linux/arch/loongarch/kernel/setup.c
Ard Biesheuvel 40cd01a9c3 efi/loongarch: libstub: remove dependency on flattened DT
LoongArch does not use FDT or DT natively [yet], and the only reason it
currently uses it is so that it can reuse the existing EFI stub code.

Overloading the DT with data passed between the EFI stub and the core
kernel has been a source of problems: there is the overlap between
information provided by EFI which DT can also provide (initrd base/size,
command line, memory descriptions), requiring us to reason about which
is which and what to prioritize. It has also resulted in ABI leaks,
i.e., internal ABI being promoted to external ABI inadvertently because
the bootloader can set the EFI stub's DT properties as well (e.g.,
"kaslr-seed"). This has become especially problematic with boot
environments that want to pretend that EFI boot is being done (to access
ACPI and SMBIOS tables, for instance) but have no ability to execute the
EFI stub, and so the environment that the EFI stub creates is emulated
[poorly, in some cases].

Another downside of treating DT like this is that the DT binary that the
kernel receives is different from the one created by the firmware, which
is undesirable in the context of secure and measured boot.

Given that LoongArch support in Linux is brand new, we can avoid these
pitfalls, and treat the DT strictly as a hardware description, and use a
separate handover method between the EFI stub and the kernel. Now that
initrd loading and passing the EFI memory map have been refactored into
pure EFI routines that use EFI configuration tables, the only thing we
need to pass directly is the kernel command line (even if we could pass
this via a config table as well, it is used extremely early, so passing
it directly is preferred in this case.)

Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Huacai Chen <chenhuacai@loongson.cn>
2022-09-27 13:22:49 +02:00

365 lines
8.7 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2020-2022 Loongson Technology Corporation Limited
*
* Derived from MIPS:
* Copyright (C) 1995 Linus Torvalds
* Copyright (C) 1995 Waldorf Electronics
* Copyright (C) 1994, 95, 96, 97, 98, 99, 2000, 01, 02, 03 Ralf Baechle
* Copyright (C) 1996 Stoned Elipot
* Copyright (C) 1999 Silicon Graphics, Inc.
* Copyright (C) 2000, 2001, 2002, 2007 Maciej W. Rozycki
*/
#include <linux/init.h>
#include <linux/acpi.h>
#include <linux/dmi.h>
#include <linux/efi.h>
#include <linux/export.h>
#include <linux/screen_info.h>
#include <linux/memblock.h>
#include <linux/initrd.h>
#include <linux/ioport.h>
#include <linux/root_dev.h>
#include <linux/console.h>
#include <linux/pfn.h>
#include <linux/platform_device.h>
#include <linux/sizes.h>
#include <linux/device.h>
#include <linux/dma-map-ops.h>
#include <linux/swiotlb.h>
#include <asm/addrspace.h>
#include <asm/bootinfo.h>
#include <asm/cache.h>
#include <asm/cpu.h>
#include <asm/dma.h>
#include <asm/efi.h>
#include <asm/loongson.h>
#include <asm/numa.h>
#include <asm/pgalloc.h>
#include <asm/sections.h>
#include <asm/setup.h>
#include <asm/time.h>
#define SMBIOS_BIOSSIZE_OFFSET 0x09
#define SMBIOS_BIOSEXTERN_OFFSET 0x13
#define SMBIOS_FREQLOW_OFFSET 0x16
#define SMBIOS_FREQHIGH_OFFSET 0x17
#define SMBIOS_FREQLOW_MASK 0xFF
#define SMBIOS_CORE_PACKAGE_OFFSET 0x23
#define LOONGSON_EFI_ENABLE (1 << 3)
struct screen_info screen_info __section(".data");
unsigned long fw_arg0, fw_arg1, fw_arg2;
DEFINE_PER_CPU(unsigned long, kernelsp);
struct cpuinfo_loongarch cpu_data[NR_CPUS] __read_mostly;
EXPORT_SYMBOL(cpu_data);
struct loongson_board_info b_info;
static const char dmi_empty_string[] = " ";
/*
* Setup information
*
* These are initialized so they are in the .data section
*/
static int num_standard_resources;
static struct resource *standard_resources;
static struct resource code_resource = { .name = "Kernel code", };
static struct resource data_resource = { .name = "Kernel data", };
static struct resource bss_resource = { .name = "Kernel bss", };
const char *get_system_type(void)
{
return "generic-loongson-machine";
}
static const char *dmi_string_parse(const struct dmi_header *dm, u8 s)
{
const u8 *bp = ((u8 *) dm) + dm->length;
if (s) {
s--;
while (s > 0 && *bp) {
bp += strlen(bp) + 1;
s--;
}
if (*bp != 0) {
size_t len = strlen(bp)+1;
size_t cmp_len = len > 8 ? 8 : len;
if (!memcmp(bp, dmi_empty_string, cmp_len))
return dmi_empty_string;
return bp;
}
}
return "";
}
static void __init parse_cpu_table(const struct dmi_header *dm)
{
long freq_temp = 0;
char *dmi_data = (char *)dm;
freq_temp = ((*(dmi_data + SMBIOS_FREQHIGH_OFFSET) << 8) +
((*(dmi_data + SMBIOS_FREQLOW_OFFSET)) & SMBIOS_FREQLOW_MASK));
cpu_clock_freq = freq_temp * 1000000;
loongson_sysconf.cpuname = (void *)dmi_string_parse(dm, dmi_data[16]);
loongson_sysconf.cores_per_package = *(dmi_data + SMBIOS_CORE_PACKAGE_OFFSET);
pr_info("CpuClock = %llu\n", cpu_clock_freq);
}
static void __init parse_bios_table(const struct dmi_header *dm)
{
char *dmi_data = (char *)dm;
b_info.bios_size = (*(dmi_data + SMBIOS_BIOSSIZE_OFFSET) + 1) << 6;
}
static void __init find_tokens(const struct dmi_header *dm, void *dummy)
{
switch (dm->type) {
case 0x0: /* Extern BIOS */
parse_bios_table(dm);
break;
case 0x4: /* Calling interface */
parse_cpu_table(dm);
break;
}
}
static void __init smbios_parse(void)
{
b_info.bios_vendor = (void *)dmi_get_system_info(DMI_BIOS_VENDOR);
b_info.bios_version = (void *)dmi_get_system_info(DMI_BIOS_VERSION);
b_info.bios_release_date = (void *)dmi_get_system_info(DMI_BIOS_DATE);
b_info.board_vendor = (void *)dmi_get_system_info(DMI_BOARD_VENDOR);
b_info.board_name = (void *)dmi_get_system_info(DMI_BOARD_NAME);
dmi_walk(find_tokens, NULL);
}
static int usermem __initdata;
static int __init early_parse_mem(char *p)
{
phys_addr_t start, size;
if (!p) {
pr_err("mem parameter is empty, do nothing\n");
return -EINVAL;
}
/*
* If a user specifies memory size, we
* blow away any automatically generated
* size.
*/
if (usermem == 0) {
usermem = 1;
memblock_remove(memblock_start_of_DRAM(),
memblock_end_of_DRAM() - memblock_start_of_DRAM());
}
start = 0;
size = memparse(p, &p);
if (*p == '@')
start = memparse(p + 1, &p);
else {
pr_err("Invalid format!\n");
return -EINVAL;
}
if (!IS_ENABLED(CONFIG_NUMA))
memblock_add(start, size);
else
memblock_add_node(start, size, pa_to_nid(start), MEMBLOCK_NONE);
return 0;
}
early_param("mem", early_parse_mem);
void __init platform_init(void)
{
#ifdef CONFIG_ACPI_TABLE_UPGRADE
acpi_table_upgrade();
#endif
#ifdef CONFIG_ACPI
acpi_gbl_use_default_register_widths = false;
acpi_boot_table_init();
acpi_boot_init();
#endif
#ifdef CONFIG_NUMA
init_numa_memory();
#endif
dmi_setup();
smbios_parse();
pr_info("The BIOS Version: %s\n", b_info.bios_version);
efi_runtime_init();
}
static void __init check_kernel_sections_mem(void)
{
phys_addr_t start = __pa_symbol(&_text);
phys_addr_t size = __pa_symbol(&_end) - start;
if (!memblock_is_region_memory(start, size)) {
pr_info("Kernel sections are not in the memory maps\n");
memblock_add(start, size);
}
}
/*
* arch_mem_init - initialize memory management subsystem
*/
static void __init arch_mem_init(char **cmdline_p)
{
if (usermem)
pr_info("User-defined physical RAM map overwrite\n");
check_kernel_sections_mem();
/*
* In order to reduce the possibility of kernel panic when failed to
* get IO TLB memory under CONFIG_SWIOTLB, it is better to allocate
* low memory as small as possible before plat_swiotlb_setup(), so
* make sparse_init() using top-down allocation.
*/
memblock_set_bottom_up(false);
sparse_init();
memblock_set_bottom_up(true);
plat_swiotlb_setup();
dma_contiguous_reserve(PFN_PHYS(max_low_pfn));
memblock_dump_all();
early_memtest(PFN_PHYS(ARCH_PFN_OFFSET), PFN_PHYS(max_low_pfn));
}
static void __init resource_init(void)
{
long i = 0;
size_t res_size;
struct resource *res;
struct memblock_region *region;
code_resource.start = __pa_symbol(&_text);
code_resource.end = __pa_symbol(&_etext) - 1;
data_resource.start = __pa_symbol(&_etext);
data_resource.end = __pa_symbol(&_edata) - 1;
bss_resource.start = __pa_symbol(&__bss_start);
bss_resource.end = __pa_symbol(&__bss_stop) - 1;
num_standard_resources = memblock.memory.cnt;
res_size = num_standard_resources * sizeof(*standard_resources);
standard_resources = memblock_alloc(res_size, SMP_CACHE_BYTES);
for_each_mem_region(region) {
res = &standard_resources[i++];
if (!memblock_is_nomap(region)) {
res->name = "System RAM";
res->flags = IORESOURCE_SYSTEM_RAM | IORESOURCE_BUSY;
res->start = __pfn_to_phys(memblock_region_memory_base_pfn(region));
res->end = __pfn_to_phys(memblock_region_memory_end_pfn(region)) - 1;
} else {
res->name = "Reserved";
res->flags = IORESOURCE_MEM;
res->start = __pfn_to_phys(memblock_region_reserved_base_pfn(region));
res->end = __pfn_to_phys(memblock_region_reserved_end_pfn(region)) - 1;
}
request_resource(&iomem_resource, res);
/*
* We don't know which RAM region contains kernel data,
* so we try it repeatedly and let the resource manager
* test it.
*/
request_resource(res, &code_resource);
request_resource(res, &data_resource);
request_resource(res, &bss_resource);
}
}
static int __init reserve_memblock_reserved_regions(void)
{
u64 i, j;
for (i = 0; i < num_standard_resources; ++i) {
struct resource *mem = &standard_resources[i];
phys_addr_t r_start, r_end, mem_size = resource_size(mem);
if (!memblock_is_region_reserved(mem->start, mem_size))
continue;
for_each_reserved_mem_range(j, &r_start, &r_end) {
resource_size_t start, end;
start = max(PFN_PHYS(PFN_DOWN(r_start)), mem->start);
end = min(PFN_PHYS(PFN_UP(r_end)) - 1, mem->end);
if (start > mem->end || end < mem->start)
continue;
reserve_region_with_split(mem, start, end, "Reserved");
}
}
return 0;
}
arch_initcall(reserve_memblock_reserved_regions);
#ifdef CONFIG_SMP
static void __init prefill_possible_map(void)
{
int i, possible;
possible = num_processors + disabled_cpus;
if (possible > nr_cpu_ids)
possible = nr_cpu_ids;
pr_info("SMP: Allowing %d CPUs, %d hotplug CPUs\n",
possible, max((possible - num_processors), 0));
for (i = 0; i < possible; i++)
set_cpu_possible(i, true);
for (; i < NR_CPUS; i++)
set_cpu_possible(i, false);
nr_cpu_ids = possible;
}
#endif
void __init setup_arch(char **cmdline_p)
{
cpu_probe();
*cmdline_p = boot_command_line;
init_environ();
efi_init();
memblock_init();
parse_early_param();
platform_init();
pagetable_init();
arch_mem_init(cmdline_p);
resource_init();
#ifdef CONFIG_SMP
plat_smp_setup();
prefill_possible_map();
#endif
paging_init();
}