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-rw-r--r--arch/x86/events/intel/pt.c118
-rw-r--r--arch/x86/events/intel/pt.h2
2 files changed, 92 insertions, 28 deletions
diff --git a/arch/x86/events/intel/pt.c b/arch/x86/events/intel/pt.c
index 2f20d5a333c1..c87d163c2917 100644
--- a/arch/x86/events/intel/pt.c
+++ b/arch/x86/events/intel/pt.c
@@ -482,6 +482,8 @@ static u64 pt_config_filters(struct perf_event *event)
static void pt_config(struct perf_event *event)
{
+ struct pt *pt = this_cpu_ptr(&pt_ctx);
+ struct pt_buffer *buf = perf_get_aux(&pt->handle);
u64 reg;
/* First round: clear STATUS, in particular the PSB byte counter. */
@@ -491,7 +493,9 @@ static void pt_config(struct perf_event *event)
}
reg = pt_config_filters(event);
- reg |= RTIT_CTL_TOPA | RTIT_CTL_TRACEEN;
+ reg |= RTIT_CTL_TRACEEN;
+ if (!buf->single)
+ reg |= RTIT_CTL_TOPA;
/*
* Previously, we had BRANCH_EN on by default, but now that PT has
@@ -543,18 +547,6 @@ static void pt_config_stop(struct perf_event *event)
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);
-}
-
/**
* struct topa - ToPA metadata
* @list: linkage to struct pt_buffer's list of tables
@@ -612,6 +604,26 @@ static inline phys_addr_t topa_pfn(struct topa *topa)
#define TOPA_ENTRY_SIZE(t, i) (sizes(TOPA_ENTRY((t), (i))->size))
#define TOPA_ENTRY_PAGES(t, i) (1 << TOPA_ENTRY((t), (i))->size)
+static void pt_config_buffer(struct pt_buffer *buf)
+{
+ u64 reg, mask;
+ void *base;
+
+ if (buf->single) {
+ base = buf->data_pages[0];
+ mask = (buf->nr_pages * PAGE_SIZE - 1) >> 7;
+ } else {
+ base = topa_to_page(buf->cur)->table;
+ mask = (u64)buf->cur_idx;
+ }
+
+ wrmsrl(MSR_IA32_RTIT_OUTPUT_BASE, virt_to_phys(base));
+
+ reg = 0x7f | (mask << 7) | ((u64)buf->output_off << 32);
+
+ wrmsrl(MSR_IA32_RTIT_OUTPUT_MASK, reg);
+}
+
/**
* topa_alloc() - allocate page-sized ToPA table
* @cpu: CPU on which to allocate.
@@ -812,6 +824,11 @@ static void pt_update_head(struct pt *pt)
struct pt_buffer *buf = perf_get_aux(&pt->handle);
u64 topa_idx, base, old;
+ if (buf->single) {
+ local_set(&buf->data_size, buf->output_off);
+ return;
+ }
+
/* offset of the first region in this table from the beginning of buf */
base = buf->cur->offset + buf->output_off;
@@ -913,18 +930,21 @@ static void pt_handle_status(struct pt *pt)
*/
static void pt_read_offset(struct pt_buffer *buf)
{
- u64 offset, base_topa;
+ u64 offset, base;
struct topa_page *tp;
- rdmsrl(MSR_IA32_RTIT_OUTPUT_BASE, base_topa);
- tp = phys_to_virt(base_topa);
- buf->cur = &tp->topa;
+ if (!buf->single) {
+ rdmsrl(MSR_IA32_RTIT_OUTPUT_BASE, base);
+ tp = phys_to_virt(base);
+ buf->cur = &tp->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;
+ if (!buf->single)
+ buf->cur_idx = (offset & 0xffffff80) >> 7;
}
static struct topa_entry *
@@ -1040,6 +1060,9 @@ static int pt_buffer_reset_markers(struct pt_buffer *buf,
unsigned long head = local64_read(&buf->head);
unsigned long idx, npages, wakeup;
+ if (buf->single)
+ return 0;
+
/* can't stop in the middle of an output region */
if (buf->output_off + handle->size + 1 < pt_buffer_region_size(buf)) {
perf_aux_output_flag(handle, PERF_AUX_FLAG_TRUNCATED);
@@ -1121,13 +1144,17 @@ static void pt_buffer_reset_offsets(struct pt_buffer *buf, unsigned long head)
if (buf->snapshot)
head &= (buf->nr_pages << PAGE_SHIFT) - 1;
- pg = (head >> PAGE_SHIFT) & (buf->nr_pages - 1);
- te = pt_topa_entry_for_page(buf, pg);
+ if (!buf->single) {
+ pg = (head >> PAGE_SHIFT) & (buf->nr_pages - 1);
+ te = pt_topa_entry_for_page(buf, pg);
- cur_tp = topa_entry_to_page(te);
- buf->cur = &cur_tp->topa;
- buf->cur_idx = te - TOPA_ENTRY(buf->cur, 0);
- buf->output_off = head & (pt_buffer_region_size(buf) - 1);
+ cur_tp = topa_entry_to_page(te);
+ buf->cur = &cur_tp->topa;
+ buf->cur_idx = te - TOPA_ENTRY(buf->cur, 0);
+ buf->output_off = head & (pt_buffer_region_size(buf) - 1);
+ } else {
+ buf->output_off = head;
+ }
local64_set(&buf->head, head);
local_set(&buf->data_size, 0);
@@ -1141,6 +1168,9 @@ static void pt_buffer_fini_topa(struct pt_buffer *buf)
{
struct topa *topa, *iter;
+ if (buf->single)
+ return;
+
list_for_each_entry_safe(topa, iter, &buf->tables, list) {
/*
* right now, this is in free_aux() path only, so
@@ -1186,6 +1216,36 @@ static int pt_buffer_init_topa(struct pt_buffer *buf, int cpu,
return 0;
}
+static int pt_buffer_try_single(struct pt_buffer *buf, int nr_pages)
+{
+ struct page *p = virt_to_page(buf->data_pages[0]);
+ int ret = -ENOTSUPP, order = 0;
+
+ /*
+ * We can use single range output mode
+ * + in snapshot mode, where we don't need interrupts;
+ * + if the hardware supports it;
+ * + if the entire buffer is one contiguous allocation.
+ */
+ if (!buf->snapshot)
+ goto out;
+
+ if (!intel_pt_validate_hw_cap(PT_CAP_single_range_output))
+ goto out;
+
+ if (PagePrivate(p))
+ order = page_private(p);
+
+ if (1 << order != nr_pages)
+ goto out;
+
+ buf->single = true;
+ buf->nr_pages = nr_pages;
+ ret = 0;
+out:
+ return ret;
+}
+
/**
* pt_buffer_setup_aux() - set up topa tables for a PT buffer
* @cpu: Cpu on which to allocate, -1 means current.
@@ -1230,6 +1290,10 @@ pt_buffer_setup_aux(struct perf_event *event, void **pages,
INIT_LIST_HEAD(&buf->tables);
+ ret = pt_buffer_try_single(buf, nr_pages);
+ if (!ret)
+ return buf;
+
ret = pt_buffer_init_topa(buf, cpu, nr_pages, GFP_KERNEL);
if (ret) {
kfree(buf);
@@ -1396,8 +1460,7 @@ void intel_pt_interrupt(void)
return;
}
- pt_config_buffer(topa_to_page(buf->cur)->table, buf->cur_idx,
- buf->output_off);
+ pt_config_buffer(buf);
pt_config_start(event);
}
}
@@ -1461,8 +1524,7 @@ static void pt_event_start(struct perf_event *event, int mode)
WRITE_ONCE(pt->handle_nmi, 1);
hwc->state = 0;
- pt_config_buffer(topa_to_page(buf->cur)->table, buf->cur_idx,
- buf->output_off);
+ pt_config_buffer(buf);
pt_config(event);
return;
diff --git a/arch/x86/events/intel/pt.h b/arch/x86/events/intel/pt.h
index 1d2bb7572374..3f7818221b95 100644
--- a/arch/x86/events/intel/pt.h
+++ b/arch/x86/events/intel/pt.h
@@ -64,6 +64,7 @@ struct pt_pmu {
* @lost: if data was lost/truncated
* @head: logical write offset inside the buffer
* @snapshot: if this is for a snapshot/overwrite counter
+ * @single: use Single Range Output instead of ToPA
* @stop_pos: STOP topa entry index
* @intr_pos: INT topa entry index
* @stop_te: STOP topa entry pointer
@@ -80,6 +81,7 @@ struct pt_buffer {
local_t data_size;
local64_t head;
bool snapshot;
+ bool single;
long stop_pos, intr_pos;
struct topa_entry *stop_te, *intr_te;
void **data_pages;