xref: /openbmc/qemu/include/exec/cpu-defs.h (revision c63ca4ff)
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 #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 #include "hw/core/cpu.h"
36 
37 #include "cpu-param.h"
38 
39 #ifndef TARGET_LONG_BITS
40 # error TARGET_LONG_BITS must be defined in cpu-param.h
41 #endif
42 #ifndef NB_MMU_MODES
43 # error NB_MMU_MODES must be defined in cpu-param.h
44 #endif
45 #ifndef TARGET_PHYS_ADDR_SPACE_BITS
46 # error TARGET_PHYS_ADDR_SPACE_BITS must be defined in cpu-param.h
47 #endif
48 #ifndef TARGET_VIRT_ADDR_SPACE_BITS
49 # error TARGET_VIRT_ADDR_SPACE_BITS must be defined in cpu-param.h
50 #endif
51 #ifndef TARGET_PAGE_BITS
52 # ifdef TARGET_PAGE_BITS_VARY
53 #  ifndef TARGET_PAGE_BITS_MIN
54 #   error TARGET_PAGE_BITS_MIN must be defined in cpu-param.h
55 #  endif
56 # else
57 #  error TARGET_PAGE_BITS must be defined in cpu-param.h
58 # endif
59 #endif
60 
61 #define TARGET_LONG_SIZE (TARGET_LONG_BITS / 8)
62 
63 /* target_ulong is the type of a virtual address */
64 #if TARGET_LONG_SIZE == 4
65 typedef int32_t target_long;
66 typedef uint32_t target_ulong;
67 #define TARGET_FMT_lx "%08x"
68 #define TARGET_FMT_ld "%d"
69 #define TARGET_FMT_lu "%u"
70 #elif TARGET_LONG_SIZE == 8
71 typedef int64_t target_long;
72 typedef uint64_t target_ulong;
73 #define TARGET_FMT_lx "%016" PRIx64
74 #define TARGET_FMT_ld "%" PRId64
75 #define TARGET_FMT_lu "%" PRIu64
76 #else
77 #error TARGET_LONG_SIZE undefined
78 #endif
79 
80 #if !defined(CONFIG_USER_ONLY) && defined(CONFIG_TCG)
81 
82 /* use a fully associative victim tlb of 8 entries */
83 #define CPU_VTLB_SIZE 8
84 
85 #if HOST_LONG_BITS == 32 && TARGET_LONG_BITS == 32
86 #define CPU_TLB_ENTRY_BITS 4
87 #else
88 #define CPU_TLB_ENTRY_BITS 5
89 #endif
90 
91 #define CPU_TLB_DYN_MIN_BITS 6
92 #define CPU_TLB_DYN_DEFAULT_BITS 8
93 
94 # if HOST_LONG_BITS == 32
95 /* Make sure we do not require a double-word shift for the TLB load */
96 #  define CPU_TLB_DYN_MAX_BITS (32 - TARGET_PAGE_BITS)
97 # else /* HOST_LONG_BITS == 64 */
98 /*
99  * Assuming TARGET_PAGE_BITS==12, with 2**22 entries we can cover 2**(22+12) ==
100  * 2**34 == 16G of address space. This is roughly what one would expect a
101  * TLB to cover in a modern (as of 2018) x86_64 CPU. For instance, Intel
102  * Skylake's Level-2 STLB has 16 1G entries.
103  * Also, make sure we do not size the TLB past the guest's address space.
104  */
105 #  ifdef TARGET_PAGE_BITS_VARY
106 #   define CPU_TLB_DYN_MAX_BITS                                  \
107     MIN(22, TARGET_VIRT_ADDR_SPACE_BITS - TARGET_PAGE_BITS)
108 #  else
109 #   define CPU_TLB_DYN_MAX_BITS                                  \
110     MIN_CONST(22, TARGET_VIRT_ADDR_SPACE_BITS - TARGET_PAGE_BITS)
111 #  endif
112 # endif
113 
114 typedef struct CPUTLBEntry {
115     /* bit TARGET_LONG_BITS to TARGET_PAGE_BITS : virtual address
116        bit TARGET_PAGE_BITS-1..4  : Nonzero for accesses that should not
117                                     go directly to ram.
118        bit 3                      : indicates that the entry is invalid
119        bit 2..0                   : zero
120     */
121     union {
122         struct {
123             target_ulong addr_read;
124             target_ulong addr_write;
125             target_ulong addr_code;
126             /* Addend to virtual address to get host address.  IO accesses
127                use the corresponding iotlb value.  */
128             uintptr_t addend;
129         };
130         /* padding to get a power of two size */
131         uint8_t dummy[1 << CPU_TLB_ENTRY_BITS];
132     };
133 } CPUTLBEntry;
134 
135 QEMU_BUILD_BUG_ON(sizeof(CPUTLBEntry) != (1 << CPU_TLB_ENTRY_BITS));
136 
137 /* The IOTLB is not accessed directly inline by generated TCG code,
138  * so the CPUIOTLBEntry layout is not as critical as that of the
139  * CPUTLBEntry. (This is also why we don't want to combine the two
140  * structs into one.)
141  */
142 typedef struct CPUIOTLBEntry {
143     /*
144      * @addr contains:
145      *  - in the lower TARGET_PAGE_BITS, a physical section number
146      *  - with the lower TARGET_PAGE_BITS masked off, an offset which
147      *    must be added to the virtual address to obtain:
148      *     + the ram_addr_t of the target RAM (if the physical section
149      *       number is PHYS_SECTION_NOTDIRTY or PHYS_SECTION_ROM)
150      *     + the offset within the target MemoryRegion (otherwise)
151      */
152     hwaddr addr;
153     MemTxAttrs attrs;
154 } CPUIOTLBEntry;
155 
156 /*
157  * Data elements that are per MMU mode, minus the bits accessed by
158  * the TCG fast path.
159  */
160 typedef struct CPUTLBDesc {
161     /*
162      * Describe a region covering all of the large pages allocated
163      * into the tlb.  When any page within this region is flushed,
164      * we must flush the entire tlb.  The region is matched if
165      * (addr & large_page_mask) == large_page_addr.
166      */
167     target_ulong large_page_addr;
168     target_ulong large_page_mask;
169     /* host time (in ns) at the beginning of the time window */
170     int64_t window_begin_ns;
171     /* maximum number of entries observed in the window */
172     size_t window_max_entries;
173     size_t n_used_entries;
174     /* The next index to use in the tlb victim table.  */
175     size_t vindex;
176     /* The tlb victim table, in two parts.  */
177     CPUTLBEntry vtable[CPU_VTLB_SIZE];
178     CPUIOTLBEntry viotlb[CPU_VTLB_SIZE];
179     /* The iotlb.  */
180     CPUIOTLBEntry *iotlb;
181 } CPUTLBDesc;
182 
183 /*
184  * Data elements that are per MMU mode, accessed by the fast path.
185  * The structure is aligned to aid loading the pair with one insn.
186  */
187 typedef struct CPUTLBDescFast {
188     /* Contains (n_entries - 1) << CPU_TLB_ENTRY_BITS */
189     uintptr_t mask;
190     /* The array of tlb entries itself. */
191     CPUTLBEntry *table;
192 } CPUTLBDescFast QEMU_ALIGNED(2 * sizeof(void *));
193 
194 /*
195  * Data elements that are shared between all MMU modes.
196  */
197 typedef struct CPUTLBCommon {
198     /* Serialize updates to f.table and d.vtable, and others as noted. */
199     QemuSpin lock;
200     /*
201      * Within dirty, for each bit N, modifications have been made to
202      * mmu_idx N since the last time that mmu_idx was flushed.
203      * Protected by tlb_c.lock.
204      */
205     uint16_t dirty;
206     /*
207      * Statistics.  These are not lock protected, but are read and
208      * written atomically.  This allows the monitor to print a snapshot
209      * of the stats without interfering with the cpu.
210      */
211     size_t full_flush_count;
212     size_t part_flush_count;
213     size_t elide_flush_count;
214 } CPUTLBCommon;
215 
216 /*
217  * The entire softmmu tlb, for all MMU modes.
218  * The meaning of each of the MMU modes is defined in the target code.
219  * Since this is placed within CPUNegativeOffsetState, the smallest
220  * negative offsets are at the end of the struct.
221  */
222 
223 typedef struct CPUTLB {
224     CPUTLBCommon c;
225     CPUTLBDesc d[NB_MMU_MODES];
226     CPUTLBDescFast f[NB_MMU_MODES];
227 } CPUTLB;
228 
229 /* This will be used by TCG backends to compute offsets.  */
230 #define TLB_MASK_TABLE_OFS(IDX) \
231     ((int)offsetof(ArchCPU, neg.tlb.f[IDX]) - (int)offsetof(ArchCPU, env))
232 
233 #else
234 
235 typedef struct CPUTLB { } CPUTLB;
236 
237 #endif  /* !CONFIG_USER_ONLY && CONFIG_TCG */
238 
239 /*
240  * This structure must be placed in ArchCPU immediately
241  * before CPUArchState, as a field named "neg".
242  */
243 typedef struct CPUNegativeOffsetState {
244     CPUTLB tlb;
245     IcountDecr icount_decr;
246 } CPUNegativeOffsetState;
247 
248 #endif
249