xref: /freebsd/sys/dev/hwpmc/hwpmc_x86.c (revision f5f9340b9807d44d200658ba1bbbbbb57ab72e07)
1f263522aSJoseph Koshy /*-
2d0d0192fSJoseph Koshy  * Copyright (c) 2005,2008 Joseph Koshy
3d07f36b0SJoseph Koshy  * Copyright (c) 2007 The FreeBSD Foundation
4f263522aSJoseph Koshy  * All rights reserved.
5f263522aSJoseph Koshy  *
6d07f36b0SJoseph Koshy  * Portions of this software were developed by A. Joseph Koshy under
7d07f36b0SJoseph Koshy  * sponsorship from the FreeBSD Foundation and Google, Inc.
8d07f36b0SJoseph Koshy  *
9f263522aSJoseph Koshy  * Redistribution and use in source and binary forms, with or without
10f263522aSJoseph Koshy  * modification, are permitted provided that the following conditions
11f263522aSJoseph Koshy  * are met:
12f263522aSJoseph Koshy  * 1. Redistributions of source code must retain the above copyright
13f263522aSJoseph Koshy  *    notice, this list of conditions and the following disclaimer.
14f263522aSJoseph Koshy  * 2. Redistributions in binary form must reproduce the above copyright
15f263522aSJoseph Koshy  *    notice, this list of conditions and the following disclaimer in the
16f263522aSJoseph Koshy  *    documentation and/or other materials provided with the distribution.
17f263522aSJoseph Koshy  *
18f263522aSJoseph Koshy  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
19f263522aSJoseph Koshy  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20f263522aSJoseph Koshy  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21f263522aSJoseph Koshy  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
22f263522aSJoseph Koshy  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23f263522aSJoseph Koshy  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24f263522aSJoseph Koshy  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25f263522aSJoseph Koshy  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26f263522aSJoseph Koshy  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27f263522aSJoseph Koshy  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28f263522aSJoseph Koshy  * SUCH DAMAGE.
29f263522aSJoseph Koshy  */
30f263522aSJoseph Koshy 
31f263522aSJoseph Koshy #include <sys/cdefs.h>
32f263522aSJoseph Koshy __FBSDID("$FreeBSD$");
33f263522aSJoseph Koshy 
34f263522aSJoseph Koshy #include <sys/param.h>
35f263522aSJoseph Koshy #include <sys/bus.h>
36f263522aSJoseph Koshy #include <sys/pmc.h>
37d07f36b0SJoseph Koshy #include <sys/proc.h>
38f263522aSJoseph Koshy #include <sys/systm.h>
39f263522aSJoseph Koshy 
40d07f36b0SJoseph Koshy #include <machine/cpu.h>
415113aa0aSJung-uk Kim #include <machine/cputypes.h>
4221157ad3SJohn Baldwin #include <machine/intr_machdep.h>
4321157ad3SJohn Baldwin #include <machine/apicvar.h>
44f263522aSJoseph Koshy #include <machine/pmc_mdep.h>
45f263522aSJoseph Koshy #include <machine/md_var.h>
46f263522aSJoseph Koshy 
47d07f36b0SJoseph Koshy #include <vm/vm.h>
48d07f36b0SJoseph Koshy #include <vm/vm_param.h>
49d07f36b0SJoseph Koshy #include <vm/pmap.h>
50d07f36b0SJoseph Koshy 
51*f5f9340bSFabien Thomas #include "hwpmc_soft.h"
52*f5f9340bSFabien Thomas 
53d07f36b0SJoseph Koshy /*
54d07f36b0SJoseph Koshy  * Attempt to walk a user call stack using a too-simple algorithm.
55d07f36b0SJoseph Koshy  * In the general case we need unwind information associated with
56d07f36b0SJoseph Koshy  * the executable to be able to walk the user stack.
57d07f36b0SJoseph Koshy  *
58d07f36b0SJoseph Koshy  * We are handed a trap frame laid down at the time the PMC interrupt
59d07f36b0SJoseph Koshy  * was taken.  If the application is using frame pointers, the saved
60d07f36b0SJoseph Koshy  * PC value could be:
61d07f36b0SJoseph Koshy  * a. at the beginning of a function before the stack frame is laid
62d07f36b0SJoseph Koshy  *    down,
63d07f36b0SJoseph Koshy  * b. just before a 'ret', after the stack frame has been taken off,
64d07f36b0SJoseph Koshy  * c. somewhere else in the function with a valid stack frame being
65d07f36b0SJoseph Koshy  *    present,
66d07f36b0SJoseph Koshy  *
67d07f36b0SJoseph Koshy  * If the application is not using frame pointers, this algorithm will
68d07f36b0SJoseph Koshy  * fail to yield an interesting call chain.
69d07f36b0SJoseph Koshy  *
70d07f36b0SJoseph Koshy  * TODO: figure out a way to use unwind information.
71d07f36b0SJoseph Koshy  */
72d07f36b0SJoseph Koshy 
73d07f36b0SJoseph Koshy int
74d07f36b0SJoseph Koshy pmc_save_user_callchain(uintptr_t *cc, int nframes, struct trapframe *tf)
75d07f36b0SJoseph Koshy {
76d07f36b0SJoseph Koshy 	int n;
77d07f36b0SJoseph Koshy 	uint32_t instr;
78d07f36b0SJoseph Koshy 	uintptr_t fp, oldfp, pc, r, sp;
79d07f36b0SJoseph Koshy 
80d07f36b0SJoseph Koshy 	KASSERT(TRAPF_USERMODE(tf), ("[x86,%d] Not a user trap frame tf=%p",
81d07f36b0SJoseph Koshy 	    __LINE__, (void *) tf));
82d07f36b0SJoseph Koshy 
83d07f36b0SJoseph Koshy 	pc = PMC_TRAPFRAME_TO_PC(tf);
84d07f36b0SJoseph Koshy 	oldfp = fp = PMC_TRAPFRAME_TO_FP(tf);
85d0d0192fSJoseph Koshy 	sp = PMC_TRAPFRAME_TO_USER_SP(tf);
86d07f36b0SJoseph Koshy 
87d07f36b0SJoseph Koshy 	*cc++ = pc; n = 1;
88d07f36b0SJoseph Koshy 
89d07f36b0SJoseph Koshy 	r = fp + sizeof(uintptr_t); /* points to return address */
90d07f36b0SJoseph Koshy 
91d07f36b0SJoseph Koshy 	if (!PMC_IN_USERSPACE(pc))
92d07f36b0SJoseph Koshy 		return (n);
93d07f36b0SJoseph Koshy 
94d07f36b0SJoseph Koshy 	if (copyin((void *) pc, &instr, sizeof(instr)) != 0)
95d07f36b0SJoseph Koshy 		return (n);
96d07f36b0SJoseph Koshy 
97d07f36b0SJoseph Koshy 	if (PMC_AT_FUNCTION_PROLOGUE_PUSH_BP(instr) ||
98d07f36b0SJoseph Koshy 	    PMC_AT_FUNCTION_EPILOGUE_RET(instr)) { /* ret */
99d07f36b0SJoseph Koshy 		if (copyin((void *) sp, &pc, sizeof(pc)) != 0)
100d07f36b0SJoseph Koshy 			return (n);
101d07f36b0SJoseph Koshy 	} else if (PMC_AT_FUNCTION_PROLOGUE_MOV_SP_BP(instr)) {
102d07f36b0SJoseph Koshy 		sp += sizeof(uintptr_t);
103d07f36b0SJoseph Koshy 		if (copyin((void *) sp, &pc, sizeof(pc)) != 0)
104d07f36b0SJoseph Koshy 			return (n);
105d07f36b0SJoseph Koshy 	} else if (copyin((void *) r, &pc, sizeof(pc)) != 0 ||
1061a12d24bSEd Maste 	    copyin((void *) fp, &fp, sizeof(fp)) != 0)
107d07f36b0SJoseph Koshy 		return (n);
108d07f36b0SJoseph Koshy 
109d07f36b0SJoseph Koshy 	for (; n < nframes;) {
110d07f36b0SJoseph Koshy 		if (pc == 0 || !PMC_IN_USERSPACE(pc))
111d07f36b0SJoseph Koshy 			break;
112d07f36b0SJoseph Koshy 
113d07f36b0SJoseph Koshy 		*cc++ = pc; n++;
114d07f36b0SJoseph Koshy 
115d07f36b0SJoseph Koshy 		if (fp < oldfp)
116d07f36b0SJoseph Koshy 			break;
117d07f36b0SJoseph Koshy 
118d07f36b0SJoseph Koshy 		r = fp + sizeof(uintptr_t); /* address of return address */
119d07f36b0SJoseph Koshy 		oldfp = fp;
120d07f36b0SJoseph Koshy 
121d07f36b0SJoseph Koshy 		if (copyin((void *) r, &pc, sizeof(pc)) != 0 ||
122d07f36b0SJoseph Koshy 		    copyin((void *) fp, &fp, sizeof(fp)) != 0)
123d07f36b0SJoseph Koshy 			break;
124d07f36b0SJoseph Koshy 	}
125d07f36b0SJoseph Koshy 
126d07f36b0SJoseph Koshy 	return (n);
127d07f36b0SJoseph Koshy }
128d07f36b0SJoseph Koshy 
129d07f36b0SJoseph Koshy /*
130d07f36b0SJoseph Koshy  * Walking the kernel call stack.
131d07f36b0SJoseph Koshy  *
132d07f36b0SJoseph Koshy  * We are handed the trap frame laid down at the time the PMC
133d07f36b0SJoseph Koshy  * interrupt was taken.  The saved PC could be:
134d07f36b0SJoseph Koshy  * a. in the lowlevel trap handler, meaning that there isn't a C stack
135d07f36b0SJoseph Koshy  *    to traverse,
136d07f36b0SJoseph Koshy  * b. at the beginning of a function before the stack frame is laid
137d07f36b0SJoseph Koshy  *    down,
138d07f36b0SJoseph Koshy  * c. just before a 'ret', after the stack frame has been taken off,
139d07f36b0SJoseph Koshy  * d. somewhere else in a function with a valid stack frame being
140d07f36b0SJoseph Koshy  *    present.
141d07f36b0SJoseph Koshy  *
142d07f36b0SJoseph Koshy  * In case (d), the previous frame pointer is at [%ebp]/[%rbp] and
143d07f36b0SJoseph Koshy  * the return address is at [%ebp+4]/[%rbp+8].
144d07f36b0SJoseph Koshy  *
145d07f36b0SJoseph Koshy  * For cases (b) and (c), the return address is at [%esp]/[%rsp] and
146d07f36b0SJoseph Koshy  * the frame pointer doesn't need to be changed when going up one
147d07f36b0SJoseph Koshy  * level in the stack.
148d07f36b0SJoseph Koshy  *
149d07f36b0SJoseph Koshy  * For case (a), we check if the PC lies in low-level trap handling
150d07f36b0SJoseph Koshy  * code, and if so we terminate our trace.
151d07f36b0SJoseph Koshy  */
152d07f36b0SJoseph Koshy 
153d07f36b0SJoseph Koshy int
154d07f36b0SJoseph Koshy pmc_save_kernel_callchain(uintptr_t *cc, int nframes, struct trapframe *tf)
155d07f36b0SJoseph Koshy {
156d07f36b0SJoseph Koshy 	int n;
157d07f36b0SJoseph Koshy 	uint32_t instr;
158d07f36b0SJoseph Koshy 	uintptr_t fp, pc, r, sp, stackstart, stackend;
159d07f36b0SJoseph Koshy 	struct thread *td;
160d07f36b0SJoseph Koshy 
161d07f36b0SJoseph Koshy 	KASSERT(TRAPF_USERMODE(tf) == 0,("[x86,%d] not a kernel backtrace",
162d07f36b0SJoseph Koshy 	    __LINE__));
163d07f36b0SJoseph Koshy 
164d07f36b0SJoseph Koshy 	pc = PMC_TRAPFRAME_TO_PC(tf);
165d07f36b0SJoseph Koshy 	fp = PMC_TRAPFRAME_TO_FP(tf);
166d0d0192fSJoseph Koshy 	sp = PMC_TRAPFRAME_TO_KERNEL_SP(tf);
167d07f36b0SJoseph Koshy 
168d07f36b0SJoseph Koshy 	*cc++ = pc;
169d07f36b0SJoseph Koshy 	r = fp + sizeof(uintptr_t); /* points to return address */
170d07f36b0SJoseph Koshy 
171d07f36b0SJoseph Koshy 	if ((td = curthread) == NULL)
172d07f36b0SJoseph Koshy 		return (1);
173d07f36b0SJoseph Koshy 
174d07f36b0SJoseph Koshy 	if (nframes <= 1)
175d07f36b0SJoseph Koshy 		return (1);
176d07f36b0SJoseph Koshy 
177d07f36b0SJoseph Koshy 	stackstart = (uintptr_t) td->td_kstack;
178d07f36b0SJoseph Koshy 	stackend = (uintptr_t) td->td_kstack + td->td_kstack_pages * PAGE_SIZE;
179d07f36b0SJoseph Koshy 
180d07f36b0SJoseph Koshy 	if (PMC_IN_TRAP_HANDLER(pc) ||
181c66e06a2SJoseph Koshy 	    !PMC_IN_KERNEL(pc) ||
182c66e06a2SJoseph Koshy 	    !PMC_IN_KERNEL_STACK(r, stackstart, stackend) ||
183d07f36b0SJoseph Koshy 	    !PMC_IN_KERNEL_STACK(sp, stackstart, stackend) ||
184d07f36b0SJoseph Koshy 	    !PMC_IN_KERNEL_STACK(fp, stackstart, stackend))
185d07f36b0SJoseph Koshy 		return (1);
186d07f36b0SJoseph Koshy 
187d07f36b0SJoseph Koshy 	instr = *(uint32_t *) pc;
188d07f36b0SJoseph Koshy 
189d07f36b0SJoseph Koshy 	/*
190d07f36b0SJoseph Koshy 	 * Determine whether the interrupted function was in the
191d07f36b0SJoseph Koshy 	 * processing of either laying down its stack frame or taking
192d07f36b0SJoseph Koshy 	 * it off.
193d07f36b0SJoseph Koshy 	 *
194d07f36b0SJoseph Koshy 	 * If we haven't started laying down a stack frame, or are
195d07f36b0SJoseph Koshy 	 * just about to return, then our caller's address is at
196d07f36b0SJoseph Koshy 	 * *sp, and we don't have a frame to unwind.
197d07f36b0SJoseph Koshy 	 */
198d07f36b0SJoseph Koshy 	if (PMC_AT_FUNCTION_PROLOGUE_PUSH_BP(instr) ||
199d07f36b0SJoseph Koshy 	    PMC_AT_FUNCTION_EPILOGUE_RET(instr))
200d07f36b0SJoseph Koshy 		pc = *(uintptr_t *) sp;
201d07f36b0SJoseph Koshy 	else if (PMC_AT_FUNCTION_PROLOGUE_MOV_SP_BP(instr)) {
202d07f36b0SJoseph Koshy 		/*
203d07f36b0SJoseph Koshy 		 * The code was midway through laying down a frame.
204d07f36b0SJoseph Koshy 		 * At this point sp[0] has a frame back pointer,
205d07f36b0SJoseph Koshy 		 * and the caller's address is therefore at sp[1].
206d07f36b0SJoseph Koshy 		 */
207d07f36b0SJoseph Koshy 		sp += sizeof(uintptr_t);
208d07f36b0SJoseph Koshy 		if (!PMC_IN_KERNEL_STACK(sp, stackstart, stackend))
209d07f36b0SJoseph Koshy 			return (1);
210d07f36b0SJoseph Koshy 		pc = *(uintptr_t *) sp;
211d07f36b0SJoseph Koshy 	} else {
212d07f36b0SJoseph Koshy 		/*
213d07f36b0SJoseph Koshy 		 * Not in the function prologue or epilogue.
214d07f36b0SJoseph Koshy 		 */
215d07f36b0SJoseph Koshy 		pc = *(uintptr_t *) r;
216d07f36b0SJoseph Koshy 		fp = *(uintptr_t *) fp;
217d07f36b0SJoseph Koshy 	}
218d07f36b0SJoseph Koshy 
219d07f36b0SJoseph Koshy 	for (n = 1; n < nframes; n++) {
220d07f36b0SJoseph Koshy 		*cc++ = pc;
221d07f36b0SJoseph Koshy 
222d07f36b0SJoseph Koshy 		if (PMC_IN_TRAP_HANDLER(pc))
223d07f36b0SJoseph Koshy 			break;
224d07f36b0SJoseph Koshy 
225d07f36b0SJoseph Koshy 		r = fp + sizeof(uintptr_t);
226d07f36b0SJoseph Koshy 		if (!PMC_IN_KERNEL_STACK(fp, stackstart, stackend) ||
227c66e06a2SJoseph Koshy 		    !PMC_IN_KERNEL_STACK(r, stackstart, stackend))
228d07f36b0SJoseph Koshy 			break;
229d07f36b0SJoseph Koshy 		pc = *(uintptr_t *) r;
230d07f36b0SJoseph Koshy 		fp = *(uintptr_t *) fp;
231d07f36b0SJoseph Koshy 	}
232d07f36b0SJoseph Koshy 
233d07f36b0SJoseph Koshy 	return (n);
234d07f36b0SJoseph Koshy }
235f263522aSJoseph Koshy 
236f263522aSJoseph Koshy /*
237f263522aSJoseph Koshy  * Machine dependent initialization for x86 class platforms.
238f263522aSJoseph Koshy  */
239f263522aSJoseph Koshy 
240f263522aSJoseph Koshy struct pmc_mdep *
241f263522aSJoseph Koshy pmc_md_initialize()
242f263522aSJoseph Koshy {
243e753fde4SJoseph Koshy 	int i;
244e753fde4SJoseph Koshy 	struct pmc_mdep *md;
245e753fde4SJoseph Koshy 
246f263522aSJoseph Koshy 	/* determine the CPU kind */
2475113aa0aSJung-uk Kim 	if (cpu_vendor_id == CPU_VENDOR_AMD)
248e753fde4SJoseph Koshy 		md = pmc_amd_initialize();
2495113aa0aSJung-uk Kim 	else if (cpu_vendor_id == CPU_VENDOR_INTEL)
250e753fde4SJoseph Koshy 		md = pmc_intel_initialize();
251e829eb6dSJoseph Koshy 	else
25221157ad3SJohn Baldwin 		return (NULL);
253e753fde4SJoseph Koshy 
254e753fde4SJoseph Koshy 	/* disallow sampling if we do not have an LAPIC */
255158c4475SEd Maste 	if (md != NULL && !lapic_enable_pmc())
256*f5f9340bSFabien Thomas 		for (i = 0; i < md->pmd_nclass; i++) {
257*f5f9340bSFabien Thomas 			if (i == PMC_CLASS_INDEX_SOFT)
258*f5f9340bSFabien Thomas 				continue;
259e829eb6dSJoseph Koshy 			md->pmd_classdep[i].pcd_caps &= ~PMC_CAP_INTERRUPT;
260*f5f9340bSFabien Thomas 		}
261e753fde4SJoseph Koshy 
262e829eb6dSJoseph Koshy 	return (md);
263e829eb6dSJoseph Koshy }
264e829eb6dSJoseph Koshy 
265e829eb6dSJoseph Koshy void
266e829eb6dSJoseph Koshy pmc_md_finalize(struct pmc_mdep *md)
267e829eb6dSJoseph Koshy {
26821157ad3SJohn Baldwin 
26921157ad3SJohn Baldwin 	lapic_disable_pmc();
2705113aa0aSJung-uk Kim 	if (cpu_vendor_id == CPU_VENDOR_AMD)
271e829eb6dSJoseph Koshy 		pmc_amd_finalize(md);
2725113aa0aSJung-uk Kim 	else if (cpu_vendor_id == CPU_VENDOR_INTEL)
273e829eb6dSJoseph Koshy 		pmc_intel_finalize(md);
274e829eb6dSJoseph Koshy 	else
275e829eb6dSJoseph Koshy 		KASSERT(0, ("[x86,%d] Unknown vendor", __LINE__));
276f263522aSJoseph Koshy }
277