1 /*
2  * include/asm-parisc/processor.h
3  *
4  * Copyright (C) 1994 Linus Torvalds
5  * Copyright (C) 2001 Grant Grundler
6  */
7 
8 #ifndef __ASM_PARISC_PROCESSOR_H
9 #define __ASM_PARISC_PROCESSOR_H
10 
11 #ifndef __ASSEMBLY__
12 #include <linux/threads.h>
13 
14 #include <asm/prefetch.h>
15 #include <asm/hardware.h>
16 #include <asm/pdc.h>
17 #include <asm/ptrace.h>
18 #include <asm/types.h>
19 #include <asm/percpu.h>
20 #endif /* __ASSEMBLY__ */
21 
22 /*
23  * Default implementation of macro that returns current
24  * instruction pointer ("program counter").
25  */
26 #ifdef CONFIG_PA20
27 #define current_ia(x)	__asm__("mfia %0" : "=r"(x))
28 #else /* mfia added in pa2.0 */
29 #define current_ia(x)	__asm__("blr 0,%0\n\tnop" : "=r"(x))
30 #endif
31 #define current_text_addr() ({ void *pc; current_ia(pc); pc; })
32 
33 #define HAVE_ARCH_PICK_MMAP_LAYOUT
34 
35 #define TASK_SIZE_OF(tsk)       ((tsk)->thread.task_size)
36 #define TASK_SIZE	        TASK_SIZE_OF(current)
37 #define TASK_UNMAPPED_BASE      (current->thread.map_base)
38 
39 #define DEFAULT_TASK_SIZE32	(0xFFF00000UL)
40 #define DEFAULT_MAP_BASE32	(0x40000000UL)
41 
42 #ifdef CONFIG_64BIT
43 #define DEFAULT_TASK_SIZE       (MAX_ADDRESS-0xf000000)
44 #define DEFAULT_MAP_BASE        (0x200000000UL)
45 #else
46 #define DEFAULT_TASK_SIZE	DEFAULT_TASK_SIZE32
47 #define DEFAULT_MAP_BASE	DEFAULT_MAP_BASE32
48 #endif
49 
50 #ifdef __KERNEL__
51 
52 /* XXX: STACK_TOP actually should be STACK_BOTTOM for parisc.
53  * prumpf */
54 
55 #define STACK_TOP	TASK_SIZE
56 #define STACK_TOP_MAX	DEFAULT_TASK_SIZE
57 
58 /* Allow bigger stacks for 64-bit processes */
59 #define STACK_SIZE_MAX	(USER_WIDE_MODE					\
60 			 ? (1 << 30)	/* 1 GB */			\
61 			 : (CONFIG_MAX_STACK_SIZE_MB*1024*1024))
62 
63 #endif
64 
65 #ifndef __ASSEMBLY__
66 
67 /*
68  * Data detected about CPUs at boot time which is the same for all CPU's.
69  * HP boxes are SMP - ie identical processors.
70  *
71  * FIXME: some CPU rev info may be processor specific...
72  */
73 struct system_cpuinfo_parisc {
74 	unsigned int	cpu_count;
75 	unsigned int	cpu_hz;
76 	unsigned int	hversion;
77 	unsigned int	sversion;
78 	enum cpu_type	cpu_type;
79 
80 	struct {
81 		struct pdc_model model;
82 		unsigned long versions;
83 		unsigned long cpuid;
84 		unsigned long capabilities;
85 		char   sys_model_name[81]; /* PDC-ROM returnes this model name */
86 	} pdc;
87 
88 	const char	*cpu_name;	/* e.g. "PA7300LC (PCX-L2)" */
89 	const char	*family_name;	/* e.g. "1.1e" */
90 };
91 
92 
93 /* Per CPU data structure - ie varies per CPU.  */
94 struct cpuinfo_parisc {
95 	unsigned long it_value;     /* Interval Timer at last timer Intr */
96 	unsigned long irq_count;    /* number of IRQ's since boot */
97 	unsigned long cpuid;        /* aka slot_number or set to NO_PROC_ID */
98 	unsigned long hpa;          /* Host Physical address */
99 	unsigned long txn_addr;     /* MMIO addr of EIR or id_eid */
100 #ifdef CONFIG_SMP
101 	unsigned long pending_ipi;  /* bitmap of type ipi_message_type */
102 #endif
103 	unsigned long bh_count;     /* number of times bh was invoked */
104 	unsigned long fp_rev;
105 	unsigned long fp_model;
106 	unsigned long cpu_num;      /* CPU number from PAT firmware */
107 	unsigned long cpu_loc;      /* CPU location from PAT firmware */
108 	unsigned int state;
109 	struct parisc_device *dev;
110 	unsigned long loops_per_jiffy;
111 };
112 
113 extern struct system_cpuinfo_parisc boot_cpu_data;
114 DECLARE_PER_CPU(struct cpuinfo_parisc, cpu_data);
115 
116 #define CPU_HVERSION ((boot_cpu_data.hversion >> 4) & 0x0FFF)
117 
118 typedef struct {
119 	int seg;
120 } mm_segment_t;
121 
122 #define ARCH_MIN_TASKALIGN	8
123 
124 struct thread_struct {
125 	struct pt_regs regs;
126 	unsigned long  task_size;
127 	unsigned long  map_base;
128 	unsigned long  flags;
129 };
130 
131 #define task_pt_regs(tsk) ((struct pt_regs *)&((tsk)->thread.regs))
132 
133 /* Thread struct flags. */
134 #define PARISC_UAC_NOPRINT	(1UL << 0)	/* see prctl and unaligned.c */
135 #define PARISC_UAC_SIGBUS	(1UL << 1)
136 #define PARISC_KERNEL_DEATH	(1UL << 31)	/* see die_if_kernel()... */
137 
138 #define PARISC_UAC_SHIFT	0
139 #define PARISC_UAC_MASK		(PARISC_UAC_NOPRINT|PARISC_UAC_SIGBUS)
140 
141 #define SET_UNALIGN_CTL(task,value)                                       \
142         ({                                                                \
143         (task)->thread.flags = (((task)->thread.flags & ~PARISC_UAC_MASK) \
144                                 | (((value) << PARISC_UAC_SHIFT) &        \
145                                    PARISC_UAC_MASK));                     \
146         0;                                                                \
147         })
148 
149 #define GET_UNALIGN_CTL(task,addr)                                        \
150         ({                                                                \
151         put_user(((task)->thread.flags & PARISC_UAC_MASK)                 \
152                  >> PARISC_UAC_SHIFT, (int __user *) (addr));             \
153         })
154 
155 #define INIT_THREAD { \
156 	.regs = {	.gr	= { 0, }, \
157 			.fr	= { 0, }, \
158 			.sr	= { 0, }, \
159 			.iasq	= { 0, }, \
160 			.iaoq	= { 0, }, \
161 			.cr27	= 0, \
162 		}, \
163 	.task_size	= DEFAULT_TASK_SIZE, \
164 	.map_base	= DEFAULT_MAP_BASE, \
165 	.flags		= 0 \
166 	}
167 
168 struct task_struct;
169 void show_trace(struct task_struct *task, unsigned long *stack);
170 
171 /*
172  * Start user thread in another space.
173  *
174  * Note that we set both the iaoq and r31 to the new pc. When
175  * the kernel initially calls execve it will return through an
176  * rfi path that will use the values in the iaoq. The execve
177  * syscall path will return through the gateway page, and
178  * that uses r31 to branch to.
179  *
180  * For ELF we clear r23, because the dynamic linker uses it to pass
181  * the address of the finalizer function.
182  *
183  * We also initialize sr3 to an illegal value (illegal for our
184  * implementation, not for the architecture).
185  */
186 typedef unsigned int elf_caddr_t;
187 
188 /* The ELF abi wants things done a "wee bit" differently than
189  * som does.  Supporting this behavior here avoids
190  * having our own version of create_elf_tables.
191  *
192  * Oh, and yes, that is not a typo, we are really passing argc in r25
193  * and argv in r24 (rather than r26 and r25).  This is because that's
194  * where __libc_start_main wants them.
195  *
196  * Duplicated from dl-machine.h for the benefit of readers:
197  *
198  *  Our initial stack layout is rather different from everyone else's
199  *  due to the unique PA-RISC ABI.  As far as I know it looks like
200  *  this:
201 
202    -----------------------------------  (user startup code creates this frame)
203    |         32 bytes of magic       |
204    |---------------------------------|
205    | 32 bytes argument/sp save area  |
206    |---------------------------------| (bprm->p)
207    |	    ELF auxiliary info	     |
208    |         (up to 28 words)        |
209    |---------------------------------|
210    |		   NULL		     |
211    |---------------------------------|
212    |	   Environment pointers	     |
213    |---------------------------------|
214    |		   NULL		     |
215    |---------------------------------|
216    |        Argument pointers        |
217    |---------------------------------| <- argv
218    |          argc (1 word)          |
219    |---------------------------------| <- bprm->exec (HACK!)
220    |         N bytes of slack        |
221    |---------------------------------|
222    |	filename passed to execve    |
223    |---------------------------------| (mm->env_end)
224    |           env strings           |
225    |---------------------------------| (mm->env_start, mm->arg_end)
226    |           arg strings           |
227    |---------------------------------|
228    | additional faked arg strings if |
229    | we're invoked via binfmt_script |
230    |---------------------------------| (mm->arg_start)
231    stack base is at TASK_SIZE - rlim_max.
232 
233 on downward growing arches, it looks like this:
234    stack base at TASK_SIZE
235    | filename passed to execve
236    | env strings
237    | arg strings
238    | faked arg strings
239    | slack
240    | ELF
241    | envps
242    | argvs
243    | argc
244 
245  *  The pleasant part of this is that if we need to skip arguments we
246  *  can just decrement argc and move argv, because the stack pointer
247  *  is utterly unrelated to the location of the environment and
248  *  argument vectors.
249  *
250  * Note that the S/390 people took the easy way out and hacked their
251  * GCC to make the stack grow downwards.
252  *
253  * Final Note: For entry from syscall, the W (wide) bit of the PSW
254  * is stuffed into the lowest bit of the user sp (%r30), so we fill
255  * it in here from the current->personality
256  */
257 
258 #ifdef CONFIG_64BIT
259 #define USER_WIDE_MODE	(!test_thread_flag(TIF_32BIT))
260 #else
261 #define USER_WIDE_MODE	0
262 #endif
263 
264 #define start_thread(regs, new_pc, new_sp) do {		\
265 	elf_addr_t *sp = (elf_addr_t *)new_sp;		\
266 	__u32 spaceid = (__u32)current->mm->context;	\
267 	elf_addr_t pc = (elf_addr_t)new_pc | 3;		\
268 	elf_caddr_t *argv = (elf_caddr_t *)bprm->exec + 1;	\
269 							\
270 	regs->iasq[0] = spaceid;			\
271 	regs->iasq[1] = spaceid;			\
272 	regs->iaoq[0] = pc;				\
273 	regs->iaoq[1] = pc + 4;                         \
274 	regs->sr[2] = LINUX_GATEWAY_SPACE;              \
275 	regs->sr[3] = 0xffff;				\
276 	regs->sr[4] = spaceid;				\
277 	regs->sr[5] = spaceid;				\
278 	regs->sr[6] = spaceid;				\
279 	regs->sr[7] = spaceid;				\
280 	regs->gr[ 0] = USER_PSW | (USER_WIDE_MODE ? PSW_W : 0); \
281 	regs->fr[ 0] = 0LL;                            	\
282 	regs->fr[ 1] = 0LL;                            	\
283 	regs->fr[ 2] = 0LL;                            	\
284 	regs->fr[ 3] = 0LL;                            	\
285 	regs->gr[30] = (((unsigned long)sp + 63) &~ 63) | (USER_WIDE_MODE ? 1 : 0); \
286 	regs->gr[31] = pc;				\
287 							\
288 	get_user(regs->gr[25], (argv - 1));		\
289 	regs->gr[24] = (long) argv;			\
290 	regs->gr[23] = 0;				\
291 } while(0)
292 
293 struct task_struct;
294 struct mm_struct;
295 
296 /* Free all resources held by a thread. */
297 extern void release_thread(struct task_struct *);
298 
299 extern unsigned long get_wchan(struct task_struct *p);
300 
301 #define KSTK_EIP(tsk)	((tsk)->thread.regs.iaoq[0])
302 #define KSTK_ESP(tsk)	((tsk)->thread.regs.gr[30])
303 
304 #define cpu_relax()	barrier()
305 
306 /*
307  * parisc_requires_coherency() is used to identify the combined VIPT/PIPT
308  * cached CPUs which require a guarantee of coherency (no inequivalent aliases
309  * with different data, whether clean or not) to operate
310  */
311 #ifdef CONFIG_PA8X00
312 extern int _parisc_requires_coherency;
313 #define parisc_requires_coherency()	_parisc_requires_coherency
314 #else
315 #define parisc_requires_coherency()	(0)
316 #endif
317 
318 #endif /* __ASSEMBLY__ */
319 
320 #endif /* __ASM_PARISC_PROCESSOR_H */
321