wifi: iwlwifi: simplify getting DSM from ACPI

As DSMs are going to be read from UEFI too, we need a unified API
to get DSMs for both ACPI and UEFI.

The difference in getting DSM in each one of these methods (ACPI, UEFI)
is in the GUID, revision (0 for ACPI, 4 for UEFI), and size of the DSM
values (8 or 32 for ACPI, 32 for UEFI).

Therefore, change the iwl_acpi_get_dsm_x() to iwl_acpi_get_dsm() which
determines the GUID, revision (these two are the same for all WiFi DSMs),
and size (based on a func-to-size mapping) internally.

While at it, fix DSM_FUNC_RFI_CONFIG to expect a 32-bit value
(as defined in Intel BIOS spec) and not a 8-bit one.
Signed-off-by: Miri Korenblit <miriam.rachel.korenblit@intel.com>
Reviewed-by: Gregory Greenman <gregory.greenman@intel.com>
Link: https://msgid.link/20240201155157.1bcd7072a7a5.I344ee0a11abbc27da0c693187d1b8bee653aaeef@changeidSigned-off-by: Johannes Berg <johannes.berg@intel.com>

drivers/net/wireless/intel/iwlwifi/fw/acpi.c

@@ -12,7 +12,22 @@
 const guid_t iwl_guid = GUID_INIT(0xF21202BF, 0x8F78, 0x4DC6,
 				  0xA5, 0xB3, 0x1F, 0x73,
 				  0x8E, 0x28, 0x5A, 0xDE);
-IWL_EXPORT_SYMBOL(iwl_guid);
+
+static const size_t acpi_dsm_size[DSM_FUNC_NUM_FUNCS] = {
+	[DSM_FUNC_QUERY] =			sizeof(u32),
+	[DSM_FUNC_DISABLE_SRD] =		sizeof(u8),
+	[DSM_FUNC_ENABLE_INDONESIA_5G2] =	sizeof(u8),
+	[DSM_FUNC_ENABLE_6E] =			sizeof(u32),
+	[DSM_FUNC_REGULATORY_CONFIG] =		sizeof(u32),
+	/* Not supported in driver */
+	[5] =					(size_t)0,
+	[DSM_FUNC_11AX_ENABLEMENT] =		sizeof(u32),
+	[DSM_FUNC_ENABLE_UNII4_CHAN] =		sizeof(u32),
+	[DSM_FUNC_ACTIVATE_CHANNEL] =		sizeof(u32),
+	[DSM_FUNC_FORCE_DISABLE_CHANNELS] =	sizeof(u32),
+	[DSM_FUNC_ENERGY_DETECTION_THRESHOLD] =	sizeof(u32),
+	[DSM_FUNC_RFI_CONFIG] =			sizeof(u32),
+};
 
 static int iwl_acpi_get_handle(struct device *dev, acpi_string method,
 			       acpi_handle *ret_handle)
@@ -137,46 +152,42 @@ static int iwl_acpi_get_dsm_integer(struct device *dev, int rev, int func,
 }
 
 /*
- * Evaluate a DSM with no arguments and a u8 return value,
+ * This function receives a DSM function number, calculates its expected size
+ * according to Intel BIOS spec, and fills in the value in a 32-bit field.
+ * In case the expected size is smaller than 32-bit, padding will be added.
  */
-int iwl_acpi_get_dsm_u8(struct device *dev, int rev, int func,
-			const guid_t *guid, u8 *value)
+int iwl_acpi_get_dsm(struct iwl_fw_runtime *fwrt,
+		     enum iwl_dsm_funcs_rev_0 func, u32 *value)
 {
+	size_t expected_size;
+	u64 tmp;
 	int ret;
-	u64 val;
 
-	ret = iwl_acpi_get_dsm_integer(dev, rev, func,
-				       guid, &val, sizeof(u8));
+	BUILD_BUG_ON(ARRAY_SIZE(acpi_dsm_size) != DSM_FUNC_NUM_FUNCS);
 
-	if (ret < 0)
-		return ret;
+	if (WARN_ON(func >= ARRAY_SIZE(acpi_dsm_size)))
+		return -EINVAL;
 
-	/* cast val (u64) to be u8 */
-	*value = (u8)val;
-	return 0;
-}
-IWL_EXPORT_SYMBOL(iwl_acpi_get_dsm_u8);
+	expected_size = acpi_dsm_size[func];
 
-/*
- * Evaluate a DSM with no arguments and a u32 return value,
- */
-int iwl_acpi_get_dsm_u32(struct device *dev, int rev, int func,
-			 const guid_t *guid, u32 *value)
-{
-	int ret;
-	u64 val;
-
-	ret = iwl_acpi_get_dsm_integer(dev, rev, func,
-				       guid, &val, sizeof(u32));
+	/* Currently all ACPI DSMs are either 8-bit or 32-bit */
+	if (expected_size != sizeof(u8) && expected_size != sizeof(u32))
+		return -EOPNOTSUPP;
 
-	if (ret < 0)
+	ret = iwl_acpi_get_dsm_integer(fwrt->dev, ACPI_DSM_REV, func,
+				       &iwl_guid, &tmp, expected_size);
+	if (ret)
 		return ret;
 
-	/* cast val (u64) to be u32 */
-	*value = (u32)val;
+	if ((expected_size == sizeof(u8) && tmp != (u8)tmp) ||
+	    (expected_size == sizeof(u32) && tmp != (u32)tmp))
+		IWL_DEBUG_RADIO(fwrt,
+				"DSM value overflows the expected size, truncating\n");
+	*value = (u32)tmp;
+
 	return 0;
 }
-IWL_EXPORT_SYMBOL(iwl_acpi_get_dsm_u32);
+IWL_EXPORT_SYMBOL(iwl_acpi_get_dsm);
 
 static union acpi_object *
 iwl_acpi_get_wifi_pkg_range(struct device *dev,
@@ -800,7 +811,6 @@ int iwl_acpi_get_wgds_table(struct iwl_fw_runtime *fwrt)
 __le32 iwl_acpi_get_lari_config_bitmap(struct iwl_fw_runtime *fwrt)
 {
 	int ret;
-	u8 value;
 	u32 val;
 	__le32 config_bitmap = 0;
 
@@ -813,11 +823,10 @@ __le32 iwl_acpi_get_lari_config_bitmap(struct iwl_fw_runtime *fwrt)
 	case IWL_CFG_RF_TYPE_HR2:
 	case IWL_CFG_RF_TYPE_JF1:
 	case IWL_CFG_RF_TYPE_JF2:
-		ret = iwl_acpi_get_dsm_u8(fwrt->dev, 0,
-					  DSM_FUNC_ENABLE_INDONESIA_5G2,
-					  &iwl_guid, &value);
+		ret = iwl_acpi_get_dsm(fwrt, DSM_FUNC_ENABLE_INDONESIA_5G2,
+				       &val);
 
-		if (!ret && value == DSM_VALUE_INDONESIA_ENABLE)
+		if (!ret && val == DSM_VALUE_INDONESIA_ENABLE)
 			config_bitmap |=
 			    cpu_to_le32(LARI_CONFIG_ENABLE_5G2_IN_INDONESIA_MSK);
 		break;
@@ -828,14 +837,12 @@ __le32 iwl_acpi_get_lari_config_bitmap(struct iwl_fw_runtime *fwrt)
 	/*
 	 ** Evaluate func 'DSM_FUNC_DISABLE_SRD'
 	 */
-	ret = iwl_acpi_get_dsm_u8(fwrt->dev, 0,
-				  DSM_FUNC_DISABLE_SRD,
-				  &iwl_guid, &value);
+	ret = iwl_acpi_get_dsm(fwrt, DSM_FUNC_DISABLE_SRD, &val);
 	if (!ret) {
-		if (value == DSM_VALUE_SRD_PASSIVE)
+		if (val == DSM_VALUE_SRD_PASSIVE)
 			config_bitmap |=
 				cpu_to_le32(LARI_CONFIG_CHANGE_ETSI_TO_PASSIVE_MSK);
-		else if (value == DSM_VALUE_SRD_DISABLE)
+		else if (val == DSM_VALUE_SRD_DISABLE)
 			config_bitmap |=
 				cpu_to_le32(LARI_CONFIG_CHANGE_ETSI_TO_DISABLED_MSK);
 	}
@@ -845,9 +852,7 @@ __le32 iwl_acpi_get_lari_config_bitmap(struct iwl_fw_runtime *fwrt)
 		/*
 		 ** Evaluate func 'DSM_FUNC_REGULATORY_CONFIG'
 		 */
-		ret = iwl_acpi_get_dsm_u32(fwrt->dev, 0,
-					   DSM_FUNC_REGULATORY_CONFIG,
-					   &iwl_guid, &val);
+		ret = iwl_acpi_get_dsm(fwrt, DSM_FUNC_REGULATORY_CONFIG, &val);
 		/*
 		 * China 2022 enable if the BIOS object does not exist or
 		 * if it is enabled in BIOS.

drivers/net/wireless/intel/iwlwifi/fw/acpi.h

@@ -92,6 +92,8 @@
 /* The Inidcator whether UEFI WIFI GUID tables are locked is read from ACPI */
 #define UEFI_WIFI_GUID_UNLOCKED		0
 
+#define ACPI_DSM_REV 0
+
 enum iwl_dsm_funcs_rev_0 {
 	DSM_FUNC_QUERY = 0,
 	DSM_FUNC_DISABLE_SRD = 1,
@@ -103,7 +105,8 @@ enum iwl_dsm_funcs_rev_0 {
 	DSM_FUNC_ACTIVATE_CHANNEL = 8,
 	DSM_FUNC_FORCE_DISABLE_CHANNELS = 9,
 	DSM_FUNC_ENERGY_DETECTION_THRESHOLD = 10,
-	DSM_FUNC_RFI_CONFIG = 11
+	DSM_FUNC_RFI_CONFIG = 11,
+	DSM_FUNC_NUM_FUNCS = 12,
 };
 
 enum iwl_dsm_values_srd {
@@ -138,12 +141,6 @@ struct iwl_fw_runtime;
 
 extern const guid_t iwl_guid;
 
-int iwl_acpi_get_dsm_u8(struct device *dev, int rev, int func,
-			const guid_t *guid, u8 *value);
-
-int iwl_acpi_get_dsm_u32(struct device *dev, int rev, int func,
-			 const guid_t *guid, u32 *value);
-
 /**
  * iwl_acpi_get_mcc - read MCC from ACPI, if available
  *
@@ -185,6 +182,9 @@ void iwl_acpi_get_phy_filters(struct iwl_fw_runtime *fwrt,
 
 void iwl_acpi_get_guid_lock_status(struct iwl_fw_runtime *fwrt);
 
+int iwl_acpi_get_dsm(struct iwl_fw_runtime *fwrt,
+		     enum iwl_dsm_funcs_rev_0 func, u32 *value);
+
 #else /* CONFIG_ACPI */
 
 static inline void *iwl_acpi_get_dsm_object(struct device *dev, int rev,
@@ -193,18 +193,6 @@ 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,
-				      const guid_t *guid, u8 *value)
-{
-	return -ENOENT;
-}
-
-static inline int iwl_acpi_get_dsm_u32(struct device *dev, int rev, int func,
-				       const guid_t *guid, u32 *value)
-{
-	return -ENOENT;
-}
-
 static inline int iwl_acpi_get_mcc(struct iwl_fw_runtime *fwrt, char *mcc)
 {
 	return -ENOENT;
@@ -256,6 +244,13 @@ static inline void iwl_acpi_get_phy_filters(struct iwl_fw_runtime *fwrt,
 static inline void iwl_acpi_get_guid_lock_status(struct iwl_fw_runtime *fwrt)
 {
 }
+
+static inline int iwl_acpi_get_dsm(struct iwl_fw_runtime *fwrt,
+				   enum iwl_dsm_funcs_rev_0 func,
+				   u32 *value)
+{
+	return -ENOENT;
+}
 #endif /* CONFIG_ACPI */
 
 #endif /* __iwl_fw_acpi__ */

drivers/net/wireless/intel/iwlwifi/mvm/debugfs.c

@@ -391,9 +391,7 @@ static ssize_t iwl_dbgfs_wifi_6e_enable_read(struct file *file,
 	char buf[12];
 	u32 value;
 
-	err = iwl_acpi_get_dsm_u32(mvm->fwrt.dev, 0,
-				   DSM_FUNC_ENABLE_6E,
-				   &iwl_guid, &value);
+	err = iwl_acpi_get_dsm(&mvm->fwrt, DSM_FUNC_ENABLE_6E, &value);
 	if (err)
 		return err;
 

drivers/net/wireless/intel/iwlwifi/mvm/fw.c

@@ -1203,12 +1203,11 @@ static void iwl_mvm_tas_init(struct iwl_mvm *mvm)
 
 static bool iwl_mvm_eval_dsm_rfi(struct iwl_mvm *mvm)
 {
-	u8 value = 0;
+	u32 value = 0;
 	/* default behaviour is disabled */
 	bool bios_enable_rfi = false;
-	int ret  = iwl_acpi_get_dsm_u8(mvm->fwrt.dev, 0,
-				       DSM_FUNC_RFI_CONFIG, &iwl_guid,
-				       &value);
+	int ret = iwl_acpi_get_dsm(&mvm->fwrt, DSM_FUNC_RFI_CONFIG, &value);
+
 
 	if (ret < 0) {
 		IWL_DEBUG_RADIO(mvm, "Failed to get DSM RFI, ret=%d\n", ret);
@@ -1245,41 +1244,32 @@ static void iwl_mvm_lari_cfg(struct iwl_mvm *mvm)
 
 	cmd.config_bitmap = iwl_acpi_get_lari_config_bitmap(&mvm->fwrt);
 
-	ret = iwl_acpi_get_dsm_u32(mvm->fwrt.dev, 0, DSM_FUNC_11AX_ENABLEMENT,
-				   &iwl_guid, &value);
+	ret = iwl_acpi_get_dsm(&mvm->fwrt, DSM_FUNC_11AX_ENABLEMENT, &value);
 	if (!ret)
 		cmd.oem_11ax_allow_bitmap = cpu_to_le32(value);
 
-	ret = iwl_acpi_get_dsm_u32(mvm->fwrt.dev, 0,
-				   DSM_FUNC_ENABLE_UNII4_CHAN,
-				   &iwl_guid, &value);
+	ret = iwl_acpi_get_dsm(&mvm->fwrt, DSM_FUNC_ENABLE_UNII4_CHAN, &value);
 	if (!ret)
 		cmd.oem_unii4_allow_bitmap = cpu_to_le32(value);
 
-	ret = iwl_acpi_get_dsm_u32(mvm->fwrt.dev, 0,
-				   DSM_FUNC_ACTIVATE_CHANNEL,
-				   &iwl_guid, &value);
+	ret = iwl_acpi_get_dsm(&mvm->fwrt, DSM_FUNC_ACTIVATE_CHANNEL, &value);
 	if (!ret) {
 		if (cmd_ver < 8)
 			value &= ~ACTIVATE_5G2_IN_WW_MASK;
 		cmd.chan_state_active_bitmap = cpu_to_le32(value);
 	}
 
-	ret = iwl_acpi_get_dsm_u32(mvm->fwrt.dev, 0,
-				   DSM_FUNC_ENABLE_6E,
-				   &iwl_guid, &value);
+	ret = iwl_acpi_get_dsm(&mvm->fwrt, DSM_FUNC_ENABLE_6E, &value);
 	if (!ret)
 		cmd.oem_uhb_allow_bitmap = cpu_to_le32(value);
 
-	ret = iwl_acpi_get_dsm_u32(mvm->fwrt.dev, 0,
-				   DSM_FUNC_FORCE_DISABLE_CHANNELS,
-				   &iwl_guid, &value);
+	ret = iwl_acpi_get_dsm(&mvm->fwrt, DSM_FUNC_FORCE_DISABLE_CHANNELS,
+			       &value);
 	if (!ret)
 		cmd.force_disable_channels_bitmap = cpu_to_le32(value);
 
-	ret = iwl_acpi_get_dsm_u32(mvm->fwrt.dev, 0,
-				   DSM_FUNC_ENERGY_DETECTION_THRESHOLD,
-				   &iwl_guid, &value);
+	ret = iwl_acpi_get_dsm(&mvm->fwrt, DSM_FUNC_ENERGY_DETECTION_THRESHOLD,
+			       &value);
 	if (!ret)
 		cmd.edt_bitmap = cpu_to_le32(value);