| /* SPDX-License-Identifier: GPL-2.0-or-later */ |
| /* |
| * Split from entry_32.S |
| */ |
| |
| #include <linux/magic.h> |
| #include <asm/reg.h> |
| #include <asm/ppc_asm.h> |
| #include <asm/asm-offsets.h> |
| #include <asm/ftrace.h> |
| #include <asm/export.h> |
| #include <asm/ptrace.h> |
| |
| _GLOBAL(mcount) |
| _GLOBAL(_mcount) |
| /* |
| * It is required that _mcount on PPC32 must preserve the |
| * link register. But we have r12 to play with. We use r12 |
| * to push the return address back to the caller of mcount |
| * into the ctr register, restore the link register and |
| * then jump back using the ctr register. |
| */ |
| mflr r12 |
| mtctr r12 |
| mtlr r0 |
| bctr |
| EXPORT_SYMBOL(_mcount) |
| |
| _GLOBAL(ftrace_caller) |
| MCOUNT_SAVE_FRAME |
| /* r3 ends up with link register */ |
| subi r3, r3, MCOUNT_INSN_SIZE |
| lis r5,function_trace_op@ha |
| lwz r5,function_trace_op@l(r5) |
| li r6, 0 |
| .globl ftrace_call |
| ftrace_call: |
| bl ftrace_stub |
| nop |
| MCOUNT_RESTORE_FRAME |
| ftrace_caller_common: |
| #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| .globl ftrace_graph_call |
| ftrace_graph_call: |
| b ftrace_graph_stub |
| _GLOBAL(ftrace_graph_stub) |
| #endif |
| /* old link register ends up in ctr reg */ |
| bctr |
| |
| |
| _GLOBAL(ftrace_stub) |
| blr |
| |
| _GLOBAL(ftrace_regs_caller) |
| /* Save the original return address in A's stack frame */ |
| stw r0,LRSAVE(r1) |
| |
| /* Create our stack frame + pt_regs */ |
| stwu r1,-INT_FRAME_SIZE(r1) |
| |
| /* Save all gprs to pt_regs */ |
| stw r0, GPR0(r1) |
| stmw r2, GPR2(r1) |
| |
| /* Save previous stack pointer (r1) */ |
| addi r8, r1, INT_FRAME_SIZE |
| stw r8, GPR1(r1) |
| |
| /* Load special regs for save below */ |
| mfmsr r8 |
| mfctr r9 |
| mfxer r10 |
| mfcr r11 |
| |
| /* Get the _mcount() call site out of LR */ |
| mflr r7 |
| /* Save it as pt_regs->nip */ |
| stw r7, _NIP(r1) |
| /* Save the read LR in pt_regs->link */ |
| stw r0, _LINK(r1) |
| |
| lis r3,function_trace_op@ha |
| lwz r5,function_trace_op@l(r3) |
| |
| /* Calculate ip from nip-4 into r3 for call below */ |
| subi r3, r7, MCOUNT_INSN_SIZE |
| |
| /* Put the original return address in r4 as parent_ip */ |
| mr r4, r0 |
| |
| /* Save special regs */ |
| stw r8, _MSR(r1) |
| stw r9, _CTR(r1) |
| stw r10, _XER(r1) |
| stw r11, _CCR(r1) |
| |
| /* Load &pt_regs in r6 for call below */ |
| addi r6, r1, STACK_FRAME_OVERHEAD |
| |
| /* ftrace_call(r3, r4, r5, r6) */ |
| .globl ftrace_regs_call |
| ftrace_regs_call: |
| bl ftrace_stub |
| nop |
| |
| /* Load ctr with the possibly modified NIP */ |
| lwz r3, _NIP(r1) |
| mtctr r3 |
| |
| /* Restore gprs */ |
| lmw r2, GPR2(r1) |
| |
| /* Restore possibly modified LR */ |
| lwz r0, _LINK(r1) |
| mtlr r0 |
| |
| /* Pop our stack frame */ |
| addi r1, r1, INT_FRAME_SIZE |
| |
| b ftrace_caller_common |
| |
| #ifdef CONFIG_FUNCTION_GRAPH_TRACER |
| _GLOBAL(ftrace_graph_caller) |
| stwu r1,-48(r1) |
| stw r3, 12(r1) |
| stw r4, 16(r1) |
| stw r5, 20(r1) |
| stw r6, 24(r1) |
| stw r7, 28(r1) |
| stw r8, 32(r1) |
| stw r9, 36(r1) |
| stw r10,40(r1) |
| |
| addi r5, r1, 48 |
| mfctr r4 /* ftrace_caller has moved local addr here */ |
| stw r4, 44(r1) |
| mflr r3 /* ftrace_caller has restored LR from stack */ |
| subi r4, r4, MCOUNT_INSN_SIZE |
| |
| bl prepare_ftrace_return |
| nop |
| |
| /* |
| * prepare_ftrace_return gives us the address we divert to. |
| * Change the LR in the callers stack frame to this. |
| */ |
| stw r3,52(r1) |
| mtlr r3 |
| lwz r0,44(r1) |
| mtctr r0 |
| |
| lwz r3, 12(r1) |
| lwz r4, 16(r1) |
| lwz r5, 20(r1) |
| lwz r6, 24(r1) |
| lwz r7, 28(r1) |
| lwz r8, 32(r1) |
| lwz r9, 36(r1) |
| lwz r10,40(r1) |
| |
| addi r1, r1, 48 |
| |
| bctr |
| |
| _GLOBAL(return_to_handler) |
| /* need to save return values */ |
| stwu r1, -32(r1) |
| stw r3, 20(r1) |
| stw r4, 16(r1) |
| stw r31, 12(r1) |
| mr r31, r1 |
| |
| bl ftrace_return_to_handler |
| nop |
| |
| /* return value has real return address */ |
| mtlr r3 |
| |
| lwz r3, 20(r1) |
| lwz r4, 16(r1) |
| lwz r31,12(r1) |
| lwz r1, 0(r1) |
| |
| /* Jump back to real return address */ |
| blr |
| #endif /* CONFIG_FUNCTION_GRAPH_TRACER */ |