From: Luca Coelho <luciano.coelho@xxxxxxxxx>
We now support fetching the PNVM data from a UEFI variable. Add the
code to read this variable first and use it. If it's not available,
we fall back to reading the data from the filesystem, as before.
Signed-off-by: Luca Coelho <luciano.coelho@xxxxxxxxx>
---
drivers/net/wireless/intel/iwlwifi/fw/pnvm.c | 91 +++++++++++++++++++-
1 file changed, 90 insertions(+), 1 deletion(-)
diff --git a/drivers/net/wireless/intel/iwlwifi/fw/pnvm.c b/drivers/net/wireless/intel/iwlwifi/fw/pnvm.c
index d515af8c1686..2cd07d2690e0 100644
--- a/drivers/net/wireless/intel/iwlwifi/fw/pnvm.c
+++ b/drivers/net/wireless/intel/iwlwifi/fw/pnvm.c
@@ -10,6 +10,7 @@
#include "fw/api/commands.h"
#include "fw/api/nvm-reg.h"
#include "fw/api/alive.h"
+#include <linux/efi.h>
struct iwl_pnvm_section {
__le32 offset;
@@ -219,6 +220,88 @@ static int iwl_pnvm_parse(struct iwl_trans *trans, const u8 *data,
return -ENOENT;
}
+/*
+ * 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.
+ */
+#if defined(CONFIG_EFI)
+
+#define IWL_EFI_VAR_GUID EFI_GUID(0x92daaf2f, 0xc02b, 0x455b, \
+ 0xb2, 0xec, 0xf5, 0xa3, \
+ 0x59, 0x4f, 0x4a, 0xea)
+
+#define IWL_UEFI_OEM_PNVM_NAME L"UefiCnvWlanOemSignedPnvm"
+
+#define IWL_HARDCODED_PNVM_SIZE 4096
+
+struct pnvm_sku_package {
+ u8 rev;
+ u8 reserved1[3];
+ u32 total_size;
+ u8 n_skus;
+ u8 reserved2[11];
+ u8 data[];
+};
+
+static int iwl_pnvm_get_from_efi(struct iwl_trans *trans,
+ u8 **data, size_t *len)
+{
+ struct efivar_entry *pnvm_efivar;
+ struct pnvm_sku_package *package;
+ unsigned long package_size;
+ int err;
+
+ pnvm_efivar = kzalloc(sizeof(*pnvm_efivar), GFP_KERNEL);
+ if (!pnvm_efivar)
+ return -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;
+
+ /*
+ * 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_PNVM_SIZE;
+
+ package = kmalloc(package_size, GFP_KERNEL);
+ if (!package) {
+ err = -ENOMEM;
+ goto out;
+ }
+
+ err = efivar_entry_get(pnvm_efivar, NULL, &package_size, package);
+ if (err) {
+ IWL_DEBUG_FW(trans,
+ "PNVM UEFI variable not found %d (len %zd)\n",
+ err, package_size);
+ goto out;
+ }
+
+ IWL_DEBUG_FW(trans, "Read PNVM fro UEFI with size %zd\n", package_size);
+
+ *data = kmemdup(package->data, *len, GFP_KERNEL);
+ if (!*data)
+ err = -ENOMEM;
+ *len = package_size - sizeof(*package);
+
+out:
+ kfree(package);
+ kfree(pnvm_efivar);
+
+ return err;
+}
+#else /* CONFIG_EFI */
+static inline int iwl_pnvm_get_from_efi(struct iwl_trans *trans,
+ u8 **data, size_t *len)
+{
+ return -EOPNOTSUPP;
+}
+#endif /* CONFIG_EFI */
+
static int iwl_pnvm_get_from_fs(struct iwl_trans *trans, u8 **data, size_t *len)
{
const struct firmware *pnvm;
@@ -277,7 +360,12 @@ int iwl_pnvm_load(struct iwl_trans *trans,
goto skip_parse;
}
- /* Try to load the PNVM from the filesystem */
+ /* First attempt to get the PNVM from BIOS */
+ ret = iwl_pnvm_get_from_efi(trans, &data, &len);
+ if (!ret)
+ goto parse;
+
+ /* If it's not available, try from the filesystem */
ret = iwl_pnvm_get_from_fs(trans, &data, &len);
if (ret) {
/*
@@ -290,6 +378,7 @@ int iwl_pnvm_load(struct iwl_trans *trans,
goto skip_parse;
}
+parse:
iwl_pnvm_parse(trans, data, len);
kfree(data);
--
2.30.0
