Merge branch 'linus' into stackprotector
[linux-2.6] / arch / sparc / mm / btfixup.c
1 /* btfixup.c: Boot time code fixup and relocator, so that
2  * we can get rid of most indirect calls to achieve single
3  * image sun4c and srmmu kernel.
4  *
5  * Copyright (C) 1998 Jakub Jelinek (jj@sunsite.mff.cuni.cz)
6  */
7
8 #include <linux/kernel.h>
9 #include <linux/init.h>
10 #include <asm/btfixup.h>
11 #include <asm/page.h>
12 #include <asm/pgalloc.h>
13 #include <asm/pgtable.h>
14 #include <asm/oplib.h>
15 #include <asm/system.h>
16 #include <asm/cacheflush.h>
17
18 #define BTFIXUP_OPTIMIZE_NOP
19 #define BTFIXUP_OPTIMIZE_OTHER
20
21 extern char *srmmu_name;
22 static char version[] __initdata = "Boot time fixup v1.6. 4/Mar/98 Jakub Jelinek (jj@ultra.linux.cz). Patching kernel for ";
23 static char str_sun4c[] __initdata = "sun4c\n";
24 static char str_srmmu[] __initdata = "srmmu[%s]/";
25 static char str_iommu[] __initdata = "iommu\n";
26 static char str_iounit[] __initdata = "io-unit\n";
27
28 static int visited __initdata = 0;
29 extern unsigned int ___btfixup_start[], ___btfixup_end[], __init_begin[], __init_end[], __init_text_end[];
30 extern unsigned int _stext[], _end[], __start___ksymtab[], __stop___ksymtab[];
31 static char wrong_f[] __initdata = "Trying to set f fixup %p to invalid function %08x\n";
32 static char wrong_b[] __initdata = "Trying to set b fixup %p to invalid function %08x\n";
33 static char wrong_s[] __initdata = "Trying to set s fixup %p to invalid value %08x\n";
34 static char wrong_h[] __initdata = "Trying to set h fixup %p to invalid value %08x\n";
35 static char wrong_a[] __initdata = "Trying to set a fixup %p to invalid value %08x\n";
36 static char wrong[] __initdata = "Wrong address for %c fixup %p\n";
37 static char insn_f[] __initdata = "Fixup f %p refers to weird instructions at %p[%08x,%08x]\n";
38 static char insn_b[] __initdata = "Fixup b %p doesn't refer to a SETHI at %p[%08x]\n";
39 static char insn_s[] __initdata = "Fixup s %p doesn't refer to an OR at %p[%08x]\n";
40 static char insn_h[] __initdata = "Fixup h %p doesn't refer to a SETHI at %p[%08x]\n";
41 static char insn_a[] __initdata = "Fixup a %p doesn't refer to a SETHI nor OR at %p[%08x]\n";
42 static char insn_i[] __initdata = "Fixup i %p doesn't refer to a valid instruction at %p[%08x]\n";
43 static char fca_und[] __initdata = "flush_cache_all undefined in btfixup()\n";
44 static char wrong_setaddr[] __initdata = "Garbled CALL/INT patch at %p[%08x,%08x,%08x]=%08x\n";
45
46 #ifdef BTFIXUP_OPTIMIZE_OTHER
47 static void __init set_addr(unsigned int *addr, unsigned int q1, int fmangled, unsigned int value)
48 {
49         if (!fmangled)
50                 *addr = value;
51         else {
52                 unsigned int *q = (unsigned int *)q1;
53                 if (*addr == 0x01000000) {
54                         /* Noped */
55                         *q = value;
56                 } else if (addr[-1] == *q) {
57                         /* Moved */
58                         addr[-1] = value;
59                         *q = value;
60                 } else {
61                         prom_printf(wrong_setaddr, addr-1, addr[-1], *addr, *q, value);
62                         prom_halt();
63                 }
64         }
65 }
66 #else
67 static inline void set_addr(unsigned int *addr, unsigned int q1, int fmangled, unsigned int value)
68 {
69         *addr = value;
70 }
71 #endif
72
73 void __init btfixup(void)
74 {
75         unsigned int *p, *q;
76         int type, count;
77         unsigned insn;
78         unsigned *addr;
79         int fmangled = 0;
80         void (*flush_cacheall)(void);
81         
82         if (!visited) {
83                 visited++;
84                 printk(version);
85                 if (ARCH_SUN4C)
86                         printk(str_sun4c);
87                 else {
88                         printk(str_srmmu, srmmu_name);
89                         if (sparc_cpu_model == sun4d)
90                                 printk(str_iounit);
91                         else
92                                 printk(str_iommu);
93                 }
94         }
95         for (p = ___btfixup_start; p < ___btfixup_end; ) {
96                 count = p[2];
97                 q = p + 3;
98                 switch (type = *(unsigned char *)p) {
99                 case 'f': 
100                         count = p[3];
101                         q = p + 4;
102                         if (((p[0] & 1) || p[1]) 
103                             && ((p[1] & 3) || (unsigned *)(p[1]) < _stext || (unsigned *)(p[1]) >= _end)) {
104                                 prom_printf(wrong_f, p, p[1]);
105                                 prom_halt();
106                         }
107                         break;
108                 case 'b':
109                         if (p[1] < (unsigned long)__init_begin || p[1] >= (unsigned long)__init_text_end || (p[1] & 3)) {
110                                 prom_printf(wrong_b, p, p[1]);
111                                 prom_halt();
112                         }
113                         break;
114                 case 's':
115                         if (p[1] + 0x1000 >= 0x2000) {
116                                 prom_printf(wrong_s, p, p[1]);
117                                 prom_halt();
118                         }
119                         break;
120                 case 'h':
121                         if (p[1] & 0x3ff) {
122                                 prom_printf(wrong_h, p, p[1]);
123                                 prom_halt();
124                         }
125                         break;
126                 case 'a':
127                         if (p[1] + 0x1000 >= 0x2000 && (p[1] & 0x3ff)) {
128                                 prom_printf(wrong_a, p, p[1]);
129                                 prom_halt();
130                         }
131                         break;
132                 }
133                 if (p[0] & 1) {
134                         p[0] &= ~1;
135                         while (count) {
136                                 fmangled = 0;
137                                 addr = (unsigned *)*q;
138                                 if (addr < _stext || addr >= _end) {
139                                         prom_printf(wrong, type, p);
140                                         prom_halt();
141                                 }
142                                 insn = *addr;
143 #ifdef BTFIXUP_OPTIMIZE_OTHER                           
144                                 if (type != 'f' && q[1]) {
145                                         insn = *(unsigned int *)q[1];
146                                         if (!insn || insn == 1)
147                                                 insn = *addr;
148                                         else
149                                                 fmangled = 1;
150                                 }
151 #endif
152                                 switch (type) {
153                                 case 'f':       /* CALL */
154                                         if (addr >= __start___ksymtab && addr < __stop___ksymtab) {
155                                                 *addr = p[1];
156                                                 break;
157                                         } else if (!q[1]) {
158                                                 if ((insn & 0xc1c00000) == 0x01000000) { /* SETHI */
159                                                         *addr = (insn & 0xffc00000) | (p[1] >> 10); break;
160                                                 } else if ((insn & 0xc1f82000) == 0x80102000) { /* OR X, %LO(i), Y */
161                                                         *addr = (insn & 0xffffe000) | (p[1] & 0x3ff); break;
162                                                 } else if ((insn & 0xc0000000) != 0x40000000) { /* !CALL */
163                                 bad_f:
164                                                         prom_printf(insn_f, p, addr, insn, addr[1]);
165                                                         prom_halt();
166                                                 }
167                                         } else if (q[1] != 1)
168                                                 addr[1] = q[1];
169                                         if (p[2] == BTFIXUPCALL_NORM) {
170                                 norm_f: 
171                                                 *addr = 0x40000000 | ((p[1] - (unsigned)addr) >> 2);
172                                                 q[1] = 0;
173                                                 break;
174                                         }
175 #ifndef BTFIXUP_OPTIMIZE_NOP
176                                         goto norm_f;
177 #else
178                                         if (!(addr[1] & 0x80000000)) {
179                                                 if ((addr[1] & 0xc1c00000) != 0x01000000)       /* !SETHI */
180                                                         goto bad_f; /* CALL, Bicc, FBfcc, CBccc are weird in delay slot, aren't they? */
181                                         } else {
182                                                 if ((addr[1] & 0x01800000) == 0x01800000) {
183                                                         if ((addr[1] & 0x01f80000) == 0x01e80000) {
184                                                                 /* RESTORE */
185                                                                 goto norm_f; /* It is dangerous to patch that */
186                                                         }
187                                                         goto bad_f;
188                                                 }
189                                                 if ((addr[1] & 0xffffe003) == 0x9e03e000) {
190                                                         /* ADD %O7, XX, %o7 */
191                                                         int displac = (addr[1] << 19);
192                                                         
193                                                         displac = (displac >> 21) + 2;
194                                                         *addr = (0x10800000) + (displac & 0x3fffff);
195                                                         q[1] = addr[1];
196                                                         addr[1] = p[2];
197                                                         break;
198                                                 }
199                                                 if ((addr[1] & 0x201f) == 0x200f || (addr[1] & 0x7c000) == 0x3c000)
200                                                         goto norm_f; /* Someone is playing bad tricks with us: rs1 or rs2 is o7 */
201                                                 if ((addr[1] & 0x3e000000) == 0x1e000000)
202                                                         goto norm_f; /* rd is %o7. We'd better take care. */
203                                         }
204                                         if (p[2] == BTFIXUPCALL_NOP) {
205                                                 *addr = 0x01000000;
206                                                 q[1] = 1;
207                                                 break;
208                                         }
209 #ifndef BTFIXUP_OPTIMIZE_OTHER
210                                         goto norm_f;
211 #else
212                                         if (addr[1] == 0x01000000) {    /* NOP in the delay slot */
213                                                 q[1] = addr[1];
214                                                 *addr = p[2];
215                                                 break;
216                                         }
217                                         if ((addr[1] & 0xc0000000) != 0xc0000000) {
218                                                 /* Not a memory operation */
219                                                 if ((addr[1] & 0x30000000) == 0x10000000) {
220                                                         /* Ok, non-memory op with rd %oX */
221                                                         if ((addr[1] & 0x3e000000) == 0x1c000000)
222                                                                 goto bad_f; /* Aiee. Someone is playing strange %sp tricks */
223                                                         if ((addr[1] & 0x3e000000) > 0x12000000 ||
224                                                             ((addr[1] & 0x3e000000) == 0x12000000 &&
225                                                              p[2] != BTFIXUPCALL_STO1O0 && p[2] != BTFIXUPCALL_SWAPO0O1) ||
226                                                             ((p[2] & 0xffffe000) == BTFIXUPCALL_RETINT(0))) {
227                                                                 /* Nobody uses the result. We can nop it out. */
228                                                                 *addr = p[2];
229                                                                 q[1] = addr[1];
230                                                                 addr[1] = 0x01000000;
231                                                                 break;
232                                                         }
233                                                         if ((addr[1] & 0xf1ffffe0) == 0x90100000) {
234                                                                 /* MOV %reg, %Ox */
235                                                                 if ((addr[1] & 0x3e000000) == 0x10000000 &&
236                                                                     (p[2] & 0x7c000) == 0x20000) {
237                                                                         /* Ok, it is call xx; mov reg, %o0 and call optimizes
238                                                                            to doing something on %o0. Patch the patch. */
239                                                                         *addr = (p[2] & ~0x7c000) | ((addr[1] & 0x1f) << 14);
240                                                                         q[1] = addr[1];
241                                                                         addr[1] = 0x01000000;
242                                                                         break;
243                                                                 }
244                                                                 if ((addr[1] & 0x3e000000) == 0x12000000 &&
245                                                                     p[2] == BTFIXUPCALL_STO1O0) {
246                                                                         *addr = (p[2] & ~0x3e000000) | ((addr[1] & 0x1f) << 25);
247                                                                         q[1] = addr[1];
248                                                                         addr[1] = 0x01000000;
249                                                                         break;
250                                                                 }
251                                                         }
252                                                 }
253                                         }
254                                         *addr = addr[1];
255                                         q[1] = addr[1];
256                                         addr[1] = p[2];
257                                         break;
258 #endif /* BTFIXUP_OPTIMIZE_OTHER */
259 #endif /* BTFIXUP_OPTIMIZE_NOP */
260                                 case 'b':       /* BLACKBOX */
261                                         /* Has to be sethi i, xx */
262                                         if ((insn & 0xc1c00000) != 0x01000000) {
263                                                 prom_printf(insn_b, p, addr, insn);
264                                                 prom_halt();
265                                         } else {
266                                                 void (*do_fixup)(unsigned *);
267                                                 
268                                                 do_fixup = (void (*)(unsigned *))p[1];
269                                                 do_fixup(addr);
270                                         }
271                                         break;
272                                 case 's':       /* SIMM13 */
273                                         /* Has to be or %g0, i, xx */
274                                         if ((insn & 0xc1ffe000) != 0x80102000) {
275                                                 prom_printf(insn_s, p, addr, insn);
276                                                 prom_halt();
277                                         }
278                                         set_addr(addr, q[1], fmangled, (insn & 0xffffe000) | (p[1] & 0x1fff));
279                                         break;
280                                 case 'h':       /* SETHI */
281                                         /* Has to be sethi i, xx */
282                                         if ((insn & 0xc1c00000) != 0x01000000) {
283                                                 prom_printf(insn_h, p, addr, insn);
284                                                 prom_halt();
285                                         }
286                                         set_addr(addr, q[1], fmangled, (insn & 0xffc00000) | (p[1] >> 10));
287                                         break;
288                                 case 'a':       /* HALF */
289                                         /* Has to be sethi i, xx or or %g0, i, xx */
290                                         if ((insn & 0xc1c00000) != 0x01000000 &&
291                                             (insn & 0xc1ffe000) != 0x80102000) {
292                                                 prom_printf(insn_a, p, addr, insn);
293                                                 prom_halt();
294                                         }
295                                         if (p[1] & 0x3ff)
296                                                 set_addr(addr, q[1], fmangled, 
297                                                         (insn & 0x3e000000) | 0x80102000 | (p[1] & 0x1fff));
298                                         else
299                                                 set_addr(addr, q[1], fmangled, 
300                                                         (insn & 0x3e000000) | 0x01000000 | (p[1] >> 10));
301                                         break;
302                                 case 'i':       /* INT */
303                                         if ((insn & 0xc1c00000) == 0x01000000) /* %HI */
304                                                 set_addr(addr, q[1], fmangled, (insn & 0xffc00000) | (p[1] >> 10));
305                                         else if ((insn & 0x80002000) == 0x80002000 &&
306                                                  (insn & 0x01800000) != 0x01800000) /* %LO */
307                                                 set_addr(addr, q[1], fmangled, (insn & 0xffffe000) | (p[1] & 0x3ff));
308                                         else {
309                                                 prom_printf(insn_i, p, addr, insn);
310                                                 prom_halt();
311                                         }
312                                         break;
313                                 }
314                                 count -= 2;
315                                 q += 2;
316                         }
317                 } else
318                         p = q + count;
319         }
320 #ifdef CONFIG_SMP
321         flush_cacheall = (void (*)(void))BTFIXUPVAL_CALL(local_flush_cache_all);
322 #else
323         flush_cacheall = (void (*)(void))BTFIXUPVAL_CALL(flush_cache_all);
324 #endif
325         if (!flush_cacheall) {
326                 prom_printf(fca_und);
327                 prom_halt();
328         }
329         (*flush_cacheall)();
330 }