arch/powerpc/kernel/trace/ftrace_64_pg_entry.S

   1 /* SPDX-License-Identifier: GPL-2.0-or-later */
   2 /*
   3  * Split from ftrace_64.S
   4  */
   5
   6 #include <linux/export.h>
   7 #include <linux/magic.h>
   8 #include <asm/ppc_asm.h>
   9 #include <asm/asm-offsets.h>
  10 #include <asm/ftrace.h>
  11 #include <asm/ppc-opcode.h>
  12
  13 _GLOBAL_TOC(ftrace_caller)
  14         lbz     r3, PACA_FTRACE_ENABLED(r13)
  15         cmpdi   r3, 0
  16         beqlr
  17
  18         /* Taken from output of objdump from lib64/glibc */
  19         mflr    r3
  20         ld      r11, 0(r1)
  21         stdu    r1, -112(r1)
  22         std     r3, 128(r1)
  23         ld      r4, 16(r11)
  24         subi    r3, r3, MCOUNT_INSN_SIZE
  25 .globl ftrace_call
  26 ftrace_call:
  27         bl      ftrace_stub
  28         nop
  29 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
  30 .globl ftrace_graph_call
  31 ftrace_graph_call:
  32         b       ftrace_graph_stub
  33 _GLOBAL(ftrace_graph_stub)
  34 #endif
  35         ld      r0, 128(r1)
  36         mtlr    r0
  37         addi    r1, r1, 112
  38
  39 _GLOBAL(ftrace_stub)
  40         blr
  41
  42 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
  43 _GLOBAL(ftrace_graph_caller)
  44         addi    r5, r1, 112
  45         /* load r4 with local address */
  46         ld      r4, 128(r1)
  47         subi    r4, r4, MCOUNT_INSN_SIZE
  48
  49         /* Grab the LR out of the caller stack frame */
  50         ld      r11, 112(r1)
  51         ld      r3, 16(r11)
  52
  53         bl      prepare_ftrace_return
  54         nop
  55
  56         /*
  57          * prepare_ftrace_return gives us the address we divert to.
  58          * Change the LR in the callers stack frame to this.
  59          */
  60         ld      r11, 112(r1)
  61         std     r3, 16(r11)
  62
  63         ld      r0, 128(r1)
  64         mtlr    r0
  65         addi    r1, r1, 112
  66         blr
  67 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */
  68
  69 .pushsection ".tramp.ftrace.text","aw",@progbits;
  70 .globl ftrace_tramp_text
  71 ftrace_tramp_text:
  72         .space 32
  73 .popsection
  74
  75 .pushsection ".tramp.ftrace.init","aw",@progbits;
  76 .globl ftrace_tramp_init
  77 ftrace_tramp_init:
  78         .space 32
  79 .popsection
  80
  81 _GLOBAL(mcount)
  82 _GLOBAL(_mcount)
  83 EXPORT_SYMBOL(_mcount)
  84         mflr    r12
  85         mtctr   r12
  86         mtlr    r0
  87         bctr
  88
  89 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
  90 _GLOBAL(return_to_handler)
  91         /* need to save return values */
  92 #ifdef CONFIG_PPC64
  93         std     r4,  -32(r1)
  94         std     r3,  -24(r1)
  95         /* save TOC */
  96         std     r2,  -16(r1)
  97         std     r31, -8(r1)
  98         mr      r31, r1
  99         stdu    r1, -112(r1)
 100
 101         /*
 102          * We might be called from a module.
 103          * Switch to our TOC to run inside the core kernel.
 104          */
 105         LOAD_PACA_TOC()
 106 #else
 107         stwu    r1, -16(r1)
 108         stw     r3, 8(r1)
 109         stw     r4, 12(r1)
 110 #endif
 111
 112         bl      ftrace_return_to_handler
 113         nop
 114
 115         /* return value has real return address */
 116         mtlr    r3
 117
 118 #ifdef CONFIG_PPC64
 119         ld      r1, 0(r1)
 120         ld      r4,  -32(r1)
 121         ld      r3,  -24(r1)
 122         ld      r2,  -16(r1)
 123         ld      r31, -8(r1)
 124 #else
 125         lwz     r3, 8(r1)
 126         lwz     r4, 12(r1)
 127         addi    r1, r1, 16
 128 #endif
 129
 130         /* Jump back to real return address */
 131         blr
 132 #endif /* CONFIG_FUNCTION_GRAPH_TRACER */