metag: ftrace support (00512bdd) · Commits · e / devices / android_kernel_fairphone_FP4

arch/metag/Kconfig

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		@@ -12,7 +12,12 @@ config METAG
		select GENERIC_SMP_IDLE_THREAD
		select HAVE_64BIT_ALIGNED_ACCESS
		select HAVE_ARCH_TRACEHOOK
		select HAVE_C_RECORDMCOUNT
		select HAVE_DEBUG_KMEMLEAK
		select HAVE_DYNAMIC_FTRACE
		select HAVE_FTRACE_MCOUNT_RECORD
		select HAVE_FUNCTION_TRACER
		select HAVE_FUNCTION_TRACE_MCOUNT_TEST
		select HAVE_GENERIC_HARDIRQS
		select HAVE_IRQ_WORK
		select HAVE_KERNEL_BZIP2

arch/metag/include/asm/Kbuild

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		@@ -11,7 +11,6 @@ generic-y += errno.h
		generic-y += exec.h
		generic-y += fb.h
		generic-y += fcntl.h
		generic-y += ftrace.h
		generic-y += futex.h
		generic-y += hardirq.h
		generic-y += hw_irq.h

arch/metag/include/asm/ftrace.h

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		#ifndef _ASM_METAG_FTRACE
		#define _ASM_METAG_FTRACE

		#ifdef CONFIG_FUNCTION_TRACER
		#define MCOUNT_INSN_SIZE 8 /* sizeof mcount call */

		#ifndef __ASSEMBLY__
		extern void mcount_wrapper(void);
		#define MCOUNT_ADDR ((long)(mcount_wrapper))

		static inline unsigned long ftrace_call_adjust(unsigned long addr)
		{
		return addr;
		}

		struct dyn_arch_ftrace {
		/* No extra data needed on metag */
		};
		#endif /* __ASSEMBLY__ */

		#endif /* CONFIG_FUNCTION_TRACER */

		#endif /* _ASM_METAG_FTRACE */

arch/metag/kernel/ftrace.c

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		/*
		* Copyright (C) 2008 Imagination Technologies Ltd.
		* Licensed under the GPL
		*
		* Dynamic ftrace support.
		*/

		#include <linux/ftrace.h>
		#include <linux/io.h>
		#include <linux/uaccess.h>

		#include <asm/cacheflush.h>

		#define D04_MOVT_TEMPLATE 0x02200005
		#define D04_CALL_TEMPLATE 0xAC200005
		#define D1RTP_MOVT_TEMPLATE 0x03200005
		#define D1RTP_CALL_TEMPLATE 0xAC200006

		static const unsigned long NOP[2] = {0xa0fffffe, 0xa0fffffe};
		static unsigned long movt_and_call_insn[2];

		static unsigned char *ftrace_nop_replace(void)
		{
		return (char *)&NOP[0];
		}

		static unsigned char *ftrace_call_replace(unsigned long pc, unsigned long addr)
		{
		unsigned long hi16, low16;

		hi16 = (addr & 0xffff0000) >> 13;
		low16 = (addr & 0x0000ffff) << 3;

		/*
		* The compiler makes the call to mcount_wrapper()
		* (Meta's wrapper around mcount()) through the register
		* D0.4. So whenever we're patching one of those compiler-generated
		* calls we also need to go through D0.4. Otherwise use D1RtP.
		*/
		if (pc == (unsigned long)&ftrace_call) {
		writel(D1RTP_MOVT_TEMPLATE \| hi16, &movt_and_call_insn[0]);
		writel(D1RTP_CALL_TEMPLATE \| low16, &movt_and_call_insn[1]);
		} else {
		writel(D04_MOVT_TEMPLATE \| hi16, &movt_and_call_insn[0]);
		writel(D04_CALL_TEMPLATE \| low16, &movt_and_call_insn[1]);
		}

		return (unsigned char *)&movt_and_call_insn[0];
		}

		static int ftrace_modify_code(unsigned long pc, unsigned char *old_code,
		unsigned char *new_code)
		{
		unsigned char replaced[MCOUNT_INSN_SIZE];

		/*
		* Note: Due to modules and __init, code can
		* disappear and change, we need to protect against faulting
		* as well as code changing.
		*
		* No real locking needed, this code is run through
		* kstop_machine.
		*/

		/* read the text we want to modify */
		if (probe_kernel_read(replaced, (void *)pc, MCOUNT_INSN_SIZE))
		return -EFAULT;

		/* Make sure it is what we expect it to be */
		if (memcmp(replaced, old_code, MCOUNT_INSN_SIZE) != 0)
		return -EINVAL;

		/* replace the text with the new text */
		if (probe_kernel_write((void *)pc, new_code, MCOUNT_INSN_SIZE))
		return -EPERM;

		flush_icache_range(pc, pc + MCOUNT_INSN_SIZE);

		return 0;
		}

		int ftrace_update_ftrace_func(ftrace_func_t func)
		{
		int ret;
		unsigned long pc;
		unsigned char old[MCOUNT_INSN_SIZE], *new;

		pc = (unsigned long)&ftrace_call;
		memcpy(old, &ftrace_call, MCOUNT_INSN_SIZE);
		new = ftrace_call_replace(pc, (unsigned long)func);
		ret = ftrace_modify_code(pc, old, new);

		return ret;
		}

		int ftrace_make_nop(struct module *mod,
		struct dyn_ftrace *rec, unsigned long addr)
		{
		unsigned char new, old;
		unsigned long ip = rec->ip;

		old = ftrace_call_replace(ip, addr);
		new = ftrace_nop_replace();

		return ftrace_modify_code(ip, old, new);
		}

		int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
		{
		unsigned char new, old;
		unsigned long ip = rec->ip;

		old = ftrace_nop_replace();
		new = ftrace_call_replace(ip, addr);

		return ftrace_modify_code(ip, old, new);
		}

		/* run from kstop_machine */
		int __init ftrace_dyn_arch_init(void *data)
		{
		/* The return code is returned via data */
		writel(0, data);

		return 0;
		}

arch/metag/kernel/ftrace_stub.S

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		/*
		* Copyright (C) 2008 Imagination Technologies Ltd.
		* Licensed under the GPL
		*
		*/

		#include <asm/ftrace.h>

		.text
		#ifdef CONFIG_DYNAMIC_FTRACE
		.global _mcount_wrapper
		.type _mcount_wrapper,function
		_mcount_wrapper:
		MOV PC,D0.4

		.global _ftrace_caller
		.type _ftrace_caller,function
		_ftrace_caller:
		MOVT D0Re0,#HI(_function_trace_stop)
		ADD D0Re0,D0Re0,#LO(_function_trace_stop)
		GETD D0Re0,[D0Re0]
		CMP D0Re0,#0
		BEQ $Lcall_stub
		MOV PC,D0.4
		$Lcall_stub:
		MSETL [A0StP], D0Ar6, D0Ar4, D0Ar2, D0.4
		MOV D1Ar1, D0.4
		MOV D0Ar2, D1RtP
		SUB D1Ar1,D1Ar1,#MCOUNT_INSN_SIZE

		.global _ftrace_call
		_ftrace_call:
		MOVT D1RtP,#HI(_ftrace_stub)
		CALL D1RtP,#LO(_ftrace_stub)
		GETL D0.4, D1RtP, [A0StP++#(-8)]
		GETL D0Ar2, D1Ar1, [A0StP++#(-8)]
		GETL D0Ar4, D1Ar3, [A0StP++#(-8)]
		GETL D0Ar6, D1Ar5, [A0StP++#(-8)]
		MOV PC, D0.4
		#else

		.global _mcount_wrapper
		.type _mcount_wrapper,function
		_mcount_wrapper:
		MOVT D0Re0,#HI(_function_trace_stop)
		ADD D0Re0,D0Re0,#LO(_function_trace_stop)
		GETD D0Re0,[D0Re0]
		CMP D0Re0,#0
		BEQ $Lcall_mcount
		MOV PC,D0.4
		$Lcall_mcount:
		MSETL [A0StP], D0Ar6, D0Ar4, D0Ar2, D0.4
		MOV D1Ar1, D0.4
		MOV D0Ar2, D1RtP
		MOVT D0Re0,#HI(_ftrace_trace_function)
		ADD D0Re0,D0Re0,#LO(_ftrace_trace_function)
		GET D1Ar3,[D0Re0]
		MOVT D1Re0,#HI(_ftrace_stub)
		ADD D1Re0,D1Re0,#LO(_ftrace_stub)
		CMP D1Ar3,D1Re0
		BEQ $Ltrace_exit
		MOV D1RtP,D1Ar3
		SUB D1Ar1,D1Ar1,#MCOUNT_INSN_SIZE
		SWAP PC,D1RtP
		$Ltrace_exit:
		GETL D0.4, D1RtP, [A0StP++#(-8)]
		GETL D0Ar2, D1Ar1, [A0StP++#(-8)]
		GETL D0Ar4, D1Ar3, [A0StP++#(-8)]
		GETL D0Ar6, D1Ar5, [A0StP++#(-8)]
		MOV PC, D0.4

		#endif /* CONFIG_DYNAMIC_FTRACE */

		.global _ftrace_stub
		_ftrace_stub:
		MOV PC,D1RtP