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

// SPDX-License-Identifier: GPL-2.0 OR BSD-3-Clause
/*
 * Copyright(c) 2021 Intel Corporation
 */

#include "iwl-drv.h"
#include "pnvm.h"
#include "iwl-prph.h"
#include "iwl-io.h"

#include "fw/uefi.h"
#include "fw/api/alive.h"
#include <linux/efi.h>

#define IWL_EFI_VAR_GUID EFI_GUID(0x92daaf2f, 0xc02b, 0x455b,	\
				  0xb2, 0xec, 0xf5, 0xa3,	\
				  0x59, 0x4f, 0x4a, 0xea)

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;

	*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;

	/*
	 * 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;

	data = kmalloc(package_size, GFP_KERNEL);
	if (!data) {
		data = ERR_PTR(-ENOMEM);
		goto out;
	}

	err = efivar_entry_get(pnvm_efivar, NULL, &package_size, data);
	if (err) {
		IWL_DEBUG_FW(trans,
			     "PNVM UEFI variable not found %d (len %lu)\n",
			     err, package_size);
		kfree(data);
		data = ERR_PTR(err);
		goto out;
	}

	IWL_DEBUG_FW(trans, "Read PNVM from UEFI with size %lu\n", package_size);
	*len = package_size;

out:
	kfree(pnvm_efivar);

	return data;
}

static void *iwl_uefi_reduce_power_section(struct iwl_trans *trans,
					   const u8 *data, size_t len)
{
	struct iwl_ucode_tlv *tlv;
	u8 *reduce_power_data = NULL, *tmp;
	u32 size = 0;

	IWL_DEBUG_FW(trans, "Handling REDUCE_POWER section\n");

	while (len >= sizeof(*tlv)) {
		u32 tlv_len, tlv_type;

		len -= sizeof(*tlv);
		tlv = (void *)data;

		tlv_len = le32_to_cpu(tlv->length);
		tlv_type = le32_to_cpu(tlv->type);

		if (len < tlv_len) {
			IWL_ERR(trans, "invalid TLV len: %zd/%u\n",
				len, tlv_len);
			kfree(reduce_power_data);
			reduce_power_data = ERR_PTR(-EINVAL);
			goto out;
		}

		data += sizeof(*tlv);

		switch (tlv_type) {
		case IWL_UCODE_TLV_MEM_DESC: {
			IWL_DEBUG_FW(trans,
				     "Got IWL_UCODE_TLV_MEM_DESC len %d\n",
				     tlv_len);

			IWL_DEBUG_FW(trans, "Adding data (size %d)\n", tlv_len);

			tmp = krealloc(reduce_power_data, size + tlv_len, GFP_KERNEL);
			if (!tmp) {
				IWL_DEBUG_FW(trans,
					     "Couldn't allocate (more) reduce_power_data\n");

				kfree(reduce_power_data);
				reduce_power_data = ERR_PTR(-ENOMEM);
				goto out;
			}

			reduce_power_data = tmp;

			memcpy(reduce_power_data + size, data, tlv_len);

			size += tlv_len;

			break;
		}
		case IWL_UCODE_TLV_PNVM_SKU:
			IWL_DEBUG_FW(trans,
				     "New REDUCE_POWER section started, stop parsing.\n");
			goto done;
		default:
			IWL_DEBUG_FW(trans, "Found TLV 0x%0x, len %d\n",
				     tlv_type, tlv_len);
			break;
		}

		len -= ALIGN(tlv_len, 4);
		data += ALIGN(tlv_len, 4);
	}

done:
	if (!size) {
		IWL_DEBUG_FW(trans, "Empty REDUCE_POWER, skipping.\n");
		/* Better safe than sorry, but 'reduce_power_data' should
		 * always be NULL if !size.
		 */
		kfree(reduce_power_data);
		reduce_power_data = ERR_PTR(-ENOENT);
		goto out;
	}

	IWL_INFO(trans, "loaded REDUCE_POWER\n");

out:
	return reduce_power_data;
}

static void *iwl_uefi_reduce_power_parse(struct iwl_trans *trans,
					 const u8 *data, size_t len)
{
	struct iwl_ucode_tlv *tlv;
	void *sec_data;

	IWL_DEBUG_FW(trans, "Parsing REDUCE_POWER data\n");

	while (len >= sizeof(*tlv)) {
		u32 tlv_len, tlv_type;

		len -= sizeof(*tlv);
		tlv = (void *)data;

		tlv_len = le32_to_cpu(tlv->length);
		tlv_type = le32_to_cpu(tlv->type);

		if (len < tlv_len) {
			IWL_ERR(trans, "invalid TLV len: %zd/%u\n",
				len, tlv_len);
			return ERR_PTR(-EINVAL);
		}

		if (tlv_type == IWL_UCODE_TLV_PNVM_SKU) {
			struct iwl_sku_id *sku_id =
				(void *)(data + sizeof(*tlv));

			IWL_DEBUG_FW(trans,
				     "Got IWL_UCODE_TLV_PNVM_SKU len %d\n",
				     tlv_len);
			IWL_DEBUG_FW(trans, "sku_id 0x%0x 0x%0x 0x%0x\n",
				     le32_to_cpu(sku_id->data[0]),
				     le32_to_cpu(sku_id->data[1]),
				     le32_to_cpu(sku_id->data[2]));

			data += sizeof(*tlv) + ALIGN(tlv_len, 4);
			len -= ALIGN(tlv_len, 4);

			if (trans->sku_id[0] == le32_to_cpu(sku_id->data[0]) &&
			    trans->sku_id[1] == le32_to_cpu(sku_id->data[1]) &&
			    trans->sku_id[2] == le32_to_cpu(sku_id->data[2])) {
				sec_data = iwl_uefi_reduce_power_section(trans,
									 data,
									 len);
				if (!IS_ERR(sec_data))
					return sec_data;
			} else {
				IWL_DEBUG_FW(trans, "SKU ID didn't match!\n");
			}
		} else {
			data += sizeof(*tlv) + ALIGN(tlv_len, 4);
			len -= ALIGN(tlv_len, 4);
		}
	}

	return ERR_PTR(-ENOENT);
}

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;

	*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;

	/*
	 * 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_REDUCE_POWER_SIZE;

	package = kmalloc(package_size, GFP_KERNEL);
	if (!package) {
		package = ERR_PTR(-ENOMEM);
		goto out;
	}

	err = efivar_entry_get(reduce_power_efivar, NULL, &package_size, package);
	if (err) {
		IWL_DEBUG_FW(trans,
			     "Reduced Power UEFI variable not found %d (len %lu)\n",
			     err, package_size);
		kfree(package);
		data = ERR_PTR(err);
		goto out;
	}

	IWL_DEBUG_FW(trans, "Read reduced power from UEFI with size %lu\n",
		     package_size);
	*len = package_size;

	IWL_DEBUG_FW(trans, "rev %d, total_size %d, n_skus %d\n",
		     package->rev, package->total_size, package->n_skus);

	data = iwl_uefi_reduce_power_parse(trans, package->data,
					   *len - sizeof(*package));

	kfree(package);

out:
	kfree(reduce_power_efivar);

	return data;
}