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Diffstat (limited to 'arch/x86/include/asm/xen/page.h')
-rw-r--r--arch/x86/include/asm/xen/page.h31
1 files changed, 20 insertions, 11 deletions
diff --git a/arch/x86/include/asm/xen/page.h b/arch/x86/include/asm/xen/page.h
index 6aef9fbc09b7..b913915e8e63 100644
--- a/arch/x86/include/asm/xen/page.h
+++ b/arch/x86/include/asm/xen/page.h
@@ -79,30 +79,38 @@ static inline int phys_to_machine_mapping_valid(unsigned long pfn)
79 return get_phys_to_machine(pfn) != INVALID_P2M_ENTRY; 79 return get_phys_to_machine(pfn) != INVALID_P2M_ENTRY;
80} 80}
81 81
82static inline unsigned long mfn_to_pfn(unsigned long mfn) 82static inline unsigned long mfn_to_pfn_no_overrides(unsigned long mfn)
83{ 83{
84 unsigned long pfn; 84 unsigned long pfn;
85 int ret = 0; 85 int ret;
86 86
87 if (xen_feature(XENFEAT_auto_translated_physmap)) 87 if (xen_feature(XENFEAT_auto_translated_physmap))
88 return mfn; 88 return mfn;
89 89
90 if (unlikely(mfn >= machine_to_phys_nr)) { 90 if (unlikely(mfn >= machine_to_phys_nr))
91 pfn = ~0; 91 return ~0;
92 goto try_override; 92
93 }
94 pfn = 0;
95 /* 93 /*
96 * The array access can fail (e.g., device space beyond end of RAM). 94 * The array access can fail (e.g., device space beyond end of RAM).
97 * In such cases it doesn't matter what we return (we return garbage), 95 * In such cases it doesn't matter what we return (we return garbage),
98 * but we must handle the fault without crashing! 96 * but we must handle the fault without crashing!
99 */ 97 */
100 ret = __get_user(pfn, &machine_to_phys_mapping[mfn]); 98 ret = __get_user(pfn, &machine_to_phys_mapping[mfn]);
101try_override:
102 /* ret might be < 0 if there are no entries in the m2p for mfn */
103 if (ret < 0) 99 if (ret < 0)
104 pfn = ~0; 100 return ~0;
105 else if (get_phys_to_machine(pfn) != mfn) 101
102 return pfn;
103}
104
105static inline unsigned long mfn_to_pfn(unsigned long mfn)
106{
107 unsigned long pfn;
108
109 if (xen_feature(XENFEAT_auto_translated_physmap))
110 return mfn;
111
112 pfn = mfn_to_pfn_no_overrides(mfn);
113 if (get_phys_to_machine(pfn) != mfn) {
106 /* 114 /*
107 * If this appears to be a foreign mfn (because the pfn 115 * If this appears to be a foreign mfn (because the pfn
108 * doesn't map back to the mfn), then check the local override 116 * doesn't map back to the mfn), then check the local override
@@ -111,6 +119,7 @@ try_override:
111 * m2p_find_override_pfn returns ~0 if it doesn't find anything. 119 * m2p_find_override_pfn returns ~0 if it doesn't find anything.
112 */ 120 */
113 pfn = m2p_find_override_pfn(mfn, ~0); 121 pfn = m2p_find_override_pfn(mfn, ~0);
122 }
114 123
115 /* 124 /*
116 * pfn is ~0 if there are no entries in the m2p for mfn or if the 125 * pfn is ~0 if there are no entries in the m2p for mfn or if the