Merge tag 'scmi-smccc-fixes-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux into arm/fixes

Arm SCMI and SMCCC fixes for v6.5

Set of fixes addressing issues:
1. Possible use of uninitialised results structure in the SMCCC SOC_ID
   driver if the driver fails to complete the initialisation
2. Missed signed error return value handling from simple_write_to_buffer()
   used in scmi_dbg_raw_mode_common_write()
3. The OF node reference obtained is not dropped if node is incompatible
   with "arm,scmi-shmem" in the mailbox as well as SMC transport channel
   setup
4. The possibility of a late response to an in-flight pending transaction
   that could end up triggering the interrupt handler after the SCMI core
   has cleaned up the transport channel as part of core driver remove

* tag 'scmi-smccc-fixes-6.5' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux:
  firmware: arm_scmi: Fix chan_free cleanup on SMC
  firmware: arm_scmi: Drop OF node reference in the transport channel setup
  firmware: arm_scmi: Fix signed error return values handling
  firmware: smccc: Fix use of uninitialised results structure

Link: https://lore.kernel.org/r/20230721114052.3371923-1-sudeep.holla@arm.com
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

drivers/firmware/arm_scmi/mailbox.c

@@ -166,8 +166,10 @@ static int mailbox_chan_setup(struct scmi_chan_info *cinfo, struct device *dev,
 		return -ENOMEM;
 
 	shmem = of_parse_phandle(cdev->of_node, "shmem", idx);
-	if (!of_device_is_compatible(shmem, "arm,scmi-shmem"))
+	if (!of_device_is_compatible(shmem, "arm,scmi-shmem")) {
+		of_node_put(shmem);
 		return -ENXIO;
+	}
 
 	ret = of_address_to_resource(shmem, 0, &res);
 	of_node_put(shmem);

drivers/firmware/arm_scmi/raw_mode.c

@@ -818,10 +818,13 @@ static ssize_t scmi_dbg_raw_mode_common_write(struct file *filp,
 	 * before sending it with a single RAW xfer.
 	 */
 	if (rd->tx_size < rd->tx_req_size) {
-		size_t cnt;
+		ssize_t cnt;
 
 		cnt = simple_write_to_buffer(rd->tx.buf, rd->tx.len, ppos,
 					     buf, count);
+		if (cnt < 0)
+			return cnt;
+
 		rd->tx_size += cnt;
 		if (cnt < count)
 			return cnt;

drivers/firmware/arm_scmi/smc.c

@@ -40,6 +40,7 @@
 /**
  * struct scmi_smc - Structure representing a SCMI smc transport
  *
+ * @irq: An optional IRQ for completion
  * @cinfo: SCMI channel info
  * @shmem: Transmit/Receive shared memory area
  * @shmem_lock: Lock to protect access to Tx/Rx shared memory area.
@@ -52,6 +53,7 @@
  */
 
 struct scmi_smc {
+	int irq;
 	struct scmi_chan_info *cinfo;
 	struct scmi_shared_mem __iomem *shmem;
 	/* Protect access to shmem area */
@@ -127,7 +129,7 @@ static int smc_chan_setup(struct scmi_chan_info *cinfo, struct device *dev,
 	struct resource res;
 	struct device_node *np;
 	u32 func_id;
-	int ret, irq;
+	int ret;
 
 	if (!tx)
 		return -ENODEV;
@@ -137,8 +139,10 @@ static int smc_chan_setup(struct scmi_chan_info *cinfo, struct device *dev,
 		return -ENOMEM;
 
 	np = of_parse_phandle(cdev->of_node, "shmem", 0);
-	if (!of_device_is_compatible(np, "arm,scmi-shmem"))
+	if (!of_device_is_compatible(np, "arm,scmi-shmem")) {
+		of_node_put(np);
 		return -ENXIO;
+	}
 
 	ret = of_address_to_resource(np, 0, &res);
 	of_node_put(np);
@@ -167,11 +171,10 @@ static int smc_chan_setup(struct scmi_chan_info *cinfo, struct device *dev,
 	 * completion of a message is signaled by an interrupt rather than by
 	 * the return of the SMC call.
 	 */
-	irq = of_irq_get_byname(cdev->of_node, "a2p");
-	if (irq > 0) {
-		ret = devm_request_irq(dev, irq, smc_msg_done_isr,
-				       IRQF_NO_SUSPEND,
-				       dev_name(dev), scmi_info);
+	scmi_info->irq = of_irq_get_byname(cdev->of_node, "a2p");
+	if (scmi_info->irq > 0) {
+		ret = request_irq(scmi_info->irq, smc_msg_done_isr,
+				  IRQF_NO_SUSPEND, dev_name(dev), scmi_info);
 		if (ret) {
 			dev_err(dev, "failed to setup SCMI smc irq\n");
 			return ret;
@@ -193,6 +196,10 @@ static int smc_chan_free(int id, void *p, void *data)
 	struct scmi_chan_info *cinfo = p;
 	struct scmi_smc *scmi_info = cinfo->transport_info;
 
+	/* Ignore any possible further reception on the IRQ path */
+	if (scmi_info->irq > 0)
+		free_irq(scmi_info->irq, scmi_info);
+
 	cinfo->transport_info = NULL;
 	scmi_info->cinfo = NULL;
 

drivers/firmware/smccc/soc_id.c

@@ -34,7 +34,6 @@ static struct soc_device_attribute *soc_dev_attr;
 
 static int __init smccc_soc_init(void)
 {
-	struct arm_smccc_res res;
 	int soc_id_rev, soc_id_version;
 	static char soc_id_str[20], soc_id_rev_str[12];
 	static char soc_id_jep106_id_str[12];
@@ -49,13 +48,13 @@ static int __init smccc_soc_init(void)
 	}
 
 	if (soc_id_version < 0) {
-		pr_err("ARCH_SOC_ID(0) returned error: %lx\n", res.a0);
+		pr_err("Invalid SoC Version: %x\n", soc_id_version);
 		return -EINVAL;
 	}
 
 	soc_id_rev = arm_smccc_get_soc_id_revision();
 	if (soc_id_rev < 0) {
-		pr_err("ARCH_SOC_ID(1) returned error: %lx\n", res.a0);
+		pr_err("Invalid SoC Revision: %x\n", soc_id_rev);
 		return -EINVAL;
 	}