3 files changed, 85 insertions, 43 deletions

diff --git a/drivers/net/wireless/intel/iwlwifi/fw/acpi.c b/drivers/net/wireless/intel/iwlwifi/fw/acpi.c
index 15248b064380..d8b7776a8dde 100644
--- a/drivers/net/wireless/intel/iwlwifi/fw/acpi.c
+++ b/drivers/net/wireless/intel/iwlwifi/fw/acpi.c
@@ -80,19 +80,45 @@ static void *iwl_acpi_get_dsm_object(struct device *dev, int rev, int func,
 }
 
 /*
- * Evaluate a DSM with no arguments and a single u8 return value (inside a
- * buffer object), verify and return that value.
+ * Generic function to evaluate a DSM with no arguments
+ * and an integer return value,
+ * (as an integer object or inside a buffer object),
+ * verify and assign the value in the "value" parameter.
+ * return 0 in success and the appropriate errno otherwise.
  */
-int iwl_acpi_get_dsm_u8(struct device *dev, int rev, int func)
+static int iwl_acpi_get_dsm_integer(struct device *dev, int rev, int func,
+				    u64 *value, size_t expected_size)
 {
 	union acpi_object *obj;
-	int ret;
+	int ret = 0;
 
 	obj = iwl_acpi_get_dsm_object(dev, rev, func, NULL);
-	if (IS_ERR(obj))
+	if (IS_ERR(obj)) {
+		IWL_DEBUG_DEV_RADIO(dev,
+				    "Failed to get  DSM object. func= %d\n",
+				    func);
 		return -ENOENT;
+	}
+
+	if (obj->type == ACPI_TYPE_INTEGER) {
+		*value = obj->integer.value;
+	} else if (obj->type == ACPI_TYPE_BUFFER) {
+		__le64 le_value = 0;
 
-	if (obj->type != ACPI_TYPE_BUFFER) {
+		if (WARN_ON_ONCE(expected_size > sizeof(le_value)))
+			return -EINVAL;
+
+		/* if the buffer size doesn't match the expected size */
+		if (obj->buffer.length != expected_size)
+			IWL_DEBUG_DEV_RADIO(dev,
+					    "ACPI: DSM invalid buffer size, padding or truncating (%d)\n",
+					    obj->buffer.length);
+
+		 /* assuming LE from Intel BIOS spec */
+		memcpy(&le_value, obj->buffer.pointer,
+		       min_t(size_t, expected_size, (size_t)obj->buffer.length));
+		*value = le64_to_cpu(le_value);
+	} else {
 		IWL_DEBUG_DEV_RADIO(dev,
 				    "ACPI: DSM method did not return a valid object, type=%d\n",
 				    obj->type);
@@ -100,15 +126,6 @@ int iwl_acpi_get_dsm_u8(struct device *dev, int rev, int func)
 		goto out;
 	}
 
-	if (obj->buffer.length != sizeof(u8)) {
-		IWL_DEBUG_DEV_RADIO(dev,
-				    "ACPI: DSM method returned invalid buffer, length=%d\n",
-				    obj->buffer.length);
-		ret = -EINVAL;
-		goto out;
-	}
-
-	ret = obj->buffer.pointer[0];
 	IWL_DEBUG_DEV_RADIO(dev,
 			    "ACPI: DSM method evaluated: func=%d, ret=%d\n",
 			    func, ret);
@@ -116,6 +133,24 @@ out:
 	ACPI_FREE(obj);
 	return ret;
 }
+
+/*
+ * Evaluate a DSM with no arguments and a u8 return value,
+ */
+int iwl_acpi_get_dsm_u8(struct device *dev, int rev, int func, u8 *value)
+{
+	int ret;
+	u64 val;
+
+	ret = iwl_acpi_get_dsm_integer(dev, rev, func, &val, sizeof(u8));
+
+	if (ret < 0)
+		return ret;
+
+	/* cast val (u64) to be u8 */
+	*value = (u8)val;
+	return 0;
+}
 IWL_EXPORT_SYMBOL(iwl_acpi_get_dsm_u8);
 
 union acpi_object *iwl_acpi_get_wifi_pkg(struct device *dev,
diff --git a/drivers/net/wireless/intel/iwlwifi/fw/acpi.h b/drivers/net/wireless/intel/iwlwifi/fw/acpi.h
index 042dd247d387..1cce30d1ef55 100644
--- a/drivers/net/wireless/intel/iwlwifi/fw/acpi.h
+++ b/drivers/net/wireless/intel/iwlwifi/fw/acpi.h
@@ -1,7 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause */
 /*
  * Copyright (C) 2017 Intel Deutschland GmbH
- * Copyright (C) 2018-2020 Intel Corporation
+ * Copyright (C) 2018-2021 Intel Corporation
  */
 #ifndef __iwl_fw_acpi__
 #define __iwl_fw_acpi__
@@ -99,7 +99,7 @@ struct iwl_fw_runtime;
 
 void *iwl_acpi_get_object(struct device *dev, acpi_string method);
 
-int iwl_acpi_get_dsm_u8(struct device *dev, int rev, int func);
+int iwl_acpi_get_dsm_u8(struct device *dev, int rev, int func, u8 *value);
 
 union acpi_object *iwl_acpi_get_wifi_pkg(struct device *dev,
 					 union acpi_object *data,
@@ -159,7 +159,8 @@ static inline void *iwl_acpi_get_dsm_object(struct device *dev, int rev,
 	return ERR_PTR(-ENOENT);
 }
 
-static inline int iwl_acpi_get_dsm_u8(struct device *dev, int rev, int func)
+static inline
+int iwl_acpi_get_dsm_u8(struct device *dev, int rev, int func, u8 *value)
 {
 	return -ENOENT;
 }
diff --git a/drivers/net/wireless/intel/iwlwifi/fw/pnvm.c b/drivers/net/wireless/intel/iwlwifi/fw/pnvm.c
index 6d8f7bff1243..895a907acdf0 100644
--- a/drivers/net/wireless/intel/iwlwifi/fw/pnvm.c
+++ b/drivers/net/wireless/intel/iwlwifi/fw/pnvm.c
@@ -224,40 +224,46 @@ static int iwl_pnvm_parse(struct iwl_trans *trans, const u8 *data,
 int iwl_pnvm_load(struct iwl_trans *trans,
 		  struct iwl_notif_wait_data *notif_wait)
 {
-	const struct firmware *pnvm;
 	struct iwl_notification_wait pnvm_wait;
 	static const u16 ntf_cmds[] = { WIDE_ID(REGULATORY_AND_NVM_GROUP,
 						PNVM_INIT_COMPLETE_NTFY) };
-	char pnvm_name[64];
-	int ret;
 
 	/* if the SKU_ID is empty, there's nothing to do */
 	if (!trans->sku_id[0] && !trans->sku_id[1] && !trans->sku_id[2])
 		return 0;
 
-	/* if we already have it, nothing to do either */
-	if (trans->pnvm_loaded)
-		return 0;
+	/* load from disk only if we haven't done it (or tried) before */
+	if (!trans->pnvm_loaded) {
+		const struct firmware *pnvm;
+		char pnvm_name[64];
+		int ret;
+
+		/*
+		 * The prefix unfortunately includes a hyphen at the end, so
+		 * don't add the dot here...
+		 */
+		snprintf(pnvm_name, sizeof(pnvm_name), "%spnvm",
+			 trans->cfg->fw_name_pre);
+
+		/* ...but replace the hyphen with the dot here. */
+		if (strlen(trans->cfg->fw_name_pre) < sizeof(pnvm_name))
+			pnvm_name[strlen(trans->cfg->fw_name_pre) - 1] = '.';
+
+		ret = firmware_request_nowarn(&pnvm, pnvm_name, trans->dev);
+		if (ret) {
+			IWL_DEBUG_FW(trans, "PNVM file %s not found %d\n",
+				     pnvm_name, ret);
+			/*
+			 * Pretend we've loaded it - at least we've tried and
+			 * couldn't load it at all, so there's no point in
+			 * trying again over and over.
+			 */
+			trans->pnvm_loaded = true;
+		} else {
+			iwl_pnvm_parse(trans, pnvm->data, pnvm->size);
 
-	/*
-	 * The prefix unfortunately includes a hyphen at the end, so
-	 * don't add the dot here...
-	 */
-	snprintf(pnvm_name, sizeof(pnvm_name), "%spnvm",
-		 trans->cfg->fw_name_pre);
-
-	/* ...but replace the hyphen with the dot here. */
-	if (strlen(trans->cfg->fw_name_pre) < sizeof(pnvm_name))
-		pnvm_name[strlen(trans->cfg->fw_name_pre) - 1] = '.';
-
-	ret = firmware_request_nowarn(&pnvm, pnvm_name, trans->dev);
-	if (ret) {
-		IWL_DEBUG_FW(trans, "PNVM file %s not found %d\n",
-			     pnvm_name, ret);
-	} else {
-		iwl_pnvm_parse(trans, pnvm->data, pnvm->size);
-
-		release_firmware(pnvm);
+			release_firmware(pnvm);
+		}
 	}
 
 	iwl_init_notification_wait(notif_wait, &pnvm_wait,