} 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 * 4 + cd->reg];
+ u32 c = pt_pmu.caps[cd->leaf * PT_CPUID_REGS_NUM + cd->reg];
unsigned int shift = __ffs(cd->mask);
return (c & cd->mask) >> shift;
.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,
};
long i;
attrs = NULL;
- ret = -ENODEV;
- if (!test_cpu_cap(&boot_cpu_data, X86_FEATURE_INTEL_PT))
- goto fail;
for (i = 0; i < PT_CPUID_LEAVES; i++) {
cpuid_count(20, i,
- &pt_pmu.caps[CR_EAX + i*4],
- &pt_pmu.caps[CR_EBX + i*4],
- &pt_pmu.caps[CR_ECX + i*4],
- &pt_pmu.caps[CR_EDX + i*4]);
+ &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;
return ret;
}
-#define PT_CONFIG_MASK (RTIT_CTL_TSC_EN | RTIT_CTL_DISRETC)
+#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;
}
* These all are cpu affine and operate on a local PT
*/
-static bool pt_is_running(void)
-{
- u64 ctl;
-
- rdmsrl(MSR_IA32_RTIT_CTL, ctl);
-
- return !!(ctl & RTIT_CTL_TRACEEN);
-}
-
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)
* @handle: Current output handle.
*
* Place INT and STOP marks to prevent overwriting old data that the consumer
- * hasn't yet collected.
+ * 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;
- if (buf->snapshot)
- return 0;
-
/* 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))
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, ntopa = 0;
+ int pg = 0, idx = 0;
while (pg < buf->nr_pages) {
int tidx;
/* advance to next topa table */
idx = 0;
cur = list_entry(cur->list.next, struct topa, list);
- ntopa++;
- } else
+ } else {
idx++;
+ }
te_cur = TOPA_ENTRY(cur, idx);
}
* @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.
+ * "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)
{
}
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);
pt_config_buffer(buf->cur->table, buf->cur_idx,
buf->output_off);
- wrmsrl(MSR_IA32_RTIT_STATUS, 0);
pt_config(event);
}
}
struct pt *pt = this_cpu_ptr(&pt_ctx);
struct pt_buffer *buf = perf_get_aux(&pt->handle);
- if (pt_is_running() || !buf || pt_buffer_is_full(buf, pt)) {
+ if (!buf || pt_buffer_is_full(buf, pt)) {
event->hw.state = PERF_HES_STOPPED;
return;
}
pt_config_buffer(buf->cur->table, buf->cur_idx,
buf->output_off);
- wrmsrl(MSR_IA32_RTIT_STATUS, 0);
pt_config(event);
}
event->hw.state = PERF_HES_STOPPED;
if (mode & PERF_EF_UPDATE) {
- struct pt *pt = this_cpu_ptr(&pt_ctx);
struct pt_buffer *buf = perf_get_aux(&pt->handle);
if (!buf)
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;
return ret;
}
-
-module_init(pt_init);
+arch_initcall(pt_init);
Code Review / kvmfornfv.git / blobdiff