xref: /openbmc/qemu/target/riscv/cpu.h (revision 355d5584)
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_AIA,
89     RISCV_FEATURE_DEBUG
90 };
91 
92 /* Privileged specification version */
93 enum {
94     PRIV_VERSION_1_10_0 = 0,
95     PRIV_VERSION_1_11_0,
96     PRIV_VERSION_1_12_0,
97 };
98 
99 #define VEXT_VERSION_1_00_0 0x00010000
100 
101 enum {
102     TRANSLATE_SUCCESS,
103     TRANSLATE_FAIL,
104     TRANSLATE_PMP_FAIL,
105     TRANSLATE_G_STAGE_FAIL
106 };
107 
108 #define MMU_USER_IDX 3
109 
110 #define MAX_RISCV_PMPS (16)
111 
112 typedef struct CPUArchState CPURISCVState;
113 
114 #if !defined(CONFIG_USER_ONLY)
115 #include "pmp.h"
116 #include "debug.h"
117 #endif
118 
119 #define RV_VLEN_MAX 1024
120 #define RV_MAX_MHPMEVENTS 32
121 #define RV_MAX_MHPMCOUNTERS 32
122 
123 FIELD(VTYPE, VLMUL, 0, 3)
124 FIELD(VTYPE, VSEW, 3, 3)
125 FIELD(VTYPE, VTA, 6, 1)
126 FIELD(VTYPE, VMA, 7, 1)
127 FIELD(VTYPE, VEDIV, 8, 2)
128 FIELD(VTYPE, RESERVED, 10, sizeof(target_ulong) * 8 - 11)
129 
130 typedef struct PMUCTRState {
131     /* Current value of a counter */
132     target_ulong mhpmcounter_val;
133     /* Current value of a counter in RV32*/
134     target_ulong mhpmcounterh_val;
135     /* Snapshot values of counter */
136     target_ulong mhpmcounter_prev;
137     /* Snapshort value of a counter in RV32 */
138     target_ulong mhpmcounterh_prev;
139     bool started;
140 } PMUCTRState;
141 
142 struct CPUArchState {
143     target_ulong gpr[32];
144     target_ulong gprh[32]; /* 64 top bits of the 128-bit registers */
145     uint64_t fpr[32]; /* assume both F and D extensions */
146 
147     /* vector coprocessor state. */
148     uint64_t vreg[32 * RV_VLEN_MAX / 64] QEMU_ALIGNED(16);
149     target_ulong vxrm;
150     target_ulong vxsat;
151     target_ulong vl;
152     target_ulong vstart;
153     target_ulong vtype;
154     bool vill;
155 
156     target_ulong pc;
157     target_ulong load_res;
158     target_ulong load_val;
159 
160     target_ulong frm;
161 
162     target_ulong badaddr;
163     target_ulong bins;
164 
165     target_ulong guest_phys_fault_addr;
166 
167     target_ulong priv_ver;
168     target_ulong bext_ver;
169     target_ulong vext_ver;
170 
171     /* RISCVMXL, but uint32_t for vmstate migration */
172     uint32_t misa_mxl;      /* current mxl */
173     uint32_t misa_mxl_max;  /* max mxl for this cpu */
174     uint32_t misa_ext;      /* current extensions */
175     uint32_t misa_ext_mask; /* max ext for this cpu */
176     uint32_t xl;            /* current xlen */
177 
178     /* 128-bit helpers upper part return value */
179     target_ulong retxh;
180 
181     uint32_t features;
182 
183 #ifdef CONFIG_USER_ONLY
184     uint32_t elf_flags;
185 #endif
186 
187 #ifndef CONFIG_USER_ONLY
188     target_ulong priv;
189     /* This contains QEMU specific information about the virt state. */
190     target_ulong virt;
191     target_ulong geilen;
192     target_ulong resetvec;
193 
194     target_ulong mhartid;
195     /*
196      * For RV32 this is 32-bit mstatus and 32-bit mstatush.
197      * For RV64 this is a 64-bit mstatus.
198      */
199     uint64_t mstatus;
200 
201     uint64_t mip;
202     /*
203      * MIP contains the software writable version of SEIP ORed with the
204      * external interrupt value. The MIP register is always up-to-date.
205      * To keep track of the current source, we also save booleans of the values
206      * here.
207      */
208     bool external_seip;
209     bool software_seip;
210 
211     uint64_t miclaim;
212 
213     uint64_t mie;
214     uint64_t mideleg;
215 
216     target_ulong satp;   /* since: priv-1.10.0 */
217     target_ulong stval;
218     target_ulong medeleg;
219 
220     target_ulong stvec;
221     target_ulong sepc;
222     target_ulong scause;
223 
224     target_ulong mtvec;
225     target_ulong mepc;
226     target_ulong mcause;
227     target_ulong mtval;  /* since: priv-1.10.0 */
228 
229     /* Machine and Supervisor interrupt priorities */
230     uint8_t miprio[64];
231     uint8_t siprio[64];
232 
233     /* AIA CSRs */
234     target_ulong miselect;
235     target_ulong siselect;
236 
237     /* Hypervisor CSRs */
238     target_ulong hstatus;
239     target_ulong hedeleg;
240     uint64_t hideleg;
241     target_ulong hcounteren;
242     target_ulong htval;
243     target_ulong htinst;
244     target_ulong hgatp;
245     target_ulong hgeie;
246     target_ulong hgeip;
247     uint64_t htimedelta;
248 
249     /* Hypervisor controlled virtual interrupt priorities */
250     target_ulong hvictl;
251     uint8_t hviprio[64];
252 
253     /* Upper 64-bits of 128-bit CSRs */
254     uint64_t mscratchh;
255     uint64_t sscratchh;
256 
257     /* Virtual CSRs */
258     /*
259      * For RV32 this is 32-bit vsstatus and 32-bit vsstatush.
260      * For RV64 this is a 64-bit vsstatus.
261      */
262     uint64_t vsstatus;
263     target_ulong vstvec;
264     target_ulong vsscratch;
265     target_ulong vsepc;
266     target_ulong vscause;
267     target_ulong vstval;
268     target_ulong vsatp;
269 
270     /* AIA VS-mode CSRs */
271     target_ulong vsiselect;
272 
273     target_ulong mtval2;
274     target_ulong mtinst;
275 
276     /* HS Backup CSRs */
277     target_ulong stvec_hs;
278     target_ulong sscratch_hs;
279     target_ulong sepc_hs;
280     target_ulong scause_hs;
281     target_ulong stval_hs;
282     target_ulong satp_hs;
283     uint64_t mstatus_hs;
284 
285     /* Signals whether the current exception occurred with two-stage address
286        translation active. */
287     bool two_stage_lookup;
288     /*
289      * Signals whether the current exception occurred while doing two-stage
290      * address translation for the VS-stage page table walk.
291      */
292     bool two_stage_indirect_lookup;
293 
294     target_ulong scounteren;
295     target_ulong mcounteren;
296 
297     target_ulong mcountinhibit;
298 
299     /* PMU counter state */
300     PMUCTRState pmu_ctrs[RV_MAX_MHPMCOUNTERS];
301 
302     /* PMU event selector configured values. First three are unused*/
303     target_ulong mhpmevent_val[RV_MAX_MHPMEVENTS];
304 
305     target_ulong sscratch;
306     target_ulong mscratch;
307 
308     /* temporary htif regs */
309     uint64_t mfromhost;
310     uint64_t mtohost;
311     uint64_t timecmp;
312 
313     /* physical memory protection */
314     pmp_table_t pmp_state;
315     target_ulong mseccfg;
316 
317     /* trigger module */
318     target_ulong trigger_cur;
319     type2_trigger_t type2_trig[TRIGGER_TYPE2_NUM];
320 
321     /* machine specific rdtime callback */
322     uint64_t (*rdtime_fn)(void *);
323     void *rdtime_fn_arg;
324 
325     /* machine specific AIA ireg read-modify-write callback */
326 #define AIA_MAKE_IREG(__isel, __priv, __virt, __vgein, __xlen) \
327     ((((__xlen) & 0xff) << 24) | \
328      (((__vgein) & 0x3f) << 20) | \
329      (((__virt) & 0x1) << 18) | \
330      (((__priv) & 0x3) << 16) | \
331      (__isel & 0xffff))
332 #define AIA_IREG_ISEL(__ireg)                  ((__ireg) & 0xffff)
333 #define AIA_IREG_PRIV(__ireg)                  (((__ireg) >> 16) & 0x3)
334 #define AIA_IREG_VIRT(__ireg)                  (((__ireg) >> 18) & 0x1)
335 #define AIA_IREG_VGEIN(__ireg)                 (((__ireg) >> 20) & 0x3f)
336 #define AIA_IREG_XLEN(__ireg)                  (((__ireg) >> 24) & 0xff)
337     int (*aia_ireg_rmw_fn[4])(void *arg, target_ulong reg,
338         target_ulong *val, target_ulong new_val, target_ulong write_mask);
339     void *aia_ireg_rmw_fn_arg[4];
340 
341     /* True if in debugger mode.  */
342     bool debugger;
343 
344     /*
345      * CSRs for PointerMasking extension
346      */
347     target_ulong mmte;
348     target_ulong mpmmask;
349     target_ulong mpmbase;
350     target_ulong spmmask;
351     target_ulong spmbase;
352     target_ulong upmmask;
353     target_ulong upmbase;
354 
355     /* CSRs for execution enviornment configuration */
356     uint64_t menvcfg;
357     target_ulong senvcfg;
358     uint64_t henvcfg;
359 #endif
360     target_ulong cur_pmmask;
361     target_ulong cur_pmbase;
362 
363     float_status fp_status;
364 
365     /* Fields from here on are preserved across CPU reset. */
366     QEMUTimer *timer; /* Internal timer */
367 
368     hwaddr kernel_addr;
369     hwaddr fdt_addr;
370 
371     /* kvm timer */
372     bool kvm_timer_dirty;
373     uint64_t kvm_timer_time;
374     uint64_t kvm_timer_compare;
375     uint64_t kvm_timer_state;
376     uint64_t kvm_timer_frequency;
377 };
378 
379 OBJECT_DECLARE_CPU_TYPE(RISCVCPU, RISCVCPUClass, RISCV_CPU)
380 
381 /**
382  * RISCVCPUClass:
383  * @parent_realize: The parent class' realize handler.
384  * @parent_reset: The parent class' reset handler.
385  *
386  * A RISCV CPU model.
387  */
388 struct RISCVCPUClass {
389     /*< private >*/
390     CPUClass parent_class;
391     /*< public >*/
392     DeviceRealize parent_realize;
393     DeviceReset parent_reset;
394 };
395 
396 struct RISCVCPUConfig {
397     bool ext_i;
398     bool ext_e;
399     bool ext_g;
400     bool ext_m;
401     bool ext_a;
402     bool ext_f;
403     bool ext_d;
404     bool ext_c;
405     bool ext_s;
406     bool ext_u;
407     bool ext_h;
408     bool ext_j;
409     bool ext_v;
410     bool ext_zba;
411     bool ext_zbb;
412     bool ext_zbc;
413     bool ext_zbkb;
414     bool ext_zbkc;
415     bool ext_zbkx;
416     bool ext_zbs;
417     bool ext_zk;
418     bool ext_zkn;
419     bool ext_zknd;
420     bool ext_zkne;
421     bool ext_zknh;
422     bool ext_zkr;
423     bool ext_zks;
424     bool ext_zksed;
425     bool ext_zksh;
426     bool ext_zkt;
427     bool ext_ifencei;
428     bool ext_icsr;
429     bool ext_svinval;
430     bool ext_svnapot;
431     bool ext_svpbmt;
432     bool ext_zdinx;
433     bool ext_zfh;
434     bool ext_zfhmin;
435     bool ext_zfinx;
436     bool ext_zhinx;
437     bool ext_zhinxmin;
438     bool ext_zve32f;
439     bool ext_zve64f;
440     bool ext_zmmul;
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 aia;
462     bool debug;
463     uint64_t resetvec;
464 
465     bool short_isa_string;
466 };
467 
468 typedef struct RISCVCPUConfig RISCVCPUConfig;
469 
470 /**
471  * RISCVCPU:
472  * @env: #CPURISCVState
473  *
474  * A RISCV CPU.
475  */
476 struct ArchCPU {
477     /*< private >*/
478     CPUState parent_obj;
479     /*< public >*/
480     CPUNegativeOffsetState neg;
481     CPURISCVState env;
482 
483     char *dyn_csr_xml;
484     char *dyn_vreg_xml;
485 
486     /* Configuration Settings */
487     RISCVCPUConfig cfg;
488 };
489 
490 static inline int riscv_has_ext(CPURISCVState *env, target_ulong ext)
491 {
492     return (env->misa_ext & ext) != 0;
493 }
494 
495 static inline bool riscv_feature(CPURISCVState *env, int feature)
496 {
497     return env->features & (1ULL << feature);
498 }
499 
500 static inline void riscv_set_feature(CPURISCVState *env, int feature)
501 {
502     env->features |= (1ULL << feature);
503 }
504 
505 #include "cpu_user.h"
506 
507 extern const char * const riscv_int_regnames[];
508 extern const char * const riscv_int_regnamesh[];
509 extern const char * const riscv_fpr_regnames[];
510 
511 const char *riscv_cpu_get_trap_name(target_ulong cause, bool async);
512 void riscv_cpu_do_interrupt(CPUState *cpu);
513 int riscv_cpu_write_elf64_note(WriteCoreDumpFunction f, CPUState *cs,
514                                int cpuid, void *opaque);
515 int riscv_cpu_write_elf32_note(WriteCoreDumpFunction f, CPUState *cs,
516                                int cpuid, void *opaque);
517 int riscv_cpu_gdb_read_register(CPUState *cpu, GByteArray *buf, int reg);
518 int riscv_cpu_gdb_write_register(CPUState *cpu, uint8_t *buf, int reg);
519 int riscv_cpu_hviprio_index2irq(int index, int *out_irq, int *out_rdzero);
520 uint8_t riscv_cpu_default_priority(int irq);
521 uint64_t riscv_cpu_all_pending(CPURISCVState *env);
522 int riscv_cpu_mirq_pending(CPURISCVState *env);
523 int riscv_cpu_sirq_pending(CPURISCVState *env);
524 int riscv_cpu_vsirq_pending(CPURISCVState *env);
525 bool riscv_cpu_fp_enabled(CPURISCVState *env);
526 target_ulong riscv_cpu_get_geilen(CPURISCVState *env);
527 void riscv_cpu_set_geilen(CPURISCVState *env, target_ulong geilen);
528 bool riscv_cpu_vector_enabled(CPURISCVState *env);
529 bool riscv_cpu_virt_enabled(CPURISCVState *env);
530 void riscv_cpu_set_virt_enabled(CPURISCVState *env, bool enable);
531 bool riscv_cpu_two_stage_lookup(int mmu_idx);
532 int riscv_cpu_mmu_index(CPURISCVState *env, bool ifetch);
533 hwaddr riscv_cpu_get_phys_page_debug(CPUState *cpu, vaddr addr);
534 G_NORETURN void  riscv_cpu_do_unaligned_access(CPUState *cs, vaddr addr,
535                                                MMUAccessType access_type, int mmu_idx,
536                                                uintptr_t retaddr);
537 bool riscv_cpu_tlb_fill(CPUState *cs, vaddr address, int size,
538                         MMUAccessType access_type, int mmu_idx,
539                         bool probe, uintptr_t retaddr);
540 void riscv_cpu_do_transaction_failed(CPUState *cs, hwaddr physaddr,
541                                      vaddr addr, unsigned size,
542                                      MMUAccessType access_type,
543                                      int mmu_idx, MemTxAttrs attrs,
544                                      MemTxResult response, uintptr_t retaddr);
545 char *riscv_isa_string(RISCVCPU *cpu);
546 void riscv_cpu_list(void);
547 
548 #define cpu_list riscv_cpu_list
549 #define cpu_mmu_index riscv_cpu_mmu_index
550 
551 #ifndef CONFIG_USER_ONLY
552 bool riscv_cpu_exec_interrupt(CPUState *cs, int interrupt_request);
553 void riscv_cpu_swap_hypervisor_regs(CPURISCVState *env);
554 int riscv_cpu_claim_interrupts(RISCVCPU *cpu, uint64_t interrupts);
555 uint64_t riscv_cpu_update_mip(RISCVCPU *cpu, uint64_t mask, uint64_t value);
556 #define BOOL_TO_MASK(x) (-!!(x)) /* helper for riscv_cpu_update_mip value */
557 void riscv_cpu_set_rdtime_fn(CPURISCVState *env, uint64_t (*fn)(void *),
558                              void *arg);
559 void riscv_cpu_set_aia_ireg_rmw_fn(CPURISCVState *env, uint32_t priv,
560                                    int (*rmw_fn)(void *arg,
561                                                  target_ulong reg,
562                                                  target_ulong *val,
563                                                  target_ulong new_val,
564                                                  target_ulong write_mask),
565                                    void *rmw_fn_arg);
566 #endif
567 void riscv_cpu_set_mode(CPURISCVState *env, target_ulong newpriv);
568 
569 void riscv_translate_init(void);
570 G_NORETURN void riscv_raise_exception(CPURISCVState *env,
571                                       uint32_t exception, uintptr_t pc);
572 
573 target_ulong riscv_cpu_get_fflags(CPURISCVState *env);
574 void riscv_cpu_set_fflags(CPURISCVState *env, target_ulong);
575 
576 #define TB_FLAGS_PRIV_MMU_MASK                3
577 #define TB_FLAGS_PRIV_HYP_ACCESS_MASK   (1 << 2)
578 #define TB_FLAGS_MSTATUS_FS MSTATUS_FS
579 #define TB_FLAGS_MSTATUS_VS MSTATUS_VS
580 
581 #include "exec/cpu-all.h"
582 
583 FIELD(TB_FLAGS, MEM_IDX, 0, 3)
584 FIELD(TB_FLAGS, LMUL, 3, 3)
585 FIELD(TB_FLAGS, SEW, 6, 3)
586 /* Skip MSTATUS_VS (0x600) bits */
587 FIELD(TB_FLAGS, VL_EQ_VLMAX, 11, 1)
588 FIELD(TB_FLAGS, VILL, 12, 1)
589 /* Skip MSTATUS_FS (0x6000) bits */
590 /* Is a Hypervisor instruction load/store allowed? */
591 FIELD(TB_FLAGS, HLSX, 15, 1)
592 FIELD(TB_FLAGS, MSTATUS_HS_FS, 16, 2)
593 FIELD(TB_FLAGS, MSTATUS_HS_VS, 18, 2)
594 /* The combination of MXL/SXL/UXL that applies to the current cpu mode. */
595 FIELD(TB_FLAGS, XL, 20, 2)
596 /* If PointerMasking should be applied */
597 FIELD(TB_FLAGS, PM_MASK_ENABLED, 22, 1)
598 FIELD(TB_FLAGS, PM_BASE_ENABLED, 23, 1)
599 FIELD(TB_FLAGS, VTA, 24, 1)
600 FIELD(TB_FLAGS, VMA, 25, 1)
601 
602 #ifdef TARGET_RISCV32
603 #define riscv_cpu_mxl(env)  ((void)(env), MXL_RV32)
604 #else
605 static inline RISCVMXL riscv_cpu_mxl(CPURISCVState *env)
606 {
607     return env->misa_mxl;
608 }
609 #endif
610 #define riscv_cpu_mxl_bits(env) (1UL << (4 + riscv_cpu_mxl(env)))
611 
612 #if defined(TARGET_RISCV32)
613 #define cpu_recompute_xl(env)  ((void)(env), MXL_RV32)
614 #else
615 static inline RISCVMXL cpu_recompute_xl(CPURISCVState *env)
616 {
617     RISCVMXL xl = env->misa_mxl;
618 #if !defined(CONFIG_USER_ONLY)
619     /*
620      * When emulating a 32-bit-only cpu, use RV32.
621      * When emulating a 64-bit cpu, and MXL has been reduced to RV32,
622      * MSTATUSH doesn't have UXL/SXL, therefore XLEN cannot be widened
623      * back to RV64 for lower privs.
624      */
625     if (xl != MXL_RV32) {
626         switch (env->priv) {
627         case PRV_M:
628             break;
629         case PRV_U:
630             xl = get_field(env->mstatus, MSTATUS64_UXL);
631             break;
632         default: /* PRV_S | PRV_H */
633             xl = get_field(env->mstatus, MSTATUS64_SXL);
634             break;
635         }
636     }
637 #endif
638     return xl;
639 }
640 #endif
641 
642 static inline int riscv_cpu_xlen(CPURISCVState *env)
643 {
644     return 16 << env->xl;
645 }
646 
647 #ifdef TARGET_RISCV32
648 #define riscv_cpu_sxl(env)  ((void)(env), MXL_RV32)
649 #else
650 static inline RISCVMXL riscv_cpu_sxl(CPURISCVState *env)
651 {
652 #ifdef CONFIG_USER_ONLY
653     return env->misa_mxl;
654 #else
655     return get_field(env->mstatus, MSTATUS64_SXL);
656 #endif
657 }
658 #endif
659 
660 /*
661  * Encode LMUL to lmul as follows:
662  *     LMUL    vlmul    lmul
663  *      1       000       0
664  *      2       001       1
665  *      4       010       2
666  *      8       011       3
667  *      -       100       -
668  *     1/8      101      -3
669  *     1/4      110      -2
670  *     1/2      111      -1
671  *
672  * then, we can calculate VLMAX = vlen >> (vsew + 3 - lmul)
673  * e.g. vlen = 256 bits, SEW = 16, LMUL = 1/8
674  *      => VLMAX = vlen >> (1 + 3 - (-3))
675  *               = 256 >> 7
676  *               = 2
677  */
678 static inline uint32_t vext_get_vlmax(RISCVCPU *cpu, target_ulong vtype)
679 {
680     uint8_t sew = FIELD_EX64(vtype, VTYPE, VSEW);
681     int8_t lmul = sextract32(FIELD_EX64(vtype, VTYPE, VLMUL), 0, 3);
682     return cpu->cfg.vlen >> (sew + 3 - lmul);
683 }
684 
685 void cpu_get_tb_cpu_state(CPURISCVState *env, target_ulong *pc,
686                           target_ulong *cs_base, uint32_t *pflags);
687 
688 void riscv_cpu_update_mask(CPURISCVState *env);
689 
690 RISCVException riscv_csrrw(CPURISCVState *env, int csrno,
691                            target_ulong *ret_value,
692                            target_ulong new_value, target_ulong write_mask);
693 RISCVException riscv_csrrw_debug(CPURISCVState *env, int csrno,
694                                  target_ulong *ret_value,
695                                  target_ulong new_value,
696                                  target_ulong write_mask);
697 
698 static inline void riscv_csr_write(CPURISCVState *env, int csrno,
699                                    target_ulong val)
700 {
701     riscv_csrrw(env, csrno, NULL, val, MAKE_64BIT_MASK(0, TARGET_LONG_BITS));
702 }
703 
704 static inline target_ulong riscv_csr_read(CPURISCVState *env, int csrno)
705 {
706     target_ulong val = 0;
707     riscv_csrrw(env, csrno, &val, 0, 0);
708     return val;
709 }
710 
711 typedef RISCVException (*riscv_csr_predicate_fn)(CPURISCVState *env,
712                                                  int csrno);
713 typedef RISCVException (*riscv_csr_read_fn)(CPURISCVState *env, int csrno,
714                                             target_ulong *ret_value);
715 typedef RISCVException (*riscv_csr_write_fn)(CPURISCVState *env, int csrno,
716                                              target_ulong new_value);
717 typedef RISCVException (*riscv_csr_op_fn)(CPURISCVState *env, int csrno,
718                                           target_ulong *ret_value,
719                                           target_ulong new_value,
720                                           target_ulong write_mask);
721 
722 RISCVException riscv_csrrw_i128(CPURISCVState *env, int csrno,
723                                 Int128 *ret_value,
724                                 Int128 new_value, Int128 write_mask);
725 
726 typedef RISCVException (*riscv_csr_read128_fn)(CPURISCVState *env, int csrno,
727                                                Int128 *ret_value);
728 typedef RISCVException (*riscv_csr_write128_fn)(CPURISCVState *env, int csrno,
729                                              Int128 new_value);
730 
731 typedef struct {
732     const char *name;
733     riscv_csr_predicate_fn predicate;
734     riscv_csr_read_fn read;
735     riscv_csr_write_fn write;
736     riscv_csr_op_fn op;
737     riscv_csr_read128_fn read128;
738     riscv_csr_write128_fn write128;
739     /* The default priv spec version should be PRIV_VERSION_1_10_0 (i.e 0) */
740     uint32_t min_priv_ver;
741 } riscv_csr_operations;
742 
743 /* CSR function table constants */
744 enum {
745     CSR_TABLE_SIZE = 0x1000
746 };
747 
748 /* CSR function table */
749 extern riscv_csr_operations csr_ops[CSR_TABLE_SIZE];
750 
751 void riscv_get_csr_ops(int csrno, riscv_csr_operations *ops);
752 void riscv_set_csr_ops(int csrno, riscv_csr_operations *ops);
753 
754 void riscv_cpu_register_gdb_regs_for_features(CPUState *cs);
755 
756 #endif /* RISCV_CPU_H */
757