tools/testing/selftests/x86/mpx-hw.h

   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[1];
  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[1];
  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
  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
  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
  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
  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
 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 *
 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 *
 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 */