xref: /openbmc/qemu/include/exec/cpu-defs.h (revision 2df1eb27)
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 2.1 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 #ifndef CONFIG_USER_ONLY
29 #include "exec/hwaddr.h"
30 #endif
31 #include "exec/memattrs.h"
32 #include "hw/core/cpu.h"
33 
34 #include "cpu-param.h"
35 
36 #ifndef TARGET_LONG_BITS
37 # error TARGET_LONG_BITS must be defined in cpu-param.h
38 #endif
39 #ifndef TARGET_PHYS_ADDR_SPACE_BITS
40 # error TARGET_PHYS_ADDR_SPACE_BITS must be defined in cpu-param.h
41 #endif
42 #ifndef TARGET_VIRT_ADDR_SPACE_BITS
43 # error TARGET_VIRT_ADDR_SPACE_BITS must be defined in cpu-param.h
44 #endif
45 #ifndef TARGET_PAGE_BITS
46 # ifdef TARGET_PAGE_BITS_VARY
47 #  ifndef TARGET_PAGE_BITS_MIN
48 #   error TARGET_PAGE_BITS_MIN must be defined in cpu-param.h
49 #  endif
50 # else
51 #  error TARGET_PAGE_BITS must be defined in cpu-param.h
52 # endif
53 #endif
54 
55 #include "exec/target_long.h"
56 
57 #if defined(CONFIG_SOFTMMU) && defined(CONFIG_TCG)
58 #define CPU_TLB_DYN_MIN_BITS 6
59 #define CPU_TLB_DYN_DEFAULT_BITS 8
60 
61 # if HOST_LONG_BITS == 32
62 /* Make sure we do not require a double-word shift for the TLB load */
63 #  define CPU_TLB_DYN_MAX_BITS (32 - TARGET_PAGE_BITS)
64 # else /* HOST_LONG_BITS == 64 */
65 /*
66  * Assuming TARGET_PAGE_BITS==12, with 2**22 entries we can cover 2**(22+12) ==
67  * 2**34 == 16G of address space. This is roughly what one would expect a
68  * TLB to cover in a modern (as of 2018) x86_64 CPU. For instance, Intel
69  * Skylake's Level-2 STLB has 16 1G entries.
70  * Also, make sure we do not size the TLB past the guest's address space.
71  */
72 #  ifdef TARGET_PAGE_BITS_VARY
73 #   define CPU_TLB_DYN_MAX_BITS                                  \
74     MIN(22, TARGET_VIRT_ADDR_SPACE_BITS - TARGET_PAGE_BITS)
75 #  else
76 #   define CPU_TLB_DYN_MAX_BITS                                  \
77     MIN_CONST(22, TARGET_VIRT_ADDR_SPACE_BITS - TARGET_PAGE_BITS)
78 #  endif
79 # endif
80 
81 #endif /* CONFIG_SOFTMMU && CONFIG_TCG */
82 
83 #endif
84