xref: /openbmc/linux/arch/sparc/kernel/kstack.h (revision f3539c12)
1 #ifndef _KSTACK_H
2 #define _KSTACK_H
3 
4 #include <linux/thread_info.h>
5 #include <linux/sched.h>
6 #include <asm/ptrace.h>
7 #include <asm/irq.h>
8 
9 /* SP must be STACK_BIAS adjusted already.  */
10 static inline bool kstack_valid(struct thread_info *tp, unsigned long sp)
11 {
12 	unsigned long base = (unsigned long) tp;
13 
14 	/* Stack pointer must be 16-byte aligned.  */
15 	if (sp & (16UL - 1))
16 		return false;
17 
18 	if (sp >= (base + sizeof(struct thread_info)) &&
19 	    sp <= (base + THREAD_SIZE - sizeof(struct sparc_stackf)))
20 		return true;
21 
22 	if (hardirq_stack[tp->cpu]) {
23 		base = (unsigned long) hardirq_stack[tp->cpu];
24 		if (sp >= base &&
25 		    sp <= (base + THREAD_SIZE - sizeof(struct sparc_stackf)))
26 			return true;
27 		base = (unsigned long) softirq_stack[tp->cpu];
28 		if (sp >= base &&
29 		    sp <= (base + THREAD_SIZE - sizeof(struct sparc_stackf)))
30 			return true;
31 	}
32 	return false;
33 }
34 
35 /* Does "regs" point to a valid pt_regs trap frame?  */
36 static inline bool kstack_is_trap_frame(struct thread_info *tp, struct pt_regs *regs)
37 {
38 	unsigned long base = (unsigned long) tp;
39 	unsigned long addr = (unsigned long) regs;
40 
41 	if (addr >= base &&
42 	    addr <= (base + THREAD_SIZE - sizeof(*regs)))
43 		goto check_magic;
44 
45 	if (hardirq_stack[tp->cpu]) {
46 		base = (unsigned long) hardirq_stack[tp->cpu];
47 		if (addr >= base &&
48 		    addr <= (base + THREAD_SIZE - sizeof(*regs)))
49 			goto check_magic;
50 		base = (unsigned long) softirq_stack[tp->cpu];
51 		if (addr >= base &&
52 		    addr <= (base + THREAD_SIZE - sizeof(*regs)))
53 			goto check_magic;
54 	}
55 	return false;
56 
57 check_magic:
58 	if ((regs->magic & ~0x1ff) == PT_REGS_MAGIC)
59 		return true;
60 	return false;
61 
62 }
63 
64 static inline __attribute__((always_inline)) void *set_hardirq_stack(void)
65 {
66 	void *orig_sp, *sp = hardirq_stack[smp_processor_id()];
67 
68 	__asm__ __volatile__("mov %%sp, %0" : "=r" (orig_sp));
69 	if (orig_sp < sp ||
70 	    orig_sp > (sp + THREAD_SIZE)) {
71 		sp += THREAD_SIZE - 192 - STACK_BIAS;
72 		__asm__ __volatile__("mov %0, %%sp" : : "r" (sp));
73 	}
74 
75 	return orig_sp;
76 }
77 
78 static inline __attribute__((always_inline)) void restore_hardirq_stack(void *orig_sp)
79 {
80 	__asm__ __volatile__("mov %0, %%sp" : : "r" (orig_sp));
81 }
82 
83 #endif /* _KSTACK_H */
84