hwpmc_x86.c revision 230636
1147191Sjkoshy/*- 2183033Sjkoshy * Copyright (c) 2005,2008 Joseph Koshy 3174395Sjkoshy * Copyright (c) 2007 The FreeBSD Foundation 4147191Sjkoshy * All rights reserved. 5147191Sjkoshy * 6174395Sjkoshy * Portions of this software were developed by A. Joseph Koshy under 7174395Sjkoshy * sponsorship from the FreeBSD Foundation and Google, Inc. 8174395Sjkoshy * 9147191Sjkoshy * Redistribution and use in source and binary forms, with or without 10147191Sjkoshy * modification, are permitted provided that the following conditions 11147191Sjkoshy * are met: 12147191Sjkoshy * 1. Redistributions of source code must retain the above copyright 13147191Sjkoshy * notice, this list of conditions and the following disclaimer. 14147191Sjkoshy * 2. Redistributions in binary form must reproduce the above copyright 15147191Sjkoshy * notice, this list of conditions and the following disclaimer in the 16147191Sjkoshy * documentation and/or other materials provided with the distribution. 17147191Sjkoshy * 18147191Sjkoshy * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 19147191Sjkoshy * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20147191Sjkoshy * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21147191Sjkoshy * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 22147191Sjkoshy * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23147191Sjkoshy * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24147191Sjkoshy * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25147191Sjkoshy * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26147191Sjkoshy * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27147191Sjkoshy * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28147191Sjkoshy * SUCH DAMAGE. 29147191Sjkoshy */ 30147191Sjkoshy 31147191Sjkoshy#include <sys/cdefs.h> 32147191Sjkoshy__FBSDID("$FreeBSD: head/sys/dev/hwpmc/hwpmc_x86.c 230636 2012-01-28 01:38:48Z emaste $"); 33147191Sjkoshy 34147191Sjkoshy#include <sys/param.h> 35147191Sjkoshy#include <sys/bus.h> 36147191Sjkoshy#include <sys/pmc.h> 37174395Sjkoshy#include <sys/proc.h> 38147191Sjkoshy#include <sys/systm.h> 39147191Sjkoshy 40174395Sjkoshy#include <machine/cpu.h> 41185341Sjkim#include <machine/cputypes.h> 42196224Sjhb#include <machine/intr_machdep.h> 43196224Sjhb#include <machine/apicvar.h> 44147191Sjkoshy#include <machine/pmc_mdep.h> 45147191Sjkoshy#include <machine/md_var.h> 46147191Sjkoshy 47174395Sjkoshy#include <vm/vm.h> 48174395Sjkoshy#include <vm/vm_param.h> 49174395Sjkoshy#include <vm/pmap.h> 50174395Sjkoshy 51174395Sjkoshy/* 52174395Sjkoshy * Attempt to walk a user call stack using a too-simple algorithm. 53174395Sjkoshy * In the general case we need unwind information associated with 54174395Sjkoshy * the executable to be able to walk the user stack. 55174395Sjkoshy * 56174395Sjkoshy * We are handed a trap frame laid down at the time the PMC interrupt 57174395Sjkoshy * was taken. If the application is using frame pointers, the saved 58174395Sjkoshy * PC value could be: 59174395Sjkoshy * a. at the beginning of a function before the stack frame is laid 60174395Sjkoshy * down, 61174395Sjkoshy * b. just before a 'ret', after the stack frame has been taken off, 62174395Sjkoshy * c. somewhere else in the function with a valid stack frame being 63174395Sjkoshy * present, 64174395Sjkoshy * 65174395Sjkoshy * If the application is not using frame pointers, this algorithm will 66174395Sjkoshy * fail to yield an interesting call chain. 67174395Sjkoshy * 68174395Sjkoshy * TODO: figure out a way to use unwind information. 69174395Sjkoshy */ 70147191Sjkoshy 71174395Sjkoshyint 72174395Sjkoshypmc_save_user_callchain(uintptr_t *cc, int nframes, struct trapframe *tf) 73174395Sjkoshy{ 74174395Sjkoshy int n; 75174395Sjkoshy uint32_t instr; 76174395Sjkoshy uintptr_t fp, oldfp, pc, r, sp; 77174395Sjkoshy 78174395Sjkoshy KASSERT(TRAPF_USERMODE(tf), ("[x86,%d] Not a user trap frame tf=%p", 79174395Sjkoshy __LINE__, (void *) tf)); 80174395Sjkoshy 81174395Sjkoshy pc = PMC_TRAPFRAME_TO_PC(tf); 82174395Sjkoshy oldfp = fp = PMC_TRAPFRAME_TO_FP(tf); 83183033Sjkoshy sp = PMC_TRAPFRAME_TO_USER_SP(tf); 84174395Sjkoshy 85174395Sjkoshy *cc++ = pc; n = 1; 86174395Sjkoshy 87174395Sjkoshy r = fp + sizeof(uintptr_t); /* points to return address */ 88174395Sjkoshy 89174395Sjkoshy if (!PMC_IN_USERSPACE(pc)) 90174395Sjkoshy return (n); 91174395Sjkoshy 92174395Sjkoshy if (copyin((void *) pc, &instr, sizeof(instr)) != 0) 93174395Sjkoshy return (n); 94174395Sjkoshy 95174395Sjkoshy if (PMC_AT_FUNCTION_PROLOGUE_PUSH_BP(instr) || 96174395Sjkoshy PMC_AT_FUNCTION_EPILOGUE_RET(instr)) { /* ret */ 97174395Sjkoshy if (copyin((void *) sp, &pc, sizeof(pc)) != 0) 98174395Sjkoshy return (n); 99174395Sjkoshy } else if (PMC_AT_FUNCTION_PROLOGUE_MOV_SP_BP(instr)) { 100174395Sjkoshy sp += sizeof(uintptr_t); 101174395Sjkoshy if (copyin((void *) sp, &pc, sizeof(pc)) != 0) 102174395Sjkoshy return (n); 103174395Sjkoshy } else if (copyin((void *) r, &pc, sizeof(pc)) != 0 || 104200001Semaste copyin((void *) fp, &fp, sizeof(fp)) != 0) 105174395Sjkoshy return (n); 106174395Sjkoshy 107174395Sjkoshy for (; n < nframes;) { 108174395Sjkoshy if (pc == 0 || !PMC_IN_USERSPACE(pc)) 109174395Sjkoshy break; 110174395Sjkoshy 111174395Sjkoshy *cc++ = pc; n++; 112174395Sjkoshy 113174395Sjkoshy if (fp < oldfp) 114174395Sjkoshy break; 115174395Sjkoshy 116174395Sjkoshy r = fp + sizeof(uintptr_t); /* address of return address */ 117174395Sjkoshy oldfp = fp; 118174395Sjkoshy 119174395Sjkoshy if (copyin((void *) r, &pc, sizeof(pc)) != 0 || 120174395Sjkoshy copyin((void *) fp, &fp, sizeof(fp)) != 0) 121174395Sjkoshy break; 122174395Sjkoshy } 123174395Sjkoshy 124174395Sjkoshy return (n); 125174395Sjkoshy} 126174395Sjkoshy 127174395Sjkoshy/* 128174395Sjkoshy * Walking the kernel call stack. 129174395Sjkoshy * 130174395Sjkoshy * We are handed the trap frame laid down at the time the PMC 131174395Sjkoshy * interrupt was taken. The saved PC could be: 132174395Sjkoshy * a. in the lowlevel trap handler, meaning that there isn't a C stack 133174395Sjkoshy * to traverse, 134174395Sjkoshy * b. at the beginning of a function before the stack frame is laid 135174395Sjkoshy * down, 136174395Sjkoshy * c. just before a 'ret', after the stack frame has been taken off, 137174395Sjkoshy * d. somewhere else in a function with a valid stack frame being 138174395Sjkoshy * present. 139174395Sjkoshy * 140174395Sjkoshy * In case (d), the previous frame pointer is at [%ebp]/[%rbp] and 141174395Sjkoshy * the return address is at [%ebp+4]/[%rbp+8]. 142174395Sjkoshy * 143174395Sjkoshy * For cases (b) and (c), the return address is at [%esp]/[%rsp] and 144174395Sjkoshy * the frame pointer doesn't need to be changed when going up one 145174395Sjkoshy * level in the stack. 146174395Sjkoshy * 147174395Sjkoshy * For case (a), we check if the PC lies in low-level trap handling 148174395Sjkoshy * code, and if so we terminate our trace. 149174395Sjkoshy */ 150174395Sjkoshy 151174395Sjkoshyint 152174395Sjkoshypmc_save_kernel_callchain(uintptr_t *cc, int nframes, struct trapframe *tf) 153174395Sjkoshy{ 154174395Sjkoshy int n; 155174395Sjkoshy uint32_t instr; 156174395Sjkoshy uintptr_t fp, pc, r, sp, stackstart, stackend; 157174395Sjkoshy struct thread *td; 158174395Sjkoshy 159174395Sjkoshy KASSERT(TRAPF_USERMODE(tf) == 0,("[x86,%d] not a kernel backtrace", 160174395Sjkoshy __LINE__)); 161174395Sjkoshy 162174395Sjkoshy pc = PMC_TRAPFRAME_TO_PC(tf); 163174395Sjkoshy fp = PMC_TRAPFRAME_TO_FP(tf); 164183033Sjkoshy sp = PMC_TRAPFRAME_TO_KERNEL_SP(tf); 165174395Sjkoshy 166174395Sjkoshy *cc++ = pc; 167174395Sjkoshy r = fp + sizeof(uintptr_t); /* points to return address */ 168174395Sjkoshy 169174395Sjkoshy if ((td = curthread) == NULL) 170174395Sjkoshy return (1); 171174395Sjkoshy 172174395Sjkoshy if (nframes <= 1) 173174395Sjkoshy return (1); 174174395Sjkoshy 175174395Sjkoshy stackstart = (uintptr_t) td->td_kstack; 176174395Sjkoshy stackend = (uintptr_t) td->td_kstack + td->td_kstack_pages * PAGE_SIZE; 177174395Sjkoshy 178174395Sjkoshy if (PMC_IN_TRAP_HANDLER(pc) || 179200060Sjkoshy !PMC_IN_KERNEL(pc) || 180200060Sjkoshy !PMC_IN_KERNEL_STACK(r, stackstart, stackend) || 181174395Sjkoshy !PMC_IN_KERNEL_STACK(sp, stackstart, stackend) || 182174395Sjkoshy !PMC_IN_KERNEL_STACK(fp, stackstart, stackend)) 183174395Sjkoshy return (1); 184174395Sjkoshy 185174395Sjkoshy instr = *(uint32_t *) pc; 186174395Sjkoshy 187174395Sjkoshy /* 188174395Sjkoshy * Determine whether the interrupted function was in the 189174395Sjkoshy * processing of either laying down its stack frame or taking 190174395Sjkoshy * it off. 191174395Sjkoshy * 192174395Sjkoshy * If we haven't started laying down a stack frame, or are 193174395Sjkoshy * just about to return, then our caller's address is at 194174395Sjkoshy * *sp, and we don't have a frame to unwind. 195174395Sjkoshy */ 196174395Sjkoshy if (PMC_AT_FUNCTION_PROLOGUE_PUSH_BP(instr) || 197174395Sjkoshy PMC_AT_FUNCTION_EPILOGUE_RET(instr)) 198174395Sjkoshy pc = *(uintptr_t *) sp; 199174395Sjkoshy else if (PMC_AT_FUNCTION_PROLOGUE_MOV_SP_BP(instr)) { 200174395Sjkoshy /* 201174395Sjkoshy * The code was midway through laying down a frame. 202174395Sjkoshy * At this point sp[0] has a frame back pointer, 203174395Sjkoshy * and the caller's address is therefore at sp[1]. 204174395Sjkoshy */ 205174395Sjkoshy sp += sizeof(uintptr_t); 206174395Sjkoshy if (!PMC_IN_KERNEL_STACK(sp, stackstart, stackend)) 207174395Sjkoshy return (1); 208174395Sjkoshy pc = *(uintptr_t *) sp; 209174395Sjkoshy } else { 210174395Sjkoshy /* 211174395Sjkoshy * Not in the function prologue or epilogue. 212174395Sjkoshy */ 213174395Sjkoshy pc = *(uintptr_t *) r; 214174395Sjkoshy fp = *(uintptr_t *) fp; 215174395Sjkoshy } 216174395Sjkoshy 217174395Sjkoshy for (n = 1; n < nframes; n++) { 218174395Sjkoshy *cc++ = pc; 219174395Sjkoshy 220174395Sjkoshy if (PMC_IN_TRAP_HANDLER(pc)) 221174395Sjkoshy break; 222174395Sjkoshy 223174395Sjkoshy r = fp + sizeof(uintptr_t); 224174395Sjkoshy if (!PMC_IN_KERNEL_STACK(fp, stackstart, stackend) || 225200060Sjkoshy !PMC_IN_KERNEL_STACK(r, stackstart, stackend)) 226174395Sjkoshy break; 227174395Sjkoshy pc = *(uintptr_t *) r; 228174395Sjkoshy fp = *(uintptr_t *) fp; 229174395Sjkoshy } 230174395Sjkoshy 231174395Sjkoshy return (n); 232174395Sjkoshy} 233174395Sjkoshy 234147191Sjkoshy/* 235147191Sjkoshy * Machine dependent initialization for x86 class platforms. 236147191Sjkoshy */ 237147191Sjkoshy 238147191Sjkoshystruct pmc_mdep * 239147191Sjkoshypmc_md_initialize() 240147191Sjkoshy{ 241149375Sjkoshy int i; 242149375Sjkoshy struct pmc_mdep *md; 243149375Sjkoshy 244147191Sjkoshy /* determine the CPU kind */ 245185341Sjkim if (cpu_vendor_id == CPU_VENDOR_AMD) 246149375Sjkoshy md = pmc_amd_initialize(); 247185341Sjkim else if (cpu_vendor_id == CPU_VENDOR_INTEL) 248149375Sjkoshy md = pmc_intel_initialize(); 249184802Sjkoshy else 250196224Sjhb return (NULL); 251149375Sjkoshy 252149375Sjkoshy /* disallow sampling if we do not have an LAPIC */ 253230636Semaste if (md != NULL && !lapic_enable_pmc()) 254149375Sjkoshy for (i = 1; i < md->pmd_nclass; i++) 255184802Sjkoshy md->pmd_classdep[i].pcd_caps &= ~PMC_CAP_INTERRUPT; 256149375Sjkoshy 257184802Sjkoshy return (md); 258147191Sjkoshy} 259184802Sjkoshy 260184802Sjkoshyvoid 261184802Sjkoshypmc_md_finalize(struct pmc_mdep *md) 262184802Sjkoshy{ 263196224Sjhb 264196224Sjhb lapic_disable_pmc(); 265185341Sjkim if (cpu_vendor_id == CPU_VENDOR_AMD) 266184802Sjkoshy pmc_amd_finalize(md); 267185341Sjkim else if (cpu_vendor_id == CPU_VENDOR_INTEL) 268184802Sjkoshy pmc_intel_finalize(md); 269184802Sjkoshy else 270184802Sjkoshy KASSERT(0, ("[x86,%d] Unknown vendor", __LINE__)); 271184802Sjkoshy} 272