xref: /openbmc/qemu/include/exec/cpu-defs.h (revision b91a0fa7)
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 NB_MMU_MODES
40 # error NB_MMU_MODES must be defined in cpu-param.h
41 #endif
42 #ifndef TARGET_PHYS_ADDR_SPACE_BITS
43 # error TARGET_PHYS_ADDR_SPACE_BITS must be defined in cpu-param.h
44 #endif
45 #ifndef TARGET_VIRT_ADDR_SPACE_BITS
46 # error TARGET_VIRT_ADDR_SPACE_BITS must be defined in cpu-param.h
47 #endif
48 #ifndef TARGET_PAGE_BITS
49 # ifdef TARGET_PAGE_BITS_VARY
50 #  ifndef TARGET_PAGE_BITS_MIN
51 #   error TARGET_PAGE_BITS_MIN must be defined in cpu-param.h
52 #  endif
53 # else
54 #  error TARGET_PAGE_BITS must be defined in cpu-param.h
55 # endif
56 #endif
57 
58 #define TARGET_LONG_SIZE (TARGET_LONG_BITS / 8)
59 
60 /* target_ulong is the type of a virtual address */
61 #if TARGET_LONG_SIZE == 4
62 typedef int32_t target_long;
63 typedef uint32_t target_ulong;
64 #define TARGET_FMT_lx "%08x"
65 #define TARGET_FMT_ld "%d"
66 #define TARGET_FMT_lu "%u"
67 #elif TARGET_LONG_SIZE == 8
68 typedef int64_t target_long;
69 typedef uint64_t target_ulong;
70 #define TARGET_FMT_lx "%016" PRIx64
71 #define TARGET_FMT_ld "%" PRId64
72 #define TARGET_FMT_lu "%" PRIu64
73 #else
74 #error TARGET_LONG_SIZE undefined
75 #endif
76 
77 #if !defined(CONFIG_USER_ONLY) && defined(CONFIG_TCG)
78 
79 /* use a fully associative victim tlb of 8 entries */
80 #define CPU_VTLB_SIZE 8
81 
82 #if HOST_LONG_BITS == 32 && TARGET_LONG_BITS == 32
83 #define CPU_TLB_ENTRY_BITS 4
84 #else
85 #define CPU_TLB_ENTRY_BITS 5
86 #endif
87 
88 #define CPU_TLB_DYN_MIN_BITS 6
89 #define CPU_TLB_DYN_DEFAULT_BITS 8
90 
91 # if HOST_LONG_BITS == 32
92 /* Make sure we do not require a double-word shift for the TLB load */
93 #  define CPU_TLB_DYN_MAX_BITS (32 - TARGET_PAGE_BITS)
94 # else /* HOST_LONG_BITS == 64 */
95 /*
96  * Assuming TARGET_PAGE_BITS==12, with 2**22 entries we can cover 2**(22+12) ==
97  * 2**34 == 16G of address space. This is roughly what one would expect a
98  * TLB to cover in a modern (as of 2018) x86_64 CPU. For instance, Intel
99  * Skylake's Level-2 STLB has 16 1G entries.
100  * Also, make sure we do not size the TLB past the guest's address space.
101  */
102 #  ifdef TARGET_PAGE_BITS_VARY
103 #   define CPU_TLB_DYN_MAX_BITS                                  \
104     MIN(22, TARGET_VIRT_ADDR_SPACE_BITS - TARGET_PAGE_BITS)
105 #  else
106 #   define CPU_TLB_DYN_MAX_BITS                                  \
107     MIN_CONST(22, TARGET_VIRT_ADDR_SPACE_BITS - TARGET_PAGE_BITS)
108 #  endif
109 # endif
110 
111 typedef struct CPUTLBEntry {
112     /* bit TARGET_LONG_BITS to TARGET_PAGE_BITS : virtual address
113        bit TARGET_PAGE_BITS-1..4  : Nonzero for accesses that should not
114                                     go directly to ram.
115        bit 3                      : indicates that the entry is invalid
116        bit 2..0                   : zero
117     */
118     union {
119         struct {
120             target_ulong addr_read;
121             target_ulong addr_write;
122             target_ulong addr_code;
123             /* Addend to virtual address to get host address.  IO accesses
124                use the corresponding iotlb value.  */
125             uintptr_t addend;
126         };
127         /* padding to get a power of two size */
128         uint8_t dummy[1 << CPU_TLB_ENTRY_BITS];
129     };
130 } CPUTLBEntry;
131 
132 QEMU_BUILD_BUG_ON(sizeof(CPUTLBEntry) != (1 << CPU_TLB_ENTRY_BITS));
133 
134 /* The IOTLB is not accessed directly inline by generated TCG code,
135  * so the CPUIOTLBEntry layout is not as critical as that of the
136  * CPUTLBEntry. (This is also why we don't want to combine the two
137  * structs into one.)
138  */
139 typedef struct CPUIOTLBEntry {
140     /*
141      * @addr contains:
142      *  - in the lower TARGET_PAGE_BITS, a physical section number
143      *  - with the lower TARGET_PAGE_BITS masked off, an offset which
144      *    must be added to the virtual address to obtain:
145      *     + the ram_addr_t of the target RAM (if the physical section
146      *       number is PHYS_SECTION_NOTDIRTY or PHYS_SECTION_ROM)
147      *     + the offset within the target MemoryRegion (otherwise)
148      */
149     hwaddr addr;
150     MemTxAttrs attrs;
151 } CPUIOTLBEntry;
152 
153 /*
154  * Data elements that are per MMU mode, minus the bits accessed by
155  * the TCG fast path.
156  */
157 typedef struct CPUTLBDesc {
158     /*
159      * Describe a region covering all of the large pages allocated
160      * into the tlb.  When any page within this region is flushed,
161      * we must flush the entire tlb.  The region is matched if
162      * (addr & large_page_mask) == large_page_addr.
163      */
164     target_ulong large_page_addr;
165     target_ulong large_page_mask;
166     /* host time (in ns) at the beginning of the time window */
167     int64_t window_begin_ns;
168     /* maximum number of entries observed in the window */
169     size_t window_max_entries;
170     size_t n_used_entries;
171     /* The next index to use in the tlb victim table.  */
172     size_t vindex;
173     /* The tlb victim table, in two parts.  */
174     CPUTLBEntry vtable[CPU_VTLB_SIZE];
175     CPUIOTLBEntry viotlb[CPU_VTLB_SIZE];
176     /* The iotlb.  */
177     CPUIOTLBEntry *iotlb;
178 } CPUTLBDesc;
179 
180 /*
181  * Data elements that are per MMU mode, accessed by the fast path.
182  * The structure is aligned to aid loading the pair with one insn.
183  */
184 typedef struct CPUTLBDescFast {
185     /* Contains (n_entries - 1) << CPU_TLB_ENTRY_BITS */
186     uintptr_t mask;
187     /* The array of tlb entries itself. */
188     CPUTLBEntry *table;
189 } CPUTLBDescFast QEMU_ALIGNED(2 * sizeof(void *));
190 
191 /*
192  * Data elements that are shared between all MMU modes.
193  */
194 typedef struct CPUTLBCommon {
195     /* Serialize updates to f.table and d.vtable, and others as noted. */
196     QemuSpin lock;
197     /*
198      * Within dirty, for each bit N, modifications have been made to
199      * mmu_idx N since the last time that mmu_idx was flushed.
200      * Protected by tlb_c.lock.
201      */
202     uint16_t dirty;
203     /*
204      * Statistics.  These are not lock protected, but are read and
205      * written atomically.  This allows the monitor to print a snapshot
206      * of the stats without interfering with the cpu.
207      */
208     size_t full_flush_count;
209     size_t part_flush_count;
210     size_t elide_flush_count;
211 } CPUTLBCommon;
212 
213 /*
214  * The entire softmmu tlb, for all MMU modes.
215  * The meaning of each of the MMU modes is defined in the target code.
216  * Since this is placed within CPUNegativeOffsetState, the smallest
217  * negative offsets are at the end of the struct.
218  */
219 
220 typedef struct CPUTLB {
221     CPUTLBCommon c;
222     CPUTLBDesc d[NB_MMU_MODES];
223     CPUTLBDescFast f[NB_MMU_MODES];
224 } CPUTLB;
225 
226 /* This will be used by TCG backends to compute offsets.  */
227 #define TLB_MASK_TABLE_OFS(IDX) \
228     ((int)offsetof(ArchCPU, neg.tlb.f[IDX]) - (int)offsetof(ArchCPU, env))
229 
230 #else
231 
232 typedef struct CPUTLB { } CPUTLB;
233 
234 #endif  /* !CONFIG_USER_ONLY && CONFIG_TCG */
235 
236 /*
237  * This structure must be placed in ArchCPU immediately
238  * before CPUArchState, as a field named "neg".
239  */
240 typedef struct CPUNegativeOffsetState {
241     CPUTLB tlb;
242     IcountDecr icount_decr;
243 } CPUNegativeOffsetState;
244 
245 #endif
246