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-rw-r--r--arch/x86/power/cpu.c92
1 files changed, 92 insertions, 0 deletions
diff --git a/arch/x86/power/cpu.c b/arch/x86/power/cpu.c
index 9ab52791fed5..d5f64996394a 100644
--- a/arch/x86/power/cpu.c
+++ b/arch/x86/power/cpu.c
@@ -23,6 +23,7 @@
#include <asm/debugreg.h>
#include <asm/cpu.h>
#include <asm/mmu_context.h>
+#include <linux/dmi.h>
#ifdef CONFIG_X86_32
__visible unsigned long saved_context_ebx;
@@ -32,6 +33,29 @@ __visible unsigned long saved_context_eflags;
#endif
struct saved_context saved_context;
+static void msr_save_context(struct saved_context *ctxt)
+{
+ struct saved_msr *msr = ctxt->saved_msrs.array;
+ struct saved_msr *end = msr + ctxt->saved_msrs.num;
+
+ while (msr < end) {
+ msr->valid = !rdmsrl_safe(msr->info.msr_no, &msr->info.reg.q);
+ msr++;
+ }
+}
+
+static void msr_restore_context(struct saved_context *ctxt)
+{
+ struct saved_msr *msr = ctxt->saved_msrs.array;
+ struct saved_msr *end = msr + ctxt->saved_msrs.num;
+
+ while (msr < end) {
+ if (msr->valid)
+ wrmsrl(msr->info.msr_no, msr->info.reg.q);
+ msr++;
+ }
+}
+
/**
* __save_processor_state - save CPU registers before creating a
* hibernation image and before restoring the memory state from it
@@ -111,6 +135,7 @@ static void __save_processor_state(struct saved_context *ctxt)
#endif
ctxt->misc_enable_saved = !rdmsrl_safe(MSR_IA32_MISC_ENABLE,
&ctxt->misc_enable);
+ msr_save_context(ctxt);
}
/* Needed by apm.c */
@@ -229,6 +254,7 @@ static void notrace __restore_processor_state(struct saved_context *ctxt)
x86_platform.restore_sched_clock_state();
mtrr_bp_restore();
perf_restore_debug_store();
+ msr_restore_context(ctxt);
}
/* Needed by apm.c */
@@ -320,3 +346,69 @@ static int __init bsp_pm_check_init(void)
}
core_initcall(bsp_pm_check_init);
+
+static int msr_init_context(const u32 *msr_id, const int total_num)
+{
+ int i = 0;
+ struct saved_msr *msr_array;
+
+ if (saved_context.saved_msrs.array || saved_context.saved_msrs.num > 0) {
+ pr_err("x86/pm: MSR quirk already applied, please check your DMI match table.\n");
+ return -EINVAL;
+ }
+
+ msr_array = kmalloc_array(total_num, sizeof(struct saved_msr), GFP_KERNEL);
+ if (!msr_array) {
+ pr_err("x86/pm: Can not allocate memory to save/restore MSRs during suspend.\n");
+ return -ENOMEM;
+ }
+
+ for (i = 0; i < total_num; i++) {
+ msr_array[i].info.msr_no = msr_id[i];
+ msr_array[i].valid = false;
+ msr_array[i].info.reg.q = 0;
+ }
+ saved_context.saved_msrs.num = total_num;
+ saved_context.saved_msrs.array = msr_array;
+
+ return 0;
+}
+
+/*
+ * The following section is a quirk framework for problematic BIOSen:
+ * Sometimes MSRs are modified by the BIOSen after suspended to
+ * RAM, this might cause unexpected behavior after wakeup.
+ * Thus we save/restore these specified MSRs across suspend/resume
+ * in order to work around it.
+ *
+ * For any further problematic BIOSen/platforms,
+ * please add your own function similar to msr_initialize_bdw.
+ */
+static int msr_initialize_bdw(const struct dmi_system_id *d)
+{
+ /* Add any extra MSR ids into this array. */
+ u32 bdw_msr_id[] = { MSR_IA32_THERM_CONTROL };
+
+ pr_info("x86/pm: %s detected, MSR saving is needed during suspending.\n", d->ident);
+ return msr_init_context(bdw_msr_id, ARRAY_SIZE(bdw_msr_id));
+}
+
+static struct dmi_system_id msr_save_dmi_table[] = {
+ {
+ .callback = msr_initialize_bdw,
+ .ident = "BROADWELL BDX_EP",
+ .matches = {
+ DMI_MATCH(DMI_PRODUCT_NAME, "GRANTLEY"),
+ DMI_MATCH(DMI_PRODUCT_VERSION, "E63448-400"),
+ },
+ },
+ {}
+};
+
+static int pm_check_save_msr(void)
+{
+ dmi_check_system(msr_save_dmi_table);
+ return 0;
+}
+
+device_initcall(pm_check_save_msr);