arch/s390/kernel/mcount.S

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * Copyright IBM Corp. 2008, 2009
   4  *
   5  *   Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>,
   6  *
   7  */
   8
   9 #include <linux/linkage.h>
  10 #include <asm/asm-offsets.h>
  11 #include <asm/ftrace.h>
  12 #include <asm/nospec-insn.h>
  13 #include <asm/ptrace.h>
  14 #include <asm/export.h>
  15
  16         GEN_BR_THUNK %r1
  17         GEN_BR_THUNK %r14
  18
  19         .section .kprobes.text, "ax"
  20
  21 ENTRY(ftrace_stub)
  22         BR_EX   %r14
  23 ENDPROC(ftrace_stub)
  24
  25 #define STACK_FRAME_SIZE  (STACK_FRAME_OVERHEAD + __PT_SIZE)
  26 #define STACK_PTREGS      (STACK_FRAME_OVERHEAD)
  27 #define STACK_PTREGS_GPRS (STACK_PTREGS + __PT_GPRS)
  28 #define STACK_PTREGS_PSW  (STACK_PTREGS + __PT_PSW)
  29
  30 ENTRY(_mcount)
  31         BR_EX   %r14
  32 ENDPROC(_mcount)
  33 EXPORT_SYMBOL(_mcount)
  34
  35 ENTRY(ftrace_caller)
  36         .globl  ftrace_regs_caller
  37         .set    ftrace_regs_caller,ftrace_caller
  38         lgr     %r1,%r15
  39 #if !(defined(CC_USING_HOTPATCH) || defined(CC_USING_NOP_MCOUNT))
  40         aghi    %r0,MCOUNT_RETURN_FIXUP
  41 #endif
  42         aghi    %r15,-STACK_FRAME_SIZE
  43         stg     %r1,__SF_BACKCHAIN(%r15)
  44         stg     %r1,(STACK_PTREGS_GPRS+15*8)(%r15)
  45         stg     %r0,(STACK_PTREGS_PSW+8)(%r15)
  46         stmg    %r2,%r14,(STACK_PTREGS_GPRS+2*8)(%r15)
  47 #ifdef CONFIG_HAVE_MARCH_Z196_FEATURES
  48         aghik   %r2,%r0,-MCOUNT_INSN_SIZE
  49         lgrl    %r4,function_trace_op
  50         lgrl    %r1,ftrace_trace_function
  51 #else
  52         lgr     %r2,%r0
  53         aghi    %r2,-MCOUNT_INSN_SIZE
  54         larl    %r4,function_trace_op
  55         lg      %r4,0(%r4)
  56         larl    %r1,ftrace_trace_function
  57         lg      %r1,0(%r1)
  58 #endif
  59         lgr     %r3,%r14
  60         la      %r5,STACK_PTREGS(%r15)
  61         BASR_EX %r14,%r1
  62 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
  63 # The j instruction gets runtime patched to a nop instruction.
  64 # See ftrace_enable_ftrace_graph_caller.
  65         .globl ftrace_graph_caller
  66 ftrace_graph_caller:
  67         j       ftrace_graph_caller_end
  68         lmg     %r2,%r3,(STACK_PTREGS_GPRS+14*8)(%r15)
  69         lg      %r4,(STACK_PTREGS_PSW+8)(%r15)
  70         brasl   %r14,prepare_ftrace_return
  71         stg     %r2,(STACK_PTREGS_GPRS+14*8)(%r15)
  72 ftrace_graph_caller_end:
  73         .globl  ftrace_graph_caller_end
  74 #endif
  75         lg      %r1,(STACK_PTREGS_PSW+8)(%r15)
  76         lmg     %r2,%r15,(STACK_PTREGS_GPRS+2*8)(%r15)
  77         BR_EX   %r1
  78 ENDPROC(ftrace_caller)
  79
  80 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
  81
  82 ENTRY(return_to_handler)
  83         stmg    %r2,%r5,32(%r15)
  84         lgr     %r1,%r15
  85         aghi    %r15,-STACK_FRAME_OVERHEAD
  86         stg     %r1,__SF_BACKCHAIN(%r15)
  87         brasl   %r14,ftrace_return_to_handler
  88         aghi    %r15,STACK_FRAME_OVERHEAD
  89         lgr     %r14,%r2
  90         lmg     %r2,%r5,32(%r15)
  91         BR_EX   %r14
  92 ENDPROC(return_to_handler)
  93
  94 #endif