efi_32.c
// SPDX-License-Identifier: GPL-2.0
/*
* Extensible Firmware Interface
*
* Based on Extensible Firmware Interface Specification version 1.0
*
* Copyright (C) 1999 VA Linux Systems
* Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
* Copyright (C) 1999-2002 Hewlett-Packard Co.
* David Mosberger-Tang <davidm@hpl.hp.com>
* Stephane Eranian <eranian@hpl.hp.com>
*
* All EFI Runtime Services are not implemented yet as EFI only
* supports physical mode addressing on SoftSDV. This is to be fixed
* in a future version. --drummond 1999-07-20
*
* Implemented EFI runtime services and virtual mode calls. --davidm
*
* Goutham Rao: <goutham.rao@intel.com>
* Skip non-WB memory and ignore empty memory ranges.
*/
#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/ioport.h>
#include <linux/efi.h>
#include <linux/pgtable.h>
#include <asm/io.h>
#include <asm/desc.h>
#include <asm/page.h>
#include <asm/set_memory.h>
#include <asm/tlbflush.h>
#include <asm/efi.h>
void __init efi_map_region(efi_memory_desc_t *md)
{
u64 start_pfn, end_pfn, end;
unsigned long size;
void *va;
start_pfn = PFN_DOWN(md->phys_addr);
size = md->num_pages << PAGE_SHIFT;
end = md->phys_addr + size;
end_pfn = PFN_UP(end);
if (pfn_range_is_mapped(start_pfn, end_pfn)) {
va = __va(md->phys_addr);
if (!(md->attribute & EFI_MEMORY_WB))
set_memory_uc((unsigned long)va, md->num_pages);
} else {
va = ioremap_cache(md->phys_addr, size);
}
md->virt_addr = (unsigned long)va;
if (!va)
pr_err("ioremap of 0x%llX failed!\n", md->phys_addr);
}
/*
* To make EFI call EFI runtime service in physical addressing mode we need
* prolog/epilog before/after the invocation to claim the EFI runtime service
* handler exclusively and to duplicate a memory mapping in low memory space,
* say 0 - 3G.
*/
int __init efi_alloc_page_tables(void)
{
return 0;
}
void efi_sync_low_kernel_mappings(void) {}
void __init efi_dump_pagetable(void)
{
#ifdef CONFIG_EFI_PGT_DUMP
ptdump_walk_pgd_level(NULL, &init_mm);
#endif
}
int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
{
return 0;
}
void __init efi_map_region_fixed(efi_memory_desc_t *md) {}
void __init parse_efi_setup(u64 phys_addr, u32 data_len) {}
efi_status_t efi_call_svam(efi_runtime_services_t * const *,
u32, u32, u32, void *, u32);
efi_status_t __init efi_set_virtual_address_map(unsigned long memory_map_size,
unsigned long descriptor_size,
u32 descriptor_version,
efi_memory_desc_t *virtual_map,
unsigned long systab_phys)
{
const efi_system_table_t *systab = (efi_system_table_t *)systab_phys;
struct desc_ptr gdt_descr;
efi_status_t status;
unsigned long flags;
pgd_t *save_pgd;
/* Current pgd is swapper_pg_dir, we'll restore it later: */
save_pgd = swapper_pg_dir;
load_cr3(initial_page_table);
__flush_tlb_all();
gdt_descr.address = get_cpu_gdt_paddr(0);
gdt_descr.size = GDT_SIZE - 1;
load_gdt(&gdt_descr);
/* Disable interrupts around EFI calls: */
local_irq_save(flags);
status = efi_call_svam(&systab->runtime,
memory_map_size, descriptor_size,
descriptor_version, virtual_map,
__pa(&efi.runtime));
local_irq_restore(flags);
load_fixmap_gdt(0);
load_cr3(save_pgd);
__flush_tlb_all();
return status;
}
void __init efi_runtime_update_mappings(void)
{
if (__supported_pte_mask & _PAGE_NX) {
efi_memory_desc_t *md;
/* Make EFI runtime service code area executable */
for_each_efi_memory_desc(md) {
if (md->type != EFI_RUNTIME_SERVICES_CODE)
continue;
set_memory_x(md->virt_addr, md->num_pages);
}
}
}