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

Pull xen updates from Konrad Rzeszutek Wilk:
 "which has three neat features:

   - PV multiconsole support, so that there can be hvc1, hvc2, etc; This
     can be used in HVM and in PV mode.

   - P-state and C-state power management driver that uploads said power
     management data to the hypervisor.  It also inhibits cpufreq
     scaling drivers to load so that only the hypervisor can make power
     management decisions - fixing a weird perf bug.

     There is one thing in the Kconfig that you won't like: "default y
     if (X86_ACPI_CPUFREQ = y || X86_POWERNOW_K8 = y)" (note, that it
     all depends on CONFIG_XEN which depends on CONFIG_PARAVIRT which by
     default is off).  I've a fix to convert that boolean expression
     into "default m" which I am going to post after the cpufreq git
     pull - as the two patches to make this work depend on a fix in Dave
     Jones's tree.

   - Function Level Reset (FLR) support in the Xen PCI backend.

  Fixes:

   - Kconfig dependencies for Xen PV keyboard and video
   - Compile warnings and constify fixes
   - Change over to use percpu_xxx instead of this_cpu_xxx"

Fix up trivial conflicts in drivers/tty/hvc/hvc_xen.c due to changes to
a removed commit.

* tag 'stable/for-linus-3.4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen:
  xen kconfig: relax INPUT_XEN_KBDDEV_FRONTEND deps
  xen/acpi-processor: C and P-state driver that uploads said data to hypervisor.
  xen: constify all instances of "struct attribute_group"
  xen/xenbus: ignore console/0
  hvc_xen: introduce HVC_XEN_FRONTEND
  hvc_xen: implement multiconsole support
  hvc_xen: support PV on HVM consoles
  xenbus: don't free other end details too early
  xen/enlighten: Expose MWAIT and MWAIT_LEAF if hypervisor OKs it.
  xen/setup/pm/acpi: Remove the call to boot_option_idle_override.
  xenbus: address compiler warnings
  xen: use this_cpu_xxx replace percpu_xxx funcs
  xen/pciback: Support pci_reset_function, aka FLR or D3 support.
  pci: Introduce __pci_reset_function_locked to be used when holding device_lock.
  xen: Utilize the restore_msi_irqs hook.

1 files changed, 95 insertions, 4 deletions

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 4172af8ceeb3..b132ade26f77 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. */