diff options
Diffstat (limited to 'arch/x86/power/cpu_64.c')
| -rw-r--r-- | arch/x86/power/cpu_64.c | 166 |
1 files changed, 166 insertions, 0 deletions
diff --git a/arch/x86/power/cpu_64.c b/arch/x86/power/cpu_64.c new file mode 100644 index 00000000000..66bdfb591fd --- /dev/null +++ b/arch/x86/power/cpu_64.c @@ -0,0 +1,166 @@ +/* + * Suspend and hibernation support for x86-64 + * + * Distribute under GPLv2 + * + * Copyright (c) 2007 Rafael J. Wysocki <rjw@sisk.pl> + * Copyright (c) 2002 Pavel Machek <pavel@suse.cz> + * Copyright (c) 2001 Patrick Mochel <mochel@osdl.org> + */ + +#include <linux/smp.h> +#include <linux/suspend.h> +#include <asm/proto.h> +#include <asm/page.h> +#include <asm/pgtable.h> +#include <asm/mtrr.h> + +static void fix_processor_context(void); + +struct saved_context saved_context; + +/** + * __save_processor_state - save CPU registers before creating a + * hibernation image and before restoring the memory state from it + * @ctxt - structure to store the registers contents in + * + * NOTE: If there is a CPU register the modification of which by the + * boot kernel (ie. the kernel used for loading the hibernation image) + * might affect the operations of the restored target kernel (ie. the one + * saved in the hibernation image), then its contents must be saved by this + * function. In other words, if kernel A is hibernated and different + * kernel B is used for loading the hibernation image into memory, the + * kernel A's __save_processor_state() function must save all registers + * needed by kernel A, so that it can operate correctly after the resume + * regardless of what kernel B does in the meantime. + */ +static void __save_processor_state(struct saved_context *ctxt) +{ + kernel_fpu_begin(); + + /* + * descriptor tables + */ + store_gdt((struct desc_ptr *)&ctxt->gdt_limit); + store_idt((struct desc_ptr *)&ctxt->idt_limit); + store_tr(ctxt->tr); + + /* XMM0..XMM15 should be handled by kernel_fpu_begin(). */ + /* + * segment registers + */ + asm volatile ("movw %%ds, %0" : "=m" (ctxt->ds)); + asm volatile ("movw %%es, %0" : "=m" (ctxt->es)); + asm volatile ("movw %%fs, %0" : "=m" (ctxt->fs)); + asm volatile ("movw %%gs, %0" : "=m" (ctxt->gs)); + asm volatile ("movw %%ss, %0" : "=m" (ctxt->ss)); + + rdmsrl(MSR_FS_BASE, ctxt->fs_base); + rdmsrl(MSR_GS_BASE, ctxt->gs_base); + rdmsrl(MSR_KERNEL_GS_BASE, ctxt->gs_kernel_base); + mtrr_save_fixed_ranges(NULL); + + /* + * control registers + */ + rdmsrl(MSR_EFER, ctxt->efer); + ctxt->cr0 = read_cr0(); + ctxt->cr2 = read_cr2(); + ctxt->cr3 = read_cr3(); + ctxt->cr4 = read_cr4(); + ctxt->cr8 = read_cr8(); +} + +void save_processor_state(void) +{ + __save_processor_state(&saved_context); +} + +static void do_fpu_end(void) +{ + /* + * Restore FPU regs if necessary + */ + kernel_fpu_end(); +} + +/** + * __restore_processor_state - restore the contents of CPU registers saved + * by __save_processor_state() + * @ctxt - structure to load the registers contents from + */ +static void __restore_processor_state(struct saved_context *ctxt) +{ + /* + * control registers + */ + wrmsrl(MSR_EFER, ctxt->efer); + write_cr8(ctxt->cr8); + write_cr4(ctxt->cr4); + write_cr3(ctxt->cr3); + write_cr2(ctxt->cr2); + write_cr0(ctxt->cr0); + + /* + * now restore the descriptor tables to their proper values + * ltr is done i fix_processor_context(). + */ + load_gdt((const struct desc_ptr *)&ctxt->gdt_limit); + load_idt((const struct desc_ptr *)&ctxt->idt_limit); + + + /* + * segment registers + */ + asm volatile ("movw %0, %%ds" :: "r" (ctxt->ds)); + asm volatile ("movw %0, %%es" :: "r" (ctxt->es)); + asm volatile ("movw %0, %%fs" :: "r" (ctxt->fs)); + load_gs_index(ctxt->gs); + asm volatile ("movw %0, %%ss" :: "r" (ctxt->ss)); + + wrmsrl(MSR_FS_BASE, ctxt->fs_base); + wrmsrl(MSR_GS_BASE, ctxt->gs_base); + wrmsrl(MSR_KERNEL_GS_BASE, ctxt->gs_kernel_base); + + fix_processor_context(); + + do_fpu_end(); + mtrr_ap_init(); +} + +void restore_processor_state(void) +{ + __restore_processor_state(&saved_context); +} + +static void fix_processor_context(void) +{ + int cpu = smp_processor_id(); + struct tss_struct *t = &per_cpu(init_tss, cpu); + + /* + * This just modifies memory; should not be necessary. But... This + * is necessary, because 386 hardware has concept of busy TSS or some + * similar stupidity. + */ + set_tss_desc(cpu, t); + + get_cpu_gdt_table(cpu)[GDT_ENTRY_TSS].type = 9; + + syscall_init(); /* This sets MSR_*STAR and related */ + load_TR_desc(); /* This does ltr */ + load_LDT(¤t->active_mm->context); /* This does lldt */ + + /* + * Now maybe reload the debug registers + */ + if (current->thread.debugreg7){ + loaddebug(¤t->thread, 0); + loaddebug(¤t->thread, 1); + loaddebug(¤t->thread, 2); + loaddebug(¤t->thread, 3); + /* no 4 and 5 */ + loaddebug(¤t->thread, 6); + loaddebug(¤t->thread, 7); + } +} |