xref: /linux/arch/s390/kernel/perf_regs.c (revision 24168c5e6dfbdd5b414f048f47f75d64533296ca)
1 // SPDX-License-Identifier: GPL-2.0
2 #include <linux/perf_event.h>
3 #include <linux/perf_regs.h>
4 #include <linux/kernel.h>
5 #include <linux/errno.h>
6 #include <linux/bug.h>
7 #include <asm/ptrace.h>
8 #include <asm/fpu.h>
9 
10 u64 perf_reg_value(struct pt_regs *regs, int idx)
11 {
12 	freg_t fp;
13 
14 	if (idx >= PERF_REG_S390_R0 && idx <= PERF_REG_S390_R15)
15 		return regs->gprs[idx];
16 
17 	if (idx >= PERF_REG_S390_FP0 && idx <= PERF_REG_S390_FP15) {
18 		if (!user_mode(regs))
19 			return 0;
20 
21 		idx -= PERF_REG_S390_FP0;
22 		fp = *(freg_t *)(current->thread.ufpu.vxrs + idx);
23 		return fp.ui;
24 	}
25 
26 	if (idx == PERF_REG_S390_MASK)
27 		return regs->psw.mask;
28 	if (idx == PERF_REG_S390_PC)
29 		return regs->psw.addr;
30 
31 	WARN_ON_ONCE((u32)idx >= PERF_REG_S390_MAX);
32 	return 0;
33 }
34 
35 #define REG_RESERVED (~((1UL << PERF_REG_S390_MAX) - 1))
36 
37 int perf_reg_validate(u64 mask)
38 {
39 	if (!mask || mask & REG_RESERVED)
40 		return -EINVAL;
41 
42 	return 0;
43 }
44 
45 u64 perf_reg_abi(struct task_struct *task)
46 {
47 	if (test_tsk_thread_flag(task, TIF_31BIT))
48 		return PERF_SAMPLE_REGS_ABI_32;
49 
50 	return PERF_SAMPLE_REGS_ABI_64;
51 }
52 
53 void perf_get_regs_user(struct perf_regs *regs_user,
54 			struct pt_regs *regs)
55 {
56 	/*
57 	 * Use the regs from the first interruption and let
58 	 * perf_sample_regs_intr() handle interrupts (regs == get_irq_regs()).
59 	 *
60 	 * Also save FPU registers for user-space tasks only.
61 	 */
62 	regs_user->regs = task_pt_regs(current);
63 	if (user_mode(regs_user->regs))
64 		save_user_fpu_regs();
65 	regs_user->abi = perf_reg_abi(current);
66 }
67