141 lines
3.7 KiB
C
141 lines
3.7 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright (C) 2013, 2014 Linaro Ltd; <roy.franz@linaro.org>
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*
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* This file implements the EFI boot stub for the arm64 kernel.
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* Adapted from ARM version by Mark Salter <msalter@redhat.com>
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*/
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#include <linux/efi.h>
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#include <asm/efi.h>
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#include <asm/image.h>
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#include <asm/memory.h>
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#include <asm/sysreg.h>
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#include "efistub.h"
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static bool system_needs_vamap(void)
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{
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const struct efi_smbios_type4_record *record;
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const u32 __aligned(1) *socid;
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const u8 *version;
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/*
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* Ampere eMAG, Altra, and Altra Max machines crash in SetTime() if
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* SetVirtualAddressMap() has not been called prior. Most Altra systems
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* can be identified by the SMCCC soc ID, which is conveniently exposed
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* via the type 4 SMBIOS records. Otherwise, test the processor version
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* field. eMAG systems all appear to have the processor version field
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* set to "eMAG".
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*/
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record = (struct efi_smbios_type4_record *)efi_get_smbios_record(4);
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if (!record)
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return false;
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socid = (u32 *)record->processor_id;
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switch (*socid & 0xffff000f) {
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static char const altra[] = "Ampere(TM) Altra(TM) Processor";
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static char const emag[] = "eMAG";
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default:
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version = efi_get_smbios_string(&record->header, 4,
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processor_version);
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if (!version || (strncmp(version, altra, sizeof(altra) - 1) &&
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strncmp(version, emag, sizeof(emag) - 1)))
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break;
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fallthrough;
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case 0x0a160001: // Altra
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case 0x0a160002: // Altra Max
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efi_warn("Working around broken SetVirtualAddressMap()\n");
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return true;
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}
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return false;
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}
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efi_status_t check_platform_features(void)
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{
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u64 tg;
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/*
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* If we have 48 bits of VA space for TTBR0 mappings, we can map the
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* UEFI runtime regions 1:1 and so calling SetVirtualAddressMap() is
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* unnecessary.
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*/
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if (VA_BITS_MIN >= 48 && !system_needs_vamap())
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efi_novamap = true;
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/* UEFI mandates support for 4 KB granularity, no need to check */
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if (IS_ENABLED(CONFIG_ARM64_4K_PAGES))
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return EFI_SUCCESS;
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tg = (read_cpuid(ID_AA64MMFR0_EL1) >> ID_AA64MMFR0_EL1_TGRAN_SHIFT) & 0xf;
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if (tg < ID_AA64MMFR0_EL1_TGRAN_SUPPORTED_MIN || tg > ID_AA64MMFR0_EL1_TGRAN_SUPPORTED_MAX) {
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if (IS_ENABLED(CONFIG_ARM64_64K_PAGES))
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efi_err("This 64 KB granular kernel is not supported by your CPU\n");
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else
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efi_err("This 16 KB granular kernel is not supported by your CPU\n");
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return EFI_UNSUPPORTED;
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}
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return EFI_SUCCESS;
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}
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#ifdef CONFIG_ARM64_WORKAROUND_CLEAN_CACHE
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#define DCTYPE "civac"
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#else
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#define DCTYPE "cvau"
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#endif
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u32 __weak code_size;
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void efi_cache_sync_image(unsigned long image_base,
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unsigned long alloc_size)
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{
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u32 ctr = read_cpuid_effective_cachetype();
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u64 lsize = 4 << cpuid_feature_extract_unsigned_field(ctr,
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CTR_EL0_DminLine_SHIFT);
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/* only perform the cache maintenance if needed for I/D coherency */
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if (!(ctr & BIT(CTR_EL0_IDC_SHIFT))) {
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unsigned long base = image_base;
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unsigned long size = code_size;
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do {
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asm("dc " DCTYPE ", %0" :: "r"(base));
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base += lsize;
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size -= lsize;
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} while (size >= lsize);
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}
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asm("ic ialluis");
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dsb(ish);
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isb();
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efi_remap_image(image_base, alloc_size, code_size);
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}
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unsigned long __weak primary_entry_offset(void)
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{
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/*
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* By default, we can invoke the kernel via the branch instruction in
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* the image header, so offset #0. This will be overridden by the EFI
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* stub build that is linked into the core kernel, as in that case, the
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* image header may not have been loaded into memory, or may be mapped
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* with non-executable permissions.
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*/
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return 0;
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}
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void __noreturn efi_enter_kernel(unsigned long entrypoint,
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unsigned long fdt_addr,
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unsigned long fdt_size)
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{
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void (* __noreturn enter_kernel)(u64, u64, u64, u64);
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enter_kernel = (void *)entrypoint + primary_entry_offset();
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enter_kernel(fdt_addr, 0, 0, 0);
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}
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