Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 1 | /* |
| 2 | * machine_kexec.c - handle transition of Linux booting another kernel |
| 3 | * Copyright (C) 2002-2005 Eric Biederman <ebiederm@xmission.com> |
| 4 | * |
| 5 | * This source code is licensed under the GNU General Public License, |
| 6 | * Version 2. See the file COPYING for more details. |
| 7 | */ |
| 8 | |
| 9 | #include <linux/mm.h> |
| 10 | #include <linux/kexec.h> |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 11 | #include <linux/string.h> |
| 12 | #include <linux/reboot.h> |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 13 | #include <asm/pgtable.h> |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 14 | #include <asm/tlbflush.h> |
| 15 | #include <asm/mmu_context.h> |
| 16 | #include <asm/io.h> |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 17 | |
Magnus Damm | 4bfaaef | 2006-09-26 10:52:38 +0200 | [diff] [blame] | 18 | #define PAGE_ALIGNED __attribute__ ((__aligned__(PAGE_SIZE))) |
| 19 | static u64 kexec_pgd[512] PAGE_ALIGNED; |
| 20 | static u64 kexec_pud0[512] PAGE_ALIGNED; |
| 21 | static u64 kexec_pmd0[512] PAGE_ALIGNED; |
| 22 | static u64 kexec_pte0[512] PAGE_ALIGNED; |
| 23 | static u64 kexec_pud1[512] PAGE_ALIGNED; |
| 24 | static u64 kexec_pmd1[512] PAGE_ALIGNED; |
| 25 | static u64 kexec_pte1[512] PAGE_ALIGNED; |
| 26 | |
Eric W. Biederman | 8bf2755 | 2005-07-29 13:25:28 -0600 | [diff] [blame] | 27 | static void init_level2_page(pmd_t *level2p, unsigned long addr) |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 28 | { |
| 29 | unsigned long end_addr; |
Maneesh Soni | 72414d3 | 2005-06-25 14:58:28 -0700 | [diff] [blame] | 30 | |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 31 | addr &= PAGE_MASK; |
Eric W. Biederman | 8bf2755 | 2005-07-29 13:25:28 -0600 | [diff] [blame] | 32 | end_addr = addr + PUD_SIZE; |
Maneesh Soni | 72414d3 | 2005-06-25 14:58:28 -0700 | [diff] [blame] | 33 | while (addr < end_addr) { |
Eric W. Biederman | 8bf2755 | 2005-07-29 13:25:28 -0600 | [diff] [blame] | 34 | set_pmd(level2p++, __pmd(addr | __PAGE_KERNEL_LARGE_EXEC)); |
| 35 | addr += PMD_SIZE; |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 36 | } |
| 37 | } |
| 38 | |
Eric W. Biederman | 8bf2755 | 2005-07-29 13:25:28 -0600 | [diff] [blame] | 39 | static int init_level3_page(struct kimage *image, pud_t *level3p, |
Maneesh Soni | 72414d3 | 2005-06-25 14:58:28 -0700 | [diff] [blame] | 40 | unsigned long addr, unsigned long last_addr) |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 41 | { |
| 42 | unsigned long end_addr; |
| 43 | int result; |
Maneesh Soni | 72414d3 | 2005-06-25 14:58:28 -0700 | [diff] [blame] | 44 | |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 45 | result = 0; |
| 46 | addr &= PAGE_MASK; |
Eric W. Biederman | 8bf2755 | 2005-07-29 13:25:28 -0600 | [diff] [blame] | 47 | end_addr = addr + PGDIR_SIZE; |
Maneesh Soni | 72414d3 | 2005-06-25 14:58:28 -0700 | [diff] [blame] | 48 | while ((addr < last_addr) && (addr < end_addr)) { |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 49 | struct page *page; |
Eric W. Biederman | 8bf2755 | 2005-07-29 13:25:28 -0600 | [diff] [blame] | 50 | pmd_t *level2p; |
Maneesh Soni | 72414d3 | 2005-06-25 14:58:28 -0700 | [diff] [blame] | 51 | |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 52 | page = kimage_alloc_control_pages(image, 0); |
| 53 | if (!page) { |
| 54 | result = -ENOMEM; |
| 55 | goto out; |
| 56 | } |
Eric W. Biederman | 8bf2755 | 2005-07-29 13:25:28 -0600 | [diff] [blame] | 57 | level2p = (pmd_t *)page_address(page); |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 58 | init_level2_page(level2p, addr); |
Eric W. Biederman | 8bf2755 | 2005-07-29 13:25:28 -0600 | [diff] [blame] | 59 | set_pud(level3p++, __pud(__pa(level2p) | _KERNPG_TABLE)); |
| 60 | addr += PUD_SIZE; |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 61 | } |
| 62 | /* clear the unused entries */ |
Maneesh Soni | 72414d3 | 2005-06-25 14:58:28 -0700 | [diff] [blame] | 63 | while (addr < end_addr) { |
Eric W. Biederman | 8bf2755 | 2005-07-29 13:25:28 -0600 | [diff] [blame] | 64 | pud_clear(level3p++); |
| 65 | addr += PUD_SIZE; |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 66 | } |
| 67 | out: |
| 68 | return result; |
| 69 | } |
| 70 | |
| 71 | |
Eric W. Biederman | 8bf2755 | 2005-07-29 13:25:28 -0600 | [diff] [blame] | 72 | static int init_level4_page(struct kimage *image, pgd_t *level4p, |
Maneesh Soni | 72414d3 | 2005-06-25 14:58:28 -0700 | [diff] [blame] | 73 | unsigned long addr, unsigned long last_addr) |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 74 | { |
| 75 | unsigned long end_addr; |
| 76 | int result; |
Maneesh Soni | 72414d3 | 2005-06-25 14:58:28 -0700 | [diff] [blame] | 77 | |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 78 | result = 0; |
| 79 | addr &= PAGE_MASK; |
Eric W. Biederman | 8bf2755 | 2005-07-29 13:25:28 -0600 | [diff] [blame] | 80 | end_addr = addr + (PTRS_PER_PGD * PGDIR_SIZE); |
Maneesh Soni | 72414d3 | 2005-06-25 14:58:28 -0700 | [diff] [blame] | 81 | while ((addr < last_addr) && (addr < end_addr)) { |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 82 | struct page *page; |
Eric W. Biederman | 8bf2755 | 2005-07-29 13:25:28 -0600 | [diff] [blame] | 83 | pud_t *level3p; |
Maneesh Soni | 72414d3 | 2005-06-25 14:58:28 -0700 | [diff] [blame] | 84 | |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 85 | page = kimage_alloc_control_pages(image, 0); |
| 86 | if (!page) { |
| 87 | result = -ENOMEM; |
| 88 | goto out; |
| 89 | } |
Eric W. Biederman | 8bf2755 | 2005-07-29 13:25:28 -0600 | [diff] [blame] | 90 | level3p = (pud_t *)page_address(page); |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 91 | result = init_level3_page(image, level3p, addr, last_addr); |
| 92 | if (result) { |
| 93 | goto out; |
| 94 | } |
Eric W. Biederman | 8bf2755 | 2005-07-29 13:25:28 -0600 | [diff] [blame] | 95 | set_pgd(level4p++, __pgd(__pa(level3p) | _KERNPG_TABLE)); |
| 96 | addr += PGDIR_SIZE; |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 97 | } |
| 98 | /* clear the unused entries */ |
Maneesh Soni | 72414d3 | 2005-06-25 14:58:28 -0700 | [diff] [blame] | 99 | while (addr < end_addr) { |
Eric W. Biederman | 8bf2755 | 2005-07-29 13:25:28 -0600 | [diff] [blame] | 100 | pgd_clear(level4p++); |
| 101 | addr += PGDIR_SIZE; |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 102 | } |
Maneesh Soni | 72414d3 | 2005-06-25 14:58:28 -0700 | [diff] [blame] | 103 | out: |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 104 | return result; |
| 105 | } |
| 106 | |
| 107 | |
| 108 | static int init_pgtable(struct kimage *image, unsigned long start_pgtable) |
| 109 | { |
Eric W. Biederman | 8bf2755 | 2005-07-29 13:25:28 -0600 | [diff] [blame] | 110 | pgd_t *level4p; |
| 111 | level4p = (pgd_t *)__va(start_pgtable); |
Maneesh Soni | 72414d3 | 2005-06-25 14:58:28 -0700 | [diff] [blame] | 112 | return init_level4_page(image, level4p, 0, end_pfn << PAGE_SHIFT); |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 113 | } |
| 114 | |
| 115 | static void set_idt(void *newidt, u16 limit) |
| 116 | { |
Eric W. Biederman | 36c4fd2 | 2005-07-29 13:02:09 -0600 | [diff] [blame] | 117 | struct desc_ptr curidt; |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 118 | |
| 119 | /* x86-64 supports unaliged loads & stores */ |
Eric W. Biederman | 36c4fd2 | 2005-07-29 13:02:09 -0600 | [diff] [blame] | 120 | curidt.size = limit; |
| 121 | curidt.address = (unsigned long)newidt; |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 122 | |
| 123 | __asm__ __volatile__ ( |
Eric W. Biederman | 36c4fd2 | 2005-07-29 13:02:09 -0600 | [diff] [blame] | 124 | "lidtq %0\n" |
| 125 | : : "m" (curidt) |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 126 | ); |
| 127 | }; |
| 128 | |
| 129 | |
| 130 | static void set_gdt(void *newgdt, u16 limit) |
| 131 | { |
Eric W. Biederman | 36c4fd2 | 2005-07-29 13:02:09 -0600 | [diff] [blame] | 132 | struct desc_ptr curgdt; |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 133 | |
| 134 | /* x86-64 supports unaligned loads & stores */ |
Eric W. Biederman | 36c4fd2 | 2005-07-29 13:02:09 -0600 | [diff] [blame] | 135 | curgdt.size = limit; |
| 136 | curgdt.address = (unsigned long)newgdt; |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 137 | |
| 138 | __asm__ __volatile__ ( |
Eric W. Biederman | 36c4fd2 | 2005-07-29 13:02:09 -0600 | [diff] [blame] | 139 | "lgdtq %0\n" |
| 140 | : : "m" (curgdt) |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 141 | ); |
| 142 | }; |
| 143 | |
| 144 | static void load_segments(void) |
| 145 | { |
| 146 | __asm__ __volatile__ ( |
Eric W. Biederman | 36c4fd2 | 2005-07-29 13:02:09 -0600 | [diff] [blame] | 147 | "\tmovl %0,%%ds\n" |
| 148 | "\tmovl %0,%%es\n" |
| 149 | "\tmovl %0,%%ss\n" |
| 150 | "\tmovl %0,%%fs\n" |
| 151 | "\tmovl %0,%%gs\n" |
Michael Matz | 2ec5e3a | 2006-03-07 21:55:48 -0800 | [diff] [blame] | 152 | : : "a" (__KERNEL_DS) : "memory" |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 153 | ); |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 154 | } |
| 155 | |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 156 | int machine_kexec_prepare(struct kimage *image) |
| 157 | { |
Magnus Damm | 4bfaaef | 2006-09-26 10:52:38 +0200 | [diff] [blame] | 158 | unsigned long start_pgtable; |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 159 | int result; |
| 160 | |
| 161 | /* Calculate the offsets */ |
Maneesh Soni | 72414d3 | 2005-06-25 14:58:28 -0700 | [diff] [blame] | 162 | start_pgtable = page_to_pfn(image->control_code_page) << PAGE_SHIFT; |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 163 | |
| 164 | /* Setup the identity mapped 64bit page table */ |
| 165 | result = init_pgtable(image, start_pgtable); |
Maneesh Soni | 72414d3 | 2005-06-25 14:58:28 -0700 | [diff] [blame] | 166 | if (result) |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 167 | return result; |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 168 | |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 169 | return 0; |
| 170 | } |
| 171 | |
| 172 | void machine_kexec_cleanup(struct kimage *image) |
| 173 | { |
| 174 | return; |
| 175 | } |
| 176 | |
| 177 | /* |
| 178 | * Do not allocate memory (or fail in any way) in machine_kexec(). |
| 179 | * We are past the point of no return, committed to rebooting now. |
| 180 | */ |
| 181 | NORET_TYPE void machine_kexec(struct kimage *image) |
| 182 | { |
Magnus Damm | 4bfaaef | 2006-09-26 10:52:38 +0200 | [diff] [blame] | 183 | unsigned long page_list[PAGES_NR]; |
| 184 | void *control_page; |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 185 | |
| 186 | /* Interrupts aren't acceptable while we reboot */ |
| 187 | local_irq_disable(); |
| 188 | |
Magnus Damm | 4bfaaef | 2006-09-26 10:52:38 +0200 | [diff] [blame] | 189 | control_page = page_address(image->control_code_page) + PAGE_SIZE; |
| 190 | memcpy(control_page, relocate_kernel, PAGE_SIZE); |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 191 | |
Magnus Damm | 4bfaaef | 2006-09-26 10:52:38 +0200 | [diff] [blame] | 192 | page_list[PA_CONTROL_PAGE] = __pa(control_page); |
| 193 | page_list[VA_CONTROL_PAGE] = (unsigned long)relocate_kernel; |
| 194 | page_list[PA_PGD] = __pa(kexec_pgd); |
| 195 | page_list[VA_PGD] = (unsigned long)kexec_pgd; |
| 196 | page_list[PA_PUD_0] = __pa(kexec_pud0); |
| 197 | page_list[VA_PUD_0] = (unsigned long)kexec_pud0; |
| 198 | page_list[PA_PMD_0] = __pa(kexec_pmd0); |
| 199 | page_list[VA_PMD_0] = (unsigned long)kexec_pmd0; |
| 200 | page_list[PA_PTE_0] = __pa(kexec_pte0); |
| 201 | page_list[VA_PTE_0] = (unsigned long)kexec_pte0; |
| 202 | page_list[PA_PUD_1] = __pa(kexec_pud1); |
| 203 | page_list[VA_PUD_1] = (unsigned long)kexec_pud1; |
| 204 | page_list[PA_PMD_1] = __pa(kexec_pmd1); |
| 205 | page_list[VA_PMD_1] = (unsigned long)kexec_pmd1; |
| 206 | page_list[PA_PTE_1] = __pa(kexec_pte1); |
| 207 | page_list[VA_PTE_1] = (unsigned long)kexec_pte1; |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 208 | |
Magnus Damm | 4bfaaef | 2006-09-26 10:52:38 +0200 | [diff] [blame] | 209 | page_list[PA_TABLE_PAGE] = |
| 210 | (unsigned long)__pa(page_address(image->control_code_page)); |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 211 | |
Eric W. Biederman | 2a8a3d5 | 2006-07-30 03:03:20 -0700 | [diff] [blame] | 212 | /* The segment registers are funny things, they have both a |
| 213 | * visible and an invisible part. Whenever the visible part is |
| 214 | * set to a specific selector, the invisible part is loaded |
| 215 | * with from a table in memory. At no other time is the |
| 216 | * descriptor table in memory accessed. |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 217 | * |
| 218 | * I take advantage of this here by force loading the |
| 219 | * segments, before I zap the gdt with an invalid value. |
| 220 | */ |
| 221 | load_segments(); |
| 222 | /* The gdt & idt are now invalid. |
| 223 | * If you want to load them you must set up your own idt & gdt. |
| 224 | */ |
| 225 | set_gdt(phys_to_virt(0),0); |
| 226 | set_idt(phys_to_virt(0),0); |
Magnus Damm | 4bfaaef | 2006-09-26 10:52:38 +0200 | [diff] [blame] | 227 | |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 228 | /* now call it */ |
Magnus Damm | 4bfaaef | 2006-09-26 10:52:38 +0200 | [diff] [blame] | 229 | relocate_kernel((unsigned long)image->head, (unsigned long)page_list, |
| 230 | image->start); |
Eric W. Biederman | 5234f5e | 2005-06-25 14:58:02 -0700 | [diff] [blame] | 231 | } |
Andi Kleen | 2c8c0e6 | 2006-09-26 10:52:32 +0200 | [diff] [blame] | 232 | |
| 233 | /* crashkernel=size@addr specifies the location to reserve for |
| 234 | * a crash kernel. By reserving this memory we guarantee |
| 235 | * that linux never set's it up as a DMA target. |
| 236 | * Useful for holding code to do something appropriate |
| 237 | * after a kernel panic. |
| 238 | */ |
| 239 | static int __init setup_crashkernel(char *arg) |
| 240 | { |
| 241 | unsigned long size, base; |
| 242 | char *p; |
| 243 | if (!arg) |
| 244 | return -EINVAL; |
| 245 | size = memparse(arg, &p); |
| 246 | if (arg == p) |
| 247 | return -EINVAL; |
| 248 | if (*p == '@') { |
| 249 | base = memparse(p+1, &p); |
| 250 | /* FIXME: Do I want a sanity check to validate the |
| 251 | * memory range? Yes you do, but it's too early for |
| 252 | * e820 -AK */ |
| 253 | crashk_res.start = base; |
| 254 | crashk_res.end = base + size - 1; |
| 255 | } |
| 256 | return 0; |
| 257 | } |
| 258 | early_param("crashkernel", setup_crashkernel); |
| 259 | |