xref: /openbmc/linux/arch/s390/include/asm/processor.h (revision 6abeae2a)
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 
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 static inline void get_cpu_id(struct cpuid *ptr)
70 {
71 	asm volatile("stidp %0" : "=Q" (*ptr));
72 }
73 
74 void s390_adjust_jiffies(void);
75 void s390_update_cpu_mhz(void);
76 void cpu_detect_mhz_feature(void);
77 
78 extern const struct seq_operations cpuinfo_op;
79 extern void execve_tail(void);
80 extern void __bpon(void);
81 
82 /*
83  * User space process size: 2GB for 31 bit, 4TB or 8PT for 64 bit.
84  */
85 
86 #define TASK_SIZE_OF(tsk)	(test_tsk_thread_flag(tsk, TIF_31BIT) ? \
87 					_REGION3_SIZE : TASK_SIZE_MAX)
88 #define TASK_UNMAPPED_BASE	(test_thread_flag(TIF_31BIT) ? \
89 					(_REGION3_SIZE >> 1) : (_REGION2_SIZE >> 1))
90 #define TASK_SIZE		TASK_SIZE_OF(current)
91 #define TASK_SIZE_MAX		(-PAGE_SIZE)
92 
93 #define STACK_TOP		(test_thread_flag(TIF_31BIT) ? \
94 					_REGION3_SIZE : _REGION2_SIZE)
95 #define STACK_TOP_MAX		_REGION2_SIZE
96 
97 #define HAVE_ARCH_PICK_MMAP_LAYOUT
98 
99 /*
100  * Thread structure
101  */
102 struct thread_struct {
103 	unsigned int  acrs[NUM_ACRS];
104         unsigned long ksp;              /* kernel stack pointer             */
105 	unsigned long user_timer;	/* task cputime in user space */
106 	unsigned long guest_timer;	/* task cputime in kvm guest */
107 	unsigned long system_timer;	/* task cputime in kernel space */
108 	unsigned long hardirq_timer;	/* task cputime in hardirq context */
109 	unsigned long softirq_timer;	/* task cputime in softirq context */
110 	unsigned long sys_call_table;	/* system call table address */
111 	unsigned long gmap_addr;	/* address of last gmap fault. */
112 	unsigned int gmap_write_flag;	/* gmap fault write indication */
113 	unsigned int gmap_int_code;	/* int code of last gmap fault */
114 	unsigned int gmap_pfault;	/* signal of a pending guest pfault */
115 	/* Per-thread information related to debugging */
116 	struct per_regs per_user;	/* User specified PER registers */
117 	struct per_event per_event;	/* Cause of the last PER trap */
118 	unsigned long per_flags;	/* Flags to control debug behavior */
119 	unsigned int system_call;	/* system call number in signal */
120 	unsigned long last_break;	/* last breaking-event-address. */
121         /* pfault_wait is used to block the process on a pfault event */
122 	unsigned long pfault_wait;
123 	struct list_head list;
124 	/* cpu runtime instrumentation */
125 	struct runtime_instr_cb *ri_cb;
126 	struct gs_cb *gs_cb;		/* Current guarded storage cb */
127 	struct gs_cb *gs_bc_cb;		/* Broadcast guarded storage cb */
128 	unsigned char trap_tdb[256];	/* Transaction abort diagnose block */
129 	/*
130 	 * Warning: 'fpu' is dynamically-sized. It *MUST* be at
131 	 * the end.
132 	 */
133 	struct fpu fpu;			/* FP and VX register save area */
134 };
135 
136 /* Flag to disable transactions. */
137 #define PER_FLAG_NO_TE			1UL
138 /* Flag to enable random transaction aborts. */
139 #define PER_FLAG_TE_ABORT_RAND		2UL
140 /* Flag to specify random transaction abort mode:
141  * - abort each transaction at a random instruction before TEND if set.
142  * - abort random transactions at a random instruction if cleared.
143  */
144 #define PER_FLAG_TE_ABORT_RAND_TEND	4UL
145 
146 typedef struct thread_struct thread_struct;
147 
148 #define ARCH_MIN_TASKALIGN	8
149 
150 #define INIT_THREAD {							\
151 	.ksp = sizeof(init_stack) + (unsigned long) &init_stack,	\
152 	.fpu.regs = (void *) init_task.thread.fpu.fprs,			\
153 	.last_break = 1,						\
154 }
155 
156 /*
157  * Do necessary setup to start up a new thread.
158  */
159 #define start_thread(regs, new_psw, new_stackp) do {			\
160 	regs->psw.mask	= PSW_USER_BITS | PSW_MASK_EA | PSW_MASK_BA;	\
161 	regs->psw.addr	= new_psw;					\
162 	regs->gprs[15]	= new_stackp;					\
163 	execve_tail();							\
164 } while (0)
165 
166 #define start_thread31(regs, new_psw, new_stackp) do {			\
167 	regs->psw.mask	= PSW_USER_BITS | PSW_MASK_BA;			\
168 	regs->psw.addr	= new_psw;					\
169 	regs->gprs[15]	= new_stackp;					\
170 	execve_tail();							\
171 } while (0)
172 
173 /* Forward declaration, a strange C thing */
174 struct task_struct;
175 struct mm_struct;
176 struct seq_file;
177 struct pt_regs;
178 
179 void show_registers(struct pt_regs *regs);
180 void show_cacheinfo(struct seq_file *m);
181 
182 /* Free all resources held by a thread. */
183 static inline void release_thread(struct task_struct *tsk) { }
184 
185 /* Free guarded storage control block */
186 void guarded_storage_release(struct task_struct *tsk);
187 
188 unsigned long get_wchan(struct task_struct *p);
189 #define task_pt_regs(tsk) ((struct pt_regs *) \
190         (task_stack_page(tsk) + THREAD_SIZE) - 1)
191 #define KSTK_EIP(tsk)	(task_pt_regs(tsk)->psw.addr)
192 #define KSTK_ESP(tsk)	(task_pt_regs(tsk)->gprs[15])
193 
194 /* Has task runtime instrumentation enabled ? */
195 #define is_ri_task(tsk) (!!(tsk)->thread.ri_cb)
196 
197 static __always_inline unsigned long current_stack_pointer(void)
198 {
199 	unsigned long sp;
200 
201 	asm volatile("la %0,0(15)" : "=a" (sp));
202 	return sp;
203 }
204 
205 static __no_kasan_or_inline unsigned short stap(void)
206 {
207 	unsigned short cpu_address;
208 
209 	asm volatile("stap %0" : "=Q" (cpu_address));
210 	return cpu_address;
211 }
212 
213 #define cpu_relax() barrier()
214 
215 #define ECAG_CACHE_ATTRIBUTE	0
216 #define ECAG_CPU_ATTRIBUTE	1
217 
218 static inline unsigned long __ecag(unsigned int asi, unsigned char parm)
219 {
220 	unsigned long val;
221 
222 	asm volatile(".insn	rsy,0xeb000000004c,%0,0,0(%1)" /* ecag */
223 		     : "=d" (val) : "a" (asi << 8 | parm));
224 	return val;
225 }
226 
227 static inline void psw_set_key(unsigned int key)
228 {
229 	asm volatile("spka 0(%0)" : : "d" (key));
230 }
231 
232 /*
233  * Set PSW to specified value.
234  */
235 static inline void __load_psw(psw_t psw)
236 {
237 	asm volatile("lpswe %0" : : "Q" (psw) : "cc");
238 }
239 
240 /*
241  * Set PSW mask to specified value, while leaving the
242  * PSW addr pointing to the next instruction.
243  */
244 static __no_kasan_or_inline void __load_psw_mask(unsigned long mask)
245 {
246 	unsigned long addr;
247 	psw_t psw;
248 
249 	psw.mask = mask;
250 
251 	asm volatile(
252 		"	larl	%0,1f\n"
253 		"	stg	%0,%1\n"
254 		"	lpswe	%2\n"
255 		"1:"
256 		: "=&d" (addr), "=Q" (psw.addr) : "Q" (psw) : "memory", "cc");
257 }
258 
259 /*
260  * Extract current PSW mask
261  */
262 static inline unsigned long __extract_psw(void)
263 {
264 	unsigned int reg1, reg2;
265 
266 	asm volatile("epsw %0,%1" : "=d" (reg1), "=a" (reg2));
267 	return (((unsigned long) reg1) << 32) | ((unsigned long) reg2);
268 }
269 
270 static inline void local_mcck_enable(void)
271 {
272 	__load_psw_mask(__extract_psw() | PSW_MASK_MCHECK);
273 }
274 
275 static inline void local_mcck_disable(void)
276 {
277 	__load_psw_mask(__extract_psw() & ~PSW_MASK_MCHECK);
278 }
279 
280 /*
281  * Rewind PSW instruction address by specified number of bytes.
282  */
283 static inline unsigned long __rewind_psw(psw_t psw, unsigned long ilc)
284 {
285 	unsigned long mask;
286 
287 	mask = (psw.mask & PSW_MASK_EA) ? -1UL :
288 	       (psw.mask & PSW_MASK_BA) ? (1UL << 31) - 1 :
289 					  (1UL << 24) - 1;
290 	return (psw.addr - ilc) & mask;
291 }
292 
293 /*
294  * Function to drop a processor into disabled wait state
295  */
296 static __always_inline void __noreturn disabled_wait(void)
297 {
298 	psw_t psw;
299 
300 	psw.mask = PSW_MASK_BASE | PSW_MASK_WAIT | PSW_MASK_BA | PSW_MASK_EA;
301 	psw.addr = _THIS_IP_;
302 	__load_psw(psw);
303 	while (1);
304 }
305 
306 /*
307  * Basic Program Check Handler.
308  */
309 extern void s390_base_pgm_handler(void);
310 extern void (*s390_base_pgm_handler_fn)(void);
311 
312 #define ARCH_LOW_ADDRESS_LIMIT	0x7fffffffUL
313 
314 extern int memcpy_real(void *, void *, size_t);
315 extern void memcpy_absolute(void *, void *, size_t);
316 
317 #define mem_assign_absolute(dest, val) do {			\
318 	__typeof__(dest) __tmp = (val);				\
319 								\
320 	BUILD_BUG_ON(sizeof(__tmp) != sizeof(val));		\
321 	memcpy_absolute(&(dest), &__tmp, sizeof(__tmp));	\
322 } while (0)
323 
324 extern int s390_isolate_bp(void);
325 extern int s390_isolate_bp_guest(void);
326 
327 #endif /* __ASSEMBLY__ */
328 
329 #endif /* __ASM_S390_PROCESSOR_H */
330