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From:   Ard Biesheuvel <ardb@kernel.org>
To:     linux-efi@vger.kernel.org
Cc:     keescook@chromium.org, Ard Biesheuvel <ardb@kernel.org>,
        Dmitry Torokhov <dmitry.torokhov@gmail.com>,
        Arend van Spriel <aspriel@gmail.com>,
        Franky Lin <franky.lin@broadcom.com>,
        Hante Meuleman <hante.meuleman@broadcom.com>,
        Kalle Valo <kvalo@kernel.org>,
        "David S. Miller" <davem@davemloft.net>,
        Eric Dumazet <edumazet@google.com>,
        Jakub Kicinski <kuba@kernel.org>,
        Paolo Abeni <pabeni@redhat.com>,
        Gregory Greenman <gregory.greenman@intel.com>,
        linux-input@vger.kernel.org, linux-wireless@vger.kernel.org,
        brcm80211-dev-list.pdl@broadcom.com
Subject: [PATCH 3/4] iwlwifi: Switch to proper EFI variable store interface
Date:   Fri, 17 Jun 2022 19:48:50 +0200
Message-Id: <20220617174851.1286026-4-ardb@kernel.org>
In-Reply-To: <20220617174851.1286026-1-ardb@kernel.org>
References: <20220617174851.1286026-1-ardb@kernel.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Using half of the efivar API with locally baked efivar_entry instances
is not the right way to use this API, and these uses impede planned work
on the efivar layer itself.

So switch to direct EFI variable store accesses: we don't need the
efivar layer anyway.

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
---
 drivers/net/wireless/intel/iwlwifi/fw/uefi.c | 96 +++++++-------------
 1 file changed, 32 insertions(+), 64 deletions(-)

diff --git a/drivers/net/wireless/intel/iwlwifi/fw/uefi.c b/drivers/net/wireless/intel/iwlwifi/fw/uefi.c
index 23b1d689ba7b..9854466c21d9 100644
--- a/drivers/net/wireless/intel/iwlwifi/fw/uefi.c
+++ b/drivers/net/wireless/intel/iwlwifi/fw/uefi.c
@@ -19,20 +19,14 @@
 
 void *iwl_uefi_get_pnvm(struct iwl_trans *trans, size_t *len)
 {
-	struct efivar_entry *pnvm_efivar;
 	void *data;
 	unsigned long package_size;
-	int err;
+	efi_status_t status;
 
 	*len = 0;
 
-	pnvm_efivar = kzalloc(sizeof(*pnvm_efivar), GFP_KERNEL);
-	if (!pnvm_efivar)
-		return ERR_PTR(-ENOMEM);
-
-	memcpy(&pnvm_efivar->var.VariableName, IWL_UEFI_OEM_PNVM_NAME,
-	       sizeof(IWL_UEFI_OEM_PNVM_NAME));
-	pnvm_efivar->var.VendorGuid = IWL_EFI_VAR_GUID;
+	if (!efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE))
+		return ERR_PTR(-ENODEV);
 
 	/*
 	 * TODO: we hardcode a maximum length here, because reading
@@ -42,27 +36,22 @@ void *iwl_uefi_get_pnvm(struct iwl_trans *trans, size_t *len)
 	package_size = IWL_HARDCODED_PNVM_SIZE;
 
 	data = kmalloc(package_size, GFP_KERNEL);
-	if (!data) {
-		data = ERR_PTR(-ENOMEM);
-		goto out;
-	}
+	if (!data)
+		return ERR_PTR(-ENOMEM);
 
-	err = efivar_entry_get(pnvm_efivar, NULL, &package_size, data);
-	if (err) {
+	status = efi.get_variable(IWL_UEFI_OEM_PNVM_NAME, &IWL_EFI_VAR_GUID,
+				  NULL, &package_size, data);
+	if (status != EFI_SUCCESS) {
 		IWL_DEBUG_FW(trans,
-			     "PNVM UEFI variable not found %d (len %lu)\n",
-			     err, package_size);
+			     "PNVM UEFI variable not found 0x%lx (len %lu)\n",
+			     status, package_size);
 		kfree(data);
-		data = ERR_PTR(err);
-		goto out;
+		return ERR_PTR(efi_status_to_err(status));
 	}
 
 	IWL_DEBUG_FW(trans, "Read PNVM from UEFI with size %lu\n", package_size);
 	*len = package_size;
 
-out:
-	kfree(pnvm_efivar);
-
 	return data;
 }
 
@@ -211,21 +200,15 @@ static void *iwl_uefi_reduce_power_parse(struct iwl_trans *trans,
 
 void *iwl_uefi_get_reduced_power(struct iwl_trans *trans, size_t *len)
 {
-	struct efivar_entry *reduce_power_efivar;
 	struct pnvm_sku_package *package;
 	void *data = NULL;
 	unsigned long package_size;
-	int err;
+	efi_status_t status;
 
 	*len = 0;
 
-	reduce_power_efivar = kzalloc(sizeof(*reduce_power_efivar), GFP_KERNEL);
-	if (!reduce_power_efivar)
-		return ERR_PTR(-ENOMEM);
-
-	memcpy(&reduce_power_efivar->var.VariableName, IWL_UEFI_REDUCED_POWER_NAME,
-	       sizeof(IWL_UEFI_REDUCED_POWER_NAME));
-	reduce_power_efivar->var.VendorGuid = IWL_EFI_VAR_GUID;
+	if (!efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE))
+		return ERR_PTR(-ENODEV);
 
 	/*
 	 * TODO: we hardcode a maximum length here, because reading
@@ -235,19 +218,17 @@ void *iwl_uefi_get_reduced_power(struct iwl_trans *trans, size_t *len)
 	package_size = IWL_HARDCODED_REDUCE_POWER_SIZE;
 
 	package = kmalloc(package_size, GFP_KERNEL);
-	if (!package) {
-		package = ERR_PTR(-ENOMEM);
-		goto out;
-	}
+	if (!package)
+		return ERR_PTR(-ENOMEM);
 
-	err = efivar_entry_get(reduce_power_efivar, NULL, &package_size, package);
-	if (err) {
+	status = efi.get_variable(IWL_UEFI_REDUCED_POWER_NAME, &IWL_EFI_VAR_GUID,
+				  NULL, &package_size, data);
+	if (status != EFI_SUCCESS) {
 		IWL_DEBUG_FW(trans,
-			     "Reduced Power UEFI variable not found %d (len %lu)\n",
-			     err, package_size);
+			     "Reduced Power UEFI variable not found 0x%lx (len %lu)\n",
+			     status, package_size);
 		kfree(package);
-		data = ERR_PTR(err);
-		goto out;
+		return ERR_PTR(efi_status_to_err(status));
 	}
 
 	IWL_DEBUG_FW(trans, "Read reduced power from UEFI with size %lu\n",
@@ -262,9 +243,6 @@ void *iwl_uefi_get_reduced_power(struct iwl_trans *trans, size_t *len)
 
 	kfree(package);
 
-out:
-	kfree(reduce_power_efivar);
-
 	return data;
 }
 
@@ -304,22 +282,15 @@ static int iwl_uefi_sgom_parse(struct uefi_cnv_wlan_sgom_data *sgom_data,
 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;
+	efi_status_t status;
+	int ret;
 
-	sgom_efivar = kzalloc(sizeof(*sgom_efivar), GFP_KERNEL);
-	if (!sgom_efivar)
+	if (!fwrt->geo_enabled ||
+	    !efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE))
 		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().
@@ -327,15 +298,14 @@ void iwl_uefi_get_sgom_table(struct iwl_trans *trans,
 	package_size = IWL_HARDCODED_SGOM_SIZE;
 
 	data = kmalloc(package_size, GFP_KERNEL);
-	if (!data) {
-		data = ERR_PTR(-ENOMEM);
-		goto out;
-	}
+	if (!data)
+		return;
 
-	err = efivar_entry_get(sgom_efivar, NULL, &package_size, data);
-	if (err) {
+	status = efi.get_variable(IWL_UEFI_SGOM_NAME, &IWL_EFI_VAR_GUID,
+				  NULL, &package_size, data);
+	if (status != EFI_SUCCESS) {
 		IWL_DEBUG_FW(trans,
-			     "SGOM UEFI variable not found %d\n", err);
+			     "SGOM UEFI variable not found 0x%lx\n", status);
 		goto out_free;
 	}
 
@@ -349,8 +319,6 @@ void iwl_uefi_get_sgom_table(struct iwl_trans *trans,
 out_free:
 	kfree(data);
 
-out:
-	kfree(sgom_efivar);
 }
 IWL_EXPORT_SYMBOL(iwl_uefi_get_sgom_table);
 #endif /* CONFIG_ACPI */
-- 
2.35.1