1/* SPDX-License-Identifier: GPL-2.0-or-later */
2/*
3 * This file contains miscellaneous low-level functions.
4 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
5 *
6 * Largely rewritten by Cort Dougan (cort@cs.nmt.edu)
7 * and Paul Mackerras.
8 *
9 */
10
11#include <linux/export.h>
12#include <linux/sys.h>
13#include <asm/unistd.h>
14#include <asm/errno.h>
15#include <asm/reg.h>
16#include <asm/page.h>
17#include <asm/cache.h>
18#include <asm/cputable.h>
19#include <asm/mmu.h>
20#include <asm/ppc_asm.h>
21#include <asm/thread_info.h>
22#include <asm/asm-offsets.h>
23#include <asm/processor.h>
24#include <asm/bug.h>
25#include <asm/ptrace.h>
26#include <asm/feature-fixups.h>
27
28 .text
29
30/*
31 * This returns the high 64 bits of the product of two 64-bit numbers.
32 */
33_GLOBAL(mulhdu)
34 cmpwi r6,0
35 cmpwi cr1,r3,0
36 mr r10,r4
37 mulhwu r4,r4,r5
38 beq 1f
39 mulhwu r0,r10,r6
40 mullw r7,r10,r5
41 addc r7,r0,r7
42 addze r4,r4
431: beqlr cr1 /* all done if high part of A is 0 */
44 mullw r9,r3,r5
45 mulhwu r10,r3,r5
46 beq 2f
47 mullw r0,r3,r6
48 mulhwu r8,r3,r6
49 addc r7,r0,r7
50 adde r4,r4,r8
51 addze r10,r10
522: addc r4,r4,r9
53 addze r3,r10
54 blr
55
56/*
57 * reloc_got2 runs through the .got2 section adding an offset
58 * to each entry.
59 */
60_GLOBAL(reloc_got2)
61 mflr r11
62 lis r7,__got2_start@ha
63 addi r7,r7,__got2_start@l
64 lis r8,__got2_end@ha
65 addi r8,r8,__got2_end@l
66 subf r8,r7,r8
67 srwi. r8,r8,2
68 beqlr
69 mtctr r8
70 bcl 20,31,$+4
711: mflr r0
72 lis r4,1b@ha
73 addi r4,r4,1b@l
74 subf r0,r4,r0
75 add r7,r0,r7
762: lwz r0,0(r7)
77 add r0,r0,r3
78 stw r0,0(r7)
79 addi r7,r7,4
80 bdnz 2b
81 mtlr r11
82 blr
83
84/*
85 * call_setup_cpu - call the setup_cpu function for this cpu
86 * r3 = data offset, r24 = cpu number
87 *
88 * Setup function is called with:
89 * r3 = data offset
90 * r4 = ptr to CPU spec (relocated)
91 */
92_GLOBAL(call_setup_cpu)
93 addis r4,r3,cur_cpu_spec@ha
94 addi r4,r4,cur_cpu_spec@l
95 lwz r4,0(r4)
96 add r4,r4,r3
97 lwz r5,CPU_SPEC_SETUP(r4)
98 cmpwi 0,r5,0
99 add r5,r5,r3
100 beqlr
101 mtctr r5
102 bctr
103
104#if defined(CONFIG_CPU_FREQ_PMAC) && defined(CONFIG_PPC_BOOK3S_32)
105
106/* This gets called by via-pmu.c to switch the PLL selection
107 * on 750fx CPU. This function should really be moved to some
108 * other place (as most of the cpufreq code in via-pmu
109 */
110_GLOBAL(low_choose_750fx_pll)
111 /* Clear MSR:EE */
112 mfmsr r7
113 rlwinm r0,r7,0,17,15
114 mtmsr r0
115
116 /* If switching to PLL1, disable HID0:BTIC */
117 cmplwi cr0,r3,0
118 beq 1f
119 mfspr r5,SPRN_HID0
120 rlwinm r5,r5,0,27,25
121 sync
122 mtspr SPRN_HID0,r5
123 isync
124 sync
125
1261:
127 /* Calc new HID1 value */
128 mfspr r4,SPRN_HID1 /* Build a HID1:PS bit from parameter */
129 rlwinm r5,r3,16,15,15 /* Clear out HID1:PS from value read */
130 rlwinm r4,r4,0,16,14 /* Could have I used rlwimi here ? */
131 or r4,r4,r5
132 mtspr SPRN_HID1,r4
133
134#ifdef CONFIG_SMP
135 /* Store new HID1 image */
136 lwz r6,TASK_CPU(r2)
137 slwi r6,r6,2
138#else
139 li r6, 0
140#endif
141 addis r6,r6,nap_save_hid1@ha
142 stw r4,nap_save_hid1@l(r6)
143
144 /* If switching to PLL0, enable HID0:BTIC */
145 cmplwi cr0,r3,0
146 bne 1f
147 mfspr r5,SPRN_HID0
148 ori r5,r5,HID0_BTIC
149 sync
150 mtspr SPRN_HID0,r5
151 isync
152 sync
153
1541:
155 /* Return */
156 mtmsr r7
157 blr
158
159_GLOBAL(low_choose_7447a_dfs)
160 /* Clear MSR:EE */
161 mfmsr r7
162 rlwinm r0,r7,0,17,15
163 mtmsr r0
164
165 /* Calc new HID1 value */
166 mfspr r4,SPRN_HID1
167 insrwi r4,r3,1,9 /* insert parameter into bit 9 */
168 sync
169 mtspr SPRN_HID1,r4
170 sync
171 isync
172
173 /* Return */
174 mtmsr r7
175 blr
176
177#endif /* CONFIG_CPU_FREQ_PMAC && CONFIG_PPC_BOOK3S_32 */
178
179#ifdef CONFIG_40x
180
181/*
182 * Do an IO access in real mode
183 */
184_GLOBAL(real_readb)
185 mfmsr r7
186 rlwinm r0,r7,0,~MSR_DR
187 sync
188 mtmsr r0
189 sync
190 isync
191 lbz r3,0(r3)
192 sync
193 mtmsr r7
194 sync
195 isync
196 blr
197_ASM_NOKPROBE_SYMBOL(real_readb)
198
199 /*
200 * Do an IO access in real mode
201 */
202_GLOBAL(real_writeb)
203 mfmsr r7
204 rlwinm r0,r7,0,~MSR_DR
205 sync
206 mtmsr r0
207 sync
208 isync
209 stb r3,0(r4)
210 sync
211 mtmsr r7
212 sync
213 isync
214 blr
215_ASM_NOKPROBE_SYMBOL(real_writeb)
216
217#endif /* CONFIG_40x */
218
219/*
220 * Copy a whole page. We use the dcbz instruction on the destination
221 * to reduce memory traffic (it eliminates the unnecessary reads of
222 * the destination into cache). This requires that the destination
223 * is cacheable.
224 */
225#define COPY_16_BYTES \
226 lwz r6,4(r4); \
227 lwz r7,8(r4); \
228 lwz r8,12(r4); \
229 lwzu r9,16(r4); \
230 stw r6,4(r3); \
231 stw r7,8(r3); \
232 stw r8,12(r3); \
233 stwu r9,16(r3)
234
235_GLOBAL(copy_page)
236 rlwinm r5, r3, 0, L1_CACHE_BYTES - 1
237 addi r3,r3,-4
238
2390: twnei r5, 0 /* WARN if r3 is not cache aligned */
240 EMIT_WARN_ENTRY 0b,__FILE__,__LINE__, BUGFLAG_WARNING
241
242 addi r4,r4,-4
243
244 li r5,4
245
246#if MAX_COPY_PREFETCH > 1
247 li r0,MAX_COPY_PREFETCH
248 li r11,4
249 mtctr r0
25011: dcbt r11,r4
251 addi r11,r11,L1_CACHE_BYTES
252 bdnz 11b
253#else /* MAX_COPY_PREFETCH == 1 */
254 dcbt r5,r4
255 li r11,L1_CACHE_BYTES+4
256#endif /* MAX_COPY_PREFETCH */
257 li r0,PAGE_SIZE/L1_CACHE_BYTES - MAX_COPY_PREFETCH
258 crclr 4*cr0+eq
2592:
260 mtctr r0
2611:
262 dcbt r11,r4
263 dcbz r5,r3
264 COPY_16_BYTES
265#if L1_CACHE_BYTES >= 32
266 COPY_16_BYTES
267#if L1_CACHE_BYTES >= 64
268 COPY_16_BYTES
269 COPY_16_BYTES
270#if L1_CACHE_BYTES >= 128
271 COPY_16_BYTES
272 COPY_16_BYTES
273 COPY_16_BYTES
274 COPY_16_BYTES
275#endif
276#endif
277#endif
278 bdnz 1b
279 beqlr
280 crnot 4*cr0+eq,4*cr0+eq
281 li r0,MAX_COPY_PREFETCH
282 li r11,4
283 b 2b
284EXPORT_SYMBOL(copy_page)
285
286/*
287 * Extended precision shifts.
288 *
289 * Updated to be valid for shift counts from 0 to 63 inclusive.
290 * -- Gabriel
291 *
292 * R3/R4 has 64 bit value
293 * R5 has shift count
294 * result in R3/R4
295 *
296 * ashrdi3: arithmetic right shift (sign propagation)
297 * lshrdi3: logical right shift
298 * ashldi3: left shift
299 */
300_GLOBAL(__ashrdi3)
301 subfic r6,r5,32
302 srw r4,r4,r5 # LSW = count > 31 ? 0 : LSW >> count
303 addi r7,r5,32 # could be xori, or addi with -32
304 slw r6,r3,r6 # t1 = count > 31 ? 0 : MSW << (32-count)
305 rlwinm r8,r7,0,32 # t3 = (count < 32) ? 32 : 0
306 sraw r7,r3,r7 # t2 = MSW >> (count-32)
307 or r4,r4,r6 # LSW |= t1
308 slw r7,r7,r8 # t2 = (count < 32) ? 0 : t2
309 sraw r3,r3,r5 # MSW = MSW >> count
310 or r4,r4,r7 # LSW |= t2
311 blr
312EXPORT_SYMBOL(__ashrdi3)
313
314_GLOBAL(__ashldi3)
315 subfic r6,r5,32
316 slw r3,r3,r5 # MSW = count > 31 ? 0 : MSW << count
317 addi r7,r5,32 # could be xori, or addi with -32
318 srw r6,r4,r6 # t1 = count > 31 ? 0 : LSW >> (32-count)
319 slw r7,r4,r7 # t2 = count < 32 ? 0 : LSW << (count-32)
320 or r3,r3,r6 # MSW |= t1
321 slw r4,r4,r5 # LSW = LSW << count
322 or r3,r3,r7 # MSW |= t2
323 blr
324EXPORT_SYMBOL(__ashldi3)
325
326_GLOBAL(__lshrdi3)
327 subfic r6,r5,32
328 srw r4,r4,r5 # LSW = count > 31 ? 0 : LSW >> count
329 addi r7,r5,32 # could be xori, or addi with -32
330 slw r6,r3,r6 # t1 = count > 31 ? 0 : MSW << (32-count)
331 srw r7,r3,r7 # t2 = count < 32 ? 0 : MSW >> (count-32)
332 or r4,r4,r6 # LSW |= t1
333 srw r3,r3,r5 # MSW = MSW >> count
334 or r4,r4,r7 # LSW |= t2
335 blr
336EXPORT_SYMBOL(__lshrdi3)
337
338/*
339 * 64-bit comparison: __cmpdi2(s64 a, s64 b)
340 * Returns 0 if a < b, 1 if a == b, 2 if a > b.
341 */
342_GLOBAL(__cmpdi2)
343 cmpw r3,r5
344 li r3,1
345 bne 1f
346 cmplw r4,r6
347 beqlr
3481: li r3,0
349 bltlr
350 li r3,2
351 blr
352EXPORT_SYMBOL(__cmpdi2)
353/*
354 * 64-bit comparison: __ucmpdi2(u64 a, u64 b)
355 * Returns 0 if a < b, 1 if a == b, 2 if a > b.
356 */
357_GLOBAL(__ucmpdi2)
358 cmplw r3,r5
359 li r3,1
360 bne 1f
361 cmplw r4,r6
362 beqlr
3631: li r3,0
364 bltlr
365 li r3,2
366 blr
367EXPORT_SYMBOL(__ucmpdi2)
368
369_GLOBAL(__bswapdi2)
370 rotlwi r9,r4,8
371 rotlwi r10,r3,8
372 rlwimi r9,r4,24,0,7
373 rlwimi r10,r3,24,0,7
374 rlwimi r9,r4,24,16,23
375 rlwimi r10,r3,24,16,23
376 mr r3,r9
377 mr r4,r10
378 blr
379EXPORT_SYMBOL(__bswapdi2)
380
381#ifdef CONFIG_SMP
382_GLOBAL(start_secondary_resume)
383 /* Reset stack */
384 rlwinm r1, r1, 0, 0, 31 - THREAD_SHIFT
385 addi r1,r1,THREAD_SIZE-STACK_FRAME_MIN_SIZE
386 li r3,0
387 stw r3,0(r1) /* Zero the stack frame pointer */
388 bl start_secondary
389 b .
390#endif /* CONFIG_SMP */
391

source code of linux/arch/powerpc/kernel/misc_32.S