static void bts_event_stop(struct perf_event *event, int flags)
{
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
struct bts_ctx *bts = this_cpu_ptr(&bts_ctx);
struct bts_buffer *buf = NULL;
int state = READ_ONCE(bts->state);
if (state == BTS_STATE_ACTIVE)
__bts_event_stop(event, BTS_STATE_STOPPED);
if (state != BTS_STATE_STOPPED)
buf = perf_get_aux(&bts->handle);
event->hw.state |= PERF_HES_STOPPED;
if (flags & PERF_EF_UPDATE) {
bts_update(bts);
if (buf) {
if (buf->snapshot)
bts->handle.head =
local_xchg(&buf->data_size,
buf->nr_pages << PAGE_SHIFT);
perf_aux_output_end(&bts->handle, local_xchg(&buf->data_size, 0),
!!local_xchg(&buf->lost, 0));
}
cpuc->ds->bts_index = bts->ds_back.bts_buffer_base;
cpuc->ds->bts_buffer_base = bts->ds_back.bts_buffer_base;
cpuc->ds->bts_absolute_maximum = bts->ds_back.bts_absolute_maximum;
cpuc->ds->bts_interrupt_threshold = bts->ds_back.bts_interrupt_threshold;
}
}
static unsigned long etb_reset_buffer(struct coresight_device *csdev,
struct perf_output_handle *handle,
void *sink_config)
{
unsigned long size = 0;
struct cs_buffers *buf = sink_config;
if (buf) {
/*
* In snapshot mode ->data_size holds the new address of the
* ring buffer's head. The size itself is the whole address
* range since we want the latest information.
*/
if (buf->snapshot)
handle->head = local_xchg(&buf->data_size,
buf->nr_pages << PAGE_SHIFT);
/*
* Tell the tracer PMU how much we got in this run and if
* something went wrong along the way. Nobody else can use
* this cs_buffers instance until we are done. As such
* resetting parameters here and squaring off with the ring
* buffer API in the tracer PMU is fine.
*/
size = local_xchg(&buf->data_size, 0);
}
return size;
}
static void bts_update(struct bts_ctx *bts)
{
int cpu = raw_smp_processor_id();
struct debug_store *ds = per_cpu(cpu_hw_events, cpu).ds;
struct bts_buffer *buf = perf_get_aux(&bts->handle);
unsigned long index = ds->bts_index - ds->bts_buffer_base, old, head;
if (!buf)
return;
head = index + bts_buffer_offset(buf, buf->cur_buf);
old = local_xchg(&buf->head, head);
if (!buf->snapshot) {
if (old == head)
return;
if (ds->bts_index >= ds->bts_absolute_maximum)
local_inc(&buf->lost);
/*
* old and head are always in the same physical buffer, so we
* can subtract them to get the data size.
*/
local_add(head - old, &buf->data_size);
} else {
local_set(&buf->data_size, head);
}
}
static int tmc_enable_etf_sink_perf(struct coresight_device *csdev, u32 mode)
{
int ret = 0;
long val;
unsigned long flags;
struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
/* This shouldn't be happening */
if (WARN_ON(mode != CS_MODE_PERF))
return -EINVAL;
spin_lock_irqsave(&drvdata->spinlock, flags);
if (drvdata->reading) {
ret = -EINVAL;
goto out;
}
val = local_xchg(&drvdata->mode, mode);
/*
* In Perf mode there can be only one writer per sink. There
* is also no need to continue if the ETB/ETR is already operated
* from sysFS.
*/
if (val != CS_MODE_DISABLED) {
ret = -EINVAL;
goto out;
}
tmc_etb_enable_hw(drvdata);
out:
spin_unlock_irqrestore(&drvdata->spinlock, flags);
return ret;
}
int intel_bts_interrupt(void)
{
struct bts_ctx *bts = this_cpu_ptr(&bts_ctx);
struct perf_event *event = bts->handle.event;
struct bts_buffer *buf;
s64 old_head;
int err;
if (!event || !bts->started)
return 0;
buf = perf_get_aux(&bts->handle);
/*
* Skip snapshot counters: they don't use the interrupt, but
* there's no other way of telling, because the pointer will
* keep moving
*/
if (!buf || buf->snapshot)
return 0;
old_head = local_read(&buf->head);
bts_update(bts);
/* no new data */
if (old_head == local_read(&buf->head))
return 0;
perf_aux_output_end(&bts->handle, local_xchg(&buf->data_size, 0),
!!local_xchg(&buf->lost, 0));
buf = perf_aux_output_begin(&bts->handle, event);
if (!buf)
return 1;
err = bts_buffer_reset(buf, &bts->handle);
if (err)
perf_aux_output_end(&bts->handle, 0, false);
return 1;
}
static void bts_event_del(struct perf_event *event, int mode)
{
struct cpu_hw_events *cpuc = this_cpu_ptr(&cpu_hw_events);
struct bts_ctx *bts = this_cpu_ptr(&bts_ctx);
struct bts_buffer *buf = perf_get_aux(&bts->handle);
bts_event_stop(event, PERF_EF_UPDATE);
if (buf) {
if (buf->snapshot)
bts->handle.head =
local_xchg(&buf->data_size,
buf->nr_pages << PAGE_SHIFT);
perf_aux_output_end(&bts->handle, local_xchg(&buf->data_size, 0),
!!local_xchg(&buf->lost, 0));
}
cpuc->ds->bts_index = bts->ds_back.bts_buffer_base;
cpuc->ds->bts_buffer_base = bts->ds_back.bts_buffer_base;
cpuc->ds->bts_absolute_maximum = bts->ds_back.bts_absolute_maximum;
cpuc->ds->bts_interrupt_threshold = bts->ds_back.bts_interrupt_threshold;
}
static void tmc_disable_etf_sink(struct coresight_device *csdev)
{
long val;
unsigned long flags;
struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
spin_lock_irqsave(&drvdata->spinlock, flags);
if (drvdata->reading) {
spin_unlock_irqrestore(&drvdata->spinlock, flags);
return;
}
val = local_xchg(&drvdata->mode, CS_MODE_DISABLED);
/* Disable the TMC only if it needs to */
if (val != CS_MODE_DISABLED)
tmc_etb_disable_hw(drvdata);
spin_unlock_irqrestore(&drvdata->spinlock, flags);
dev_info(drvdata->dev, "TMC-ETB/ETF disabled\n");
}
int perf_output_begin(struct perf_output_handle *handle,
struct perf_event *event, unsigned int size)
{
struct ring_buffer *rb;
unsigned long tail, offset, head;
int have_lost;
struct perf_sample_data sample_data;
struct {
struct perf_event_header header;
u64 id;
u64 lost;
} lost_event;
rcu_read_lock();
/*
* For inherited events we send all the output towards the parent.
*/
if (event->parent)
event = event->parent;
rb = rcu_dereference(event->rb);
if (!rb)
goto out;
handle->rb = rb;
handle->event = event;
if (!rb->nr_pages)
goto out;
have_lost = local_read(&rb->lost);
if (have_lost) {
lost_event.header.size = sizeof(lost_event);
perf_event_header__init_id(&lost_event.header, &sample_data,
event);
size += lost_event.header.size;
}
perf_output_get_handle(handle);
do {
/*
* Userspace could choose to issue a mb() before updating the
* tail pointer. So that all reads will be completed before the
* write is issued.
*/
tail = ACCESS_ONCE(rb->user_page->data_tail);
smp_rmb();
offset = head = local_read(&rb->head);
head += size;
if (unlikely(!perf_output_space(rb, tail, offset, head)))
goto fail;
} while (local_cmpxchg(&rb->head, offset, head) != offset);
if (head - local_read(&rb->wakeup) > rb->watermark)
local_add(rb->watermark, &rb->wakeup);
handle->page = offset >> (PAGE_SHIFT + page_order(rb));
handle->page &= rb->nr_pages - 1;
handle->size = offset & ((PAGE_SIZE << page_order(rb)) - 1);
handle->addr = rb->data_pages[handle->page];
handle->addr += handle->size;
handle->size = (PAGE_SIZE << page_order(rb)) - handle->size;
if (have_lost) {
lost_event.header.type = PERF_RECORD_LOST;
lost_event.header.misc = 0;
lost_event.id = event->id;
lost_event.lost = local_xchg(&rb->lost, 0);
perf_output_put(handle, lost_event);
perf_event__output_id_sample(event, handle, &sample_data);
}
return 0;
fail:
local_inc(&rb->lost);
perf_output_put_handle(handle);
out:
rcu_read_unlock();
return -ENOSPC;
}
static int tmc_enable_etf_sink_sysfs(struct coresight_device *csdev, u32 mode)
{
int ret = 0;
bool used = false;
char *buf = NULL;
long val;
unsigned long flags;
struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
/* This shouldn't be happening */
if (WARN_ON(mode != CS_MODE_SYSFS))
return -EINVAL;
/*
* If we don't have a buffer release the lock and allocate memory.
* Otherwise keep the lock and move along.
*/
spin_lock_irqsave(&drvdata->spinlock, flags);
if (!drvdata->buf) {
spin_unlock_irqrestore(&drvdata->spinlock, flags);
/* Allocating the memory here while outside of the spinlock */
buf = kzalloc(drvdata->size, GFP_KERNEL);
if (!buf)
return -ENOMEM;
/* Let's try again */
spin_lock_irqsave(&drvdata->spinlock, flags);
}
if (drvdata->reading) {
ret = -EBUSY;
goto out;
}
val = local_xchg(&drvdata->mode, mode);
/*
* In sysFS mode we can have multiple writers per sink. Since this
* sink is already enabled no memory is needed and the HW need not be
* touched.
*/
if (val == CS_MODE_SYSFS)
goto out;
/*
* If drvdata::buf isn't NULL, memory was allocated for a previous
* trace run but wasn't read. If so simply zero-out the memory.
* Otherwise use the memory allocated above.
*
* The memory is freed when users read the buffer using the
* /dev/xyz.{etf|etb} interface. See tmc_read_unprepare_etf() for
* details.
*/
if (drvdata->buf) {
memset(drvdata->buf, 0, drvdata->size);
} else {
used = true;
drvdata->buf = buf;
}
tmc_etb_enable_hw(drvdata);
out:
spin_unlock_irqrestore(&drvdata->spinlock, flags);
/* Free memory outside the spinlock if need be */
if (!used && buf)
kfree(buf);
if (!ret)
dev_info(drvdata->dev, "TMC-ETB/ETF enabled\n");
return ret;
}
static int tmc_enable_etr_sink_sysfs(struct coresight_device *csdev, u32 mode)
{
int ret = 0;
bool used = false;
long val;
unsigned long flags;
void __iomem *vaddr = NULL;
dma_addr_t paddr;
struct tmc_drvdata *drvdata = dev_get_drvdata(csdev->dev.parent);
/* This shouldn't be happening */
if (WARN_ON(mode != CS_MODE_SYSFS))
return -EINVAL;
/*
* If we don't have a buffer release the lock and allocate memory.
* Otherwise keep the lock and move along.
*/
spin_lock_irqsave(&drvdata->spinlock, flags);
if (!drvdata->vaddr) {
spin_unlock_irqrestore(&drvdata->spinlock, flags);
/*
* Contiguous memory can't be allocated while a spinlock is
* held. As such allocate memory here and free it if a buffer
* has already been allocated (from a previous session).
*/
vaddr = dma_alloc_coherent(drvdata->dev, drvdata->size,
&paddr, GFP_KERNEL);
if (!vaddr)
return -ENOMEM;
/* Let's try again */
spin_lock_irqsave(&drvdata->spinlock, flags);
}
if (drvdata->reading) {
ret = -EBUSY;
goto out;
}
val = local_xchg(&drvdata->mode, mode);
/*
* In sysFS mode we can have multiple writers per sink. Since this
* sink is already enabled no memory is needed and the HW need not be
* touched.
*/
if (val == CS_MODE_SYSFS)
goto out;
/*
* If drvdata::buf == NULL, use the memory allocated above.
* Otherwise a buffer still exists from a previous session, so
* simply use that.
*/
if (drvdata->buf == NULL) {
used = true;
drvdata->vaddr = vaddr;
drvdata->paddr = paddr;
drvdata->buf = drvdata->vaddr;
}
memset(drvdata->vaddr, 0, drvdata->size);
tmc_etr_enable_hw(drvdata);
out:
spin_unlock_irqrestore(&drvdata->spinlock, flags);
/* Free memory outside the spinlock if need be */
if (!used && vaddr)
dma_free_coherent(drvdata->dev, drvdata->size, vaddr, paddr);
if (!ret)
dev_info(drvdata->dev, "TMC-ETR enabled\n");
return ret;
}
int intel_bts_interrupt(void)
{
struct debug_store *ds = this_cpu_ptr(&cpu_hw_events)->ds;
struct bts_ctx *bts = this_cpu_ptr(&bts_ctx);
struct perf_event *event = bts->handle.event;
struct bts_buffer *buf;
s64 old_head;
int err = -ENOSPC, handled = 0;
/*
* The only surefire way of knowing if this NMI is ours is by checking
* the write ptr against the PMI threshold.
*/
if (ds->bts_index >= ds->bts_interrupt_threshold)
handled = 1;
/*
* this is wrapped in intel_bts_enable_local/intel_bts_disable_local,
* so we can only be INACTIVE or STOPPED
*/
if (READ_ONCE(bts->state) == BTS_STATE_STOPPED)
return handled;
buf = perf_get_aux(&bts->handle);
if (!buf)
return handled;
/*
* Skip snapshot counters: they don't use the interrupt, but
* there's no other way of telling, because the pointer will
* keep moving
*/
if (buf->snapshot)
return 0;
old_head = local_read(&buf->head);
bts_update(bts);
/* no new data */
if (old_head == local_read(&buf->head))
return handled;
perf_aux_output_end(&bts->handle, local_xchg(&buf->data_size, 0),
!!local_xchg(&buf->lost, 0));
buf = perf_aux_output_begin(&bts->handle, event);
if (buf)
err = bts_buffer_reset(buf, &bts->handle);
if (err) {
WRITE_ONCE(bts->state, BTS_STATE_STOPPED);
if (buf) {
/*
* BTS_STATE_STOPPED should be visible before
* cleared handle::event
*/
barrier();
perf_aux_output_end(&bts->handle, 0, false);
}
}
return 1;
}