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authorNaveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>2017-04-25 16:55:53 +0300
committerMichael Ellerman <mpe@ellerman.id.au>2017-04-27 15:20:29 +0300
commit7853f9c029ac9134df42ea9e0d6bc600180f268d (patch)
treeda63e31c2899e84a8b38eb3063ac7154a1b219df /arch/powerpc/kernel/trace
parent2505820f7ce2da2ef4ca5bd02fc239df0ba87c9f (diff)
downloadlinux-7853f9c029ac9134df42ea9e0d6bc600180f268d.tar.xz
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>
Diffstat (limited to 'arch/powerpc/kernel/trace')
-rw-r--r--arch/powerpc/kernel/trace/Makefile24
-rw-r--r--arch/powerpc/kernel/trace/ftrace.c620
-rw-r--r--arch/powerpc/kernel/trace/ftrace_32.S118
-rw-r--r--arch/powerpc/kernel/trace/ftrace_64.S389
-rw-r--r--arch/powerpc/kernel/trace/trace_clock.c15
5 files changed, 1166 insertions, 0 deletions
diff --git a/arch/powerpc/kernel/trace/Makefile b/arch/powerpc/kernel/trace/Makefile
new file mode 100644
index 000000000000..5f5a35254a9b
--- /dev/null
+++ b/arch/powerpc/kernel/trace/Makefile
@@ -0,0 +1,24 @@
+#
+# Makefile for the powerpc trace subsystem
+#
+
+subdir-ccflags-$(CONFIG_PPC_WERROR) := -Werror
+
+ifdef CONFIG_FUNCTION_TRACER
+# do not trace tracer code
+CFLAGS_REMOVE_ftrace.o = -mno-sched-epilog $(CC_FLAGS_FTRACE)
+endif
+
+obj32-$(CONFIG_FUNCTION_TRACER) += ftrace_32.o
+obj64-$(CONFIG_FUNCTION_TRACER) += ftrace_64.o
+obj-$(CONFIG_DYNAMIC_FTRACE) += ftrace.o
+obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o
+obj-$(CONFIG_FTRACE_SYSCALLS) += ftrace.o
+obj-$(CONFIG_TRACING) += trace_clock.o
+
+obj-$(CONFIG_PPC64) += $(obj64-y)
+obj-$(CONFIG_PPC32) += $(obj32-y)
+
+# Disable GCOV & sanitizers in odd or sensitive code
+GCOV_PROFILE_ftrace.o := n
+UBSAN_SANITIZE_ftrace.o := n
diff --git a/arch/powerpc/kernel/trace/ftrace.c b/arch/powerpc/kernel/trace/ftrace.c
new file mode 100644
index 000000000000..32509de6ce4c
--- /dev/null
+++ b/arch/powerpc/kernel/trace/ftrace.c
@@ -0,0 +1,620 @@
+/*
+ * Code for replacing ftrace calls with jumps.
+ *
+ * Copyright (C) 2007-2008 Steven Rostedt <srostedt@redhat.com>
+ *
+ * Thanks goes out to P.A. Semi, Inc for supplying me with a PPC64 box.
+ *
+ * Added function graph tracer code, taken from x86 that was written
+ * by Frederic Weisbecker, and ported to PPC by Steven Rostedt.
+ *
+ */
+
+#define pr_fmt(fmt) "ftrace-powerpc: " fmt
+
+#include <linux/spinlock.h>
+#include <linux/hardirq.h>
+#include <linux/uaccess.h>
+#include <linux/module.h>
+#include <linux/ftrace.h>
+#include <linux/percpu.h>
+#include <linux/init.h>
+#include <linux/list.h>
+
+#include <asm/asm-prototypes.h>
+#include <asm/cacheflush.h>
+#include <asm/code-patching.h>
+#include <asm/ftrace.h>
+#include <asm/syscall.h>
+
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+static unsigned int
+ftrace_call_replace(unsigned long ip, unsigned long addr, int link)
+{
+ unsigned int op;
+
+ addr = ppc_function_entry((void *)addr);
+
+ /* if (link) set op to 'bl' else 'b' */
+ op = create_branch((unsigned int *)ip, addr, link ? 1 : 0);
+
+ return op;
+}
+
+static int
+ftrace_modify_code(unsigned long ip, unsigned int old, unsigned int new)
+{
+ unsigned int replaced;
+
+ /*
+ * Note:
+ * We are paranoid about modifying text, as if a bug was to happen, it
+ * could cause us to read or write to someplace that could cause harm.
+ * Carefully read and modify the code with probe_kernel_*(), and make
+ * sure what we read is what we expected it to be before modifying it.
+ */
+
+ /* read the text we want to modify */
+ if (probe_kernel_read(&replaced, (void *)ip, MCOUNT_INSN_SIZE))
+ return -EFAULT;
+
+ /* Make sure it is what we expect it to be */
+ if (replaced != old) {
+ pr_err("%p: replaced (%#x) != old (%#x)",
+ (void *)ip, replaced, old);
+ return -EINVAL;
+ }
+
+ /* replace the text with the new text */
+ if (patch_instruction((unsigned int *)ip, new))
+ return -EPERM;
+
+ return 0;
+}
+
+/*
+ * Helper functions that are the same for both PPC64 and PPC32.
+ */
+static int test_24bit_addr(unsigned long ip, unsigned long addr)
+{
+ addr = ppc_function_entry((void *)addr);
+
+ /* use the create_branch to verify that this offset can be branched */
+ return create_branch((unsigned int *)ip, addr, 0);
+}
+
+#ifdef CONFIG_MODULES
+
+static int is_bl_op(unsigned int op)
+{
+ return (op & 0xfc000003) == 0x48000001;
+}
+
+static unsigned long find_bl_target(unsigned long ip, unsigned int op)
+{
+ static int offset;
+
+ offset = (op & 0x03fffffc);
+ /* make it signed */
+ if (offset & 0x02000000)
+ offset |= 0xfe000000;
+
+ return ip + (long)offset;
+}
+
+#ifdef CONFIG_PPC64
+static int
+__ftrace_make_nop(struct module *mod,
+ struct dyn_ftrace *rec, unsigned long addr)
+{
+ unsigned long entry, ptr, tramp;
+ unsigned long ip = rec->ip;
+ unsigned int op, pop;
+
+ /* read where this goes */
+ if (probe_kernel_read(&op, (void *)ip, sizeof(int))) {
+ pr_err("Fetching opcode failed.\n");
+ return -EFAULT;
+ }
+
+ /* Make sure that that this is still a 24bit jump */
+ if (!is_bl_op(op)) {
+ pr_err("Not expected bl: opcode is %x\n", op);
+ return -EINVAL;
+ }
+
+ /* lets find where the pointer goes */
+ tramp = find_bl_target(ip, op);
+
+ pr_devel("ip:%lx jumps to %lx", ip, tramp);
+
+ if (module_trampoline_target(mod, tramp, &ptr)) {
+ pr_err("Failed to get trampoline target\n");
+ return -EFAULT;
+ }
+
+ pr_devel("trampoline target %lx", ptr);
+
+ entry = ppc_global_function_entry((void *)addr);
+ /* This should match what was called */
+ if (ptr != entry) {
+ pr_err("addr %lx does not match expected %lx\n", ptr, entry);
+ return -EINVAL;
+ }
+
+#ifdef CC_USING_MPROFILE_KERNEL
+ /* When using -mkernel_profile there is no load to jump over */
+ pop = PPC_INST_NOP;
+
+ if (probe_kernel_read(&op, (void *)(ip - 4), 4)) {
+ pr_err("Fetching instruction at %lx failed.\n", ip - 4);
+ return -EFAULT;
+ }
+
+ /* We expect either a mflr r0, or a std r0, LRSAVE(r1) */
+ if (op != PPC_INST_MFLR && op != PPC_INST_STD_LR) {
+ pr_err("Unexpected instruction %08x around bl _mcount\n", op);
+ return -EINVAL;
+ }
+#else
+ /*
+ * Our original call site looks like:
+ *
+ * bl <tramp>
+ * ld r2,XX(r1)
+ *
+ * Milton Miller pointed out that we can not simply nop the branch.
+ * If a task was preempted when calling a trace function, the nops
+ * will remove the way to restore the TOC in r2 and the r2 TOC will
+ * get corrupted.
+ *
+ * Use a b +8 to jump over the load.
+ */
+
+ pop = PPC_INST_BRANCH | 8; /* b +8 */
+
+ /*
+ * Check what is in the next instruction. We can see ld r2,40(r1), but
+ * on first pass after boot we will see mflr r0.
+ */
+ if (probe_kernel_read(&op, (void *)(ip+4), MCOUNT_INSN_SIZE)) {
+ pr_err("Fetching op failed.\n");
+ return -EFAULT;
+ }
+
+ if (op != PPC_INST_LD_TOC) {
+ pr_err("Expected %08x found %08x\n", PPC_INST_LD_TOC, op);
+ return -EINVAL;
+ }
+#endif /* CC_USING_MPROFILE_KERNEL */
+
+ if (patch_instruction((unsigned int *)ip, pop)) {
+ pr_err("Patching NOP failed.\n");
+ return -EPERM;
+ }
+
+ return 0;
+}
+
+#else /* !PPC64 */
+static int
+__ftrace_make_nop(struct module *mod,
+ struct dyn_ftrace *rec, unsigned long addr)
+{
+ unsigned int op;
+ unsigned int jmp[4];
+ unsigned long ip = rec->ip;
+ unsigned long tramp;
+
+ if (probe_kernel_read(&op, (void *)ip, MCOUNT_INSN_SIZE))
+ return -EFAULT;
+
+ /* Make sure that that this is still a 24bit jump */
+ if (!is_bl_op(op)) {
+ pr_err("Not expected bl: opcode is %x\n", op);
+ return -EINVAL;
+ }
+
+ /* lets find where the pointer goes */
+ tramp = find_bl_target(ip, op);
+
+ /*
+ * On PPC32 the trampoline looks like:
+ * 0x3d, 0x80, 0x00, 0x00 lis r12,sym@ha
+ * 0x39, 0x8c, 0x00, 0x00 addi r12,r12,sym@l
+ * 0x7d, 0x89, 0x03, 0xa6 mtctr r12
+ * 0x4e, 0x80, 0x04, 0x20 bctr
+ */
+
+ pr_devel("ip:%lx jumps to %lx", ip, tramp);
+
+ /* Find where the trampoline jumps to */
+ if (probe_kernel_read(jmp, (void *)tramp, sizeof(jmp))) {
+ pr_err("Failed to read %lx\n", tramp);
+ return -EFAULT;
+ }
+
+ pr_devel(" %08x %08x ", jmp[0], jmp[1]);
+
+ /* verify that this is what we expect it to be */
+ if (((jmp[0] & 0xffff0000) != 0x3d800000) ||
+ ((jmp[1] & 0xffff0000) != 0x398c0000) ||
+ (jmp[2] != 0x7d8903a6) ||
+ (jmp[3] != 0x4e800420)) {
+ pr_err("Not a trampoline\n");
+ return -EINVAL;
+ }
+
+ tramp = (jmp[1] & 0xffff) |
+ ((jmp[0] & 0xffff) << 16);
+ if (tramp & 0x8000)
+ tramp -= 0x10000;
+
+ pr_devel(" %lx ", tramp);
+
+ if (tramp != addr) {
+ pr_err("Trampoline location %08lx does not match addr\n",
+ tramp);
+ return -EINVAL;
+ }
+
+ op = PPC_INST_NOP;
+
+ if (patch_instruction((unsigned int *)ip, op))
+ return -EPERM;
+
+ return 0;
+}
+#endif /* PPC64 */
+#endif /* CONFIG_MODULES */
+
+int ftrace_make_nop(struct module *mod,
+ struct dyn_ftrace *rec, unsigned long addr)
+{
+ unsigned long ip = rec->ip;
+ unsigned int old, new;
+
+ /*
+ * If the calling address is more that 24 bits away,
+ * then we had to use a trampoline to make the call.
+ * Otherwise just update the call site.
+ */
+ if (test_24bit_addr(ip, addr)) {
+ /* within range */
+ old = ftrace_call_replace(ip, addr, 1);
+ new = PPC_INST_NOP;
+ return ftrace_modify_code(ip, old, new);
+ }
+
+#ifdef CONFIG_MODULES
+ /*
+ * Out of range jumps are called from modules.
+ * We should either already have a pointer to the module
+ * or it has been passed in.
+ */
+ if (!rec->arch.mod) {
+ if (!mod) {
+ pr_err("No module loaded addr=%lx\n", addr);
+ return -EFAULT;
+ }
+ rec->arch.mod = mod;
+ } else if (mod) {
+ if (mod != rec->arch.mod) {
+ pr_err("Record mod %p not equal to passed in mod %p\n",
+ rec->arch.mod, mod);
+ return -EINVAL;
+ }
+ /* nothing to do if mod == rec->arch.mod */
+ } else
+ mod = rec->arch.mod;
+
+ return __ftrace_make_nop(mod, rec, addr);
+#else
+ /* We should not get here without modules */
+ return -EINVAL;
+#endif /* CONFIG_MODULES */
+}
+
+#ifdef CONFIG_MODULES
+#ifdef CONFIG_PPC64
+/*
+ * Examine the existing instructions for __ftrace_make_call.
+ * They should effectively be a NOP, and follow formal constraints,
+ * depending on the ABI. Return false if they don't.
+ */
+#ifndef CC_USING_MPROFILE_KERNEL
+static int
+expected_nop_sequence(void *ip, unsigned int op0, unsigned int op1)
+{
+ /*
+ * We expect to see:
+ *
+ * b +8
+ * ld r2,XX(r1)
+ *
+ * The load offset is different depending on the ABI. For simplicity
+ * just mask it out when doing the compare.
+ */
+ if ((op0 != 0x48000008) || ((op1 & 0xffff0000) != 0xe8410000))
+ return 0;
+ return 1;
+}
+#else
+static int
+expected_nop_sequence(void *ip, unsigned int op0, unsigned int op1)
+{
+ /* look for patched "NOP" on ppc64 with -mprofile-kernel */
+ if (op0 != PPC_INST_NOP)
+ return 0;
+ return 1;
+}
+#endif
+
+static int
+__ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
+{
+ unsigned int op[2];
+ void *ip = (void *)rec->ip;
+
+ /* read where this goes */
+ if (probe_kernel_read(op, ip, sizeof(op)))
+ return -EFAULT;
+
+ if (!expected_nop_sequence(ip, op[0], op[1])) {
+ pr_err("Unexpected call sequence at %p: %x %x\n",
+ ip, op[0], op[1]);
+ return -EINVAL;
+ }
+
+ /* If we never set up a trampoline to ftrace_caller, then bail */
+ if (!rec->arch.mod->arch.tramp) {
+ pr_err("No ftrace trampoline\n");
+ return -EINVAL;
+ }
+
+ /* Ensure branch is within 24 bits */
+ if (!create_branch(ip, rec->arch.mod->arch.tramp, BRANCH_SET_LINK)) {
+ pr_err("Branch out of range\n");
+ return -EINVAL;
+ }
+
+ if (patch_branch(ip, rec->arch.mod->arch.tramp, BRANCH_SET_LINK)) {
+ pr_err("REL24 out of range!\n");
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+#ifdef CONFIG_DYNAMIC_FTRACE_WITH_REGS
+int ftrace_modify_call(struct dyn_ftrace *rec, unsigned long old_addr,
+ unsigned long addr)
+{
+ return ftrace_make_call(rec, addr);
+}
+#endif
+
+#else /* !CONFIG_PPC64: */
+static int
+__ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
+{
+ unsigned int op;
+ unsigned long ip = rec->ip;
+
+ /* read where this goes */
+ if (probe_kernel_read(&op, (void *)ip, MCOUNT_INSN_SIZE))
+ return -EFAULT;
+
+ /* It should be pointing to a nop */
+ if (op != PPC_INST_NOP) {
+ pr_err("Expected NOP but have %x\n", op);
+ return -EINVAL;
+ }
+
+ /* If we never set up a trampoline to ftrace_caller, then bail */
+ if (!rec->arch.mod->arch.tramp) {
+ pr_err("No ftrace trampoline\n");
+ return -EINVAL;
+ }
+
+ /* create the branch to the trampoline */
+ op = create_branch((unsigned int *)ip,
+ rec->arch.mod->arch.tramp, BRANCH_SET_LINK);
+ if (!op) {
+ pr_err("REL24 out of range!\n");
+ return -EINVAL;
+ }
+
+ pr_devel("write to %lx\n", rec->ip);
+
+ if (patch_instruction((unsigned int *)ip, op))
+ return -EPERM;
+
+ return 0;
+}
+#endif /* CONFIG_PPC64 */
+#endif /* CONFIG_MODULES */
+
+int ftrace_make_call(struct dyn_ftrace *rec, unsigned long addr)
+{
+ unsigned long ip = rec->ip;
+ unsigned int old, new;
+
+ /*
+ * If the calling address is more that 24 bits away,
+ * then we had to use a trampoline to make the call.
+ * Otherwise just update the call site.
+ */
+ if (test_24bit_addr(ip, addr)) {
+ /* within range */
+ old = PPC_INST_NOP;
+ new = ftrace_call_replace(ip, addr, 1);
+ return ftrace_modify_code(ip, old, new);
+ }
+
+#ifdef CONFIG_MODULES
+ /*
+ * Out of range jumps are called from modules.
+ * Being that we are converting from nop, it had better
+ * already have a module defined.
+ */
+ if (!rec->arch.mod) {
+ pr_err("No module loaded\n");
+ return -EINVAL;
+ }
+
+ return __ftrace_make_call(rec, addr);
+#else
+ /* We should not get here without modules */
+ return -EINVAL;
+#endif /* CONFIG_MODULES */
+}
+
+int ftrace_update_ftrace_func(ftrace_func_t func)
+{
+ unsigned long ip = (unsigned long)(&ftrace_call);
+ unsigned int old, new;
+ int ret;
+
+ old = *(unsigned int *)&ftrace_call;
+ new = ftrace_call_replace(ip, (unsigned long)func, 1);
+ ret = ftrace_modify_code(ip, old, new);
+
+ return ret;
+}
+
+static int __ftrace_replace_code(struct dyn_ftrace *rec, int enable)
+{
+ unsigned long ftrace_addr = (unsigned long)FTRACE_ADDR;
+ int ret;
+
+ ret = ftrace_update_record(rec, enable);
+
+ switch (ret) {
+ case FTRACE_UPDATE_IGNORE:
+ return 0;
+ case FTRACE_UPDATE_MAKE_CALL:
+ return ftrace_make_call(rec, ftrace_addr);
+ case FTRACE_UPDATE_MAKE_NOP:
+ return ftrace_make_nop(NULL, rec, ftrace_addr);
+ }
+
+ return 0;
+}
+
+void ftrace_replace_code(int enable)
+{
+ struct ftrace_rec_iter *iter;
+ struct dyn_ftrace *rec;
+ int ret;
+
+ for (iter = ftrace_rec_iter_start(); iter;
+ iter = ftrace_rec_iter_next(iter)) {
+ rec = ftrace_rec_iter_record(iter);
+ ret = __ftrace_replace_code(rec, enable);
+ if (ret) {
+ ftrace_bug(ret, rec);
+ return;
+ }
+ }
+}
+
+/*
+ * Use the default ftrace_modify_all_code, but without
+ * stop_machine().
+ */
+void arch_ftrace_update_code(int command)
+{
+ ftrace_modify_all_code(command);
+}
+
+int __init ftrace_dyn_arch_init(void)
+{
+ return 0;
+}
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+extern void ftrace_graph_call(void);
+extern void ftrace_graph_stub(void);
+
+int ftrace_enable_ftrace_graph_caller(void)
+{
+ unsigned long ip = (unsigned long)(&ftrace_graph_call);
+ unsigned long addr = (unsigned long)(&ftrace_graph_caller);
+ unsigned long stub = (unsigned long)(&ftrace_graph_stub);
+ unsigned int old, new;
+
+ old = ftrace_call_replace(ip, stub, 0);
+ new = ftrace_call_replace(ip, addr, 0);
+
+ return ftrace_modify_code(ip, old, new);
+}
+
+int ftrace_disable_ftrace_graph_caller(void)
+{
+ unsigned long ip = (unsigned long)(&ftrace_graph_call);
+ unsigned long addr = (unsigned long)(&ftrace_graph_caller);
+ unsigned long stub = (unsigned long)(&ftrace_graph_stub);
+ unsigned int old, new;
+
+ old = ftrace_call_replace(ip, addr, 0);
+ new = ftrace_call_replace(ip, stub, 0);
+
+ return ftrace_modify_code(ip, old, new);
+}
+#endif /* CONFIG_DYNAMIC_FTRACE */
+
+/*
+ * Hook the return address and push it in the stack of return addrs
+ * in current thread info. Return the address we want to divert to.
+ */
+unsigned long prepare_ftrace_return(unsigned long parent, unsigned long ip)
+{
+ struct ftrace_graph_ent trace;
+ unsigned long return_hooker;
+
+ if (unlikely(ftrace_graph_is_dead()))
+ goto out;
+
+ if (unlikely(atomic_read(&current->tracing_graph_pause)))
+ goto out;
+
+ return_hooker = ppc_function_entry(return_to_handler);
+
+ trace.func = ip;
+ trace.depth = current->curr_ret_stack + 1;
+
+ /* Only trace if the calling function expects to */
+ if (!ftrace_graph_entry(&trace))
+ goto out;
+
+ if (ftrace_push_return_trace(parent, ip, &trace.depth, 0,
+ NULL) == -EBUSY)
+ goto out;
+
+ parent = return_hooker;
+out:
+ return parent;
+}
+#endif /* CONFIG_FUNCTION_GRAPH_TRACER */
+
+#if defined(CONFIG_FTRACE_SYSCALLS) && defined(CONFIG_PPC64)
+unsigned long __init arch_syscall_addr(int nr)
+{
+ return sys_call_table[nr*2];
+}
+#endif /* CONFIG_FTRACE_SYSCALLS && CONFIG_PPC64 */
+
+#ifdef PPC64_ELF_ABI_v1
+char *arch_ftrace_match_adjust(char *str, const char *search)
+{
+ if (str[0] == '.' && search[0] != '.')
+ return str + 1;
+ else
+ return str;
+}
+#endif /* PPC64_ELF_ABI_v1 */
diff --git a/arch/powerpc/kernel/trace/ftrace_32.S b/arch/powerpc/kernel/trace/ftrace_32.S
new file mode 100644
index 000000000000..afef2c076282
--- /dev/null
+++ b/arch/powerpc/kernel/trace/ftrace_32.S
@@ -0,0 +1,118 @@
+/*
+ * Split from entry_32.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/reg.h>
+#include <asm/ppc_asm.h>
+#include <asm/asm-offsets.h>
+#include <asm/ftrace.h>
+#include <asm/export.h>
+
+#ifdef CONFIG_DYNAMIC_FTRACE
+_GLOBAL(mcount)
+_GLOBAL(_mcount)
+ /*
+ * It is required that _mcount on PPC32 must preserve the
+ * link register. But we have r0 to play with. We use r0
+ * 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 r0
+ mtctr r0
+ lwz r0, 4(r1)
+ mtlr r0
+ bctr
+
+_GLOBAL(ftrace_caller)
+ MCOUNT_SAVE_FRAME
+ /* r3 ends up with link register */
+ subi r3, r3, MCOUNT_INSN_SIZE
+.globl ftrace_call
+ftrace_call:
+ bl ftrace_stub
+ nop
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+.globl ftrace_graph_call
+ftrace_graph_call:
+ b ftrace_graph_stub
+_GLOBAL(ftrace_graph_stub)
+#endif
+ MCOUNT_RESTORE_FRAME
+ /* old link register ends up in ctr reg */
+ bctr
+#else
+_GLOBAL(mcount)
+_GLOBAL(_mcount)
+
+ MCOUNT_SAVE_FRAME
+
+ subi r3, r3, MCOUNT_INSN_SIZE
+ LOAD_REG_ADDR(r5, ftrace_trace_function)
+ lwz r5,0(r5)
+
+ mtctr r5
+ bctrl
+ nop
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+ b ftrace_graph_caller
+#endif
+ MCOUNT_RESTORE_FRAME
+ bctr
+#endif
+EXPORT_SYMBOL(_mcount)
+
+_GLOBAL(ftrace_stub)
+ blr
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+_GLOBAL(ftrace_graph_caller)
+ /* load r4 with local address */
+ lwz r4, 44(r1)
+ subi r4, r4, MCOUNT_INSN_SIZE
+
+ /* Grab the LR out of the caller stack frame */
+ lwz r3,52(r1)
+
+ 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)
+
+ MCOUNT_RESTORE_FRAME
+ /* old link register ends up in ctr reg */
+ 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 */
diff --git a/arch/powerpc/kernel/trace/ftrace_64.S b/arch/powerpc/kernel/trace/ftrace_64.S
new file mode 100644
index 000000000000..587e7b5c0aff
--- /dev/null
+++ b/arch/powerpc/kernel/trace/ftrace_64.S
@@ -0,0 +1,389 @@
+/*
+ * 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
+
+#ifndef CC_USING_MPROFILE_KERNEL
+_GLOBAL_TOC(ftrace_caller)
+ /* 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
+.globl ftrace_call
+ftrace_call:
+ bl ftrace_stub
+ nop
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+.globl ftrace_graph_call
+ftrace_graph_call:
+ b ftrace_graph_stub
+_GLOBAL(ftrace_graph_stub)
+#endif
+ ld r0, 128(r1)
+ mtlr r0
+ addi r1, r1, 112
+
+#else /* CC_USING_MPROFILE_KERNEL */
+/*
+ *
+ * ftrace_caller() is the function that replaces _mcount() when ftrace is
+ * active.
+ *
+ * We arrive here after a function A calls function B, and we are the trace
+ * function for B. When we enter r1 points to A's stack frame, B has not yet
+ * had a chance to allocate one yet.
+ *
+ * Additionally r2 may point either to the TOC for A, or B, depending on
+ * whether B did a TOC setup sequence before calling us.
+ *
+ * On entry the LR points back to the _mcount() call site, and r0 holds the
+ * saved LR as it was on entry to B, ie. the original return address at the
+ * call site in A.
+ *
+ * Our job is to save the register state into a struct pt_regs (on the stack)
+ * and then arrange for the ftrace function to be called.
+ */
+_GLOBAL(ftrace_caller)
+ /* Save the original return address in A's stack frame */
+ std r0,LRSAVE(r1)
+
+ /* Create our stack frame + pt_regs */
+ stdu r1,-SWITCH_FRAME_SIZE(r1)
+
+ /* Save all gprs to pt_regs */
+ SAVE_8GPRS(0,r1)
+ SAVE_8GPRS(8,r1)
+ SAVE_8GPRS(16,r1)
+ SAVE_8GPRS(24,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 */
+ std r7, _NIP(r1)
+ /* Save the read LR in pt_regs->link */
+ std r0, _LINK(r1)
+
+ /* Save callee's TOC in the ABI compliant location */
+ std r2, 24(r1)
+ ld r2,PACATOC(r13) /* get kernel TOC in r2 */
+
+ addis r3,r2,function_trace_op@toc@ha
+ addi r3,r3,function_trace_op@toc@l
+ ld r5,0(r3)
+
+#ifdef CONFIG_LIVEPATCH
+ mr r14,r7 /* remember old NIP */
+#endif
+ /* 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 */
+ std r8, _MSR(r1)
+ std r9, _CTR(r1)
+ std r10, _XER(r1)
+ std 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_call
+ftrace_call:
+ bl ftrace_stub
+ nop
+
+ /* Load ctr with the possibly modified NIP */
+ ld r3, _NIP(r1)
+ mtctr r3
+#ifdef CONFIG_LIVEPATCH
+ cmpd r14,r3 /* has NIP been altered? */
+#endif
+
+ /* Restore gprs */
+ REST_8GPRS(0,r1)
+ REST_8GPRS(8,r1)
+ REST_8GPRS(16,r1)
+ REST_8GPRS(24,r1)
+
+ /* Restore possibly modified LR */
+ ld r0, _LINK(r1)
+ mtlr r0
+
+ /* Restore callee's TOC */
+ ld r2, 24(r1)
+
+ /* Pop our stack frame */
+ addi r1, r1, SWITCH_FRAME_SIZE
+
+#ifdef CONFIG_LIVEPATCH
+ /* Based on the cmpd above, if the NIP was altered handle livepatch */
+ bne- livepatch_handler
+#endif
+
+#ifdef CONFIG_FUNCTION_GRAPH_TRACER
+.globl ftrace_graph_call
+ftrace_graph_call:
+ b ftrace_graph_stub
+_GLOBAL(ftrace_graph_stub)
+#endif
+
+ bctr /* jump after _mcount site */
+#endif /* CC_USING_MPROFILE_KERNEL */
+
+_GLOBAL(ftrace_stub)
+ blr
+
+#ifdef CONFIG_LIVEPATCH
+ /*
+ * This function runs in the mcount context, between two functions. As
+ * such it can only clobber registers which are volatile and used in
+ * function linkage.
+ *
+ * We get here when a function A, calls another function B, but B has
+ * been live patched with a new function C.
+ *
+ * On entry:
+ * - we have no stack frame and can not allocate one
+ * - LR points back to the original caller (in A)
+ * - CTR holds the new NIP in C
+ * - r0 & r12 are free
+ *
+ * r0 can't be used as the base register for a DS-form load or store, so
+ * we temporarily shuffle r1 (stack pointer) into r0 and then put it back.
+ */
+livepatch_handler:
+ CURRENT_THREAD_INFO(r12, r1)
+
+ /* Save stack pointer into r0 */
+ mr r0, r1
+
+ /* Allocate 3 x 8 bytes */
+ ld r1, TI_livepatch_sp(r12)
+ addi r1, r1, 24
+ std r1, TI_livepatch_sp(r12)
+
+ /* Save toc & real LR on livepatch stack */
+ std r2, -24(r1)
+ mflr r12
+ std r12, -16(r1)
+
+ /* Store stack end marker */
+ lis r12, STACK_END_MAGIC@h
+ ori r12, r12, STACK_END_MAGIC@l
+ std r12, -8(r1)
+
+ /* Restore real stack pointer */
+ mr r1, r0
+
+ /* Put ctr in r12 for global entry and branch there */
+ mfctr r12
+ bctrl
+
+ /*
+ * Now we are returning from the patched function to the original
+ * caller A. We are free to use r0 and r12, and we can use r2 until we
+ * restore it.
+ */
+
+ CURRENT_THREAD_INFO(r12, r1)
+
+ /* Save stack pointer into r0 */
+ mr r0, r1
+
+ ld r1, TI_livepatch_sp(r12)
+
+ /* Check stack marker hasn't been trashed */
+ lis r2, STACK_END_MAGIC@h
+ ori r2, r2, STACK_END_MAGIC@l
+ ld r12, -8(r1)
+1: tdne r12, r2
+ EMIT_BUG_ENTRY 1b, __FILE__, __LINE__ - 1, 0
+
+ /* Restore LR & toc from livepatch stack */
+ ld r12, -16(r1)
+ mtlr r12
+ ld r2, -24(r1)
+
+ /* Pop livepatch stack frame */
+ CURRENT_THREAD_INFO(r12, r0)
+ subi r1, r1, 24
+ std r1, TI_livepatch_sp(r12)
+
+ /* Restore real stack pointer */
+ mr r1, r0
+
+ /* Return to original caller of live patched function */
+ blr
+#endif
+
+
+#else
+_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
+#ifndef CC_USING_MPROFILE_KERNEL
+_GLOBAL(ftrace_graph_caller)
+ /* load r4 with local address */
+ ld r4, 128(r1)
+ subi r4, r4, MCOUNT_INSN_SIZE
+
+ /* Grab the LR out of the caller stack frame */
+ ld r11, 112(r1)
+ ld r3, 16(r11)
+
+ 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.
+ */
+ ld r11, 112(r1)
+ std r3, 16(r11)
+
+ ld r0, 128(r1)
+ mtlr r0
+ addi r1, r1, 112
+ blr
+
+#else /* CC_USING_MPROFILE_KERNEL */
+_GLOBAL(ftrace_graph_caller)
+ stdu r1, -112(r1)
+ /* with -mprofile-kernel, parameter regs are still alive at _mcount */
+ std r10, 104(r1)
+ std r9, 96(r1)
+ std r8, 88(r1)
+ std r7, 80(r1)
+ std r6, 72(r1)
+ std r5, 64(r1)
+ std r4, 56(r1)
+ std r3, 48(r1)
+
+ /* Save callee's TOC in the ABI compliant location */
+ std r2, 24(r1)
+ ld r2, PACATOC(r13) /* get kernel TOC in r2 */
+
+ mfctr r4 /* ftrace_caller has moved local addr here */
+ std r4, 40(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 to this.
+ */
+ mtlr r3
+
+ ld r0, 40(r1)
+ mtctr r0
+ ld r10, 104(r1)
+ ld r9, 96(r1)
+ ld r8, 88(r1)
+ ld r7, 80(r1)
+ ld r6, 72(r1)
+ ld r5, 64(r1)
+ ld r4, 56(r1)
+ ld r3, 48(r1)
+
+ /* Restore callee's TOC */
+ ld r2, 24(r1)
+
+ addi r1, r1, 112
+ mflr r0
+ std r0, LRSAVE(r1)
+ bctr
+#endif /* CC_USING_MPROFILE_KERNEL */
+
+_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 */
diff --git a/arch/powerpc/kernel/trace/trace_clock.c b/arch/powerpc/kernel/trace/trace_clock.c
new file mode 100644
index 000000000000..49170690946d
--- /dev/null
+++ b/arch/powerpc/kernel/trace/trace_clock.c
@@ -0,0 +1,15 @@
+/*
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License, version 2, as
+ * published by the Free Software Foundation.
+ *
+ * Copyright (C) 2015 Naveen N. Rao, IBM Corporation
+ */
+
+#include <asm/trace_clock.h>
+#include <asm/time.h>
+
+u64 notrace trace_clock_ppc_tb(void)
+{
+ return get_tb();
+}