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-rw-r--r--arch/x86/power/cpu_64.c166
1 files changed, 166 insertions, 0 deletions
diff --git a/arch/x86/power/cpu_64.c b/arch/x86/power/cpu_64.c
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+/*
+ * 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(&current->active_mm->context); /* This does lldt */
+
+ /*
+ * Now maybe reload the debug registers
+ */
+ if (current->thread.debugreg7){
+ loaddebug(&current->thread, 0);
+ loaddebug(&current->thread, 1);
+ loaddebug(&current->thread, 2);
+ loaddebug(&current->thread, 3);
+ /* no 4 and 5 */
+ loaddebug(&current->thread, 6);
+ loaddebug(&current->thread, 7);
+ }
+}
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