LXR linux/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
  52struct mpx_bd_entry {
  53        union {
  54                char x[MPX_BOUNDS_DIR_ENTRY_SIZE_BYTES];
  55                void *contents[0];
  56        };
  57} __attribute__((packed));
  58
  59struct mpx_bt_entry {
  60        union {
  61                char x[MPX_BOUNDS_TABLE_ENTRY_SIZE_BYTES];
  62                unsigned long contents[0];
  63        };
  64} __attribute__((packed));
  65
  66struct mpx_bounds_dir {
  67        struct mpx_bd_entry entries[MPX_BOUNDS_DIR_NR_ENTRIES];
  68} __attribute__((packed));
  69
  70struct mpx_bounds_table {
  71        struct mpx_bt_entry entries[MPX_BOUNDS_TABLE_NR_ENTRIES];
  72} __attribute__((packed));
  73
  74static 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
  81static 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
  87static 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
  93static 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
 100static 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
 106static 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
 115static inline struct mpx_bt_entry *
 116mpx_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