Merge tag 'scmi-fixes-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux into soc/fixes

Arm SCMI fixes for v6.3

Few fixes addressing issues around validation of device tree SCMI node,
allowing raw SCMI access even on systems which fail to probe the normal
driver stack, duplicate header inclusion, clean up return statement using
literal values instead of variable to simplify and use of devm_bitmap_zalloc
instead of devm_kcalloc to improve semantic.

* tag 'scmi-fixes-6.3' of git://git.kernel.org/pub/scm/linux/kernel/git/sudeep.holla/linux:
firmware: arm_scmi: Use the bitmap API to allocate bitmaps
firmware: arm_scmi: Fix device node validation for mailbox transport
firmware: arm_scmi: Fix raw coexistence mode behaviour on failure path
firmware: arm_scmi: Remove duplicate include header inclusion
firmware: arm_scmi: Return a literal instead of a variable
firmware: arm_scmi: Clean up a return statement in scmi_probe

Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Arnd Bergmann <[e-mail]>

drivers/firmware/arm_scmi/bus.c

···
 #include <linux/kernel.h>
 #include <linux/slab.h>
 #include <linux/device.h>
-#include <linux/of.h>
 
 #include "common.h"
 
···
 	/* Nothing to do. */
 	if (!phead) {
 		mutex_unlock(&scmi_requested_devices_mtx);
-		return scmi_dev;
+		return NULL;
 	}
 
 	/* Walk the list of requested devices for protocol and create them */

drivers/firmware/arm_scmi/driver.c

···
 	hash_init(info->pending_xfers);
 
 	/* Allocate a bitmask sized to hold MSG_TOKEN_MAX tokens */
-	info->xfer_alloc_table = devm_kcalloc(dev, BITS_TO_LONGS(MSG_TOKEN_MAX),
-					      sizeof(long), GFP_KERNEL);
+	info->xfer_alloc_table = devm_bitmap_zalloc(dev, MSG_TOKEN_MAX,
+						    GFP_KERNEL);
 	if (!info->xfer_alloc_table)
 		return -ENOMEM;
 
···
 	struct scmi_handle *handle;
 	const struct scmi_desc *desc;
 	struct scmi_info *info;
+	bool coex = IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT_COEX);
 	struct device *dev = &pdev->dev;
 	struct device_node *child, *np = dev->of_node;
 
···
 			dev_warn(dev, "Failed to setup SCMI debugfs.\n");
 
 		if (IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT)) {
-			bool coex =
-			      IS_ENABLED(CONFIG_ARM_SCMI_RAW_MODE_SUPPORT_COEX);
-
 			ret = scmi_debugfs_raw_mode_setup(info);
 			if (!coex) {
 				if (ret)
 					goto clear_dev_req_notifier;
 
-				/* Bail out anyway when coex enabled */
-				return ret;
+				/* Bail out anyway when coex disabled. */
+				return 0;
 			}
 
 			/* Coex enabled, carry on in any case. */
···
 	ret = scmi_protocol_acquire(handle, SCMI_PROTOCOL_BASE);
 	if (ret) {
 		dev_err(dev, "unable to communicate with SCMI\n");
+		if (coex)
+			return 0;
 		goto notification_exit;
 	}
 

drivers/firmware/arm_scmi/mailbox.c

···
 					   "#mbox-cells", idx, NULL);
 }
 
+static int mailbox_chan_validate(struct device *cdev)
+{
+	int num_mb, num_sh, ret = 0;
+	struct device_node *np = cdev->of_node;
+
+	num_mb = of_count_phandle_with_args(np, "mboxes", "#mbox-cells");
+	num_sh = of_count_phandle_with_args(np, "shmem", NULL);
+	/* Bail out if mboxes and shmem descriptors are inconsistent */
+	if (num_mb <= 0 || num_sh > 2 || num_mb != num_sh) {
+		dev_warn(cdev, "Invalid channel descriptor for '%s'\n",
+			 of_node_full_name(np));
+		return -EINVAL;
+	}
+
+	if (num_sh > 1) {
+		struct device_node *np_tx, *np_rx;
+
+		np_tx = of_parse_phandle(np, "shmem", 0);
+		np_rx = of_parse_phandle(np, "shmem", 1);
+		/* SCMI Tx and Rx shared mem areas have to be distinct */
+		if (!np_tx || !np_rx || np_tx == np_rx) {
+			dev_warn(cdev, "Invalid shmem descriptor for '%s'\n",
+				 of_node_full_name(np));
+			ret = -EINVAL;
+		}
+
+		of_node_put(np_tx);
+		of_node_put(np_rx);
+	}
+
+	return ret;
+}
+
 static int mailbox_chan_setup(struct scmi_chan_info *cinfo, struct device *dev,
 			      bool tx)
 {
···
 	struct mbox_client *cl;
 	resource_size_t size;
 	struct resource res;
+
+	ret = mailbox_chan_validate(cdev);
+	if (ret)
+		return ret;
 
 	smbox = devm_kzalloc(dev, sizeof(*smbox), GFP_KERNEL);
 	if (!smbox)