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/*
* This file is part of the coreboot project.
*
* Copyright (C) 2019 9elements Agency GmbH
* Copyright (C) 2019 Facebook Inc.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; version 2 of the License.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#if CONFIG(ARCH_X86)
#include <cpu/x86/pae.h>
#else
#define memset_pae(a, b, c, d, e) 0
#define MEMSET_PAE_PGTL_ALIGN 0
#define MEMSET_PAE_PGTL_SIZE 0
#define MEMSET_PAE_PGTL_SIZE 0
#define MEMSET_PAE_VMEM_ALIGN 0
#endif
#include <memrange.h>
#include <bootmem.h>
#include <bootstate.h>
#include <symbols.h>
#include <console/console.h>
#include <arch/memory_clear.h>
#include <string.h>
#include <security/memory/memory.h>
#include <cbmem.h>
#include <arch/acpi.h>
/* Helper to find free space for memset_pae. */
static uintptr_t get_free_memory_range(struct memranges *mem,
const resource_t align,
const resource_t size)
{
const struct range_entry *r;
/* Find a spot for virtual memory address */
memranges_each_entry(r, mem) {
if (range_entry_tag(r) != BM_MEM_RAM)
continue;
if (ALIGN_UP(range_entry_base(r) + size, align) + size >
range_entry_end(r))
continue;
return ALIGN_UP(range_entry_base(r) + size, align);
}
printk(BIOS_ERR, "%s: Couldn't find free memory range\n", __func__);
return 0;
}
/*
* Clears all memory regions marked as BM_MEM_RAM.
* Uses memset_pae if the memory region can't be accessed by memset and
* architecture is x86.
*
* @return 0 on success, 1 on error
*/
static void clear_memory(void *unused)
{
const struct range_entry *r;
struct memranges mem;
uintptr_t pgtbl, vmem_addr;
if (acpi_is_wakeup_s3())
return;
if (!security_clear_dram_request())
return;
/* FSP1.0 is marked as MMIO and won't appear here */
memranges_init(&mem, IORESOURCE_MEM | IORESOURCE_FIXED |
IORESOURCE_STORED | IORESOURCE_ASSIGNED |
IORESOURCE_CACHEABLE,
IORESOURCE_MEM | IORESOURCE_FIXED |
IORESOURCE_STORED | IORESOURCE_ASSIGNED |
IORESOURCE_CACHEABLE,
BM_MEM_RAM);
/* Add reserved entries */
void *baseptr = NULL;
size_t size = 0;
/* Only skip CBMEM, as RELOCATABLE_RAMSTAGE is a requirement, no need
* to separately protect stack or heap */
cbmem_get_region(&baseptr, &size);
memranges_insert(&mem, (uintptr_t)baseptr, size, BM_MEM_TABLE);
if (CONFIG(ARCH_X86)) {
/* Find space for PAE enabled memset */
pgtbl = get_free_memory_range(&mem, MEMSET_PAE_PGTL_ALIGN,
MEMSET_PAE_PGTL_SIZE);
/* Don't touch page tables while clearing */
memranges_insert(&mem, pgtbl, MEMSET_PAE_PGTL_SIZE,
BM_MEM_TABLE);
vmem_addr = get_free_memory_range(&mem, MEMSET_PAE_VMEM_ALIGN,
MEMSET_PAE_PGTL_SIZE);
printk(BIOS_SPEW, "%s: pgtbl at %p, virt memory at %p\n",
__func__, (void *)pgtbl, (void *)vmem_addr);
}
/* Now clear all useable DRAM */
memranges_each_entry(r, &mem) {
if (range_entry_tag(r) != BM_MEM_RAM)
continue;
printk(BIOS_DEBUG, "%s: Clearing DRAM %016llx-%016llx\n",
__func__, range_entry_base(r), range_entry_end(r));
/* Does regular memset work? */
if (sizeof(resource_t) == sizeof(void *) ||
!(range_entry_end(r) >> (sizeof(void *) * 8))) {
/* fastpath */
memset((void *)(uintptr_t)range_entry_base(r), 0,
range_entry_size(r));
}
/* Use PAE if available */
else if (CONFIG(ARCH_X86)) {
if (memset_pae(range_entry_base(r), 0,
range_entry_size(r), (void *)pgtbl,
(void *)vmem_addr))
printk(BIOS_ERR, "%s: Failed to memset "
"memory\n", __func__);
} else {
printk(BIOS_ERR, "%s: Failed to memset memory\n",
__func__);
}
}
if (CONFIG(ARCH_X86)) {
/* Clear previously skipped memory reserved for pagetables */
printk(BIOS_DEBUG, "%s: Clearing DRAM %016lx-%016lx\n",
__func__, pgtbl, pgtbl + MEMSET_PAE_PGTL_SIZE);
memset((void *)pgtbl, 0, MEMSET_PAE_PGTL_SIZE);
}
memranges_teardown(&mem);
}
/* After DEV_INIT as MTRRs needs to be configured on x86 */
BOOT_STATE_INIT_ENTRY(BS_DEV_INIT, BS_ON_EXIT, clear_memory, NULL);
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