xref: /openbmc/linux/arch/sparc/kernel/kstack.h (revision e2c75e76)
1 /* SPDX-License-Identifier: GPL-2.0 */
2 #ifndef _KSTACK_H
3 #define _KSTACK_H
4 
5 #include <linux/thread_info.h>
6 #include <linux/sched.h>
7 #include <asm/ptrace.h>
8 #include <asm/irq.h>
9 
10 /* SP must be STACK_BIAS adjusted already.  */
11 static inline bool kstack_valid(struct thread_info *tp, unsigned long sp)
12 {
13 	unsigned long base = (unsigned long) tp;
14 
15 	/* Stack pointer must be 16-byte aligned.  */
16 	if (sp & (16UL - 1))
17 		return false;
18 
19 	if (sp >= (base + sizeof(struct thread_info)) &&
20 	    sp <= (base + THREAD_SIZE - sizeof(struct sparc_stackf)))
21 		return true;
22 
23 	if (hardirq_stack[tp->cpu]) {
24 		base = (unsigned long) hardirq_stack[tp->cpu];
25 		if (sp >= base &&
26 		    sp <= (base + THREAD_SIZE - sizeof(struct sparc_stackf)))
27 			return true;
28 		base = (unsigned long) softirq_stack[tp->cpu];
29 		if (sp >= base &&
30 		    sp <= (base + THREAD_SIZE - sizeof(struct sparc_stackf)))
31 			return true;
32 	}
33 	return false;
34 }
35 
36 /* Does "regs" point to a valid pt_regs trap frame?  */
37 static inline bool kstack_is_trap_frame(struct thread_info *tp, struct pt_regs *regs)
38 {
39 	unsigned long base = (unsigned long) tp;
40 	unsigned long addr = (unsigned long) regs;
41 
42 	if (addr >= base &&
43 	    addr <= (base + THREAD_SIZE - sizeof(*regs)))
44 		goto check_magic;
45 
46 	if (hardirq_stack[tp->cpu]) {
47 		base = (unsigned long) hardirq_stack[tp->cpu];
48 		if (addr >= base &&
49 		    addr <= (base + THREAD_SIZE - sizeof(*regs)))
50 			goto check_magic;
51 		base = (unsigned long) softirq_stack[tp->cpu];
52 		if (addr >= base &&
53 		    addr <= (base + THREAD_SIZE - sizeof(*regs)))
54 			goto check_magic;
55 	}
56 	return false;
57 
58 check_magic:
59 	if ((regs->magic & ~0x1ff) == PT_REGS_MAGIC)
60 		return true;
61 	return false;
62 
63 }
64 
65 static inline __attribute__((always_inline)) void *set_hardirq_stack(void)
66 {
67 	void *orig_sp, *sp = hardirq_stack[smp_processor_id()];
68 
69 	__asm__ __volatile__("mov %%sp, %0" : "=r" (orig_sp));
70 	if (orig_sp < sp ||
71 	    orig_sp > (sp + THREAD_SIZE)) {
72 		sp += THREAD_SIZE - 192 - STACK_BIAS;
73 		__asm__ __volatile__("mov %0, %%sp" : : "r" (sp));
74 	}
75 
76 	return orig_sp;
77 }
78 
79 static inline __attribute__((always_inline)) void restore_hardirq_stack(void *orig_sp)
80 {
81 	__asm__ __volatile__("mov %0, %%sp" : : "r" (orig_sp));
82 }
83 
84 #endif /* _KSTACK_H */
85