1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _MPX_HW_H
3 #define _MPX_HW_H
4
5 #include <assert.h>
6
7 /* Describe the MPX Hardware Layout in here */
8
9 #define NR_MPX_BOUNDS_REGISTERS 4
10
11 #ifdef __i386__
12
13 #define MPX_BOUNDS_TABLE_ENTRY_SIZE_BYTES 16 /* 4 * 32-bits */
14 #define MPX_BOUNDS_TABLE_SIZE_BYTES (1ULL << 14) /* 16k */
15 #define MPX_BOUNDS_DIR_ENTRY_SIZE_BYTES 4
16 #define MPX_BOUNDS_DIR_SIZE_BYTES (1ULL << 22) /* 4MB */
17
18 #define MPX_BOUNDS_TABLE_BOTTOM_BIT 2
19 #define MPX_BOUNDS_TABLE_TOP_BIT 11
20 #define MPX_BOUNDS_DIR_BOTTOM_BIT 12
21 #define MPX_BOUNDS_DIR_TOP_BIT 31
22
23 #else
24
25 /*
26 * Linear Address of "pointer" (LAp)
27 * 0 -> 2: ignored
28 * 3 -> 19: index in to bounds table
29 * 20 -> 47: index in to bounds directory
30 * 48 -> 63: ignored
31 */
32
33 #define MPX_BOUNDS_TABLE_ENTRY_SIZE_BYTES 32
34 #define MPX_BOUNDS_TABLE_SIZE_BYTES (1ULL << 22) /* 4MB */
35 #define MPX_BOUNDS_DIR_ENTRY_SIZE_BYTES 8
36 #define MPX_BOUNDS_DIR_SIZE_BYTES (1ULL << 31) /* 2GB */
37
38 #define MPX_BOUNDS_TABLE_BOTTOM_BIT 3
39 #define MPX_BOUNDS_TABLE_TOP_BIT 19
40 #define MPX_BOUNDS_DIR_BOTTOM_BIT 20
41 #define MPX_BOUNDS_DIR_TOP_BIT 47
42
43 #endif
44
45 #define MPX_BOUNDS_DIR_NR_ENTRIES \
46 (MPX_BOUNDS_DIR_SIZE_BYTES/MPX_BOUNDS_DIR_ENTRY_SIZE_BYTES)
47 #define MPX_BOUNDS_TABLE_NR_ENTRIES \
48 (MPX_BOUNDS_TABLE_SIZE_BYTES/MPX_BOUNDS_TABLE_ENTRY_SIZE_BYTES)
49
50 #define MPX_BOUNDS_TABLE_ENTRY_VALID_BIT 0x1
51
52 struct mpx_bd_entry {
53 union {
54 char x[MPX_BOUNDS_DIR_ENTRY_SIZE_BYTES];
55 void *contents[0];
56 };
57 } __attribute__((packed));
58
59 struct mpx_bt_entry {
60 union {
61 char x[MPX_BOUNDS_TABLE_ENTRY_SIZE_BYTES];
62 unsigned long contents[0];
63 };
64 } __attribute__((packed));
65
66 struct mpx_bounds_dir {
67 struct mpx_bd_entry entries[MPX_BOUNDS_DIR_NR_ENTRIES];
68 } __attribute__((packed));
69
70 struct mpx_bounds_table {
71 struct mpx_bt_entry entries[MPX_BOUNDS_TABLE_NR_ENTRIES];
72 } __attribute__((packed));
73
GET_BITS(unsigned long val,int bottombit,int topbit)74 static inline unsigned long GET_BITS(unsigned long val, int bottombit, int topbit)
75 {
76 int total_nr_bits = topbit - bottombit;
77 unsigned long mask = (1UL << total_nr_bits)-1;
78 return (val >> bottombit) & mask;
79 }
80
__vaddr_bounds_table_index(void * vaddr)81 static inline unsigned long __vaddr_bounds_table_index(void *vaddr)
82 {
83 return GET_BITS((unsigned long)vaddr, MPX_BOUNDS_TABLE_BOTTOM_BIT,
84 MPX_BOUNDS_TABLE_TOP_BIT);
85 }
86
__vaddr_bounds_directory_index(void * vaddr)87 static inline unsigned long __vaddr_bounds_directory_index(void *vaddr)
88 {
89 return GET_BITS((unsigned long)vaddr, MPX_BOUNDS_DIR_BOTTOM_BIT,
90 MPX_BOUNDS_DIR_TOP_BIT);
91 }
92
mpx_vaddr_to_bd_entry(void * vaddr,struct mpx_bounds_dir * bounds_dir)93 static inline struct mpx_bd_entry *mpx_vaddr_to_bd_entry(void *vaddr,
94 struct mpx_bounds_dir *bounds_dir)
95 {
96 unsigned long index = __vaddr_bounds_directory_index(vaddr);
97 return &bounds_dir->entries[index];
98 }
99
bd_entry_valid(struct mpx_bd_entry * bounds_dir_entry)100 static inline int bd_entry_valid(struct mpx_bd_entry *bounds_dir_entry)
101 {
102 unsigned long __bd_entry = (unsigned long)bounds_dir_entry->contents;
103 return (__bd_entry & MPX_BOUNDS_TABLE_ENTRY_VALID_BIT);
104 }
105
106 static inline struct mpx_bounds_table *
__bd_entry_to_bounds_table(struct mpx_bd_entry * bounds_dir_entry)107 __bd_entry_to_bounds_table(struct mpx_bd_entry *bounds_dir_entry)
108 {
109 unsigned long __bd_entry = (unsigned long)bounds_dir_entry->contents;
110 assert(__bd_entry & MPX_BOUNDS_TABLE_ENTRY_VALID_BIT);
111 __bd_entry &= ~MPX_BOUNDS_TABLE_ENTRY_VALID_BIT;
112 return (struct mpx_bounds_table *)__bd_entry;
113 }
114
115 static inline struct mpx_bt_entry *
mpx_vaddr_to_bt_entry(void * vaddr,struct mpx_bounds_dir * bounds_dir)116 mpx_vaddr_to_bt_entry(void *vaddr, struct mpx_bounds_dir *bounds_dir)
117 {
118 struct mpx_bd_entry *bde = mpx_vaddr_to_bd_entry(vaddr, bounds_dir);
119 struct mpx_bounds_table *bt = __bd_entry_to_bounds_table(bde);
120 unsigned long index = __vaddr_bounds_table_index(vaddr);
121 return &bt->entries[index];
122 }
123
124 #endif /* _MPX_HW_H */
125