/* * This file is subject to the terms and conditions of the GNU General Public * License. See the file "COPYING" in the main directory of this archive * for more details. * * 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/ioport.h> #include <linux/export.h> #include <linux/screen_info.h> #include <linux/memblock.h> #include <linux/bootmem.h> #include <linux/initrd.h> #include <linux/root_dev.h> #include <linux/highmem.h> #include <linux/console.h> #include <linux/pfn.h> #include <linux/debugfs.h> #include <linux/kexec.h> #include <linux/sizes.h> #include <linux/device.h> #include <linux/dma-contiguous.h> #include <linux/decompress/generic.h> #include <asm/addrspace.h> #include <asm/bootinfo.h> #include <asm/bugs.h> #include <asm/cache.h> #include <asm/cdmm.h> #include <asm/cpu.h> #include <asm/debug.h> #include <asm/sections.h> #include <asm/setup.h> #include <asm/smp-ops.h> #include <asm/prom.h> #ifdef CONFIG_MIPS_ELF_APPENDED_DTB const char __section(.appended_dtb) __appended_dtb[0x100000]; #endif /* CONFIG_MIPS_ELF_APPENDED_DTB */ struct cpuinfo_mips cpu_data[NR_CPUS] __read_mostly; EXPORT_SYMBOL(cpu_data); #ifdef CONFIG_VT struct screen_info screen_info; #endif /* * Setup information * * These are initialized so they are in the .data section */ unsigned long mips_machtype __read_mostly = MACH_UNKNOWN; EXPORT_SYMBOL(mips_machtype); struct boot_mem_map boot_mem_map; static char __initdata command_line[COMMAND_LINE_SIZE]; char __initdata arcs_cmdline[COMMAND_LINE_SIZE]; #ifdef CONFIG_CMDLINE_BOOL static char __initdata builtin_cmdline[COMMAND_LINE_SIZE] = CONFIG_CMDLINE; #endif /* * mips_io_port_base is the begin of the address space to which x86 style * I/O ports are mapped. */ const unsigned long mips_io_port_base = -1; EXPORT_SYMBOL(mips_io_port_base); static struct resource code_resource = { .name = "Kernel code", }; static struct resource data_resource = { .name = "Kernel data", }; static void *detect_magic __initdata = detect_memory_region; void __init add_memory_region(phys_addr_t start, phys_addr_t size, long type) { int x = boot_mem_map.nr_map; int i; /* * If the region reaches the top of the physical address space, adjust * the size slightly so that (start + size) doesn't overflow */ if (start + size - 1 == (phys_addr_t)ULLONG_MAX) --size; /* Sanity check */ if (start + size < start) { pr_warn("Trying to add an invalid memory region, skipped\n"); return; } /* * Try to merge with existing entry, if any. */ for (i = 0; i < boot_mem_map.nr_map; i++) { struct boot_mem_map_entry *entry = boot_mem_map.map + i; unsigned long top; if (entry->type != type) continue; if (start + size < entry->addr) continue; /* no overlap */ if (entry->addr + entry->size < start) continue; /* no overlap */ top = max(entry->addr + entry->size, start + size); entry->addr = min(entry->addr, start); entry->size = top - entry->addr; return; } if (boot_mem_map.nr_map == BOOT_MEM_MAP_MAX) { pr_err("Ooops! Too many entries in the memory map!\n"); return; } boot_mem_map.map[x].addr = start; boot_mem_map.map[x].size = size; boot_mem_map.map[x].type = type; boot_mem_map.nr_map++; } void __init detect_memory_region(phys_addr_t start, phys_addr_t sz_min, phys_addr_t sz_max) { void *dm = &detect_magic; phys_addr_t size; for (size = sz_min; size < sz_max; size <<= 1) { if (!memcmp(dm, dm + size, sizeof(detect_magic))) break; } pr_debug("Memory: %lluMB of RAM detected at 0x%llx (min: %lluMB, max: %lluMB)\n", ((unsigned long long) size) / SZ_1M, (unsigned long long) start, ((unsigned long long) sz_min) / SZ_1M, ((unsigned long long) sz_max) / SZ_1M); add_memory_region(start, size, BOOT_MEM_RAM); } static void __init print_memory_map(void) { int i; const int field = 2 * sizeof(unsigned long); for (i = 0; i < boot_mem_map.nr_map; i++) { printk(KERN_INFO " memory: %0*Lx @ %0*Lx ", field, (unsigned long long) boot_mem_map.map[i].size, field, (unsigned long long) boot_mem_map.map[i].addr); switch (boot_mem_map.map[i].type) { case BOOT_MEM_RAM: printk(KERN_CONT "(usable)\n"); break; case BOOT_MEM_INIT_RAM: printk(KERN_CONT "(usable after init)\n"); break; case BOOT_MEM_ROM_DATA: printk(KERN_CONT "(ROM data)\n"); break; case BOOT_MEM_RESERVED: printk(KERN_CONT "(reserved)\n"); break; default: printk(KERN_CONT "type %lu\n", boot_mem_map.map[i].type); break; } } } /* * Manage initrd */ #ifdef CONFIG_BLK_DEV_INITRD static int __init rd_start_early(char *p) { unsigned long start = memparse(p, &p); #ifdef CONFIG_64BIT /* Guess if the sign extension was forgotten by bootloader */ if (start < XKPHYS) start = (int)start; #endif initrd_start = start; initrd_end += start; return 0; } early_param("rd_start", rd_start_early); static int __init rd_size_early(char *p) { initrd_end += memparse(p, &p); return 0; } early_param("rd_size", rd_size_early); /* it returns the next free pfn after initrd */ static unsigned long __init init_initrd(void) { unsigned long end; /* * Board specific code or command line parser should have * already set up initrd_start and initrd_end. In these cases * perfom sanity checks and use them if all looks good. */ if (!initrd_start || initrd_end <= initrd_start) goto disable; if (initrd_start & ~PAGE_MASK) { pr_err("initrd start must be page aligned\n"); goto disable; } if (initrd_start < PAGE_OFFSET) { pr_err("initrd start < PAGE_OFFSET\n"); goto disable; } /* * Sanitize initrd addresses. For example firmware * can't guess if they need to pass them through * 64-bits values if the kernel has been built in pure * 32-bit. We need also to switch from KSEG0 to XKPHYS * addresses now, so the code can now safely use __pa(). */ end = __pa(initrd_end); initrd_end = (unsigned long)__va(end); initrd_start = (unsigned long)__va(__pa(initrd_start)); ROOT_DEV = Root_RAM0; return PFN_UP(end); disable: initrd_start = 0; initrd_end = 0; return 0; } /* In some conditions (e.g. big endian bootloader with a little endian kernel), the initrd might appear byte swapped. Try to detect this and byte swap it if needed. */ static void __init maybe_bswap_initrd(void) { #if defined(CONFIG_CPU_CAVIUM_OCTEON) u64 buf; /* Check for CPIO signature */ if (!memcmp((void *)initrd_start, "070701", 6)) return; /* Check for compressed initrd */ if (decompress_method((unsigned char *)initrd_start, 8, NULL)) return; /* Try again with a byte swapped header */ buf = swab64p((u64 *)initrd_start); if (!memcmp(&buf, "070701", 6) || decompress_method((unsigned char *)(&buf), 8, NULL)) { unsigned long i; pr_info("Byteswapped initrd detected\n"); for (i = initrd_start; i < ALIGN(initrd_end, 8); i += 8) swab64s((u64 *)i); } #endif } static void __init finalize_initrd(void) { unsigned long size = initrd_end - initrd_start; if (size == 0) { printk(KERN_INFO "Initrd not found or empty"); goto disable; } if (__pa(initrd_end) > PFN_PHYS(max_low_pfn)) { printk(KERN_ERR "Initrd extends beyond end of memory"); goto disable; } maybe_bswap_initrd(); reserve_bootmem(__pa(initrd_start), size, BOOTMEM_DEFAULT); initrd_below_start_ok = 1; pr_info("Initial ramdisk at: 0x%lx (%lu bytes)\n", initrd_start, size); return; disable: printk(KERN_CONT " - disabling initrd\n"); initrd_start = 0; initrd_end = 0; } #else /* !CONFIG_BLK_DEV_INITRD */ static unsigned long __init init_initrd(void) { return 0; } #define finalize_initrd() do {} while (0) #endif /* * Initialize the bootmem allocator. It also setup initrd related data * if needed. */ #if defined(CONFIG_SGI_IP27) || (defined(CONFIG_CPU_LOONGSON3) && defined(CONFIG_NUMA)) static void __init bootmem_init(void) { init_initrd(); finalize_initrd(); } #else /* !CONFIG_SGI_IP27 */ static void __init bootmem_init(void) { unsigned long reserved_end; unsigned long mapstart = ~0UL; unsigned long bootmap_size; int i; /* * Sanity check any INITRD first. We don't take it into account * for bootmem setup initially, rely on the end-of-kernel-code * as our memory range starting point. Once bootmem is inited we * will reserve the area used for the initrd. */ init_initrd(); reserved_end = (unsigned long) PFN_UP(__pa_symbol(&_end)); /* * max_low_pfn is not a number of pages. The number of pages * of the system is given by 'max_low_pfn - min_low_pfn'. */ min_low_pfn = ~0UL; max_low_pfn = 0; /* * Find the highest page frame number we have available. */ for (i = 0; i < boot_mem_map.nr_map; i++) { unsigned long start, end; if (boot_mem_map.map[i].type != BOOT_MEM_RAM) continue; start = PFN_UP(boot_mem_map.map[i].addr); end = PFN_DOWN(boot_mem_map.map[i].addr + boot_mem_map.map[i].size); #ifndef CONFIG_HIGHMEM /* * Skip highmem here so we get an accurate max_low_pfn if low * memory stops short of high memory. * If the region overlaps HIGHMEM_START, end is clipped so * max_pfn excludes the highmem portion. */ if (start >= PFN_DOWN(HIGHMEM_START)) continue; if (end > PFN_DOWN(HIGHMEM_START)) end = PFN_DOWN(HIGHMEM_START); #endif if (end > max_low_pfn) max_low_pfn = end; if (start < min_low_pfn) min_low_pfn = start; if (end <= reserved_end) continue; #ifdef CONFIG_BLK_DEV_INITRD /* Skip zones before initrd and initrd itself */ if (initrd_end && end <= (unsigned long)PFN_UP(__pa(initrd_end))) continue; #endif if (start >= mapstart) continue; mapstart = max(reserved_end, start); } if (min_low_pfn >= max_low_pfn) panic("Incorrect memory mapping !!!"); if (min_low_pfn > ARCH_PFN_OFFSET) { pr_info("Wasting %lu bytes for tracking %lu unused pages\n", (min_low_pfn - ARCH_PFN_OFFSET) * sizeof(struct page), min_low_pfn - ARCH_PFN_OFFSET); } else if (min_low_pfn < ARCH_PFN_OFFSET) { pr_info("%lu free pages won't be used\n", ARCH_PFN_OFFSET - min_low_pfn); } min_low_pfn = ARCH_PFN_OFFSET; /* * Determine low and high memory ranges */ max_pfn = max_low_pfn; if (max_low_pfn > PFN_DOWN(HIGHMEM_START)) { #ifdef CONFIG_HIGHMEM highstart_pfn = PFN_DOWN(HIGHMEM_START); highend_pfn = max_low_pfn; #endif max_low_pfn = PFN_DOWN(HIGHMEM_START); } #ifdef CONFIG_BLK_DEV_INITRD /* * mapstart should be after initrd_end */ if (initrd_end) mapstart = max(mapstart, (unsigned long)PFN_UP(__pa(initrd_end))); #endif /* * Initialize the boot-time allocator with low memory only. */ bootmap_size = init_bootmem_node(NODE_DATA(0), mapstart, min_low_pfn, max_low_pfn); for (i = 0; i < boot_mem_map.nr_map; i++) { unsigned long start, end; start = PFN_UP(boot_mem_map.map[i].addr); end = PFN_DOWN(boot_mem_map.map[i].addr + boot_mem_map.map[i].size); if (start <= min_low_pfn) start = min_low_pfn; if (start >= end) continue; #ifndef CONFIG_HIGHMEM if (end > max_low_pfn) end = max_low_pfn; /* * ... finally, is the area going away? */ if (end <= start) continue; #endif memblock_add_node(PFN_PHYS(start), PFN_PHYS(end - start), 0); } /* * Register fully available low RAM pages with the bootmem allocator. */ for (i = 0; i < boot_mem_map.nr_map; i++) { unsigned long start, end, size; start = PFN_UP(boot_mem_map.map[i].addr); end = PFN_DOWN(boot_mem_map.map[i].addr + boot_mem_map.map[i].size); /* * Reserve usable memory. */ switch (boot_mem_map.map[i].type) { case BOOT_MEM_RAM: break; case BOOT_MEM_INIT_RAM: memory_present(0, start, end); continue; default: /* Not usable memory */ continue; } /* * We are rounding up the start address of usable memory * and at the end of the usable range downwards. */ if (start >= max_low_pfn) continue; if (start < reserved_end) start = reserved_end; if (end > max_low_pfn) end = max_low_pfn; /* * ... finally, is the area going away? */ if (end <= start) continue; size = end - start; /* Register lowmem ranges */ free_bootmem(PFN_PHYS(start), size << PAGE_SHIFT); memory_present(0, start, end); } /* * Reserve the bootmap memory. */ reserve_bootmem(PFN_PHYS(mapstart), bootmap_size, BOOTMEM_DEFAULT); #ifdef CONFIG_RELOCATABLE /* * The kernel reserves all memory below its _end symbol as bootmem, * but the kernel may now be at a much higher address. The memory * between the original and new locations may be returned to the system. */ if (__pa_symbol(_text) > __pa_symbol(VMLINUX_LOAD_ADDRESS)) { unsigned long offset; extern void show_kernel_relocation(const char *level); offset = __pa_symbol(_text) - __pa_symbol(VMLINUX_LOAD_ADDRESS); free_bootmem(__pa_symbol(VMLINUX_LOAD_ADDRESS), offset); #if defined(CONFIG_DEBUG_KERNEL) && defined(CONFIG_DEBUG_INFO) /* * This information is necessary when debugging the kernel * But is a security vulnerability otherwise! */ show_kernel_relocation(KERN_INFO); #endif } #endif /* * Reserve initrd memory if needed. */ finalize_initrd(); } #endif /* CONFIG_SGI_IP27 */ /* * arch_mem_init - initialize memory management subsystem * * o plat_mem_setup() detects the memory configuration and will record detected * memory areas using add_memory_region. * * At this stage the memory configuration of the system is known to the * kernel but generic memory management system is still entirely uninitialized. * * o bootmem_init() * o sparse_init() * o paging_init() * o dma_contiguous_reserve() * * At this stage the bootmem allocator is ready to use. * * NOTE: historically plat_mem_setup did the entire platform initialization. * This was rather impractical because it meant plat_mem_setup had to * get away without any kind of memory allocator. To keep old code from * breaking plat_setup was just renamed to plat_mem_setup and a second platform * initialization hook for anything else was introduced. */ static int usermem __initdata; static int __init early_parse_mem(char *p) { phys_addr_t start, size; /* * If a user specifies memory size, we * blow away any automatically generated * size. */ if (usermem == 0) { boot_mem_map.nr_map = 0; usermem = 1; } start = 0; size = memparse(p, &p); if (*p == '@') start = memparse(p + 1, &p); add_memory_region(start, size, BOOT_MEM_RAM); return 0; } early_param("mem", early_parse_mem); #ifdef CONFIG_PROC_VMCORE unsigned long setup_elfcorehdr, setup_elfcorehdr_size; static int __init early_parse_elfcorehdr(char *p) { int i; setup_elfcorehdr = memparse(p, &p); for (i = 0; i < boot_mem_map.nr_map; i++) { unsigned long start = boot_mem_map.map[i].addr; unsigned long end = (boot_mem_map.map[i].addr + boot_mem_map.map[i].size); if (setup_elfcorehdr >= start && setup_elfcorehdr < end) { /* * Reserve from the elf core header to the end of * the memory segment, that should all be kdump * reserved memory. */ setup_elfcorehdr_size = end - setup_elfcorehdr; break; } } /* * If we don't find it in the memory map, then we shouldn't * have to worry about it, as the new kernel won't use it. */ return 0; } early_param("elfcorehdr", early_parse_elfcorehdr); #endif static void __init arch_mem_addpart(phys_addr_t mem, phys_addr_t end, int type) { phys_addr_t size; int i; size = end - mem; if (!size) return; /* Make sure it is in the boot_mem_map */ for (i = 0; i < boot_mem_map.nr_map; i++) { if (mem >= boot_mem_map.map[i].addr && mem < (boot_mem_map.map[i].addr + boot_mem_map.map[i].size)) return; } add_memory_region(mem, size, type); } #ifdef CONFIG_KEXEC static inline unsigned long long get_total_mem(void) { unsigned long long total; total = max_pfn - min_low_pfn; return total << PAGE_SHIFT; } static void __init mips_parse_crashkernel(void) { unsigned long long total_mem; unsigned long long crash_size, crash_base; int ret; total_mem = get_total_mem(); ret = parse_crashkernel(boot_command_line, total_mem, &crash_size, &crash_base); if (ret != 0 || crash_size <= 0) return; crashk_res.start = crash_base; crashk_res.end = crash_base + crash_size - 1; } static void __init request_crashkernel(struct resource *res) { int ret; ret = request_resource(res, &crashk_res); if (!ret) pr_info("Reserving %ldMB of memory at %ldMB for crashkernel\n", (unsigned long)((crashk_res.end - crashk_res.start + 1) >> 20), (unsigned long)(crashk_res.start >> 20)); } #else /* !defined(CONFIG_KEXEC) */ static void __init mips_parse_crashkernel(void) { } static void __init request_crashkernel(struct resource *res) { } #endif /* !defined(CONFIG_KEXEC) */ #define USE_PROM_CMDLINE IS_ENABLED(CONFIG_MIPS_CMDLINE_FROM_BOOTLOADER) #define USE_DTB_CMDLINE IS_ENABLED(CONFIG_MIPS_CMDLINE_FROM_DTB) #define EXTEND_WITH_PROM IS_ENABLED(CONFIG_MIPS_CMDLINE_DTB_EXTEND) #define BUILTIN_EXTEND_WITH_PROM \ IS_ENABLED(CONFIG_MIPS_CMDLINE_BUILTIN_EXTEND) static void __init arch_mem_init(char **cmdline_p) { struct memblock_region *reg; extern void plat_mem_setup(void); /* call board setup routine */ plat_mem_setup(); /* * Make sure all kernel memory is in the maps. The "UP" and * "DOWN" are opposite for initdata since if it crosses over * into another memory section you don't want that to be * freed when the initdata is freed. */ arch_mem_addpart(PFN_DOWN(__pa_symbol(&_text)) << PAGE_SHIFT, PFN_UP(__pa_symbol(&_edata)) << PAGE_SHIFT, BOOT_MEM_RAM); arch_mem_addpart(PFN_UP(__pa_symbol(&__init_begin)) << PAGE_SHIFT, PFN_DOWN(__pa_symbol(&__init_end)) << PAGE_SHIFT, BOOT_MEM_INIT_RAM); pr_info("Determined physical RAM map:\n"); print_memory_map(); #if defined(CONFIG_CMDLINE_BOOL) && defined(CONFIG_CMDLINE_OVERRIDE) strlcpy(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE); #else if ((USE_PROM_CMDLINE && arcs_cmdline[0]) || (USE_DTB_CMDLINE && !boot_command_line[0])) strlcpy(boot_command_line, arcs_cmdline, COMMAND_LINE_SIZE); if (EXTEND_WITH_PROM && arcs_cmdline[0]) { if (boot_command_line[0]) strlcat(boot_command_line, " ", COMMAND_LINE_SIZE); strlcat(boot_command_line, arcs_cmdline, COMMAND_LINE_SIZE); } #if defined(CONFIG_CMDLINE_BOOL) if (builtin_cmdline[0]) { if (boot_command_line[0]) strlcat(boot_command_line, " ", COMMAND_LINE_SIZE); strlcat(boot_command_line, builtin_cmdline, COMMAND_LINE_SIZE); } if (BUILTIN_EXTEND_WITH_PROM && arcs_cmdline[0]) { if (boot_command_line[0]) strlcat(boot_command_line, " ", COMMAND_LINE_SIZE); strlcat(boot_command_line, arcs_cmdline, COMMAND_LINE_SIZE); } #endif #endif strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE); *cmdline_p = command_line; parse_early_param(); if (usermem) { pr_info("User-defined physical RAM map:\n"); print_memory_map(); } bootmem_init(); #ifdef CONFIG_PROC_VMCORE if (setup_elfcorehdr && setup_elfcorehdr_size) { printk(KERN_INFO "kdump reserved memory at %lx-%lx\n", setup_elfcorehdr, setup_elfcorehdr_size); reserve_bootmem(setup_elfcorehdr, setup_elfcorehdr_size, BOOTMEM_DEFAULT); } #endif mips_parse_crashkernel(); #ifdef CONFIG_KEXEC if (crashk_res.start != crashk_res.end) reserve_bootmem(crashk_res.start, crashk_res.end - crashk_res.start + 1, BOOTMEM_DEFAULT); #endif device_tree_init(); sparse_init(); plat_swiotlb_setup(); dma_contiguous_reserve(PFN_PHYS(max_low_pfn)); /* Tell bootmem about cma reserved memblock section */ for_each_memblock(reserved, reg) if (reg->size != 0) reserve_bootmem(reg->base, reg->size, BOOTMEM_DEFAULT); reserve_bootmem_region(__pa_symbol(&__nosave_begin), __pa_symbol(&__nosave_end)); /* Reserve for hibernation */ } static void __init resource_init(void) { int i; if (UNCAC_BASE != IO_BASE) return; 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; for (i = 0; i < boot_mem_map.nr_map; i++) { struct resource *res; unsigned long start, end; start = boot_mem_map.map[i].addr; end = boot_mem_map.map[i].addr + boot_mem_map.map[i].size - 1; if (start >= HIGHMEM_START) continue; if (end >= HIGHMEM_START) end = HIGHMEM_START - 1; res = alloc_bootmem(sizeof(struct resource)); res->start = start; res->end = end; res->flags = IORESOURCE_MEM | IORESOURCE_BUSY; switch (boot_mem_map.map[i].type) { case BOOT_MEM_RAM: case BOOT_MEM_INIT_RAM: case BOOT_MEM_ROM_DATA: res->name = "System RAM"; res->flags |= IORESOURCE_SYSRAM; break; case BOOT_MEM_RESERVED: default: res->name = "reserved"; } 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_crashkernel(res); } } #ifdef CONFIG_SMP static void __init prefill_possible_map(void) { int i, possible = num_possible_cpus(); if (possible > nr_cpu_ids) possible = nr_cpu_ids; 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; } #else static inline void prefill_possible_map(void) {} #endif void __init setup_arch(char **cmdline_p) { cpu_probe(); mips_cm_probe(); prom_init(); setup_early_fdc_console(); #ifdef CONFIG_EARLY_PRINTK setup_early_printk(); #endif cpu_report(); check_bugs_early(); #if defined(CONFIG_VT) #if defined(CONFIG_VGA_CONSOLE) conswitchp = &vga_con; #elif defined(CONFIG_DUMMY_CONSOLE) conswitchp = &dummy_con; #endif #endif arch_mem_init(cmdline_p); resource_init(); plat_smp_setup(); prefill_possible_map(); cpu_cache_init(); paging_init(); } unsigned long kernelsp[NR_CPUS]; unsigned long fw_arg0, fw_arg1, fw_arg2, fw_arg3; #ifdef CONFIG_USE_OF unsigned long fw_passed_dtb; #endif #ifdef CONFIG_DEBUG_FS struct dentry *mips_debugfs_dir; static int __init debugfs_mips(void) { struct dentry *d; d = debugfs_create_dir("mips", NULL); if (!d) return -ENOMEM; mips_debugfs_dir = d; return 0; } arch_initcall(debugfs_mips); #endif