Drivers: hv vmbus: Move Hypercall page setup out of common code

As part of the effort to separate out architecture specific code, move the
hypercall page setup to an architecture specific file.

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

5 files changed, 78 insertions, 0 deletions

diff --git a/arch/x86/Kbuild b/arch/x86/Kbuild
index eb3abf8ac44e..586b786b3edf 100644
--- a/arch/x86/Kbuild
+++ b/arch/x86/Kbuild
@@ -7,6 +7,9 @@ obj-$(CONFIG_KVM) += kvm/
 # Xen paravirtualization support
 obj-$(CONFIG_XEN) += xen/
 
+# Hyper-V paravirtualization support
+obj-$(CONFIG_HYPERVISOR_GUEST) += hyperv/
+
 # lguest paravirtualization support
 obj-$(CONFIG_LGUEST_GUEST) += lguest/
 
diff --git a/arch/x86/hyperv/Makefile b/arch/x86/hyperv/Makefile
new file mode 100644
index 000000000000..171ae09864d7
--- /dev/null
+++ b/arch/x86/hyperv/Makefile
@@ -0,0 +1 @@
+obj-y		:= hv_init.o
diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
new file mode 100644
index 000000000000..3206bfda586d
--- /dev/null
+++ b/arch/x86/hyperv/hv_init.c
@@ -0,0 +1,62 @@
+/*
+ * X86 specific Hyper-V initialization code.
+ *
+ * Copyright (C) 2016, Microsoft, Inc.
+ *
+ * Author : K. Y. Srinivasan <kys@microsoft.com>
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published
+ * by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT.  See the GNU General Public License for more
+ * details.
+ *
+ */
+
+#include <linux/types.h>
+#include <asm/hypervisor.h>
+#include <asm/hyperv.h>
+#include <asm/mshyperv.h>
+#include <linux/version.h>
+#include <linux/vmalloc.h>
+#include <linux/mm.h>
+
+void *hv_hypercall_pg;
+/*
+ * This function is to be invoked early in the boot sequence after the
+ * hypervisor has been detected.
+ *
+ * 1. Setup the hypercall page.
+ */
+void hyperv_init(void)
+{
+	u64 guest_id;
+	union hv_x64_msr_hypercall_contents hypercall_msr;
+
+	if (x86_hyper != &x86_hyper_ms_hyperv)
+		return;
+
+	/*
+	 * Setup the hypercall page and enable hypercalls.
+	 * 1. Register the guest ID
+	 * 2. Enable the hypercall and register the hypercall page
+	 */
+	guest_id = generate_guest_id(0, LINUX_VERSION_CODE, 0);
+	wrmsrl(HV_X64_MSR_GUEST_OS_ID, guest_id);
+
+	hv_hypercall_pg  = __vmalloc(PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL_EXEC);
+	if (hv_hypercall_pg == NULL) {
+		wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
+		return;
+	}
+
+	rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
+	hypercall_msr.enable = 1;
+	hypercall_msr.guest_physical_address = vmalloc_to_pfn(hv_hypercall_pg);
+	wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
+}
+EXPORT_SYMBOL_GPL(hv_hypercall_pg);
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index 15a0c275c82e..e5f57e15a507 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -80,4 +80,9 @@ void hv_setup_kexec_handler(void (*handler)(void));
 void hv_remove_kexec_handler(void);
 void hv_setup_crash_handler(void (*handler)(struct pt_regs *regs));
 void hv_remove_crash_handler(void);
+
+#if IS_ENABLED(CONFIG_HYPERV)
+void hyperv_init(void);
+extern void *hv_hypercall_pg;
+#endif
 #endif
diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index 65e20c97e04b..c5a1e9ba9ae0 100644
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -227,6 +227,13 @@ static void __init ms_hyperv_init_platform(void)
 	 */
 	if (efi_enabled(EFI_BOOT))
 		x86_platform.get_nmi_reason = hv_get_nmi_reason;
+
+#if IS_ENABLED(CONFIG_HYPERV)
+	/*
+	 * Setup the hook to get control post apic initialization.
+	 */
+	x86_platform.apic_post_init = hyperv_init;
+#endif
 }
 
 const __refconst struct hypervisor_x86 x86_hyper_ms_hyperv = {