include/exec/cpu-defs.h

   1 /*
   2  * common defines for all CPUs
   3  *
   4  * Copyright (c) 2003 Fabrice Bellard
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, see <http://www.gnu.org/licenses/>.
  18  */
  19 #ifndef CPU_DEFS_H
  20 #define CPU_DEFS_H
  21
  22 #ifndef NEED_CPU_H
  23 #error cpu.h included from common code
  24 #endif
  25
  26 #include "qemu/host-utils.h"
  27 #include "qemu/queue.h"
  28 #ifdef CONFIG_TCG
  29 #include "tcg-target.h"
  30 #endif
  31 #ifndef CONFIG_USER_ONLY
  32 #include "exec/hwaddr.h"
  33 #endif
  34 #include "exec/memattrs.h"
  35
  36 #ifndef TARGET_LONG_BITS
  37 #error TARGET_LONG_BITS must be defined before including this header
  38 #endif
  39
  40 #define TARGET_LONG_SIZE (TARGET_LONG_BITS / 8)
  41
  42 /* target_ulong is the type of a virtual address */
  43 #if TARGET_LONG_SIZE == 4
  44 typedef int32_t target_long;
  45 typedef uint32_t target_ulong;
  46 #define TARGET_FMT_lx "%08x"
  47 #define TARGET_FMT_ld "%d"
  48 #define TARGET_FMT_lu "%u"
  49 #elif TARGET_LONG_SIZE == 8
  50 typedef int64_t target_long;
  51 typedef uint64_t target_ulong;
  52 #define TARGET_FMT_lx "%016" PRIx64
  53 #define TARGET_FMT_ld "%" PRId64
  54 #define TARGET_FMT_lu "%" PRIu64
  55 #else
  56 #error TARGET_LONG_SIZE undefined
  57 #endif
  58
  59 #if !defined(CONFIG_USER_ONLY) && defined(CONFIG_TCG)
  60 /* use a fully associative victim tlb of 8 entries */
  61 #define CPU_VTLB_SIZE 8
  62
  63 #if HOST_LONG_BITS == 32 && TARGET_LONG_BITS == 32
  64 #define CPU_TLB_ENTRY_BITS 4
  65 #else
  66 #define CPU_TLB_ENTRY_BITS 5
  67 #endif
  68
  69 /* TCG_TARGET_TLB_DISPLACEMENT_BITS is used in CPU_TLB_BITS to ensure that
  70  * the TLB is not unnecessarily small, but still small enough for the
  71  * TLB lookup instruction sequence used by the TCG target.
  72  *
  73  * TCG will have to generate an operand as large as the distance between
  74  * env and the tlb_table[NB_MMU_MODES - 1][0].addend.  For simplicity,
  75  * the TCG targets just round everything up to the next power of two, and
  76  * count bits.  This works because: 1) the size of each TLB is a largish
  77  * power of two, 2) and because the limit of the displacement is really close
  78  * to a power of two, 3) the offset of tlb_table[0][0] inside env is smaller
  79  * than the size of a TLB.
  80  *
  81  * For example, the maximum displacement 0xFFF0 on PPC and MIPS, but TCG
  82  * just says "the displacement is 16 bits".  TCG_TARGET_TLB_DISPLACEMENT_BITS
  83  * then ensures that tlb_table at least 0x8000 bytes large ("not unnecessarily
  84  * small": 2^15).  The operand then will come up smaller than 0xFFF0 without
  85  * any particular care, because the TLB for a single MMU mode is larger than
  86  * 0x10000-0xFFF0=16 bytes.  In the end, the maximum value of the operand
  87  * could be something like 0xC000 (the offset of the last TLB table) plus
  88  * 0x18 (the offset of the addend field in each TLB entry) plus the offset
  89  * of tlb_table inside env (which is non-trivial but not huge).
  90  */
  91 #define CPU_TLB_BITS                                             \
  92     MIN(8,                                                       \
  93         TCG_TARGET_TLB_DISPLACEMENT_BITS - CPU_TLB_ENTRY_BITS -  \
  94         (NB_MMU_MODES <= 1 ? 0 :                                 \
  95          NB_MMU_MODES <= 2 ? 1 :                                 \
  96          NB_MMU_MODES <= 4 ? 2 :                                 \
  97          NB_MMU_MODES <= 8 ? 3 : 4))
  98
  99 #define CPU_TLB_SIZE (1 << CPU_TLB_BITS)
 100
 101 typedef struct CPUTLBEntry {
 102     /* bit TARGET_LONG_BITS to TARGET_PAGE_BITS : virtual address
 103        bit TARGET_PAGE_BITS-1..4  : Nonzero for accesses that should not
 104                                     go directly to ram.
 105        bit 3                      : indicates that the entry is invalid
 106        bit 2..0                   : zero
 107     */
 108     union {
 109         struct {
 110             target_ulong addr_read;
 111             target_ulong addr_write;
 112             target_ulong addr_code;
 113             /* Addend to virtual address to get host address.  IO accesses
 114                use the corresponding iotlb value.  */
 115             uintptr_t addend;
 116         };
 117         /* padding to get a power of two size */
 118         uint8_t dummy[1 << CPU_TLB_ENTRY_BITS];
 119     };
 120 } CPUTLBEntry;
 121
 122 QEMU_BUILD_BUG_ON(sizeof(CPUTLBEntry) != (1 << CPU_TLB_ENTRY_BITS));
 123
 124 /* The IOTLB is not accessed directly inline by generated TCG code,
 125  * so the CPUIOTLBEntry layout is not as critical as that of the
 126  * CPUTLBEntry. (This is also why we don't want to combine the two
 127  * structs into one.)
 128  */
 129 typedef struct CPUIOTLBEntry {
 130     /*
 131      * @addr contains:
 132      *  - in the lower TARGET_PAGE_BITS, a physical section number
 133      *  - with the lower TARGET_PAGE_BITS masked off, an offset which
 134      *    must be added to the virtual address to obtain:
 135      *     + the ram_addr_t of the target RAM (if the physical section
 136      *       number is PHYS_SECTION_NOTDIRTY or PHYS_SECTION_ROM)
 137      *     + the offset within the target MemoryRegion (otherwise)
 138      */
 139     hwaddr addr;
 140     MemTxAttrs attrs;
 141 } CPUIOTLBEntry;
 142
 143 #define CPU_COMMON_TLB \
 144     /* The meaning of the MMU modes is defined in the target code. */   \
 145     CPUTLBEntry tlb_table[NB_MMU_MODES][CPU_TLB_SIZE];                  \
 146     CPUTLBEntry tlb_v_table[NB_MMU_MODES][CPU_VTLB_SIZE];               \
 147     CPUIOTLBEntry iotlb[NB_MMU_MODES][CPU_TLB_SIZE];                    \
 148     CPUIOTLBEntry iotlb_v[NB_MMU_MODES][CPU_VTLB_SIZE];                 \
 149     size_t tlb_flush_count;                                             \
 150     target_ulong tlb_flush_addr;                                        \
 151     target_ulong tlb_flush_mask;                                        \
 152     target_ulong vtlb_index;                                            \
 153
 154 #else
 155
 156 #define CPU_COMMON_TLB
 157
 158 #endif
 159
 160
 161 #define CPU_COMMON                                                      \
 162     /* soft mmu support */                                              \
 163     CPU_COMMON_TLB                                                      \
 164
 165 #endif