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authorKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2012-02-13 22:26:32 -0500
committerKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2012-03-10 12:44:44 -0500
commit73c154c60be106b47f15d1111fc2d75cc7a436f2 (patch)
treeaf32a6e0fd49bfafa1499cd1a8cdf15caae27054 /arch/ia64/include
parentcc7335b2f6acc0f24c7fac80ce536301f7d52214 (diff)
xen/enlighten: Expose MWAIT and MWAIT_LEAF if hypervisor OKs it.
For the hypervisor to take advantage of the MWAIT support it needs to extract from the ACPI _CST the register address. But the hypervisor does not have the support to parse DSDT so it relies on the initial domain (dom0) to parse the ACPI Power Management information and push it up to the hypervisor. The pushing of the data is done by the processor_harveset_xen module which parses the information that the ACPI parser has graciously exposed in 'struct acpi_processor'. For the ACPI parser to also expose the Cx states for MWAIT, we need to expose the MWAIT capability (leaf 1). Furthermore we also need to expose the MWAIT_LEAF capability (leaf 5) for cstate.c to properly function. The hypervisor could expose these flags when it traps the XEN_EMULATE_PREFIX operations, but it can't do it since it needs to be backwards compatible. Instead we choose to use the native CPUID to figure out if the MWAIT capability exists and use the XEN_SET_PDC query hypercall to figure out if the hypervisor wants us to expose the MWAIT_LEAF capability or not. Note: The XEN_SET_PDC query was implemented in c/s 23783: "ACPI: add _PDC input override mechanism". With this in place, instead of C3 ACPI IOPORT 415 we get now C3:ACPI FFH INTEL MWAIT 0x20 Note: The cpu_idle which would be calling the mwait variants for idling never gets set b/c we set the default pm_idle to be the hypercall variant. Acked-by: Jan Beulich <JBeulich@suse.com> [v2: Fix missing header file include and #ifdef] Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'arch/ia64/include')
-rw-r--r--arch/ia64/include/asm/xen/interface.h1
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/ia64/include/asm/xen/interface.h b/arch/ia64/include/asm/xen/interface.h
index fbb519828aa..09d5f7fd9db 100644
--- a/arch/ia64/include/asm/xen/interface.h
+++ b/arch/ia64/include/asm/xen/interface.h
@@ -77,6 +77,7 @@ DEFINE_GUEST_HANDLE(int);
DEFINE_GUEST_HANDLE(long);
DEFINE_GUEST_HANDLE(void);
DEFINE_GUEST_HANDLE(uint64_t);
+DEFINE_GUEST_HANDLE(uint32_t);
typedef unsigned long xen_pfn_t;
DEFINE_GUEST_HANDLE(xen_pfn_t);