[PATCH 30/41] Drivers: hv: Move Hyper-V misc functionality to arch-neutral code

[Tim Gardner]

From: Michael Kelley <mikelley at microsoft.com>

BugLink: https://bugs.launchpad.net/bugs/1949770

The check for whether hibernation is possible, and the enabling of
Hyper-V panic notification during kexec, are both architecture neutral.
Move the code from under arch/x86 and into drivers/hv/hv_common.c where
it can also be used for ARM64.

No functional change.

Signed-off-by: Michael Kelley <mikelley at microsoft.com>
Link: https://lore.kernel.org/r/1626287687-2045-4-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu at kernel.org>
(backported from commit 6dc77fa5ac2cf26f846a51492dbe42526e26d0f2)
Signed-off-by: Tim Gardner <tim.gardner at canonical.com>
[rtg - minor context differences, dropped hv_is_hibernation_supported() from
arch/arm64/hyperv/mshyperv.c]
---
 arch/arm64/hyperv/mshyperv.c   |  6 ------
 arch/x86/hyperv/hv_init.c      |  7 +------
 arch/x86/kernel/cpu/mshyperv.c | 10 ----------
 drivers/hv/hv_common.c         | 17 +++++++++++++++++
 4 files changed, 18 insertions(+), 22 deletions(-)

diff --git a/arch/arm64/hyperv/mshyperv.c b/arch/arm64/hyperv/mshyperv.c
index 1748f99ca65b..1b365fd8f481 100644
--- a/arch/arm64/hyperv/mshyperv.c
+++ b/arch/arm64/hyperv/mshyperv.c
@@ -146,12 +146,6 @@ bool hv_is_hyperv_initialized(void)
 }
 EXPORT_SYMBOL_GPL(hv_is_hyperv_initialized);
 
-bool hv_is_hibernation_supported(void)
-{
-	return false;
-}
-EXPORT_SYMBOL_GPL(hv_is_hibernation_supported);
-
 bool hv_is_isolation_supported(void)
 {
 	return false;
diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index 4924d8c03228..34892c078b19 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -7,9 +7,9 @@
  * Author : K. Y. Srinivasan <kys at microsoft.com>
  */
 
-#include <linux/acpi.h>
 #include <linux/efi.h>
 #include <linux/types.h>
+#include <linux/io.h>
 #include <asm/apic.h>
 #include <asm/desc.h>
 #include <asm/hypervisor.h>
@@ -465,8 +465,3 @@ bool hv_is_hyperv_initialized(void)
 }
 EXPORT_SYMBOL_GPL(hv_is_hyperv_initialized);
 
-bool hv_is_hibernation_supported(void)
-{
-	return acpi_sleep_state_supported(ACPI_STATE_S4);
-}
-EXPORT_SYMBOL_GPL(hv_is_hibernation_supported);
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 44891430ea1c..f4c6fc790494 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -286,16 +286,6 @@ static void __init ms_hyperv_init_platform(void)
 			cpuid_eax(HYPERV_CPUID_NESTED_FEATURES);
 	}
 
-	/*
-	 * Hyper-V expects to get crash register data or kmsg when
-	 * crash enlightment is available and system crashes. Set
-	 * crash_kexec_post_notifiers to be true to make sure that
-	 * calling crash enlightment interface before running kdump
-	 * kernel.
-	 */
-	if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE)
-		crash_kexec_post_notifiers = true;
-
 #ifdef CONFIG_X86_LOCAL_APIC
 	if (ms_hyperv.features & HV_ACCESS_FREQUENCY_MSRS &&
 	    ms_hyperv.misc_features & HV_FEATURE_FREQUENCY_MSRS_AVAILABLE) {
diff --git a/drivers/hv/hv_common.c b/drivers/hv/hv_common.c
index 8caffed7261a..01b88b8d42fe 100644
--- a/drivers/hv/hv_common.c
+++ b/drivers/hv/hv_common.c
@@ -13,6 +13,7 @@
  */
 
 #include <linux/types.h>
+#include <linux/acpi.h>
 #include <linux/export.h>
 #include <linux/bitfield.h>
 #include <linux/cpumask.h>
@@ -70,6 +71,16 @@ int __init hv_common_init(void)
 {
 	int i;
 
+	/*
+	 * Hyper-V expects to get crash register data or kmsg when
+	 * crash enlightment is available and system crashes. Set
+	 * crash_kexec_post_notifiers to be true to make sure that
+	 * calling crash enlightment interface before running kdump
+	 * kernel.
+	 */
+	if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE)
+		crash_kexec_post_notifiers = true;
+
 	/*
 	 * Allocate the per-CPU state for the hypercall input arg.
 	 * If this allocation fails, we will not be able to setup
@@ -218,6 +229,12 @@ static u64 __hv_read_ref_counter(void)
 u64 (*hv_read_reference_counter)(void) = __hv_read_ref_counter;
 EXPORT_SYMBOL_GPL(hv_read_reference_counter);
 
+bool hv_is_hibernation_supported(void)
+{
+	return !hv_root_partition && acpi_sleep_state_supported(ACPI_STATE_S4);
+}
+EXPORT_SYMBOL_GPL(hv_is_hibernation_supported);
+
 /* These __weak functions provide default "no-op" behavior and
  * may be overridden by architecture specific versions. Architectures
  * for which the default "no-op" behavior is sufficient can leave
-- 
2.33.1