linux/arch/csky/kernel/perf_regs.c
Mao Han daac95e70f csky: Add support for perf registers sampling
This patch implements the perf registers sampling and validation API
for csky arch. The valid registers and their register ID are defined in
perf_regs.h. Perf tool can backtrace in userspace with unwind library
and the registers/user stack dump support.

Signed-off-by: Mao Han <han_mao@c-sky.com>
Signed-off-by: Guo Ren <ren_guo@c-sky.com>
2019-04-22 13:44:57 +08:00

41 lines
847 B
C

// SPDX-License-Identifier: GPL-2.0
// Copyright (C) 2019 Hangzhou C-SKY Microsystems co.,ltd.
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/perf_event.h>
#include <linux/bug.h>
#include <asm/perf_regs.h>
#include <asm/ptrace.h>
u64 perf_reg_value(struct pt_regs *regs, int idx)
{
if (WARN_ON_ONCE((u32)idx >= PERF_REG_CSKY_MAX))
return 0;
return (u64)*((u32 *)regs + idx);
}
#define REG_RESERVED (~((1ULL << PERF_REG_CSKY_MAX) - 1))
int perf_reg_validate(u64 mask)
{
if (!mask || mask & REG_RESERVED)
return -EINVAL;
return 0;
}
u64 perf_reg_abi(struct task_struct *task)
{
return PERF_SAMPLE_REGS_ABI_32;
}
void perf_get_regs_user(struct perf_regs *regs_user,
struct pt_regs *regs,
struct pt_regs *regs_user_copy)
{
regs_user->regs = task_pt_regs(current);
regs_user->abi = perf_reg_abi(current);
}