xref: /openbmc/linux/arch/s390/include/asm/processor.h (revision 22ca1e77)
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 unsigned long vdso_size(void);
103 
104 /*
105  * User space process size: 2GB for 31 bit, 4TB or 8PT for 64 bit.
106  */
107 
108 #define TASK_SIZE		(test_thread_flag(TIF_31BIT) ? \
109 					_REGION3_SIZE : TASK_SIZE_MAX)
110 #define TASK_UNMAPPED_BASE	(test_thread_flag(TIF_31BIT) ? \
111 					(_REGION3_SIZE >> 1) : (_REGION2_SIZE >> 1))
112 #define TASK_SIZE_MAX		(-PAGE_SIZE)
113 
114 #define VDSO_BASE		(STACK_TOP + PAGE_SIZE)
115 #define VDSO_LIMIT		(test_thread_flag(TIF_31BIT) ? _REGION3_SIZE : _REGION2_SIZE)
116 #define STACK_TOP		(VDSO_LIMIT - vdso_size() - PAGE_SIZE)
117 #define STACK_TOP_MAX		(_REGION2_SIZE - vdso_size() - PAGE_SIZE)
118 
119 #define HAVE_ARCH_PICK_MMAP_LAYOUT
120 
121 /*
122  * Thread structure
123  */
124 struct thread_struct {
125 	unsigned int  acrs[NUM_ACRS];
126 	unsigned long ksp;			/* kernel stack pointer */
127 	unsigned long user_timer;		/* task cputime in user space */
128 	unsigned long guest_timer;		/* task cputime in kvm guest */
129 	unsigned long system_timer;		/* task cputime in kernel space */
130 	unsigned long hardirq_timer;		/* task cputime in hardirq context */
131 	unsigned long softirq_timer;		/* task cputime in softirq context */
132 	const sys_call_ptr_t *sys_call_table;	/* system call table address */
133 	unsigned long gmap_addr;		/* address of last gmap fault. */
134 	unsigned int gmap_write_flag;		/* gmap fault write indication */
135 	unsigned int gmap_int_code;		/* int code of last gmap fault */
136 	unsigned int gmap_pfault;		/* signal of a pending guest pfault */
137 
138 	/* Per-thread information related to debugging */
139 	struct per_regs per_user;		/* User specified PER registers */
140 	struct per_event per_event;		/* Cause of the last PER trap */
141 	unsigned long per_flags;		/* Flags to control debug behavior */
142 	unsigned int system_call;		/* system call number in signal */
143 	unsigned long last_break;		/* last breaking-event-address. */
144 	/* pfault_wait is used to block the process on a pfault event */
145 	unsigned long pfault_wait;
146 	struct list_head list;
147 	/* cpu runtime instrumentation */
148 	struct runtime_instr_cb *ri_cb;
149 	struct gs_cb *gs_cb;			/* Current guarded storage cb */
150 	struct gs_cb *gs_bc_cb;			/* Broadcast guarded storage cb */
151 	struct pgm_tdb trap_tdb;		/* Transaction abort diagnose block */
152 	/*
153 	 * Warning: 'fpu' is dynamically-sized. It *MUST* be at
154 	 * the end.
155 	 */
156 	struct fpu fpu;			/* FP and VX register save area */
157 };
158 
159 /* Flag to disable transactions. */
160 #define PER_FLAG_NO_TE			1UL
161 /* Flag to enable random transaction aborts. */
162 #define PER_FLAG_TE_ABORT_RAND		2UL
163 /* Flag to specify random transaction abort mode:
164  * - abort each transaction at a random instruction before TEND if set.
165  * - abort random transactions at a random instruction if cleared.
166  */
167 #define PER_FLAG_TE_ABORT_RAND_TEND	4UL
168 
169 typedef struct thread_struct thread_struct;
170 
171 #define ARCH_MIN_TASKALIGN	8
172 
173 #define INIT_THREAD {							\
174 	.ksp = sizeof(init_stack) + (unsigned long) &init_stack,	\
175 	.fpu.regs = (void *) init_task.thread.fpu.fprs,			\
176 	.last_break = 1,						\
177 }
178 
179 /*
180  * Do necessary setup to start up a new thread.
181  */
182 #define start_thread(regs, new_psw, new_stackp) do {			\
183 	regs->psw.mask	= PSW_USER_BITS | PSW_MASK_EA | PSW_MASK_BA;	\
184 	regs->psw.addr	= new_psw;					\
185 	regs->gprs[15]	= new_stackp;					\
186 	execve_tail();							\
187 } while (0)
188 
189 #define start_thread31(regs, new_psw, new_stackp) do {			\
190 	regs->psw.mask	= PSW_USER_BITS | PSW_MASK_BA;			\
191 	regs->psw.addr	= new_psw;					\
192 	regs->gprs[15]	= new_stackp;					\
193 	execve_tail();							\
194 } while (0)
195 
196 /* Forward declaration, a strange C thing */
197 struct task_struct;
198 struct mm_struct;
199 struct seq_file;
200 struct pt_regs;
201 
202 void show_registers(struct pt_regs *regs);
203 void show_cacheinfo(struct seq_file *m);
204 
205 /* Free guarded storage control block */
206 void guarded_storage_release(struct task_struct *tsk);
207 void gs_load_bc_cb(struct pt_regs *regs);
208 
209 unsigned long __get_wchan(struct task_struct *p);
210 #define task_pt_regs(tsk) ((struct pt_regs *) \
211         (task_stack_page(tsk) + THREAD_SIZE) - 1)
212 #define KSTK_EIP(tsk)	(task_pt_regs(tsk)->psw.addr)
213 #define KSTK_ESP(tsk)	(task_pt_regs(tsk)->gprs[15])
214 
215 /* Has task runtime instrumentation enabled ? */
216 #define is_ri_task(tsk) (!!(tsk)->thread.ri_cb)
217 
218 /* avoid using global register due to gcc bug in versions < 8.4 */
219 #define current_stack_pointer (__current_stack_pointer())
220 
221 static __always_inline unsigned long __current_stack_pointer(void)
222 {
223 	unsigned long sp;
224 
225 	asm volatile("lgr %0,15" : "=d" (sp));
226 	return sp;
227 }
228 
229 static __always_inline bool on_thread_stack(void)
230 {
231 	unsigned long ksp = S390_lowcore.kernel_stack;
232 
233 	return !((ksp ^ current_stack_pointer) & ~(THREAD_SIZE - 1));
234 }
235 
236 static __always_inline unsigned short stap(void)
237 {
238 	unsigned short cpu_address;
239 
240 	asm volatile("stap %0" : "=Q" (cpu_address));
241 	return cpu_address;
242 }
243 
244 #define cpu_relax() barrier()
245 
246 #define ECAG_CACHE_ATTRIBUTE	0
247 #define ECAG_CPU_ATTRIBUTE	1
248 
249 static inline unsigned long __ecag(unsigned int asi, unsigned char parm)
250 {
251 	unsigned long val;
252 
253 	asm volatile("ecag %0,0,0(%1)" : "=d" (val) : "a" (asi << 8 | parm));
254 	return val;
255 }
256 
257 static inline void psw_set_key(unsigned int key)
258 {
259 	asm volatile("spka 0(%0)" : : "d" (key));
260 }
261 
262 /*
263  * Set PSW to specified value.
264  */
265 static inline void __load_psw(psw_t psw)
266 {
267 	asm volatile("lpswe %0" : : "Q" (psw) : "cc");
268 }
269 
270 /*
271  * Set PSW mask to specified value, while leaving the
272  * PSW addr pointing to the next instruction.
273  */
274 static __always_inline void __load_psw_mask(unsigned long mask)
275 {
276 	unsigned long addr;
277 	psw_t psw;
278 
279 	psw.mask = mask;
280 
281 	asm volatile(
282 		"	larl	%0,1f\n"
283 		"	stg	%0,%1\n"
284 		"	lpswe	%2\n"
285 		"1:"
286 		: "=&d" (addr), "=Q" (psw.addr) : "Q" (psw) : "memory", "cc");
287 }
288 
289 /*
290  * Extract current PSW mask
291  */
292 static inline unsigned long __extract_psw(void)
293 {
294 	unsigned int reg1, reg2;
295 
296 	asm volatile("epsw %0,%1" : "=d" (reg1), "=a" (reg2));
297 	return (((unsigned long) reg1) << 32) | ((unsigned long) reg2);
298 }
299 
300 static inline void local_mcck_enable(void)
301 {
302 	__load_psw_mask(__extract_psw() | PSW_MASK_MCHECK);
303 }
304 
305 static inline void local_mcck_disable(void)
306 {
307 	__load_psw_mask(__extract_psw() & ~PSW_MASK_MCHECK);
308 }
309 
310 /*
311  * Rewind PSW instruction address by specified number of bytes.
312  */
313 static inline unsigned long __rewind_psw(psw_t psw, unsigned long ilc)
314 {
315 	unsigned long mask;
316 
317 	mask = (psw.mask & PSW_MASK_EA) ? -1UL :
318 	       (psw.mask & PSW_MASK_BA) ? (1UL << 31) - 1 :
319 					  (1UL << 24) - 1;
320 	return (psw.addr - ilc) & mask;
321 }
322 
323 /*
324  * Function to drop a processor into disabled wait state
325  */
326 static __always_inline void __noreturn disabled_wait(void)
327 {
328 	psw_t psw;
329 
330 	psw.mask = PSW_MASK_BASE | PSW_MASK_WAIT | PSW_MASK_BA | PSW_MASK_EA;
331 	psw.addr = _THIS_IP_;
332 	__load_psw(psw);
333 	while (1);
334 }
335 
336 #define ARCH_LOW_ADDRESS_LIMIT	0x7fffffffUL
337 
338 static __always_inline bool regs_irqs_disabled(struct pt_regs *regs)
339 {
340 	return arch_irqs_disabled_flags(regs->psw.mask);
341 }
342 
343 #endif /* __ASSEMBLY__ */
344 
345 #endif /* __ASM_S390_PROCESSOR_H */
346