linux/arch/powerpc/kernel/trace/ftrace_64.S

/*
 * Split from entry_64.S
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */

#include <linux/magic.h>
#include <asm/ppc_asm.h>
#include <asm/asm-offsets.h>
#include <asm/ftrace.h>
#include <asm/ppc-opcode.h>
#include <asm/export.h>

#ifdef CONFIG_DYNAMIC_FTRACE
_GLOBAL(mcount)
_GLOBAL(_mcount)
EXPORT_SYMBOL(_mcount)
	mflr	r12
	mtctr	r12
	mtlr	r0
	bctr

#else /* CONFIG_DYNAMIC_FTRACE */
_GLOBAL_TOC(_mcount)
EXPORT_SYMBOL(_mcount)
	/* Taken from output of objdump from lib64/glibc */
	mflr	r3
	ld	r11, 0(r1)
	stdu	r1, -112(r1)
	std	r3, 128(r1)
	ld	r4, 16(r11)

	subi	r3, r3, MCOUNT_INSN_SIZE
	LOAD_REG_ADDR(r5,ftrace_trace_function)
	ld	r5,0(r5)
	ld	r5,0(r5)
	mtctr	r5
	bctrl
	nop

#ifdef CONFIG_FUNCTION_GRAPH_TRACER
	b	ftrace_graph_caller
#endif
	ld	r0, 128(r1)
	mtlr	r0
	addi	r1, r1, 112
_GLOBAL(ftrace_stub)
	blr
#endif /* CONFIG_DYNAMIC_FTRACE */

#ifdef CONFIG_FUNCTION_GRAPH_TRACER
_GLOBAL(return_to_handler)
	/* need to save return values */
	std	r4,  -32(r1)
	std	r3,  -24(r1)
	/* save TOC */
	std	r2,  -16(r1)
	std	r31, -8(r1)
	mr	r31, r1
	stdu	r1, -112(r1)

	/*
	 * We might be called from a module.
	 * Switch to our TOC to run inside the core kernel.
	 */
	ld	r2, PACATOC(r13)

	bl	ftrace_return_to_handler
	nop

	/* return value has real return address */
	mtlr	r3

	ld	r1, 0(r1)
	ld	r4,  -32(r1)
	ld	r3,  -24(r1)
	ld	r2,  -16(r1)
	ld	r31, -8(r1)

	/* Jump back to real return address */
	blr
#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
powerpc: Split ftrace bits into a separate file entry_*.S now includes a lot more than just kernel entry/exit code. As a first step at cleaning this up, let's split out the ftrace bits into separate files. Also move all related tracing code into a new trace/ subdirectory. No functional changes. Suggested-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> 2017-04-25 19:25:53 +05:30			`/*`
			`* Split from entry_64.S`
			`*`
			`* This program is free software; you can redistribute it and/or`
			`* modify it under the terms of the GNU General Public License`
			`* as published by the Free Software Foundation; either version`
			`* 2 of the License, or (at your option) any later version.`
			`*/`

			`#include <linux/magic.h>`
			`#include <asm/ppc_asm.h>`
			`#include <asm/asm-offsets.h>`
			`#include <asm/ftrace.h>`
			`#include <asm/ppc-opcode.h>`
			`#include <asm/export.h>`

			`#ifdef CONFIG_DYNAMIC_FTRACE`
			`_GLOBAL(mcount)`
			`_GLOBAL(_mcount)`
			`EXPORT_SYMBOL(_mcount)`
			`mflr r12`
			`mtctr r12`
			`mtlr r0`
			`bctr`

powerpc/ftrace/64: Split further based on -mprofile-kernel Split ftrace_64.S further retaining the core ftrace 64-bit aspects in ftrace_64.S and moving ftrace_caller() and ftrace_graph_caller() into separate files based on -mprofile-kernel. The livepatch routines are all now contained within the mprofile file. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> 2017-04-25 19:25:54 +05:30			`#else /* CONFIG_DYNAMIC_FTRACE */`
powerpc: Split ftrace bits into a separate file entry_*.S now includes a lot more than just kernel entry/exit code. As a first step at cleaning this up, let's split out the ftrace bits into separate files. Also move all related tracing code into a new trace/ subdirectory. No functional changes. Suggested-by: Michael Ellerman <mpe@ellerman.id.au> Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> 2017-04-25 19:25:53 +05:30			`_GLOBAL_TOC(_mcount)`
			`EXPORT_SYMBOL(_mcount)`
			`/* Taken from output of objdump from lib64/glibc */`
			`mflr r3`
			`ld r11, 0(r1)`
			`stdu r1, -112(r1)`
			`std r3, 128(r1)`
			`ld r4, 16(r11)`

			`subi r3, r3, MCOUNT_INSN_SIZE`
			`LOAD_REG_ADDR(r5,ftrace_trace_function)`
			`ld r5,0(r5)`
			`ld r5,0(r5)`
			`mtctr r5`
			`bctrl`
			`nop`

			`#ifdef CONFIG_FUNCTION_GRAPH_TRACER`
			`b ftrace_graph_caller`
			`#endif`
			`ld r0, 128(r1)`
			`mtlr r0`
			`addi r1, r1, 112`
			`_GLOBAL(ftrace_stub)`
			`blr`
			`#endif /* CONFIG_DYNAMIC_FTRACE */`

			`#ifdef CONFIG_FUNCTION_GRAPH_TRACER`
			`_GLOBAL(return_to_handler)`
			`/* need to save return values */`
			`std r4, -32(r1)`
			`std r3, -24(r1)`
			`/* save TOC */`
			`std r2, -16(r1)`
			`std r31, -8(r1)`
			`mr r31, r1`
			`stdu r1, -112(r1)`

			`/*`
			`* We might be called from a module.`
			`* Switch to our TOC to run inside the core kernel.`
			`*/`
			`ld r2, PACATOC(r13)`

			`bl ftrace_return_to_handler`
			`nop`

			`/* return value has real return address */`
			`mtlr r3`

			`ld r1, 0(r1)`
			`ld r4, -32(r1)`
			`ld r3, -24(r1)`
			`ld r2, -16(r1)`
			`ld r31, -8(r1)`

			`/* Jump back to real return address */`
			`blr`
			`#endif /* CONFIG_FUNCTION_GRAPH_TRACER */`