iwlwifi: support SAR GEO Offset Mapping override via BIOS

Support reading the SAR Geographic Offset Mapping (SGOM) table from UEFI
to allow OEMs to override the values according to geographical regions.

Signed-off-by: Ayala Barazani <ayala.barazani@intel.com>
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>
Link: https://lore.kernel.org/r/iwlwifi.20211204174546.e6dfd8b5dd40.Ibc9a8fe2bfde345f49df5d57ec56663da6a53dc4@changeid
Signed-off-by: Luca Coelho <luciano.coelho@intel.com>

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

@@ -852,6 +852,8 @@ int iwl_sar_get_wgds_table(struct iwl_fw_runtime *fwrt)
 		}
 	}
 
+	fwrt->geo_num_profiles = num_profiles;
+	fwrt->geo_enabled = true;
 	ret = 0;
 out_free:
 	kfree(data);

drivers/net/wireless/intel/iwlwifi/fw/api/nvm-reg.h

@@ -33,6 +33,11 @@ enum iwl_regulatory_and_nvm_subcmd_ids {
 	 */
 	TAS_CONFIG = 0x3,
 
+	/**
+	 * @SAR_OFFSET_MAPPING_TABLE_CMD: &iwl_sar_offset_mapping_cmd
+	 */
+	SAR_OFFSET_MAPPING_TABLE_CMD = 0x4,
+
 	/**
 	 * @PNVM_INIT_COMPLETE_NTFY: &struct iwl_pnvm_init_complete_ntfy
 	 */

drivers/net/wireless/intel/iwlwifi/fw/api/power.h

@@ -503,6 +503,20 @@ union iwl_ppag_table_cmd {
 	} v2;
 } __packed;
 
+#define MCC_TO_SAR_OFFSET_TABLE_ROW_SIZE	26
+#define MCC_TO_SAR_OFFSET_TABLE_COL_SIZE	13
+
+/**
+ * struct iwl_sar_offset_mapping_cmd - struct for SAR_OFFSET_MAPPING_TABLE_CMD
+ * @offset_map: mapping a mcc to a geo sar group
+ * @reserved: reserved
+ */
+struct iwl_sar_offset_mapping_cmd {
+	u8 offset_map[MCC_TO_SAR_OFFSET_TABLE_ROW_SIZE]
+		[MCC_TO_SAR_OFFSET_TABLE_COL_SIZE];
+	u16 reserved;
+} __packed; /*SAR_OFFSET_MAPPING_TABLE_CMD_API_S*/
+
 /**
  * struct iwl_beacon_filter_cmd
  * REPLY_BEACON_FILTERING_CMD = 0xd2 (command)

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

@@ -156,8 +156,12 @@ struct iwl_fw_runtime {
 	u8 sar_chain_b_profile;
 	struct iwl_geo_profile geo_profiles[ACPI_NUM_GEO_PROFILES_REV3];
 	u32 geo_rev;
+	u32 geo_num_profiles;
+	bool geo_enabled;
 	union iwl_ppag_table_cmd ppag_table;
 	u32 ppag_ver;
+	struct iwl_sar_offset_mapping_cmd sgom_table;
+	bool sgom_enabled;
 #endif
 };
 

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

@@ -11,6 +11,7 @@
 #include "fw/uefi.h"
 #include "fw/api/alive.h"
 #include <linux/efi.h>
+#include "fw/runtime.h"
 
 #define IWL_EFI_VAR_GUID EFI_GUID(0x92daaf2f, 0xc02b, 0x455b,	\
 				  0xb2, 0xec, 0xf5, 0xa3,	\
@@ -260,3 +261,90 @@ void *iwl_uefi_get_reduced_power(struct iwl_trans *trans, size_t *len)
 
 	return data;
 }
+
+#ifdef CONFIG_ACPI
+static int iwl_uefi_sgom_parse(struct uefi_cnv_wlan_sgom_data *sgom_data,
+			       struct iwl_fw_runtime *fwrt)
+{
+	int i, j;
+
+	if (sgom_data->revision != 1)
+		return -EINVAL;
+
+	memcpy(fwrt->sgom_table.offset_map, sgom_data->offset_map,
+	       sizeof(fwrt->sgom_table.offset_map));
+
+	for (i = 0; i < MCC_TO_SAR_OFFSET_TABLE_ROW_SIZE; i++) {
+		for (j = 0; j < MCC_TO_SAR_OFFSET_TABLE_COL_SIZE; j++) {
+			/* since each byte is composed of to values, */
+			/* one for each letter, */
+			/* extract and check each of them separately */
+			u8 value = fwrt->sgom_table.offset_map[i][j];
+			u8 low = value & 0xF;
+			u8 high = (value & 0xF0) >> 4;
+
+			if (high > fwrt->geo_num_profiles)
+				high = 0;
+			if (low > fwrt->geo_num_profiles)
+				low = 0;
+			fwrt->sgom_table.offset_map[i][j] = (high << 4) | low;
+		}
+	}
+
+	fwrt->sgom_enabled = true;
+	return 0;
+}
+
+void iwl_uefi_get_sgom_table(struct iwl_trans *trans,
+			     struct iwl_fw_runtime *fwrt)
+{
+	struct efivar_entry *sgom_efivar;
+	struct uefi_cnv_wlan_sgom_data *data;
+	unsigned long package_size;
+	int err, ret;
+
+	if (!fwrt->geo_enabled)
+		return;
+
+	sgom_efivar = kzalloc(sizeof(*sgom_efivar), GFP_KERNEL);
+	if (!sgom_efivar)
+		return;
+
+	memcpy(&sgom_efivar->var.VariableName, IWL_UEFI_SGOM_NAME,
+	       sizeof(IWL_UEFI_SGOM_NAME));
+	sgom_efivar->var.VendorGuid = IWL_EFI_VAR_GUID;
+
+	/* TODO: we hardcode a maximum length here, because reading
+	 * from the UEFI is not working.  To implement this properly,
+	 * we have to call efivar_entry_size().
+	 */
+	package_size = IWL_HARDCODED_SGOM_SIZE;
+
+	data = kmalloc(package_size, GFP_KERNEL);
+	if (!data) {
+		data = ERR_PTR(-ENOMEM);
+		goto out;
+	}
+
+	err = efivar_entry_get(sgom_efivar, NULL, &package_size, data);
+	if (err) {
+		IWL_DEBUG_FW(trans,
+			     "SGOM UEFI variable not found %d\n", err);
+		goto out_free;
+	}
+
+	IWL_DEBUG_FW(trans, "Read SGOM from UEFI with size %lu\n",
+		     package_size);
+
+	ret = iwl_uefi_sgom_parse(data, fwrt);
+	if (ret < 0)
+		IWL_DEBUG_FW(trans, "Cannot read SGOM tables. rev is invalid\n");
+
+out_free:
+	kfree(data);
+
+out:
+	kfree(sgom_efivar);
+}
+IWL_EXPORT_SYMBOL(iwl_uefi_get_sgom_table);
+#endif /* CONFIG_ACPI */

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

@@ -7,6 +7,7 @@
 
 #define IWL_UEFI_OEM_PNVM_NAME		L"UefiCnvWlanOemSignedPnvm"
 #define IWL_UEFI_REDUCED_POWER_NAME	L"UefiCnvWlanReducedPower"
+#define IWL_UEFI_SGOM_NAME		L"UefiCnvWlanSarGeoOffsetMapping"
 
 /*
  * TODO: we have these hardcoded values that the caller must pass,
@@ -16,6 +17,7 @@
  */
 #define IWL_HARDCODED_PNVM_SIZE		4096
 #define IWL_HARDCODED_REDUCE_POWER_SIZE	32768
+#define IWL_HARDCODED_SGOM_SIZE		339
 
 struct pnvm_sku_package {
 	u8 rev;
@@ -25,6 +27,16 @@ struct pnvm_sku_package {
 	u8 data[];
 } __packed;
 
+struct uefi_cnv_wlan_sgom_data {
+	u8 revision;
+	u8 offset_map[IWL_HARDCODED_SGOM_SIZE - 1];
+} __packed;
+
+/*
+ * This is known to be broken on v4.19 and to work on v5.4.  Until we
+ * figure out why this is the case and how to make it work, simply
+ * disable the feature in old kernels.
+ */
 #ifdef CONFIG_EFI
 void *iwl_uefi_get_pnvm(struct iwl_trans *trans, size_t *len);
 void *iwl_uefi_get_reduced_power(struct iwl_trans *trans, size_t *len);
@@ -42,4 +54,12 @@ void *iwl_uefi_get_reduced_power(struct iwl_trans *trans, size_t *len)
 }
 #endif /* CONFIG_EFI */
 
+#if defined(CONFIG_EFI) && defined(CONFIG_ACPI)
+void iwl_uefi_get_sgom_table(struct iwl_trans *trans, struct iwl_fw_runtime *fwrt);
+#else
+static inline
+void iwl_uefi_get_sgom_table(struct iwl_trans *trans, struct iwl_fw_runtime *fwrt)
+{
+}
+#endif
 #endif /* __iwl_fw_uefi__ */

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

@@ -518,7 +518,6 @@ static void iwl_mvm_phy_filter_init(struct iwl_mvm *mvm,
 			cpu_to_le32(IWL_MVM_PHY_FILTER_CHAIN_D);
 	}
 }
-
 #else /* CONFIG_ACPI */
 
 static void iwl_mvm_phy_filter_init(struct iwl_mvm *mvm,
@@ -527,6 +526,49 @@ static void iwl_mvm_phy_filter_init(struct iwl_mvm *mvm,
 }
 #endif /* CONFIG_ACPI */
 
+#if defined(CONFIG_ACPI) && defined(CONFIG_EFI)
+static int iwl_mvm_sgom_init(struct iwl_mvm *mvm)
+{
+	u8 cmd_ver;
+	int ret;
+	struct iwl_host_cmd cmd = {
+		.id = WIDE_ID(REGULATORY_AND_NVM_GROUP,
+			      SAR_OFFSET_MAPPING_TABLE_CMD),
+		.flags = 0,
+		.data[0] = &mvm->fwrt.sgom_table,
+		.len[0] =  sizeof(mvm->fwrt.sgom_table),
+		.dataflags[0] = IWL_HCMD_DFL_NOCOPY,
+	};
+
+	if (!mvm->fwrt.sgom_enabled) {
+		IWL_DEBUG_RADIO(mvm, "SGOM table is disabled\n");
+		return 0;
+	}
+
+	cmd_ver = iwl_fw_lookup_cmd_ver(mvm->fw, REGULATORY_AND_NVM_GROUP,
+					SAR_OFFSET_MAPPING_TABLE_CMD,
+					IWL_FW_CMD_VER_UNKNOWN);
+
+	if (cmd_ver != 2) {
+		IWL_DEBUG_RADIO(mvm, "command version is unsupported. version = %d\n",
+				cmd_ver);
+		return 0;
+	}
+
+	ret = iwl_mvm_send_cmd(mvm, &cmd);
+	if (ret < 0)
+		IWL_ERR(mvm, "failed to send SAR_OFFSET_MAPPING_CMD (%d)\n", ret);
+
+	return ret;
+}
+#else
+
+static int iwl_mvm_sgom_init(struct iwl_mvm *mvm)
+{
+	return 0;
+}
+#endif
+
 static int iwl_send_phy_cfg_cmd(struct iwl_mvm *mvm)
 {
 	struct iwl_phy_cfg_cmd_v3 phy_cfg_cmd;
@@ -1340,6 +1382,7 @@ static u8 iwl_mvm_eval_dsm_rfi(struct iwl_mvm *mvm)
 void iwl_mvm_get_acpi_tables(struct iwl_mvm *mvm)
 {
 }
+
 #endif /* CONFIG_ACPI */
 
 void iwl_mvm_send_recovery_cmd(struct iwl_mvm *mvm, u32 flags)
@@ -1634,6 +1677,10 @@ int iwl_mvm_up(struct iwl_mvm *mvm)
 	else if (ret < 0)
 		goto error;
 
+	ret = iwl_mvm_sgom_init(mvm);
+	if (ret)
+		goto error;
+
 	iwl_mvm_tas_init(mvm);
 	iwl_mvm_leds_sync(mvm);
 

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

@@ -26,6 +26,7 @@
 #include "time-event.h"
 #include "fw-api.h"
 #include "fw/acpi.h"
+#include "fw/uefi.h"
 
 #define DRV_DESCRIPTION	"The new Intel(R) wireless AGN driver for Linux"
 MODULE_DESCRIPTION(DRV_DESCRIPTION);
@@ -1094,6 +1095,7 @@ iwl_op_mode_mvm_start(struct iwl_trans *trans, const struct iwl_cfg *cfg,
 			    &iwl_mvm_sanitize_ops, mvm, dbgfs_dir);
 
 	iwl_mvm_get_acpi_tables(mvm);
+	iwl_uefi_get_sgom_table(trans, &mvm->fwrt);
 
 	mvm->init_status = 0;