brcmfmac: Switch to appropriate helper to load EFI variable contents

Avoid abusing the efivar layer by invoking it with locally constructed
efivar_entry instances, and instead, just call the EFI routines directly
if available.

Acked-by: Kalle Valo <kvalo@kernel.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>

diff --git a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/firmware.c b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/firmware.c
index dcbe55b..b8379e4 100644 (file)
--- a/drivers/net/wireless/broadcom/brcm80211/brcmfmac/firmware.c
+++ b/drivers/net/wireless/broadcom/brcm80211/brcmfmac/firmware.c
@@ -459,43 +459,34 @@ static void brcmf_fw_fix_efi_nvram_ccode(char *data, unsigned long data_len)
 
 static u8 *brcmf_fw_nvram_from_efi(size_t *data_len_ret)
 {
-       const u16 name[] = { 'n', 'v', 'r', 'a', 'm', 0 };
-       struct efivar_entry *nvram_efivar;
+       efi_guid_t guid = EFI_GUID(0x74b00bd9, 0x805a, 0x4d61, 0xb5, 0x1f,
+                                  0x43, 0x26, 0x81, 0x23, 0xd1, 0x13);
        unsigned long data_len = 0;
+       efi_status_t status;
        u8 *data = NULL;
-       int err;
 
-       nvram_efivar = kzalloc(sizeof(*nvram_efivar), GFP_KERNEL);
-       if (!nvram_efivar)
+       if (!efi_rt_services_supported(EFI_RT_SUPPORTED_GET_VARIABLE))
                return NULL;
 
-       memcpy(&nvram_efivar->var.VariableName, name, sizeof(name));
-       nvram_efivar->var.VendorGuid = EFI_GUID(0x74b00bd9, 0x805a, 0x4d61,
-                                               0xb5, 0x1f, 0x43, 0x26,
-                                               0x81, 0x23, 0xd1, 0x13);
-
-       err = efivar_entry_size(nvram_efivar, &data_len);
-       if (err)
+       status = efi.get_variable(L"nvram", &guid, NULL, &data_len, NULL);
+       if (status != EFI_BUFFER_TOO_SMALL)
                goto fail;
 
        data = kmalloc(data_len, GFP_KERNEL);
        if (!data)
                goto fail;
 
-       err = efivar_entry_get(nvram_efivar, NULL, &data_len, data);
-       if (err)
+       status = efi.get_variable(L"nvram", &guid, NULL, &data_len, data);
+       if (status != EFI_SUCCESS)
                goto fail;
 
        brcmf_fw_fix_efi_nvram_ccode(data, data_len);
        brcmf_info("Using nvram EFI variable\n");
 
-       kfree(nvram_efivar);
        *data_len_ret = data_len;
        return data;
-
 fail:
        kfree(data);
-       kfree(nvram_efivar);
        return NULL;
 }
 #else