[PATCH 3/3] mailbox: zynqmp-ipi: Fix SGI cleanup on unbind

[Harini T <harini.t@amd.com>]

The driver incorrectly determines SGI vs SPI interrupts by checking IRQ
number < 16, which fails with dynamic IRQ allocation. During unbind,
this causes improper SGI cleanup leading to kernel crash.

Add explicit irq_type field to pdata for reliable identification of SGI
interrupts (type-2) and only clean up SGI resources when appropriate.

Signed-off-by: Harini T <harini.t@amd.com>
---
 drivers/mailbox/zynqmp-ipi-mailbox.c | 15 ++++++++++-----
 1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/mailbox/zynqmp-ipi-mailbox.c b/drivers/mailbox/zynqmp-ipi-mailbox.c
index 3b806d1f89bb..1af758a406e2 100644
--- a/drivers/mailbox/zynqmp-ipi-mailbox.c
+++ b/drivers/mailbox/zynqmp-ipi-mailbox.c
@@ -62,7 +62,8 @@
 #define DST_BIT_POS	9U
 #define SRC_BITMASK	GENMASK(11, 8)
 
-#define MAX_SGI 16
+/* Macro to represent SGI type for IPI IRQs */
+#define IPI_IRQ_TYPE_SGI	2
 
 /*
  * Module parameters
@@ -121,6 +122,7 @@ struct zynqmp_ipi_mbox {
  * @dev:                  device pointer corresponding to the Xilinx ZynqMP
  *                        IPI agent
  * @irq:                  IPI agent interrupt ID
+ * @irq_type:             IPI SGI or SPI IRQ type
  * @method:               IPI SMC or HVC is going to be used
  * @local_id:             local IPI agent ID
  * @virq_sgi:             IRQ number mapped to SGI
@@ -130,6 +132,7 @@ struct zynqmp_ipi_mbox {
 struct zynqmp_ipi_pdata {
 	struct device *dev;
 	int irq;
+	unsigned int irq_type;
 	unsigned int method;
 	u32 local_id;
 	int virq_sgi;
@@ -887,7 +890,7 @@ static void zynqmp_ipi_free_mboxes(struct zynqmp_ipi_pdata *pdata)
 	struct zynqmp_ipi_mbox *ipi_mbox;
 	int i;
 
-	if (pdata->irq < MAX_SGI)
+	if (pdata->irq_type == IPI_IRQ_TYPE_SGI)
 		xlnx_mbox_cleanup_sgi(pdata);
 
 	i = pdata->num_mboxes;
@@ -956,14 +959,16 @@ static int zynqmp_ipi_probe(struct platform_device *pdev)
 		dev_err(dev, "failed to parse interrupts\n");
 		goto free_mbox_dev;
 	}
-	ret = out_irq.args[1];
+
+	/* Use interrupt type to distinguish SGI and SPI interrupts */
+	pdata->irq_type = out_irq.args[0];
 
 	/*
 	 * If Interrupt number is in SGI range, then request SGI else request
 	 * IPI system IRQ.
 	 */
-	if (ret < MAX_SGI) {
-		pdata->irq = ret;
+	if (pdata->irq_type == IPI_IRQ_TYPE_SGI) {
+		pdata->irq = out_irq.args[1];
 		ret = xlnx_mbox_init_sgi(pdev, pdata->irq, pdata);
 		if (ret)
 			goto free_mbox_dev;
-- 
2.43.0