summaryrefslogtreecommitdiffstats
path: root/arch/x86/xen/enlighten.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/x86/xen/enlighten.c')
-rw-r--r--arch/x86/xen/enlighten.c99
1 files changed, 95 insertions, 4 deletions
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 4172af8ceeb..b132ade26f7 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -62,6 +62,15 @@
#include <asm/reboot.h>
#include <asm/stackprotector.h>
#include <asm/hypervisor.h>
+#include <asm/mwait.h>
+
+#ifdef CONFIG_ACPI
+#include <linux/acpi.h>
+#include <asm/acpi.h>
+#include <acpi/pdc_intel.h>
+#include <acpi/processor.h>
+#include <xen/interface/platform.h>
+#endif
#include "xen-ops.h"
#include "mmu.h"
@@ -200,13 +209,17 @@ static void __init xen_banner(void)
static __read_mostly unsigned int cpuid_leaf1_edx_mask = ~0;
static __read_mostly unsigned int cpuid_leaf1_ecx_mask = ~0;
+static __read_mostly unsigned int cpuid_leaf1_ecx_set_mask;
+static __read_mostly unsigned int cpuid_leaf5_ecx_val;
+static __read_mostly unsigned int cpuid_leaf5_edx_val;
+
static void xen_cpuid(unsigned int *ax, unsigned int *bx,
unsigned int *cx, unsigned int *dx)
{
unsigned maskebx = ~0;
unsigned maskecx = ~0;
unsigned maskedx = ~0;
-
+ unsigned setecx = 0;
/*
* Mask out inconvenient features, to try and disable as many
* unsupported kernel subsystems as possible.
@@ -214,9 +227,18 @@ static void xen_cpuid(unsigned int *ax, unsigned int *bx,
switch (*ax) {
case 1:
maskecx = cpuid_leaf1_ecx_mask;
+ setecx = cpuid_leaf1_ecx_set_mask;
maskedx = cpuid_leaf1_edx_mask;
break;
+ case CPUID_MWAIT_LEAF:
+ /* Synthesize the values.. */
+ *ax = 0;
+ *bx = 0;
+ *cx = cpuid_leaf5_ecx_val;
+ *dx = cpuid_leaf5_edx_val;
+ return;
+
case 0xb:
/* Suppress extended topology stuff */
maskebx = 0;
@@ -232,9 +254,75 @@ static void xen_cpuid(unsigned int *ax, unsigned int *bx,
*bx &= maskebx;
*cx &= maskecx;
+ *cx |= setecx;
*dx &= maskedx;
+
}
+static bool __init xen_check_mwait(void)
+{
+#ifdef CONFIG_ACPI
+ struct xen_platform_op op = {
+ .cmd = XENPF_set_processor_pminfo,
+ .u.set_pminfo.id = -1,
+ .u.set_pminfo.type = XEN_PM_PDC,
+ };
+ uint32_t buf[3];
+ unsigned int ax, bx, cx, dx;
+ unsigned int mwait_mask;
+
+ /* We need to determine whether it is OK to expose the MWAIT
+ * capability to the kernel to harvest deeper than C3 states from ACPI
+ * _CST using the processor_harvest_xen.c module. For this to work, we
+ * need to gather the MWAIT_LEAF values (which the cstate.c code
+ * checks against). The hypervisor won't expose the MWAIT flag because
+ * it would break backwards compatibility; so we will find out directly
+ * from the hardware and hypercall.
+ */
+ if (!xen_initial_domain())
+ return false;
+
+ ax = 1;
+ cx = 0;
+
+ native_cpuid(&ax, &bx, &cx, &dx);
+
+ mwait_mask = (1 << (X86_FEATURE_EST % 32)) |
+ (1 << (X86_FEATURE_MWAIT % 32));
+
+ if ((cx & mwait_mask) != mwait_mask)
+ return false;
+
+ /* We need to emulate the MWAIT_LEAF and for that we need both
+ * ecx and edx. The hypercall provides only partial information.
+ */
+
+ ax = CPUID_MWAIT_LEAF;
+ bx = 0;
+ cx = 0;
+ dx = 0;
+
+ native_cpuid(&ax, &bx, &cx, &dx);
+
+ /* Ask the Hypervisor whether to clear ACPI_PDC_C_C2C3_FFH. If so,
+ * don't expose MWAIT_LEAF and let ACPI pick the IOPORT version of C3.
+ */
+ buf[0] = ACPI_PDC_REVISION_ID;
+ buf[1] = 1;
+ buf[2] = (ACPI_PDC_C_CAPABILITY_SMP | ACPI_PDC_EST_CAPABILITY_SWSMP);
+
+ set_xen_guest_handle(op.u.set_pminfo.pdc, buf);
+
+ if ((HYPERVISOR_dom0_op(&op) == 0) &&
+ (buf[2] & (ACPI_PDC_C_C1_FFH | ACPI_PDC_C_C2C3_FFH))) {
+ cpuid_leaf5_ecx_val = cx;
+ cpuid_leaf5_edx_val = dx;
+ }
+ return true;
+#else
+ return false;
+#endif
+}
static void __init xen_init_cpuid_mask(void)
{
unsigned int ax, bx, cx, dx;
@@ -261,6 +349,9 @@ static void __init xen_init_cpuid_mask(void)
/* Xen will set CR4.OSXSAVE if supported and not disabled by force */
if ((cx & xsave_mask) != xsave_mask)
cpuid_leaf1_ecx_mask &= ~xsave_mask; /* disable XSAVE & OSXSAVE */
+
+ if (xen_check_mwait())
+ cpuid_leaf1_ecx_set_mask = (1 << (X86_FEATURE_MWAIT % 32));
}
static void xen_set_debugreg(int reg, unsigned long val)
@@ -777,11 +868,11 @@ static DEFINE_PER_CPU(unsigned long, xen_cr0_value);
static unsigned long xen_read_cr0(void)
{
- unsigned long cr0 = percpu_read(xen_cr0_value);
+ unsigned long cr0 = this_cpu_read(xen_cr0_value);
if (unlikely(cr0 == 0)) {
cr0 = native_read_cr0();
- percpu_write(xen_cr0_value, cr0);
+ this_cpu_write(xen_cr0_value, cr0);
}
return cr0;
@@ -791,7 +882,7 @@ static void xen_write_cr0(unsigned long cr0)
{
struct multicall_space mcs;
- percpu_write(xen_cr0_value, cr0);
+ this_cpu_write(xen_cr0_value, cr0);
/* Only pay attention to cr0.TS; everything else is
ignored. */