Drivers: hv: vmbus: Consolidate all Hyper-V specific clocksource code

As part of the effort to separate out architecture specific code,
consolidate all Hyper-V specific clocksource code to an architecture
specific code.

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

diff --git a/arch/x86/hyperv/hv_init.c b/arch/x86/hyperv/hv_init.c
index b5c8e04deacbc3ba9d753e88c4b614baa5fdff53..860233af4568d040025183e5a0bfc05f4554b919 100644 (file)
--- a/arch/x86/hyperv/hv_init.c
+++ b/arch/x86/hyperv/hv_init.c
@@ -24,6 +24,79 @@
 #include <linux/version.h>
 #include <linux/vmalloc.h>
 #include <linux/mm.h>
+#include <linux/clockchips.h>
+
+
+#ifdef CONFIG_X86_64
+
+static struct ms_hyperv_tsc_page *tsc_pg;
+
+static u64 read_hv_clock_tsc(struct clocksource *arg)
+{
+       u64 current_tick;
+
+       if (tsc_pg->tsc_sequence != 0) {
+               /*
+                * Use the tsc page to compute the value.
+                */
+
+               while (1) {
+                       u64 tmp;
+                       u32 sequence = tsc_pg->tsc_sequence;
+                       u64 cur_tsc;
+                       u64 scale = tsc_pg->tsc_scale;
+                       s64 offset = tsc_pg->tsc_offset;
+
+                       rdtscll(cur_tsc);
+                       /* current_tick = ((cur_tsc *scale) >> 64) + offset */
+                       asm("mulq %3"
+                               : "=d" (current_tick), "=a" (tmp)
+                               : "a" (cur_tsc), "r" (scale));
+
+                       current_tick += offset;
+                       if (tsc_pg->tsc_sequence == sequence)
+                               return current_tick;
+
+                       if (tsc_pg->tsc_sequence != 0)
+                               continue;
+                       /*
+                        * Fallback using MSR method.
+                        */
+                       break;
+               }
+       }
+       rdmsrl(HV_X64_MSR_TIME_REF_COUNT, current_tick);
+       return current_tick;
+}
+
+static struct clocksource hyperv_cs_tsc = {
+               .name           = "hyperv_clocksource_tsc_page",
+               .rating         = 400,
+               .read           = read_hv_clock_tsc,
+               .mask           = CLOCKSOURCE_MASK(64),
+               .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+#endif
+
+static u64 read_hv_clock_msr(struct clocksource *arg)
+{
+       u64 current_tick;
+       /*
+        * Read the partition counter to get the current tick count. This count
+        * is set to 0 when the partition is created and is incremented in
+        * 100 nanosecond units.
+        */
+       rdmsrl(HV_X64_MSR_TIME_REF_COUNT, current_tick);
+       return current_tick;
+}
+
+static struct clocksource hyperv_cs_msr = {
+       .name           = "hyperv_clocksource_msr",
+       .rating         = 400,
+       .read           = read_hv_clock_msr,
+       .mask           = CLOCKSOURCE_MASK(64),
+       .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
+};
 
 static void *hypercall_pg;
 /*
@@ -31,6 +104,7 @@ static void *hypercall_pg;
  * hypervisor has been detected.
  *
  * 1. Setup the hypercall page.
+ * 2. Register Hyper-V specific clocksource.
  */
 void hyperv_init(void)
 {
@@ -58,6 +132,37 @@ void hyperv_init(void)
        hypercall_msr.enable = 1;
        hypercall_msr.guest_physical_address = vmalloc_to_pfn(hypercall_pg);
        wrmsrl(HV_X64_MSR_HYPERCALL, hypercall_msr.as_uint64);
+
+       /*
+        * Register Hyper-V specific clocksource.
+        */
+#ifdef CONFIG_X86_64
+       if (ms_hyperv.features & HV_X64_MSR_REFERENCE_TSC_AVAILABLE) {
+               union hv_x64_msr_hypercall_contents tsc_msr;
+
+               tsc_pg = __vmalloc(PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL);
+               if (!tsc_pg) {
+                       clocksource_register_hz(&hyperv_cs_msr, NSEC_PER_SEC/100);
+                       return;
+               }
+
+               rdmsrl(HV_X64_MSR_REFERENCE_TSC, tsc_msr.as_uint64);
+
+               tsc_msr.enable = 1;
+               tsc_msr.guest_physical_address = vmalloc_to_pfn(tsc_pg);
+
+               wrmsrl(HV_X64_MSR_REFERENCE_TSC, tsc_msr.as_uint64);
+               clocksource_register_hz(&hyperv_cs_tsc, NSEC_PER_SEC/100);
+               return;
+       }
+#endif
+       /*
+        * For 32 bit guests just use the MSR based mechanism for reading
+        * the partition counter.
+        */
+
+       if (ms_hyperv.features & HV_X64_MSR_TIME_REF_COUNT_AVAILABLE)
+               clocksource_register_hz(&hyperv_cs_msr, NSEC_PER_SEC/100);
 }
 
 /*

diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h
index ed8e07399071dcd956ad3f2378130d70f9baeb1a..adfe8cc9f7e362e9ca490c924910da51e185eb71 100644 (file)
--- a/arch/x86/include/asm/mshyperv.h
+++ b/arch/x86/include/asm/mshyperv.h
@@ -25,6 +25,18 @@ union hv_x64_msr_hypercall_contents {
        };
 };
 
+/*
+ * TSC page layout.
+ */
+
+struct ms_hyperv_tsc_page {
+       volatile u32 tsc_sequence;
+       u32 reserved1;
+       volatile u64 tsc_scale;
+       volatile s64 tsc_offset;
+       u64 reserved2[509];
+};
+
 /*
  * The guest OS needs to register the guest ID with the hypervisor.
  * The guest ID is a 64 bit entity and the structure of this ID is

diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c
index c5a1e9ba9ae07b34830906d62b938ee3a69d1ed6..d3705a44971cdda178269134320fe28651b16abd 100644 (file)
--- a/arch/x86/kernel/cpu/mshyperv.c
+++ b/arch/x86/kernel/cpu/mshyperv.c
@@ -133,26 +133,6 @@ static uint32_t  __init ms_hyperv_platform(void)
        return 0;
 }
 
-static u64 read_hv_clock(struct clocksource *arg)
-{
-       u64 current_tick;
-       /*
-        * Read the partition counter to get the current tick count. This count
-        * is set to 0 when the partition is created and is incremented in
-        * 100 nanosecond units.
-        */
-       rdmsrl(HV_X64_MSR_TIME_REF_COUNT, current_tick);
-       return current_tick;
-}
-
-static struct clocksource hyperv_cs = {
-       .name           = "hyperv_clocksource",
-       .rating         = 400, /* use this when running on Hyperv*/
-       .read           = read_hv_clock,
-       .mask           = CLOCKSOURCE_MASK(64),
-       .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
-};
-
 static unsigned char hv_get_nmi_reason(void)
 {
        return 0;
@@ -208,9 +188,6 @@ static void __init ms_hyperv_init_platform(void)
                             "hv_nmi_unknown");
 #endif
 
-       if (ms_hyperv.features & HV_X64_MSR_TIME_REF_COUNT_AVAILABLE)
-               clocksource_register_hz(&hyperv_cs, NSEC_PER_SEC/100);
-
 #ifdef CONFIG_X86_IO_APIC
        no_timer_check = 1;
 #endif

diff --git a/drivers/hv/hv.c b/drivers/hv/hv.c
index fd3b9b98a29d181a7d309cb3594d9fed312a2b99..1a33b59776d3fa3a1a428e659ca7dde36e1597b6 100644 (file)
--- a/drivers/hv/hv.c
+++ b/drivers/hv/hv.c
@@ -87,56 +87,6 @@ static int query_hypervisor_info(void)
        return max_leaf;
 }
 
-#ifdef CONFIG_X86_64
-static u64 read_hv_clock_tsc(struct clocksource *arg)
-{
-       u64 current_tick;
-       struct ms_hyperv_tsc_page *tsc_pg = hv_context.tsc_page;
-
-       if (tsc_pg->tsc_sequence != 0) {
-               /*
-                * Use the tsc page to compute the value.
-                */
-
-               while (1) {
-                       u64 tmp;
-                       u32 sequence = tsc_pg->tsc_sequence;
-                       u64 cur_tsc;
-                       u64 scale = tsc_pg->tsc_scale;
-                       s64 offset = tsc_pg->tsc_offset;
-
-                       rdtscll(cur_tsc);
-                       /* current_tick = ((cur_tsc *scale) >> 64) + offset */
-                       asm("mulq %3"
-                               : "=d" (current_tick), "=a" (tmp)
-                               : "a" (cur_tsc), "r" (scale));
-
-                       current_tick += offset;
-                       if (tsc_pg->tsc_sequence == sequence)
-                               return current_tick;
-
-                       if (tsc_pg->tsc_sequence != 0)
-                               continue;
-                       /*
-                        * Fallback using MSR method.
-                        */
-                       break;
-               }
-       }
-       rdmsrl(HV_X64_MSR_TIME_REF_COUNT, current_tick);
-       return current_tick;
-}
-
-static struct clocksource hyperv_cs_tsc = {
-               .name           = "hyperv_clocksource_tsc_page",
-               .rating         = 425,
-               .read           = read_hv_clock_tsc,
-               .mask           = CLOCKSOURCE_MASK(64),
-               .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
-};
-#endif
-
-
 /*
  * hv_init - Main initialization routine.
  *
@@ -171,29 +121,7 @@ int hv_init(void)
        if (!hypercall_msr.enable)
                return -ENOTSUPP;
 
-#ifdef CONFIG_X86_64
-       if (ms_hyperv.features & HV_X64_MSR_REFERENCE_TSC_AVAILABLE) {
-               union hv_x64_msr_hypercall_contents tsc_msr;
-               void *va_tsc;
-
-               va_tsc = __vmalloc(PAGE_SIZE, GFP_KERNEL, PAGE_KERNEL);
-               if (!va_tsc)
-                       goto cleanup;
-               hv_context.tsc_page = va_tsc;
-
-               rdmsrl(HV_X64_MSR_REFERENCE_TSC, tsc_msr.as_uint64);
-
-               tsc_msr.enable = 1;
-               tsc_msr.guest_physical_address = vmalloc_to_pfn(va_tsc);
-
-               wrmsrl(HV_X64_MSR_REFERENCE_TSC, tsc_msr.as_uint64);
-               clocksource_register_hz(&hyperv_cs_tsc, NSEC_PER_SEC/100);
-       }
-#endif
        return 0;
-
-cleanup:
-       return -ENOTSUPP;
 }
 
 /*
@@ -204,29 +132,6 @@ cleanup:
 void hv_cleanup(bool crash)
 {
 
-#ifdef CONFIG_X86_64
-       union hv_x64_msr_hypercall_contents hypercall_msr;
-       /*
-        * Cleanup the TSC page based CS.
-        */
-       if (ms_hyperv.features & HV_X64_MSR_REFERENCE_TSC_AVAILABLE) {
-               /*
-                * Crash can happen in an interrupt context and unregistering
-                * a clocksource is impossible and redundant in this case.
-                */
-               if (!oops_in_progress) {
-                       clocksource_change_rating(&hyperv_cs_tsc, 10);
-                       clocksource_unregister(&hyperv_cs_tsc);
-               }
-
-               hypercall_msr.as_uint64 = 0;
-               wrmsrl(HV_X64_MSR_REFERENCE_TSC, hypercall_msr.as_uint64);
-               if (!crash) {
-                       vfree(hv_context.tsc_page);
-                       hv_context.tsc_page = NULL;
-               }
-       }
-#endif
 }
 
 /*

diff --git a/drivers/hv/hyperv_vmbus.h b/drivers/hv/hyperv_vmbus.h
index 09485269d537753dbf889cc2d72d5804e868af3e..947455d307071efe49bb76e63df54ce46ab6f81d 100644 (file)
--- a/drivers/hv/hyperv_vmbus.h
+++ b/drivers/hv/hyperv_vmbus.h
@@ -416,14 +416,6 @@ struct hv_context {
 
 extern struct hv_context hv_context;
 
-struct ms_hyperv_tsc_page {
-       volatile u32 tsc_sequence;
-       u32 reserved1;
-       volatile u64 tsc_scale;
-       volatile s64 tsc_offset;
-       u64 reserved2[509];
-};
-
 struct hv_ring_buffer_debug_info {
        u32 current_interrupt_mask;
        u32 current_read_index;