From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759289Ab0JVT3T (ORCPT ); Fri, 22 Oct 2010 15:29:19 -0400 Received: from smtp-outbound-2.vmware.com ([65.115.85.73]:55382 "EHLO smtp-outbound-2.vmware.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759036Ab0JVT3Q (ORCPT ); Fri, 22 Oct 2010 15:29:16 -0400 Subject: [PATCH 2/2] x86, apic: Add apic timer calibration hook From: Alok Kataria Reply-To: akataria@vmware.com To: Thomas Gleixner Cc: "H. Peter Anvin" , Ingo Molnar , the arch/x86 maintainers , LKML Content-Type: text/plain Organization: VMware INC. Date: Fri, 22 Oct 2010 12:29:15 -0700 Message-Id: <1287775755.27008.59.camel@ank32.eng.vmware.com> Mime-Version: 1.0 X-Mailer: Evolution 2.12.3 (2.12.3-8.el5_2.3) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add apic timer calibration hook. From: Alok N Kataria Add a new function ptr calibrate_APIC_clock to x86_init_timers structure. On native this does the usual apic calibration and local apic timer initialization. On VMware's platform we override it with a routine which gets that information from the hypervisor and initializes the local apic timer accordingly. Signed-off-by: Alok N Kataria Index: linux-x86-tree.git/arch/x86/include/asm/apic.h =================================================================== --- linux-x86-tree.git.orig/arch/x86/include/asm/apic.h 2010-10-22 11:37:47.000000000 -0700 +++ linux-x86-tree.git/arch/x86/include/asm/apic.h 2010-10-22 12:04:58.000000000 -0700 @@ -17,6 +17,10 @@ #define ARCH_APICTIMER_STOPS_ON_C3 1 +/* Clock divisor */ +#define APIC_DIVISOR 16 +#define LAPIC_CAL_LOOPS (HZ/10) + /* * Debugging macros */ @@ -238,6 +242,8 @@ extern void setup_boot_APIC_clock(void); extern void setup_secondary_APIC_clock(void); extern int APIC_init_uniprocessor(void); extern void enable_NMI_through_LVT0(void); +extern int native_calibrate_APIC_clock(void); +extern int initialize_lapic_timer(long delta, unsigned int calibration_result); /* * On 32bit this is mach-xxx local Index: linux-x86-tree.git/arch/x86/include/asm/x86_init.h =================================================================== --- linux-x86-tree.git.orig/arch/x86/include/asm/x86_init.h 2010-10-22 11:37:47.000000000 -0700 +++ linux-x86-tree.git/arch/x86/include/asm/x86_init.h 2010-10-22 11:54:45.000000000 -0700 @@ -83,11 +83,14 @@ struct x86_init_paging { * boot cpu * @tsc_pre_init: platform function called before TSC init * @timer_init: initialize the platform timer (default PIT/HPET) + * @calibrate_APIC_clock: calibrate APIC clock freq (ticks per HZ) and + * initializes the local APIC timer. */ struct x86_init_timers { void (*setup_percpu_clockev)(void); void (*tsc_pre_init)(void); void (*timer_init)(void); + int (*calibrate_APIC_clock)(void); }; /** Index: linux-x86-tree.git/arch/x86/kernel/cpu/vmware.c =================================================================== --- linux-x86-tree.git.orig/arch/x86/kernel/cpu/vmware.c 2010-10-22 11:37:47.000000000 -0700 +++ linux-x86-tree.git/arch/x86/kernel/cpu/vmware.c 2010-10-22 11:55:27.000000000 -0700 @@ -26,6 +26,7 @@ #include #include #include +#include #define CPUID_VMWARE_INFO_LEAF 0x40000000 #define VMWARE_HYPERVISOR_MAGIC 0x564D5868 @@ -72,17 +73,40 @@ static unsigned long vmware_get_tsc_khz( return tsc_hz; } +static int __init vmware_calibrate_APIC_clock(void) +{ + unsigned int calibration_result; + uint32_t eax, ebx, ecx, edx; + int err; + long delta; + unsigned long flags; + + VMWARE_PORT(GETHZ, eax, ebx, ecx, edx); + BUG_ON(!ecx); + calibration_result = ecx / HZ; + + printk(KERN_INFO "APIC bus freq read from hypervisor\n"); + + delta = (calibration_result * LAPIC_CAL_LOOPS) / APIC_DIVISOR; + local_irq_save(flags); + err = initialize_lapic_timer(delta, calibration_result); + local_irq_restore(flags); + + return err; +} + static void __init vmware_platform_setup(void) { uint32_t eax, ebx, ecx, edx; VMWARE_PORT(GETHZ, eax, ebx, ecx, edx); - if (ebx != UINT_MAX) + if (ebx != UINT_MAX) { x86_platform.calibrate_tsc = vmware_get_tsc_khz; - else + x86_init.timers.calibrate_APIC_clock = vmware_calibrate_APIC_clock; + } else printk(KERN_WARNING - "Failed to get TSC freq from the hypervisor\n"); + "Failed to setup VMware hypervisor platform\n"); } /* Index: linux-x86-tree.git/arch/x86/kernel/x86_init.c =================================================================== --- linux-x86-tree.git.orig/arch/x86/kernel/x86_init.c 2010-10-22 11:37:47.000000000 -0700 +++ linux-x86-tree.git/arch/x86/kernel/x86_init.c 2010-10-22 11:53:27.000000000 -0700 @@ -68,6 +68,7 @@ struct x86_init_ops x86_init __initdata .setup_percpu_clockev = setup_boot_APIC_clock, .tsc_pre_init = x86_init_noop, .timer_init = hpet_time_init, + .calibrate_APIC_clock = native_calibrate_APIC_clock }, .iommu = { Index: linux-x86-tree.git/arch/x86/kernel/apic/apic.c =================================================================== --- linux-x86-tree.git.orig/arch/x86/kernel/apic/apic.c 2010-10-22 11:47:47.000000000 -0700 +++ linux-x86-tree.git/arch/x86/kernel/apic/apic.c 2010-10-22 11:58:30.000000000 -0700 @@ -327,13 +327,6 @@ int lapic_get_maxlvt(void) } /* - * Local APIC timer - */ - -/* Clock divisor */ -#define APIC_DIVISOR 16 - -/* * This function sets up the local APIC timer, with a timeout of * 'clocks' APIC bus clock. During calibration we actually call * this function twice on the boot CPU, once with a bogus timeout @@ -550,8 +543,6 @@ static void __cpuinit setup_APIC_timer(v * back to normal later in the boot process). */ -#define LAPIC_CAL_LOOPS (HZ/10) - static __initdata int lapic_cal_loops = -1; static __initdata long lapic_cal_t1, lapic_cal_t2; static __initdata unsigned long long lapic_cal_tsc1, lapic_cal_tsc2; @@ -677,7 +668,7 @@ int __init initialize_lapic_timer(long d } /* Calibrates the APIC clock and initializes the local APIC timer */ -static int __init calibrate_APIC_clock(void) +int __init native_calibrate_APIC_clock(void) { struct clock_event_device *levt = &__get_cpu_var(lapic_events); void (*real_handler)(struct clock_event_device *dev); @@ -802,7 +793,7 @@ void __init setup_boot_APIC_clock(void) apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n" "calibrating APIC timer ...\n"); - if (calibrate_APIC_clock()) { + if (x86_init.timers.calibrate_APIC_clock()) { /* No broadcast on UP ! */ if (num_possible_cpus() > 1) setup_APIC_timer();