[PATCH] i386: vMI timer patches

VMI timer code.  It works by taking over the local APIC clock when APIC is
configured, which requires a couple hooks into the APIC code.  The backend
timer code could be commonized into the timer infrastructure, but there are
some pieces missing (stolen time, in particular), and the exact semantics of
when to do accounting for NO_IDLE need to be shared between different
hypervisors as well.  So for now, VMI timer is a separate module.

[Adrian Bunk: cleanups]

Subject: VMI timer patches
Signed-off-by: Zachary Amsden <zach@vmware.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Cc: Andi Kleen <ak@suse.de>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>

1 files changed, 45 insertions, 0 deletions

diff --git a/arch/i386/kernel/vmi.c b/arch/i386/kernel/vmi.c
index a94d64b10f7..bb5a7abf949 100644
--- a/arch/i386/kernel/vmi.c
+++ b/arch/i386/kernel/vmi.c
@@ -34,6 +34,7 @@
 #include <asm/apic.h>
 #include <asm/processor.h>
 #include <asm/timer.h>
+#include <asm/vmi_time.h>
 
 /* Convenient for calling VMI functions indirectly in the ROM */
 typedef u32 __attribute__((regparm(1))) (VROMFUNC)(void);
@@ -67,6 +68,7 @@ struct {
 	void (*set_linear_mapping)(int, u32, u32, u32);
 	void (*flush_tlb)(int);
 	void (*set_initial_ap_state)(int, int);
+	void (*halt)(void);
 } vmi_ops;
 
 /* XXX move this to alternative.h */
@@ -252,6 +254,19 @@ static void vmi_nop(void)
 {
 }
 
+/* For NO_IDLE_HZ, we stop the clock when halting the kernel */
+#ifdef CONFIG_NO_IDLE_HZ
+static fastcall void vmi_safe_halt(void)
+{
+	int idle = vmi_stop_hz_timer();
+	vmi_ops.halt();
+	if (idle) {
+		local_irq_disable();
+		vmi_account_time_restart_hz_timer();
+		local_irq_enable();
+	}
+}
+#endif
 
 #ifdef CONFIG_DEBUG_PAGE_TYPE
 
@@ -727,7 +742,12 @@ static inline int __init activate_vmi(void)
 		     (char *)paravirt_ops.save_fl);
 	patch_offset(&irq_save_disable_callout[IRQ_PATCH_DISABLE],
 		     (char *)paravirt_ops.irq_disable);
+#ifndef CONFIG_NO_IDLE_HZ
 	para_fill(safe_halt, Halt);
+#else
+	vmi_ops.halt = vmi_get_function(VMI_CALL_Halt);
+	paravirt_ops.safe_halt = vmi_safe_halt;
+#endif
 	para_fill(wbinvd, WBINVD);
 	/* paravirt_ops.read_msr = vmi_rdmsr */
 	/* paravirt_ops.write_msr = vmi_wrmsr */
@@ -838,6 +858,31 @@ static inline int __init activate_vmi(void)
 #endif
 
 	/*
+	 * Check for VMI timer functionality by probing for a cycle frequency method
+	 */
+	reloc = call_vrom_long_func(vmi_rom, get_reloc, VMI_CALL_GetCycleFrequency);
+	if (rel->type != VMI_RELOCATION_NONE) {
+		vmi_timer_ops.get_cycle_frequency = (void *)rel->eip;
+		vmi_timer_ops.get_cycle_counter =
+			vmi_get_function(VMI_CALL_GetCycleCounter);
+		vmi_timer_ops.get_wallclock =
+			vmi_get_function(VMI_CALL_GetWallclockTime);
+		vmi_timer_ops.wallclock_updated =
+			vmi_get_function(VMI_CALL_WallclockUpdated);
+		vmi_timer_ops.set_alarm = vmi_get_function(VMI_CALL_SetAlarm);
+		vmi_timer_ops.cancel_alarm =
+			 vmi_get_function(VMI_CALL_CancelAlarm);
+		paravirt_ops.time_init = vmi_time_init;
+		paravirt_ops.get_wallclock = vmi_get_wallclock;
+		paravirt_ops.set_wallclock = vmi_set_wallclock;
+#ifdef CONFIG_X86_LOCAL_APIC
+		paravirt_ops.setup_boot_clock = vmi_timer_setup_boot_alarm;
+		paravirt_ops.setup_secondary_clock = vmi_timer_setup_secondary_alarm;
+#endif
+		custom_sched_clock = vmi_sched_clock;
+	}
+
+	/*
 	 * Alternative instruction rewriting doesn't happen soon enough
 	 * to convert VMI_IRET to a call instead of a jump; so we have
 	 * to do this before IRQs get reenabled.  Fortunately, it is