Commit 880a66e0 authored by Suman Anna's avatar Suman Anna Committed by Bjorn Andersson
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remoteproc: pru: Fix and cleanup firmware interrupt mapping logic 



The PRU firmware interrupt mappings are configured and unconfigured in
.start() and .stop() callbacks respectively using the variables 'evt_count'
and a 'mapped_irq' pointer. These variables are modified only during these
callbacks but are not re-initialized/reset properly during unwind or
failure paths. These stale values caused a kernel crash while stopping a
PRU remoteproc running a different firmware with no events on a subsequent
run after a previous run that was running a firmware with events.

Fix this crash by ensuring that the evt_count is 0 and the mapped_irq
pointer is set to NULL in pru_dispose_irq_mapping(). Also, reset these
variables properly during any failures in the .start() callback. While
at this, the pru_dispose_irq_mapping() callsites are all made to look
the same, moving any conditional logic to inside the function.

Reviewed-by: default avatarMathieu Poirier <mathieu.poirier@linaro.org>
Fixes: c75c9fda ("remoteproc: pru: Add support for PRU specific interrupt configuration")
Reported-by: default avatarVignesh Raghavendra <vigneshr@ti.com>
Signed-off-by: default avatarSuman Anna <s-anna@ti.com>
Link: https://lore.kernel.org/r/20210407155641.5501-4-s-anna@ti.com


Signed-off-by: default avatarBjorn Andersson <bjorn.andersson@linaro.org>
parent 1fe72bcf

drivers/remoteproc/pru_rproc.c

+17 −5
Original line number Diff line number Diff line
@@ -266,12 +266,17 @@ static void pru_rproc_create_debug_entries(struct rproc *rproc) 


static void pru_dispose_irq_mapping(struct pru_rproc *pru)

{

	while (pru->evt_count--) {

	if (!pru->mapped_irq)

		return;



	while (pru->evt_count) {

		pru->evt_count--;

		if (pru->mapped_irq[pru->evt_count] > 0)

			irq_dispose_mapping(pru->mapped_irq[pru->evt_count]);

	}



	kfree(pru->mapped_irq);

	pru->mapped_irq = NULL;

}



/*
@@ -307,8 +312,10 @@ static int pru_handle_intrmap(struct rproc *rproc) 
	pru->evt_count = rsc->num_evts;

	pru->mapped_irq = kcalloc(pru->evt_count, sizeof(unsigned int),

				  GFP_KERNEL);

	if (!pru->mapped_irq)

	if (!pru->mapped_irq) {

		pru->evt_count = 0;

		return -ENOMEM;

	}



	/*

	 * parse and fill in system event to interrupt channel and
@@ -317,13 +324,19 @@ static int pru_handle_intrmap(struct rproc *rproc) 
	 * corresponding sibling PRUSS INTC node.

	 */

	parent = of_get_parent(dev_of_node(pru->dev));

	if (!parent)

	if (!parent) {

		kfree(pru->mapped_irq);

		pru->mapped_irq = NULL;

		pru->evt_count = 0;

		return -ENODEV;

	}



	irq_parent = of_get_child_by_name(parent, "interrupt-controller");

	of_node_put(parent);

	if (!irq_parent) {

		kfree(pru->mapped_irq);

		pru->mapped_irq = NULL;

		pru->evt_count = 0;

		return -ENODEV;

	}
@@ -398,7 +411,6 @@ static int pru_rproc_stop(struct rproc *rproc) 
	pru_control_write_reg(pru, PRU_CTRL_CTRL, val);



	/* dispose irq mapping - new firmware can provide new mapping */

	if (pru->mapped_irq)

	pru_dispose_irq_mapping(pru);



	return 0;