xref: /linux/arch/s390/kernel/perf_regs.c (revision 662fa3d6099374c4615bf64d06895e3573b935b2)
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/api.h>
9 #include <asm/fpu/types.h>
10 
11 u64 perf_reg_value(struct pt_regs *regs, int idx)
12 {
13 	freg_t fp;
14 
15 	if (idx >= PERF_REG_S390_R0 && idx <= PERF_REG_S390_R15)
16 		return regs->gprs[idx];
17 
18 	if (idx >= PERF_REG_S390_FP0 && idx <= PERF_REG_S390_FP15) {
19 		if (!user_mode(regs))
20 			return 0;
21 
22 		idx -= PERF_REG_S390_FP0;
23 		fp = MACHINE_HAS_VX ? *(freg_t *)(current->thread.fpu.vxrs + idx)
24 				    : current->thread.fpu.fprs[idx];
25 		return fp.ui;
26 	}
27 
28 	if (idx == PERF_REG_S390_MASK)
29 		return regs->psw.mask;
30 	if (idx == PERF_REG_S390_PC)
31 		return regs->psw.addr;
32 
33 	WARN_ON_ONCE((u32)idx >= PERF_REG_S390_MAX);
34 	return 0;
35 }
36 
37 #define REG_RESERVED (~((1UL << PERF_REG_S390_MAX) - 1))
38 
39 int perf_reg_validate(u64 mask)
40 {
41 	if (!mask || mask & REG_RESERVED)
42 		return -EINVAL;
43 
44 	return 0;
45 }
46 
47 u64 perf_reg_abi(struct task_struct *task)
48 {
49 	if (test_tsk_thread_flag(task, TIF_31BIT))
50 		return PERF_SAMPLE_REGS_ABI_32;
51 
52 	return PERF_SAMPLE_REGS_ABI_64;
53 }
54 
55 void perf_get_regs_user(struct perf_regs *regs_user,
56 			struct pt_regs *regs)
57 {
58 	/*
59 	 * Use the regs from the first interruption and let
60 	 * perf_sample_regs_intr() handle interrupts (regs == get_irq_regs()).
61 	 *
62 	 * Also save FPU registers for user-space tasks only.
63 	 */
64 	regs_user->regs = task_pt_regs(current);
65 	if (user_mode(regs_user->regs))
66 		save_fpu_regs();
67 	regs_user->abi = perf_reg_abi(current);
68 }
69