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>

7 files changed, 82 insertions, 42 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index c36976d3bd1a..be8de24fd6dd 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5962,6 +5962,7 @@ S:	Maintained
 F:      arch/x86/include/asm/mshyperv.h
 F:      arch/x86/include/uapi/asm/hyperv.h
 F:      arch/x86/kernel/cpu/mshyperv.c
+F:      arch/x86/hyperv
 F:      drivers/hid/hid-hyperv.c
 F:      drivers/hv/
 F:      drivers/input/serio/hyperv-keyboard.c
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 = {
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index 714e1ebc834c..d8d41542d93c 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -193,7 +193,6 @@ int hv_init(void)
 {
         int max_leaf;
         union hv_x64_msr_hypercall_contents hypercall_msr;
-        void *virtaddr = NULL;
 
         memset(hv_context.synic_event_page, 0, sizeof(void *) * NR_CPUS);
         memset(hv_context.synic_message_page, 0,
@@ -211,33 +210,15 @@ int hv_init(void)
 
         max_leaf = query_hypervisor_info();
 
-        /*
-         * Write our OS ID.
-         */
-        hv_context.guestid = generate_guest_id(0, LINUX_VERSION_CODE, 0);
-        wrmsrl(HV_X64_MSR_GUEST_OS_ID, hv_context.guestid);
 
         /* See if the hypercall page is already set */
-        rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
-
-        virtaddr = __vmalloc(PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL_EXEC);
-
-        if (!virtaddr)
-                goto cleanup;
-
-        hypercall_msr.enable = 1;
-
-        hypercall_msr.guest_physical_address = vmalloc_to_pfn(virtaddr);
-        wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
-
-        /* Confirm that hypercall page did get setup. */
         hypercall_msr.as_uint64 = 0;
         rdmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 
         if (!hypercall_msr.enable)
-                goto cleanup;
+                return -ENOTSUPP;
 
-        hv_context.hypercall_page = virtaddr;
+        hv_context.hypercall_page = hv_hypercall_pg;
 
 #ifdef CONFIG_X86_64
         if (ms_hyperv.features & HV_X64_MSR_REFERENCE_TSC_AVAILABLE) {
@@ -261,15 +242,6 @@ int hv_init(void)
         return 0;
 
 cleanup:
-        if (virtaddr) {
-                if (hypercall_msr.enable) {
-                        hypercall_msr.as_uint64 = 0;
-                        wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
-                }
-
-                vfree(virtaddr);
-        }
-
         return -ENOTSUPP;
 }
 
@@ -280,20 +252,9 @@ cleanup:
  */
 void hv_cleanup(bool crash)
 {
-        union hv_x64_msr_hypercall_contents hypercall_msr;
-
-        /* Reset our OS id */
-        wrmsrl(HV_X64_MSR_GUEST_OS_ID, 0);
-
-        if (hv_context.hypercall_page) {
-                hypercall_msr.as_uint64 = 0;
-                wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
-                if (!crash)
-                        vfree(hv_context.hypercall_page);
-                hv_context.hypercall_page = NULL;
-        }
 
 #ifdef CONFIG_X86_64
+        union hv_x64_msr_hypercall_contents hypercall_msr;
         /*
          * Cleanup the TSC page based CS.
          */