xref: /openbmc/linux/arch/s390/include/asm/processor.h (revision 7ce05074)
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 #ifndef __ASSEMBLY__
30 
31 #include <linux/cpumask.h>
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 #include <asm/irqflags.h>
42 
43 typedef long (*sys_call_ptr_t)(struct pt_regs *regs);
44 
45 static inline void set_cpu_flag(int flag)
46 {
47 	S390_lowcore.cpu_flags |= (1UL << flag);
48 }
49 
50 static inline void clear_cpu_flag(int flag)
51 {
52 	S390_lowcore.cpu_flags &= ~(1UL << flag);
53 }
54 
55 static inline int test_cpu_flag(int flag)
56 {
57 	return !!(S390_lowcore.cpu_flags & (1UL << flag));
58 }
59 
60 /*
61  * Test CIF flag of another CPU. The caller needs to ensure that
62  * CPU hotplug can not happen, e.g. by disabling preemption.
63  */
64 static inline int test_cpu_flag_of(int flag, int cpu)
65 {
66 	struct lowcore *lc = lowcore_ptr[cpu];
67 	return !!(lc->cpu_flags & (1UL << flag));
68 }
69 
70 #define arch_needs_cpu() test_cpu_flag(CIF_NOHZ_DELAY)
71 
72 static inline void get_cpu_id(struct cpuid *ptr)
73 {
74 	asm volatile("stidp %0" : "=Q" (*ptr));
75 }
76 
77 void s390_adjust_jiffies(void);
78 void s390_update_cpu_mhz(void);
79 void cpu_detect_mhz_feature(void);
80 
81 extern const struct seq_operations cpuinfo_op;
82 extern void execve_tail(void);
83 extern void __bpon(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)	(test_tsk_thread_flag(tsk, TIF_31BIT) ? \
90 					_REGION3_SIZE : TASK_SIZE_MAX)
91 #define TASK_UNMAPPED_BASE	(test_thread_flag(TIF_31BIT) ? \
92 					(_REGION3_SIZE >> 1) : (_REGION2_SIZE >> 1))
93 #define TASK_SIZE		TASK_SIZE_OF(current)
94 #define TASK_SIZE_MAX		(-PAGE_SIZE)
95 
96 #define STACK_TOP		(test_thread_flag(TIF_31BIT) ? \
97 					_REGION3_SIZE : _REGION2_SIZE)
98 #define STACK_TOP_MAX		_REGION2_SIZE
99 
100 #define HAVE_ARCH_PICK_MMAP_LAYOUT
101 
102 /*
103  * Thread structure
104  */
105 struct thread_struct {
106 	unsigned int  acrs[NUM_ACRS];
107 	unsigned long ksp;			/* kernel stack pointer */
108 	unsigned long user_timer;		/* task cputime in user space */
109 	unsigned long guest_timer;		/* task cputime in kvm guest */
110 	unsigned long system_timer;		/* task cputime in kernel space */
111 	unsigned long hardirq_timer;		/* task cputime in hardirq context */
112 	unsigned long softirq_timer;		/* task cputime in softirq context */
113 	const sys_call_ptr_t *sys_call_table;	/* system call table address */
114 	unsigned long gmap_addr;		/* address of last gmap fault. */
115 	unsigned int gmap_write_flag;		/* gmap fault write indication */
116 	unsigned int gmap_int_code;		/* int code of last gmap fault */
117 	unsigned int gmap_pfault;		/* signal of a pending guest pfault */
118 
119 	/* Per-thread information related to debugging */
120 	struct per_regs per_user;		/* User specified PER registers */
121 	struct per_event per_event;		/* Cause of the last PER trap */
122 	unsigned long per_flags;		/* Flags to control debug behavior */
123 	unsigned int system_call;		/* system call number in signal */
124 	unsigned long last_break;		/* last breaking-event-address. */
125 	/* pfault_wait is used to block the process on a pfault event */
126 	unsigned long pfault_wait;
127 	struct list_head list;
128 	/* cpu runtime instrumentation */
129 	struct runtime_instr_cb *ri_cb;
130 	struct gs_cb *gs_cb;			/* Current guarded storage cb */
131 	struct gs_cb *gs_bc_cb;			/* Broadcast guarded storage cb */
132 	struct pgm_tdb trap_tdb;		/* Transaction abort diagnose block */
133 	/*
134 	 * Warning: 'fpu' is dynamically-sized. It *MUST* be at
135 	 * the end.
136 	 */
137 	struct fpu fpu;			/* FP and VX register save area */
138 };
139 
140 /* Flag to disable transactions. */
141 #define PER_FLAG_NO_TE			1UL
142 /* Flag to enable random transaction aborts. */
143 #define PER_FLAG_TE_ABORT_RAND		2UL
144 /* Flag to specify random transaction abort mode:
145  * - abort each transaction at a random instruction before TEND if set.
146  * - abort random transactions at a random instruction if cleared.
147  */
148 #define PER_FLAG_TE_ABORT_RAND_TEND	4UL
149 
150 typedef struct thread_struct thread_struct;
151 
152 #define ARCH_MIN_TASKALIGN	8
153 
154 #define INIT_THREAD {							\
155 	.ksp = sizeof(init_stack) + (unsigned long) &init_stack,	\
156 	.fpu.regs = (void *) init_task.thread.fpu.fprs,			\
157 	.last_break = 1,						\
158 }
159 
160 /*
161  * Do necessary setup to start up a new thread.
162  */
163 #define start_thread(regs, new_psw, new_stackp) do {			\
164 	regs->psw.mask	= PSW_USER_BITS | PSW_MASK_EA | PSW_MASK_BA;	\
165 	regs->psw.addr	= new_psw;					\
166 	regs->gprs[15]	= new_stackp;					\
167 	execve_tail();							\
168 } while (0)
169 
170 #define start_thread31(regs, new_psw, new_stackp) do {			\
171 	regs->psw.mask	= PSW_USER_BITS | PSW_MASK_BA;			\
172 	regs->psw.addr	= new_psw;					\
173 	regs->gprs[15]	= new_stackp;					\
174 	execve_tail();							\
175 } while (0)
176 
177 /* Forward declaration, a strange C thing */
178 struct task_struct;
179 struct mm_struct;
180 struct seq_file;
181 struct pt_regs;
182 
183 void show_registers(struct pt_regs *regs);
184 void show_cacheinfo(struct seq_file *m);
185 
186 /* Free all resources held by a thread. */
187 static inline void release_thread(struct task_struct *tsk) { }
188 
189 /* Free guarded storage control block */
190 void guarded_storage_release(struct task_struct *tsk);
191 void gs_load_bc_cb(struct pt_regs *regs);
192 
193 unsigned long get_wchan(struct task_struct *p);
194 #define task_pt_regs(tsk) ((struct pt_regs *) \
195         (task_stack_page(tsk) + THREAD_SIZE) - 1)
196 #define KSTK_EIP(tsk)	(task_pt_regs(tsk)->psw.addr)
197 #define KSTK_ESP(tsk)	(task_pt_regs(tsk)->gprs[15])
198 
199 /* Has task runtime instrumentation enabled ? */
200 #define is_ri_task(tsk) (!!(tsk)->thread.ri_cb)
201 
202 static __always_inline unsigned long current_stack_pointer(void)
203 {
204 	unsigned long sp;
205 
206 	asm volatile("la %0,0(15)" : "=a" (sp));
207 	return sp;
208 }
209 
210 static __always_inline unsigned short stap(void)
211 {
212 	unsigned short cpu_address;
213 
214 	asm volatile("stap %0" : "=Q" (cpu_address));
215 	return cpu_address;
216 }
217 
218 #define cpu_relax() barrier()
219 
220 #define ECAG_CACHE_ATTRIBUTE	0
221 #define ECAG_CPU_ATTRIBUTE	1
222 
223 static inline unsigned long __ecag(unsigned int asi, unsigned char parm)
224 {
225 	unsigned long val;
226 
227 	asm volatile(".insn	rsy,0xeb000000004c,%0,0,0(%1)" /* ecag */
228 		     : "=d" (val) : "a" (asi << 8 | parm));
229 	return val;
230 }
231 
232 static inline void psw_set_key(unsigned int key)
233 {
234 	asm volatile("spka 0(%0)" : : "d" (key));
235 }
236 
237 /*
238  * Set PSW to specified value.
239  */
240 static inline void __load_psw(psw_t psw)
241 {
242 	asm volatile("lpswe %0" : : "Q" (psw) : "cc");
243 }
244 
245 /*
246  * Set PSW mask to specified value, while leaving the
247  * PSW addr pointing to the next instruction.
248  */
249 static __always_inline void __load_psw_mask(unsigned long mask)
250 {
251 	unsigned long addr;
252 	psw_t psw;
253 
254 	psw.mask = mask;
255 
256 	asm volatile(
257 		"	larl	%0,1f\n"
258 		"	stg	%0,%1\n"
259 		"	lpswe	%2\n"
260 		"1:"
261 		: "=&d" (addr), "=Q" (psw.addr) : "Q" (psw) : "memory", "cc");
262 }
263 
264 /*
265  * Extract current PSW mask
266  */
267 static inline unsigned long __extract_psw(void)
268 {
269 	unsigned int reg1, reg2;
270 
271 	asm volatile("epsw %0,%1" : "=d" (reg1), "=a" (reg2));
272 	return (((unsigned long) reg1) << 32) | ((unsigned long) reg2);
273 }
274 
275 static inline void local_mcck_enable(void)
276 {
277 	__load_psw_mask(__extract_psw() | PSW_MASK_MCHECK);
278 }
279 
280 static inline void local_mcck_disable(void)
281 {
282 	__load_psw_mask(__extract_psw() & ~PSW_MASK_MCHECK);
283 }
284 
285 /*
286  * Rewind PSW instruction address by specified number of bytes.
287  */
288 static inline unsigned long __rewind_psw(psw_t psw, unsigned long ilc)
289 {
290 	unsigned long mask;
291 
292 	mask = (psw.mask & PSW_MASK_EA) ? -1UL :
293 	       (psw.mask & PSW_MASK_BA) ? (1UL << 31) - 1 :
294 					  (1UL << 24) - 1;
295 	return (psw.addr - ilc) & mask;
296 }
297 
298 /*
299  * Function to drop a processor into disabled wait state
300  */
301 static __always_inline void __noreturn disabled_wait(void)
302 {
303 	psw_t psw;
304 
305 	psw.mask = PSW_MASK_BASE | PSW_MASK_WAIT | PSW_MASK_BA | PSW_MASK_EA;
306 	psw.addr = _THIS_IP_;
307 	__load_psw(psw);
308 	while (1);
309 }
310 
311 /*
312  * Basic Program Check Handler.
313  */
314 extern void s390_base_pgm_handler(void);
315 extern void (*s390_base_pgm_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) do {			\
323 	__typeof__(dest) __tmp = (val);				\
324 								\
325 	BUILD_BUG_ON(sizeof(__tmp) != sizeof(val));		\
326 	memcpy_absolute(&(dest), &__tmp, sizeof(__tmp));	\
327 } while (0)
328 
329 extern int s390_isolate_bp(void);
330 extern int s390_isolate_bp_guest(void);
331 
332 static __always_inline bool regs_irqs_disabled(struct pt_regs *regs)
333 {
334 	return arch_irqs_disabled_flags(regs->psw.mask);
335 }
336 
337 #endif /* __ASSEMBLY__ */
338 
339 #endif /* __ASM_S390_PROCESSOR_H */
340