cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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efi_32.c (3639B)

      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * Extensible Firmware Interface
      4 *
      5 * Based on Extensible Firmware Interface Specification version 1.0
      6 *
      7 * Copyright (C) 1999 VA Linux Systems
      8 * Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
      9 * Copyright (C) 1999-2002 Hewlett-Packard Co.
     10 *	David Mosberger-Tang <davidm@hpl.hp.com>
     11 *	Stephane Eranian <eranian@hpl.hp.com>
     12 *
     13 * All EFI Runtime Services are not implemented yet as EFI only
     14 * supports physical mode addressing on SoftSDV. This is to be fixed
     15 * in a future version.  --drummond 1999-07-20
     16 *
     17 * Implemented EFI runtime services and virtual mode calls.  --davidm
     18 *
     19 * Goutham Rao: <goutham.rao@intel.com>
     20 *	Skip non-WB memory and ignore empty memory ranges.
     21 */
     22
     23#include <linux/kernel.h>
     24#include <linux/types.h>
     25#include <linux/ioport.h>
     26#include <linux/efi.h>
     27#include <linux/pgtable.h>
     28
     29#include <asm/io.h>
     30#include <asm/desc.h>
     31#include <asm/page.h>
     32#include <asm/set_memory.h>
     33#include <asm/tlbflush.h>
     34#include <asm/efi.h>
     35
     36void __init efi_map_region(efi_memory_desc_t *md)
     37{
     38	u64 start_pfn, end_pfn, end;
     39	unsigned long size;
     40	void *va;
     41
     42	start_pfn	= PFN_DOWN(md->phys_addr);
     43	size		= md->num_pages << PAGE_SHIFT;
     44	end		= md->phys_addr + size;
     45	end_pfn 	= PFN_UP(end);
     46
     47	if (pfn_range_is_mapped(start_pfn, end_pfn)) {
     48		va = __va(md->phys_addr);
     49
     50		if (!(md->attribute & EFI_MEMORY_WB))
     51			set_memory_uc((unsigned long)va, md->num_pages);
     52	} else {
     53		va = ioremap_cache(md->phys_addr, size);
     54	}
     55
     56	md->virt_addr = (unsigned long)va;
     57	if (!va)
     58		pr_err("ioremap of 0x%llX failed!\n", md->phys_addr);
     59}
     60
     61/*
     62 * To make EFI call EFI runtime service in physical addressing mode we need
     63 * prolog/epilog before/after the invocation to claim the EFI runtime service
     64 * handler exclusively and to duplicate a memory mapping in low memory space,
     65 * say 0 - 3G.
     66 */
     67
     68int __init efi_alloc_page_tables(void)
     69{
     70	return 0;
     71}
     72
     73void efi_sync_low_kernel_mappings(void) {}
     74
     75void __init efi_dump_pagetable(void)
     76{
     77#ifdef CONFIG_EFI_PGT_DUMP
     78	ptdump_walk_pgd_level(NULL, &init_mm);
     79#endif
     80}
     81
     82int __init efi_setup_page_tables(unsigned long pa_memmap, unsigned num_pages)
     83{
     84	return 0;
     85}
     86
     87void __init efi_map_region_fixed(efi_memory_desc_t *md) {}
     88void __init parse_efi_setup(u64 phys_addr, u32 data_len) {}
     89
     90efi_status_t efi_call_svam(efi_runtime_services_t * const *,
     91			   u32, u32, u32, void *, u32);
     92
     93efi_status_t __init efi_set_virtual_address_map(unsigned long memory_map_size,
     94						unsigned long descriptor_size,
     95						u32 descriptor_version,
     96						efi_memory_desc_t *virtual_map,
     97						unsigned long systab_phys)
     98{
     99	const efi_system_table_t *systab = (efi_system_table_t *)systab_phys;
    100	struct desc_ptr gdt_descr;
    101	efi_status_t status;
    102	unsigned long flags;
    103	pgd_t *save_pgd;
    104
    105	/* Current pgd is swapper_pg_dir, we'll restore it later: */
    106	save_pgd = swapper_pg_dir;
    107	load_cr3(initial_page_table);
    108	__flush_tlb_all();
    109
    110	gdt_descr.address = get_cpu_gdt_paddr(0);
    111	gdt_descr.size = GDT_SIZE - 1;
    112	load_gdt(&gdt_descr);
    113
    114	/* Disable interrupts around EFI calls: */
    115	local_irq_save(flags);
    116	status = efi_call_svam(&systab->runtime,
    117			       memory_map_size, descriptor_size,
    118			       descriptor_version, virtual_map,
    119			       __pa(&efi.runtime));
    120	local_irq_restore(flags);
    121
    122	load_fixmap_gdt(0);
    123	load_cr3(save_pgd);
    124	__flush_tlb_all();
    125
    126	return status;
    127}
    128
    129void __init efi_runtime_update_mappings(void)
    130{
    131	if (__supported_pte_mask & _PAGE_NX) {
    132		efi_memory_desc_t *md;
    133
    134		/* Make EFI runtime service code area executable */
    135		for_each_efi_memory_desc(md) {
    136			if (md->type != EFI_RUNTIME_SERVICES_CODE)
    137				continue;
    138
    139			set_memory_x(md->virt_addr, md->num_pages);
    140		}
    141	}
    142}