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 
set_cpu_flag(int flag)47 static inline void set_cpu_flag(int flag)
48 {
49 	S390_lowcore.cpu_flags |= (1UL << flag);
50 }
51 
clear_cpu_flag(int flag)52 static inline void clear_cpu_flag(int flag)
53 {
54 	S390_lowcore.cpu_flags &= ~(1UL << flag);
55 }
56 
test_cpu_flag(int flag)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  */
test_cpu_flag_of(int flag,int cpu)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 
get_cpu_id(struct cpuid * ptr)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 unsigned long vdso_size(void);
87 
88 /*
89  * User space process size: 2GB for 31 bit, 4TB or 8PT for 64 bit.
90  */
91 
92 #define TASK_SIZE		(test_thread_flag(TIF_31BIT) ? \
93 					_REGION3_SIZE : TASK_SIZE_MAX)
94 #define TASK_UNMAPPED_BASE	(test_thread_flag(TIF_31BIT) ? \
95 					(_REGION3_SIZE >> 1) : (_REGION2_SIZE >> 1))
96 #define TASK_SIZE_MAX		(-PAGE_SIZE)
97 
98 #define VDSO_BASE		(STACK_TOP + PAGE_SIZE)
99 #define VDSO_LIMIT		(test_thread_flag(TIF_31BIT) ? _REGION3_SIZE : _REGION2_SIZE)
100 #define STACK_TOP		(VDSO_LIMIT - vdso_size() - PAGE_SIZE)
101 #define STACK_TOP_MAX		(_REGION2_SIZE - vdso_size() - PAGE_SIZE)
102 
103 #define HAVE_ARCH_PICK_MMAP_LAYOUT
104 
105 /*
106  * Thread structure
107  */
108 struct thread_struct {
109 	unsigned int  acrs[NUM_ACRS];
110 	unsigned long ksp;			/* kernel stack pointer */
111 	unsigned long user_timer;		/* task cputime in user space */
112 	unsigned long guest_timer;		/* task cputime in kvm guest */
113 	unsigned long system_timer;		/* task cputime in kernel space */
114 	unsigned long hardirq_timer;		/* task cputime in hardirq context */
115 	unsigned long softirq_timer;		/* task cputime in softirq context */
116 	const sys_call_ptr_t *sys_call_table;	/* system call table address */
117 	unsigned long gmap_addr;		/* address of last gmap fault. */
118 	unsigned int gmap_write_flag;		/* gmap fault write indication */
119 	unsigned int gmap_int_code;		/* int code of last gmap fault */
120 	unsigned int gmap_pfault;		/* signal of a pending guest pfault */
121 
122 	/* Per-thread information related to debugging */
123 	struct per_regs per_user;		/* User specified PER registers */
124 	struct per_event per_event;		/* Cause of the last PER trap */
125 	unsigned long per_flags;		/* Flags to control debug behavior */
126 	unsigned int system_call;		/* system call number in signal */
127 	unsigned long last_break;		/* last breaking-event-address. */
128 	/* pfault_wait is used to block the process on a pfault event */
129 	unsigned long pfault_wait;
130 	struct list_head list;
131 	/* cpu runtime instrumentation */
132 	struct runtime_instr_cb *ri_cb;
133 	struct gs_cb *gs_cb;			/* Current guarded storage cb */
134 	struct gs_cb *gs_bc_cb;			/* Broadcast guarded storage cb */
135 	struct pgm_tdb trap_tdb;		/* Transaction abort diagnose block */
136 	/*
137 	 * Warning: 'fpu' is dynamically-sized. It *MUST* be at
138 	 * the end.
139 	 */
140 	struct fpu fpu;			/* FP and VX register save area */
141 };
142 
143 /* Flag to disable transactions. */
144 #define PER_FLAG_NO_TE			1UL
145 /* Flag to enable random transaction aborts. */
146 #define PER_FLAG_TE_ABORT_RAND		2UL
147 /* Flag to specify random transaction abort mode:
148  * - abort each transaction at a random instruction before TEND if set.
149  * - abort random transactions at a random instruction if cleared.
150  */
151 #define PER_FLAG_TE_ABORT_RAND_TEND	4UL
152 
153 typedef struct thread_struct thread_struct;
154 
155 #define ARCH_MIN_TASKALIGN	8
156 
157 #define INIT_THREAD {							\
158 	.ksp = sizeof(init_stack) + (unsigned long) &init_stack,	\
159 	.fpu.regs = (void *) init_task.thread.fpu.fprs,			\
160 	.last_break = 1,						\
161 }
162 
163 /*
164  * Do necessary setup to start up a new thread.
165  */
166 #define start_thread(regs, new_psw, new_stackp) do {			\
167 	regs->psw.mask	= PSW_USER_BITS | PSW_MASK_EA | PSW_MASK_BA;	\
168 	regs->psw.addr	= new_psw;					\
169 	regs->gprs[15]	= new_stackp;					\
170 	execve_tail();							\
171 } while (0)
172 
173 #define start_thread31(regs, new_psw, new_stackp) do {			\
174 	regs->psw.mask	= PSW_USER_BITS | PSW_MASK_BA;			\
175 	regs->psw.addr	= new_psw;					\
176 	regs->gprs[15]	= new_stackp;					\
177 	execve_tail();							\
178 } while (0)
179 
180 /* Forward declaration, a strange C thing */
181 struct task_struct;
182 struct mm_struct;
183 struct seq_file;
184 struct pt_regs;
185 
186 void show_registers(struct pt_regs *regs);
187 void show_cacheinfo(struct seq_file *m);
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 /* avoid using global register due to gcc bug in versions < 8.4 */
203 #define current_stack_pointer (__current_stack_pointer())
204 
__current_stack_pointer(void)205 static __always_inline unsigned long __current_stack_pointer(void)
206 {
207 	unsigned long sp;
208 
209 	asm volatile("lgr %0,15" : "=d" (sp));
210 	return sp;
211 }
212 
stap(void)213 static __always_inline unsigned short stap(void)
214 {
215 	unsigned short cpu_address;
216 
217 	asm volatile("stap %0" : "=Q" (cpu_address));
218 	return cpu_address;
219 }
220 
221 #define cpu_relax() barrier()
222 
223 #define ECAG_CACHE_ATTRIBUTE	0
224 #define ECAG_CPU_ATTRIBUTE	1
225 
__ecag(unsigned int asi,unsigned char parm)226 static inline unsigned long __ecag(unsigned int asi, unsigned char parm)
227 {
228 	unsigned long val;
229 
230 	asm volatile("ecag %0,0,0(%1)" : "=d" (val) : "a" (asi << 8 | parm));
231 	return val;
232 }
233 
psw_set_key(unsigned int key)234 static inline void psw_set_key(unsigned int key)
235 {
236 	asm volatile("spka 0(%0)" : : "d" (key));
237 }
238 
239 /*
240  * Set PSW to specified value.
241  */
__load_psw(psw_t psw)242 static inline void __load_psw(psw_t psw)
243 {
244 	asm volatile("lpswe %0" : : "Q" (psw) : "cc");
245 }
246 
247 /*
248  * Set PSW mask to specified value, while leaving the
249  * PSW addr pointing to the next instruction.
250  */
__load_psw_mask(unsigned long mask)251 static __always_inline void __load_psw_mask(unsigned long mask)
252 {
253 	unsigned long addr;
254 	psw_t psw;
255 
256 	psw.mask = mask;
257 
258 	asm volatile(
259 		"	larl	%0,1f\n"
260 		"	stg	%0,%1\n"
261 		"	lpswe	%2\n"
262 		"1:"
263 		: "=&d" (addr), "=Q" (psw.addr) : "Q" (psw) : "memory", "cc");
264 }
265 
266 /*
267  * Extract current PSW mask
268  */
__extract_psw(void)269 static inline unsigned long __extract_psw(void)
270 {
271 	unsigned int reg1, reg2;
272 
273 	asm volatile("epsw %0,%1" : "=d" (reg1), "=a" (reg2));
274 	return (((unsigned long) reg1) << 32) | ((unsigned long) reg2);
275 }
276 
local_mcck_enable(void)277 static inline void local_mcck_enable(void)
278 {
279 	__load_psw_mask(__extract_psw() | PSW_MASK_MCHECK);
280 }
281 
local_mcck_disable(void)282 static inline void local_mcck_disable(void)
283 {
284 	__load_psw_mask(__extract_psw() & ~PSW_MASK_MCHECK);
285 }
286 
287 /*
288  * Rewind PSW instruction address by specified number of bytes.
289  */
__rewind_psw(psw_t psw,unsigned long ilc)290 static inline unsigned long __rewind_psw(psw_t psw, unsigned long ilc)
291 {
292 	unsigned long mask;
293 
294 	mask = (psw.mask & PSW_MASK_EA) ? -1UL :
295 	       (psw.mask & PSW_MASK_BA) ? (1UL << 31) - 1 :
296 					  (1UL << 24) - 1;
297 	return (psw.addr - ilc) & mask;
298 }
299 
300 /*
301  * Function to drop a processor into disabled wait state
302  */
disabled_wait(void)303 static __always_inline void __noreturn disabled_wait(void)
304 {
305 	psw_t psw;
306 
307 	psw.mask = PSW_MASK_BASE | PSW_MASK_WAIT | PSW_MASK_BA | PSW_MASK_EA;
308 	psw.addr = _THIS_IP_;
309 	__load_psw(psw);
310 	while (1);
311 }
312 
313 #define ARCH_LOW_ADDRESS_LIMIT	0x7fffffffUL
314 
315 extern int s390_isolate_bp(void);
316 extern int s390_isolate_bp_guest(void);
317 
regs_irqs_disabled(struct pt_regs * regs)318 static __always_inline bool regs_irqs_disabled(struct pt_regs *regs)
319 {
320 	return arch_irqs_disabled_flags(regs->psw.mask);
321 }
322 
323 #endif /* __ASSEMBLY__ */
324 
325 #endif /* __ASM_S390_PROCESSOR_H */
326