[PATCH 3/6] x86: unify power/cpu_(32|64) regarding saving processorstate

From: Sergio Luis
Date: Sat Apr 04 2009 - 04:47:18 EST


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

In this step we do unify cpu_32.c and cpu_64.c functions that
work on saving the processor state.

Signed-off-by: Sergio Luis <sergio@xxxxxxxxxxxxxx>
Signed-off-by: Lauro Salmito <laurosalmito@xxxxxxxxx>
---
arch/x86/power/cpu_32.c | 48 +++++++++++++++++++++++++++++++++++++++++++++++
arch/x86/power/cpu_64.c | 29 +++++++++++++++++++++++++++-
2 files changed, 76 insertions(+), 1 deletions(-)

diff --git a/arch/x86/power/cpu_32.c b/arch/x86/power/cpu_32.c
index e4bdc2a..dd32ecc 100644
--- a/arch/x86/power/cpu_32.c
+++ b/arch/x86/power/cpu_32.c
@@ -31,25 +31,65 @@ static void fix_processor_context(void);
struct saved_context saved_context;
#endif

+/**
+ * __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)
{
+#ifdef CONFIG_X86_32
mtrr_save_fixed_ranges(NULL);
+#endif
kernel_fpu_begin();

/*
* descriptor tables
*/
+#ifdef CONFIG_X86_32
store_gdt(&ctxt->gdt);
store_idt(&ctxt->idt);
+#else
+/* CONFIG_X86_64 */
+ store_gdt((struct desc_ptr *)&ctxt->gdt_limit);
+ store_idt((struct desc_ptr *)&ctxt->idt_limit);
+#endif
store_tr(ctxt->tr);

+ /* XMM0..XMM15 should be handled by kernel_fpu_begin(). */
/*
* segment registers
*/
+#ifdef CONFIG_X86_32
savesegment(es, ctxt->es);
savesegment(fs, ctxt->fs);
savesegment(gs, ctxt->gs);
savesegment(ss, ctxt->ss);
+#else
+/* CONFIG_X86_64 */
+ 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);
+
+ rdmsrl(MSR_EFER, ctxt->efer);
+#endif

/*
* control registers
@@ -57,7 +97,13 @@ static void __save_processor_state(struct saved_context *ctxt)
ctxt->cr0 = read_cr0();
ctxt->cr2 = read_cr2();
ctxt->cr3 = read_cr3();
+#ifdef CONFIG_X86_32
ctxt->cr4 = read_cr4_safe();
+#else
+/* CONFIG_X86_64 */
+ ctxt->cr4 = read_cr4();
+ ctxt->cr8 = read_cr8();
+#endif
}

/* Needed by apm.c */
@@ -65,7 +111,9 @@ void save_processor_state(void)
{
__save_processor_state(&saved_context);
}
+#ifdef CONFIG_X86_32
EXPORT_SYMBOL(save_processor_state);
+#endif

static void do_fpu_end(void)
{
diff --git a/arch/x86/power/cpu_64.c b/arch/x86/power/cpu_64.c
index 1ee153e..5ababf8 100644
--- a/arch/x86/power/cpu_64.c
+++ b/arch/x86/power/cpu_64.c
@@ -49,19 +49,35 @@ struct saved_context saved_context;
*/
static void __save_processor_state(struct saved_context *ctxt)
{
+#ifdef CONFIG_X86_32
+ mtrr_save_fixed_ranges(NULL);
+#endif
kernel_fpu_begin();

/*
* descriptor tables
*/
+#ifdef CONFIG_X86_32
+ store_gdt(&ctxt->gdt);
+ store_idt(&ctxt->idt);
+#else
+/* CONFIG_X86_64 */
store_gdt((struct desc_ptr *)&ctxt->gdt_limit);
store_idt((struct desc_ptr *)&ctxt->idt_limit);
+#endif
store_tr(ctxt->tr);

/* XMM0..XMM15 should be handled by kernel_fpu_begin(). */
/*
* segment registers
*/
+#ifdef CONFIG_X86_32
+ savesegment(es, ctxt->es);
+ savesegment(fs, ctxt->fs);
+ savesegment(gs, ctxt->gs);
+ savesegment(ss, ctxt->ss);
+#else
+/* CONFIG_X86_64 */
asm volatile ("movw %%ds, %0" : "=m" (ctxt->ds));
asm volatile ("movw %%es, %0" : "=m" (ctxt->es));
asm volatile ("movw %%fs, %0" : "=m" (ctxt->fs));
@@ -73,21 +89,32 @@ static void __save_processor_state(struct saved_context *ctxt)
rdmsrl(MSR_KERNEL_GS_BASE, ctxt->gs_kernel_base);
mtrr_save_fixed_ranges(NULL);

+ rdmsrl(MSR_EFER, ctxt->efer);
+#endif
+
/*
* control registers
*/
- rdmsrl(MSR_EFER, ctxt->efer);
ctxt->cr0 = read_cr0();
ctxt->cr2 = read_cr2();
ctxt->cr3 = read_cr3();
+#ifdef CONFIG_X86_32
+ ctxt->cr4 = read_cr4_safe();
+#else
+/* CONFIG_X86_64 */
ctxt->cr4 = read_cr4();
ctxt->cr8 = read_cr8();
+#endif
}

+/* Needed by apm.c */
void save_processor_state(void)
{
__save_processor_state(&saved_context);
}
+#ifdef CONFIG_X86_32
+EXPORT_SYMBOL(save_processor_state);
+#endif

static void do_fpu_end(void)
{
--
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