Linux-libre 4.6.2-gnu

1 files changed, 0 insertions, 1188 deletions

diff --git a/arch/x86/kernel/cpu/perf_event_intel_pt.c b/arch/x86/kernel/cpu/perf_event_intel_pt.c
deleted file mode 100644
index c0bbd1033..000000000
--- a/arch/x86/kernel/cpu/perf_event_intel_pt.c
+++ /dev/null
@@ -1,1188 +0,0 @@
-/*
- * Intel(R) Processor Trace PMU driver for perf
- * Copyright (c) 2013-2014, Intel Corporation.
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms and conditions of the GNU General Public License,
- * version 2, as published by the Free Software Foundation.
- *
- * This program is distributed in the hope it will be useful, but WITHOUT
- * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
- * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
- * more details.
- *
- * Intel PT is specified in the Intel Architecture Instruction Set Extensions
- * Programming Reference:
- * http://software.intel.com/en-us/intel-isa-extensions
- */
-
-#undef DEBUG
-
-#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
-
-#include <linux/types.h>
-#include <linux/slab.h>
-#include <linux/device.h>
-
-#include <asm/perf_event.h>
-#include <asm/insn.h>
-#include <asm/io.h>
-#include <asm/intel_pt.h>
-
-#include "perf_event.h"
-#include "intel_pt.h"
-
-static DEFINE_PER_CPU(struct pt, pt_ctx);
-
-static struct pt_pmu pt_pmu;
-
-enum cpuid_regs {
-	CR_EAX = 0,
-	CR_ECX,
-	CR_EDX,
-	CR_EBX
-};
-
-/*
- * Capabilities of Intel PT hardware, such as number of address bits or
- * supported output schemes, are cached and exported to userspace as "caps"
- * attribute group of pt pmu device
- * (/sys/bus/event_source/devices/intel_pt/caps/) so that userspace can store
- * relevant bits together with intel_pt traces.
- *
- * These are necessary for both trace decoding (payloads_lip, contains address
- * width encoded in IP-related packets), and event configuration (bitmasks with
- * permitted values for certain bit fields).
- */
-#define PT_CAP(_n, _l, _r, _m)						\
-	[PT_CAP_ ## _n] = { .name = __stringify(_n), .leaf = _l,	\
-			    .reg = _r, .mask = _m }
-
-static struct pt_cap_desc {
-	const char	*name;
-	u32		leaf;
-	u8		reg;
-	u32		mask;
-} pt_caps[] = {
-	PT_CAP(max_subleaf,		0, CR_EAX, 0xffffffff),
-	PT_CAP(cr3_filtering,		0, CR_EBX, BIT(0)),
-	PT_CAP(psb_cyc,			0, CR_EBX, BIT(1)),
-	PT_CAP(mtc,			0, CR_EBX, BIT(3)),
-	PT_CAP(topa_output,		0, CR_ECX, BIT(0)),
-	PT_CAP(topa_multiple_entries,	0, CR_ECX, BIT(1)),
-	PT_CAP(single_range_output,	0, CR_ECX, BIT(2)),
-	PT_CAP(payloads_lip,		0, CR_ECX, BIT(31)),
-	PT_CAP(mtc_periods,		1, CR_EAX, 0xffff0000),
-	PT_CAP(cycle_thresholds,	1, CR_EBX, 0xffff),
-	PT_CAP(psb_periods,		1, CR_EBX, 0xffff0000),
-};
-
-static u32 pt_cap_get(enum pt_capabilities cap)
-{
-	struct pt_cap_desc *cd = &pt_caps[cap];
-	u32 c = pt_pmu.caps[cd->leaf * PT_CPUID_REGS_NUM + cd->reg];
-	unsigned int shift = __ffs(cd->mask);
-
-	return (c & cd->mask) >> shift;
-}
-
-static ssize_t pt_cap_show(struct device *cdev,
-			   struct device_attribute *attr,
-			   char *buf)
-{
-	struct dev_ext_attribute *ea =
-		container_of(attr, struct dev_ext_attribute, attr);
-	enum pt_capabilities cap = (long)ea->var;
-
-	return snprintf(buf, PAGE_SIZE, "%x\n", pt_cap_get(cap));
-}
-
-static struct attribute_group pt_cap_group = {
-	.name	= "caps",
-};
-
-PMU_FORMAT_ATTR(cyc,		"config:1"	);
-PMU_FORMAT_ATTR(mtc,		"config:9"	);
-PMU_FORMAT_ATTR(tsc,		"config:10"	);
-PMU_FORMAT_ATTR(noretcomp,	"config:11"	);
-PMU_FORMAT_ATTR(mtc_period,	"config:14-17"	);
-PMU_FORMAT_ATTR(cyc_thresh,	"config:19-22"	);
-PMU_FORMAT_ATTR(psb_period,	"config:24-27"	);
-
-static struct attribute *pt_formats_attr[] = {
-	&format_attr_cyc.attr,
-	&format_attr_mtc.attr,
-	&format_attr_tsc.attr,
-	&format_attr_noretcomp.attr,
-	&format_attr_mtc_period.attr,
-	&format_attr_cyc_thresh.attr,
-	&format_attr_psb_period.attr,
-	NULL,
-};
-
-static struct attribute_group pt_format_group = {
-	.name	= "format",
-	.attrs	= pt_formats_attr,
-};
-
-static const struct attribute_group *pt_attr_groups[] = {
-	&pt_cap_group,
-	&pt_format_group,
-	NULL,
-};
-
-static int __init pt_pmu_hw_init(void)
-{
-	struct dev_ext_attribute *de_attrs;
-	struct attribute **attrs;
-	size_t size;
-	int ret;
-	long i;
-
-	attrs = NULL;
-
-	for (i = 0; i < PT_CPUID_LEAVES; i++) {
-		cpuid_count(20, i,
-			    &pt_pmu.caps[CR_EAX + i*PT_CPUID_REGS_NUM],
-			    &pt_pmu.caps[CR_EBX + i*PT_CPUID_REGS_NUM],
-			    &pt_pmu.caps[CR_ECX + i*PT_CPUID_REGS_NUM],
-			    &pt_pmu.caps[CR_EDX + i*PT_CPUID_REGS_NUM]);
-	}
-
-	ret = -ENOMEM;
-	size = sizeof(struct attribute *) * (ARRAY_SIZE(pt_caps)+1);
-	attrs = kzalloc(size, GFP_KERNEL);
-	if (!attrs)
-		goto fail;
-
-	size = sizeof(struct dev_ext_attribute) * (ARRAY_SIZE(pt_caps)+1);
-	de_attrs = kzalloc(size, GFP_KERNEL);
-	if (!de_attrs)
-		goto fail;
-
-	for (i = 0; i < ARRAY_SIZE(pt_caps); i++) {
-		struct dev_ext_attribute *de_attr = de_attrs + i;
-
-		de_attr->attr.attr.name = pt_caps[i].name;
-
-		sysfs_attr_init(&de_attr->attr.attr);
-
-		de_attr->attr.attr.mode		= S_IRUGO;
-		de_attr->attr.show		= pt_cap_show;
-		de_attr->var			= (void *)i;
-
-		attrs[i] = &de_attr->attr.attr;
-	}
-
-	pt_cap_group.attrs = attrs;
-
-	return 0;
-
-fail:
-	kfree(attrs);
-
-	return ret;
-}
-
-#define RTIT_CTL_CYC_PSB (RTIT_CTL_CYCLEACC	| \
-			  RTIT_CTL_CYC_THRESH	| \
-			  RTIT_CTL_PSB_FREQ)
-
-#define RTIT_CTL_MTC	(RTIT_CTL_MTC_EN	| \
-			 RTIT_CTL_MTC_RANGE)
-
-#define PT_CONFIG_MASK (RTIT_CTL_TSC_EN		| \
-			RTIT_CTL_DISRETC	| \
-			RTIT_CTL_CYC_PSB	| \
-			RTIT_CTL_MTC)
-
-static bool pt_event_valid(struct perf_event *event)
-{
-	u64 config = event->attr.config;
-	u64 allowed, requested;
-
-	if ((config & PT_CONFIG_MASK) != config)
-		return false;
-
-	if (config & RTIT_CTL_CYC_PSB) {
-		if (!pt_cap_get(PT_CAP_psb_cyc))
-			return false;
-
-		allowed = pt_cap_get(PT_CAP_psb_periods);
-		requested = (config & RTIT_CTL_PSB_FREQ) >>
-			RTIT_CTL_PSB_FREQ_OFFSET;
-		if (requested && (!(allowed & BIT(requested))))
-			return false;
-
-		allowed = pt_cap_get(PT_CAP_cycle_thresholds);
-		requested = (config & RTIT_CTL_CYC_THRESH) >>
-			RTIT_CTL_CYC_THRESH_OFFSET;
-		if (requested && (!(allowed & BIT(requested))))
-			return false;
-	}
-
-	if (config & RTIT_CTL_MTC) {
-		/*
-		 * In the unlikely case that CPUID lists valid mtc periods,
-		 * but not the mtc capability, drop out here.
-		 *
-		 * Spec says that setting mtc period bits while mtc bit in
-		 * CPUID is 0 will #GP, so better safe than sorry.
-		 */
-		if (!pt_cap_get(PT_CAP_mtc))
-			return false;
-
-		allowed = pt_cap_get(PT_CAP_mtc_periods);
-		if (!allowed)
-			return false;
-
-		requested = (config & RTIT_CTL_MTC_RANGE) >>
-			RTIT_CTL_MTC_RANGE_OFFSET;
-
-		if (!(allowed & BIT(requested)))
-			return false;
-	}
-
-	return true;
-}
-
-/*
- * PT configuration helpers
- * These all are cpu affine and operate on a local PT
- */
-
-static void pt_config(struct perf_event *event)
-{
-	u64 reg;
-
-	if (!event->hw.itrace_started) {
-		event->hw.itrace_started = 1;
-		wrmsrl(MSR_IA32_RTIT_STATUS, 0);
-	}
-
-	reg = RTIT_CTL_TOPA | RTIT_CTL_BRANCH_EN | RTIT_CTL_TRACEEN;
-
-	if (!event->attr.exclude_kernel)
-		reg |= RTIT_CTL_OS;
-	if (!event->attr.exclude_user)
-		reg |= RTIT_CTL_USR;
-
-	reg |= (event->attr.config & PT_CONFIG_MASK);
-
-	wrmsrl(MSR_IA32_RTIT_CTL, reg);
-}
-
-static void pt_config_start(bool start)
-{
-	u64 ctl;
-
-	rdmsrl(MSR_IA32_RTIT_CTL, ctl);
-	if (start)
-		ctl |= RTIT_CTL_TRACEEN;
-	else
-		ctl &= ~RTIT_CTL_TRACEEN;
-	wrmsrl(MSR_IA32_RTIT_CTL, ctl);
-
-	/*
-	 * A wrmsr that disables trace generation serializes other PT
-	 * registers and causes all data packets to be written to memory,
-	 * but a fence is required for the data to become globally visible.
-	 *
-	 * The below WMB, separating data store and aux_head store matches
-	 * the consumer's RMB that separates aux_head load and data load.
-	 */
-	if (!start)
-		wmb();
-}
-
-static void pt_config_buffer(void *buf, unsigned int topa_idx,
-			     unsigned int output_off)
-{
-	u64 reg;
-
-	wrmsrl(MSR_IA32_RTIT_OUTPUT_BASE, virt_to_phys(buf));
-
-	reg = 0x7f | ((u64)topa_idx << 7) | ((u64)output_off << 32);
-
-	wrmsrl(MSR_IA32_RTIT_OUTPUT_MASK, reg);
-}
-
-/*
- * Keep ToPA table-related metadata on the same page as the actual table,
- * taking up a few words from the top
- */
-
-#define TENTS_PER_PAGE (((PAGE_SIZE - 40) / sizeof(struct topa_entry)) - 1)
-
-/**
- * struct topa - page-sized ToPA table with metadata at the top
- * @table:	actual ToPA table entries, as understood by PT hardware
- * @list:	linkage to struct pt_buffer's list of tables
- * @phys:	physical address of this page
- * @offset:	offset of the first entry in this table in the buffer
- * @size:	total size of all entries in this table
- * @last:	index of the last initialized entry in this table
- */
-struct topa {
-	struct topa_entry	table[TENTS_PER_PAGE];
-	struct list_head	list;
-	u64			phys;
-	u64			offset;
-	size_t			size;
-	int			last;
-};
-
-/* make -1 stand for the last table entry */
-#define TOPA_ENTRY(t, i) ((i) == -1 ? &(t)->table[(t)->last] : &(t)->table[(i)])
-
-/**
- * topa_alloc() - allocate page-sized ToPA table
- * @cpu:	CPU on which to allocate.
- * @gfp:	Allocation flags.
- *
- * Return:	On success, return the pointer to ToPA table page.
- */
-static struct topa *topa_alloc(int cpu, gfp_t gfp)
-{
-	int node = cpu_to_node(cpu);
-	struct topa *topa;
-	struct page *p;
-
-	p = alloc_pages_node(node, gfp | __GFP_ZERO, 0);
-	if (!p)
-		return NULL;
-
-	topa = page_address(p);
-	topa->last = 0;
-	topa->phys = page_to_phys(p);
-
-	/*
-	 * In case of singe-entry ToPA, always put the self-referencing END
-	 * link as the 2nd entry in the table
-	 */
-	if (!pt_cap_get(PT_CAP_topa_multiple_entries)) {
-		TOPA_ENTRY(topa, 1)->base = topa->phys >> TOPA_SHIFT;
-		TOPA_ENTRY(topa, 1)->end = 1;
-	}
-
-	return topa;
-}
-
-/**
- * topa_free() - free a page-sized ToPA table
- * @topa:	Table to deallocate.
- */
-static void topa_free(struct topa *topa)
-{
-	free_page((unsigned long)topa);
-}
-
-/**
- * topa_insert_table() - insert a ToPA table into a buffer
- * @buf:	 PT buffer that's being extended.
- * @topa:	 New topa table to be inserted.
- *
- * If it's the first table in this buffer, set up buffer's pointers
- * accordingly; otherwise, add a END=1 link entry to @topa to the current
- * "last" table and adjust the last table pointer to @topa.
- */
-static void topa_insert_table(struct pt_buffer *buf, struct topa *topa)
-{
-	struct topa *last = buf->last;
-
-	list_add_tail(&topa->list, &buf->tables);
-
-	if (!buf->first) {
-		buf->first = buf->last = buf->cur = topa;
-		return;
-	}
-
-	topa->offset = last->offset + last->size;
-	buf->last = topa;
-
-	if (!pt_cap_get(PT_CAP_topa_multiple_entries))
-		return;
-
-	BUG_ON(last->last != TENTS_PER_PAGE - 1);
-
-	TOPA_ENTRY(last, -1)->base = topa->phys >> TOPA_SHIFT;
-	TOPA_ENTRY(last, -1)->end = 1;
-}
-
-/**
- * topa_table_full() - check if a ToPA table is filled up
- * @topa:	ToPA table.
- */
-static bool topa_table_full(struct topa *topa)
-{
-	/* single-entry ToPA is a special case */
-	if (!pt_cap_get(PT_CAP_topa_multiple_entries))
-		return !!topa->last;
-
-	return topa->last == TENTS_PER_PAGE - 1;
-}
-
-/**
- * topa_insert_pages() - create a list of ToPA tables
- * @buf:	PT buffer being initialized.
- * @gfp:	Allocation flags.
- *
- * This initializes a list of ToPA tables with entries from
- * the data_pages provided by rb_alloc_aux().
- *
- * Return:	0 on success or error code.
- */
-static int topa_insert_pages(struct pt_buffer *buf, gfp_t gfp)
-{
-	struct topa *topa = buf->last;
-	int order = 0;
-	struct page *p;
-
-	p = virt_to_page(buf->data_pages[buf->nr_pages]);
-	if (PagePrivate(p))
-		order = page_private(p);
-
-	if (topa_table_full(topa)) {
-		topa = topa_alloc(buf->cpu, gfp);
-		if (!topa)
-			return -ENOMEM;
-
-		topa_insert_table(buf, topa);
-	}
-
-	TOPA_ENTRY(topa, -1)->base = page_to_phys(p) >> TOPA_SHIFT;
-	TOPA_ENTRY(topa, -1)->size = order;
-	if (!buf->snapshot && !pt_cap_get(PT_CAP_topa_multiple_entries)) {
-		TOPA_ENTRY(topa, -1)->intr = 1;
-		TOPA_ENTRY(topa, -1)->stop = 1;
-	}
-
-	topa->last++;
-	topa->size += sizes(order);
-
-	buf->nr_pages += 1ul << order;
-
-	return 0;
-}
-
-/**
- * pt_topa_dump() - print ToPA tables and their entries
- * @buf:	PT buffer.
- */
-static void pt_topa_dump(struct pt_buffer *buf)
-{
-	struct topa *topa;
-
-	list_for_each_entry(topa, &buf->tables, list) {
-		int i;
-
-		pr_debug("# table @%p (%016Lx), off %llx size %zx\n", topa->table,
-			 topa->phys, topa->offset, topa->size);
-		for (i = 0; i < TENTS_PER_PAGE; i++) {
-			pr_debug("# entry @%p (%lx sz %u %c%c%c) raw=%16llx\n",
-				 &topa->table[i],
-				 (unsigned long)topa->table[i].base << TOPA_SHIFT,
-				 sizes(topa->table[i].size),
-				 topa->table[i].end ?  'E' : ' ',
-				 topa->table[i].intr ? 'I' : ' ',
-				 topa->table[i].stop ? 'S' : ' ',
-				 *(u64 *)&topa->table[i]);
-			if ((pt_cap_get(PT_CAP_topa_multiple_entries) &&
-			     topa->table[i].stop) ||
-			    topa->table[i].end)
-				break;
-		}
-	}
-}
-
-/**
- * pt_buffer_advance() - advance to the next output region
- * @buf:	PT buffer.
- *
- * Advance the current pointers in the buffer to the next ToPA entry.
- */
-static void pt_buffer_advance(struct pt_buffer *buf)
-{
-	buf->output_off = 0;
-	buf->cur_idx++;
-
-	if (buf->cur_idx == buf->cur->last) {
-		if (buf->cur == buf->last)
-			buf->cur = buf->first;
-		else
-			buf->cur = list_entry(buf->cur->list.next, struct topa,
-					      list);
-		buf->cur_idx = 0;
-	}
-}
-
-/**
- * pt_update_head() - calculate current offsets and sizes
- * @pt:		Per-cpu pt context.
- *
- * Update buffer's current write pointer position and data size.
- */
-static void pt_update_head(struct pt *pt)
-{
-	struct pt_buffer *buf = perf_get_aux(&pt->handle);
-	u64 topa_idx, base, old;
-
-	/* offset of the first region in this table from the beginning of buf */
-	base = buf->cur->offset + buf->output_off;
-
-	/* offset of the current output region within this table */
-	for (topa_idx = 0; topa_idx < buf->cur_idx; topa_idx++)
-		base += sizes(buf->cur->table[topa_idx].size);
-
-	if (buf->snapshot) {
-		local_set(&buf->data_size, base);
-	} else {
-		old = (local64_xchg(&buf->head, base) &
-		       ((buf->nr_pages << PAGE_SHIFT) - 1));
-		if (base < old)
-			base += buf->nr_pages << PAGE_SHIFT;
-
-		local_add(base - old, &buf->data_size);
-	}
-}
-
-/**
- * pt_buffer_region() - obtain current output region's address
- * @buf:	PT buffer.
- */
-static void *pt_buffer_region(struct pt_buffer *buf)
-{
-	return phys_to_virt(buf->cur->table[buf->cur_idx].base << TOPA_SHIFT);
-}
-
-/**
- * pt_buffer_region_size() - obtain current output region's size
- * @buf:	PT buffer.
- */
-static size_t pt_buffer_region_size(struct pt_buffer *buf)
-{
-	return sizes(buf->cur->table[buf->cur_idx].size);
-}
-
-/**
- * pt_handle_status() - take care of possible status conditions
- * @pt:		Per-cpu pt context.
- */
-static void pt_handle_status(struct pt *pt)
-{
-	struct pt_buffer *buf = perf_get_aux(&pt->handle);
-	int advance = 0;
-	u64 status;
-
-	rdmsrl(MSR_IA32_RTIT_STATUS, status);
-
-	if (status & RTIT_STATUS_ERROR) {
-		pr_err_ratelimited("ToPA ERROR encountered, trying to recover\n");
-		pt_topa_dump(buf);
-		status &= ~RTIT_STATUS_ERROR;
-	}
-
-	if (status & RTIT_STATUS_STOPPED) {
-		status &= ~RTIT_STATUS_STOPPED;
-
-		/*
-		 * On systems that only do single-entry ToPA, hitting STOP
-		 * means we are already losing data; need to let the decoder
-		 * know.
-		 */
-		if (!pt_cap_get(PT_CAP_topa_multiple_entries) ||
-		    buf->output_off == sizes(TOPA_ENTRY(buf->cur, buf->cur_idx)->size)) {
-			local_inc(&buf->lost);
-			advance++;
-		}
-	}
-
-	/*
-	 * Also on single-entry ToPA implementations, interrupt will come
-	 * before the output reaches its output region's boundary.
-	 */
-	if (!pt_cap_get(PT_CAP_topa_multiple_entries) && !buf->snapshot &&
-	    pt_buffer_region_size(buf) - buf->output_off <= TOPA_PMI_MARGIN) {
-		void *head = pt_buffer_region(buf);
-
-		/* everything within this margin needs to be zeroed out */
-		memset(head + buf->output_off, 0,
-		       pt_buffer_region_size(buf) -
-		       buf->output_off);
-		advance++;
-	}
-
-	if (advance)
-		pt_buffer_advance(buf);
-
-	wrmsrl(MSR_IA32_RTIT_STATUS, status);
-}
-
-/**
- * pt_read_offset() - translate registers into buffer pointers
- * @buf:	PT buffer.
- *
- * Set buffer's output pointers from MSR values.
- */
-static void pt_read_offset(struct pt_buffer *buf)
-{
-	u64 offset, base_topa;
-
-	rdmsrl(MSR_IA32_RTIT_OUTPUT_BASE, base_topa);
-	buf->cur = phys_to_virt(base_topa);
-
-	rdmsrl(MSR_IA32_RTIT_OUTPUT_MASK, offset);
-	/* offset within current output region */
-	buf->output_off = offset >> 32;
-	/* index of current output region within this table */
-	buf->cur_idx = (offset & 0xffffff80) >> 7;
-}
-
-/**
- * pt_topa_next_entry() - obtain index of the first page in the next ToPA entry
- * @buf:	PT buffer.
- * @pg:		Page offset in the buffer.
- *
- * When advancing to the next output region (ToPA entry), given a page offset
- * into the buffer, we need to find the offset of the first page in the next
- * region.
- */
-static unsigned int pt_topa_next_entry(struct pt_buffer *buf, unsigned int pg)
-{
-	struct topa_entry *te = buf->topa_index[pg];
-
-	/* one region */
-	if (buf->first == buf->last && buf->first->last == 1)
-		return pg;
-
-	do {
-		pg++;
-		pg &= buf->nr_pages - 1;
-	} while (buf->topa_index[pg] == te);
-
-	return pg;
-}
-
-/**
- * pt_buffer_reset_markers() - place interrupt and stop bits in the buffer
- * @buf:	PT buffer.
- * @handle:	Current output handle.
- *
- * Place INT and STOP marks to prevent overwriting old data that the consumer
- * hasn't yet collected and waking up the consumer after a certain fraction of
- * the buffer has filled up. Only needed and sensible for non-snapshot counters.
- *
- * This obviously relies on buf::head to figure out buffer markers, so it has
- * to be called after pt_buffer_reset_offsets() and before the hardware tracing
- * is enabled.
- */
-static int pt_buffer_reset_markers(struct pt_buffer *buf,
-				   struct perf_output_handle *handle)
-
-{
-	unsigned long head = local64_read(&buf->head);
-	unsigned long idx, npages, wakeup;
-
-	/* can't stop in the middle of an output region */
-	if (buf->output_off + handle->size + 1 <
-	    sizes(TOPA_ENTRY(buf->cur, buf->cur_idx)->size))
-		return -EINVAL;
-
-
-	/* single entry ToPA is handled by marking all regions STOP=1 INT=1 */
-	if (!pt_cap_get(PT_CAP_topa_multiple_entries))
-		return 0;
-
-	/* clear STOP and INT from current entry */
-	buf->topa_index[buf->stop_pos]->stop = 0;
-	buf->topa_index[buf->intr_pos]->intr = 0;
-
-	/* how many pages till the STOP marker */
-	npages = handle->size >> PAGE_SHIFT;
-
-	/* if it's on a page boundary, fill up one more page */
-	if (!offset_in_page(head + handle->size + 1))
-		npages++;
-
-	idx = (head >> PAGE_SHIFT) + npages;
-	idx &= buf->nr_pages - 1;
-	buf->stop_pos = idx;
-
-	wakeup = handle->wakeup >> PAGE_SHIFT;
-
-	/* in the worst case, wake up the consumer one page before hard stop */
-	idx = (head >> PAGE_SHIFT) + npages - 1;
-	if (idx > wakeup)
-		idx = wakeup;
-
-	idx &= buf->nr_pages - 1;
-	buf->intr_pos = idx;
-
-	buf->topa_index[buf->stop_pos]->stop = 1;
-	buf->topa_index[buf->intr_pos]->intr = 1;
-
-	return 0;
-}
-
-/**
- * pt_buffer_setup_topa_index() - build topa_index[] table of regions
- * @buf:	PT buffer.
- *
- * topa_index[] references output regions indexed by offset into the
- * buffer for purposes of quick reverse lookup.
- */
-static void pt_buffer_setup_topa_index(struct pt_buffer *buf)
-{
-	struct topa *cur = buf->first, *prev = buf->last;
-	struct topa_entry *te_cur = TOPA_ENTRY(cur, 0),
-		*te_prev = TOPA_ENTRY(prev, prev->last - 1);
-	int pg = 0, idx = 0;
-
-	while (pg < buf->nr_pages) {
-		int tidx;
-
-		/* pages within one topa entry */
-		for (tidx = 0; tidx < 1 << te_cur->size; tidx++, pg++)
-			buf->topa_index[pg] = te_prev;
-
-		te_prev = te_cur;
-
-		if (idx == cur->last - 1) {
-			/* advance to next topa table */
-			idx = 0;
-			cur = list_entry(cur->list.next, struct topa, list);
-		} else {
-			idx++;
-		}
-		te_cur = TOPA_ENTRY(cur, idx);
-	}
-
-}
-
-/**
- * pt_buffer_reset_offsets() - adjust buffer's write pointers from aux_head
- * @buf:	PT buffer.
- * @head:	Write pointer (aux_head) from AUX buffer.
- *
- * Find the ToPA table and entry corresponding to given @head and set buffer's
- * "current" pointers accordingly. This is done after we have obtained the
- * current aux_head position from a successful call to perf_aux_output_begin()
- * to make sure the hardware is writing to the right place.
- *
- * This function modifies buf::{cur,cur_idx,output_off} that will be programmed
- * into PT msrs when the tracing is enabled and buf::head and buf::data_size,
- * which are used to determine INT and STOP markers' locations by a subsequent
- * call to pt_buffer_reset_markers().
- */
-static void pt_buffer_reset_offsets(struct pt_buffer *buf, unsigned long head)
-{
-	int pg;
-
-	if (buf->snapshot)
-		head &= (buf->nr_pages << PAGE_SHIFT) - 1;
-
-	pg = (head >> PAGE_SHIFT) & (buf->nr_pages - 1);
-	pg = pt_topa_next_entry(buf, pg);
-
-	buf->cur = (struct topa *)((unsigned long)buf->topa_index[pg] & PAGE_MASK);
-	buf->cur_idx = ((unsigned long)buf->topa_index[pg] -
-			(unsigned long)buf->cur) / sizeof(struct topa_entry);
-	buf->output_off = head & (sizes(buf->cur->table[buf->cur_idx].size) - 1);
-
-	local64_set(&buf->head, head);
-	local_set(&buf->data_size, 0);
-}
-
-/**
- * pt_buffer_fini_topa() - deallocate ToPA structure of a buffer
- * @buf:	PT buffer.
- */
-static void pt_buffer_fini_topa(struct pt_buffer *buf)
-{
-	struct topa *topa, *iter;
-
-	list_for_each_entry_safe(topa, iter, &buf->tables, list) {
-		/*
-		 * right now, this is in free_aux() path only, so
-		 * no need to unlink this table from the list
-		 */
-		topa_free(topa);
-	}
-}
-
-/**
- * pt_buffer_init_topa() - initialize ToPA table for pt buffer
- * @buf:	PT buffer.
- * @size:	Total size of all regions within this ToPA.
- * @gfp:	Allocation flags.
- */
-static int pt_buffer_init_topa(struct pt_buffer *buf, unsigned long nr_pages,
-			       gfp_t gfp)
-{
-	struct topa *topa;
-	int err;
-
-	topa = topa_alloc(buf->cpu, gfp);
-	if (!topa)
-		return -ENOMEM;
-
-	topa_insert_table(buf, topa);
-
-	while (buf->nr_pages < nr_pages) {
-		err = topa_insert_pages(buf, gfp);
-		if (err) {
-			pt_buffer_fini_topa(buf);
-			return -ENOMEM;
-		}
-	}
-
-	pt_buffer_setup_topa_index(buf);
-
-	/* link last table to the first one, unless we're double buffering */
-	if (pt_cap_get(PT_CAP_topa_multiple_entries)) {
-		TOPA_ENTRY(buf->last, -1)->base = buf->first->phys >> TOPA_SHIFT;
-		TOPA_ENTRY(buf->last, -1)->end = 1;
-	}
-
-	pt_topa_dump(buf);
-	return 0;
-}
-
-/**
- * pt_buffer_setup_aux() - set up topa tables for a PT buffer
- * @cpu:	Cpu on which to allocate, -1 means current.
- * @pages:	Array of pointers to buffer pages passed from perf core.
- * @nr_pages:	Number of pages in the buffer.
- * @snapshot:	If this is a snapshot/overwrite counter.
- *
- * This is a pmu::setup_aux callback that sets up ToPA tables and all the
- * bookkeeping for an AUX buffer.
- *
- * Return:	Our private PT buffer structure.
- */
-static void *
-pt_buffer_setup_aux(int cpu, void **pages, int nr_pages, bool snapshot)
-{
-	struct pt_buffer *buf;
-	int node, ret;
-
-	if (!nr_pages)
-		return NULL;
-
-	if (cpu == -1)
-		cpu = raw_smp_processor_id();
-	node = cpu_to_node(cpu);
-
-	buf = kzalloc_node(offsetof(struct pt_buffer, topa_index[nr_pages]),
-			   GFP_KERNEL, node);
-	if (!buf)
-		return NULL;
-
-	buf->cpu = cpu;
-	buf->snapshot = snapshot;
-	buf->data_pages = pages;
-
-	INIT_LIST_HEAD(&buf->tables);
-
-	ret = pt_buffer_init_topa(buf, nr_pages, GFP_KERNEL);
-	if (ret) {
-		kfree(buf);
-		return NULL;
-	}
-
-	return buf;
-}
-
-/**
- * pt_buffer_free_aux() - perf AUX deallocation path callback
- * @data:	PT buffer.
- */
-static void pt_buffer_free_aux(void *data)
-{
-	struct pt_buffer *buf = data;
-
-	pt_buffer_fini_topa(buf);
-	kfree(buf);
-}
-
-/**
- * pt_buffer_is_full() - check if the buffer is full
- * @buf:	PT buffer.
- * @pt:		Per-cpu pt handle.
- *
- * If the user hasn't read data from the output region that aux_head
- * points to, the buffer is considered full: the user needs to read at
- * least this region and update aux_tail to point past it.
- */
-static bool pt_buffer_is_full(struct pt_buffer *buf, struct pt *pt)
-{
-	if (buf->snapshot)
-		return false;
-
-	if (local_read(&buf->data_size) >= pt->handle.size)
-		return true;
-
-	return false;
-}
-
-/**
- * intel_pt_interrupt() - PT PMI handler
- */
-void intel_pt_interrupt(void)
-{
-	struct pt *pt = this_cpu_ptr(&pt_ctx);
-	struct pt_buffer *buf;
-	struct perf_event *event = pt->handle.event;
-
-	/*
-	 * There may be a dangling PT bit in the interrupt status register
-	 * after PT has been disabled by pt_event_stop(). Make sure we don't
-	 * do anything (particularly, re-enable) for this event here.
-	 */
-	if (!ACCESS_ONCE(pt->handle_nmi))
-		return;
-
-	pt_config_start(false);
-
-	if (!event)
-		return;
-
-	buf = perf_get_aux(&pt->handle);
-	if (!buf)
-		return;
-
-	pt_read_offset(buf);
-
-	pt_handle_status(pt);
-
-	pt_update_head(pt);
-
-	perf_aux_output_end(&pt->handle, local_xchg(&buf->data_size, 0),
-			    local_xchg(&buf->lost, 0));
-
-	if (!event->hw.state) {
-		int ret;
-
-		buf = perf_aux_output_begin(&pt->handle, event);
-		if (!buf) {
-			event->hw.state = PERF_HES_STOPPED;
-			return;
-		}
-
-		pt_buffer_reset_offsets(buf, pt->handle.head);
-		/* snapshot counters don't use PMI, so it's safe */
-		ret = pt_buffer_reset_markers(buf, &pt->handle);
-		if (ret) {
-			perf_aux_output_end(&pt->handle, 0, true);
-			return;
-		}
-
-		pt_config_buffer(buf->cur->table, buf->cur_idx,
-				 buf->output_off);
-		pt_config(event);
-	}
-}
-
-/*
- * PMU callbacks
- */
-
-static void pt_event_start(struct perf_event *event, int mode)
-{
-	struct pt *pt = this_cpu_ptr(&pt_ctx);
-	struct pt_buffer *buf = perf_get_aux(&pt->handle);
-
-	if (!buf || pt_buffer_is_full(buf, pt)) {
-		event->hw.state = PERF_HES_STOPPED;
-		return;
-	}
-
-	ACCESS_ONCE(pt->handle_nmi) = 1;
-	event->hw.state = 0;
-
-	pt_config_buffer(buf->cur->table, buf->cur_idx,
-			 buf->output_off);
-	pt_config(event);
-}
-
-static void pt_event_stop(struct perf_event *event, int mode)
-{
-	struct pt *pt = this_cpu_ptr(&pt_ctx);
-
-	/*
-	 * Protect against the PMI racing with disabling wrmsr,
-	 * see comment in intel_pt_interrupt().
-	 */
-	ACCESS_ONCE(pt->handle_nmi) = 0;
-	pt_config_start(false);
-
-	if (event->hw.state == PERF_HES_STOPPED)
-		return;
-
-	event->hw.state = PERF_HES_STOPPED;
-
-	if (mode & PERF_EF_UPDATE) {
-		struct pt_buffer *buf = perf_get_aux(&pt->handle);
-
-		if (!buf)
-			return;
-
-		if (WARN_ON_ONCE(pt->handle.event != event))
-			return;
-
-		pt_read_offset(buf);
-
-		pt_handle_status(pt);
-
-		pt_update_head(pt);
-	}
-}
-
-static void pt_event_del(struct perf_event *event, int mode)
-{
-	struct pt *pt = this_cpu_ptr(&pt_ctx);
-	struct pt_buffer *buf;
-
-	pt_event_stop(event, PERF_EF_UPDATE);
-
-	buf = perf_get_aux(&pt->handle);
-
-	if (buf) {
-		if (buf->snapshot)
-			pt->handle.head =
-				local_xchg(&buf->data_size,
-					   buf->nr_pages << PAGE_SHIFT);
-		perf_aux_output_end(&pt->handle, local_xchg(&buf->data_size, 0),
-				    local_xchg(&buf->lost, 0));
-	}
-}
-
-static int pt_event_add(struct perf_event *event, int mode)
-{
-	struct pt_buffer *buf;
-	struct pt *pt = this_cpu_ptr(&pt_ctx);
-	struct hw_perf_event *hwc = &event->hw;
-	int ret = -EBUSY;
-
-	if (pt->handle.event)
-		goto fail;
-
-	buf = perf_aux_output_begin(&pt->handle, event);
-	ret = -EINVAL;
-	if (!buf)
-		goto fail_stop;
-
-	pt_buffer_reset_offsets(buf, pt->handle.head);
-	if (!buf->snapshot) {
-		ret = pt_buffer_reset_markers(buf, &pt->handle);
-		if (ret)
-			goto fail_end_stop;
-	}
-
-	if (mode & PERF_EF_START) {
-		pt_event_start(event, 0);
-		ret = -EBUSY;
-		if (hwc->state == PERF_HES_STOPPED)
-			goto fail_end_stop;
-	} else {
-		hwc->state = PERF_HES_STOPPED;
-	}
-
-	return 0;
-
-fail_end_stop:
-	perf_aux_output_end(&pt->handle, 0, true);
-fail_stop:
-	hwc->state = PERF_HES_STOPPED;
-fail:
-	return ret;
-}
-
-static void pt_event_read(struct perf_event *event)
-{
-}
-
-static void pt_event_destroy(struct perf_event *event)
-{
-	x86_del_exclusive(x86_lbr_exclusive_pt);
-}
-
-static int pt_event_init(struct perf_event *event)
-{
-	if (event->attr.type != pt_pmu.pmu.type)
-		return -ENOENT;
-
-	if (!pt_event_valid(event))
-		return -EINVAL;
-
-	if (x86_add_exclusive(x86_lbr_exclusive_pt))
-		return -EBUSY;
-
-	event->destroy = pt_event_destroy;
-
-	return 0;
-}
-
-void cpu_emergency_stop_pt(void)
-{
-	struct pt *pt = this_cpu_ptr(&pt_ctx);
-
-	if (pt->handle.event)
-		pt_event_stop(pt->handle.event, PERF_EF_UPDATE);
-}
-
-static __init int pt_init(void)
-{
-	int ret, cpu, prior_warn = 0;
-
-	BUILD_BUG_ON(sizeof(struct topa) > PAGE_SIZE);
-
-	if (!test_cpu_cap(&boot_cpu_data, X86_FEATURE_INTEL_PT))
-		return -ENODEV;
-
-	get_online_cpus();
-	for_each_online_cpu(cpu) {
-		u64 ctl;
-
-		ret = rdmsrl_safe_on_cpu(cpu, MSR_IA32_RTIT_CTL, &ctl);
-		if (!ret && (ctl & RTIT_CTL_TRACEEN))
-			prior_warn++;
-	}
-	put_online_cpus();
-
-	if (prior_warn) {
-		x86_add_exclusive(x86_lbr_exclusive_pt);
-		pr_warn("PT is enabled at boot time, doing nothing\n");
-
-		return -EBUSY;
-	}
-
-	ret = pt_pmu_hw_init();
-	if (ret)
-		return ret;
-
-	if (!pt_cap_get(PT_CAP_topa_output)) {
-		pr_warn("ToPA output is not supported on this CPU\n");
-		return -ENODEV;
-	}
-
-	if (!pt_cap_get(PT_CAP_topa_multiple_entries))
-		pt_pmu.pmu.capabilities =
-			PERF_PMU_CAP_AUX_NO_SG | PERF_PMU_CAP_AUX_SW_DOUBLEBUF;
-
-	pt_pmu.pmu.capabilities	|= PERF_PMU_CAP_EXCLUSIVE | PERF_PMU_CAP_ITRACE;
-	pt_pmu.pmu.attr_groups	= pt_attr_groups;
-	pt_pmu.pmu.task_ctx_nr	= perf_sw_context;
-	pt_pmu.pmu.event_init	= pt_event_init;
-	pt_pmu.pmu.add		= pt_event_add;
-	pt_pmu.pmu.del		= pt_event_del;
-	pt_pmu.pmu.start	= pt_event_start;
-	pt_pmu.pmu.stop		= pt_event_stop;
-	pt_pmu.pmu.read		= pt_event_read;
-	pt_pmu.pmu.setup_aux	= pt_buffer_setup_aux;
-	pt_pmu.pmu.free_aux	= pt_buffer_free_aux;
-	ret = perf_pmu_register(&pt_pmu.pmu, "intel_pt", -1);
-
-	return ret;
-}
-arch_initcall(pt_init);