cregit-Linux how code gets into the kernel

Release 4.7 drivers/firmware/efi/arm-runtime.c

/*
 * Extensible Firmware Interface
 *
 * Based on Extensible Firmware Interface Specification version 2.4
 *
 * Copyright (C) 2013, 2014 Linaro Ltd.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 *
 */

#include <linux/efi.h>
#include <linux/io.h>
#include <linux/memblock.h>
#include <linux/mm_types.h>
#include <linux/preempt.h>
#include <linux/rbtree.h>
#include <linux/rwsem.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>

#include <asm/cacheflush.h>
#include <asm/efi.h>
#include <asm/mmu.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>

extern u64 efi_system_table;


static struct mm_struct efi_mm = {
	.mm_rb			= RB_ROOT,
	.mm_users		= ATOMIC_INIT(2),
	.mm_count		= ATOMIC_INIT(1),
	.mmap_sem		= __RWSEM_INITIALIZER(efi_mm.mmap_sem),
	.page_table_lock	= __SPIN_LOCK_UNLOCKED(efi_mm.page_table_lock),
	.mmlist			= LIST_HEAD_INIT(efi_mm.mmlist),
};


static bool __init efi_virtmap_init(void) { efi_memory_desc_t *md; bool systab_found; efi_mm.pgd = pgd_alloc(&efi_mm); init_new_context(NULL, &efi_mm); systab_found = false; for_each_efi_memory_desc(md) { phys_addr_t phys = md->phys_addr; int ret; if (!(md->attribute & EFI_MEMORY_RUNTIME)) continue; if (md->virt_addr == 0) return false; ret = efi_create_mapping(&efi_mm, md); if (!ret) { pr_info(" EFI remap %pa => %p\n", &phys, (void *)(unsigned long)md->virt_addr); } else { pr_warn(" EFI remap %pa: failed to create mapping (%d)\n", &phys, ret); return false; } /* * If this entry covers the address of the UEFI system table, * calculate and record its virtual address. */ if (efi_system_table >= phys && efi_system_table < phys + (md->num_pages * EFI_PAGE_SIZE)) { efi.systab = (void *)(unsigned long)(efi_system_table - phys + md->virt_addr); systab_found = true; } } if (!systab_found) { pr_err("No virtual mapping found for the UEFI System Table\n"); return false; } if (efi_memattr_apply_permissions(&efi_mm, efi_set_mapping_permissions)) return false; return true; }

Contributors

PersonTokensPropCommitsCommitProp
ard biesheuvelard biesheuvel208100.00%4100.00%
Total208100.00%4100.00%

/* * Enable the UEFI Runtime Services if all prerequisites are in place, i.e., * non-early mapping of the UEFI system table and virtual mappings for all * EFI_MEMORY_RUNTIME regions. */
static int __init arm_enable_runtime_services(void) { u64 mapsize; if (!efi_enabled(EFI_BOOT)) { pr_info("EFI services will not be available.\n"); return 0; } if (efi_runtime_disabled()) { pr_info("EFI runtime services will be disabled.\n"); return 0; } pr_info("Remapping and enabling EFI services.\n"); mapsize = efi.memmap.map_end - efi.memmap.map; efi.memmap.map = memremap(efi.memmap.phys_map, mapsize, MEMREMAP_WB); if (!efi.memmap.map) { pr_err("Failed to remap EFI memory map\n"); return -ENOMEM; } efi.memmap.map_end = efi.memmap.map + mapsize; if (!efi_virtmap_init()) { pr_err("UEFI virtual mapping missing or invalid -- runtime services will not be available\n"); return -ENOMEM; } /* Set up runtime services function pointers */ efi_native_runtime_setup(); set_bit(EFI_RUNTIME_SERVICES, &efi.flags); return 0; }

Contributors

PersonTokensPropCommitsCommitProp
ard biesheuvelard biesheuvel13790.73%480.00%
matt flemingmatt fleming149.27%120.00%
Total151100.00%5100.00%

early_initcall(arm_enable_runtime_services);
void efi_virtmap_load(void) { preempt_disable(); efi_set_pgd(&efi_mm); }

Contributors

PersonTokensPropCommitsCommitProp
ard biesheuvelard biesheuvel16100.00%1100.00%
Total16100.00%1100.00%


void efi_virtmap_unload(void) { efi_set_pgd(current->active_mm); preempt_enable(); }

Contributors

PersonTokensPropCommitsCommitProp
ard biesheuvelard biesheuvel17100.00%1100.00%
Total17100.00%1100.00%


Overall Contributors

PersonTokensPropCommitsCommitProp
ard biesheuvelard biesheuvel49297.23%583.33%
matt flemingmatt fleming142.77%116.67%
Total506100.00%6100.00%
Information contained on this website is for historical information purposes only and does not indicate or represent copyright ownership.
{% endraw %}