xref: /openbmc/linux/arch/s390/kernel/perf_regs.c (revision 680ef72a)
1 #include <linux/perf_event.h>
2 #include <linux/perf_regs.h>
3 #include <linux/kernel.h>
4 #include <linux/errno.h>
5 #include <linux/bug.h>
6 #include <asm/ptrace.h>
7 #include <asm/fpu/api.h>
8 #include <asm/fpu/types.h>
9 
10 u64 perf_reg_value(struct pt_regs *regs, int idx)
11 {
12 	freg_t fp;
13 
14 	if (WARN_ON_ONCE((u32)idx >= PERF_REG_S390_MAX))
15 		return 0;
16 
17 	if (idx >= PERF_REG_S390_R0 && idx <= PERF_REG_S390_R15)
18 		return regs->gprs[idx];
19 
20 	if (idx >= PERF_REG_S390_FP0 && idx <= PERF_REG_S390_FP15) {
21 		if (!user_mode(regs))
22 			return 0;
23 
24 		idx -= PERF_REG_S390_FP0;
25 		fp = MACHINE_HAS_VX ? *(freg_t *)(current->thread.fpu.vxrs + idx)
26 				    : current->thread.fpu.fprs[idx];
27 		return fp.ui;
28 	}
29 
30 	if (idx == PERF_REG_S390_MASK)
31 		return regs->psw.mask;
32 	if (idx == PERF_REG_S390_PC)
33 		return regs->psw.addr;
34 
35 	return regs->gprs[idx];
36 }
37 
38 #define REG_RESERVED (~((1UL << PERF_REG_S390_MAX) - 1))
39 
40 int perf_reg_validate(u64 mask)
41 {
42 	if (!mask || mask & REG_RESERVED)
43 		return -EINVAL;
44 
45 	return 0;
46 }
47 
48 u64 perf_reg_abi(struct task_struct *task)
49 {
50 	if (test_tsk_thread_flag(task, TIF_31BIT))
51 		return PERF_SAMPLE_REGS_ABI_32;
52 
53 	return PERF_SAMPLE_REGS_ABI_64;
54 }
55 
56 void perf_get_regs_user(struct perf_regs *regs_user,
57 			struct pt_regs *regs,
58 			struct pt_regs *regs_user_copy)
59 {
60 	/*
61 	 * Use the regs from the first interruption and let
62 	 * perf_sample_regs_intr() handle interrupts (regs == get_irq_regs()).
63 	 *
64 	 * Also save FPU registers for user-space tasks only.
65 	 */
66 	regs_user->regs = task_pt_regs(current);
67 	if (user_mode(regs_user->regs))
68 		save_fpu_regs();
69 	regs_user->abi = perf_reg_abi(current);
70 }
71