long get_phys_to_machine(unsigned long pfn);
 extern bool set_phys_to_machine(unsigned long pfn, unsigned long mfn);
-extern bool __init early_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);
@@ -52,17 +54,52 @@ extern unsigned long set_phys_range_identity(unsigned long pfn_s,
 extern int set_foreign_p2m_mapping(struct gnttab_map_grant_ref *map_ops,
                                   struct gnttab_map_grant_ref *kmap_ops,
                                   struct page **pages, unsigned int count);
-extern int m2p_add_override(unsigned long mfn, struct page *page,
-                           struct gnttab_map_grant_ref *kmap_op);
 extern int clear_foreign_p2m_mapping(struct gnttab_unmap_grant_ref *unmap_ops,
                                     struct gnttab_map_grant_ref *kmap_ops,
                                     struct page **pages, unsigned int count);
-extern int m2p_remove_override(struct page *page,
-                              struct gnttab_map_grant_ref *kmap_op,
-                              unsigned long mfn);
-extern struct page *m2p_find_override(unsigned long mfn);
 extern unsigned long m2p_find_override_pfn(unsigned long mfn, unsigned long pfn);
 
+/*
+ * Helper functions to write or read unsigned long values to/from
+ * memory, when the access may fault.
+ */
+static inline int xen_safe_write_ulong(unsigned long *addr, unsigned long val)
+{
+       return __put_user(val, (unsigned long __user *)addr);
+}
+
+static inline int xen_safe_read_ulong(unsigned long *addr, unsigned long *val)
+{
+       return __get_user(*val, (unsigned long __user *)addr);
+}
+
+/*
+ * When to use pfn_to_mfn(), __pfn_to_mfn() or get_phys_to_machine():
+ * - pfn_to_mfn() returns either INVALID_P2M_ENTRY or the mfn. No indicator
+ *   bits (identity or foreign) are set.
+ * - __pfn_to_mfn() returns the found entry of the p2m table. A possibly set
+ *   identity or foreign indicator will be still set. __pfn_to_mfn() is
+ *   encapsulating get_phys_to_machine() which is called in special cases only.
+ * - get_phys_to_machine() is to be called by __pfn_to_mfn() only in special
+ *   cases needing an extended handling.
+ */
+static inline unsigned long __pfn_to_mfn(unsigned long pfn)
+{
+       unsigned long mfn;
+
+       if (pfn < xen_p2m_size)
+               mfn = xen_p2m_addr[pfn];
+       else if (unlikely(pfn < xen_max_p2m_pfn))
+               return get_phys_to_machine(pfn);
+       else
+               return IDENTITY_FRAME(pfn);
+
+       if (unlikely(mfn == INVALID_P2M_ENTRY))
+               return get_phys_to_machine(pfn);
+
+       return mfn;
+}
+
 static inline unsigned long pfn_to_mfn(unsigned long pfn)
 {
        unsigned long mfn;
@@ -70,7 +107,7 @@ static inline unsigned long pfn_to_mfn(unsigned long pfn)
        if (xen_feature(XENFEAT_auto_translated_physmap))
                return pfn;
 
-       mfn = get_phys_to_machine(pfn);
+       mfn = __pfn_to_mfn(pfn);
 
        if (mfn != INVALID_P2M_ENTRY)
                mfn &= ~(FOREIGN_FRAME_BIT | IDENTITY_FRAME_BIT);
@@ -83,7 +120,7 @@ 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;
+       return __pfn_to_mfn(pfn) != INVALID_P2M_ENTRY;
 }
 
 static inline unsigned long mfn_to_pfn_no_overrides(unsigned long mfn)
@@ -102,7 +139,7 @@ static inline unsigned long mfn_to_pfn_no_overrides(unsigned long mfn)
         * 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]);
+       ret = xen_safe_read_ulong(&machine_to_phys_mapping[mfn], &pfn);
        if (ret < 0)
                return ~0;
 
@@ -117,7 +154,7 @@ static inline unsigned long mfn_to_pfn(unsigned long mfn)
                return mfn;
 
        pfn = mfn_to_pfn_no_overrides(mfn);
-       if (get_phys_to_machine(pfn) != mfn) {
+       if (__pfn_to_mfn(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
@@ -133,8 +170,7 @@ static inline unsigned long mfn_to_pfn(unsigned long mfn)
         * 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))
+       if (pfn == ~0 && __pfn_to_mfn(mfn) == IDENTITY_FRAME(mfn))
                pfn = mfn;
 
        return pfn;
@@ -180,7 +216,7 @@ static inline unsigned long mfn_to_local_pfn(unsigned long mfn)
                return mfn;
 
        pfn = mfn_to_pfn(mfn);
-       if (get_phys_to_machine(pfn) != mfn)
+       if (__pfn_to_mfn(pfn) != mfn)
                return -1; /* force !pfn_valid() */
        return pfn;
 }