diff options
Diffstat (limited to 'arch/tile/kernel')
-rw-r--r-- | arch/tile/kernel/Makefile | 6 | ||||
-rw-r--r-- | arch/tile/kernel/ftrace.c | 246 | ||||
-rw-r--r-- | arch/tile/kernel/mcount_64.S | 224 | ||||
-rw-r--r-- | arch/tile/kernel/vmlinux.lds.S | 1 |
4 files changed, 477 insertions, 0 deletions
diff --git a/arch/tile/kernel/Makefile b/arch/tile/kernel/Makefile index c4a957a..2e6eaa1 100644 --- a/arch/tile/kernel/Makefile +++ b/arch/tile/kernel/Makefile @@ -9,6 +9,11 @@ obj-y := backtrace.o entry.o hvglue.o irq.o messaging.o \ sysfs.o time.o traps.o unaligned.o vdso.o \ intvec_$(BITS).o regs_$(BITS).o tile-desc_$(BITS).o +ifdef CONFIG_FUNCTION_TRACER +CFLAGS_REMOVE_ftrace.o = -pg +CFLAGS_REMOVE_early_printk.o = -pg +endif + obj-$(CONFIG_HARDWALL) += hardwall.o obj-$(CONFIG_COMPAT) += compat.o compat_signal.o obj-$(CONFIG_SMP) += smpboot.o smp.o tlb.o @@ -22,5 +27,6 @@ obj-$(CONFIG_PCI) += pci.o endif obj-$(CONFIG_TILE_USB) += usb.o obj-$(CONFIG_TILE_HVGLUE_TRACE) += hvglue_trace.o +obj-$(CONFIG_FUNCTION_TRACER) += ftrace.o mcount_64.o obj-y += vdso/ diff --git a/arch/tile/kernel/ftrace.c b/arch/tile/kernel/ftrace.c new file mode 100644 index 0000000..f1c4520 --- /dev/null +++ b/arch/tile/kernel/ftrace.c @@ -0,0 +1,246 @@ +/* + * Copyright 2012 Tilera Corporation. All Rights Reserved. + * + * 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, version 2. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or + * NON INFRINGEMENT. See the GNU General Public License for + * more details. + * + * TILE-Gx specific ftrace support + */ + +#include <linux/ftrace.h> +#include <linux/uaccess.h> + +#include <asm/cacheflush.h> +#include <asm/ftrace.h> +#include <asm/sections.h> + +#include <arch/opcode.h> + +#ifdef CONFIG_DYNAMIC_FTRACE + +static inline tilegx_bundle_bits NOP(void) +{ + return create_UnaryOpcodeExtension_X0(FNOP_UNARY_OPCODE_X0) | + create_RRROpcodeExtension_X0(UNARY_RRR_0_OPCODE_X0) | + create_Opcode_X0(RRR_0_OPCODE_X0) | + create_UnaryOpcodeExtension_X1(NOP_UNARY_OPCODE_X1) | + create_RRROpcodeExtension_X1(UNARY_RRR_0_OPCODE_X1) | + create_Opcode_X1(RRR_0_OPCODE_X1); +} + +static int machine_stopped __read_mostly; + +int ftrace_arch_code_modify_prepare(void) +{ + machine_stopped = 1; + return 0; +} + +int ftrace_arch_code_modify_post_process(void) +{ + flush_icache_range(0, CHIP_L1I_CACHE_SIZE()); + machine_stopped = 0; + return 0; +} + +/* + * Put { move r10, lr; jal ftrace_caller } in a bundle, this lets dynamic + * tracer just add one cycle overhead to every kernel function when disabled. + */ +static unsigned long ftrace_gen_branch(unsigned long pc, unsigned long addr, + bool link) +{ + tilegx_bundle_bits opcode_x0, opcode_x1; + long pcrel_by_instr = (addr - pc) >> TILEGX_LOG2_BUNDLE_SIZE_IN_BYTES; + + if (link) { + /* opcode: jal addr */ + opcode_x1 = + create_Opcode_X1(JUMP_OPCODE_X1) | + create_JumpOpcodeExtension_X1(JAL_JUMP_OPCODE_X1) | + create_JumpOff_X1(pcrel_by_instr); + } else { + /* opcode: j addr */ + opcode_x1 = + create_Opcode_X1(JUMP_OPCODE_X1) | + create_JumpOpcodeExtension_X1(J_JUMP_OPCODE_X1) | + create_JumpOff_X1(pcrel_by_instr); + } + + if (addr == FTRACE_ADDR) { + /* opcode: or r10, lr, zero */ + opcode_x0 = + create_Dest_X0(10) | + create_SrcA_X0(TREG_LR) | + create_SrcB_X0(TREG_ZERO) | + create_RRROpcodeExtension_X0(OR_RRR_0_OPCODE_X0) | + create_Opcode_X0(RRR_0_OPCODE_X0); + } else { + /* opcode: fnop */ + opcode_x0 = + create_UnaryOpcodeExtension_X0(FNOP_UNARY_OPCODE_X0) | + create_RRROpcodeExtension_X0(UNARY_RRR_0_OPCODE_X0) | + create_Opcode_X0(RRR_0_OPCODE_X0); + } + + return opcode_x1 | opcode_x0; +} + +static unsigned long ftrace_nop_replace(struct dyn_ftrace *rec) +{ + return NOP(); +} + +static unsigned long ftrace_call_replace(unsigned long pc, unsigned long addr) +{ + return ftrace_gen_branch(pc, addr, true); +} + +static int ftrace_modify_code(unsigned long pc, unsigned long old, + unsigned long new) +{ + unsigned long pc_wr; + + /* Check if the address is in kernel text space and module space. */ + if (!kernel_text_address(pc)) + return -EINVAL; + + /* Operate on writable kernel text mapping. */ + pc_wr = pc - MEM_SV_START + PAGE_OFFSET; + + if (probe_kernel_write((void *)pc_wr, &new, MCOUNT_INSN_SIZE)) + return -EPERM; + + smp_wmb(); + + if (!machine_stopped && num_online_cpus() > 1) + flush_icache_range(pc, pc + MCOUNT_INSN_SIZE); + + return 0; +} + +int ftrace_update_ftrace_func(ftrace_func_t func) +{ + unsigned long pc, old; + unsigned long new; + int ret; + + 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_call(struct dyn_ftrace *rec, unsigned long addr) +{ + unsigned long new, old; + unsigned long ip = rec->ip; + + old = ftrace_nop_replace(rec); + new = ftrace_call_replace(ip, addr); + + return ftrace_modify_code(rec->ip, old, new); +} + +int ftrace_make_nop(struct module *mod, + struct dyn_ftrace *rec, unsigned long addr) +{ + unsigned long ip = rec->ip; + unsigned long old; + unsigned long new; + int ret; + + old = ftrace_call_replace(ip, addr); + new = ftrace_nop_replace(rec); + ret = ftrace_modify_code(ip, old, new); + + return ret; +} + +int __init ftrace_dyn_arch_init(void *data) +{ + *(unsigned long *)data = 0; + + return 0; +} +#endif /* CONFIG_DYNAMIC_FTRACE */ + +#ifdef CONFIG_FUNCTION_GRAPH_TRACER +void prepare_ftrace_return(unsigned long *parent, unsigned long self_addr, + unsigned long frame_pointer) +{ + unsigned long return_hooker = (unsigned long) &return_to_handler; + struct ftrace_graph_ent trace; + unsigned long old; + int err; + + if (unlikely(atomic_read(¤t->tracing_graph_pause))) + return; + + old = *parent; + *parent = return_hooker; + + err = ftrace_push_return_trace(old, self_addr, &trace.depth, + frame_pointer); + if (err == -EBUSY) { + *parent = old; + return; + } + + trace.func = self_addr; + + /* Only trace if the calling function expects to */ + if (!ftrace_graph_entry(&trace)) { + current->curr_ret_stack--; + *parent = old; + } +} + +#ifdef CONFIG_DYNAMIC_FTRACE +extern unsigned long ftrace_graph_call; + +static int __ftrace_modify_caller(unsigned long *callsite, + void (*func) (void), bool enable) +{ + unsigned long caller_fn = (unsigned long) func; + unsigned long pc = (unsigned long) callsite; + unsigned long branch = ftrace_gen_branch(pc, caller_fn, false); + unsigned long nop = NOP(); + unsigned long old = enable ? nop : branch; + unsigned long new = enable ? branch : nop; + + return ftrace_modify_code(pc, old, new); +} + +static int ftrace_modify_graph_caller(bool enable) +{ + int ret; + + ret = __ftrace_modify_caller(&ftrace_graph_call, + ftrace_graph_caller, + enable); + + return ret; +} + +int ftrace_enable_ftrace_graph_caller(void) +{ + return ftrace_modify_graph_caller(true); +} + +int ftrace_disable_ftrace_graph_caller(void) +{ + return ftrace_modify_graph_caller(false); +} +#endif /* CONFIG_DYNAMIC_FTRACE */ +#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ diff --git a/arch/tile/kernel/mcount_64.S b/arch/tile/kernel/mcount_64.S new file mode 100644 index 0000000..70d7bb0 --- /dev/null +++ b/arch/tile/kernel/mcount_64.S @@ -0,0 +1,224 @@ +/* + * Copyright 2012 Tilera Corporation. All Rights Reserved. + * + * 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, version 2. + * + * This program is distributed in the hope that it will be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or + * NON INFRINGEMENT. See the GNU General Public License for + * more details. + * + * TILE-Gx specific __mcount support + */ + +#include <linux/linkage.h> +#include <asm/ftrace.h> + +#define REGSIZE 8 + + .text + .global __mcount + + .macro MCOUNT_SAVE_REGS + addli sp, sp, -REGSIZE + { + st sp, lr + addli r29, sp, - (12 * REGSIZE) + } + { + addli sp, sp, - (13 * REGSIZE) + st r29, sp + } + addli r29, r29, REGSIZE + { st r29, r0; addli r29, r29, REGSIZE } + { st r29, r1; addli r29, r29, REGSIZE } + { st r29, r2; addli r29, r29, REGSIZE } + { st r29, r3; addli r29, r29, REGSIZE } + { st r29, r4; addli r29, r29, REGSIZE } + { st r29, r5; addli r29, r29, REGSIZE } + { st r29, r6; addli r29, r29, REGSIZE } + { st r29, r7; addli r29, r29, REGSIZE } + { st r29, r8; addli r29, r29, REGSIZE } + { st r29, r9; addli r29, r29, REGSIZE } + { st r29, r10; addli r29, r29, REGSIZE } + .endm + + .macro MCOUNT_RESTORE_REGS + addli r29, sp, (2 * REGSIZE) + { ld r0, r29; addli r29, r29, REGSIZE } + { ld r1, r29; addli r29, r29, REGSIZE } + { ld r2, r29; addli r29, r29, REGSIZE } + { ld r3, r29; addli r29, r29, REGSIZE } + { ld r4, r29; addli r29, r29, REGSIZE } + { ld r5, r29; addli r29, r29, REGSIZE } + { ld r6, r29; addli r29, r29, REGSIZE } + { ld r7, r29; addli r29, r29, REGSIZE } + { ld r8, r29; addli r29, r29, REGSIZE } + { ld r9, r29; addli r29, r29, REGSIZE } + { ld r10, r29; addli lr, sp, (13 * REGSIZE) } + { ld lr, lr; addli sp, sp, (14 * REGSIZE) } + .endm + + .macro RETURN_BACK + { move r12, lr; move lr, r10 } + jrp r12 + .endm + +#ifdef CONFIG_DYNAMIC_FTRACE + + .align 64 +STD_ENTRY(__mcount) +__mcount: + j ftrace_stub +STD_ENDPROC(__mcount) + + .align 64 +STD_ENTRY(ftrace_caller) + moveli r11, hw2_last(function_trace_stop) + { shl16insli r11, r11, hw1(function_trace_stop); move r12, lr } + { shl16insli r11, r11, hw0(function_trace_stop); move lr, r10 } + ld r11, r11 + beqz r11, 1f + jrp r12 + +1: + { move r10, lr; move lr, r12 } + MCOUNT_SAVE_REGS + + /* arg1: self return address */ + /* arg2: parent's return address */ + { move r0, lr; move r1, r10 } + + .global ftrace_call +ftrace_call: + /* + * a placeholder for the call to a real tracing function, i.e. + * ftrace_trace_function() + */ + nop + +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + .global ftrace_graph_call +ftrace_graph_call: + /* + * a placeholder for the call to a real tracing function, i.e. + * ftrace_graph_caller() + */ + nop +#endif + MCOUNT_RESTORE_REGS + .global ftrace_stub +ftrace_stub: + RETURN_BACK +STD_ENDPROC(ftrace_caller) + +#else /* ! CONFIG_DYNAMIC_FTRACE */ + + .align 64 +STD_ENTRY(__mcount) + moveli r11, hw2_last(function_trace_stop) + { shl16insli r11, r11, hw1(function_trace_stop); move r12, lr } + { shl16insli r11, r11, hw0(function_trace_stop); move lr, r10 } + ld r11, r11 + beqz r11, 1f + jrp r12 + +1: + { move r10, lr; move lr, r12 } + { + moveli r11, hw2_last(ftrace_trace_function) + moveli r13, hw2_last(ftrace_stub) + } + { + shl16insli r11, r11, hw1(ftrace_trace_function) + shl16insli r13, r13, hw1(ftrace_stub) + } + { + shl16insli r11, r11, hw0(ftrace_trace_function) + shl16insli r13, r13, hw0(ftrace_stub) + } + + ld r11, r11 + sub r14, r13, r11 + bnez r14, static_trace + +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + moveli r15, hw2_last(ftrace_graph_return) + shl16insli r15, r15, hw1(ftrace_graph_return) + shl16insli r15, r15, hw0(ftrace_graph_return) + ld r15, r15 + sub r15, r15, r13 + bnez r15, ftrace_graph_caller + + { + moveli r16, hw2_last(ftrace_graph_entry) + moveli r17, hw2_last(ftrace_graph_entry_stub) + } + { + shl16insli r16, r16, hw1(ftrace_graph_entry) + shl16insli r17, r17, hw1(ftrace_graph_entry_stub) + } + { + shl16insli r16, r16, hw0(ftrace_graph_entry) + shl16insli r17, r17, hw0(ftrace_graph_entry_stub) + } + ld r16, r16 + sub r17, r16, r17 + bnez r17, ftrace_graph_caller + +#endif + RETURN_BACK + +static_trace: + MCOUNT_SAVE_REGS + + /* arg1: self return address */ + /* arg2: parent's return address */ + { move r0, lr; move r1, r10 } + + /* call ftrace_trace_function() */ + jalr r11 + + MCOUNT_RESTORE_REGS + + .global ftrace_stub +ftrace_stub: + RETURN_BACK +STD_ENDPROC(__mcount) + +#endif /* ! CONFIG_DYNAMIC_FTRACE */ + +#ifdef CONFIG_FUNCTION_GRAPH_TRACER + +STD_ENTRY(ftrace_graph_caller) +ftrace_graph_caller: +#ifndef CONFIG_DYNAMIC_FTRACE + MCOUNT_SAVE_REGS +#endif + + /* arg1: Get the location of the parent's return address */ + addi r0, sp, 12 * REGSIZE + /* arg2: Get self return address */ + move r1, lr + + jal prepare_ftrace_return + + MCOUNT_RESTORE_REGS + RETURN_BACK +STD_ENDPROC(ftrace_graph_caller) + + .global return_to_handler +return_to_handler: + MCOUNT_SAVE_REGS + + jal ftrace_return_to_handler + /* restore the real parent address */ + move r11, r0 + + MCOUNT_RESTORE_REGS + jr r11 + +#endif /* CONFIG_FUNCTION_GRAPH_TRACER */ diff --git a/arch/tile/kernel/vmlinux.lds.S b/arch/tile/kernel/vmlinux.lds.S index 0f0edaf..673d00a 100644 --- a/arch/tile/kernel/vmlinux.lds.S +++ b/arch/tile/kernel/vmlinux.lds.S @@ -43,6 +43,7 @@ SECTIONS HEAD_TEXT SCHED_TEXT LOCK_TEXT + IRQENTRY_TEXT __fix_text_end = .; /* tile-cpack won't rearrange before this */ TEXT_TEXT *(.text.*) |