xref: /openbmc/linux/arch/s390/include/asm/processor.h (revision a06c488d)
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/const.h>
15 
16 #define CIF_MCCK_PENDING	0	/* machine check handling is pending */
17 #define CIF_ASCE		1	/* user asce needs fixup / uaccess */
18 #define CIF_NOHZ_DELAY		2	/* delay HZ disable for a tick */
19 #define CIF_FPU			3	/* restore FPU registers */
20 #define CIF_IGNORE_IRQ		4	/* ignore interrupt (for udelay) */
21 #define CIF_ENABLED_WAIT	5	/* in enabled wait state */
22 
23 #define _CIF_MCCK_PENDING	_BITUL(CIF_MCCK_PENDING)
24 #define _CIF_ASCE		_BITUL(CIF_ASCE)
25 #define _CIF_NOHZ_DELAY		_BITUL(CIF_NOHZ_DELAY)
26 #define _CIF_FPU		_BITUL(CIF_FPU)
27 #define _CIF_IGNORE_IRQ		_BITUL(CIF_IGNORE_IRQ)
28 #define _CIF_ENABLED_WAIT	_BITUL(CIF_ENABLED_WAIT)
29 
30 #ifndef __ASSEMBLY__
31 
32 #include <linux/linkage.h>
33 #include <linux/irqflags.h>
34 #include <asm/cpu.h>
35 #include <asm/page.h>
36 #include <asm/ptrace.h>
37 #include <asm/setup.h>
38 #include <asm/runtime_instr.h>
39 #include <asm/fpu/types.h>
40 #include <asm/fpu/internal.h>
41 
42 static inline void set_cpu_flag(int flag)
43 {
44 	S390_lowcore.cpu_flags |= (1UL << flag);
45 }
46 
47 static inline void clear_cpu_flag(int flag)
48 {
49 	S390_lowcore.cpu_flags &= ~(1UL << flag);
50 }
51 
52 static inline int test_cpu_flag(int flag)
53 {
54 	return !!(S390_lowcore.cpu_flags & (1UL << flag));
55 }
56 
57 /*
58  * Test CIF flag of another CPU. The caller needs to ensure that
59  * CPU hotplug can not happen, e.g. by disabling preemption.
60  */
61 static inline int test_cpu_flag_of(int flag, int cpu)
62 {
63 	struct lowcore *lc = lowcore_ptr[cpu];
64 	return !!(lc->cpu_flags & (1UL << flag));
65 }
66 
67 #define arch_needs_cpu() test_cpu_flag(CIF_NOHZ_DELAY)
68 
69 /*
70  * Default implementation of macro that returns current
71  * instruction pointer ("program counter").
72  */
73 #define current_text_addr() ({ void *pc; asm("basr %0,0" : "=a" (pc)); pc; })
74 
75 static inline void get_cpu_id(struct cpuid *ptr)
76 {
77 	asm volatile("stidp %0" : "=Q" (*ptr));
78 }
79 
80 extern void s390_adjust_jiffies(void);
81 extern const struct seq_operations cpuinfo_op;
82 extern int sysctl_ieee_emulation_warnings;
83 extern void execve_tail(void);
84 
85 /*
86  * User space process size: 2GB for 31 bit, 4TB or 8PT for 64 bit.
87  */
88 
89 #define TASK_SIZE_OF(tsk)	((tsk)->mm->context.asce_limit)
90 #define TASK_UNMAPPED_BASE	(test_thread_flag(TIF_31BIT) ? \
91 					(1UL << 30) : (1UL << 41))
92 #define TASK_SIZE		TASK_SIZE_OF(current)
93 #define TASK_MAX_SIZE		(1UL << 53)
94 
95 #define STACK_TOP		(1UL << (test_thread_flag(TIF_31BIT) ? 31:42))
96 #define STACK_TOP_MAX		(1UL << 42)
97 
98 #define HAVE_ARCH_PICK_MMAP_LAYOUT
99 
100 typedef struct {
101         __u32 ar4;
102 } mm_segment_t;
103 
104 /*
105  * Thread structure
106  */
107 struct thread_struct {
108 	struct fpu fpu;			/* FP and VX register save area */
109 	unsigned int  acrs[NUM_ACRS];
110         unsigned long ksp;              /* kernel stack pointer             */
111 	mm_segment_t mm_segment;
112 	unsigned long gmap_addr;	/* address of last gmap fault. */
113 	unsigned int gmap_pfault;	/* signal of a pending guest pfault */
114 	struct per_regs per_user;	/* User specified PER registers */
115 	struct per_event per_event;	/* Cause of the last PER trap */
116 	unsigned long per_flags;	/* Flags to control debug behavior */
117         /* pfault_wait is used to block the process on a pfault event */
118 	unsigned long pfault_wait;
119 	struct list_head list;
120 	/* cpu runtime instrumentation */
121 	struct runtime_instr_cb *ri_cb;
122 	unsigned char trap_tdb[256];	/* Transaction abort diagnose block */
123 };
124 
125 /* Flag to disable transactions. */
126 #define PER_FLAG_NO_TE			1UL
127 /* Flag to enable random transaction aborts. */
128 #define PER_FLAG_TE_ABORT_RAND		2UL
129 /* Flag to specify random transaction abort mode:
130  * - abort each transaction at a random instruction before TEND if set.
131  * - abort random transactions at a random instruction if cleared.
132  */
133 #define PER_FLAG_TE_ABORT_RAND_TEND	4UL
134 
135 typedef struct thread_struct thread_struct;
136 
137 /*
138  * Stack layout of a C stack frame.
139  */
140 #ifndef __PACK_STACK
141 struct stack_frame {
142 	unsigned long back_chain;
143 	unsigned long empty1[5];
144 	unsigned long gprs[10];
145 	unsigned int  empty2[8];
146 };
147 #else
148 struct stack_frame {
149 	unsigned long empty1[5];
150 	unsigned int  empty2[8];
151 	unsigned long gprs[10];
152 	unsigned long back_chain;
153 };
154 #endif
155 
156 #define ARCH_MIN_TASKALIGN	8
157 
158 extern __vector128 init_task_fpu_regs[__NUM_VXRS];
159 #define INIT_THREAD {							\
160 	.ksp = sizeof(init_stack) + (unsigned long) &init_stack,	\
161 	.fpu.regs = (void *)&init_task_fpu_regs,			\
162 }
163 
164 /*
165  * Do necessary setup to start up a new thread.
166  */
167 #define start_thread(regs, new_psw, new_stackp) do {			\
168 	regs->psw.mask	= PSW_USER_BITS | PSW_MASK_EA | PSW_MASK_BA;	\
169 	regs->psw.addr	= new_psw | PSW_ADDR_AMODE;			\
170 	regs->gprs[15]	= new_stackp;					\
171 	execve_tail();							\
172 } while (0)
173 
174 #define start_thread31(regs, new_psw, new_stackp) do {			\
175 	regs->psw.mask	= PSW_USER_BITS | PSW_MASK_BA;			\
176 	regs->psw.addr	= new_psw | PSW_ADDR_AMODE;			\
177 	regs->gprs[15]	= new_stackp;					\
178 	crst_table_downgrade(current->mm, 1UL << 31);			\
179 	execve_tail();							\
180 } while (0)
181 
182 /* Forward declaration, a strange C thing */
183 struct task_struct;
184 struct mm_struct;
185 struct seq_file;
186 
187 void show_cacheinfo(struct seq_file *m);
188 
189 /* Free all resources held by a thread. */
190 extern void release_thread(struct task_struct *);
191 
192 /*
193  * Return saved PC of a blocked thread.
194  */
195 extern unsigned long thread_saved_pc(struct task_struct *t);
196 
197 unsigned long get_wchan(struct task_struct *p);
198 #define task_pt_regs(tsk) ((struct pt_regs *) \
199         (task_stack_page(tsk) + THREAD_SIZE) - 1)
200 #define KSTK_EIP(tsk)	(task_pt_regs(tsk)->psw.addr)
201 #define KSTK_ESP(tsk)	(task_pt_regs(tsk)->gprs[15])
202 
203 /* Has task runtime instrumentation enabled ? */
204 #define is_ri_task(tsk) (!!(tsk)->thread.ri_cb)
205 
206 static inline unsigned short stap(void)
207 {
208 	unsigned short cpu_address;
209 
210 	asm volatile("stap %0" : "=m" (cpu_address));
211 	return cpu_address;
212 }
213 
214 /*
215  * Give up the time slice of the virtual PU.
216  */
217 void cpu_relax(void);
218 
219 #define cpu_relax_lowlatency()  barrier()
220 
221 static inline void psw_set_key(unsigned int key)
222 {
223 	asm volatile("spka 0(%0)" : : "d" (key));
224 }
225 
226 /*
227  * Set PSW to specified value.
228  */
229 static inline void __load_psw(psw_t psw)
230 {
231 	asm volatile("lpswe %0" : : "Q" (psw) : "cc");
232 }
233 
234 /*
235  * Set PSW mask to specified value, while leaving the
236  * PSW addr pointing to the next instruction.
237  */
238 static inline void __load_psw_mask(unsigned long mask)
239 {
240 	unsigned long addr;
241 	psw_t psw;
242 
243 	psw.mask = mask;
244 
245 	asm volatile(
246 		"	larl	%0,1f\n"
247 		"	stg	%0,%O1+8(%R1)\n"
248 		"	lpswe	%1\n"
249 		"1:"
250 		: "=&d" (addr), "=Q" (psw) : "Q" (psw) : "memory", "cc");
251 }
252 
253 /*
254  * Extract current PSW mask
255  */
256 static inline unsigned long __extract_psw(void)
257 {
258 	unsigned int reg1, reg2;
259 
260 	asm volatile("epsw %0,%1" : "=d" (reg1), "=a" (reg2));
261 	return (((unsigned long) reg1) << 32) | ((unsigned long) reg2);
262 }
263 
264 static inline void local_mcck_enable(void)
265 {
266 	__load_psw_mask(__extract_psw() | PSW_MASK_MCHECK);
267 }
268 
269 static inline void local_mcck_disable(void)
270 {
271 	__load_psw_mask(__extract_psw() & ~PSW_MASK_MCHECK);
272 }
273 
274 /*
275  * Rewind PSW instruction address by specified number of bytes.
276  */
277 static inline unsigned long __rewind_psw(psw_t psw, unsigned long ilc)
278 {
279 	unsigned long mask;
280 
281 	mask = (psw.mask & PSW_MASK_EA) ? -1UL :
282 	       (psw.mask & PSW_MASK_BA) ? (1UL << 31) - 1 :
283 					  (1UL << 24) - 1;
284 	return (psw.addr - ilc) & mask;
285 }
286 
287 /*
288  * Function to stop a processor until the next interrupt occurs
289  */
290 void enabled_wait(void);
291 
292 /*
293  * Function to drop a processor into disabled wait state
294  */
295 static inline void __noreturn disabled_wait(unsigned long code)
296 {
297 	psw_t psw;
298 
299 	psw.mask = PSW_MASK_BASE | PSW_MASK_WAIT | PSW_MASK_BA | PSW_MASK_EA;
300 	psw.addr = code;
301 	__load_psw(psw);
302 	while (1);
303 }
304 
305 /*
306  * Basic Machine Check/Program Check Handler.
307  */
308 
309 extern void s390_base_mcck_handler(void);
310 extern void s390_base_pgm_handler(void);
311 extern void s390_base_ext_handler(void);
312 
313 extern void (*s390_base_mcck_handler_fn)(void);
314 extern void (*s390_base_pgm_handler_fn)(void);
315 extern void (*s390_base_ext_handler_fn)(void);
316 
317 #define ARCH_LOW_ADDRESS_LIMIT	0x7fffffffUL
318 
319 extern int memcpy_real(void *, void *, size_t);
320 extern void memcpy_absolute(void *, void *, size_t);
321 
322 #define mem_assign_absolute(dest, val) {			\
323 	__typeof__(dest) __tmp = (val);				\
324 								\
325 	BUILD_BUG_ON(sizeof(__tmp) != sizeof(val));		\
326 	memcpy_absolute(&(dest), &__tmp, sizeof(__tmp));	\
327 }
328 
329 #endif /* __ASSEMBLY__ */
330 
331 #endif /* __ASM_S390_PROCESSOR_H */
332