arch/s390/kernel/perf_regs.c

   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 }