projects / linux-2.6-block.git / blame
| Commit | Line | Data |
|---|---|---|
| 2874c5fd | 1 | /* SPDX-License-Identifier: GPL-2.0-or-later */ |
| 7853f9c0 NR |
2 | /* |
| 3 | * Split from entry_32.S | |
| 7853f9c0 NR |
4 | */ |
| 5 | ||
| 6 | #include <linux/magic.h> | |
| 7 | #include <asm/reg.h> | |
| 8 | #include <asm/ppc_asm.h> | |
| 9 | #include <asm/asm-offsets.h> | |
| 10 | #include <asm/ftrace.h> | |
| 11 | #include <asm/export.h> | |
| 12 | ||
| 7853f9c0 NR |
13 | _GLOBAL(mcount) |
| 14 | _GLOBAL(_mcount) | |
| 15 | /* | |
| 16 | * It is required that _mcount on PPC32 must preserve the | |
| 17 | * link register. But we have r0 to play with. We use r0 | |
| 18 | * to push the return address back to the caller of mcount | |
| 19 | * into the ctr register, restore the link register and | |
| 20 | * then jump back using the ctr register. | |
| 21 | */ | |
| 22 | mflr r0 | |
| 23 | mtctr r0 | |
| 24 | lwz r0, 4(r1) | |
| 25 | mtlr r0 | |
| 26 | bctr | |
| 27 | ||
| 28 | _GLOBAL(ftrace_caller) | |
| 29 | MCOUNT_SAVE_FRAME | |
| 30 | /* r3 ends up with link register */ | |
| 31 | subi r3, r3, MCOUNT_INSN_SIZE | |
| 32 | .globl ftrace_call | |
| 33 | ftrace_call: | |
| 34 | bl ftrace_stub | |
| 35 | nop | |
| 36 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
| 37 | .globl ftrace_graph_call | |
| 38 | ftrace_graph_call: | |
| 39 | b ftrace_graph_stub | |
| 40 | _GLOBAL(ftrace_graph_stub) | |
| 41 | #endif | |
| 42 | MCOUNT_RESTORE_FRAME | |
| 43 | /* old link register ends up in ctr reg */ | |
| 44 | bctr | |
| 7853f9c0 | 45 | |
| 7853f9c0 NR |
46 | EXPORT_SYMBOL(_mcount) |
| 47 | ||
| 48 | _GLOBAL(ftrace_stub) | |
| 49 | blr | |
| 50 | ||
| 51 | #ifdef CONFIG_FUNCTION_GRAPH_TRACER | |
| 52 | _GLOBAL(ftrace_graph_caller) | |
| 370011a2 | 53 | addi r5, r1, 48 |
| 7853f9c0 NR |
54 | /* load r4 with local address */ |
| 55 | lwz r4, 44(r1) | |
| 56 | subi r4, r4, MCOUNT_INSN_SIZE | |
| 57 | ||
| 58 | /* Grab the LR out of the caller stack frame */ | |
| 59 | lwz r3,52(r1) | |
| 60 | ||
| 61 | bl prepare_ftrace_return | |
| 62 | nop | |
| 63 | ||
| 64 | /* | |
| 65 | * prepare_ftrace_return gives us the address we divert to. | |
| 66 | * Change the LR in the callers stack frame to this. | |
| 67 | */ | |
| 68 | stw r3,52(r1) | |
| 69 | ||
| 70 | MCOUNT_RESTORE_FRAME | |
| 71 | /* old link register ends up in ctr reg */ | |
| 72 | bctr | |
| 73 | ||
| 74 | _GLOBAL(return_to_handler) | |
| 75 | /* need to save return values */ | |
| 76 | stwu r1, -32(r1) | |
| 77 | stw r3, 20(r1) | |
| 78 | stw r4, 16(r1) | |
| 79 | stw r31, 12(r1) | |
| 80 | mr r31, r1 | |
| 81 | ||
| 82 | bl ftrace_return_to_handler | |
| 83 | nop | |
| 84 | ||
| 85 | /* return value has real return address */ | |
| 86 | mtlr r3 | |
| 87 | ||
| 88 | lwz r3, 20(r1) | |
| 89 | lwz r4, 16(r1) | |
| 90 | lwz r31,12(r1) | |
| 91 | lwz r1, 0(r1) | |
| 92 | ||
| 93 | /* Jump back to real return address */ | |
| 94 | blr | |
| 95 | #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |