x86: unify power/cpu_(32|64) regarding restoring processor state

In this step we do unify cpu_32.c and cpu_64.c functions that
work on restoring the saved processor state. Also, we do
eliminate the forward declaration of fix_processor_context()
for X86_64, as it's not needed anymore.

Signed-off-by: Sergio Luis <sergio@larces.uece.br>
Signed-off-by: Lauro Salmito <laurosalmito@gmail.com>
Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>

2 files changed, 135 insertions, 38 deletions

diff --git a/arch/x86/power/cpu_32.c b/arch/x86/power/cpu_32.c
index 294e78baff75..29b9c0a1ca62 100644
--- a/arch/x86/power/cpu_32.c
+++ b/arch/x86/power/cpu_32.c
@@ -27,8 +27,6 @@ unsigned long saved_context_esi, saved_context_edi;
 unsigned long saved_context_eflags;
 #else
 /* CONFIG_X86_64 */
-static void fix_processor_context(void);
-
 struct saved_context saved_context;
 #endif
 
@@ -136,6 +134,11 @@ static void fix_processor_context(void)
                                  * similar stupidity.
                                  */
 
+#ifdef CONFIG_X86_64
+        get_cpu_gdt_table(cpu)[GDT_ENTRY_TSS].type = 9;
+
+        syscall_init();                         /* This sets MSR_*STAR and related */
+#endif
         load_TR_desc();                         /* This does ltr */
         load_LDT(&current->active_mm->context); /* This does lldt */
 
@@ -143,6 +146,7 @@ static void fix_processor_context(void)
          * Now maybe reload the debug registers
          */
         if (current->thread.debugreg7) {
+#ifdef CONFIG_X86_32
                 set_debugreg(current->thread.debugreg0, 0);
                 set_debugreg(current->thread.debugreg1, 1);
                 set_debugreg(current->thread.debugreg2, 2);
@@ -150,18 +154,40 @@ static void fix_processor_context(void)
                 /* no 4 and 5 */
                 set_debugreg(current->thread.debugreg6, 6);
                 set_debugreg(current->thread.debugreg7, 7);
+#else
+                /* CONFIG_X86_64 */
+                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);
+#endif
         }
 
 }
 
+/**
+ *      __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
          */
         /* cr4 was introduced in the Pentium CPU */
+#ifdef CONFIG_X86_32
         if (ctxt->cr4)
                 write_cr4(ctxt->cr4);
+#else
+/* CONFIG X86_64 */
+        wrmsrl(MSR_EFER, ctxt->efer);
+        write_cr8(ctxt->cr8);
+        write_cr4(ctxt->cr4);
+#endif
         write_cr3(ctxt->cr3);
         write_cr2(ctxt->cr2);
         write_cr0(ctxt->cr0);
@@ -170,12 +196,19 @@ static void __restore_processor_state(struct saved_context *ctxt)
          * now restore the descriptor tables to their proper values
          * ltr is done i fix_processor_context().
          */
+#ifdef CONFIG_X86_32
         load_gdt(&ctxt->gdt);
         load_idt(&ctxt->idt);
+#else
+/* CONFIG_X86_64 */
+        load_gdt((const struct desc_ptr *)&ctxt->gdt_limit);
+        load_idt((const struct desc_ptr *)&ctxt->idt_limit);
+#endif
 
         /*
          * segment registers
          */
+#ifdef CONFIG_X86_32
         loadsegment(es, ctxt->es);
         loadsegment(fs, ctxt->fs);
         loadsegment(gs, ctxt->gs);
@@ -186,6 +219,18 @@ static void __restore_processor_state(struct saved_context *ctxt)
          */
         if (boot_cpu_has(X86_FEATURE_SEP))
                 enable_sep_cpu();
+#else
+/* CONFIG_X86_64 */
+        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);
+#endif
 
         /*
          * restore XCR0 for xsave capable cpu's.
@@ -194,9 +239,13 @@ static void __restore_processor_state(struct saved_context *ctxt)
                 xsetbv(XCR_XFEATURE_ENABLED_MASK, pcntxt_mask);
 
         fix_processor_context();
+
         do_fpu_end();
         mtrr_ap_init();
+
+#ifdef CONFIG_X86_32
         mcheck_init(&boot_cpu_data);
+#endif
 }
 
 /* Needed by apm.c */
@@ -204,4 +253,6 @@ void restore_processor_state(void)
 {
         __restore_processor_state(&saved_context);
 }
+#ifdef CONFIG_X86_32
 EXPORT_SYMBOL(restore_processor_state);
+#endif
diff --git a/arch/x86/power/cpu_64.c b/arch/x86/power/cpu_64.c
index 11ea7d0ba5d9..5c8bdc002b8b 100644
--- a/arch/x86/power/cpu_64.c
+++ b/arch/x86/power/cpu_64.c
@@ -28,8 +28,6 @@ unsigned long saved_context_esi, saved_context_edi;
 unsigned long saved_context_eflags;
 #else
 /* CONFIG_X86_64 */
-static void fix_processor_context(void);
-
 struct saved_context saved_context;
 #endif
 
@@ -120,11 +118,57 @@ EXPORT_SYMBOL(save_processor_state);
 static void do_fpu_end(void)
 {
         /*
-         * Restore FPU regs if necessary
+         * Restore FPU regs if necessary.
          */
         kernel_fpu_end();
 }
 
+static void fix_processor_context(void)
+{
+        int cpu = smp_processor_id();
+        struct tss_struct *t = &per_cpu(init_tss, cpu);
+
+        set_tss_desc(cpu, t);   /*
+                                 * This just modifies memory; should not be
+                                 * necessary. But... This is necessary, because
+                                 * 386 hardware has concept of busy TSS or some
+                                 * similar stupidity.
+                                 */
+
+#ifdef CONFIG_X86_64
+        get_cpu_gdt_table(cpu)[GDT_ENTRY_TSS].type = 9;
+
+        syscall_init();                         /* This sets MSR_*STAR and related */
+#endif
+        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) {
+#ifdef CONFIG_X86_32
+                set_debugreg(current->thread.debugreg0, 0);
+                set_debugreg(current->thread.debugreg1, 1);
+                set_debugreg(current->thread.debugreg2, 2);
+                set_debugreg(current->thread.debugreg3, 3);
+                /* no 4 and 5 */
+                set_debugreg(current->thread.debugreg6, 6);
+                set_debugreg(current->thread.debugreg7, 7);
+#else
+                /* CONFIG_X86_64 */
+                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);
+#endif
+        }
+
+}
+
 /**
  *      __restore_processor_state - restore the contents of CPU registers saved
  *              by __save_processor_state()
@@ -135,9 +179,16 @@ static void __restore_processor_state(struct saved_context *ctxt)
         /*
          * control registers
          */
+        /* cr4 was introduced in the Pentium CPU */
+#ifdef CONFIG_X86_32
+        if (ctxt->cr4)
+                write_cr4(ctxt->cr4);
+#else
+/* CONFIG X86_64 */
         wrmsrl(MSR_EFER, ctxt->efer);
         write_cr8(ctxt->cr8);
         write_cr4(ctxt->cr4);
+#endif
         write_cr3(ctxt->cr3);
         write_cr2(ctxt->cr2);
         write_cr0(ctxt->cr0);
@@ -146,13 +197,31 @@ static void __restore_processor_state(struct saved_context *ctxt)
          * now restore the descriptor tables to their proper values
          * ltr is done i fix_processor_context().
          */
+#ifdef CONFIG_X86_32
+        load_gdt(&ctxt->gdt);
+        load_idt(&ctxt->idt);
+#else
+/* CONFIG_X86_64 */
         load_gdt((const struct desc_ptr *)&ctxt->gdt_limit);
         load_idt((const struct desc_ptr *)&ctxt->idt_limit);
-
+#endif
 
         /*
          * segment registers
          */
+#ifdef CONFIG_X86_32
+        loadsegment(es, ctxt->es);
+        loadsegment(fs, ctxt->fs);
+        loadsegment(gs, ctxt->gs);
+        loadsegment(ss, ctxt->ss);
+
+        /*
+         * sysenter MSRs
+         */
+        if (boot_cpu_has(X86_FEATURE_SEP))
+                enable_sep_cpu();
+#else
+/* CONFIG_X86_64 */
         asm volatile ("movw %0, %%ds" :: "r" (ctxt->ds));
         asm volatile ("movw %0, %%es" :: "r" (ctxt->es));
         asm volatile ("movw %0, %%fs" :: "r" (ctxt->fs));
@@ -162,6 +231,7 @@ static void __restore_processor_state(struct saved_context *ctxt)
         wrmsrl(MSR_FS_BASE, ctxt->fs_base);
         wrmsrl(MSR_GS_BASE, ctxt->gs_base);
         wrmsrl(MSR_KERNEL_GS_BASE, ctxt->gs_kernel_base);
+#endif
 
         /*
          * restore XCR0 for xsave capable cpu's.
@@ -173,41 +243,17 @@ static void __restore_processor_state(struct saved_context *ctxt)
 
         do_fpu_end();
         mtrr_ap_init();
+
+#ifdef CONFIG_X86_32
+        mcheck_init(&boot_cpu_data);
+#endif
 }
 
+/* Needed by apm.c */
 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);
-        }
-}
+#ifdef CONFIG_X86_32
+EXPORT_SYMBOL(restore_processor_state);
+#endif