xref: /openbmc/linux/arch/s390/include/asm/processor.h (revision d87c25e8)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3  *  S390 version
4  *    Copyright IBM Corp. 1999
5  *    Author(s): Hartmut Penner (hp@de.ibm.com),
6  *               Martin Schwidefsky (schwidefsky@de.ibm.com)
7  *
8  *  Derived from "include/asm-i386/processor.h"
9  *    Copyright (C) 1994, Linus Torvalds
10  */
11 
12 #ifndef __ASM_S390_PROCESSOR_H
13 #define __ASM_S390_PROCESSOR_H
14 
15 #include <linux/bits.h>
16 
17 #define CIF_NOHZ_DELAY		2	/* delay HZ disable for a tick */
18 #define CIF_FPU			3	/* restore FPU registers */
19 #define CIF_ENABLED_WAIT	5	/* in enabled wait state */
20 #define CIF_MCCK_GUEST		6	/* machine check happening in guest */
21 #define CIF_DEDICATED_CPU	7	/* this CPU is dedicated */
22 
23 #define _CIF_NOHZ_DELAY		BIT(CIF_NOHZ_DELAY)
24 #define _CIF_FPU		BIT(CIF_FPU)
25 #define _CIF_ENABLED_WAIT	BIT(CIF_ENABLED_WAIT)
26 #define _CIF_MCCK_GUEST		BIT(CIF_MCCK_GUEST)
27 #define _CIF_DEDICATED_CPU	BIT(CIF_DEDICATED_CPU)
28 
29 #define RESTART_FLAG_CTLREGS	_AC(1 << 0, U)
30 
31 #ifndef __ASSEMBLY__
32 
33 #include <linux/cpumask.h>
34 #include <linux/linkage.h>
35 #include <linux/irqflags.h>
36 #include <asm/cpu.h>
37 #include <asm/page.h>
38 #include <asm/ptrace.h>
39 #include <asm/setup.h>
40 #include <asm/runtime_instr.h>
41 #include <asm/fpu/types.h>
42 #include <asm/fpu/internal.h>
43 #include <asm/irqflags.h>
44 
45 typedef long (*sys_call_ptr_t)(struct pt_regs *regs);
46 
47 static inline void set_cpu_flag(int flag)
48 {
49 	S390_lowcore.cpu_flags |= (1UL << flag);
50 }
51 
52 static inline void clear_cpu_flag(int flag)
53 {
54 	S390_lowcore.cpu_flags &= ~(1UL << flag);
55 }
56 
57 static inline int test_cpu_flag(int flag)
58 {
59 	return !!(S390_lowcore.cpu_flags & (1UL << flag));
60 }
61 
62 /*
63  * Test CIF flag of another CPU. The caller needs to ensure that
64  * CPU hotplug can not happen, e.g. by disabling preemption.
65  */
66 static inline int test_cpu_flag_of(int flag, int cpu)
67 {
68 	struct lowcore *lc = lowcore_ptr[cpu];
69 	return !!(lc->cpu_flags & (1UL << flag));
70 }
71 
72 #define arch_needs_cpu() test_cpu_flag(CIF_NOHZ_DELAY)
73 
74 static inline void get_cpu_id(struct cpuid *ptr)
75 {
76 	asm volatile("stidp %0" : "=Q" (*ptr));
77 }
78 
79 void s390_adjust_jiffies(void);
80 void s390_update_cpu_mhz(void);
81 void cpu_detect_mhz_feature(void);
82 
83 extern const struct seq_operations cpuinfo_op;
84 extern void execve_tail(void);
85 extern void __bpon(void);
86 
87 /*
88  * User space process size: 2GB for 31 bit, 4TB or 8PT for 64 bit.
89  */
90 
91 #define TASK_SIZE		(test_thread_flag(TIF_31BIT) ? \
92 					_REGION3_SIZE : TASK_SIZE_MAX)
93 #define TASK_UNMAPPED_BASE	(test_thread_flag(TIF_31BIT) ? \
94 					(_REGION3_SIZE >> 1) : (_REGION2_SIZE >> 1))
95 #define TASK_SIZE_MAX		(-PAGE_SIZE)
96 
97 #define STACK_TOP		(test_thread_flag(TIF_31BIT) ? \
98 					_REGION3_SIZE : _REGION2_SIZE)
99 #define STACK_TOP_MAX		_REGION2_SIZE
100 
101 #define HAVE_ARCH_PICK_MMAP_LAYOUT
102 
103 /*
104  * Thread structure
105  */
106 struct thread_struct {
107 	unsigned int  acrs[NUM_ACRS];
108 	unsigned long ksp;			/* kernel stack pointer */
109 	unsigned long user_timer;		/* task cputime in user space */
110 	unsigned long guest_timer;		/* task cputime in kvm guest */
111 	unsigned long system_timer;		/* task cputime in kernel space */
112 	unsigned long hardirq_timer;		/* task cputime in hardirq context */
113 	unsigned long softirq_timer;		/* task cputime in softirq context */
114 	const sys_call_ptr_t *sys_call_table;	/* system call table address */
115 	unsigned long gmap_addr;		/* address of last gmap fault. */
116 	unsigned int gmap_write_flag;		/* gmap fault write indication */
117 	unsigned int gmap_int_code;		/* int code of last gmap fault */
118 	unsigned int gmap_pfault;		/* signal of a pending guest pfault */
119 
120 	/* Per-thread information related to debugging */
121 	struct per_regs per_user;		/* User specified PER registers */
122 	struct per_event per_event;		/* Cause of the last PER trap */
123 	unsigned long per_flags;		/* Flags to control debug behavior */
124 	unsigned int system_call;		/* system call number in signal */
125 	unsigned long last_break;		/* last breaking-event-address. */
126 	/* pfault_wait is used to block the process on a pfault event */
127 	unsigned long pfault_wait;
128 	struct list_head list;
129 	/* cpu runtime instrumentation */
130 	struct runtime_instr_cb *ri_cb;
131 	struct gs_cb *gs_cb;			/* Current guarded storage cb */
132 	struct gs_cb *gs_bc_cb;			/* Broadcast guarded storage cb */
133 	struct pgm_tdb trap_tdb;		/* Transaction abort diagnose block */
134 	/*
135 	 * Warning: 'fpu' is dynamically-sized. It *MUST* be at
136 	 * the end.
137 	 */
138 	struct fpu fpu;			/* FP and VX register save area */
139 };
140 
141 /* Flag to disable transactions. */
142 #define PER_FLAG_NO_TE			1UL
143 /* Flag to enable random transaction aborts. */
144 #define PER_FLAG_TE_ABORT_RAND		2UL
145 /* Flag to specify random transaction abort mode:
146  * - abort each transaction at a random instruction before TEND if set.
147  * - abort random transactions at a random instruction if cleared.
148  */
149 #define PER_FLAG_TE_ABORT_RAND_TEND	4UL
150 
151 typedef struct thread_struct thread_struct;
152 
153 #define ARCH_MIN_TASKALIGN	8
154 
155 #define INIT_THREAD {							\
156 	.ksp = sizeof(init_stack) + (unsigned long) &init_stack,	\
157 	.fpu.regs = (void *) init_task.thread.fpu.fprs,			\
158 	.last_break = 1,						\
159 }
160 
161 /*
162  * Do necessary setup to start up a new thread.
163  */
164 #define start_thread(regs, new_psw, new_stackp) do {			\
165 	regs->psw.mask	= PSW_USER_BITS | PSW_MASK_EA | PSW_MASK_BA;	\
166 	regs->psw.addr	= new_psw;					\
167 	regs->gprs[15]	= new_stackp;					\
168 	execve_tail();							\
169 } while (0)
170 
171 #define start_thread31(regs, new_psw, new_stackp) do {			\
172 	regs->psw.mask	= PSW_USER_BITS | PSW_MASK_BA;			\
173 	regs->psw.addr	= new_psw;					\
174 	regs->gprs[15]	= new_stackp;					\
175 	execve_tail();							\
176 } while (0)
177 
178 /* Forward declaration, a strange C thing */
179 struct task_struct;
180 struct mm_struct;
181 struct seq_file;
182 struct pt_regs;
183 
184 void show_registers(struct pt_regs *regs);
185 void show_cacheinfo(struct seq_file *m);
186 
187 /* Free all resources held by a thread. */
188 static inline void release_thread(struct task_struct *tsk) { }
189 
190 /* Free guarded storage control block */
191 void guarded_storage_release(struct task_struct *tsk);
192 void gs_load_bc_cb(struct pt_regs *regs);
193 
194 unsigned long __get_wchan(struct task_struct *p);
195 #define task_pt_regs(tsk) ((struct pt_regs *) \
196         (task_stack_page(tsk) + THREAD_SIZE) - 1)
197 #define KSTK_EIP(tsk)	(task_pt_regs(tsk)->psw.addr)
198 #define KSTK_ESP(tsk)	(task_pt_regs(tsk)->gprs[15])
199 
200 /* Has task runtime instrumentation enabled ? */
201 #define is_ri_task(tsk) (!!(tsk)->thread.ri_cb)
202 
203 static __always_inline unsigned long current_stack_pointer(void)
204 {
205 	unsigned long sp;
206 
207 	asm volatile("la %0,0(15)" : "=a" (sp));
208 	return sp;
209 }
210 
211 static __always_inline unsigned short stap(void)
212 {
213 	unsigned short cpu_address;
214 
215 	asm volatile("stap %0" : "=Q" (cpu_address));
216 	return cpu_address;
217 }
218 
219 #define cpu_relax() barrier()
220 
221 #define ECAG_CACHE_ATTRIBUTE	0
222 #define ECAG_CPU_ATTRIBUTE	1
223 
224 static inline unsigned long __ecag(unsigned int asi, unsigned char parm)
225 {
226 	unsigned long val;
227 
228 	asm volatile(".insn	rsy,0xeb000000004c,%0,0,0(%1)" /* ecag */
229 		     : "=d" (val) : "a" (asi << 8 | parm));
230 	return val;
231 }
232 
233 static inline void psw_set_key(unsigned int key)
234 {
235 	asm volatile("spka 0(%0)" : : "d" (key));
236 }
237 
238 /*
239  * Set PSW to specified value.
240  */
241 static inline void __load_psw(psw_t psw)
242 {
243 	asm volatile("lpswe %0" : : "Q" (psw) : "cc");
244 }
245 
246 /*
247  * Set PSW mask to specified value, while leaving the
248  * PSW addr pointing to the next instruction.
249  */
250 static __always_inline void __load_psw_mask(unsigned long mask)
251 {
252 	unsigned long addr;
253 	psw_t psw;
254 
255 	psw.mask = mask;
256 
257 	asm volatile(
258 		"	larl	%0,1f\n"
259 		"	stg	%0,%1\n"
260 		"	lpswe	%2\n"
261 		"1:"
262 		: "=&d" (addr), "=Q" (psw.addr) : "Q" (psw) : "memory", "cc");
263 }
264 
265 /*
266  * Extract current PSW mask
267  */
268 static inline unsigned long __extract_psw(void)
269 {
270 	unsigned int reg1, reg2;
271 
272 	asm volatile("epsw %0,%1" : "=d" (reg1), "=a" (reg2));
273 	return (((unsigned long) reg1) << 32) | ((unsigned long) reg2);
274 }
275 
276 static inline void local_mcck_enable(void)
277 {
278 	__load_psw_mask(__extract_psw() | PSW_MASK_MCHECK);
279 }
280 
281 static inline void local_mcck_disable(void)
282 {
283 	__load_psw_mask(__extract_psw() & ~PSW_MASK_MCHECK);
284 }
285 
286 /*
287  * Rewind PSW instruction address by specified number of bytes.
288  */
289 static inline unsigned long __rewind_psw(psw_t psw, unsigned long ilc)
290 {
291 	unsigned long mask;
292 
293 	mask = (psw.mask & PSW_MASK_EA) ? -1UL :
294 	       (psw.mask & PSW_MASK_BA) ? (1UL << 31) - 1 :
295 					  (1UL << 24) - 1;
296 	return (psw.addr - ilc) & mask;
297 }
298 
299 /*
300  * Function to drop a processor into disabled wait state
301  */
302 static __always_inline void __noreturn disabled_wait(void)
303 {
304 	psw_t psw;
305 
306 	psw.mask = PSW_MASK_BASE | PSW_MASK_WAIT | PSW_MASK_BA | PSW_MASK_EA;
307 	psw.addr = _THIS_IP_;
308 	__load_psw(psw);
309 	while (1);
310 }
311 
312 /*
313  * Basic Program Check Handler.
314  */
315 extern void s390_base_pgm_handler(void);
316 extern void (*s390_base_pgm_handler_fn)(void);
317 
318 #define ARCH_LOW_ADDRESS_LIMIT	0x7fffffffUL
319 
320 extern int memcpy_real(void *, void *, size_t);
321 extern void memcpy_absolute(void *, void *, size_t);
322 
323 #define mem_assign_absolute(dest, val) do {			\
324 	__typeof__(dest) __tmp = (val);				\
325 								\
326 	BUILD_BUG_ON(sizeof(__tmp) != sizeof(val));		\
327 	memcpy_absolute(&(dest), &__tmp, sizeof(__tmp));	\
328 } while (0)
329 
330 extern int s390_isolate_bp(void);
331 extern int s390_isolate_bp_guest(void);
332 
333 static __always_inline bool regs_irqs_disabled(struct pt_regs *regs)
334 {
335 	return arch_irqs_disabled_flags(regs->psw.mask);
336 }
337 
338 #endif /* __ASSEMBLY__ */
339 
340 #endif /* __ASM_S390_PROCESSOR_H */
341