6 #include <xen/features.h>
7 #include <xen/interface/xen.h>
9 /**** MACHINE <-> PHYSICAL CONVERSION MACROS ****/
10 #define INVALID_P2M_ENTRY (~0UL)
11 #define FOREIGN_FRAME_BIT (1UL << (BITS_PER_LONG - 1))
12 #define FOREIGN_FRAME(m) ((m) | FOREIGN_FRAME_BIT)
14 /* Definitions for machine and pseudophysical addresses. */
16 typedef unsigned long long paddr_t;
17 typedef unsigned long long maddr_t;
19 typedef unsigned long paddr_t;
20 typedef unsigned long maddr_t;
25 extern unsigned long *phys_to_machine_mapping;
26 extern unsigned long max_mapnr;
28 #undef machine_to_phys_mapping
29 extern unsigned long *machine_to_phys_mapping;
30 extern unsigned long machine_to_phys_nr;
32 static inline unsigned long pfn_to_mfn(unsigned long pfn)
34 if (unlikely(xen_feature(XENFEAT_auto_translated_physmap)))
36 if (likely(max_mapnr))
37 BUG_ON(pfn >= max_mapnr);
38 return phys_to_machine_mapping[pfn] & ~FOREIGN_FRAME_BIT;
41 static inline int phys_to_machine_mapping_valid(unsigned long pfn)
43 if (unlikely(xen_feature(XENFEAT_auto_translated_physmap)))
45 if (likely(max_mapnr))
46 BUG_ON(pfn >= max_mapnr);
47 return (phys_to_machine_mapping[pfn] != INVALID_P2M_ENTRY);
50 static inline unsigned long mfn_to_pfn(unsigned long mfn)
54 if (unlikely(xen_feature(XENFEAT_auto_translated_physmap)))
57 if (unlikely(mfn >= machine_to_phys_nr))
60 /* The array access can fail (e.g., device space beyond end of RAM). */
62 "1: "_ASM_MOV" %1,%0\n"
64 ".section .fixup,\"ax\"\n"
65 "3: "_ASM_MOV" %2,%0\n"
70 : "m" (machine_to_phys_mapping[mfn]), "m" (max_mapnr) );
76 * We detect special mappings in one of two ways:
77 * 1. If the MFN is an I/O page then Xen will set the m2p entry
78 * to be outside our maximum possible pseudophys range.
79 * 2. If the MFN belongs to a different domain then we will certainly
80 * not have MFN in our p2m table. Conversely, if the page is ours,
81 * then we'll have p2m(m2p(MFN))==MFN.
82 * If we detect a special mapping then it doesn't have a 'struct page'.
83 * We force !pfn_valid() by returning an out-of-range pointer.
85 * NB. These checks require that, for any MFN that is not in our reservation,
86 * there is no PFN such that p2m(PFN) == MFN. Otherwise we can get confused if
87 * we are foreign-mapping the MFN, and the other domain as m2p(MFN) == PFN.
88 * Yikes! Various places must poke in INVALID_P2M_ENTRY for safety.
90 * NB2. When deliberately mapping foreign pages into the p2m table, you *must*
91 * use FOREIGN_FRAME(). This will cause pte_pfn() to choke on it, as we
92 * require. In all the cases we care about, the FOREIGN_FRAME bit is
93 * masked (e.g., pfn_to_mfn()) so behaviour there is correct.
95 static inline unsigned long mfn_to_local_pfn(phys_addr_t mfn)
97 unsigned long pfn = mfn_to_pfn(mfn);
98 if (likely(pfn < max_mapnr)
99 && likely(!xen_feature(XENFEAT_auto_translated_physmap))
100 && unlikely(phys_to_machine_mapping[pfn] != mfn))
101 return max_mapnr; /* force !pfn_valid() */
105 static inline void set_phys_to_machine(unsigned long pfn, unsigned long mfn)
107 if (likely(max_mapnr))
108 BUG_ON(pfn >= max_mapnr);
109 if (unlikely(xen_feature(XENFEAT_auto_translated_physmap))) {
110 BUG_ON(pfn != mfn && mfn != INVALID_P2M_ENTRY);
113 phys_to_machine_mapping[pfn] = mfn;
116 static inline maddr_t phys_to_machine(paddr_t phys)
118 maddr_t machine = pfn_to_mfn(phys >> PAGE_SHIFT);
119 machine = (machine << PAGE_SHIFT) | (phys & ~PAGE_MASK);
123 static inline paddr_t machine_to_phys(maddr_t machine)
125 paddr_t phys = mfn_to_pfn(machine >> PAGE_SHIFT);
126 phys = (phys << PAGE_SHIFT) | (machine & ~PAGE_MASK);
131 # include "maddr_32.h"
133 # include "maddr_64.h"
136 #else /* !CONFIG_XEN */
138 #define pfn_to_mfn(pfn) (pfn)
139 #define mfn_to_pfn(mfn) (mfn)
140 #define mfn_to_local_pfn(mfn) (mfn)
141 #define set_phys_to_machine(pfn, mfn) ((void)0)
142 #define phys_to_machine_mapping_valid(pfn) 1
143 #define phys_to_machine(phys) ((maddr_t)(phys))
144 #define machine_to_phys(mach) ((paddr_t)(mach))
145 #define pfn_pte_ma(pfn, prot) pfn_pte(pfn, prot)
146 #define __pte_ma(x) __pte(x)
148 #endif /* !CONFIG_XEN */
150 /* VIRT <-> MACHINE conversion */
151 #define virt_to_machine(v) phys_to_machine(__pa(v))
152 #define virt_to_mfn(v) pfn_to_mfn(__pa(v) >> PAGE_SHIFT)
153 #define mfn_to_virt(m) __va(mfn_to_pfn(m) << PAGE_SHIFT)
155 #endif /* _X86_MADDR_H */