LoongArch: Add boot and setup routines

Add basic boot, setup and reset routines for LoongArch. Now, LoongArch
machines use UEFI-based firmware. The firmware passes configuration
information to the kernel via ACPI and DMI/SMBIOS.

Currently an existing interface between the kernel and the bootloader
is implemented. Kernel gets 2 values from the bootloader, passed in
registers a0 and a1; a0 is an "EFI boot flag" distinguishing UEFI and
non-UEFI firmware, while a1 is a pointer to an FDT with systable,
memmap, cmdline and initrd information.

The standard UEFI boot protocol (EFISTUB) will be added later.

Cc: linux-efi@vger.kernel.org
Cc: Ard Biesheuvel <ardb@kernel.org>
Reviewed-by: WANG Xuerui <git@xen0n.name>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Co-developed-by: Yun Liu <liuyun@loongson.cn>
Signed-off-by: Yun Liu <liuyun@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

1 files changed, 341 insertions, 0 deletions

diff --git a/arch/loongarch/kernel/setup.c b/arch/loongarch/kernel/setup.c
new file mode 100644
index 000000000000..29f3b82cd0a5
--- /dev/null
+++ b/arch/loongarch/kernel/setup.c
@@ -0,0 +1,341 @@
+// 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/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)
+
+#ifdef CONFIG_VT
+struct screen_info screen_info;
+#endif
+
+unsigned long fw_arg0, fw_arg1;
+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)
+{
+	int bios_extern;
+	char *dmi_data = (char *)dm;
+
+	bios_extern = *(dmi_data + SMBIOS_BIOSEXTERN_OFFSET);
+	b_info.bios_size = *(dmi_data + SMBIOS_BIOSSIZE_OFFSET);
+
+	if (bios_extern & LOONGSON_EFI_ENABLE)
+		set_bit(EFI_BOOT, &efi.flags);
+	else
+		clear_bit(EFI_BOOT, &efi.flags);
+}
+
+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;
+	}
+
+	memblock_add(start, size);
+
+	return 0;
+}
+early_param("mem", early_parse_mem);
+
+void __init platform_init(void)
+{
+	efi_init();
+#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
+
+	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);
+
+	swiotlb_init(true, SWIOTLB_VERBOSE);
+
+	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);
+
+void __init setup_arch(char **cmdline_p)
+{
+	cpu_probe();
+	*cmdline_p = boot_command_line;
+
+	init_environ();
+	memblock_init();
+	parse_early_param();
+
+	platform_init();
+	pagetable_init();
+	arch_mem_init(cmdline_p);
+
+	resource_init();
+
+	paging_init();
+}