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/thread.h"
  28 #include "qemu/queue.h"
  29 #ifdef CONFIG_TCG
  30 #include "tcg-target.h"
  31 #endif
  32 #ifndef CONFIG_USER_ONLY
  33 #include "exec/hwaddr.h"
  34 #endif
  35 #include "exec/memattrs.h"
  36
  37 #ifndef TARGET_LONG_BITS
  38 #error TARGET_LONG_BITS must be defined before including this header
  39 #endif
  40
  41 #define TARGET_LONG_SIZE (TARGET_LONG_BITS / 8)
  42
  43 /* target_ulong is the type of a virtual address */
  44 #if TARGET_LONG_SIZE == 4
  45 typedef int32_t target_long;
  46 typedef uint32_t target_ulong;
  47 #define TARGET_FMT_lx "%08x"
  48 #define TARGET_FMT_ld "%d"
  49 #define TARGET_FMT_lu "%u"
  50 #elif TARGET_LONG_SIZE == 8
  51 typedef int64_t target_long;
  52 typedef uint64_t target_ulong;
  53 #define TARGET_FMT_lx "%016" PRIx64
  54 #define TARGET_FMT_ld "%" PRId64
  55 #define TARGET_FMT_lu "%" PRIu64
  56 #else
  57 #error TARGET_LONG_SIZE undefined
  58 #endif
  59
  60 #if !defined(CONFIG_USER_ONLY) && defined(CONFIG_TCG)
  61 /* use a fully associative victim tlb of 8 entries */
  62 #define CPU_VTLB_SIZE 8
  63
  64 #if HOST_LONG_BITS == 32 && TARGET_LONG_BITS == 32
  65 #define CPU_TLB_ENTRY_BITS 4
  66 #else
  67 #define CPU_TLB_ENTRY_BITS 5
  68 #endif
  69
  70 /* TCG_TARGET_TLB_DISPLACEMENT_BITS is used in CPU_TLB_BITS to ensure that
  71  * the TLB is not unnecessarily small, but still small enough for the
  72  * TLB lookup instruction sequence used by the TCG target.
  73  *
  74  * TCG will have to generate an operand as large as the distance between
  75  * env and the tlb_table[NB_MMU_MODES - 1][0].addend.  For simplicity,
  76  * the TCG targets just round everything up to the next power of two, and
  77  * count bits.  This works because: 1) the size of each TLB is a largish
  78  * power of two, 2) and because the limit of the displacement is really close
  79  * to a power of two, 3) the offset of tlb_table[0][0] inside env is smaller
  80  * than the size of a TLB.
  81  *
  82  * For example, the maximum displacement 0xFFF0 on PPC and MIPS, but TCG
  83  * just says "the displacement is 16 bits".  TCG_TARGET_TLB_DISPLACEMENT_BITS
  84  * then ensures that tlb_table at least 0x8000 bytes large ("not unnecessarily
  85  * small": 2^15).  The operand then will come up smaller than 0xFFF0 without
  86  * any particular care, because the TLB for a single MMU mode is larger than
  87  * 0x10000-0xFFF0=16 bytes.  In the end, the maximum value of the operand
  88  * could be something like 0xC000 (the offset of the last TLB table) plus
  89  * 0x18 (the offset of the addend field in each TLB entry) plus the offset
  90  * of tlb_table inside env (which is non-trivial but not huge).
  91  */
  92 #define CPU_TLB_BITS                                             \
  93     MIN(8,                                                       \
  94         TCG_TARGET_TLB_DISPLACEMENT_BITS - CPU_TLB_ENTRY_BITS -  \
  95         (NB_MMU_MODES <= 1 ? 0 :                                 \
  96          NB_MMU_MODES <= 2 ? 1 :                                 \
  97          NB_MMU_MODES <= 4 ? 2 :                                 \
  98          NB_MMU_MODES <= 8 ? 3 : 4))
  99
 100 #define CPU_TLB_SIZE (1 << CPU_TLB_BITS)
 101
 102 typedef struct CPUTLBEntry {
 103     /* bit TARGET_LONG_BITS to TARGET_PAGE_BITS : virtual address
 104        bit TARGET_PAGE_BITS-1..4  : Nonzero for accesses that should not
 105                                     go directly to ram.
 106        bit 3                      : indicates that the entry is invalid
 107        bit 2..0                   : zero
 108     */
 109     union {
 110         struct {
 111             target_ulong addr_read;
 112             target_ulong addr_write;
 113             target_ulong addr_code;
 114             /* Addend to virtual address to get host address.  IO accesses
 115                use the corresponding iotlb value.  */
 116             uintptr_t addend;
 117         };
 118         /* padding to get a power of two size */
 119         uint8_t dummy[1 << CPU_TLB_ENTRY_BITS];
 120     };
 121 } CPUTLBEntry;
 122
 123 QEMU_BUILD_BUG_ON(sizeof(CPUTLBEntry) != (1 << CPU_TLB_ENTRY_BITS));
 124
 125 /* The IOTLB is not accessed directly inline by generated TCG code,
 126  * so the CPUIOTLBEntry layout is not as critical as that of the
 127  * CPUTLBEntry. (This is also why we don't want to combine the two
 128  * structs into one.)
 129  */
 130 typedef struct CPUIOTLBEntry {
 131     /*
 132      * @addr contains:
 133      *  - in the lower TARGET_PAGE_BITS, a physical section number
 134      *  - with the lower TARGET_PAGE_BITS masked off, an offset which
 135      *    must be added to the virtual address to obtain:
 136      *     + the ram_addr_t of the target RAM (if the physical section
 137      *       number is PHYS_SECTION_NOTDIRTY or PHYS_SECTION_ROM)
 138      *     + the offset within the target MemoryRegion (otherwise)
 139      */
 140     hwaddr addr;
 141     MemTxAttrs attrs;
 142 } CPUIOTLBEntry;
 143
 144 typedef struct CPUTLBDesc {
 145     /*
 146      * Describe a region covering all of the large pages allocated
 147      * into the tlb.  When any page within this region is flushed,
 148      * we must flush the entire tlb.  The region is matched if
 149      * (addr & large_page_mask) == large_page_addr.
 150      */
 151     target_ulong large_page_addr;
 152     target_ulong large_page_mask;
 153     /* The next index to use in the tlb victim table.  */
 154     size_t vindex;
 155 } CPUTLBDesc;
 156
 157 /*
 158  * Data elements that are shared between all MMU modes.
 159  */
 160 typedef struct CPUTLBCommon {
 161     /* Serialize updates to tlb_table and tlb_v_table, and others as noted. */
 162     QemuSpin lock;
 163     /*
 164      * Within dirty, for each bit N, modifications have been made to
 165      * mmu_idx N since the last time that mmu_idx was flushed.
 166      * Protected by tlb_c.lock.
 167      */
 168     uint16_t dirty;
 169     /*
 170      * Statistics.  These are not lock protected, but are read and
 171      * written atomically.  This allows the monitor to print a snapshot
 172      * of the stats without interfering with the cpu.
 173      */
 174     size_t full_flush_count;
 175     size_t part_flush_count;
 176     size_t elide_flush_count;
 177 } CPUTLBCommon;
 178
 179 /*
 180  * The meaning of each of the MMU modes is defined in the target code.
 181  * Note that NB_MMU_MODES is not yet defined; we can only reference it
 182  * within preprocessor defines that will be expanded later.
 183  */
 184 #define CPU_COMMON_TLB \
 185     CPUTLBCommon tlb_c;                                                 \
 186     CPUTLBDesc tlb_d[NB_MMU_MODES];                                     \
 187     CPUTLBEntry tlb_table[NB_MMU_MODES][CPU_TLB_SIZE];                  \
 188     CPUTLBEntry tlb_v_table[NB_MMU_MODES][CPU_VTLB_SIZE];               \
 189     CPUIOTLBEntry iotlb[NB_MMU_MODES][CPU_TLB_SIZE];                    \
 190     CPUIOTLBEntry iotlb_v[NB_MMU_MODES][CPU_VTLB_SIZE];
 191
 192 #else
 193
 194 #define CPU_COMMON_TLB
 195
 196 #endif
 197
 198
 199 #define CPU_COMMON                                                      \
 200     /* soft mmu support */                                              \
 201     CPU_COMMON_TLB                                                      \
 202
 203 #endif