// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright (C) 2013, 2014 Linaro Ltd;  <roy.franz@linaro.org>
 *
 * This file implements the EFI boot stub for the arm64 kernel.
 * Adapted from ARM version by Mark Salter <msalter@redhat.com>
 */


#include <linux/efi.h>
#include <asm/efi.h>
#include <asm/memory.h>
#include <asm/sysreg.h>

#include "efistub.h"

static bool system_needs_vamap(void)
{
	const struct efi_smbios_type4_record *record;
	const u32 __aligned(1) *socid;
	const u8 *version;

	/*
	 * Ampere eMAG, Altra, and Altra Max machines crash in SetTime() if
	 * SetVirtualAddressMap() has not been called prior. Most Altra systems
	 * can be identified by the SMCCC soc ID, which is conveniently exposed
	 * via the type 4 SMBIOS records. Otherwise, test the processor version
	 * field. eMAG systems all appear to have the processor version field
	 * set to "eMAG".
	 */
	record = (struct efi_smbios_type4_record *)efi_get_smbios_record(4);
	if (!record)
		return false;

	socid = (u32 *)record->processor_id;
	switch (*socid & 0xffff000f) {
		static char const altra[] = "Ampere(TM) Altra(TM) Processor";
		static char const emag[] = "eMAG";

	default:
		version = efi_get_smbios_string(&record->header, 4,
						processor_version);
		if (!version || (strncmp(version, altra, sizeof(altra) - 1) &&
				 strncmp(version, emag, sizeof(emag) - 1)))
			break;

		fallthrough;

	case 0x0a160001:	// Altra
	case 0x0a160002:	// Altra Max
		efi_warn("Working around broken SetVirtualAddressMap()\n");
		return true;
	}

	return false;
}

efi_status_t check_platform_features(void)
{
	u64 tg;

	/*
	 * If we have 48 bits of VA space for TTBR0 mappings, we can map the
	 * UEFI runtime regions 1:1 and so calling SetVirtualAddressMap() is
	 * unnecessary.
	 */
	if (VA_BITS_MIN >= 48 && !system_needs_vamap())
		efi_novamap = true;

	/* UEFI mandates support for 4 KB granularity, no need to check */
	if (IS_ENABLED(CONFIG_ARM64_4K_PAGES))
		return EFI_SUCCESS;

	tg = (read_cpuid(ID_AA64MMFR0_EL1) >> ID_AA64MMFR0_EL1_TGRAN_SHIFT) & 0xf;
	if (tg < ID_AA64MMFR0_EL1_TGRAN_SUPPORTED_MIN || tg > ID_AA64MMFR0_EL1_TGRAN_SUPPORTED_MAX) {
		if (IS_ENABLED(CONFIG_ARM64_64K_PAGES))
			efi_err("This 64 KB granular kernel is not supported by your CPU\n");
		else
			efi_err("This 16 KB granular kernel is not supported by your CPU\n");
		return EFI_UNSUPPORTED;
	}
	return EFI_SUCCESS;
}

void efi_cache_sync_image(unsigned long image_base,
			  unsigned long alloc_size,
			  unsigned long code_size)
{
	u32 ctr = read_cpuid_effective_cachetype();
	u64 lsize = 4 << cpuid_feature_extract_unsigned_field(ctr,
						CTR_EL0_DminLine_SHIFT);

	do {
		asm("dc civac, %0" :: "r"(image_base));
		image_base += lsize;
		alloc_size -= lsize;
	} while (alloc_size >= lsize);

	asm("ic ialluis");
	dsb(ish);
	isb();
}