1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (C) 1994 Waldorf GMBH
7  * Copyright (C) 1995, 1996, 1997, 1998, 1999, 2001, 2002, 2003 Ralf Baechle
8  * Copyright (C) 1996 Paul M. Antoine
9  * Copyright (C) 1999, 2000 Silicon Graphics, Inc.
10  */
11 #ifndef _ASM_PROCESSOR_H
12 #define _ASM_PROCESSOR_H
13 
14 #include <linux/cpumask.h>
15 #include <linux/threads.h>
16 
17 #include <asm/cachectl.h>
18 #include <asm/cpu.h>
19 #include <asm/cpu-info.h>
20 #include <asm/mipsregs.h>
21 #include <asm/prefetch.h>
22 #include <asm/system.h>
23 
24 /*
25  * Return current * instruction pointer ("program counter").
26  */
27 #define current_text_addr() ({ __label__ _l; _l: &&_l;})
28 
29 /*
30  * System setup and hardware flags..
31  */
32 extern void (*cpu_wait)(void);
33 
34 extern unsigned int vced_count, vcei_count;
35 
36 /*
37  * MIPS does have an arch_pick_mmap_layout()
38  */
39 #define HAVE_ARCH_PICK_MMAP_LAYOUT 1
40 
41 /*
42  * A special page (the vdso) is mapped into all processes at the very
43  * top of the virtual memory space.
44  */
45 #define SPECIAL_PAGES_SIZE PAGE_SIZE
46 
47 #ifdef CONFIG_32BIT
48 /*
49  * User space process size: 2GB. This is hardcoded into a few places,
50  * so don't change it unless you know what you are doing.
51  */
52 #define TASK_SIZE	0x7fff8000UL
53 
54 #ifdef __KERNEL__
55 #define STACK_TOP_MAX	TASK_SIZE
56 #endif
57 
58 #define TASK_IS_32BIT_ADDR 1
59 
60 #endif
61 
62 #ifdef CONFIG_64BIT
63 /*
64  * User space process size: 1TB. This is hardcoded into a few places,
65  * so don't change it unless you know what you are doing.  TASK_SIZE
66  * is limited to 1TB by the R4000 architecture; R10000 and better can
67  * support 16TB; the architectural reserve for future expansion is
68  * 8192EB ...
69  */
70 #define TASK_SIZE32	0x7fff8000UL
71 #define TASK_SIZE64	0x10000000000UL
72 #define TASK_SIZE (test_thread_flag(TIF_32BIT_ADDR) ? TASK_SIZE32 : TASK_SIZE64)
73 
74 #ifdef __KERNEL__
75 #define STACK_TOP_MAX	TASK_SIZE64
76 #endif
77 
78 
79 #define TASK_SIZE_OF(tsk)						\
80 	(test_tsk_thread_flag(tsk, TIF_32BIT_ADDR) ? TASK_SIZE32 : TASK_SIZE64)
81 
82 #define TASK_IS_32BIT_ADDR test_thread_flag(TIF_32BIT_ADDR)
83 
84 #endif
85 
86 #define STACK_TOP	((TASK_SIZE & PAGE_MASK) - SPECIAL_PAGES_SIZE)
87 
88 /*
89  * This decides where the kernel will search for a free chunk of vm
90  * space during mmap's.
91  */
92 #define TASK_UNMAPPED_BASE PAGE_ALIGN(TASK_SIZE / 3)
93 
94 
95 #define NUM_FPU_REGS	32
96 
97 typedef __u64 fpureg_t;
98 
99 /*
100  * It would be nice to add some more fields for emulator statistics, but there
101  * are a number of fixed offsets in offset.h and elsewhere that would have to
102  * be recalculated by hand.  So the additional information will be private to
103  * the FPU emulator for now.  See asm-mips/fpu_emulator.h.
104  */
105 
106 struct mips_fpu_struct {
107 	fpureg_t	fpr[NUM_FPU_REGS];
108 	unsigned int	fcr31;
109 };
110 
111 #define NUM_DSP_REGS   6
112 
113 typedef __u32 dspreg_t;
114 
115 struct mips_dsp_state {
116 	dspreg_t        dspr[NUM_DSP_REGS];
117 	unsigned int    dspcontrol;
118 };
119 
120 #define INIT_CPUMASK { \
121 	{0,} \
122 }
123 
124 struct mips3264_watch_reg_state {
125 	/* The width of watchlo is 32 in a 32 bit kernel and 64 in a
126 	   64 bit kernel.  We use unsigned long as it has the same
127 	   property. */
128 	unsigned long watchlo[NUM_WATCH_REGS];
129 	/* Only the mask and IRW bits from watchhi. */
130 	u16 watchhi[NUM_WATCH_REGS];
131 };
132 
133 union mips_watch_reg_state {
134 	struct mips3264_watch_reg_state mips3264;
135 };
136 
137 #ifdef CONFIG_CPU_CAVIUM_OCTEON
138 
139 struct octeon_cop2_state {
140 	/* DMFC2 rt, 0x0201 */
141 	unsigned long   cop2_crc_iv;
142 	/* DMFC2 rt, 0x0202 (Set with DMTC2 rt, 0x1202) */
143 	unsigned long   cop2_crc_length;
144 	/* DMFC2 rt, 0x0200 (set with DMTC2 rt, 0x4200) */
145 	unsigned long   cop2_crc_poly;
146 	/* DMFC2 rt, 0x0402; DMFC2 rt, 0x040A */
147 	unsigned long   cop2_llm_dat[2];
148        /* DMFC2 rt, 0x0084 */
149 	unsigned long   cop2_3des_iv;
150 	/* DMFC2 rt, 0x0080; DMFC2 rt, 0x0081; DMFC2 rt, 0x0082 */
151 	unsigned long   cop2_3des_key[3];
152 	/* DMFC2 rt, 0x0088 (Set with DMTC2 rt, 0x0098) */
153 	unsigned long   cop2_3des_result;
154 	/* DMFC2 rt, 0x0111 (FIXME: Read Pass1 Errata) */
155 	unsigned long   cop2_aes_inp0;
156 	/* DMFC2 rt, 0x0102; DMFC2 rt, 0x0103 */
157 	unsigned long   cop2_aes_iv[2];
158 	/* DMFC2 rt, 0x0104; DMFC2 rt, 0x0105; DMFC2 rt, 0x0106; DMFC2
159 	 * rt, 0x0107 */
160 	unsigned long   cop2_aes_key[4];
161 	/* DMFC2 rt, 0x0110 */
162 	unsigned long   cop2_aes_keylen;
163 	/* DMFC2 rt, 0x0100; DMFC2 rt, 0x0101 */
164 	unsigned long   cop2_aes_result[2];
165 	/* DMFC2 rt, 0x0240; DMFC2 rt, 0x0241; DMFC2 rt, 0x0242; DMFC2
166 	 * rt, 0x0243; DMFC2 rt, 0x0244; DMFC2 rt, 0x0245; DMFC2 rt,
167 	 * 0x0246; DMFC2 rt, 0x0247; DMFC2 rt, 0x0248; DMFC2 rt,
168 	 * 0x0249; DMFC2 rt, 0x024A; DMFC2 rt, 0x024B; DMFC2 rt,
169 	 * 0x024C; DMFC2 rt, 0x024D; DMFC2 rt, 0x024E - Pass2 */
170 	unsigned long   cop2_hsh_datw[15];
171 	/* DMFC2 rt, 0x0250; DMFC2 rt, 0x0251; DMFC2 rt, 0x0252; DMFC2
172 	 * rt, 0x0253; DMFC2 rt, 0x0254; DMFC2 rt, 0x0255; DMFC2 rt,
173 	 * 0x0256; DMFC2 rt, 0x0257 - Pass2 */
174 	unsigned long   cop2_hsh_ivw[8];
175 	/* DMFC2 rt, 0x0258; DMFC2 rt, 0x0259 - Pass2 */
176 	unsigned long   cop2_gfm_mult[2];
177 	/* DMFC2 rt, 0x025E - Pass2 */
178 	unsigned long   cop2_gfm_poly;
179 	/* DMFC2 rt, 0x025A; DMFC2 rt, 0x025B - Pass2 */
180 	unsigned long   cop2_gfm_result[2];
181 };
182 #define INIT_OCTEON_COP2 {0,}
183 
184 struct octeon_cvmseg_state {
185 	unsigned long cvmseg[CONFIG_CAVIUM_OCTEON_CVMSEG_SIZE]
186 			    [cpu_dcache_line_size() / sizeof(unsigned long)];
187 };
188 
189 #endif
190 
191 typedef struct {
192 	unsigned long seg;
193 } mm_segment_t;
194 
195 #define ARCH_MIN_TASKALIGN	8
196 
197 struct mips_abi;
198 
199 /*
200  * If you change thread_struct remember to change the #defines below too!
201  */
202 struct thread_struct {
203 	/* Saved main processor registers. */
204 	unsigned long reg16;
205 	unsigned long reg17, reg18, reg19, reg20, reg21, reg22, reg23;
206 	unsigned long reg29, reg30, reg31;
207 
208 	/* Saved cp0 stuff. */
209 	unsigned long cp0_status;
210 
211 	/* Saved fpu/fpu emulator stuff. */
212 	struct mips_fpu_struct fpu;
213 #ifdef CONFIG_MIPS_MT_FPAFF
214 	/* Emulated instruction count */
215 	unsigned long emulated_fp;
216 	/* Saved per-thread scheduler affinity mask */
217 	cpumask_t user_cpus_allowed;
218 #endif /* CONFIG_MIPS_MT_FPAFF */
219 
220 	/* Saved state of the DSP ASE, if available. */
221 	struct mips_dsp_state dsp;
222 
223 	/* Saved watch register state, if available. */
224 	union mips_watch_reg_state watch;
225 
226 	/* Other stuff associated with the thread. */
227 	unsigned long cp0_badvaddr;	/* Last user fault */
228 	unsigned long cp0_baduaddr;	/* Last kernel fault accessing USEG */
229 	unsigned long error_code;
230 	unsigned long irix_trampoline;  /* Wheee... */
231 	unsigned long irix_oldctx;
232 #ifdef CONFIG_CPU_CAVIUM_OCTEON
233     struct octeon_cop2_state cp2 __attribute__ ((__aligned__(128)));
234     struct octeon_cvmseg_state cvmseg __attribute__ ((__aligned__(128)));
235 #endif
236 	struct mips_abi *abi;
237 };
238 
239 #ifdef CONFIG_MIPS_MT_FPAFF
240 #define FPAFF_INIT						\
241 	.emulated_fp			= 0,			\
242 	.user_cpus_allowed		= INIT_CPUMASK,
243 #else
244 #define FPAFF_INIT
245 #endif /* CONFIG_MIPS_MT_FPAFF */
246 
247 #ifdef CONFIG_CPU_CAVIUM_OCTEON
248 #define OCTEON_INIT						\
249 	.cp2			= INIT_OCTEON_COP2,
250 #else
251 #define OCTEON_INIT
252 #endif /* CONFIG_CPU_CAVIUM_OCTEON */
253 
254 #define INIT_THREAD  {						\
255         /*							\
256          * Saved main processor registers			\
257          */							\
258 	.reg16			= 0,				\
259 	.reg17			= 0,				\
260 	.reg18			= 0,				\
261 	.reg19			= 0,				\
262 	.reg20			= 0,				\
263 	.reg21			= 0,				\
264 	.reg22			= 0,				\
265 	.reg23			= 0,				\
266 	.reg29			= 0,				\
267 	.reg30			= 0,				\
268 	.reg31			= 0,				\
269 	/*							\
270 	 * Saved cp0 stuff					\
271 	 */							\
272 	.cp0_status		= 0,				\
273 	/*							\
274 	 * Saved FPU/FPU emulator stuff				\
275 	 */							\
276 	.fpu			= {				\
277 		.fpr		= {0,},				\
278 		.fcr31		= 0,				\
279 	},							\
280 	/*							\
281 	 * FPU affinity state (null if not FPAFF)		\
282 	 */							\
283 	FPAFF_INIT						\
284 	/*							\
285 	 * Saved DSP stuff					\
286 	 */							\
287 	.dsp			= {				\
288 		.dspr		= {0, },			\
289 		.dspcontrol	= 0,				\
290 	},							\
291 	/*							\
292 	 * saved watch register stuff				\
293 	 */							\
294 	.watch = {{{0,},},},					\
295 	/*							\
296 	 * Other stuff associated with the process		\
297 	 */							\
298 	.cp0_badvaddr		= 0,				\
299 	.cp0_baduaddr		= 0,				\
300 	.error_code		= 0,				\
301 	.irix_trampoline	= 0,				\
302 	.irix_oldctx		= 0,				\
303 	/*							\
304 	 * Cavium Octeon specifics (null if not Octeon)		\
305 	 */							\
306 	OCTEON_INIT						\
307 }
308 
309 struct task_struct;
310 
311 /* Free all resources held by a thread. */
312 #define release_thread(thread) do { } while(0)
313 
314 /* Prepare to copy thread state - unlazy all lazy status */
315 #define prepare_to_copy(tsk)	do { } while (0)
316 
317 extern long kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
318 
319 extern unsigned long thread_saved_pc(struct task_struct *tsk);
320 
321 /*
322  * Do necessary setup to start up a newly executed thread.
323  */
324 extern void start_thread(struct pt_regs * regs, unsigned long pc, unsigned long sp);
325 
326 unsigned long get_wchan(struct task_struct *p);
327 
328 #define __KSTK_TOS(tsk) ((unsigned long)task_stack_page(tsk) + \
329 			 THREAD_SIZE - 32 - sizeof(struct pt_regs))
330 #define task_pt_regs(tsk) ((struct pt_regs *)__KSTK_TOS(tsk))
331 #define KSTK_EIP(tsk) (task_pt_regs(tsk)->cp0_epc)
332 #define KSTK_ESP(tsk) (task_pt_regs(tsk)->regs[29])
333 #define KSTK_STATUS(tsk) (task_pt_regs(tsk)->cp0_status)
334 
335 #define cpu_relax()	barrier()
336 
337 /*
338  * Return_address is a replacement for __builtin_return_address(count)
339  * which on certain architectures cannot reasonably be implemented in GCC
340  * (MIPS, Alpha) or is unusable with -fomit-frame-pointer (i386).
341  * Note that __builtin_return_address(x>=1) is forbidden because GCC
342  * aborts compilation on some CPUs.  It's simply not possible to unwind
343  * some CPU's stackframes.
344  *
345  * __builtin_return_address works only for non-leaf functions.  We avoid the
346  * overhead of a function call by forcing the compiler to save the return
347  * address register on the stack.
348  */
349 #define return_address() ({__asm__ __volatile__("":::"$31");__builtin_return_address(0);})
350 
351 #ifdef CONFIG_CPU_HAS_PREFETCH
352 
353 #define ARCH_HAS_PREFETCH
354 #define prefetch(x) __builtin_prefetch((x), 0, 1)
355 
356 #define ARCH_HAS_PREFETCHW
357 #define prefetchw(x) __builtin_prefetch((x), 1, 1)
358 
359 #endif
360 
361 #endif /* _ASM_PROCESSOR_H */
362