[PATCH 04/18] Drivers: hv: vmbus: Move Hypercall invocation code out of common code

[kys@exchange.microsoft.com]

From: K. Y. Srinivasan <kys@microsoft.com>

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

Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
---
 arch/x86/hyperv/hv_init.c       |   54 +++++++++++++++++++++++++++++++++++---
 arch/x86/include/asm/mshyperv.h |    1 -
 drivers/hv/hv.c                 |   52 -------------------------------------
 drivers/hv/hyperv_vmbus.h       |    1 -
 4 files changed, 49 insertions(+), 59 deletions(-)

diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index 3206bfda..b5c8e04 100644
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -25,7 +25,7 @@
 #include <linux/vmalloc.h>
 #include <linux/mm.h>
 
-void *hv_hypercall_pg;
+static void *hypercall_pg;
 /*
  * This function is to be invoked early in the boot sequence after the
  * hypervisor has been detected.
@@ -48,15 +48,59 @@ void hyperv_init(void)
 	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) {
+	hypercall_pg  = __vmalloc(PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL_EXEC);
+	if (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);
+	hypercall_msr.guest_physical_address = vmalloc_to_pfn(hypercall_pg);
 	wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
 }
-EXPORT_SYMBOL_GPL(hv_hypercall_pg);
+
+/*
+ * hv_do_hypercall- Invoke the specified hypercall
+ */
+u64 hv_do_hypercall(u64 control, void *input, void *output)
+{
+	u64 input_address = (input) ? virt_to_phys(input) : 0;
+	u64 output_address = (output) ? virt_to_phys(output) : 0;
+#ifdef CONFIG_X86_64
+	u64 hv_status = 0;
+
+	if (!hypercall_pg)
+		return (u64)ULLONG_MAX;
+
+	__asm__ __volatile__("mov %0, %%r8" : : "r" (output_address) : "r8");
+	__asm__ __volatile__("call *%3" : "=a" (hv_status) :
+			     "c" (control), "d" (input_address),
+			     "m" (hypercall_pg));
+
+	return hv_status;
+
+#else
+
+	u32 control_hi = control >> 32;
+	u32 control_lo = control & 0xFFFFFFFF;
+	u32 hv_status_hi = 1;
+	u32 hv_status_lo = 1;
+	u32 input_address_hi = input_address >> 32;
+	u32 input_address_lo = input_address & 0xFFFFFFFF;
+	u32 output_address_hi = output_address >> 32;
+	u32 output_address_lo = output_address & 0xFFFFFFFF;
+
+	if (!hypercall_pg)
+		return (u64)ULLONG_MAX;
+
+	__asm__ __volatile__ ("call *%8" : "=d"(hv_status_hi),
+			      "=a"(hv_status_lo) : "d" (control_hi),
+			      "a" (control_lo), "b" (input_address_hi),
+			      "c" (input_address_lo), "D"(output_address_hi),
+			      "S"(output_address_lo), "m" (hypercall_pg));
+
+	return hv_status_lo | ((u64)hv_status_hi << 32);
+#endif /* !x86_64 */
+}
+EXPORT_SYMBOL_GPL(hv_do_hypercall);
diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index e5f57e1..ed8e073 100644
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -83,6 +83,5 @@ static inline  __u64 generate_guest_id(__u64 d_info1, __u64 kernel_version,
 
 #if IS_ENABLED(CONFIG_HYPERV)
 void hyperv_init(void);
-extern void *hv_hypercall_pg;
 #endif
 #endif
diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index a11e827..11388d3 100644
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -36,7 +36,6 @@
 /* The one and only */
 struct hv_context hv_context = {
 	.synic_initialized	= false,
-	.hypercall_page		= NULL,
 };
 
 #define HV_TIMER_FREQUENCY (10 * 1000 * 1000) /* 100ns period */
@@ -88,52 +87,6 @@ static int query_hypervisor_info(void)
 	return max_leaf;
 }
 
-/*
- * hv_do_hypercall- Invoke the specified hypercall
- */
-u64 hv_do_hypercall(u64 control, void *input, void *output)
-{
-	u64 input_address = (input) ? virt_to_phys(input) : 0;
-	u64 output_address = (output) ? virt_to_phys(output) : 0;
-	void *hypercall_page = hv_context.hypercall_page;
-#ifdef CONFIG_X86_64
-	u64 hv_status = 0;
-
-	if (!hypercall_page)
-		return (u64)ULLONG_MAX;
-
-	__asm__ __volatile__("mov %0, %%r8" : : "r" (output_address) : "r8");
-	__asm__ __volatile__("call *%3" : "=a" (hv_status) :
-			     "c" (control), "d" (input_address),
-			     "m" (hypercall_page));
-
-	return hv_status;
-
-#else
-
-	u32 control_hi = control >> 32;
-	u32 control_lo = control & 0xFFFFFFFF;
-	u32 hv_status_hi = 1;
-	u32 hv_status_lo = 1;
-	u32 input_address_hi = input_address >> 32;
-	u32 input_address_lo = input_address & 0xFFFFFFFF;
-	u32 output_address_hi = output_address >> 32;
-	u32 output_address_lo = output_address & 0xFFFFFFFF;
-
-	if (!hypercall_page)
-		return (u64)ULLONG_MAX;
-
-	__asm__ __volatile__ ("call *%8" : "=d"(hv_status_hi),
-			      "=a"(hv_status_lo) : "d" (control_hi),
-			      "a" (control_lo), "b" (input_address_hi),
-			      "c" (input_address_lo), "D"(output_address_hi),
-			      "S"(output_address_lo), "m" (hypercall_page));
-
-	return hv_status_lo | ((u64)hv_status_hi << 32);
-#endif /* !x86_64 */
-}
-EXPORT_SYMBOL_GPL(hv_do_hypercall);
-
 #ifdef CONFIG_X86_64
 static cycle_t read_hv_clock_tsc(struct clocksource *arg)
 {
@@ -218,8 +171,6 @@ int hv_init(void)
 	if (!hypercall_msr.enable)
 		return -ENOTSUPP;
 
-	hv_context.hypercall_page = hv_hypercall_pg;
-
 #ifdef CONFIG_X86_64
 	if (ms_hyperv.features & HV_X64_MSR_REFERENCE_TSC_AVAILABLE) {
 		union hv_x64_msr_hypercall_contents tsc_msr;
@@ -466,9 +417,6 @@ int hv_synic_init(unsigned int cpu)
 	union hv_synic_scontrol sctrl;
 	u64 vp_index;
 
-	if (!hv_context.hypercall_page)
-		return -EFAULT;
-
 	/* Check the version */
 	rdmsrl(HV_X64_MSR_SVERSION, version);
 
diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index da57626..0948526 100644
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -371,7 +371,6 @@ struct hv_context {
 	*/
 	u64 guestid;
 
-	void *hypercall_page;
 	void *tsc_page;
 
 	bool synic_initialized;
-- 
1.7.4.1