xref: /openbmc/linux/arch/s390/include/asm/processor.h (revision 1edd0337)
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 __always_inline void set_cpu_flag(int flag)
48 {
49 	S390_lowcore.cpu_flags |= (1UL << flag);
50 }
51 
52 static __always_inline void clear_cpu_flag(int flag)
53 {
54 	S390_lowcore.cpu_flags &= ~(1UL << flag);
55 }
56 
57 static __always_inline bool test_cpu_flag(int flag)
58 {
59 	return S390_lowcore.cpu_flags & (1UL << flag);
60 }
61 
62 static __always_inline bool test_and_set_cpu_flag(int flag)
63 {
64 	if (test_cpu_flag(flag))
65 		return true;
66 	set_cpu_flag(flag);
67 	return false;
68 }
69 
70 static __always_inline bool test_and_clear_cpu_flag(int flag)
71 {
72 	if (!test_cpu_flag(flag))
73 		return false;
74 	clear_cpu_flag(flag);
75 	return true;
76 }
77 
78 /*
79  * Test CIF flag of another CPU. The caller needs to ensure that
80  * CPU hotplug can not happen, e.g. by disabling preemption.
81  */
82 static __always_inline bool test_cpu_flag_of(int flag, int cpu)
83 {
84 	struct lowcore *lc = lowcore_ptr[cpu];
85 
86 	return lc->cpu_flags & (1UL << flag);
87 }
88 
89 #define arch_needs_cpu() test_cpu_flag(CIF_NOHZ_DELAY)
90 
91 static inline void get_cpu_id(struct cpuid *ptr)
92 {
93 	asm volatile("stidp %0" : "=Q" (*ptr));
94 }
95 
96 void s390_adjust_jiffies(void);
97 void s390_update_cpu_mhz(void);
98 void cpu_detect_mhz_feature(void);
99 
100 extern const struct seq_operations cpuinfo_op;
101 extern void execve_tail(void);
102 extern void __bpon(void);
103 unsigned long vdso_size(void);
104 
105 /*
106  * User space process size: 2GB for 31 bit, 4TB or 8PT for 64 bit.
107  */
108 
109 #define TASK_SIZE		(test_thread_flag(TIF_31BIT) ? \
110 					_REGION3_SIZE : TASK_SIZE_MAX)
111 #define TASK_UNMAPPED_BASE	(test_thread_flag(TIF_31BIT) ? \
112 					(_REGION3_SIZE >> 1) : (_REGION2_SIZE >> 1))
113 #define TASK_SIZE_MAX		(-PAGE_SIZE)
114 
115 #define VDSO_BASE		(STACK_TOP + PAGE_SIZE)
116 #define VDSO_LIMIT		(test_thread_flag(TIF_31BIT) ? _REGION3_SIZE : _REGION2_SIZE)
117 #define STACK_TOP		(VDSO_LIMIT - vdso_size() - PAGE_SIZE)
118 #define STACK_TOP_MAX		(_REGION2_SIZE - vdso_size() - PAGE_SIZE)
119 
120 #define HAVE_ARCH_PICK_MMAP_LAYOUT
121 
122 /*
123  * Thread structure
124  */
125 struct thread_struct {
126 	unsigned int  acrs[NUM_ACRS];
127 	unsigned long ksp;			/* kernel stack pointer */
128 	unsigned long user_timer;		/* task cputime in user space */
129 	unsigned long guest_timer;		/* task cputime in kvm guest */
130 	unsigned long system_timer;		/* task cputime in kernel space */
131 	unsigned long hardirq_timer;		/* task cputime in hardirq context */
132 	unsigned long softirq_timer;		/* task cputime in softirq context */
133 	const sys_call_ptr_t *sys_call_table;	/* system call table address */
134 	unsigned long gmap_addr;		/* address of last gmap fault. */
135 	unsigned int gmap_write_flag;		/* gmap fault write indication */
136 	unsigned int gmap_int_code;		/* int code of last gmap fault */
137 	unsigned int gmap_pfault;		/* signal of a pending guest pfault */
138 
139 	/* Per-thread information related to debugging */
140 	struct per_regs per_user;		/* User specified PER registers */
141 	struct per_event per_event;		/* Cause of the last PER trap */
142 	unsigned long per_flags;		/* Flags to control debug behavior */
143 	unsigned int system_call;		/* system call number in signal */
144 	unsigned long last_break;		/* last breaking-event-address. */
145 	/* pfault_wait is used to block the process on a pfault event */
146 	unsigned long pfault_wait;
147 	struct list_head list;
148 	/* cpu runtime instrumentation */
149 	struct runtime_instr_cb *ri_cb;
150 	struct gs_cb *gs_cb;			/* Current guarded storage cb */
151 	struct gs_cb *gs_bc_cb;			/* Broadcast guarded storage cb */
152 	struct pgm_tdb trap_tdb;		/* Transaction abort diagnose block */
153 	/*
154 	 * Warning: 'fpu' is dynamically-sized. It *MUST* be at
155 	 * the end.
156 	 */
157 	struct fpu fpu;			/* FP and VX register save area */
158 };
159 
160 /* Flag to disable transactions. */
161 #define PER_FLAG_NO_TE			1UL
162 /* Flag to enable random transaction aborts. */
163 #define PER_FLAG_TE_ABORT_RAND		2UL
164 /* Flag to specify random transaction abort mode:
165  * - abort each transaction at a random instruction before TEND if set.
166  * - abort random transactions at a random instruction if cleared.
167  */
168 #define PER_FLAG_TE_ABORT_RAND_TEND	4UL
169 
170 typedef struct thread_struct thread_struct;
171 
172 #define ARCH_MIN_TASKALIGN	8
173 
174 #define INIT_THREAD {							\
175 	.ksp = sizeof(init_stack) + (unsigned long) &init_stack,	\
176 	.fpu.regs = (void *) init_task.thread.fpu.fprs,			\
177 	.last_break = 1,						\
178 }
179 
180 /*
181  * Do necessary setup to start up a new thread.
182  */
183 #define start_thread(regs, new_psw, new_stackp) do {			\
184 	regs->psw.mask	= PSW_USER_BITS | PSW_MASK_EA | PSW_MASK_BA;	\
185 	regs->psw.addr	= new_psw;					\
186 	regs->gprs[15]	= new_stackp;					\
187 	execve_tail();							\
188 } while (0)
189 
190 #define start_thread31(regs, new_psw, new_stackp) do {			\
191 	regs->psw.mask	= PSW_USER_BITS | PSW_MASK_BA;			\
192 	regs->psw.addr	= new_psw;					\
193 	regs->gprs[15]	= new_stackp;					\
194 	execve_tail();							\
195 } while (0)
196 
197 /* Forward declaration, a strange C thing */
198 struct task_struct;
199 struct mm_struct;
200 struct seq_file;
201 struct pt_regs;
202 
203 void show_registers(struct pt_regs *regs);
204 void show_cacheinfo(struct seq_file *m);
205 
206 /* Free guarded storage control block */
207 void guarded_storage_release(struct task_struct *tsk);
208 void gs_load_bc_cb(struct pt_regs *regs);
209 
210 unsigned long __get_wchan(struct task_struct *p);
211 #define task_pt_regs(tsk) ((struct pt_regs *) \
212         (task_stack_page(tsk) + THREAD_SIZE) - 1)
213 #define KSTK_EIP(tsk)	(task_pt_regs(tsk)->psw.addr)
214 #define KSTK_ESP(tsk)	(task_pt_regs(tsk)->gprs[15])
215 
216 /* Has task runtime instrumentation enabled ? */
217 #define is_ri_task(tsk) (!!(tsk)->thread.ri_cb)
218 
219 /* avoid using global register due to gcc bug in versions < 8.4 */
220 #define current_stack_pointer (__current_stack_pointer())
221 
222 static __always_inline unsigned long __current_stack_pointer(void)
223 {
224 	unsigned long sp;
225 
226 	asm volatile("lgr %0,15" : "=d" (sp));
227 	return sp;
228 }
229 
230 static __always_inline unsigned short stap(void)
231 {
232 	unsigned short cpu_address;
233 
234 	asm volatile("stap %0" : "=Q" (cpu_address));
235 	return cpu_address;
236 }
237 
238 #define cpu_relax() barrier()
239 
240 #define ECAG_CACHE_ATTRIBUTE	0
241 #define ECAG_CPU_ATTRIBUTE	1
242 
243 static inline unsigned long __ecag(unsigned int asi, unsigned char parm)
244 {
245 	unsigned long val;
246 
247 	asm volatile("ecag %0,0,0(%1)" : "=d" (val) : "a" (asi << 8 | parm));
248 	return val;
249 }
250 
251 static inline void psw_set_key(unsigned int key)
252 {
253 	asm volatile("spka 0(%0)" : : "d" (key));
254 }
255 
256 /*
257  * Set PSW to specified value.
258  */
259 static inline void __load_psw(psw_t psw)
260 {
261 	asm volatile("lpswe %0" : : "Q" (psw) : "cc");
262 }
263 
264 /*
265  * Set PSW mask to specified value, while leaving the
266  * PSW addr pointing to the next instruction.
267  */
268 static __always_inline void __load_psw_mask(unsigned long mask)
269 {
270 	unsigned long addr;
271 	psw_t psw;
272 
273 	psw.mask = mask;
274 
275 	asm volatile(
276 		"	larl	%0,1f\n"
277 		"	stg	%0,%1\n"
278 		"	lpswe	%2\n"
279 		"1:"
280 		: "=&d" (addr), "=Q" (psw.addr) : "Q" (psw) : "memory", "cc");
281 }
282 
283 /*
284  * Extract current PSW mask
285  */
286 static inline unsigned long __extract_psw(void)
287 {
288 	unsigned int reg1, reg2;
289 
290 	asm volatile("epsw %0,%1" : "=d" (reg1), "=a" (reg2));
291 	return (((unsigned long) reg1) << 32) | ((unsigned long) reg2);
292 }
293 
294 static inline void local_mcck_enable(void)
295 {
296 	__load_psw_mask(__extract_psw() | PSW_MASK_MCHECK);
297 }
298 
299 static inline void local_mcck_disable(void)
300 {
301 	__load_psw_mask(__extract_psw() & ~PSW_MASK_MCHECK);
302 }
303 
304 /*
305  * Rewind PSW instruction address by specified number of bytes.
306  */
307 static inline unsigned long __rewind_psw(psw_t psw, unsigned long ilc)
308 {
309 	unsigned long mask;
310 
311 	mask = (psw.mask & PSW_MASK_EA) ? -1UL :
312 	       (psw.mask & PSW_MASK_BA) ? (1UL << 31) - 1 :
313 					  (1UL << 24) - 1;
314 	return (psw.addr - ilc) & mask;
315 }
316 
317 /*
318  * Function to drop a processor into disabled wait state
319  */
320 static __always_inline void __noreturn disabled_wait(void)
321 {
322 	psw_t psw;
323 
324 	psw.mask = PSW_MASK_BASE | PSW_MASK_WAIT | PSW_MASK_BA | PSW_MASK_EA;
325 	psw.addr = _THIS_IP_;
326 	__load_psw(psw);
327 	while (1);
328 }
329 
330 #define ARCH_LOW_ADDRESS_LIMIT	0x7fffffffUL
331 
332 extern int s390_isolate_bp(void);
333 extern int s390_isolate_bp_guest(void);
334 
335 static __always_inline bool regs_irqs_disabled(struct pt_regs *regs)
336 {
337 	return arch_irqs_disabled_flags(regs->psw.mask);
338 }
339 
340 #endif /* __ASSEMBLY__ */
341 
342 #endif /* __ASM_S390_PROCESSOR_H */
343