xref: /openbmc/linux/arch/s390/include/asm/processor.h (revision 95e9fd10)
1 /*
2  *  S390 version
3  *    Copyright IBM Corp. 1999
4  *    Author(s): Hartmut Penner (hp@de.ibm.com),
5  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
6  *
7  *  Derived from "include/asm-i386/processor.h"
8  *    Copyright (C) 1994, Linus Torvalds
9  */
10 
11 #ifndef __ASM_S390_PROCESSOR_H
12 #define __ASM_S390_PROCESSOR_H
13 
14 #include <linux/linkage.h>
15 #include <linux/irqflags.h>
16 #include <asm/cpu.h>
17 #include <asm/page.h>
18 #include <asm/ptrace.h>
19 #include <asm/setup.h>
20 
21 /*
22  * Default implementation of macro that returns current
23  * instruction pointer ("program counter").
24  */
25 #define current_text_addr() ({ void *pc; asm("basr %0,0" : "=a" (pc)); pc; })
26 
27 static inline void get_cpu_id(struct cpuid *ptr)
28 {
29 	asm volatile("stidp %0" : "=Q" (*ptr));
30 }
31 
32 extern void s390_adjust_jiffies(void);
33 extern const struct seq_operations cpuinfo_op;
34 extern int sysctl_ieee_emulation_warnings;
35 
36 /*
37  * User space process size: 2GB for 31 bit, 4TB or 8PT for 64 bit.
38  */
39 #ifndef CONFIG_64BIT
40 
41 #define TASK_SIZE		(1UL << 31)
42 #define TASK_UNMAPPED_BASE	(1UL << 30)
43 
44 #else /* CONFIG_64BIT */
45 
46 #define TASK_SIZE_OF(tsk)	((tsk)->mm->context.asce_limit)
47 #define TASK_UNMAPPED_BASE	(test_thread_flag(TIF_31BIT) ? \
48 					(1UL << 30) : (1UL << 41))
49 #define TASK_SIZE		TASK_SIZE_OF(current)
50 
51 #endif /* CONFIG_64BIT */
52 
53 #ifndef CONFIG_64BIT
54 #define STACK_TOP		(1UL << 31)
55 #define STACK_TOP_MAX		(1UL << 31)
56 #else /* CONFIG_64BIT */
57 #define STACK_TOP		(1UL << (test_thread_flag(TIF_31BIT) ? 31:42))
58 #define STACK_TOP_MAX		(1UL << 42)
59 #endif /* CONFIG_64BIT */
60 
61 #define HAVE_ARCH_PICK_MMAP_LAYOUT
62 
63 typedef struct {
64         __u32 ar4;
65 } mm_segment_t;
66 
67 /*
68  * Thread structure
69  */
70 struct thread_struct {
71 	s390_fp_regs fp_regs;
72 	unsigned int  acrs[NUM_ACRS];
73         unsigned long ksp;              /* kernel stack pointer             */
74 	mm_segment_t mm_segment;
75 	unsigned long gmap_addr;	/* address of last gmap fault. */
76 	struct per_regs per_user;	/* User specified PER registers */
77 	struct per_event per_event;	/* Cause of the last PER trap */
78         /* pfault_wait is used to block the process on a pfault event */
79 	unsigned long pfault_wait;
80 	struct list_head list;
81 };
82 
83 typedef struct thread_struct thread_struct;
84 
85 /*
86  * Stack layout of a C stack frame.
87  */
88 #ifndef __PACK_STACK
89 struct stack_frame {
90 	unsigned long back_chain;
91 	unsigned long empty1[5];
92 	unsigned long gprs[10];
93 	unsigned int  empty2[8];
94 };
95 #else
96 struct stack_frame {
97 	unsigned long empty1[5];
98 	unsigned int  empty2[8];
99 	unsigned long gprs[10];
100 	unsigned long back_chain;
101 };
102 #endif
103 
104 #define ARCH_MIN_TASKALIGN	8
105 
106 #define INIT_THREAD {							\
107 	.ksp = sizeof(init_stack) + (unsigned long) &init_stack,	\
108 }
109 
110 /*
111  * Do necessary setup to start up a new thread.
112  */
113 #define start_thread(regs, new_psw, new_stackp) do {			\
114 	regs->psw.mask	= psw_user_bits | PSW_MASK_EA | PSW_MASK_BA;	\
115 	regs->psw.addr	= new_psw | PSW_ADDR_AMODE;			\
116 	regs->gprs[15]	= new_stackp;					\
117 } while (0)
118 
119 #define start_thread31(regs, new_psw, new_stackp) do {			\
120 	regs->psw.mask	= psw_user_bits | PSW_MASK_BA;			\
121 	regs->psw.addr	= new_psw | PSW_ADDR_AMODE;			\
122 	regs->gprs[15]	= new_stackp;					\
123 	__tlb_flush_mm(current->mm);					\
124 	crst_table_downgrade(current->mm, 1UL << 31);			\
125 	update_mm(current->mm, current);				\
126 } while (0)
127 
128 /* Forward declaration, a strange C thing */
129 struct task_struct;
130 struct mm_struct;
131 struct seq_file;
132 
133 /* Free all resources held by a thread. */
134 extern void release_thread(struct task_struct *);
135 extern int kernel_thread(int (*fn)(void *), void * arg, unsigned long flags);
136 
137 /*
138  * Return saved PC of a blocked thread.
139  */
140 extern unsigned long thread_saved_pc(struct task_struct *t);
141 
142 extern void show_code(struct pt_regs *regs);
143 
144 unsigned long get_wchan(struct task_struct *p);
145 #define task_pt_regs(tsk) ((struct pt_regs *) \
146         (task_stack_page(tsk) + THREAD_SIZE) - 1)
147 #define KSTK_EIP(tsk)	(task_pt_regs(tsk)->psw.addr)
148 #define KSTK_ESP(tsk)	(task_pt_regs(tsk)->gprs[15])
149 
150 static inline unsigned short stap(void)
151 {
152 	unsigned short cpu_address;
153 
154 	asm volatile("stap %0" : "=m" (cpu_address));
155 	return cpu_address;
156 }
157 
158 /*
159  * Give up the time slice of the virtual PU.
160  */
161 static inline void cpu_relax(void)
162 {
163 	if (MACHINE_HAS_DIAG44)
164 		asm volatile("diag 0,0,68");
165 	barrier();
166 }
167 
168 static inline void psw_set_key(unsigned int key)
169 {
170 	asm volatile("spka 0(%0)" : : "d" (key));
171 }
172 
173 /*
174  * Set PSW to specified value.
175  */
176 static inline void __load_psw(psw_t psw)
177 {
178 #ifndef CONFIG_64BIT
179 	asm volatile("lpsw  %0" : : "Q" (psw) : "cc");
180 #else
181 	asm volatile("lpswe %0" : : "Q" (psw) : "cc");
182 #endif
183 }
184 
185 /*
186  * Set PSW mask to specified value, while leaving the
187  * PSW addr pointing to the next instruction.
188  */
189 static inline void __load_psw_mask (unsigned long mask)
190 {
191 	unsigned long addr;
192 	psw_t psw;
193 
194 	psw.mask = mask;
195 
196 #ifndef CONFIG_64BIT
197 	asm volatile(
198 		"	basr	%0,0\n"
199 		"0:	ahi	%0,1f-0b\n"
200 		"	st	%0,%O1+4(%R1)\n"
201 		"	lpsw	%1\n"
202 		"1:"
203 		: "=&d" (addr), "=Q" (psw) : "Q" (psw) : "memory", "cc");
204 #else /* CONFIG_64BIT */
205 	asm volatile(
206 		"	larl	%0,1f\n"
207 		"	stg	%0,%O1+8(%R1)\n"
208 		"	lpswe	%1\n"
209 		"1:"
210 		: "=&d" (addr), "=Q" (psw) : "Q" (psw) : "memory", "cc");
211 #endif /* CONFIG_64BIT */
212 }
213 
214 /*
215  * Rewind PSW instruction address by specified number of bytes.
216  */
217 static inline unsigned long __rewind_psw(psw_t psw, unsigned long ilc)
218 {
219 #ifndef CONFIG_64BIT
220 	if (psw.addr & PSW_ADDR_AMODE)
221 		/* 31 bit mode */
222 		return (psw.addr - ilc) | PSW_ADDR_AMODE;
223 	/* 24 bit mode */
224 	return (psw.addr - ilc) & ((1UL << 24) - 1);
225 #else
226 	unsigned long mask;
227 
228 	mask = (psw.mask & PSW_MASK_EA) ? -1UL :
229 	       (psw.mask & PSW_MASK_BA) ? (1UL << 31) - 1 :
230 					  (1UL << 24) - 1;
231 	return (psw.addr - ilc) & mask;
232 #endif
233 }
234 
235 /*
236  * Function to drop a processor into disabled wait state
237  */
238 static inline void __noreturn disabled_wait(unsigned long code)
239 {
240         unsigned long ctl_buf;
241         psw_t dw_psw;
242 
243 	dw_psw.mask = PSW_MASK_BASE | PSW_MASK_WAIT | PSW_MASK_BA | PSW_MASK_EA;
244         dw_psw.addr = code;
245         /*
246          * Store status and then load disabled wait psw,
247          * the processor is dead afterwards
248          */
249 #ifndef CONFIG_64BIT
250 	asm volatile(
251 		"	stctl	0,0,0(%2)\n"
252 		"	ni	0(%2),0xef\n"	/* switch off protection */
253 		"	lctl	0,0,0(%2)\n"
254 		"	stpt	0xd8\n"		/* store timer */
255 		"	stckc	0xe0\n"		/* store clock comparator */
256 		"	stpx	0x108\n"	/* store prefix register */
257 		"	stam	0,15,0x120\n"	/* store access registers */
258 		"	std	0,0x160\n"	/* store f0 */
259 		"	std	2,0x168\n"	/* store f2 */
260 		"	std	4,0x170\n"	/* store f4 */
261 		"	std	6,0x178\n"	/* store f6 */
262 		"	stm	0,15,0x180\n"	/* store general registers */
263 		"	stctl	0,15,0x1c0\n"	/* store control registers */
264 		"	oi	0x1c0,0x10\n"	/* fake protection bit */
265 		"	lpsw	0(%1)"
266 		: "=m" (ctl_buf)
267 		: "a" (&dw_psw), "a" (&ctl_buf), "m" (dw_psw) : "cc");
268 #else /* CONFIG_64BIT */
269 	asm volatile(
270 		"	stctg	0,0,0(%2)\n"
271 		"	ni	4(%2),0xef\n"	/* switch off protection */
272 		"	lctlg	0,0,0(%2)\n"
273 		"	lghi	1,0x1000\n"
274 		"	stpt	0x328(1)\n"	/* store timer */
275 		"	stckc	0x330(1)\n"	/* store clock comparator */
276 		"	stpx	0x318(1)\n"	/* store prefix register */
277 		"	stam	0,15,0x340(1)\n"/* store access registers */
278 		"	stfpc	0x31c(1)\n"	/* store fpu control */
279 		"	std	0,0x200(1)\n"	/* store f0 */
280 		"	std	1,0x208(1)\n"	/* store f1 */
281 		"	std	2,0x210(1)\n"	/* store f2 */
282 		"	std	3,0x218(1)\n"	/* store f3 */
283 		"	std	4,0x220(1)\n"	/* store f4 */
284 		"	std	5,0x228(1)\n"	/* store f5 */
285 		"	std	6,0x230(1)\n"	/* store f6 */
286 		"	std	7,0x238(1)\n"	/* store f7 */
287 		"	std	8,0x240(1)\n"	/* store f8 */
288 		"	std	9,0x248(1)\n"	/* store f9 */
289 		"	std	10,0x250(1)\n"	/* store f10 */
290 		"	std	11,0x258(1)\n"	/* store f11 */
291 		"	std	12,0x260(1)\n"	/* store f12 */
292 		"	std	13,0x268(1)\n"	/* store f13 */
293 		"	std	14,0x270(1)\n"	/* store f14 */
294 		"	std	15,0x278(1)\n"	/* store f15 */
295 		"	stmg	0,15,0x280(1)\n"/* store general registers */
296 		"	stctg	0,15,0x380(1)\n"/* store control registers */
297 		"	oi	0x384(1),0x10\n"/* fake protection bit */
298 		"	lpswe	0(%1)"
299 		: "=m" (ctl_buf)
300 		: "a" (&dw_psw), "a" (&ctl_buf), "m" (dw_psw) : "cc", "0", "1");
301 #endif /* CONFIG_64BIT */
302 	while (1);
303 }
304 
305 /*
306  * Use to set psw mask except for the first byte which
307  * won't be changed by this function.
308  */
309 static inline void
310 __set_psw_mask(unsigned long mask)
311 {
312 	__load_psw_mask(mask | (arch_local_save_flags() & ~(-1UL >> 8)));
313 }
314 
315 #define local_mcck_enable() \
316 	__set_psw_mask(psw_kernel_bits | PSW_MASK_DAT | PSW_MASK_MCHECK)
317 #define local_mcck_disable() \
318 	__set_psw_mask(psw_kernel_bits | PSW_MASK_DAT)
319 
320 /*
321  * Basic Machine Check/Program Check Handler.
322  */
323 
324 extern void s390_base_mcck_handler(void);
325 extern void s390_base_pgm_handler(void);
326 extern void s390_base_ext_handler(void);
327 
328 extern void (*s390_base_mcck_handler_fn)(void);
329 extern void (*s390_base_pgm_handler_fn)(void);
330 extern void (*s390_base_ext_handler_fn)(void);
331 
332 #define ARCH_LOW_ADDRESS_LIMIT	0x7fffffffUL
333 
334 /*
335  * Helper macro for exception table entries
336  */
337 #ifndef CONFIG_64BIT
338 #define EX_TABLE(_fault,_target)			\
339 	".section __ex_table,\"a\"\n"			\
340 	"	.align 4\n"				\
341 	"	.long  " #_fault "," #_target "\n"	\
342 	".previous\n"
343 #else
344 #define EX_TABLE(_fault,_target)			\
345 	".section __ex_table,\"a\"\n"			\
346 	"	.align 8\n"				\
347 	"	.quad  " #_fault "," #_target "\n"	\
348 	".previous\n"
349 #endif
350 
351 extern int memcpy_real(void *, void *, size_t);
352 extern void memcpy_absolute(void *, void *, size_t);
353 
354 #define mem_assign_absolute(dest, val) {			\
355 	__typeof__(dest) __tmp = (val);				\
356 								\
357 	BUILD_BUG_ON(sizeof(__tmp) != sizeof(val));		\
358 	memcpy_absolute(&(dest), &__tmp, sizeof(__tmp));	\
359 }
360 
361 #endif                                 /* __ASM_S390_PROCESSOR_H           */
362