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@changeid
Signed-off-by: Johannes Berg <johannes.berg@intel.com>

1 files changed, 47 insertions, 42 deletions

diff --git a/drivers/net/wireless/intel/iwlwifi/fw/acpi.c b/drivers/net/wireless/intel/iwlwifi/fw/acpi.c
index 6f9ead79978a..22b21bbc294f 100644
--- a/drivers/net/wireless/intel/iwlwifi/fw/acpi.c
+++ b/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 @@ out:
 }
 
 /*
- * 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 @@ out_free:
 __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.