xref: /llvm-project/compiler-rt/lib/builtins/cpu_model/riscv.c (revision 522880cb99b0573d8689eee083b28af18ff3f9c2)
1 //=== cpu_model/riscv.c - Update RISC-V Feature Bits Structure -*- C -*-======//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 
9 #include "cpu_model.h"
10 
11 #define RISCV_FEATURE_BITS_LENGTH 2
12 struct {
13   unsigned length;
14   unsigned long long features[RISCV_FEATURE_BITS_LENGTH];
15 } __riscv_feature_bits __attribute__((visibility("hidden"), nocommon));
16 
17 #define RISCV_VENDOR_FEATURE_BITS_LENGTH 1
18 struct {
19   unsigned length;
20   unsigned long long features[RISCV_VENDOR_FEATURE_BITS_LENGTH];
21 } __riscv_vendor_feature_bits __attribute__((visibility("hidden"), nocommon));
22 
23 struct {
24   unsigned mvendorid;
25   unsigned long long marchid;
26   unsigned long long mimpid;
27 } __riscv_cpu_model __attribute__((visibility("hidden"), nocommon));
28 
29 // NOTE: Should sync-up with RISCVFeatures.td
30 // TODO: Maybe generate a header from tablegen then include it.
31 #define A_GROUPID 0
32 #define A_BITMASK (1ULL << 0)
33 #define C_GROUPID 0
34 #define C_BITMASK (1ULL << 2)
35 #define D_GROUPID 0
36 #define D_BITMASK (1ULL << 3)
37 #define F_GROUPID 0
38 #define F_BITMASK (1ULL << 5)
39 #define I_GROUPID 0
40 #define I_BITMASK (1ULL << 8)
41 #define M_GROUPID 0
42 #define M_BITMASK (1ULL << 12)
43 #define V_GROUPID 0
44 #define V_BITMASK (1ULL << 21)
45 #define ZACAS_GROUPID 0
46 #define ZACAS_BITMASK (1ULL << 26)
47 #define ZBA_GROUPID 0
48 #define ZBA_BITMASK (1ULL << 27)
49 #define ZBB_GROUPID 0
50 #define ZBB_BITMASK (1ULL << 28)
51 #define ZBC_GROUPID 0
52 #define ZBC_BITMASK (1ULL << 29)
53 #define ZBKB_GROUPID 0
54 #define ZBKB_BITMASK (1ULL << 30)
55 #define ZBKC_GROUPID 0
56 #define ZBKC_BITMASK (1ULL << 31)
57 #define ZBKX_GROUPID 0
58 #define ZBKX_BITMASK (1ULL << 32)
59 #define ZBS_GROUPID 0
60 #define ZBS_BITMASK (1ULL << 33)
61 #define ZFA_GROUPID 0
62 #define ZFA_BITMASK (1ULL << 34)
63 #define ZFH_GROUPID 0
64 #define ZFH_BITMASK (1ULL << 35)
65 #define ZFHMIN_GROUPID 0
66 #define ZFHMIN_BITMASK (1ULL << 36)
67 #define ZICBOZ_GROUPID 0
68 #define ZICBOZ_BITMASK (1ULL << 37)
69 #define ZICOND_GROUPID 0
70 #define ZICOND_BITMASK (1ULL << 38)
71 #define ZIHINTNTL_GROUPID 0
72 #define ZIHINTNTL_BITMASK (1ULL << 39)
73 #define ZIHINTPAUSE_GROUPID 0
74 #define ZIHINTPAUSE_BITMASK (1ULL << 40)
75 #define ZKND_GROUPID 0
76 #define ZKND_BITMASK (1ULL << 41)
77 #define ZKNE_GROUPID 0
78 #define ZKNE_BITMASK (1ULL << 42)
79 #define ZKNH_GROUPID 0
80 #define ZKNH_BITMASK (1ULL << 43)
81 #define ZKSED_GROUPID 0
82 #define ZKSED_BITMASK (1ULL << 44)
83 #define ZKSH_GROUPID 0
84 #define ZKSH_BITMASK (1ULL << 45)
85 #define ZKT_GROUPID 0
86 #define ZKT_BITMASK (1ULL << 46)
87 #define ZTSO_GROUPID 0
88 #define ZTSO_BITMASK (1ULL << 47)
89 #define ZVBB_GROUPID 0
90 #define ZVBB_BITMASK (1ULL << 48)
91 #define ZVBC_GROUPID 0
92 #define ZVBC_BITMASK (1ULL << 49)
93 #define ZVFH_GROUPID 0
94 #define ZVFH_BITMASK (1ULL << 50)
95 #define ZVFHMIN_GROUPID 0
96 #define ZVFHMIN_BITMASK (1ULL << 51)
97 #define ZVKB_GROUPID 0
98 #define ZVKB_BITMASK (1ULL << 52)
99 #define ZVKG_GROUPID 0
100 #define ZVKG_BITMASK (1ULL << 53)
101 #define ZVKNED_GROUPID 0
102 #define ZVKNED_BITMASK (1ULL << 54)
103 #define ZVKNHA_GROUPID 0
104 #define ZVKNHA_BITMASK (1ULL << 55)
105 #define ZVKNHB_GROUPID 0
106 #define ZVKNHB_BITMASK (1ULL << 56)
107 #define ZVKSED_GROUPID 0
108 #define ZVKSED_BITMASK (1ULL << 57)
109 #define ZVKSH_GROUPID 0
110 #define ZVKSH_BITMASK (1ULL << 58)
111 #define ZVKT_GROUPID 0
112 #define ZVKT_BITMASK (1ULL << 59)
113 #define ZVE32X_GROUPID 0
114 #define ZVE32X_BITMASK (1ULL << 60)
115 #define ZVE32F_GROUPID 0
116 #define ZVE32F_BITMASK (1ULL << 61)
117 #define ZVE64X_GROUPID 0
118 #define ZVE64X_BITMASK (1ULL << 62)
119 #define ZVE64F_GROUPID 0
120 #define ZVE64F_BITMASK (1ULL << 63)
121 #define ZVE64D_GROUPID 1
122 #define ZVE64D_BITMASK (1ULL << 0)
123 #define ZIMOP_GROUPID 1
124 #define ZIMOP_BITMASK (1ULL << 1)
125 #define ZCA_GROUPID 1
126 #define ZCA_BITMASK (1ULL << 2)
127 #define ZCB_GROUPID 1
128 #define ZCB_BITMASK (1ULL << 3)
129 #define ZCD_GROUPID 1
130 #define ZCD_BITMASK (1ULL << 4)
131 #define ZCF_GROUPID 1
132 #define ZCF_BITMASK (1ULL << 5)
133 #define ZCMOP_GROUPID 1
134 #define ZCMOP_BITMASK (1ULL << 6)
135 #define ZAWRS_GROUPID 1
136 #define ZAWRS_BITMASK (1ULL << 7)
137 
138 #if defined(__linux__)
139 
140 // The RISC-V hwprobe interface is documented here:
141 // <https://docs.kernel.org/arch/riscv/hwprobe.html>.
142 
143 static long syscall_impl_5_args(long number, long arg1, long arg2, long arg3,
144                                 long arg4, long arg5) {
145   register long a7 __asm__("a7") = number;
146   register long a0 __asm__("a0") = arg1;
147   register long a1 __asm__("a1") = arg2;
148   register long a2 __asm__("a2") = arg3;
149   register long a3 __asm__("a3") = arg4;
150   register long a4 __asm__("a4") = arg5;
151   __asm__ __volatile__("ecall\n\t"
152                        : "=r"(a0)
153                        : "r"(a7), "r"(a0), "r"(a1), "r"(a2), "r"(a3), "r"(a4)
154                        : "memory");
155   return a0;
156 }
157 
158 #define RISCV_HWPROBE_KEY_MVENDORID 0
159 #define RISCV_HWPROBE_KEY_MARCHID 1
160 #define RISCV_HWPROBE_KEY_MIMPID 2
161 #define RISCV_HWPROBE_KEY_BASE_BEHAVIOR 3
162 #define RISCV_HWPROBE_BASE_BEHAVIOR_IMA (1ULL << 0)
163 #define RISCV_HWPROBE_KEY_IMA_EXT_0 4
164 #define RISCV_HWPROBE_IMA_FD (1ULL << 0)
165 #define RISCV_HWPROBE_IMA_C (1ULL << 1)
166 #define RISCV_HWPROBE_IMA_V (1ULL << 2)
167 #define RISCV_HWPROBE_EXT_ZBA (1ULL << 3)
168 #define RISCV_HWPROBE_EXT_ZBB (1ULL << 4)
169 #define RISCV_HWPROBE_EXT_ZBS (1ULL << 5)
170 #define RISCV_HWPROBE_EXT_ZICBOZ (1ULL << 6)
171 #define RISCV_HWPROBE_EXT_ZBC (1ULL << 7)
172 #define RISCV_HWPROBE_EXT_ZBKB (1ULL << 8)
173 #define RISCV_HWPROBE_EXT_ZBKC (1ULL << 9)
174 #define RISCV_HWPROBE_EXT_ZBKX (1ULL << 10)
175 #define RISCV_HWPROBE_EXT_ZKND (1ULL << 11)
176 #define RISCV_HWPROBE_EXT_ZKNE (1ULL << 12)
177 #define RISCV_HWPROBE_EXT_ZKNH (1ULL << 13)
178 #define RISCV_HWPROBE_EXT_ZKSED (1ULL << 14)
179 #define RISCV_HWPROBE_EXT_ZKSH (1ULL << 15)
180 #define RISCV_HWPROBE_EXT_ZKT (1ULL << 16)
181 #define RISCV_HWPROBE_EXT_ZVBB (1ULL << 17)
182 #define RISCV_HWPROBE_EXT_ZVBC (1ULL << 18)
183 #define RISCV_HWPROBE_EXT_ZVKB (1ULL << 19)
184 #define RISCV_HWPROBE_EXT_ZVKG (1ULL << 20)
185 #define RISCV_HWPROBE_EXT_ZVKNED (1ULL << 21)
186 #define RISCV_HWPROBE_EXT_ZVKNHA (1ULL << 22)
187 #define RISCV_HWPROBE_EXT_ZVKNHB (1ULL << 23)
188 #define RISCV_HWPROBE_EXT_ZVKSED (1ULL << 24)
189 #define RISCV_HWPROBE_EXT_ZVKSH (1ULL << 25)
190 #define RISCV_HWPROBE_EXT_ZVKT (1ULL << 26)
191 #define RISCV_HWPROBE_EXT_ZFH (1ULL << 27)
192 #define RISCV_HWPROBE_EXT_ZFHMIN (1ULL << 28)
193 #define RISCV_HWPROBE_EXT_ZIHINTNTL (1ULL << 29)
194 #define RISCV_HWPROBE_EXT_ZVFH (1ULL << 30)
195 #define RISCV_HWPROBE_EXT_ZVFHMIN (1ULL << 31)
196 #define RISCV_HWPROBE_EXT_ZFA (1ULL << 32)
197 #define RISCV_HWPROBE_EXT_ZTSO (1ULL << 33)
198 #define RISCV_HWPROBE_EXT_ZACAS (1ULL << 34)
199 #define RISCV_HWPROBE_EXT_ZICOND (1ULL << 35)
200 #define RISCV_HWPROBE_EXT_ZIHINTPAUSE (1ULL << 36)
201 #define RISCV_HWPROBE_EXT_ZVE32X (1ULL << 37)
202 #define RISCV_HWPROBE_EXT_ZVE32F (1ULL << 38)
203 #define RISCV_HWPROBE_EXT_ZVE64X (1ULL << 39)
204 #define RISCV_HWPROBE_EXT_ZVE64F (1ULL << 40)
205 #define RISCV_HWPROBE_EXT_ZVE64D (1ULL << 41)
206 #define RISCV_HWPROBE_EXT_ZIMOP (1ULL << 42)
207 #define RISCV_HWPROBE_EXT_ZCA (1ULL << 43)
208 #define RISCV_HWPROBE_EXT_ZCB (1ULL << 44)
209 #define RISCV_HWPROBE_EXT_ZCD (1ULL << 45)
210 #define RISCV_HWPROBE_EXT_ZCF (1ULL << 46)
211 #define RISCV_HWPROBE_EXT_ZCMOP (1ULL << 47)
212 #define RISCV_HWPROBE_EXT_ZAWRS (1ULL << 48)
213 #define RISCV_HWPROBE_KEY_CPUPERF_0 5
214 #define RISCV_HWPROBE_MISALIGNED_UNKNOWN (0 << 0)
215 #define RISCV_HWPROBE_MISALIGNED_EMULATED (1ULL << 0)
216 #define RISCV_HWPROBE_MISALIGNED_SLOW (2 << 0)
217 #define RISCV_HWPROBE_MISALIGNED_FAST (3 << 0)
218 #define RISCV_HWPROBE_MISALIGNED_UNSUPPORTED (4 << 0)
219 #define RISCV_HWPROBE_MISALIGNED_MASK (7 << 0)
220 #define RISCV_HWPROBE_KEY_ZICBOZ_BLOCK_SIZE 6
221 /* Increase RISCV_HWPROBE_MAX_KEY when adding items. */
222 
223 struct riscv_hwprobe {
224   long long key;
225   unsigned long long value;
226 };
227 
228 #define __NR_riscv_hwprobe 258
229 static long initHwProbe(struct riscv_hwprobe *Hwprobes, int len) {
230   return syscall_impl_5_args(__NR_riscv_hwprobe, (long)Hwprobes, len, 0, 0, 0);
231 }
232 
233 #define SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(EXTNAME)                    \
234   SET_SINGLE_IMAEXT_RISCV_FEATURE(RISCV_HWPROBE_EXT_##EXTNAME, EXTNAME)
235 
236 #define SET_SINGLE_IMAEXT_RISCV_FEATURE(HWPROBE_BITMASK, EXT)                  \
237   SET_SINGLE_RISCV_FEATURE(IMAEXT0Value &HWPROBE_BITMASK, EXT)
238 
239 #define SET_SINGLE_RISCV_FEATURE(COND, EXT)                                    \
240   if (COND) {                                                                  \
241     SET_RISCV_FEATURE(EXT);                                                    \
242   }
243 
244 #define SET_RISCV_FEATURE(EXT) features[EXT##_GROUPID] |= EXT##_BITMASK
245 
246 static void initRISCVFeature(struct riscv_hwprobe Hwprobes[]) {
247 
248   // Note: If a hwprobe key is unknown to the kernel, its key field
249   // will be cleared to -1, and its value set to 0.
250   // This unsets all extension bitmask bits.
251 
252   // Init VendorID, ArchID, ImplID
253   __riscv_cpu_model.mvendorid = Hwprobes[2].value;
254   __riscv_cpu_model.marchid = Hwprobes[3].value;
255   __riscv_cpu_model.mimpid = Hwprobes[4].value;
256 
257   // Init standard extension
258   // TODO: Maybe Extension implied generate from tablegen?
259 
260   unsigned long long features[RISCV_FEATURE_BITS_LENGTH];
261   int i;
262 
263   for (i = 0; i < RISCV_FEATURE_BITS_LENGTH; i++)
264     features[i] = 0;
265 
266   // Check RISCV_HWPROBE_KEY_BASE_BEHAVIOR
267   unsigned long long BaseValue = Hwprobes[0].value;
268   if (BaseValue & RISCV_HWPROBE_BASE_BEHAVIOR_IMA) {
269     SET_RISCV_FEATURE(I);
270     SET_RISCV_FEATURE(M);
271     SET_RISCV_FEATURE(A);
272   }
273 
274   // Check RISCV_HWPROBE_KEY_IMA_EXT_0
275   unsigned long long IMAEXT0Value = Hwprobes[1].value;
276   if (IMAEXT0Value & RISCV_HWPROBE_IMA_FD) {
277     SET_RISCV_FEATURE(F);
278     SET_RISCV_FEATURE(D);
279   }
280 
281   SET_SINGLE_IMAEXT_RISCV_FEATURE(RISCV_HWPROBE_IMA_C, C);
282   SET_SINGLE_IMAEXT_RISCV_FEATURE(RISCV_HWPROBE_IMA_V, V);
283   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZBA);
284   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZBB);
285   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZBS);
286   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZICBOZ);
287   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZBC);
288   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZBKB);
289   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZBKC);
290   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZBKX);
291   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZKND);
292   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZKNE);
293   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZKNH);
294   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZKSED);
295   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZKSH);
296   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZKT);
297   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZVBB);
298   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZVBC);
299   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZVKB);
300   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZVKG);
301   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZVKNED);
302   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZVKNHA);
303   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZVKNHB);
304   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZVKSED);
305   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZVKSH);
306   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZVKT);
307   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZFH);
308   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZFHMIN);
309   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZIHINTNTL);
310   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZIHINTPAUSE);
311   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZVFH);
312   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZVFHMIN);
313   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZFA);
314   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZTSO);
315   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZACAS);
316   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZICOND);
317   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZVE32X);
318   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZVE32F);
319   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZVE64X);
320   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZVE64F);
321   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZVE64D);
322   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZIMOP);
323   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZCA);
324   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZCB);
325   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZCD);
326   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZCF);
327   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZCMOP);
328   SET_RISCV_HWPROBE_EXT_SINGLE_RISCV_FEATURE(ZAWRS);
329 
330   for (i = 0; i < RISCV_FEATURE_BITS_LENGTH; i++)
331     __riscv_feature_bits.features[i] = features[i];
332 }
333 
334 #endif // defined(__linux__)
335 
336 static int FeaturesBitCached = 0;
337 
338 void __init_riscv_feature_bits(void *);
339 static void __init_riscv_feature_bits_ctor(void) CONSTRUCTOR_ATTRIBUTE;
340 
341 // A constructor function that sets __riscv_feature_bits, and
342 // __riscv_vendor_feature_bits to the right values.  This needs to run
343 // only once.  This constructor is given the highest priority and it should
344 // run before constructors without the priority set.  However, it still runs
345 // after ifunc initializers and needs to be called explicitly there.
346 
347 static void CONSTRUCTOR_ATTRIBUTE __init_riscv_feature_bits_ctor(void) {
348   __init_riscv_feature_bits(0);
349 }
350 
351 // PlatformArgs allows the platform to provide pre-computed data and access it
352 // without extra effort. For example, Linux could pass the vDSO object to avoid
353 // an extra system call.
354 void __init_riscv_feature_bits(void *PlatformArgs) {
355 
356   if (FeaturesBitCached)
357     return;
358 
359   __riscv_feature_bits.length = RISCV_FEATURE_BITS_LENGTH;
360   __riscv_vendor_feature_bits.length = RISCV_VENDOR_FEATURE_BITS_LENGTH;
361 
362 #if defined(__linux__)
363   struct riscv_hwprobe Hwprobes[] = {
364       {RISCV_HWPROBE_KEY_BASE_BEHAVIOR, 0}, {RISCV_HWPROBE_KEY_IMA_EXT_0, 0},
365       {RISCV_HWPROBE_KEY_MVENDORID, 0},     {RISCV_HWPROBE_KEY_MARCHID, 0},
366       {RISCV_HWPROBE_KEY_MIMPID, 0},
367   };
368   if (initHwProbe(Hwprobes, sizeof(Hwprobes) / sizeof(Hwprobes[0])))
369     return;
370 
371   initRISCVFeature(Hwprobes);
372 #endif // defined(__linux__)
373 
374   FeaturesBitCached = 1;
375 }
376