arch/x86_64/kernel/suspend.c

   1 /*
   2  * Suspend support specific for i386.
   3  *
   4  * Distribute under GPLv2
   5  *
   6  * Copyright (c) 2002 Pavel Machek <pavel@suse.cz>
   7  * Copyright (c) 2001 Patrick Mochel <mochel@osdl.org>
   8  */
   9
  10 #include <linux/smp.h>
  11 #include <linux/suspend.h>
  12 #include <asm/proto.h>
  13 #include <asm/page.h>
  14 #include <asm/pgtable.h>
  15
  16 struct saved_context saved_context;
  17
  18 unsigned long saved_context_eax, saved_context_ebx, saved_context_ecx, saved_context_edx;
  19 unsigned long saved_context_esp, saved_context_ebp, saved_context_esi, saved_context_edi;
  20 unsigned long saved_context_r08, saved_context_r09, saved_context_r10, saved_context_r11;
  21 unsigned long saved_context_r12, saved_context_r13, saved_context_r14, saved_context_r15;
  22 unsigned long saved_context_eflags;
  23
  24 void __save_processor_state(struct saved_context *ctxt)
  25 {
  26         kernel_fpu_begin();
  27
  28         /*
  29          * descriptor tables
  30          */
  31         asm volatile ("sgdt %0" : "=m" (ctxt->gdt_limit));
  32         asm volatile ("sidt %0" : "=m" (ctxt->idt_limit));
  33         asm volatile ("str %0"  : "=m" (ctxt->tr));
  34
  35         /* XMM0..XMM15 should be handled by kernel_fpu_begin(). */
  36         /* EFER should be constant for kernel version, no need to handle it. */
  37         /*
  38          * segment registers
  39          */
  40         asm volatile ("movw %%ds, %0" : "=m" (ctxt->ds));
  41         asm volatile ("movw %%es, %0" : "=m" (ctxt->es));
  42         asm volatile ("movw %%fs, %0" : "=m" (ctxt->fs));
  43         asm volatile ("movw %%gs, %0" : "=m" (ctxt->gs));
  44         asm volatile ("movw %%ss, %0" : "=m" (ctxt->ss));
  45
  46         rdmsrl(MSR_FS_BASE, ctxt->fs_base);
  47         rdmsrl(MSR_GS_BASE, ctxt->gs_base);
  48         rdmsrl(MSR_KERNEL_GS_BASE, ctxt->gs_kernel_base);
  49
  50         /*
  51          * control registers
  52          */
  53         asm volatile ("movq %%cr0, %0" : "=r" (ctxt->cr0));
  54         asm volatile ("movq %%cr2, %0" : "=r" (ctxt->cr2));
  55         asm volatile ("movq %%cr3, %0" : "=r" (ctxt->cr3));
  56         asm volatile ("movq %%cr4, %0" : "=r" (ctxt->cr4));
  57         asm volatile ("movq %%cr8, %0" : "=r" (ctxt->cr8));
  58 }
  59
  60 void save_processor_state(void)
  61 {
  62         __save_processor_state(&saved_context);
  63 }
  64
  65 static void do_fpu_end(void)
  66 {
  67         /*
  68          * Restore FPU regs if necessary
  69          */
  70         kernel_fpu_end();
  71 }
  72
  73 void __restore_processor_state(struct saved_context *ctxt)
  74 {
  75         /*
  76          * control registers
  77          */
  78         asm volatile ("movq %0, %%cr8" :: "r" (ctxt->cr8));
  79         asm volatile ("movq %0, %%cr4" :: "r" (ctxt->cr4));
  80         asm volatile ("movq %0, %%cr3" :: "r" (ctxt->cr3));
  81         asm volatile ("movq %0, %%cr2" :: "r" (ctxt->cr2));
  82         asm volatile ("movq %0, %%cr0" :: "r" (ctxt->cr0));
  83
  84         /*
  85          * now restore the descriptor tables to their proper values
  86          * ltr is done i fix_processor_context().
  87          */
  88         asm volatile ("lgdt %0" :: "m" (ctxt->gdt_limit));
  89         asm volatile ("lidt %0" :: "m" (ctxt->idt_limit));
  90
  91         /*
  92          * segment registers
  93          */
  94         asm volatile ("movw %0, %%ds" :: "r" (ctxt->ds));
  95         asm volatile ("movw %0, %%es" :: "r" (ctxt->es));
  96         asm volatile ("movw %0, %%fs" :: "r" (ctxt->fs));
  97         load_gs_index(ctxt->gs);
  98         asm volatile ("movw %0, %%ss" :: "r" (ctxt->ss));
  99
 100         wrmsrl(MSR_FS_BASE, ctxt->fs_base);
 101         wrmsrl(MSR_GS_BASE, ctxt->gs_base);
 102         wrmsrl(MSR_KERNEL_GS_BASE, ctxt->gs_kernel_base);
 103
 104         fix_processor_context();
 105
 106         do_fpu_end();
 107         mtrr_ap_init();
 108 }
 109
 110 void restore_processor_state(void)
 111 {
 112         __restore_processor_state(&saved_context);
 113 }
 114
 115 void fix_processor_context(void)
 116 {
 117         int cpu = smp_processor_id();
 118         struct tss_struct *t = &per_cpu(init_tss, cpu);
 119
 120         set_tss_desc(cpu,t);    /* This just modifies memory; should not be neccessary. But... This is neccessary, because 386 hardware has concept of busy TSS or some similar stupidity. */
 121
 122         cpu_gdt(cpu)[GDT_ENTRY_TSS].type = 9;
 123
 124         syscall_init();                         /* This sets MSR_*STAR and related */
 125         load_TR_desc();                         /* This does ltr */
 126         load_LDT(&current->active_mm->context); /* This does lldt */
 127
 128         /*
 129          * Now maybe reload the debug registers
 130          */
 131         if (current->thread.debugreg7){
 132                 loaddebug(&current->thread, 0);
 133                 loaddebug(&current->thread, 1);
 134                 loaddebug(&current->thread, 2);
 135                 loaddebug(&current->thread, 3);
 136                 /* no 4 and 5 */
 137                 loaddebug(&current->thread, 6);
 138                 loaddebug(&current->thread, 7);
 139         }
 140
 141 }
 142
 143 #ifdef CONFIG_SOFTWARE_SUSPEND
 144 /* Defined in arch/x86_64/kernel/suspend_asm.S */
 145 extern int restore_image(void);
 146
 147 pgd_t *temp_level4_pgt;
 148
 149 static int res_phys_pud_init(pud_t *pud, unsigned long address, unsigned long end)
 150 {
 151         long i, j;
 152
 153         i = pud_index(address);
 154         pud = pud + i;
 155         for (; i < PTRS_PER_PUD; pud++, i++) {
 156                 unsigned long paddr;
 157                 pmd_t *pmd;
 158
 159                 paddr = address + i*PUD_SIZE;
 160                 if (paddr >= end)
 161                         break;
 162
 163                 pmd = (pmd_t *)get_safe_page(GFP_ATOMIC);
 164                 if (!pmd)
 165                         return -ENOMEM;
 166                 set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE));
 167                 for (j = 0; j < PTRS_PER_PMD; pmd++, j++, paddr += PMD_SIZE) {
 168                         unsigned long pe;
 169
 170                         if (paddr >= end)
 171                                 break;
 172                         pe = _PAGE_NX | _PAGE_PSE | _KERNPG_TABLE | paddr;
 173                         pe &= __supported_pte_mask;
 174                         set_pmd(pmd, __pmd(pe));
 175                 }
 176         }
 177         return 0;
 178 }
 179
 180 static int set_up_temporary_mappings(void)
 181 {
 182         unsigned long start, end, next;
 183         int error;
 184
 185         temp_level4_pgt = (pgd_t *)get_safe_page(GFP_ATOMIC);
 186         if (!temp_level4_pgt)
 187                 return -ENOMEM;
 188
 189         /* It is safe to reuse the original kernel mapping */
 190         set_pgd(temp_level4_pgt + pgd_index(__START_KERNEL_map),
 191                 init_level4_pgt[pgd_index(__START_KERNEL_map)]);
 192
 193         /* Set up the direct mapping from scratch */
 194         start = (unsigned long)pfn_to_kaddr(0);
 195         end = (unsigned long)pfn_to_kaddr(end_pfn);
 196
 197         for (; start < end; start = next) {
 198                 pud_t *pud = (pud_t *)get_safe_page(GFP_ATOMIC);
 199                 if (!pud)
 200                         return -ENOMEM;
 201                 next = start + PGDIR_SIZE;
 202                 if (next > end)
 203                         next = end;
 204                 if ((error = res_phys_pud_init(pud, __pa(start), __pa(next))))
 205                         return error;
 206                 set_pgd(temp_level4_pgt + pgd_index(start),
 207                         mk_kernel_pgd(__pa(pud)));
 208         }
 209         return 0;
 210 }
 211
 212 int swsusp_arch_resume(void)
 213 {
 214         int error;
 215
 216         /* We have got enough memory and from now on we cannot recover */
 217         if ((error = set_up_temporary_mappings()))
 218                 return error;
 219         restore_image();
 220         return 0;
 221 }
 222 #endif /* CONFIG_SOFTWARE_SUSPEND */