1 /*
2  * Simple sanity test for emulate_step load/store instructions.
3  *
4  * Copyright IBM Corp. 2016
5  *
6  * This program is free software;  you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  */
11 
12 #define pr_fmt(fmt) "emulate_step_test: " fmt
13 
14 #include <linux/ptrace.h>
15 #include <asm/sstep.h>
16 #include <asm/ppc-opcode.h>
17 
18 #define IMM_L(i)		((uintptr_t)(i) & 0xffff)
19 
20 /*
21  * Defined with TEST_ prefix so it does not conflict with other
22  * definitions.
23  */
24 #define TEST_LD(r, base, i)	(PPC_INST_LD | ___PPC_RT(r) |		\
25 					___PPC_RA(base) | IMM_L(i))
26 #define TEST_LWZ(r, base, i)	(PPC_INST_LWZ | ___PPC_RT(r) |		\
27 					___PPC_RA(base) | IMM_L(i))
28 #define TEST_LWZX(t, a, b)	(PPC_INST_LWZX | ___PPC_RT(t) |		\
29 					___PPC_RA(a) | ___PPC_RB(b))
30 #define TEST_STD(r, base, i)	(PPC_INST_STD | ___PPC_RS(r) |		\
31 					___PPC_RA(base) | ((i) & 0xfffc))
32 #define TEST_LDARX(t, a, b, eh)	(PPC_INST_LDARX | ___PPC_RT(t) |	\
33 					___PPC_RA(a) | ___PPC_RB(b) |	\
34 					__PPC_EH(eh))
35 #define TEST_STDCX(s, a, b)	(PPC_INST_STDCX | ___PPC_RS(s) |	\
36 					___PPC_RA(a) | ___PPC_RB(b))
37 #define TEST_LFSX(t, a, b)	(PPC_INST_LFSX | ___PPC_RT(t) |		\
38 					___PPC_RA(a) | ___PPC_RB(b))
39 #define TEST_STFSX(s, a, b)	(PPC_INST_STFSX | ___PPC_RS(s) |	\
40 					___PPC_RA(a) | ___PPC_RB(b))
41 #define TEST_LFDX(t, a, b)	(PPC_INST_LFDX | ___PPC_RT(t) |		\
42 					___PPC_RA(a) | ___PPC_RB(b))
43 #define TEST_STFDX(s, a, b)	(PPC_INST_STFDX | ___PPC_RS(s) |	\
44 					___PPC_RA(a) | ___PPC_RB(b))
45 #define TEST_LVX(t, a, b)	(PPC_INST_LVX | ___PPC_RT(t) |		\
46 					___PPC_RA(a) | ___PPC_RB(b))
47 #define TEST_STVX(s, a, b)	(PPC_INST_STVX | ___PPC_RS(s) |		\
48 					___PPC_RA(a) | ___PPC_RB(b))
49 #define TEST_LXVD2X(s, a, b)	(PPC_INST_LXVD2X | VSX_XX1((s), R##a, R##b))
50 #define TEST_STXVD2X(s, a, b)	(PPC_INST_STXVD2X | VSX_XX1((s), R##a, R##b))
51 
52 
53 static void __init init_pt_regs(struct pt_regs *regs)
54 {
55 	static unsigned long msr;
56 	static bool msr_cached;
57 
58 	memset(regs, 0, sizeof(struct pt_regs));
59 
60 	if (likely(msr_cached)) {
61 		regs->msr = msr;
62 		return;
63 	}
64 
65 	asm volatile("mfmsr %0" : "=r"(regs->msr));
66 
67 	regs->msr |= MSR_FP;
68 	regs->msr |= MSR_VEC;
69 	regs->msr |= MSR_VSX;
70 
71 	msr = regs->msr;
72 	msr_cached = true;
73 }
74 
75 static void __init show_result(char *ins, char *result)
76 {
77 	pr_info("%-14s : %s\n", ins, result);
78 }
79 
80 static void __init test_ld(void)
81 {
82 	struct pt_regs regs;
83 	unsigned long a = 0x23;
84 	int stepped = -1;
85 
86 	init_pt_regs(&regs);
87 	regs.gpr[3] = (unsigned long) &a;
88 
89 	/* ld r5, 0(r3) */
90 	stepped = emulate_step(&regs, TEST_LD(5, 3, 0));
91 
92 	if (stepped == 1 && regs.gpr[5] == a)
93 		show_result("ld", "PASS");
94 	else
95 		show_result("ld", "FAIL");
96 }
97 
98 static void __init test_lwz(void)
99 {
100 	struct pt_regs regs;
101 	unsigned int a = 0x4545;
102 	int stepped = -1;
103 
104 	init_pt_regs(&regs);
105 	regs.gpr[3] = (unsigned long) &a;
106 
107 	/* lwz r5, 0(r3) */
108 	stepped = emulate_step(&regs, TEST_LWZ(5, 3, 0));
109 
110 	if (stepped == 1 && regs.gpr[5] == a)
111 		show_result("lwz", "PASS");
112 	else
113 		show_result("lwz", "FAIL");
114 }
115 
116 static void __init test_lwzx(void)
117 {
118 	struct pt_regs regs;
119 	unsigned int a[3] = {0x0, 0x0, 0x1234};
120 	int stepped = -1;
121 
122 	init_pt_regs(&regs);
123 	regs.gpr[3] = (unsigned long) a;
124 	regs.gpr[4] = 8;
125 	regs.gpr[5] = 0x8765;
126 
127 	/* lwzx r5, r3, r4 */
128 	stepped = emulate_step(&regs, TEST_LWZX(5, 3, 4));
129 	if (stepped == 1 && regs.gpr[5] == a[2])
130 		show_result("lwzx", "PASS");
131 	else
132 		show_result("lwzx", "FAIL");
133 }
134 
135 static void __init test_std(void)
136 {
137 	struct pt_regs regs;
138 	unsigned long a = 0x1234;
139 	int stepped = -1;
140 
141 	init_pt_regs(&regs);
142 	regs.gpr[3] = (unsigned long) &a;
143 	regs.gpr[5] = 0x5678;
144 
145 	/* std r5, 0(r3) */
146 	stepped = emulate_step(&regs, TEST_STD(5, 3, 0));
147 	if (stepped == 1 || regs.gpr[5] == a)
148 		show_result("std", "PASS");
149 	else
150 		show_result("std", "FAIL");
151 }
152 
153 static void __init test_ldarx_stdcx(void)
154 {
155 	struct pt_regs regs;
156 	unsigned long a = 0x1234;
157 	int stepped = -1;
158 	unsigned long cr0_eq = 0x1 << 29; /* eq bit of CR0 */
159 
160 	init_pt_regs(&regs);
161 	asm volatile("mfcr %0" : "=r"(regs.ccr));
162 
163 
164 	/*** ldarx ***/
165 
166 	regs.gpr[3] = (unsigned long) &a;
167 	regs.gpr[4] = 0;
168 	regs.gpr[5] = 0x5678;
169 
170 	/* ldarx r5, r3, r4, 0 */
171 	stepped = emulate_step(&regs, TEST_LDARX(5, 3, 4, 0));
172 
173 	/*
174 	 * Don't touch 'a' here. Touching 'a' can do Load/store
175 	 * of 'a' which result in failure of subsequent stdcx.
176 	 * Instead, use hardcoded value for comparison.
177 	 */
178 	if (stepped <= 0 || regs.gpr[5] != 0x1234) {
179 		show_result("ldarx / stdcx.", "FAIL (ldarx)");
180 		return;
181 	}
182 
183 
184 	/*** stdcx. ***/
185 
186 	regs.gpr[5] = 0x9ABC;
187 
188 	/* stdcx. r5, r3, r4 */
189 	stepped = emulate_step(&regs, TEST_STDCX(5, 3, 4));
190 
191 	/*
192 	 * Two possible scenarios that indicates successful emulation
193 	 * of stdcx. :
194 	 *  1. Reservation is active and store is performed. In this
195 	 *     case cr0.eq bit will be set to 1.
196 	 *  2. Reservation is not active and store is not performed.
197 	 *     In this case cr0.eq bit will be set to 0.
198 	 */
199 	if (stepped == 1 && ((regs.gpr[5] == a && (regs.ccr & cr0_eq))
200 			|| (regs.gpr[5] != a && !(regs.ccr & cr0_eq))))
201 		show_result("ldarx / stdcx.", "PASS");
202 	else
203 		show_result("ldarx / stdcx.", "FAIL (stdcx.)");
204 }
205 
206 #ifdef CONFIG_PPC_FPU
207 static void __init test_lfsx_stfsx(void)
208 {
209 	struct pt_regs regs;
210 	union {
211 		float a;
212 		int b;
213 	} c;
214 	int cached_b;
215 	int stepped = -1;
216 
217 	init_pt_regs(&regs);
218 
219 
220 	/*** lfsx ***/
221 
222 	c.a = 123.45;
223 	cached_b = c.b;
224 
225 	regs.gpr[3] = (unsigned long) &c.a;
226 	regs.gpr[4] = 0;
227 
228 	/* lfsx frt10, r3, r4 */
229 	stepped = emulate_step(&regs, TEST_LFSX(10, 3, 4));
230 
231 	if (stepped == 1)
232 		show_result("lfsx", "PASS");
233 	else
234 		show_result("lfsx", "FAIL");
235 
236 
237 	/*** stfsx ***/
238 
239 	c.a = 678.91;
240 
241 	/* stfsx frs10, r3, r4 */
242 	stepped = emulate_step(&regs, TEST_STFSX(10, 3, 4));
243 
244 	if (stepped == 1 && c.b == cached_b)
245 		show_result("stfsx", "PASS");
246 	else
247 		show_result("stfsx", "FAIL");
248 }
249 
250 static void __init test_lfdx_stfdx(void)
251 {
252 	struct pt_regs regs;
253 	union {
254 		double a;
255 		long b;
256 	} c;
257 	long cached_b;
258 	int stepped = -1;
259 
260 	init_pt_regs(&regs);
261 
262 
263 	/*** lfdx ***/
264 
265 	c.a = 123456.78;
266 	cached_b = c.b;
267 
268 	regs.gpr[3] = (unsigned long) &c.a;
269 	regs.gpr[4] = 0;
270 
271 	/* lfdx frt10, r3, r4 */
272 	stepped = emulate_step(&regs, TEST_LFDX(10, 3, 4));
273 
274 	if (stepped == 1)
275 		show_result("lfdx", "PASS");
276 	else
277 		show_result("lfdx", "FAIL");
278 
279 
280 	/*** stfdx ***/
281 
282 	c.a = 987654.32;
283 
284 	/* stfdx frs10, r3, r4 */
285 	stepped = emulate_step(&regs, TEST_STFDX(10, 3, 4));
286 
287 	if (stepped == 1 && c.b == cached_b)
288 		show_result("stfdx", "PASS");
289 	else
290 		show_result("stfdx", "FAIL");
291 }
292 #else
293 static void __init test_lfsx_stfsx(void)
294 {
295 	show_result("lfsx", "SKIP (CONFIG_PPC_FPU is not set)");
296 	show_result("stfsx", "SKIP (CONFIG_PPC_FPU is not set)");
297 }
298 
299 static void __init test_lfdx_stfdx(void)
300 {
301 	show_result("lfdx", "SKIP (CONFIG_PPC_FPU is not set)");
302 	show_result("stfdx", "SKIP (CONFIG_PPC_FPU is not set)");
303 }
304 #endif /* CONFIG_PPC_FPU */
305 
306 #ifdef CONFIG_ALTIVEC
307 static void __init test_lvx_stvx(void)
308 {
309 	struct pt_regs regs;
310 	union {
311 		vector128 a;
312 		u32 b[4];
313 	} c;
314 	u32 cached_b[4];
315 	int stepped = -1;
316 
317 	init_pt_regs(&regs);
318 
319 
320 	/*** lvx ***/
321 
322 	cached_b[0] = c.b[0] = 923745;
323 	cached_b[1] = c.b[1] = 2139478;
324 	cached_b[2] = c.b[2] = 9012;
325 	cached_b[3] = c.b[3] = 982134;
326 
327 	regs.gpr[3] = (unsigned long) &c.a;
328 	regs.gpr[4] = 0;
329 
330 	/* lvx vrt10, r3, r4 */
331 	stepped = emulate_step(&regs, TEST_LVX(10, 3, 4));
332 
333 	if (stepped == 1)
334 		show_result("lvx", "PASS");
335 	else
336 		show_result("lvx", "FAIL");
337 
338 
339 	/*** stvx ***/
340 
341 	c.b[0] = 4987513;
342 	c.b[1] = 84313948;
343 	c.b[2] = 71;
344 	c.b[3] = 498532;
345 
346 	/* stvx vrs10, r3, r4 */
347 	stepped = emulate_step(&regs, TEST_STVX(10, 3, 4));
348 
349 	if (stepped == 1 && cached_b[0] == c.b[0] && cached_b[1] == c.b[1] &&
350 	    cached_b[2] == c.b[2] && cached_b[3] == c.b[3])
351 		show_result("stvx", "PASS");
352 	else
353 		show_result("stvx", "FAIL");
354 }
355 #else
356 static void __init test_lvx_stvx(void)
357 {
358 	show_result("lvx", "SKIP (CONFIG_ALTIVEC is not set)");
359 	show_result("stvx", "SKIP (CONFIG_ALTIVEC is not set)");
360 }
361 #endif /* CONFIG_ALTIVEC */
362 
363 #ifdef CONFIG_VSX
364 static void __init test_lxvd2x_stxvd2x(void)
365 {
366 	struct pt_regs regs;
367 	union {
368 		vector128 a;
369 		u32 b[4];
370 	} c;
371 	u32 cached_b[4];
372 	int stepped = -1;
373 
374 	init_pt_regs(&regs);
375 
376 
377 	/*** lxvd2x ***/
378 
379 	cached_b[0] = c.b[0] = 18233;
380 	cached_b[1] = c.b[1] = 34863571;
381 	cached_b[2] = c.b[2] = 834;
382 	cached_b[3] = c.b[3] = 6138911;
383 
384 	regs.gpr[3] = (unsigned long) &c.a;
385 	regs.gpr[4] = 0;
386 
387 	/* lxvd2x vsr39, r3, r4 */
388 	stepped = emulate_step(&regs, TEST_LXVD2X(39, 3, 4));
389 
390 	if (stepped == 1)
391 		show_result("lxvd2x", "PASS");
392 	else
393 		show_result("lxvd2x", "FAIL");
394 
395 
396 	/*** stxvd2x ***/
397 
398 	c.b[0] = 21379463;
399 	c.b[1] = 87;
400 	c.b[2] = 374234;
401 	c.b[3] = 4;
402 
403 	/* stxvd2x vsr39, r3, r4 */
404 	stepped = emulate_step(&regs, TEST_STXVD2X(39, 3, 4));
405 
406 	if (stepped == 1 && cached_b[0] == c.b[0] && cached_b[1] == c.b[1] &&
407 	    cached_b[2] == c.b[2] && cached_b[3] == c.b[3])
408 		show_result("stxvd2x", "PASS");
409 	else
410 		show_result("stxvd2x", "FAIL");
411 }
412 #else
413 static void __init test_lxvd2x_stxvd2x(void)
414 {
415 	show_result("lxvd2x", "SKIP (CONFIG_VSX is not set)");
416 	show_result("stxvd2x", "SKIP (CONFIG_VSX is not set)");
417 }
418 #endif /* CONFIG_VSX */
419 
420 static int __init test_emulate_step(void)
421 {
422 	test_ld();
423 	test_lwz();
424 	test_lwzx();
425 	test_std();
426 	test_ldarx_stdcx();
427 	test_lfsx_stfsx();
428 	test_lfdx_stfdx();
429 	test_lvx_stvx();
430 	test_lxvd2x_stxvd2x();
431 
432 	return 0;
433 }
434 late_initcall(test_emulate_step);
435