Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261795AbTHTIPA (ORCPT ); Wed, 20 Aug 2003 04:15:00 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261785AbTHTIOr (ORCPT ); Wed, 20 Aug 2003 04:14:47 -0400 Received: from twilight.ucw.cz ([81.30.235.3]:44209 "EHLO twilight.ucw.cz") by vger.kernel.org with ESMTP id S261826AbTHTIK0 (ORCPT ); Wed, 20 Aug 2003 04:10:26 -0400 Date: Wed, 20 Aug 2003 10:05:13 +0200 From: Vojtech Pavlik To: "Pallipadi, Venkatesh" Cc: Vojtech Pavlik , linux-kernel@vger.kernel.org, torvalds@osdl.org, "Nakajima, Jun" , "Mallick, Asit K" Subject: Re: [PATCH][2.6][2/5]Support for HPET based timer Message-ID: <20030820080513.GB17793@ucw.cz> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.4i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 16470 Lines: 514 On Tue, Aug 19, 2003 at 05:18:50PM -0700, Pallipadi, Venkatesh wrote: > Fixmap is for HPET memory map address access. As the timer > initialization happen > early in the boot sequence (before vm initialization), we need to have > fixmap() > and fix_to_virt() to access HPET memory map address. Ahh, yes, you're right. You can't use ioremap at that time. Actually I did the same on x86_64 not only because of vsyscalls. > Yes. Most of the code is generic, and can run on other platforms. The > only reason > I have that check is because, I haven't got chance to test this patch on > other > platforms. > > Thanks, > -Venkatesh > > > -----Original Message----- > > From: Vojtech Pavlik [mailto:vojtech@suse.cz] > > Sent: Tuesday, August 19, 2003 3:39 PM > > To: Pallipadi, Venkatesh > > Cc: linux-kernel@vger.kernel.org; torvalds@osdl.org; > > Nakajima, Jun; Mallick, Asit K > > Subject: Re: [PATCH][2.6][2/5]Support for HPET based timer > > > > > > On Tue, Aug 19, 2003 at 12:20:02PM -0700, Pallipadi, Venkatesh wrote: > > > > > 2/5 - hpet2.patch - All the changes required to use HPET in place > > > of PIT as the kernel base-timer at IRQ 0. > > > > What are you using the fixmap() for? i386 doesn't have vsyscalls ... > > > > Why are you limiting the HPET vendor ID to Intel? This code will > > happily run on other vendor hardware as well ... > > > > > > > diff -purN linux-2.6.0-test1/arch/i386/kernel/apic.c > > linux-2.6.0-test1-hpet/arch/i386/kernel/apic.c > > > --- linux-2.6.0-test1/arch/i386/kernel/apic.c > > 2003-07-13 20:39:27.000000000 -0700 > > > +++ linux-2.6.0-test1-hpet/arch/i386/kernel/apic.c > > 2003-08-13 11:36:24.000000000 -0700 > > > @@ -34,6 +34,7 @@ > > > #include > > > #include > > > #include > > > +#include > > > > > > #include > > > > > > @@ -749,7 +750,8 @@ static unsigned int __init get_8254_time > > > return count; > > > } > > > > > > -void __init wait_8254_wraparound(void) > > > +/* next tick in 8254 can be caught by catching timer wraparound */ > > > +static void __init wait_8254_wraparound(void) > > > { > > > unsigned int curr_count, prev_count=~0; > > > int delta; > > > @@ -771,6 +773,12 @@ void __init wait_8254_wraparound(void) > > > } > > > > > > /* > > > + * Default initialization for 8254 timers. If we use other > > timers like HPET, > > > + * we override this later > > > + */ > > > +void (*wait_timer_tick)(void) = wait_8254_wraparound; > > > + > > > +/* > > > * 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 > > > @@ -811,7 +819,7 @@ static void setup_APIC_timer(unsigned in > > > /* > > > * Wait for IRQ0's slice: > > > */ > > > - wait_8254_wraparound(); > > > + wait_timer_tick(); > > > > > > __setup_APIC_LVTT(clocks); > > > > > > @@ -854,7 +862,7 @@ int __init calibrate_APIC_clock(void) > > > * (the current tick might have been already half done) > > > */ > > > > > > - wait_8254_wraparound(); > > > + wait_timer_tick(); > > > > > > /* > > > * We wrapped around just now. Let's start: > > > @@ -867,7 +875,7 @@ int __init calibrate_APIC_clock(void) > > > * Let's wait LOOPS wraprounds: > > > */ > > > for (i = 0; i < LOOPS; i++) > > > - wait_8254_wraparound(); > > > + wait_timer_tick(); > > > > > > tt2 = apic_read(APIC_TMCCT); > > > if (cpu_has_tsc) > > > diff -purN linux-2.6.0-test1/arch/i386/kernel/time.c > > linux-2.6.0-test1-hpet/arch/i386/kernel/time.c > > > --- linux-2.6.0-test1/arch/i386/kernel/time.c > > 2003-07-13 20:34:29.000000000 -0700 > > > +++ linux-2.6.0-test1-hpet/arch/i386/kernel/time.c > > 2003-08-18 12:36:25.000000000 -0700 > > > @@ -60,6 +60,8 @@ > > > #include > > > #include > > > > > > +#include > > > + > > > #include > > > > > > #include "io_ports.h" > > > @@ -298,6 +300,12 @@ void __init time_init(void) > > > xtime.tv_nsec = (INITIAL_JIFFIES % HZ) * (NSEC_PER_SEC / HZ); > > > wall_to_monotonic.tv_nsec = -xtime.tv_nsec; > > > > > > +#ifdef CONFIG_HPET_TIMER > > > + if (hpet_enable() >= 0) { > > > + printk("Using HPET for base-timer\n"); > > > + } > > > +#endif > > > + > > > cur_timer = select_timer(); > > > time_init_hook(); > > > } > > > diff -purN linux-2.6.0-test1/arch/i386/kernel/time_hpet.c > > linux-2.6.0-test1-hpet/arch/i386/kernel/time_hpet.c > > > --- linux-2.6.0-test1/arch/i386/kernel/time_hpet.c > > 1969-12-31 16:00:00.000000000 -0800 > > > +++ linux-2.6.0-test1-hpet/arch/i386/kernel/time_hpet.c > > 2003-08-18 20:22:06.000000000 -0700 > > > @@ -0,0 +1,153 @@ > > > +/* > > > + * linux/arch/i386/kernel/time_hpet.c > > > + * This code largely copied from arch/x86_64/kernel/time.c > > > + * See that file for credits. > > > + * > > > + * 2003-06-30 Venkatesh Pallipadi - Additional changes > > for HPET support > > > + */ > > > + > > > +#include > > > +#include > > > +#include > > > +#include > > > +#include > > > +#include > > > + > > > +#include > > > +#include > > > +#include > > > + > > > +#include > > > +#include > > > + > > > +#include > > > + > > > +unsigned long hpet_period; /* fsecs / HPET clock */ > > > +unsigned long hpet_tick; /* hpet clks count per tick */ > > > +unsigned long hpet_address; /* hpet memory map address */ > > > + > > > +static int use_hpet; /* can be used for > > runtime check of hpet */ > > > +static int boot_hpet_disable; /* boottime override > > for HPET timer */ > > > + > > > +#define FSEC_TO_USEC (1000000000UL) > > > + > > > +#ifdef CONFIG_X86_LOCAL_APIC > > > +/* > > > + * HPET counters dont wrap around on every tick. They just > > change the > > > + * comparator value and continue. Next tick can be caught > > by checking > > > + * for a change in the comparator value. Used in apic.c. > > > + */ > > > +void __init wait_hpet_tick(void) > > > +{ > > > + unsigned int start_cmp_val, end_cmp_val; > > > + > > > + start_cmp_val = hpet_readl(HPET_T0_CMP); > > > + do { > > > + end_cmp_val = hpet_readl(HPET_T0_CMP); > > > + } while (start_cmp_val == end_cmp_val); > > > +} > > > +#endif > > > + > > > +/* > > > + * Check whether HPET was found by ACPI boot parse. If yes > > setup HPET > > > + * counter 0 for kernel base timer. > > > + */ > > > +int __init hpet_enable(void) > > > +{ > > > + unsigned int cfg, id; > > > + unsigned long tick_fsec_low, tick_fsec_high; /* tick in > > femto sec */ > > > + unsigned long hpet_tick_rem; > > > + > > > + if (boot_hpet_disable) > > > + return -1; > > > + > > > + if (!hpet_address) { > > > + return -1; > > > + } > > > + set_fixmap_nocache(FIX_HPET_BASE, hpet_address); > > > + printk(KERN_INFO "HPET enabled at %#lx\n", hpet_address); > > > + > > > + /* > > > + * Read the period, compute tick and quotient. > > > + */ > > > + id = hpet_readl(HPET_ID); > > > + > > > + /* > > > + * We are checking for value '1' or more in number field. > > > + * So, we are OK with HPET_EMULATE_RTC part too, where we need > > > + * to have atleast 2 timers. > > > + */ > > > + if (!(id & HPET_ID_NUMBER) || > > > + !(id & HPET_ID_LEGSUP)) > > > + return -1; > > > + > > > + if (((id & HPET_ID_VENDOR) >> HPET_ID_VENDOR_SHIFT) != > > > + HPET_ID_VENDOR_8086) > > > + return -1; > > > + > > > + hpet_period = hpet_readl(HPET_PERIOD); > > > + if ((hpet_period < HPET_MIN_PERIOD) || (hpet_period > > > HPET_MAX_PERIOD)) > > > + return -1; > > > + > > > + /* > > > + * 64 bit math > > > + * First changing tick into fsec > > > + * Then 64 bit div to find number of hpet clk per tick > > > + */ > > > + ASM_MUL64_REG(tick_fsec_low, tick_fsec_high, > > > + KERNEL_TICK_USEC, FSEC_TO_USEC); > > > + ASM_DIV64_REG(hpet_tick, hpet_tick_rem, > > > + hpet_period, tick_fsec_low, tick_fsec_high); > > > + > > > + if (hpet_tick_rem > (hpet_period >> 1)) > > > + hpet_tick++; /* rounding the result */ > > > + > > > + /* > > > + * Stop the timers and reset the main counter. > > > + */ > > > + cfg = hpet_readl(HPET_CFG); > > > + cfg &= ~HPET_CFG_ENABLE; > > > + hpet_writel(cfg, HPET_CFG); > > > + hpet_writel(0, HPET_COUNTER); > > > + hpet_writel(0, HPET_COUNTER + 4); > > > + > > > + /* > > > + * Set up timer 0, as periodic with first interrupt to > > happen at > > > + * hpet_tick, and period also hpet_tick. > > > + */ > > > + cfg = hpet_readl(HPET_T0_CFG); > > > + cfg |= HPET_TN_ENABLE | HPET_TN_PERIODIC | > > > + HPET_TN_SETVAL | HPET_TN_32BIT; > > > + hpet_writel(cfg, HPET_T0_CFG); > > > + hpet_writel(hpet_tick, HPET_T0_CMP); > > > + > > > + /* > > > + * Go! > > > + */ > > > + cfg = hpet_readl(HPET_CFG); > > > + cfg |= HPET_CFG_ENABLE | HPET_CFG_LEGACY; > > > + hpet_writel(cfg, HPET_CFG); > > > + > > > + use_hpet = 1; > > > +#ifdef CONFIG_X86_LOCAL_APIC > > > + wait_timer_tick = wait_hpet_tick; > > > +#endif > > > + return 0; > > > +} > > > + > > > +int is_hpet_enabled(void) > > > +{ > > > + return use_hpet; > > > +} > > > + > > > +static int __init hpet_setup(char* str) > > > +{ > > > + if (str) { > > > + if (!strncmp("disable", str, 7)) > > > + boot_hpet_disable = 1; > > > + } > > > + return 1; > > > +} > > > + > > > +__setup("hpet=", hpet_setup); > > > + > > > diff -purN linux-2.6.0-test1/include/asm-i386/apic.h > > linux-2.6.0-test1-hpet/include/asm-i386/apic.h > > > --- linux-2.6.0-test1/include/asm-i386/apic.h > > 2003-07-13 20:38:53.000000000 -0700 > > > +++ linux-2.6.0-test1-hpet/include/asm-i386/apic.h > > 2003-08-13 11:34:37.000000000 -0700 > > > @@ -64,6 +64,8 @@ static inline void ack_APIC_irq(void) > > > apic_write_around(APIC_EOI, 0); > > > } > > > > > > +extern void (*wait_timer_tick)(void); > > > + > > > extern int get_maxlvt(void); > > > extern void clear_local_APIC(void); > > > extern void connect_bsp_APIC (void); > > > diff -purN linux-2.6.0-test1/include/asm-i386/fixmap.h > > linux-2.6.0-test1-hpet/include/asm-i386/fixmap.h > > > --- linux-2.6.0-test1/include/asm-i386/fixmap.h > > 2003-07-13 20:29:30.000000000 -0700 > > > +++ linux-2.6.0-test1-hpet/include/asm-i386/fixmap.h > > 2003-08-14 13:10:31.000000000 -0700 > > > @@ -44,6 +44,9 @@ > > > enum fixed_addresses { > > > FIX_HOLE, > > > FIX_VSYSCALL, > > > +#ifdef CONFIG_HPET_TIMER > > > + FIX_HPET_BASE, > > > +#endif > > > #ifdef CONFIG_X86_LOCAL_APIC > > > FIX_APIC_BASE, /* local (CPU) APIC) -- required for > > SMP or not */ > > > #endif > > > diff -purN linux-2.6.0-test1/include/asm-i386/hpet.h > > linux-2.6.0-test1-hpet/include/asm-i386/hpet.h > > > --- linux-2.6.0-test1/include/asm-i386/hpet.h > > 1969-12-31 16:00:00.000000000 -0800 > > > +++ linux-2.6.0-test1-hpet/include/asm-i386/hpet.h > > 2003-08-18 20:22:40.000000000 -0700 > > > @@ -0,0 +1,104 @@ > > > + > > > +#ifndef _I386_HPET_H > > > +#define _I386_HPET_H > > > + > > > +#ifdef CONFIG_HPET_TIMER > > > + > > > +#include > > > +#include > > > +#include > > > +#include > > > +#include > > > +#include > > > +#include > > > +#include > > > +#include > > > +#include > > > +#include > > > +#include > > > + > > > +#include > > > +#include > > > +#include > > > +#include > > > +#include > > > +#include > > > +#include > > > +#include > > > + > > > +#include > > > +#include > > > + > > > +#include > > > + > > > +/* > > > + * Documentation on HPET can be found at: > > > + * http://www.intel.com/ial/home/sp/pcmmspec.htm > > > + * ftp://download.intel.com/ial/home/sp/mmts098.pdf > > > + */ > > > + > > > +#define HPET_ID 0x000 > > > +#define HPET_PERIOD 0x004 > > > +#define HPET_CFG 0x010 > > > +#define HPET_STATUS 0x020 > > > +#define HPET_COUNTER 0x0f0 > > > +#define HPET_T0_CFG 0x100 > > > +#define HPET_T0_CMP 0x108 > > > +#define HPET_T0_ROUTE 0x110 > > > +#define HPET_T1_CFG 0x120 > > > +#define HPET_T1_CMP 0x128 > > > +#define HPET_T1_ROUTE 0x130 > > > +#define HPET_T2_CFG 0x140 > > > +#define HPET_T2_CMP 0x148 > > > +#define HPET_T2_ROUTE 0x150 > > > + > > > +#define HPET_ID_VENDOR 0xffff0000 > > > +#define HPET_ID_LEGSUP 0x00008000 > > > +#define HPET_ID_NUMBER 0x00001f00 > > > +#define HPET_ID_REV 0x000000ff > > > + > > > +#define HPET_ID_VENDOR_SHIFT 16 > > > +#define HPET_ID_VENDOR_8086 0x8086 > > > + > > > +#define HPET_CFG_ENABLE 0x001 > > > +#define HPET_CFG_LEGACY 0x002 > > > + > > > +#define HPET_TN_ENABLE 0x004 > > > +#define HPET_TN_PERIODIC 0x008 > > > +#define HPET_TN_PERIODIC_CAP 0x010 > > > +#define HPET_TN_SETVAL 0x040 > > > +#define HPET_TN_32BIT 0x100 > > > + > > > +/* Use our own asm for 64 bit multiply/divide */ > > > +#define ASM_MUL64_REG(eax_out,edx_out,reg_in,eax_in) > > \ > > > + __asm__ __volatile__("mull %2" > > \ > > > + :"=a" (eax_out), "=d" (edx_out) > > \ > > > + :"r" (reg_in), "0" (eax_in)) > > > + > > > +#define > > ASM_DIV64_REG(eax_out,edx_out,reg_in,eax_in,edx_in) \ > > > + __asm__ __volatile__("divl %2" > > \ > > > + :"=a" (eax_out), "=d" (edx_out) > > \ > > > + :"r" (reg_in), "0" (eax_in), > > "1" (edx_in)) > > > + > > > +#define hpet_readl(a) > > readl(fix_to_virt(FIX_HPET_BASE) + a) > > > +#define hpet_writel(d,a) writel(d, > > fix_to_virt(FIX_HPET_BASE) + a) > > > + > > > +#define KERNEL_TICK_USEC (1000000UL/HZ) /* tick value > > in microsec */ > > > +/* Max HPET Period is 10^8 femto sec as in HPET spec */ > > > +#define HPET_MAX_PERIOD (100000000UL) > > > +/* > > > + * Min HPET period is 10^5 femto sec just for safety. If > > it is less than this, > > > + * then 32 bit HPET counter wrapsaround in less than 0.5 sec. > > > + */ > > > +#define HPET_MIN_PERIOD (100000UL) > > > + > > > +extern unsigned long hpet_period; /* fsecs / HPET clock */ > > > +extern unsigned long hpet_tick; /* hpet clks count per tick */ > > > +extern unsigned long hpet_address; /* hpet memory map address */ > > > +extern unsigned long hpet_virt_address; /* hpet kernel > > virtual address */ > > > + > > > +extern int hpet_enable(void); > > > +extern int is_hpet_enabled(void); > > > + > > > +#endif /* CONFIG_HPET_TIMER */ > > > +#endif /* _I386_HPET_H */ > > > diff -purN linux-2.6.0-test1/include/asm-i386/mc146818rtc.h > > linux-2.6.0-test1-hpet/include/asm-i386/mc146818rtc.h > > > --- linux-2.6.0-test1/include/asm-i386/mc146818rtc.h > > 2003-07-13 20:36:37.000000000 -0700 > > > +++ linux-2.6.0-test1-hpet/include/asm-i386/mc146818rtc.h > > 2003-08-18 20:23:43.000000000 -0700 > > > @@ -24,6 +24,10 @@ outb_p((addr),RTC_PORT(0)); \ > > > outb_p((val),RTC_PORT(1)); \ > > > }) > > > > > > +#ifdef CONFIG_HPET_TIMER > > > +#define RTC_IRQ 0 > > > +#else > > > #define RTC_IRQ 8 > > > +#endif > > > > > > #endif /* _ASM_MC146818RTC_H */ > > > diff -purN > > linux-2.6.0-test1/Documentation/kernel-parameters.txt > > linux-2.6.0-test1-hpet/Documentation/kernel-parameters.txt > > > --- linux-2.6.0-test1/Documentation/kernel-parameters.txt > > 2003-07-13 20:39:36.000000000 -0700 > > > +++ > > linux-2.6.0-test1-hpet/Documentation/kernel-parameters.txt > > 2003-08-18 20:37:41.000000000 -0700 > > > @@ -212,7 +212,10 @@ running once the system is up. > > > when calculating gettimeofday(). If > > specicified timesource > > > is not avalible, it defaults to PIT. > > > Format: { pit | tsc | cyclone | ... } > > > - > > > + > > > + hpet= [IA-32,HPET] option to disable HPET and use PIT. > > > + Format: disable > > > + > > > cm206= [HW,CD] > > > Format: { auto | [,][] } > > > > > > > > > > > > > > > > > -- > > Vojtech Pavlik > > SuSE Labs, SuSE CR > > > -- Vojtech Pavlik SuSE Labs, SuSE CR - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/