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
10u64 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
37int perf_reg_validate(u64 mask)
38{
39	if (!mask || mask & REG_RESERVED)
40		return -EINVAL;
41
42	return 0;
43}
44
45u64 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
53void 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