[PATCH 4/6] x86: unify power/cpu_(32|64) regarding restoring processorstate

From: Sergio Luis
Date: Sat Apr 04 2009 - 04:48:04 EST

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@xxxxxxxxxxxxxx>
Signed-off-by: Lauro Salmito <laurosalmito@xxxxxxxxx>
---
arch/x86/power/cpu_32.c | 55 +++++++++++++++++++++-
arch/x86/power/cpu_64.c | 118 ++++++++++++++++++++++++++++++++--------------
2 files changed, 135 insertions(+), 38 deletions(-)

diff --git a/arch/x86/power/cpu_32.c b/arch/x86/power/cpu_32.c
index dd32ecc..ef656e2 100644
--- a/arch/x86/power/cpu_32.c
+++ b/arch/x86/power/cpu_32.c
@@ -26,8 +26,6 @@ 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

@@ -135,6 +133,11 @@ 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 */

@@ -142,6 +145,7 @@ 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);
@@ -149,18 +153,40 @@ 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);
@@ -169,12 +195,19 @@ 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);
@@ -185,6 +218,18 @@ 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.
@@ -193,9 +238,13 @@ 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 */
@@ -203,4 +252,6 @@ 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 5ababf8..8bd680a 100644
--- a/arch/x86/power/cpu_64.c
+++ b/arch/x86/power/cpu_64.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

@@ -119,11 +117,57 @@ 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()
@@ -134,9 +178,16 @@ 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);
@@ -145,13 +196,31 @@ 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));
@@ -161,6 +230,7 @@ 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.
@@ -172,41 +242,17 @@ 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
--
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