Merge tag 'stable/for-linus-3.4-tag' of git://git.kernel.org/pub/scm/linux/kernel...

[firefly-linux-kernel-4.4.55.git] / arch / x86 / xen / enlighten.c

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 4172af8ceeb363d06912af15bf89e8508752b794..b132ade26f778f2cfec7c2d5c7b6db48afe424d5 100644 (file)
--- 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. */