[PATCH 4.16 178/279] spi: bcm2835aux: ensure interrupts are enabled for shared handler

[PATCH 4.16 178/279] spi: bcm2835aux: ensure interrupts are enabled for shared handler

[Greg Kroah-Hartman]

4.16-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Rob Herring <robh@kernel.org>

[ Upstream commit bc519d9574618e47a0c788000fb78da95e18d953 ]

The BCM2835 AUX SPI has a shared interrupt line (with AUX UART).
Downstream fixes this with an AUX irqchip to demux the IRQ sources and a
DT change which breaks compatibility with older kernels. The AUX irqchip
was already rejected for upstream[1] and the DT change would break
working systems if the DTB is updated to a newer one. The latter issue
was brought to my attention by Alex Graf.

The root cause however is a bug in the shared handler. Shared handlers
must check that interrupts are actually enabled before servicing the
interrupt. Add a check that the TXEMPTY or IDLE interrupts are enabled.

[1] https://patchwork.kernel.org/patch/9781221/

Cc: Alexander Graf <agraf@suse.de>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Eric Anholt <eric@anholt.net>
Cc: Stefan Wahren <stefan.wahren@i2se.com>
Cc: Florian Fainelli <f.fainelli@gmail.com>
Cc: Ray Jui <rjui@broadcom.com>
Cc: Scott Branden <sbranden@broadcom.com>
Cc: bcm-kernel-feedback-list at broadcom.com
Cc: linux-spi at vger.kernel.org
Cc: linux-rpi-kernel at lists.infradead.org
Cc: linux-arm-kernel at lists.infradead.org
Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Eric Anholt <eric@anholt.net>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/spi/spi-bcm2835aux.c |    5 +++++
 1 file changed, 5 insertions(+)

--- a/drivers/spi/spi-bcm2835aux.c
+++ b/drivers/spi/spi-bcm2835aux.c
@@ -184,6 +184,11 @@ static irqreturn_t bcm2835aux_spi_interr
 	struct bcm2835aux_spi *bs = spi_master_get_devdata(master);
 	irqreturn_t ret = IRQ_NONE;
 
+	/* IRQ may be shared, so return if our interrupts are disabled */
+	if (!(bcm2835aux_rd(bs, BCM2835_AUX_SPI_CNTL1) &
+	      (BCM2835_AUX_SPI_CNTL1_TXEMPTY | BCM2835_AUX_SPI_CNTL1_IDLE)))
+		return ret;
+
 	/* check if we have data to read */
 	while (bs->rx_len &&
 	       (!(bcm2835aux_rd(bs, BCM2835_AUX_SPI_STAT) &

[PATCH 4.16 222/279] perf cs-etm: Support unknown_thread in cs_etm_auxtrace

[Greg Kroah-Hartman]

4.16-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Leo Yan <leo.yan@linaro.org>

[ Upstream commit 46d53620044f7b574c0f3216f8b4f2ce3559ce31 ]

CoreSight doesn't allocate thread structure for unknown_thread in ETM
auxtrace, so unknown_thread is NULL pointer.  If the perf data doesn't
contain valid tid and then cs_etm__mem_access() uses unknown_thread
instead as thread handler, this results in a segmentation fault when
thread__find_addr_map() accesses the thread handler.

This commit creates a new thread data which is used by unknown_thread, so
CoreSight tracing can roll back to use unknown_thread if perf data
doesn't include valid thread info.  This commit also releases thread
data for initialization failure case and for normal auxtrace free flow.

Signed-off-by: Leo Yan <leo.yan@linaro.org>
Acked-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-arm-kernel at lists.infradead.org
Link: http://lkml.kernel.org/r/1525924920-4381-1-git-send-email-leo.yan at linaro.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 tools/perf/util/cs-etm.c |   24 ++++++++++++++++++++++--
 1 file changed, 22 insertions(+), 2 deletions(-)

--- a/tools/perf/util/cs-etm.c
+++ b/tools/perf/util/cs-etm.c
@@ -212,6 +212,7 @@ static void cs_etm__free(struct perf_ses
 	for (i = 0; i < aux->num_cpu; i++)
 		zfree(&aux->metadata[i]);
 
+	thread__zput(aux->unknown_thread);
 	zfree(&aux->metadata);
 	zfree(&aux);
 }
@@ -980,6 +981,23 @@ int cs_etm__process_auxtrace_info(union
 	etm->auxtrace.free = cs_etm__free;
 	session->auxtrace = &etm->auxtrace;
 
+	etm->unknown_thread = thread__new(999999999, 999999999);
+	if (!etm->unknown_thread)
+		goto err_free_queues;
+
+	/*
+	 * Initialize list node so that at thread__zput() we can avoid
+	 * segmentation fault at list_del_init().
+	 */
+	INIT_LIST_HEAD(&etm->unknown_thread->node);
+
+	err = thread__set_comm(etm->unknown_thread, "unknown", 0);
+	if (err)
+		goto err_delete_thread;
+
+	if (thread__init_map_groups(etm->unknown_thread, etm->machine))
+		goto err_delete_thread;
+
 	if (dump_trace) {
 		cs_etm__print_auxtrace_info(auxtrace_info->priv, num_cpu);
 		return 0;
@@ -994,16 +1012,18 @@ int cs_etm__process_auxtrace_info(union
 
 	err = cs_etm__synth_events(etm, session);
 	if (err)
-		goto err_free_queues;
+		goto err_delete_thread;
 
 	err = auxtrace_queues__process_index(&etm->queues, session);
 	if (err)
-		goto err_free_queues;
+		goto err_delete_thread;
 
 	etm->data_queued = etm->queues.populated;
 
 	return 0;
 
+err_delete_thread:
+	thread__zput(etm->unknown_thread);
 err_free_queues:
 	auxtrace_queues__free(&etm->queues);
 	session->auxtrace = NULL;