144 lines
3.1 KiB
C
144 lines
3.1 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Extensible Firmware Interface
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*
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* Copyright (C) 2020 Western Digital Corporation or its affiliates.
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*
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* Based on Extensible Firmware Interface Specification version 2.4
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* Adapted from drivers/firmware/efi/arm-runtime.c
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*
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*/
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#include <linux/dmi.h>
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#include <linux/efi.h>
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#include <linux/io.h>
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#include <linux/memblock.h>
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#include <linux/mm_types.h>
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#include <linux/preempt.h>
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#include <linux/rbtree.h>
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#include <linux/rwsem.h>
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <linux/spinlock.h>
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#include <linux/pgtable.h>
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#include <asm/cacheflush.h>
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#include <asm/efi.h>
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#include <asm/mmu.h>
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#include <asm/pgalloc.h>
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static bool __init efi_virtmap_init(void)
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{
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efi_memory_desc_t *md;
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efi_mm.pgd = pgd_alloc(&efi_mm);
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mm_init_cpumask(&efi_mm);
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init_new_context(NULL, &efi_mm);
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for_each_efi_memory_desc(md) {
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phys_addr_t phys = md->phys_addr;
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int ret;
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if (!(md->attribute & EFI_MEMORY_RUNTIME))
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continue;
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if (md->virt_addr == 0)
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return false;
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ret = efi_create_mapping(&efi_mm, md);
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if (ret) {
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pr_warn(" EFI remap %pa: failed to create mapping (%d)\n",
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&phys, ret);
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return false;
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}
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}
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if (efi_memattr_apply_permissions(&efi_mm, efi_set_mapping_permissions))
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return false;
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return true;
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}
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/*
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* Enable the UEFI Runtime Services if all prerequisites are in place, i.e.,
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* non-early mapping of the UEFI system table and virtual mappings for all
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* EFI_MEMORY_RUNTIME regions.
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*/
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static int __init riscv_enable_runtime_services(void)
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{
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u64 mapsize;
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if (!efi_enabled(EFI_BOOT)) {
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pr_info("EFI services will not be available.\n");
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return 0;
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}
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efi_memmap_unmap();
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mapsize = efi.memmap.desc_size * efi.memmap.nr_map;
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if (efi_memmap_init_late(efi.memmap.phys_map, mapsize)) {
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pr_err("Failed to remap EFI memory map\n");
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return 0;
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}
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if (efi_soft_reserve_enabled()) {
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efi_memory_desc_t *md;
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for_each_efi_memory_desc(md) {
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u64 md_size = md->num_pages << EFI_PAGE_SHIFT;
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struct resource *res;
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if (!(md->attribute & EFI_MEMORY_SP))
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continue;
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res = kzalloc(sizeof(*res), GFP_KERNEL);
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if (WARN_ON(!res))
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break;
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res->start = md->phys_addr;
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res->end = md->phys_addr + md_size - 1;
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res->name = "Soft Reserved";
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res->flags = IORESOURCE_MEM;
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res->desc = IORES_DESC_SOFT_RESERVED;
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insert_resource(&iomem_resource, res);
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}
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}
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if (efi_runtime_disabled()) {
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pr_info("EFI runtime services will be disabled.\n");
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return 0;
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}
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if (efi_enabled(EFI_RUNTIME_SERVICES)) {
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pr_info("EFI runtime services access via paravirt.\n");
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return 0;
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}
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pr_info("Remapping and enabling EFI services.\n");
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if (!efi_virtmap_init()) {
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pr_err("UEFI virtual mapping missing or invalid -- runtime services will not be available\n");
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return -ENOMEM;
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}
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/* Set up runtime services function pointers */
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efi_native_runtime_setup();
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set_bit(EFI_RUNTIME_SERVICES, &efi.flags);
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return 0;
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}
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early_initcall(riscv_enable_runtime_services);
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void efi_virtmap_load(void)
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{
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preempt_disable();
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switch_mm(current->active_mm, &efi_mm, NULL);
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}
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void efi_virtmap_unload(void)
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{
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switch_mm(&efi_mm, current->active_mm, NULL);
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preempt_enable();
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}
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