| 1 | /* |
| 2 | * Copyright 2010 Tilera Corporation. All Rights Reserved. |
| 3 | * |
| 4 | * This program is free software; you can redistribute it and/or |
| 5 | * modify it under the terms of the GNU General Public License |
| 6 | * as published by the Free Software Foundation, version 2. |
| 7 | * |
| 8 | * This program is distributed in the hope that it will be useful, but |
| 9 | * WITHOUT ANY WARRANTY; without even the implied warranty of |
| 10 | * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or |
| 11 | * NON INFRINGEMENT. See the GNU General Public License for |
| 12 | * more details. |
| 13 | * |
| 14 | * based on machine_kexec.c from other architectures in linux-2.6.18 |
| 15 | */ |
| 16 | |
| 17 | #include <linux/mm.h> |
| 18 | #include <linux/kexec.h> |
| 19 | #include <linux/delay.h> |
| 20 | #include <linux/reboot.h> |
| 21 | #include <linux/errno.h> |
| 22 | #include <linux/vmalloc.h> |
| 23 | #include <linux/cpumask.h> |
| 24 | #include <linux/kernel.h> |
| 25 | #include <linux/elf.h> |
| 26 | #include <linux/highmem.h> |
| 27 | #include <linux/mmu_context.h> |
| 28 | #include <linux/io.h> |
| 29 | #include <linux/timex.h> |
| 30 | #include <asm/pgtable.h> |
| 31 | #include <asm/pgalloc.h> |
| 32 | #include <asm/cacheflush.h> |
| 33 | #include <asm/checksum.h> |
| 34 | #include <hv/hypervisor.h> |
| 35 | |
| 36 | |
| 37 | /* |
| 38 | * This stuff is not in elf.h and is not in any other kernel include. |
| 39 | * This stuff is needed below in the little boot notes parser to |
| 40 | * extract the command line so we can pass it to the hypervisor. |
| 41 | */ |
| 42 | struct Elf32_Bhdr { |
| 43 | Elf32_Word b_signature; |
| 44 | Elf32_Word b_size; |
| 45 | Elf32_Half b_checksum; |
| 46 | Elf32_Half b_records; |
| 47 | }; |
| 48 | #define ELF_BOOT_MAGIC 0x0E1FB007 |
| 49 | #define EBN_COMMAND_LINE 0x00000004 |
| 50 | #define roundupsz(X) (((X) + 3) & ~3) |
| 51 | |
| 52 | /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */ |
| 53 | |
| 54 | |
| 55 | void machine_shutdown(void) |
| 56 | { |
| 57 | /* |
| 58 | * Normally we would stop all the other processors here, but |
| 59 | * the check in machine_kexec_prepare below ensures we'll only |
| 60 | * get this far if we've been booted with "nosmp" on the |
| 61 | * command line or without CONFIG_SMP so there's nothing to do |
| 62 | * here (for now). |
| 63 | */ |
| 64 | } |
| 65 | |
| 66 | void machine_crash_shutdown(struct pt_regs *regs) |
| 67 | { |
| 68 | /* |
| 69 | * Cannot happen. This type of kexec is disabled on this |
| 70 | * architecture (and enforced in machine_kexec_prepare below). |
| 71 | */ |
| 72 | } |
| 73 | |
| 74 | |
| 75 | int machine_kexec_prepare(struct kimage *image) |
| 76 | { |
| 77 | if (num_online_cpus() > 1) { |
| 78 | pr_warning("%s: detected attempt to kexec " |
| 79 | "with num_online_cpus() > 1\n", |
| 80 | __func__); |
| 81 | return -ENOSYS; |
| 82 | } |
| 83 | if (image->type != KEXEC_TYPE_DEFAULT) { |
| 84 | pr_warning("%s: detected attempt to kexec " |
| 85 | "with unsupported type: %d\n", |
| 86 | __func__, |
| 87 | image->type); |
| 88 | return -ENOSYS; |
| 89 | } |
| 90 | return 0; |
| 91 | } |
| 92 | |
| 93 | void machine_kexec_cleanup(struct kimage *image) |
| 94 | { |
| 95 | /* |
| 96 | * We did nothing in machine_kexec_prepare, |
| 97 | * so we have nothing to do here. |
| 98 | */ |
| 99 | } |
| 100 | |
| 101 | /* |
| 102 | * If we can find elf boot notes on this page, return the command |
| 103 | * line. Otherwise, silently return null. Somewhat kludgy, but no |
| 104 | * good way to do this without significantly rearchitecting the |
| 105 | * architecture-independent kexec code. |
| 106 | */ |
| 107 | |
| 108 | static unsigned char *kexec_bn2cl(void *pg) |
| 109 | { |
| 110 | struct Elf32_Bhdr *bhdrp; |
| 111 | Elf32_Nhdr *nhdrp; |
| 112 | unsigned char *desc; |
| 113 | unsigned char *command_line; |
| 114 | __sum16 csum; |
| 115 | |
| 116 | bhdrp = (struct Elf32_Bhdr *) pg; |
| 117 | |
| 118 | /* |
| 119 | * This routine is invoked for every source page, so make |
| 120 | * sure to quietly ignore every impossible page. |
| 121 | */ |
| 122 | if (bhdrp->b_signature != ELF_BOOT_MAGIC || |
| 123 | bhdrp->b_size > PAGE_SIZE) |
| 124 | return 0; |
| 125 | |
| 126 | /* |
| 127 | * If we get a checksum mismatch, warn with the checksum |
| 128 | * so we can diagnose better. |
| 129 | */ |
| 130 | csum = ip_compute_csum(pg, bhdrp->b_size); |
| 131 | if (csum != 0) { |
| 132 | pr_warning("%s: bad checksum %#x (size %d)\n", |
| 133 | __func__, csum, bhdrp->b_size); |
| 134 | return 0; |
| 135 | } |
| 136 | |
| 137 | nhdrp = (Elf32_Nhdr *) (bhdrp + 1); |
| 138 | |
| 139 | while (nhdrp->n_type != EBN_COMMAND_LINE) { |
| 140 | |
| 141 | desc = (unsigned char *) (nhdrp + 1); |
| 142 | desc += roundupsz(nhdrp->n_descsz); |
| 143 | |
| 144 | nhdrp = (Elf32_Nhdr *) desc; |
| 145 | |
| 146 | /* still in bounds? */ |
| 147 | if ((unsigned char *) (nhdrp + 1) > |
| 148 | ((unsigned char *) pg) + bhdrp->b_size) { |
| 149 | |
| 150 | pr_info("%s: out of bounds\n", __func__); |
| 151 | return 0; |
| 152 | } |
| 153 | } |
| 154 | |
| 155 | command_line = (unsigned char *) (nhdrp + 1); |
| 156 | desc = command_line; |
| 157 | |
| 158 | while (*desc != '\0') { |
| 159 | desc++; |
| 160 | if (((unsigned long)desc & PAGE_MASK) != (unsigned long)pg) { |
| 161 | pr_info("%s: ran off end of page\n", |
| 162 | __func__); |
| 163 | return 0; |
| 164 | } |
| 165 | } |
| 166 | |
| 167 | return command_line; |
| 168 | } |
| 169 | |
| 170 | static void kexec_find_and_set_command_line(struct kimage *image) |
| 171 | { |
| 172 | kimage_entry_t *ptr, entry; |
| 173 | |
| 174 | unsigned char *command_line = 0; |
| 175 | unsigned char *r; |
| 176 | HV_Errno hverr; |
| 177 | |
| 178 | for (ptr = &image->head; |
| 179 | (entry = *ptr) && !(entry & IND_DONE); |
| 180 | ptr = (entry & IND_INDIRECTION) ? |
| 181 | phys_to_virt((entry & PAGE_MASK)) : ptr + 1) { |
| 182 | |
| 183 | if ((entry & IND_SOURCE)) { |
| 184 | void *va = |
| 185 | kmap_atomic_pfn(entry >> PAGE_SHIFT); |
| 186 | r = kexec_bn2cl(va); |
| 187 | if (r) { |
| 188 | command_line = r; |
| 189 | break; |
| 190 | } |
| 191 | kunmap_atomic(va); |
| 192 | } |
| 193 | } |
| 194 | |
| 195 | if (command_line != 0) { |
| 196 | pr_info("setting new command line to \"%s\"\n", |
| 197 | command_line); |
| 198 | |
| 199 | hverr = hv_set_command_line( |
| 200 | (HV_VirtAddr) command_line, strlen(command_line)); |
| 201 | kunmap_atomic(command_line); |
| 202 | } else { |
| 203 | pr_info("%s: no command line found; making empty\n", |
| 204 | __func__); |
| 205 | hverr = hv_set_command_line((HV_VirtAddr) command_line, 0); |
| 206 | } |
| 207 | if (hverr) |
| 208 | pr_warning("%s: hv_set_command_line returned error: %d\n", |
| 209 | __func__, hverr); |
| 210 | } |
| 211 | |
| 212 | /* |
| 213 | * The kexec code range-checks all its PAs, so to avoid having it run |
| 214 | * amok and allocate memory and then sequester it from every other |
| 215 | * controller, we force it to come from controller zero. We also |
| 216 | * disable the oom-killer since if we do end up running out of memory, |
| 217 | * that almost certainly won't help. |
| 218 | */ |
| 219 | struct page *kimage_alloc_pages_arch(gfp_t gfp_mask, unsigned int order) |
| 220 | { |
| 221 | gfp_mask |= __GFP_THISNODE | __GFP_NORETRY; |
| 222 | return alloc_pages_node(0, gfp_mask, order); |
| 223 | } |
| 224 | |
| 225 | static void setup_quasi_va_is_pa(void) |
| 226 | { |
| 227 | HV_PTE *pgtable; |
| 228 | HV_PTE pte; |
| 229 | int i; |
| 230 | |
| 231 | /* |
| 232 | * Flush our TLB to prevent conflicts between the previous contents |
| 233 | * and the new stuff we're about to add. |
| 234 | */ |
| 235 | local_flush_tlb_all(); |
| 236 | |
| 237 | /* setup VA is PA, at least up to PAGE_OFFSET */ |
| 238 | |
| 239 | pgtable = (HV_PTE *)current->mm->pgd; |
| 240 | pte = hv_pte(_PAGE_KERNEL | _PAGE_HUGE_PAGE); |
| 241 | pte = hv_pte_set_mode(pte, HV_PTE_MODE_CACHE_NO_L3); |
| 242 | |
| 243 | for (i = 0; i < pgd_index(PAGE_OFFSET); i++) { |
| 244 | unsigned long pfn = i << (HPAGE_SHIFT - PAGE_SHIFT); |
| 245 | if (pfn_valid(pfn)) |
| 246 | __set_pte(&pgtable[i], pfn_pte(pfn, pte)); |
| 247 | } |
| 248 | } |
| 249 | |
| 250 | |
| 251 | void machine_kexec(struct kimage *image) |
| 252 | { |
| 253 | void *reboot_code_buffer; |
| 254 | void (*rnk)(unsigned long, void *, unsigned long) |
| 255 | ATTRIB_NORET; |
| 256 | |
| 257 | /* Mask all interrupts before starting to reboot. */ |
| 258 | interrupt_mask_set_mask(~0ULL); |
| 259 | |
| 260 | kexec_find_and_set_command_line(image); |
| 261 | |
| 262 | /* |
| 263 | * Adjust the home caching of the control page to be cached on |
| 264 | * this cpu, and copy the assembly helper into the control |
| 265 | * code page, which we map in the vmalloc area. |
| 266 | */ |
| 267 | homecache_change_page_home(image->control_code_page, 0, |
| 268 | smp_processor_id()); |
| 269 | reboot_code_buffer = vmap(&image->control_code_page, 1, 0, |
| 270 | __pgprot(_PAGE_KERNEL | _PAGE_EXECUTABLE)); |
| 271 | memcpy(reboot_code_buffer, relocate_new_kernel, |
| 272 | relocate_new_kernel_size); |
| 273 | __flush_icache_range( |
| 274 | (unsigned long) reboot_code_buffer, |
| 275 | (unsigned long) reboot_code_buffer + relocate_new_kernel_size); |
| 276 | |
| 277 | setup_quasi_va_is_pa(); |
| 278 | |
| 279 | /* now call it */ |
| 280 | rnk = reboot_code_buffer; |
| 281 | (*rnk)(image->head, reboot_code_buffer, image->start); |
| 282 | } |