xref: /openbmc/qemu/target/riscv/cpu.h (revision 7cbcc538)
1 /*
2  * QEMU RISC-V CPU
3  *
4  * Copyright (c) 2016-2017 Sagar Karandikar, sagark@eecs.berkeley.edu
5  * Copyright (c) 2017-2018 SiFive, Inc.
6  *
7  * This program is free software; you can redistribute it and/or modify it
8  * under the terms and conditions of the GNU General Public License,
9  * version 2 or later, as published by the Free Software Foundation.
10  *
11  * This program is distributed in the hope it will be useful, but WITHOUT
12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
14  * more details.
15  *
16  * You should have received a copy of the GNU General Public License along with
17  * this program.  If not, see <http://www.gnu.org/licenses/>.
18  */
19 
20 #ifndef RISCV_CPU_H
21 #define RISCV_CPU_H
22 
23 #include "hw/core/cpu.h"
24 #include "hw/registerfields.h"
25 #include "exec/cpu-defs.h"
26 #include "qemu/cpu-float.h"
27 #include "qom/object.h"
28 #include "qemu/int128.h"
29 #include "cpu_bits.h"
30 
31 #define TCG_GUEST_DEFAULT_MO 0
32 
33 /*
34  * RISC-V-specific extra insn start words:
35  * 1: Original instruction opcode
36  */
37 #define TARGET_INSN_START_EXTRA_WORDS 1
38 
39 #define TYPE_RISCV_CPU "riscv-cpu"
40 
41 #define RISCV_CPU_TYPE_SUFFIX "-" TYPE_RISCV_CPU
42 #define RISCV_CPU_TYPE_NAME(name) (name RISCV_CPU_TYPE_SUFFIX)
43 #define CPU_RESOLVING_TYPE TYPE_RISCV_CPU
44 
45 #define TYPE_RISCV_CPU_ANY              RISCV_CPU_TYPE_NAME("any")
46 #define TYPE_RISCV_CPU_BASE32           RISCV_CPU_TYPE_NAME("rv32")
47 #define TYPE_RISCV_CPU_BASE64           RISCV_CPU_TYPE_NAME("rv64")
48 #define TYPE_RISCV_CPU_BASE128          RISCV_CPU_TYPE_NAME("x-rv128")
49 #define TYPE_RISCV_CPU_IBEX             RISCV_CPU_TYPE_NAME("lowrisc-ibex")
50 #define TYPE_RISCV_CPU_SHAKTI_C         RISCV_CPU_TYPE_NAME("shakti-c")
51 #define TYPE_RISCV_CPU_SIFIVE_E31       RISCV_CPU_TYPE_NAME("sifive-e31")
52 #define TYPE_RISCV_CPU_SIFIVE_E34       RISCV_CPU_TYPE_NAME("sifive-e34")
53 #define TYPE_RISCV_CPU_SIFIVE_E51       RISCV_CPU_TYPE_NAME("sifive-e51")
54 #define TYPE_RISCV_CPU_SIFIVE_U34       RISCV_CPU_TYPE_NAME("sifive-u34")
55 #define TYPE_RISCV_CPU_SIFIVE_U54       RISCV_CPU_TYPE_NAME("sifive-u54")
56 #define TYPE_RISCV_CPU_HOST             RISCV_CPU_TYPE_NAME("host")
57 
58 #if defined(TARGET_RISCV32)
59 # define TYPE_RISCV_CPU_BASE            TYPE_RISCV_CPU_BASE32
60 #elif defined(TARGET_RISCV64)
61 # define TYPE_RISCV_CPU_BASE            TYPE_RISCV_CPU_BASE64
62 #endif
63 
64 #define RV(x) ((target_ulong)1 << (x - 'A'))
65 
66 #define RVI RV('I')
67 #define RVE RV('E') /* E and I are mutually exclusive */
68 #define RVM RV('M')
69 #define RVA RV('A')
70 #define RVF RV('F')
71 #define RVD RV('D')
72 #define RVV RV('V')
73 #define RVC RV('C')
74 #define RVS RV('S')
75 #define RVU RV('U')
76 #define RVH RV('H')
77 #define RVJ RV('J')
78 
79 /* S extension denotes that Supervisor mode exists, however it is possible
80    to have a core that support S mode but does not have an MMU and there
81    is currently no bit in misa to indicate whether an MMU exists or not
82    so a cpu features bitfield is required, likewise for optional PMP support */
83 enum {
84     RISCV_FEATURE_MMU,
85     RISCV_FEATURE_PMP,
86     RISCV_FEATURE_EPMP,
87     RISCV_FEATURE_MISA,
88     RISCV_FEATURE_DEBUG
89 };
90 
91 /* Privileged specification version */
92 enum {
93     PRIV_VERSION_1_10_0 = 0,
94     PRIV_VERSION_1_11_0,
95     PRIV_VERSION_1_12_0,
96 };
97 
98 #define VEXT_VERSION_1_00_0 0x00010000
99 
100 enum {
101     TRANSLATE_SUCCESS,
102     TRANSLATE_FAIL,
103     TRANSLATE_PMP_FAIL,
104     TRANSLATE_G_STAGE_FAIL
105 };
106 
107 #define MMU_USER_IDX 3
108 
109 #define MAX_RISCV_PMPS (16)
110 
111 typedef struct CPUArchState CPURISCVState;
112 
113 #if !defined(CONFIG_USER_ONLY)
114 #include "pmp.h"
115 #include "debug.h"
116 #endif
117 
118 #define RV_VLEN_MAX 1024
119 #define RV_MAX_MHPMEVENTS 32
120 #define RV_MAX_MHPMCOUNTERS 32
121 
122 FIELD(VTYPE, VLMUL, 0, 3)
123 FIELD(VTYPE, VSEW, 3, 3)
124 FIELD(VTYPE, VTA, 6, 1)
125 FIELD(VTYPE, VMA, 7, 1)
126 FIELD(VTYPE, VEDIV, 8, 2)
127 FIELD(VTYPE, RESERVED, 10, sizeof(target_ulong) * 8 - 11)
128 
129 typedef struct PMUCTRState {
130     /* Current value of a counter */
131     target_ulong mhpmcounter_val;
132     /* Current value of a counter in RV32*/
133     target_ulong mhpmcounterh_val;
134     /* Snapshot values of counter */
135     target_ulong mhpmcounter_prev;
136     /* Snapshort value of a counter in RV32 */
137     target_ulong mhpmcounterh_prev;
138     bool started;
139 } PMUCTRState;
140 
141 struct CPUArchState {
142     target_ulong gpr[32];
143     target_ulong gprh[32]; /* 64 top bits of the 128-bit registers */
144     uint64_t fpr[32]; /* assume both F and D extensions */
145 
146     /* vector coprocessor state. */
147     uint64_t vreg[32 * RV_VLEN_MAX / 64] QEMU_ALIGNED(16);
148     target_ulong vxrm;
149     target_ulong vxsat;
150     target_ulong vl;
151     target_ulong vstart;
152     target_ulong vtype;
153     bool vill;
154 
155     target_ulong pc;
156     target_ulong load_res;
157     target_ulong load_val;
158 
159     target_ulong frm;
160 
161     target_ulong badaddr;
162     target_ulong bins;
163 
164     target_ulong guest_phys_fault_addr;
165 
166     target_ulong priv_ver;
167     target_ulong bext_ver;
168     target_ulong vext_ver;
169 
170     /* RISCVMXL, but uint32_t for vmstate migration */
171     uint32_t misa_mxl;      /* current mxl */
172     uint32_t misa_mxl_max;  /* max mxl for this cpu */
173     uint32_t misa_ext;      /* current extensions */
174     uint32_t misa_ext_mask; /* max ext for this cpu */
175     uint32_t xl;            /* current xlen */
176 
177     /* 128-bit helpers upper part return value */
178     target_ulong retxh;
179 
180     uint32_t features;
181 
182 #ifdef CONFIG_USER_ONLY
183     uint32_t elf_flags;
184 #endif
185 
186 #ifndef CONFIG_USER_ONLY
187     target_ulong priv;
188     /* This contains QEMU specific information about the virt state. */
189     target_ulong virt;
190     target_ulong geilen;
191     target_ulong resetvec;
192 
193     target_ulong mhartid;
194     /*
195      * For RV32 this is 32-bit mstatus and 32-bit mstatush.
196      * For RV64 this is a 64-bit mstatus.
197      */
198     uint64_t mstatus;
199 
200     uint64_t mip;
201     /*
202      * MIP contains the software writable version of SEIP ORed with the
203      * external interrupt value. The MIP register is always up-to-date.
204      * To keep track of the current source, we also save booleans of the values
205      * here.
206      */
207     bool external_seip;
208     bool software_seip;
209 
210     uint64_t miclaim;
211 
212     uint64_t mie;
213     uint64_t mideleg;
214 
215     target_ulong satp;   /* since: priv-1.10.0 */
216     target_ulong stval;
217     target_ulong medeleg;
218 
219     target_ulong stvec;
220     target_ulong sepc;
221     target_ulong scause;
222 
223     target_ulong mtvec;
224     target_ulong mepc;
225     target_ulong mcause;
226     target_ulong mtval;  /* since: priv-1.10.0 */
227 
228     /* Machine and Supervisor interrupt priorities */
229     uint8_t miprio[64];
230     uint8_t siprio[64];
231 
232     /* AIA CSRs */
233     target_ulong miselect;
234     target_ulong siselect;
235 
236     /* Hypervisor CSRs */
237     target_ulong hstatus;
238     target_ulong hedeleg;
239     uint64_t hideleg;
240     target_ulong hcounteren;
241     target_ulong htval;
242     target_ulong htinst;
243     target_ulong hgatp;
244     target_ulong hgeie;
245     target_ulong hgeip;
246     uint64_t htimedelta;
247 
248     /* Hypervisor controlled virtual interrupt priorities */
249     target_ulong hvictl;
250     uint8_t hviprio[64];
251 
252     /* Upper 64-bits of 128-bit CSRs */
253     uint64_t mscratchh;
254     uint64_t sscratchh;
255 
256     /* Virtual CSRs */
257     /*
258      * For RV32 this is 32-bit vsstatus and 32-bit vsstatush.
259      * For RV64 this is a 64-bit vsstatus.
260      */
261     uint64_t vsstatus;
262     target_ulong vstvec;
263     target_ulong vsscratch;
264     target_ulong vsepc;
265     target_ulong vscause;
266     target_ulong vstval;
267     target_ulong vsatp;
268 
269     /* AIA VS-mode CSRs */
270     target_ulong vsiselect;
271 
272     target_ulong mtval2;
273     target_ulong mtinst;
274 
275     /* HS Backup CSRs */
276     target_ulong stvec_hs;
277     target_ulong sscratch_hs;
278     target_ulong sepc_hs;
279     target_ulong scause_hs;
280     target_ulong stval_hs;
281     target_ulong satp_hs;
282     uint64_t mstatus_hs;
283 
284     /* Signals whether the current exception occurred with two-stage address
285        translation active. */
286     bool two_stage_lookup;
287     /*
288      * Signals whether the current exception occurred while doing two-stage
289      * address translation for the VS-stage page table walk.
290      */
291     bool two_stage_indirect_lookup;
292 
293     target_ulong scounteren;
294     target_ulong mcounteren;
295 
296     target_ulong mcountinhibit;
297 
298     /* PMU counter state */
299     PMUCTRState pmu_ctrs[RV_MAX_MHPMCOUNTERS];
300 
301     /* PMU event selector configured values. First three are unused*/
302     target_ulong mhpmevent_val[RV_MAX_MHPMEVENTS];
303 
304     target_ulong sscratch;
305     target_ulong mscratch;
306 
307     /* temporary htif regs */
308     uint64_t mfromhost;
309     uint64_t mtohost;
310 
311     /* physical memory protection */
312     pmp_table_t pmp_state;
313     target_ulong mseccfg;
314 
315     /* trigger module */
316     target_ulong trigger_cur;
317     type2_trigger_t type2_trig[TRIGGER_TYPE2_NUM];
318 
319     /* machine specific rdtime callback */
320     uint64_t (*rdtime_fn)(void *);
321     void *rdtime_fn_arg;
322 
323     /* machine specific AIA ireg read-modify-write callback */
324 #define AIA_MAKE_IREG(__isel, __priv, __virt, __vgein, __xlen) \
325     ((((__xlen) & 0xff) << 24) | \
326      (((__vgein) & 0x3f) << 20) | \
327      (((__virt) & 0x1) << 18) | \
328      (((__priv) & 0x3) << 16) | \
329      (__isel & 0xffff))
330 #define AIA_IREG_ISEL(__ireg)                  ((__ireg) & 0xffff)
331 #define AIA_IREG_PRIV(__ireg)                  (((__ireg) >> 16) & 0x3)
332 #define AIA_IREG_VIRT(__ireg)                  (((__ireg) >> 18) & 0x1)
333 #define AIA_IREG_VGEIN(__ireg)                 (((__ireg) >> 20) & 0x3f)
334 #define AIA_IREG_XLEN(__ireg)                  (((__ireg) >> 24) & 0xff)
335     int (*aia_ireg_rmw_fn[4])(void *arg, target_ulong reg,
336         target_ulong *val, target_ulong new_val, target_ulong write_mask);
337     void *aia_ireg_rmw_fn_arg[4];
338 
339     /* True if in debugger mode.  */
340     bool debugger;
341 
342     /*
343      * CSRs for PointerMasking extension
344      */
345     target_ulong mmte;
346     target_ulong mpmmask;
347     target_ulong mpmbase;
348     target_ulong spmmask;
349     target_ulong spmbase;
350     target_ulong upmmask;
351     target_ulong upmbase;
352 
353     /* CSRs for execution enviornment configuration */
354     uint64_t menvcfg;
355     target_ulong senvcfg;
356     uint64_t henvcfg;
357 #endif
358     target_ulong cur_pmmask;
359     target_ulong cur_pmbase;
360 
361     float_status fp_status;
362 
363     /* Fields from here on are preserved across CPU reset. */
364 
365     hwaddr kernel_addr;
366     hwaddr fdt_addr;
367 
368     /* kvm timer */
369     bool kvm_timer_dirty;
370     uint64_t kvm_timer_time;
371     uint64_t kvm_timer_compare;
372     uint64_t kvm_timer_state;
373     uint64_t kvm_timer_frequency;
374 };
375 
376 OBJECT_DECLARE_CPU_TYPE(RISCVCPU, RISCVCPUClass, RISCV_CPU)
377 
378 /**
379  * RISCVCPUClass:
380  * @parent_realize: The parent class' realize handler.
381  * @parent_reset: The parent class' reset handler.
382  *
383  * A RISCV CPU model.
384  */
385 struct RISCVCPUClass {
386     /*< private >*/
387     CPUClass parent_class;
388     /*< public >*/
389     DeviceRealize parent_realize;
390     DeviceReset parent_reset;
391 };
392 
393 struct RISCVCPUConfig {
394     bool ext_i;
395     bool ext_e;
396     bool ext_g;
397     bool ext_m;
398     bool ext_a;
399     bool ext_f;
400     bool ext_d;
401     bool ext_c;
402     bool ext_s;
403     bool ext_u;
404     bool ext_h;
405     bool ext_j;
406     bool ext_v;
407     bool ext_zba;
408     bool ext_zbb;
409     bool ext_zbc;
410     bool ext_zbkb;
411     bool ext_zbkc;
412     bool ext_zbkx;
413     bool ext_zbs;
414     bool ext_zk;
415     bool ext_zkn;
416     bool ext_zknd;
417     bool ext_zkne;
418     bool ext_zknh;
419     bool ext_zkr;
420     bool ext_zks;
421     bool ext_zksed;
422     bool ext_zksh;
423     bool ext_zkt;
424     bool ext_ifencei;
425     bool ext_icsr;
426     bool ext_zihintpause;
427     bool ext_svinval;
428     bool ext_svnapot;
429     bool ext_svpbmt;
430     bool ext_zdinx;
431     bool ext_zfh;
432     bool ext_zfhmin;
433     bool ext_zfinx;
434     bool ext_zhinx;
435     bool ext_zhinxmin;
436     bool ext_zve32f;
437     bool ext_zve64f;
438     bool ext_zmmul;
439     bool ext_smaia;
440     bool ext_ssaia;
441     bool rvv_ta_all_1s;
442     bool rvv_ma_all_1s;
443 
444     uint32_t mvendorid;
445     uint64_t marchid;
446     uint64_t mimpid;
447 
448     /* Vendor-specific custom extensions */
449     bool ext_XVentanaCondOps;
450 
451     uint8_t pmu_num;
452     char *priv_spec;
453     char *user_spec;
454     char *bext_spec;
455     char *vext_spec;
456     uint16_t vlen;
457     uint16_t elen;
458     bool mmu;
459     bool pmp;
460     bool epmp;
461     bool debug;
462     uint64_t resetvec;
463 
464     bool short_isa_string;
465 };
466 
467 typedef struct RISCVCPUConfig RISCVCPUConfig;
468 
469 /**
470  * RISCVCPU:
471  * @env: #CPURISCVState
472  *
473  * A RISCV CPU.
474  */
475 struct ArchCPU {
476     /*< private >*/
477     CPUState parent_obj;
478     /*< public >*/
479     CPUNegativeOffsetState neg;
480     CPURISCVState env;
481 
482     char *dyn_csr_xml;
483     char *dyn_vreg_xml;
484 
485     /* Configuration Settings */
486     RISCVCPUConfig cfg;
487 };
488 
489 static inline int riscv_has_ext(CPURISCVState *env, target_ulong ext)
490 {
491     return (env->misa_ext & ext) != 0;
492 }
493 
494 static inline bool riscv_feature(CPURISCVState *env, int feature)
495 {
496     return env->features & (1ULL << feature);
497 }
498 
499 static inline void riscv_set_feature(CPURISCVState *env, int feature)
500 {
501     env->features |= (1ULL << feature);
502 }
503 
504 #include "cpu_user.h"
505 
506 extern const char * const riscv_int_regnames[];
507 extern const char * const riscv_int_regnamesh[];
508 extern const char * const riscv_fpr_regnames[];
509 
510 const char *riscv_cpu_get_trap_name(target_ulong cause, bool async);
511 void riscv_cpu_do_interrupt(CPUState *cpu);
512 int riscv_cpu_write_elf64_note(WriteCoreDumpFunction f, CPUState *cs,
513                                int cpuid, void *opaque);
514 int riscv_cpu_write_elf32_note(WriteCoreDumpFunction f, CPUState *cs,
515                                int cpuid, void *opaque);
516 int riscv_cpu_gdb_read_register(CPUState *cpu, GByteArray *buf, int reg);
517 int riscv_cpu_gdb_write_register(CPUState *cpu, uint8_t *buf, int reg);
518 int riscv_cpu_hviprio_index2irq(int index, int *out_irq, int *out_rdzero);
519 uint8_t riscv_cpu_default_priority(int irq);
520 uint64_t riscv_cpu_all_pending(CPURISCVState *env);
521 int riscv_cpu_mirq_pending(CPURISCVState *env);
522 int riscv_cpu_sirq_pending(CPURISCVState *env);
523 int riscv_cpu_vsirq_pending(CPURISCVState *env);
524 bool riscv_cpu_fp_enabled(CPURISCVState *env);
525 target_ulong riscv_cpu_get_geilen(CPURISCVState *env);
526 void riscv_cpu_set_geilen(CPURISCVState *env, target_ulong geilen);
527 bool riscv_cpu_vector_enabled(CPURISCVState *env);
528 bool riscv_cpu_virt_enabled(CPURISCVState *env);
529 void riscv_cpu_set_virt_enabled(CPURISCVState *env, bool enable);
530 bool riscv_cpu_two_stage_lookup(int mmu_idx);
531 int riscv_cpu_mmu_index(CPURISCVState *env, bool ifetch);
532 hwaddr riscv_cpu_get_phys_page_debug(CPUState *cpu, vaddr addr);
533 G_NORETURN void  riscv_cpu_do_unaligned_access(CPUState *cs, vaddr addr,
534                                                MMUAccessType access_type, int mmu_idx,
535                                                uintptr_t retaddr);
536 bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
537                         MMUAccessType access_type, int mmu_idx,
538                         bool probe, uintptr_t retaddr);
539 void riscv_cpu_do_transaction_failed(CPUState *cs, hwaddr physaddr,
540                                      vaddr addr, unsigned size,
541                                      MMUAccessType access_type,
542                                      int mmu_idx, MemTxAttrs attrs,
543                                      MemTxResult response, uintptr_t retaddr);
544 char *riscv_isa_string(RISCVCPU *cpu);
545 void riscv_cpu_list(void);
546 
547 #define cpu_list riscv_cpu_list
548 #define cpu_mmu_index riscv_cpu_mmu_index
549 
550 #ifndef CONFIG_USER_ONLY
551 bool riscv_cpu_exec_interrupt(CPUState *cs, int interrupt_request);
552 void riscv_cpu_swap_hypervisor_regs(CPURISCVState *env);
553 int riscv_cpu_claim_interrupts(RISCVCPU *cpu, uint64_t interrupts);
554 uint64_t riscv_cpu_update_mip(RISCVCPU *cpu, uint64_t mask, uint64_t value);
555 #define BOOL_TO_MASK(x) (-!!(x)) /* helper for riscv_cpu_update_mip value */
556 void riscv_cpu_set_rdtime_fn(CPURISCVState *env, uint64_t (*fn)(void *),
557                              void *arg);
558 void riscv_cpu_set_aia_ireg_rmw_fn(CPURISCVState *env, uint32_t priv,
559                                    int (*rmw_fn)(void *arg,
560                                                  target_ulong reg,
561                                                  target_ulong *val,
562                                                  target_ulong new_val,
563                                                  target_ulong write_mask),
564                                    void *rmw_fn_arg);
565 #endif
566 void riscv_cpu_set_mode(CPURISCVState *env, target_ulong newpriv);
567 
568 void riscv_translate_init(void);
569 G_NORETURN void riscv_raise_exception(CPURISCVState *env,
570                                       uint32_t exception, uintptr_t pc);
571 
572 target_ulong riscv_cpu_get_fflags(CPURISCVState *env);
573 void riscv_cpu_set_fflags(CPURISCVState *env, target_ulong);
574 
575 #define TB_FLAGS_PRIV_MMU_MASK                3
576 #define TB_FLAGS_PRIV_HYP_ACCESS_MASK   (1 << 2)
577 #define TB_FLAGS_MSTATUS_FS MSTATUS_FS
578 #define TB_FLAGS_MSTATUS_VS MSTATUS_VS
579 
580 #include "exec/cpu-all.h"
581 
582 FIELD(TB_FLAGS, MEM_IDX, 0, 3)
583 FIELD(TB_FLAGS, LMUL, 3, 3)
584 FIELD(TB_FLAGS, SEW, 6, 3)
585 /* Skip MSTATUS_VS (0x600) bits */
586 FIELD(TB_FLAGS, VL_EQ_VLMAX, 11, 1)
587 FIELD(TB_FLAGS, VILL, 12, 1)
588 /* Skip MSTATUS_FS (0x6000) bits */
589 /* Is a Hypervisor instruction load/store allowed? */
590 FIELD(TB_FLAGS, HLSX, 15, 1)
591 FIELD(TB_FLAGS, MSTATUS_HS_FS, 16, 2)
592 FIELD(TB_FLAGS, MSTATUS_HS_VS, 18, 2)
593 /* The combination of MXL/SXL/UXL that applies to the current cpu mode. */
594 FIELD(TB_FLAGS, XL, 20, 2)
595 /* If PointerMasking should be applied */
596 FIELD(TB_FLAGS, PM_MASK_ENABLED, 22, 1)
597 FIELD(TB_FLAGS, PM_BASE_ENABLED, 23, 1)
598 FIELD(TB_FLAGS, VTA, 24, 1)
599 FIELD(TB_FLAGS, VMA, 25, 1)
600 
601 #ifdef TARGET_RISCV32
602 #define riscv_cpu_mxl(env)  ((void)(env), MXL_RV32)
603 #else
604 static inline RISCVMXL riscv_cpu_mxl(CPURISCVState *env)
605 {
606     return env->misa_mxl;
607 }
608 #endif
609 #define riscv_cpu_mxl_bits(env) (1UL << (4 + riscv_cpu_mxl(env)))
610 
611 #if defined(TARGET_RISCV32)
612 #define cpu_recompute_xl(env)  ((void)(env), MXL_RV32)
613 #else
614 static inline RISCVMXL cpu_recompute_xl(CPURISCVState *env)
615 {
616     RISCVMXL xl = env->misa_mxl;
617 #if !defined(CONFIG_USER_ONLY)
618     /*
619      * When emulating a 32-bit-only cpu, use RV32.
620      * When emulating a 64-bit cpu, and MXL has been reduced to RV32,
621      * MSTATUSH doesn't have UXL/SXL, therefore XLEN cannot be widened
622      * back to RV64 for lower privs.
623      */
624     if (xl != MXL_RV32) {
625         switch (env->priv) {
626         case PRV_M:
627             break;
628         case PRV_U:
629             xl = get_field(env->mstatus, MSTATUS64_UXL);
630             break;
631         default: /* PRV_S | PRV_H */
632             xl = get_field(env->mstatus, MSTATUS64_SXL);
633             break;
634         }
635     }
636 #endif
637     return xl;
638 }
639 #endif
640 
641 static inline int riscv_cpu_xlen(CPURISCVState *env)
642 {
643     return 16 << env->xl;
644 }
645 
646 #ifdef TARGET_RISCV32
647 #define riscv_cpu_sxl(env)  ((void)(env), MXL_RV32)
648 #else
649 static inline RISCVMXL riscv_cpu_sxl(CPURISCVState *env)
650 {
651 #ifdef CONFIG_USER_ONLY
652     return env->misa_mxl;
653 #else
654     return get_field(env->mstatus, MSTATUS64_SXL);
655 #endif
656 }
657 #endif
658 
659 /*
660  * Encode LMUL to lmul as follows:
661  *     LMUL    vlmul    lmul
662  *      1       000       0
663  *      2       001       1
664  *      4       010       2
665  *      8       011       3
666  *      -       100       -
667  *     1/8      101      -3
668  *     1/4      110      -2
669  *     1/2      111      -1
670  *
671  * then, we can calculate VLMAX = vlen >> (vsew + 3 - lmul)
672  * e.g. vlen = 256 bits, SEW = 16, LMUL = 1/8
673  *      => VLMAX = vlen >> (1 + 3 - (-3))
674  *               = 256 >> 7
675  *               = 2
676  */
677 static inline uint32_t vext_get_vlmax(RISCVCPU *cpu, target_ulong vtype)
678 {
679     uint8_t sew = FIELD_EX64(vtype, VTYPE, VSEW);
680     int8_t lmul = sextract32(FIELD_EX64(vtype, VTYPE, VLMUL), 0, 3);
681     return cpu->cfg.vlen >> (sew + 3 - lmul);
682 }
683 
684 void cpu_get_tb_cpu_state(CPURISCVState *env, target_ulong *pc,
685                           target_ulong *cs_base, uint32_t *pflags);
686 
687 void riscv_cpu_update_mask(CPURISCVState *env);
688 
689 RISCVException riscv_csrrw(CPURISCVState *env, int csrno,
690                            target_ulong *ret_value,
691                            target_ulong new_value, target_ulong write_mask);
692 RISCVException riscv_csrrw_debug(CPURISCVState *env, int csrno,
693                                  target_ulong *ret_value,
694                                  target_ulong new_value,
695                                  target_ulong write_mask);
696 
697 static inline void riscv_csr_write(CPURISCVState *env, int csrno,
698                                    target_ulong val)
699 {
700     riscv_csrrw(env, csrno, NULL, val, MAKE_64BIT_MASK(0, TARGET_LONG_BITS));
701 }
702 
703 static inline target_ulong riscv_csr_read(CPURISCVState *env, int csrno)
704 {
705     target_ulong val = 0;
706     riscv_csrrw(env, csrno, &val, 0, 0);
707     return val;
708 }
709 
710 typedef RISCVException (*riscv_csr_predicate_fn)(CPURISCVState *env,
711                                                  int csrno);
712 typedef RISCVException (*riscv_csr_read_fn)(CPURISCVState *env, int csrno,
713                                             target_ulong *ret_value);
714 typedef RISCVException (*riscv_csr_write_fn)(CPURISCVState *env, int csrno,
715                                              target_ulong new_value);
716 typedef RISCVException (*riscv_csr_op_fn)(CPURISCVState *env, int csrno,
717                                           target_ulong *ret_value,
718                                           target_ulong new_value,
719                                           target_ulong write_mask);
720 
721 RISCVException riscv_csrrw_i128(CPURISCVState *env, int csrno,
722                                 Int128 *ret_value,
723                                 Int128 new_value, Int128 write_mask);
724 
725 typedef RISCVException (*riscv_csr_read128_fn)(CPURISCVState *env, int csrno,
726                                                Int128 *ret_value);
727 typedef RISCVException (*riscv_csr_write128_fn)(CPURISCVState *env, int csrno,
728                                              Int128 new_value);
729 
730 typedef struct {
731     const char *name;
732     riscv_csr_predicate_fn predicate;
733     riscv_csr_read_fn read;
734     riscv_csr_write_fn write;
735     riscv_csr_op_fn op;
736     riscv_csr_read128_fn read128;
737     riscv_csr_write128_fn write128;
738     /* The default priv spec version should be PRIV_VERSION_1_10_0 (i.e 0) */
739     uint32_t min_priv_ver;
740 } riscv_csr_operations;
741 
742 /* CSR function table constants */
743 enum {
744     CSR_TABLE_SIZE = 0x1000
745 };
746 
747 /* CSR function table */
748 extern riscv_csr_operations csr_ops[CSR_TABLE_SIZE];
749 
750 void riscv_get_csr_ops(int csrno, riscv_csr_operations *ops);
751 void riscv_set_csr_ops(int csrno, riscv_csr_operations *ops);
752 
753 void riscv_cpu_register_gdb_regs_for_features(CPUState *cs);
754 
755 #endif /* RISCV_CPU_H */
756