diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 854744bde2240298a1a44ecebe5fa506b8da80aa..5fbe07706ae9eedae14c1582004a0fc52e4daa40 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -1154,6 +1154,8 @@ and is between 256 and 4096 characters. It is defined in the file nointroute [IA-64] + nojitter [IA64] Disables jitter checking for ITC timers. + nolapic [IA-32,APIC] Do not enable or use the local APIC. nolapic_timer [IA-32,APIC] Do not use the local APIC timer. diff --git a/Documentation/time_interpolators.txt b/Documentation/time_interpolators.txt deleted file mode 100644 index e3b60854fbc28910fef5f1b7dd862098444a57d0..0000000000000000000000000000000000000000 --- a/Documentation/time_interpolators.txt +++ /dev/null @@ -1,41 +0,0 @@ -Time Interpolators ------------------- - -Time interpolators are a base of time calculation between timer ticks and -allow an accurate determination of time down to the accuracy of the time -source in nanoseconds. - -The architecture specific code typically provides gettimeofday and -settimeofday under Linux. The time interpolator provides both if an arch -defines CONFIG_TIME_INTERPOLATION. The arch still must set up timer tick -operations and call the necessary functions to advance the clock. - -With the time interpolator a standardized interface exists for time -interpolation between ticks. The provided logic is highly scalable -and has been tested in SMP situations of up to 512 CPUs. - -If CONFIG_TIME_INTERPOLATION is defined then the architecture specific code -(or the device drivers - like HPET) may register time interpolators. -These are typically defined in the following way: - -static struct time_interpolator my_interpolator { - .frequency = MY_FREQUENCY, - .source = TIME_SOURCE_MMIO32, - .shift = 8, /* scaling for higher accuracy */ - .drift = -1, /* Unknown drift */ - .jitter = 0 /* time source is stable */ -}; - -void time_init(void) -{ - .... - /* Initialization of the timer *. - my_interpolator.address = &my_timer; - register_time_interpolator(&my_interpolator); - .... -} - -For more details see include/linux/timex.h and kernel/timer.c. - -Christoph Lameter , October 31, 2004 - diff --git a/arch/ia64/Kconfig b/arch/ia64/Kconfig index 616c96e734831e4b508009d5b3473b0cff31eb6e..36c7b9682aa6f923a6e47ad364512dcf890f64c7 100644 --- a/arch/ia64/Kconfig +++ b/arch/ia64/Kconfig @@ -62,7 +62,11 @@ config GENERIC_CALIBRATE_DELAY bool default y -config TIME_INTERPOLATION +config GENERIC_TIME + bool + default y + +config GENERIC_TIME_VSYSCALL bool default y diff --git a/arch/ia64/configs/bigsur_defconfig b/arch/ia64/configs/bigsur_defconfig index 90e9c2e61bf467d0378b31def6792eb7bfe0082e..9eb48c0927b007baa1d14af8d139df35590ff2c7 100644 --- a/arch/ia64/configs/bigsur_defconfig +++ b/arch/ia64/configs/bigsur_defconfig @@ -85,7 +85,7 @@ CONFIG_MMU=y CONFIG_SWIOTLB=y CONFIG_RWSEM_XCHGADD_ALGORITHM=y CONFIG_GENERIC_CALIBRATE_DELAY=y -CONFIG_TIME_INTERPOLATION=y +CONFIG_GENERIC_TIME=y CONFIG_EFI=y CONFIG_GENERIC_IOMAP=y CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER=y diff --git a/arch/ia64/configs/gensparse_defconfig b/arch/ia64/configs/gensparse_defconfig index 0d29aa2066b309036f42d389d06411da4d9d36dd..3a9ed951db085a77940f7264ca7b2a74b5edab45 100644 --- a/arch/ia64/configs/gensparse_defconfig +++ b/arch/ia64/configs/gensparse_defconfig @@ -86,7 +86,7 @@ CONFIG_MMU=y CONFIG_SWIOTLB=y CONFIG_RWSEM_XCHGADD_ALGORITHM=y CONFIG_GENERIC_CALIBRATE_DELAY=y -CONFIG_TIME_INTERPOLATION=y +CONFIG_GENERIC_TIME=y CONFIG_EFI=y CONFIG_GENERIC_IOMAP=y CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER=y diff --git a/arch/ia64/configs/sim_defconfig b/arch/ia64/configs/sim_defconfig index d9146c31ea13bb5c8b3fead3f5f3a91087b1e7e4..c420d9f3df98ddccf0e4580e4c93636c36952d0c 100644 --- a/arch/ia64/configs/sim_defconfig +++ b/arch/ia64/configs/sim_defconfig @@ -86,7 +86,7 @@ CONFIG_MMU=y CONFIG_SWIOTLB=y CONFIG_RWSEM_XCHGADD_ALGORITHM=y CONFIG_GENERIC_CALIBRATE_DELAY=y -CONFIG_TIME_INTERPOLATION=y +CONFIG_GENERIC_TIME=y CONFIG_EFI=y CONFIG_GENERIC_IOMAP=y CONFIG_SCHED_NO_NO_OMIT_FRAME_POINTER=y diff --git a/arch/ia64/configs/sn2_defconfig b/arch/ia64/configs/sn2_defconfig index 64e951de4e5749b64ca721601f0bddfd4dd7a886..4c9ffc47bc7a3e53f87e00febd4af727109320b0 100644 --- a/arch/ia64/configs/sn2_defconfig +++ b/arch/ia64/configs/sn2_defconfig @@ -93,7 +93,7 @@ CONFIG_SWIOTLB=y CONFIG_RWSEM_XCHGADD_ALGORITHM=y CONFIG_GENERIC_FIND_NEXT_BIT=y CONFIG_GENERIC_CALIBRATE_DELAY=y -CONFIG_TIME_INTERPOLATION=y +CONFIG_GENERIC_TIME=y CONFIG_DMI=y CONFIG_EFI=y CONFIG_GENERIC_IOMAP=y diff --git a/arch/ia64/configs/tiger_defconfig b/arch/ia64/configs/tiger_defconfig index 205bbc30b0d07f48b3317b6ae950ca0a57e68072..3dbb3987df277cf11a43e4062b86111046c2350c 100644 --- a/arch/ia64/configs/tiger_defconfig +++ b/arch/ia64/configs/tiger_defconfig @@ -97,7 +97,7 @@ CONFIG_RWSEM_XCHGADD_ALGORITHM=y # CONFIG_ARCH_HAS_ILOG2_U64 is not set CONFIG_GENERIC_FIND_NEXT_BIT=y CONFIG_GENERIC_CALIBRATE_DELAY=y -CONFIG_TIME_INTERPOLATION=y +CONFIG_GENERIC_TIME=y CONFIG_DMI=y CONFIG_EFI=y CONFIG_GENERIC_IOMAP=y diff --git a/arch/ia64/configs/zx1_defconfig b/arch/ia64/configs/zx1_defconfig index 1c7955c163588110be1d8d70c584238aac4d7404..4a060fc39934e5bb30166eeb4fde9e15934e07dd 100644 --- a/arch/ia64/configs/zx1_defconfig +++ b/arch/ia64/configs/zx1_defconfig @@ -96,7 +96,7 @@ CONFIG_RWSEM_XCHGADD_ALGORITHM=y # CONFIG_ARCH_HAS_ILOG2_U64 is not set CONFIG_GENERIC_FIND_NEXT_BIT=y CONFIG_GENERIC_CALIBRATE_DELAY=y -CONFIG_TIME_INTERPOLATION=y +CONFIG_GENERIC_TIME=y CONFIG_DMI=y CONFIG_EFI=y CONFIG_GENERIC_IOMAP=y diff --git a/arch/ia64/defconfig b/arch/ia64/defconfig index 80298ef905ebc0e9b3210e61158ef5484759bee9..03172dc8c4031fb51e8e1a620617f330076d85e9 100644 --- a/arch/ia64/defconfig +++ b/arch/ia64/defconfig @@ -97,7 +97,7 @@ CONFIG_RWSEM_XCHGADD_ALGORITHM=y # CONFIG_ARCH_HAS_ILOG2_U64 is not set CONFIG_GENERIC_FIND_NEXT_BIT=y CONFIG_GENERIC_CALIBRATE_DELAY=y -CONFIG_TIME_INTERPOLATION=y +CONFIG_GENERIC_TIME=y CONFIG_DMI=y CONFIG_EFI=y CONFIG_GENERIC_IOMAP=y diff --git a/arch/ia64/kernel/asm-offsets.c b/arch/ia64/kernel/asm-offsets.c index 2236fabbb3c60fcf6453a8b07a1448b9cb09e6bd..0aebc6f79e95349ce2268b3031a968a1eafebf1f 100644 --- a/arch/ia64/kernel/asm-offsets.c +++ b/arch/ia64/kernel/asm-offsets.c @@ -7,6 +7,7 @@ #define ASM_OFFSETS_C 1 #include +#include #include #include @@ -15,6 +16,7 @@ #include #include "../kernel/sigframe.h" +#include "../kernel/fsyscall_gtod_data.h" #define DEFINE(sym, val) \ asm volatile("\n->" #sym " %0 " #val : : "i" (val)) @@ -256,17 +258,24 @@ void foo(void) BLANK(); /* used by fsys_gettimeofday in arch/ia64/kernel/fsys.S */ - DEFINE(IA64_TIME_INTERPOLATOR_ADDRESS_OFFSET, offsetof (struct time_interpolator, addr)); - DEFINE(IA64_TIME_INTERPOLATOR_SOURCE_OFFSET, offsetof (struct time_interpolator, source)); - DEFINE(IA64_TIME_INTERPOLATOR_SHIFT_OFFSET, offsetof (struct time_interpolator, shift)); - DEFINE(IA64_TIME_INTERPOLATOR_NSEC_OFFSET, offsetof (struct time_interpolator, nsec_per_cyc)); - DEFINE(IA64_TIME_INTERPOLATOR_OFFSET_OFFSET, offsetof (struct time_interpolator, offset)); - DEFINE(IA64_TIME_INTERPOLATOR_LAST_CYCLE_OFFSET, offsetof (struct time_interpolator, last_cycle)); - DEFINE(IA64_TIME_INTERPOLATOR_LAST_COUNTER_OFFSET, offsetof (struct time_interpolator, last_counter)); - DEFINE(IA64_TIME_INTERPOLATOR_JITTER_OFFSET, offsetof (struct time_interpolator, jitter)); - DEFINE(IA64_TIME_INTERPOLATOR_MASK_OFFSET, offsetof (struct time_interpolator, mask)); - DEFINE(IA64_TIME_SOURCE_CPU, TIME_SOURCE_CPU); - DEFINE(IA64_TIME_SOURCE_MMIO64, TIME_SOURCE_MMIO64); - DEFINE(IA64_TIME_SOURCE_MMIO32, TIME_SOURCE_MMIO32); - DEFINE(IA64_TIMESPEC_TV_NSEC_OFFSET, offsetof (struct timespec, tv_nsec)); + DEFINE(IA64_GTOD_LOCK_OFFSET, + offsetof (struct fsyscall_gtod_data_t, lock)); + DEFINE(IA64_GTOD_WALL_TIME_OFFSET, + offsetof (struct fsyscall_gtod_data_t, wall_time)); + DEFINE(IA64_GTOD_MONO_TIME_OFFSET, + offsetof (struct fsyscall_gtod_data_t, monotonic_time)); + DEFINE(IA64_CLKSRC_MASK_OFFSET, + offsetof (struct fsyscall_gtod_data_t, clk_mask)); + DEFINE(IA64_CLKSRC_MULT_OFFSET, + offsetof (struct fsyscall_gtod_data_t, clk_mult)); + DEFINE(IA64_CLKSRC_SHIFT_OFFSET, + offsetof (struct fsyscall_gtod_data_t, clk_shift)); + DEFINE(IA64_CLKSRC_MMIO_OFFSET, + offsetof (struct fsyscall_gtod_data_t, clk_fsys_mmio)); + DEFINE(IA64_CLKSRC_CYCLE_LAST_OFFSET, + offsetof (struct fsyscall_gtod_data_t, clk_cycle_last)); + DEFINE(IA64_ITC_JITTER_OFFSET, + offsetof (struct itc_jitter_data_t, itc_jitter)); + DEFINE(IA64_ITC_LASTCYCLE_OFFSET, + offsetof (struct itc_jitter_data_t, itc_lastcycle)); } diff --git a/arch/ia64/kernel/cyclone.c b/arch/ia64/kernel/cyclone.c index e00b21514f7c665e97e1374d41c323ef915c1d57..2fd96d9062a1359b41964c3b4e3d90c8879034a3 100644 --- a/arch/ia64/kernel/cyclone.c +++ b/arch/ia64/kernel/cyclone.c @@ -3,6 +3,7 @@ #include #include #include +#include #include /* IBM Summit (EXA) Cyclone counter code*/ @@ -18,13 +19,21 @@ void __init cyclone_setup(void) use_cyclone = 1; } +static void __iomem *cyclone_mc; -struct time_interpolator cyclone_interpolator = { - .source = TIME_SOURCE_MMIO64, - .shift = 16, - .frequency = CYCLONE_TIMER_FREQ, - .drift = -100, - .mask = (1LL << 40) - 1 +static cycle_t read_cyclone(void) +{ + return (cycle_t)readq((void __iomem *)cyclone_mc); +} + +static struct clocksource clocksource_cyclone = { + .name = "cyclone", + .rating = 300, + .read = read_cyclone, + .mask = (1LL << 40) - 1, + .mult = 0, /*to be caluclated*/ + .shift = 16, + .flags = CLOCK_SOURCE_IS_CONTINUOUS, }; int __init init_cyclone_clock(void) @@ -44,13 +53,15 @@ int __init init_cyclone_clock(void) offset = (CYCLONE_CBAR_ADDR); reg = (u64*)ioremap_nocache(offset, sizeof(u64)); if(!reg){ - printk(KERN_ERR "Summit chipset: Could not find valid CBAR register.\n"); + printk(KERN_ERR "Summit chipset: Could not find valid CBAR" + " register.\n"); use_cyclone = 0; return -ENODEV; } base = readq(reg); if(!base){ - printk(KERN_ERR "Summit chipset: Could not find valid CBAR value.\n"); + printk(KERN_ERR "Summit chipset: Could not find valid CBAR" + " value.\n"); use_cyclone = 0; return -ENODEV; } @@ -60,7 +71,8 @@ int __init init_cyclone_clock(void) offset = (base + CYCLONE_PMCC_OFFSET); reg = (u64*)ioremap_nocache(offset, sizeof(u64)); if(!reg){ - printk(KERN_ERR "Summit chipset: Could not find valid PMCC register.\n"); + printk(KERN_ERR "Summit chipset: Could not find valid PMCC" + " register.\n"); use_cyclone = 0; return -ENODEV; } @@ -71,7 +83,8 @@ int __init init_cyclone_clock(void) offset = (base + CYCLONE_MPCS_OFFSET); reg = (u64*)ioremap_nocache(offset, sizeof(u64)); if(!reg){ - printk(KERN_ERR "Summit chipset: Could not find valid MPCS register.\n"); + printk(KERN_ERR "Summit chipset: Could not find valid MPCS" + " register.\n"); use_cyclone = 0; return -ENODEV; } @@ -82,7 +95,8 @@ int __init init_cyclone_clock(void) offset = (base + CYCLONE_MPMC_OFFSET); cyclone_timer = (u32*)ioremap_nocache(offset, sizeof(u32)); if(!cyclone_timer){ - printk(KERN_ERR "Summit chipset: Could not find valid MPMC register.\n"); + printk(KERN_ERR "Summit chipset: Could not find valid MPMC" + " register.\n"); use_cyclone = 0; return -ENODEV; } @@ -93,7 +107,8 @@ int __init init_cyclone_clock(void) int stall = 100; while(stall--) barrier(); if(readl(cyclone_timer) == old){ - printk(KERN_ERR "Summit chipset: Counter not counting! DISABLED\n"); + printk(KERN_ERR "Summit chipset: Counter not counting!" + " DISABLED\n"); iounmap(cyclone_timer); cyclone_timer = 0; use_cyclone = 0; @@ -101,8 +116,11 @@ int __init init_cyclone_clock(void) } } /* initialize last tick */ - cyclone_interpolator.addr = cyclone_timer; - register_time_interpolator(&cyclone_interpolator); + cyclone_mc = cyclone_timer; + clocksource_cyclone.fsys_mmio = cyclone_timer; + clocksource_cyclone.mult = clocksource_hz2mult(CYCLONE_TIMER_FREQ, + clocksource_cyclone.shift); + clocksource_register(&clocksource_cyclone); return 0; } diff --git a/arch/ia64/kernel/fsys.S b/arch/ia64/kernel/fsys.S index 3f926c2dc708044542a0b34be94f42e0b58912f2..44841971f077bfd812bdc7da38638a6ef99784d5 100644 --- a/arch/ia64/kernel/fsys.S +++ b/arch/ia64/kernel/fsys.S @@ -147,12 +147,11 @@ ENTRY(fsys_set_tid_address) FSYS_RETURN END(fsys_set_tid_address) -/* - * Ensure that the time interpolator structure is compatible with the asm code - */ -#if IA64_TIME_INTERPOLATOR_SOURCE_OFFSET !=0 || IA64_TIME_INTERPOLATOR_SHIFT_OFFSET != 2 \ - || IA64_TIME_INTERPOLATOR_JITTER_OFFSET != 3 || IA64_TIME_INTERPOLATOR_NSEC_OFFSET != 4 -#error fsys_gettimeofday incompatible with changes to struct time_interpolator +#if IA64_GTOD_LOCK_OFFSET !=0 +#error fsys_gettimeofday incompatible with changes to struct fsyscall_gtod_data_t +#endif +#if IA64_ITC_JITTER_OFFSET !=0 +#error fsys_gettimeofday incompatible with changes to struct itc_jitter_data_t #endif #define CLOCK_REALTIME 0 #define CLOCK_MONOTONIC 1 @@ -179,126 +178,124 @@ ENTRY(fsys_gettimeofday) // r11 = preserved: saved ar.pfs // r12 = preserved: memory stack // r13 = preserved: thread pointer - // r14 = address of mask / mask + // r14 = address of mask / mask value // r15 = preserved: system call number // r16 = preserved: current task pointer - // r17 = wall to monotonic use - // r18 = time_interpolator->offset - // r19 = address of wall_to_monotonic - // r20 = pointer to struct time_interpolator / pointer to time_interpolator->address - // r21 = shift factor - // r22 = address of time interpolator->last_counter - // r23 = address of time_interpolator->last_cycle - // r24 = adress of time_interpolator->offset - // r25 = last_cycle value - // r26 = last_counter value - // r27 = pointer to xtime + // r17 = (not used) + // r18 = (not used) + // r19 = address of itc_lastcycle + // r20 = struct fsyscall_gtod_data (= address of gtod_lock.sequence) + // r21 = address of mmio_ptr + // r22 = address of wall_time or monotonic_time + // r23 = address of shift / value + // r24 = address mult factor / cycle_last value + // r25 = itc_lastcycle value + // r26 = address clocksource cycle_last + // r27 = (not used) // r28 = sequence number at the beginning of critcal section - // r29 = address of seqlock + // r29 = address of itc_jitter // r30 = time processing flags / memory address // r31 = pointer to result // Predicates // p6,p7 short term use // p8 = timesource ar.itc // p9 = timesource mmio64 - // p10 = timesource mmio32 + // p10 = timesource mmio32 - not used // p11 = timesource not to be handled by asm code - // p12 = memory time source ( = p9 | p10) - // p13 = do cmpxchg with time_interpolator_last_cycle + // p12 = memory time source ( = p9 | p10) - not used + // p13 = do cmpxchg with itc_lastcycle // p14 = Divide by 1000 // p15 = Add monotonic // - // Note that instructions are optimized for McKinley. McKinley can process two - // bundles simultaneously and therefore we continuously try to feed the CPU - // two bundles and then a stop. - tnat.nz p6,p0 = r31 // branch deferred since it does not fit into bundle structure + // Note that instructions are optimized for McKinley. McKinley can + // process two bundles simultaneously and therefore we continuously + // try to feed the CPU two bundles and then a stop. + // + // Additional note that code has changed a lot. Optimization is TBD. + // Comments begin with "?" are maybe outdated. + tnat.nz p6,p0 = r31 // ? branch deferred to fit later bundle mov pr = r30,0xc000 // Set predicates according to function add r2 = TI_FLAGS+IA64_TASK_SIZE,r16 - movl r20 = time_interpolator + movl r20 = fsyscall_gtod_data // load fsyscall gettimeofday data address ;; - ld8 r20 = [r20] // get pointer to time_interpolator structure - movl r29 = xtime_lock + movl r29 = itc_jitter_data // itc_jitter + add r22 = IA64_GTOD_WALL_TIME_OFFSET,r20 // wall_time ld4 r2 = [r2] // process work pending flags - movl r27 = xtime - ;; // only one bundle here - ld8 r21 = [r20] // first quad with control information + ;; +(p15) add r22 = IA64_GTOD_MONO_TIME_OFFSET,r20 // monotonic_time + add r21 = IA64_CLKSRC_MMIO_OFFSET,r20 + add r19 = IA64_ITC_LASTCYCLE_OFFSET,r29 and r2 = TIF_ALLWORK_MASK,r2 -(p6) br.cond.spnt.few .fail_einval // deferred branch +(p6) br.cond.spnt.few .fail_einval // ? deferred branch ;; - add r10 = IA64_TIME_INTERPOLATOR_ADDRESS_OFFSET,r20 - extr r3 = r21,32,32 // time_interpolator->nsec_per_cyc - extr r8 = r21,0,16 // time_interpolator->source + add r26 = IA64_CLKSRC_CYCLE_LAST_OFFSET,r20 // clksrc_cycle_last cmp.ne p6, p0 = 0, r2 // Fallback if work is scheduled (p6) br.cond.spnt.many fsys_fallback_syscall ;; - cmp.eq p8,p12 = 0,r8 // Check for cpu timer - cmp.eq p9,p0 = 1,r8 // MMIO64 ? - extr r2 = r21,24,8 // time_interpolator->jitter - cmp.eq p10,p0 = 2,r8 // MMIO32 ? - cmp.ltu p11,p0 = 2,r8 // function or other clock -(p11) br.cond.spnt.many fsys_fallback_syscall + // Begin critical section +.time_redo: + ld4.acq r28 = [r20] // gtod_lock.sequence, Must take first + ;; + and r28 = ~1,r28 // And make sequence even to force retry if odd ;; - setf.sig f7 = r3 // Setup for scaling of counter -(p15) movl r19 = wall_to_monotonic -(p12) ld8 r30 = [r10] - cmp.ne p13,p0 = r2,r0 // need jitter compensation? - extr r21 = r21,16,8 // shift factor + ld8 r30 = [r21] // clocksource->mmio_ptr + add r24 = IA64_CLKSRC_MULT_OFFSET,r20 + ld4 r2 = [r29] // itc_jitter value + add r23 = IA64_CLKSRC_SHIFT_OFFSET,r20 + add r14 = IA64_CLKSRC_MASK_OFFSET,r20 ;; -.time_redo: - .pred.rel.mutex p8,p9,p10 - ld4.acq r28 = [r29] // xtime_lock.sequence. Must come first for locking purposes + ld4 r3 = [r24] // clocksource mult value + ld8 r14 = [r14] // clocksource mask value + cmp.eq p8,p9 = 0,r30 // use cpu timer if no mmio_ptr ;; - and r28 = ~1,r28 // Make sequence even to force retry if odd + setf.sig f7 = r3 // Setup for mult scaling of counter +(p8) cmp.ne p13,p0 = r2,r0 // need itc_jitter compensation, set p13 + ld4 r23 = [r23] // clocksource shift value + ld8 r24 = [r26] // get clksrc_cycle_last value +(p9) cmp.eq p13,p0 = 0,r30 // if mmio_ptr, clear p13 jitter control ;; + .pred.rel.mutex p8,p9 (p8) mov r2 = ar.itc // CPU_TIMER. 36 clocks latency!!! - add r22 = IA64_TIME_INTERPOLATOR_LAST_COUNTER_OFFSET,r20 -(p9) ld8 r2 = [r30] // readq(ti->address). Could also have latency issues.. -(p10) ld4 r2 = [r30] // readw(ti->address) -(p13) add r23 = IA64_TIME_INTERPOLATOR_LAST_CYCLE_OFFSET,r20 - ;; // could be removed by moving the last add upward - ld8 r26 = [r22] // time_interpolator->last_counter -(p13) ld8 r25 = [r23] // time interpolator->last_cycle - add r24 = IA64_TIME_INTERPOLATOR_OFFSET_OFFSET,r20 -(p15) ld8 r17 = [r19],IA64_TIMESPEC_TV_NSEC_OFFSET - ld8 r9 = [r27],IA64_TIMESPEC_TV_NSEC_OFFSET - add r14 = IA64_TIME_INTERPOLATOR_MASK_OFFSET, r20 - ;; - ld8 r18 = [r24] // time_interpolator->offset - ld8 r8 = [r27],-IA64_TIMESPEC_TV_NSEC_OFFSET // xtime.tv_nsec -(p13) sub r3 = r25,r2 // Diff needed before comparison (thanks davidm) - ;; - ld8 r14 = [r14] // time_interpolator->mask -(p13) cmp.gt.unc p6,p7 = r3,r0 // check if it is less than last. p6,p7 cleared - sub r10 = r2,r26 // current_counter - last_counter - ;; -(p6) sub r10 = r25,r26 // time we got was less than last_cycle +(p9) ld8 r2 = [r30] // MMIO_TIMER. Could also have latency issues.. +(p13) ld8 r25 = [r19] // get itc_lastcycle value + ;; // ? could be removed by moving the last add upward + ld8 r9 = [r22],IA64_TIMESPEC_TV_NSEC_OFFSET // tv_sec + ;; + ld8 r8 = [r22],-IA64_TIMESPEC_TV_NSEC_OFFSET // tv_nsec +(p13) sub r3 = r25,r2 // Diff needed before comparison (thanks davidm) + ;; +(p13) cmp.gt.unc p6,p7 = r3,r0 // check if it is less than last. p6,p7 cleared + sub r10 = r2,r24 // current_cycle - last_cycle + ;; +(p6) sub r10 = r25,r24 // time we got was less than last_cycle (p7) mov ar.ccv = r25 // more than last_cycle. Prep for cmpxchg ;; +(p7) cmpxchg8.rel r3 = [r19],r2,ar.ccv + ;; +(p7) cmp.ne p7,p0 = r25,r3 // if cmpxchg not successful + ;; +(p7) sub r10 = r3,r24 // then use new last_cycle instead + ;; and r10 = r10,r14 // Apply mask ;; setf.sig f8 = r10 nop.i 123 ;; -(p7) cmpxchg8.rel r3 = [r23],r2,ar.ccv -EX(.fail_efault, probe.w.fault r31, 3) // This takes 5 cycles and we have spare time + // fault check takes 5 cycles and we have spare time +EX(.fail_efault, probe.w.fault r31, 3) xmpy.l f8 = f8,f7 // nsec_per_cyc*(counter-last_counter) -(p15) add r9 = r9,r17 // Add wall to monotonic.secs to result secs ;; -(p15) ld8 r17 = [r19],-IA64_TIMESPEC_TV_NSEC_OFFSET -(p7) cmp.ne p7,p0 = r25,r3 // if cmpxchg not successful redo - // simulate tbit.nz.or p7,p0 = r28,0 + // ? simulate tbit.nz.or p7,p0 = r28,0 getf.sig r2 = f8 mf - add r8 = r8,r18 // Add time interpolator offset ;; - ld4 r10 = [r29] // xtime_lock.sequence -(p15) add r8 = r8, r17 // Add monotonic.nsecs to nsecs - shr.u r2 = r2,r21 - ;; // overloaded 3 bundles! - // End critical section. + ld4 r10 = [r20] // gtod_lock.sequence + shr.u r2 = r2,r23 // shift by factor + ;; // ? overloaded 3 bundles! add r8 = r8,r2 // Add xtime.nsecs - cmp4.ne.or p7,p0 = r28,r10 -(p7) br.cond.dpnt.few .time_redo // sequence number changed ? + cmp4.ne p7,p0 = r28,r10 +(p7) br.cond.dpnt.few .time_redo // sequence number changed, redo + // End critical section. // Now r8=tv->tv_nsec and r9=tv->tv_sec mov r10 = r0 movl r2 = 1000000000 @@ -308,19 +305,19 @@ EX(.fail_efault, probe.w.fault r31, 3) // This takes 5 cycles and we have spare .time_normalize: mov r21 = r8 cmp.ge p6,p0 = r8,r2 -(p14) shr.u r20 = r8, 3 // We can repeat this if necessary just wasting some time +(p14) shr.u r20 = r8, 3 // We can repeat this if necessary just wasting time ;; (p14) setf.sig f8 = r20 (p6) sub r8 = r8,r2 -(p6) add r9 = 1,r9 // two nops before the branch. -(p14) setf.sig f7 = r3 // Chances for repeats are 1 in 10000 for gettod +(p6) add r9 = 1,r9 // two nops before the branch. +(p14) setf.sig f7 = r3 // Chances for repeats are 1 in 10000 for gettod (p6) br.cond.dpnt.few .time_normalize ;; // Divided by 8 though shift. Now divide by 125 // The compiler was able to do that with a multiply // and a shift and we do the same -EX(.fail_efault, probe.w.fault r23, 3) // This also costs 5 cycles -(p14) xmpy.hu f8 = f8, f7 // xmpy has 5 cycles latency so use it... +EX(.fail_efault, probe.w.fault r23, 3) // This also costs 5 cycles +(p14) xmpy.hu f8 = f8, f7 // xmpy has 5 cycles latency so use it ;; mov r8 = r0 (p14) getf.sig r2 = f8 diff --git a/arch/ia64/kernel/fsyscall_gtod_data.h b/arch/ia64/kernel/fsyscall_gtod_data.h new file mode 100644 index 0000000000000000000000000000000000000000..490dab55fba34ea730f9d002858394ab24dd28a0 --- /dev/null +++ b/arch/ia64/kernel/fsyscall_gtod_data.h @@ -0,0 +1,23 @@ +/* + * (c) Copyright 2007 Hewlett-Packard Development Company, L.P. + * Contributed by Peter Keilty + * + * fsyscall gettimeofday data + */ + +struct fsyscall_gtod_data_t { + seqlock_t lock; + struct timespec wall_time; + struct timespec monotonic_time; + cycle_t clk_mask; + u32 clk_mult; + u32 clk_shift; + void *clk_fsys_mmio; + cycle_t clk_cycle_last; +} __attribute__ ((aligned (L1_CACHE_BYTES))); + +struct itc_jitter_data_t { + int itc_jitter; + cycle_t itc_lastcycle; +} __attribute__ ((aligned (L1_CACHE_BYTES))); + diff --git a/arch/ia64/kernel/time.c b/arch/ia64/kernel/time.c index 3486fe7d6e65df00db95a4b93ff442cc2b14090d..627785c48ea95e495389653b5bfdc320967247df 100644 --- a/arch/ia64/kernel/time.c +++ b/arch/ia64/kernel/time.c @@ -19,6 +19,7 @@ #include #include #include +#include #include #include @@ -28,6 +29,16 @@ #include #include +#include "fsyscall_gtod_data.h" + +static cycle_t itc_get_cycles(void); + +struct fsyscall_gtod_data_t fsyscall_gtod_data = { + .lock = SEQLOCK_UNLOCKED, +}; + +struct itc_jitter_data_t itc_jitter_data; + volatile int time_keeper_id = 0; /* smp_processor_id() of time-keeper */ #ifdef CONFIG_IA64_DEBUG_IRQ @@ -37,11 +48,16 @@ EXPORT_SYMBOL(last_cli_ip); #endif -static struct time_interpolator itc_interpolator = { - .shift = 16, - .mask = 0xffffffffffffffffLL, - .source = TIME_SOURCE_CPU +static struct clocksource clocksource_itc = { + .name = "itc", + .rating = 350, + .read = itc_get_cycles, + .mask = 0xffffffffffffffff, + .mult = 0, /*to be caluclated*/ + .shift = 16, + .flags = CLOCK_SOURCE_IS_CONTINUOUS, }; +static struct clocksource *itc_clocksource; static irqreturn_t timer_interrupt (int irq, void *dev_id) @@ -210,8 +226,6 @@ ia64_init_itm (void) + itc_freq/2)/itc_freq; if (!(sal_platform_features & IA64_SAL_PLATFORM_FEATURE_ITC_DRIFT)) { - itc_interpolator.frequency = local_cpu_data->itc_freq; - itc_interpolator.drift = itc_drift; #ifdef CONFIG_SMP /* On IA64 in an SMP configuration ITCs are never accurately synchronized. * Jitter compensation requires a cmpxchg which may limit @@ -223,15 +237,50 @@ ia64_init_itm (void) * even going backward) if the ITC offsets between the individual CPUs * are too large. */ - if (!nojitter) itc_interpolator.jitter = 1; + if (!nojitter) + itc_jitter_data.itc_jitter = 1; #endif - register_time_interpolator(&itc_interpolator); } /* Setup the CPU local timer tick */ ia64_cpu_local_tick(); + + if (!itc_clocksource) { + /* Sort out mult/shift values: */ + clocksource_itc.mult = + clocksource_hz2mult(local_cpu_data->itc_freq, + clocksource_itc.shift); + clocksource_register(&clocksource_itc); + itc_clocksource = &clocksource_itc; + } } +static cycle_t itc_get_cycles() +{ + u64 lcycle, now, ret; + + if (!itc_jitter_data.itc_jitter) + return get_cycles(); + + lcycle = itc_jitter_data.itc_lastcycle; + now = get_cycles(); + if (lcycle && time_after(lcycle, now)) + return lcycle; + + /* + * Keep track of the last timer value returned. + * In an SMP environment, you could lose out in contention of + * cmpxchg. If so, your cmpxchg returns new value which the + * winner of contention updated to. Use the new value instead. + */ + ret = cmpxchg(&itc_jitter_data.itc_lastcycle, lcycle, now); + if (unlikely(ret != lcycle)) + return ret; + + return now; +} + + static struct irqaction timer_irqaction = { .handler = timer_interrupt, .flags = IRQF_DISABLED | IRQF_IRQPOLL, @@ -307,3 +356,34 @@ ia64_setup_printk_clock(void) if (!(sal_platform_features & IA64_SAL_PLATFORM_FEATURE_ITC_DRIFT)) ia64_printk_clock = ia64_itc_printk_clock; } + +void update_vsyscall(struct timespec *wall, struct clocksource *c) +{ + unsigned long flags; + + write_seqlock_irqsave(&fsyscall_gtod_data.lock, flags); + + /* copy fsyscall clock data */ + fsyscall_gtod_data.clk_mask = c->mask; + fsyscall_gtod_data.clk_mult = c->mult; + fsyscall_gtod_data.clk_shift = c->shift; + fsyscall_gtod_data.clk_fsys_mmio = c->fsys_mmio; + fsyscall_gtod_data.clk_cycle_last = c->cycle_last; + + /* copy kernel time structures */ + fsyscall_gtod_data.wall_time.tv_sec = wall->tv_sec; + fsyscall_gtod_data.wall_time.tv_nsec = wall->tv_nsec; + fsyscall_gtod_data.monotonic_time.tv_sec = wall_to_monotonic.tv_sec + + wall->tv_sec; + fsyscall_gtod_data.monotonic_time.tv_nsec = wall_to_monotonic.tv_nsec + + wall->tv_nsec; + + /* normalize */ + while (fsyscall_gtod_data.monotonic_time.tv_nsec >= NSEC_PER_SEC) { + fsyscall_gtod_data.monotonic_time.tv_nsec -= NSEC_PER_SEC; + fsyscall_gtod_data.monotonic_time.tv_sec++; + } + + write_sequnlock_irqrestore(&fsyscall_gtod_data.lock, flags); +} + diff --git a/arch/ia64/sn/kernel/sn2/timer.c b/arch/ia64/sn/kernel/sn2/timer.c index 56a88b6df4b41fbca0df635ab5fc23988b0298b4..19e25d2b64fcabdd003c7e239cf8938cc8200383 100644 --- a/arch/ia64/sn/kernel/sn2/timer.c +++ b/arch/ia64/sn/kernel/sn2/timer.c @@ -11,6 +11,7 @@ #include #include #include +#include #include #include @@ -22,11 +23,21 @@ extern unsigned long sn_rtc_cycles_per_second; -static struct time_interpolator sn2_interpolator = { - .drift = -1, - .shift = 10, - .mask = (1LL << 55) - 1, - .source = TIME_SOURCE_MMIO64 +static void __iomem *sn2_mc; + +static cycle_t read_sn2(void) +{ + return (cycle_t)readq(sn2_mc); +} + +static struct clocksource clocksource_sn2 = { + .name = "sn2_rtc", + .rating = 300, + .read = read_sn2, + .mask = (1LL << 55) - 1, + .mult = 0, + .shift = 10, + .flags = CLOCK_SOURCE_IS_CONTINUOUS, }; /* @@ -47,9 +58,11 @@ ia64_sn_udelay (unsigned long usecs) void __init sn_timer_init(void) { - sn2_interpolator.frequency = sn_rtc_cycles_per_second; - sn2_interpolator.addr = RTC_COUNTER_ADDR; - register_time_interpolator(&sn2_interpolator); + sn2_mc = RTC_COUNTER_ADDR; + clocksource_sn2.fsys_mmio = RTC_COUNTER_ADDR; + clocksource_sn2.mult = clocksource_hz2mult(sn_rtc_cycles_per_second, + clocksource_sn2.shift); + clocksource_register(&clocksource_sn2); ia64_udelay = &ia64_sn_udelay; } diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c index 80ffc782991631492d08c2dea2837972698e5193..bb5d23be42607fe4ebb3c91c6dd118287242131b 100644 --- a/drivers/acpi/processor_idle.c +++ b/drivers/acpi/processor_idle.c @@ -475,7 +475,7 @@ static void acpi_processor_idle(void) /* Get end time (ticks) */ t2 = inl(acpi_gbl_FADT.xpm_timer_block.address); -#ifdef CONFIG_GENERIC_TIME +#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86_TSC) /* TSC halts in C2, so notify users */ mark_tsc_unstable("possible TSC halt in C2"); #endif @@ -517,7 +517,7 @@ static void acpi_processor_idle(void) acpi_set_register(ACPI_BITREG_ARB_DISABLE, 0); } -#ifdef CONFIG_GENERIC_TIME +#if defined (CONFIG_GENERIC_TIME) && defined (CONFIG_X86_TSC) /* TSC halts in C3, so notify users */ mark_tsc_unstable("TSC halts in C3"); #endif diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c index 0be700f4e8fd7acdceaec7dd3acf0acdf63a00d3..ba0e74ad74bbbc778eb485ed95ae089b15cab6a1 100644 --- a/drivers/char/hpet.c +++ b/drivers/char/hpet.c @@ -29,6 +29,7 @@ #include #include #include +#include #include #include @@ -51,8 +52,34 @@ #define HPET_RANGE_SIZE 1024 /* from HPET spec */ +#if BITS_PER_LONG == 64 +#define write_counter(V, MC) writeq(V, MC) +#define read_counter(MC) readq(MC) +#else +#define write_counter(V, MC) writel(V, MC) +#define read_counter(MC) readl(MC) +#endif + static u32 hpet_nhpet, hpet_max_freq = HPET_USER_FREQ; +static void __iomem *hpet_mctr; + +static cycle_t read_hpet(void) +{ + return (cycle_t)read_counter((void __iomem *)hpet_mctr); +} + +static struct clocksource clocksource_hpet = { + .name = "hpet", + .rating = 250, + .read = read_hpet, + .mask = 0xffffffffffffffff, + .mult = 0, /*to be caluclated*/ + .shift = 10, + .flags = CLOCK_SOURCE_IS_CONTINUOUS, +}; +static struct clocksource *hpet_clocksource; + /* A lock for concurrent access by app and isr hpet activity. */ static DEFINE_SPINLOCK(hpet_lock); /* A lock for concurrent intermodule access to hpet and isr hpet activity. */ @@ -79,7 +106,7 @@ struct hpets { struct hpets *hp_next; struct hpet __iomem *hp_hpet; unsigned long hp_hpet_phys; - struct time_interpolator *hp_interpolator; + struct clocksource *hp_clocksource; unsigned long long hp_tick_freq; unsigned long hp_delta; unsigned int hp_ntimer; @@ -94,13 +121,6 @@ static struct hpets *hpets; #define HPET_PERIODIC 0x0004 #define HPET_SHARED_IRQ 0x0008 -#if BITS_PER_LONG == 64 -#define write_counter(V, MC) writeq(V, MC) -#define read_counter(MC) readq(MC) -#else -#define write_counter(V, MC) writel(V, MC) -#define read_counter(MC) readl(MC) -#endif #ifndef readq static inline unsigned long long readq(void __iomem *addr) @@ -737,27 +757,6 @@ static ctl_table dev_root[] = { static struct ctl_table_header *sysctl_header; -static void hpet_register_interpolator(struct hpets *hpetp) -{ -#ifdef CONFIG_TIME_INTERPOLATION - struct time_interpolator *ti; - - ti = kzalloc(sizeof(*ti), GFP_KERNEL); - if (!ti) - return; - - ti->source = TIME_SOURCE_MMIO64; - ti->shift = 10; - ti->addr = &hpetp->hp_hpet->hpet_mc; - ti->frequency = hpetp->hp_tick_freq; - ti->drift = HPET_DRIFT; - ti->mask = -1; - - hpetp->hp_interpolator = ti; - register_time_interpolator(ti); -#endif -} - /* * Adjustment for when arming the timer with * initial conditions. That is, main counter @@ -909,7 +908,16 @@ int hpet_alloc(struct hpet_data *hdp) } hpetp->hp_delta = hpet_calibrate(hpetp); - hpet_register_interpolator(hpetp); + + if (!hpet_clocksource) { + hpet_mctr = (void __iomem *)&hpetp->hp_hpet->hpet_mc; + CLKSRC_FSYS_MMIO_SET(clocksource_hpet.fsys_mmio, hpet_mctr); + clocksource_hpet.mult = clocksource_hz2mult(hpetp->hp_tick_freq, + clocksource_hpet.shift); + clocksource_register(&clocksource_hpet); + hpetp->hp_clocksource = &clocksource_hpet; + hpet_clocksource = &clocksource_hpet; + } return 0; } @@ -995,7 +1003,7 @@ static int hpet_acpi_add(struct acpi_device *device) static int hpet_acpi_remove(struct acpi_device *device, int type) { - /* XXX need to unregister interpolator, dealloc mem, etc */ + /* XXX need to unregister clocksource, dealloc mem, etc */ return -EINVAL; } diff --git a/include/linux/clocksource.h b/include/linux/clocksource.h index bf297b03a4e4650cd4c02a9dbe4e55307674411d..16ea3374dddf7a543501fca71718c5d72b885e07 100644 --- a/include/linux/clocksource.h +++ b/include/linux/clocksource.h @@ -67,6 +67,12 @@ struct clocksource { unsigned long flags; cycle_t (*vread)(void); void (*resume)(void); +#ifdef CONFIG_IA64 + void *fsys_mmio; /* used by fsyscall asm code */ +#define CLKSRC_FSYS_MMIO_SET(mmio, addr) ((mmio) = (addr)) +#else +#define CLKSRC_FSYS_MMIO_SET(mmio, addr) do { } while (0) +#endif /* timekeeping specific data, ignore */ cycle_t cycle_interval; diff --git a/include/linux/timex.h b/include/linux/timex.h index da929dbbea2a1c9ab246ee134bb83dcd9ec5c935..37ac3ff90fafb16f7814297d247c2a3c28c59204 100644 --- a/include/linux/timex.h +++ b/include/linux/timex.h @@ -224,66 +224,6 @@ static inline int ntp_synced(void) __x < 0 ? -(-__x >> __s) : __x >> __s; \ }) - -#ifdef CONFIG_TIME_INTERPOLATION - -#define TIME_SOURCE_CPU 0 -#define TIME_SOURCE_MMIO64 1 -#define TIME_SOURCE_MMIO32 2 -#define TIME_SOURCE_FUNCTION 3 - -/* For proper operations time_interpolator clocks must run slightly slower - * than the standard clock since the interpolator may only correct by having - * time jump forward during a tick. A slower clock is usually a side effect - * of the integer divide of the nanoseconds in a second by the frequency. - * The accuracy of the division can be increased by specifying a shift. - * However, this may cause the clock not to be slow enough. - * The interpolator will self-tune the clock by slowing down if no - * resets occur or speeding up if the time jumps per analysis cycle - * become too high. - * - * Setting jitter compensates for a fluctuating timesource by comparing - * to the last value read from the timesource to insure that an earlier value - * is not returned by a later call. The price to pay - * for the compensation is that the timer routines are not as scalable anymore. - */ - -struct time_interpolator { - u16 source; /* time source flags */ - u8 shift; /* increases accuracy of multiply by shifting. */ - /* Note that bits may be lost if shift is set too high */ - u8 jitter; /* if set compensate for fluctuations */ - u32 nsec_per_cyc; /* set by register_time_interpolator() */ - void *addr; /* address of counter or function */ - cycles_t mask; /* mask the valid bits of the counter */ - unsigned long offset; /* nsec offset at last update of interpolator */ - u64 last_counter; /* counter value in units of the counter at last update */ - cycles_t last_cycle; /* Last timer value if TIME_SOURCE_JITTER is set */ - u64 frequency; /* frequency in counts/second */ - long drift; /* drift in parts-per-million (or -1) */ - unsigned long skips; /* skips forward */ - unsigned long ns_skipped; /* nanoseconds skipped */ - struct time_interpolator *next; -}; - -extern void register_time_interpolator(struct time_interpolator *); -extern void unregister_time_interpolator(struct time_interpolator *); -extern void time_interpolator_reset(void); -extern unsigned long time_interpolator_get_offset(void); -extern void time_interpolator_update(long delta_nsec); - -#else /* !CONFIG_TIME_INTERPOLATION */ - -static inline void time_interpolator_reset(void) -{ -} - -static inline void time_interpolator_update(long delta_nsec) -{ -} - -#endif /* !CONFIG_TIME_INTERPOLATION */ - #define TICK_LENGTH_SHIFT 32 #ifdef CONFIG_NO_HZ diff --git a/kernel/time.c b/kernel/time.c index ffe19149d77006cb6c22db392b0a828962c655d3..e325597f5bf53fbe000605cd74b8c3ec5f94976e 100644 --- a/kernel/time.c +++ b/kernel/time.c @@ -136,7 +136,6 @@ static inline void warp_clock(void) write_seqlock_irq(&xtime_lock); wall_to_monotonic.tv_sec -= sys_tz.tz_minuteswest * 60; xtime.tv_sec += sys_tz.tz_minuteswest * 60; - time_interpolator_reset(); write_sequnlock_irq(&xtime_lock); clock_was_set(); } @@ -309,92 +308,6 @@ struct timespec timespec_trunc(struct timespec t, unsigned gran) } EXPORT_SYMBOL(timespec_trunc); -#ifdef CONFIG_TIME_INTERPOLATION -void getnstimeofday (struct timespec *tv) -{ - unsigned long seq,sec,nsec; - - do { - seq = read_seqbegin(&xtime_lock); - sec = xtime.tv_sec; - nsec = xtime.tv_nsec+time_interpolator_get_offset(); - } while (unlikely(read_seqretry(&xtime_lock, seq))); - - while (unlikely(nsec >= NSEC_PER_SEC)) { - nsec -= NSEC_PER_SEC; - ++sec; - } - tv->tv_sec = sec; - tv->tv_nsec = nsec; -} -EXPORT_SYMBOL_GPL(getnstimeofday); - -int do_settimeofday (struct timespec *tv) -{ - time_t wtm_sec, sec = tv->tv_sec; - long wtm_nsec, nsec = tv->tv_nsec; - - if ((unsigned long)tv->tv_nsec >= NSEC_PER_SEC) - return -EINVAL; - - write_seqlock_irq(&xtime_lock); - { - wtm_sec = wall_to_monotonic.tv_sec + (xtime.tv_sec - sec); - wtm_nsec = wall_to_monotonic.tv_nsec + (xtime.tv_nsec - nsec); - - set_normalized_timespec(&xtime, sec, nsec); - set_normalized_timespec(&wall_to_monotonic, wtm_sec, wtm_nsec); - - time_adjust = 0; /* stop active adjtime() */ - time_status |= STA_UNSYNC; - time_maxerror = NTP_PHASE_LIMIT; - time_esterror = NTP_PHASE_LIMIT; - time_interpolator_reset(); - } - write_sequnlock_irq(&xtime_lock); - clock_was_set(); - return 0; -} -EXPORT_SYMBOL(do_settimeofday); - -void do_gettimeofday (struct timeval *tv) -{ - unsigned long seq, nsec, usec, sec, offset; - do { - seq = read_seqbegin(&xtime_lock); - offset = time_interpolator_get_offset(); - sec = xtime.tv_sec; - nsec = xtime.tv_nsec; - } while (unlikely(read_seqretry(&xtime_lock, seq))); - - usec = (nsec + offset) / 1000; - - while (unlikely(usec >= USEC_PER_SEC)) { - usec -= USEC_PER_SEC; - ++sec; - } - - tv->tv_sec = sec; - tv->tv_usec = usec; - - /* - * Make sure xtime.tv_sec [returned by sys_time()] always - * follows the gettimeofday() result precisely. This - * condition is extremely unlikely, it can hit at most - * once per second: - */ - if (unlikely(xtime.tv_sec != tv->tv_sec)) { - unsigned long flags; - - write_seqlock_irqsave(&xtime_lock, flags); - update_wall_time(); - write_sequnlock_irqrestore(&xtime_lock, flags); - } -} -EXPORT_SYMBOL(do_gettimeofday); - -#else /* CONFIG_TIME_INTERPOLATION */ - #ifndef CONFIG_GENERIC_TIME /* * Simulate gettimeofday using do_gettimeofday which only allows a timeval @@ -410,7 +323,6 @@ void getnstimeofday(struct timespec *tv) } EXPORT_SYMBOL_GPL(getnstimeofday); #endif -#endif /* CONFIG_TIME_INTERPOLATION */ /* Converts Gregorian date to seconds since 1970-01-01 00:00:00. * Assumes input in normal date format, i.e. 1980-12-31 23:59:59 diff --git a/kernel/time/ntp.c b/kernel/time/ntp.c index 438c6b723ee202bd3a22607f2ebf7d4b031d1f6b..b5e352597cbb628091718d2ac486b59564a95cfc 100644 --- a/kernel/time/ntp.c +++ b/kernel/time/ntp.c @@ -116,11 +116,6 @@ void second_overflow(void) if (xtime.tv_sec % 86400 == 0) { xtime.tv_sec--; wall_to_monotonic.tv_sec++; - /* - * The timer interpolator will make time change - * gradually instead of an immediate jump by one second - */ - time_interpolator_update(-NSEC_PER_SEC); time_state = TIME_OOP; printk(KERN_NOTICE "Clock: inserting leap second " "23:59:60 UTC\n"); @@ -130,11 +125,6 @@ void second_overflow(void) if ((xtime.tv_sec + 1) % 86400 == 0) { xtime.tv_sec++; wall_to_monotonic.tv_sec--; - /* - * Use of time interpolator for a gradual change of - * time - */ - time_interpolator_update(NSEC_PER_SEC); time_state = TIME_WAIT; printk(KERN_NOTICE "Clock: deleting leap second " "23:59:59 UTC\n"); diff --git a/kernel/time/timekeeping.c b/kernel/time/timekeeping.c index 89698776613eb5c51d6dca9d385abc0dc0422bc3..88c81026e0039ae8cf16e3da6b1de223d3c96312 100644 --- a/kernel/time/timekeeping.c +++ b/kernel/time/timekeeping.c @@ -466,10 +466,6 @@ void update_wall_time(void) second_overflow(); } - /* interpolator bits */ - time_interpolator_update(clock->xtime_interval - >> clock->shift); - /* accumulate error between NTP and clock interval */ clock->error += current_tick_length(); clock->error -= clock->xtime_interval << (TICK_LENGTH_SHIFT - clock->shift); diff --git a/kernel/timer.c b/kernel/timer.c index d1e8b975c7aede3bb6b690efe0258f0eb84d1585..6ce1952eea7dbf84d4d9a4c3a5d03f8fd5bffbf3 100644 --- a/kernel/timer.c +++ b/kernel/timer.c @@ -1349,194 +1349,6 @@ void __init init_timers(void) open_softirq(TIMER_SOFTIRQ, run_timer_softirq, NULL); } -#ifdef CONFIG_TIME_INTERPOLATION - -struct time_interpolator *time_interpolator __read_mostly; -static struct time_interpolator *time_interpolator_list __read_mostly; -static DEFINE_SPINLOCK(time_interpolator_lock); - -static inline cycles_t time_interpolator_get_cycles(unsigned int src) -{ - unsigned long (*x)(void); - - switch (src) - { - case TIME_SOURCE_FUNCTION: - x = time_interpolator->addr; - return x(); - - case TIME_SOURCE_MMIO64 : - return readq_relaxed((void __iomem *)time_interpolator->addr); - - case TIME_SOURCE_MMIO32 : - return readl_relaxed((void __iomem *)time_interpolator->addr); - - default: return get_cycles(); - } -} - -static inline u64 time_interpolator_get_counter(int writelock) -{ - unsigned int src = time_interpolator->source; - - if (time_interpolator->jitter) - { - cycles_t lcycle; - cycles_t now; - - do { - lcycle = time_interpolator->last_cycle; - now = time_interpolator_get_cycles(src); - if (lcycle && time_after(lcycle, now)) - return lcycle; - - /* When holding the xtime write lock, there's no need - * to add the overhead of the cmpxchg. Readers are - * force to retry until the write lock is released. - */ - if (writelock) { - time_interpolator->last_cycle = now; - return now; - } - /* Keep track of the last timer value returned. The use of cmpxchg here - * will cause contention in an SMP environment. - */ - } while (unlikely(cmpxchg(&time_interpolator->last_cycle, lcycle, now) != lcycle)); - return now; - } - else - return time_interpolator_get_cycles(src); -} - -void time_interpolator_reset(void) -{ - time_interpolator->offset = 0; - time_interpolator->last_counter = time_interpolator_get_counter(1); -} - -#define GET_TI_NSECS(count,i) (((((count) - i->last_counter) & (i)->mask) * (i)->nsec_per_cyc) >> (i)->shift) - -unsigned long time_interpolator_get_offset(void) -{ - /* If we do not have a time interpolator set up then just return zero */ - if (!time_interpolator) - return 0; - - return time_interpolator->offset + - GET_TI_NSECS(time_interpolator_get_counter(0), time_interpolator); -} - -#define INTERPOLATOR_ADJUST 65536 -#define INTERPOLATOR_MAX_SKIP 10*INTERPOLATOR_ADJUST - -void time_interpolator_update(long delta_nsec) -{ - u64 counter; - unsigned long offset; - - /* If there is no time interpolator set up then do nothing */ - if (!time_interpolator) - return; - - /* - * The interpolator compensates for late ticks by accumulating the late - * time in time_interpolator->offset. A tick earlier than expected will - * lead to a reset of the offset and a corresponding jump of the clock - * forward. Again this only works if the interpolator clock is running - * slightly slower than the regular clock and the tuning logic insures - * that. - */ - - counter = time_interpolator_get_counter(1); - offset = time_interpolator->offset + - GET_TI_NSECS(counter, time_interpolator); - - if (delta_nsec < 0 || (unsigned long) delta_nsec < offset) - time_interpolator->offset = offset - delta_nsec; - else { - time_interpolator->skips++; - time_interpolator->ns_skipped += delta_nsec - offset; - time_interpolator->offset = 0; - } - time_interpolator->last_counter = counter; - - /* Tuning logic for time interpolator invoked every minute or so. - * Decrease interpolator clock speed if no skips occurred and an offset is carried. - * Increase interpolator clock speed if we skip too much time. - */ - if (jiffies % INTERPOLATOR_ADJUST == 0) - { - if (time_interpolator->skips == 0 && time_interpolator->offset > tick_nsec) - time_interpolator->nsec_per_cyc--; - if (time_interpolator->ns_skipped > INTERPOLATOR_MAX_SKIP && time_interpolator->offset == 0) - time_interpolator->nsec_per_cyc++; - time_interpolator->skips = 0; - time_interpolator->ns_skipped = 0; - } -} - -static inline int -is_better_time_interpolator(struct time_interpolator *new) -{ - if (!time_interpolator) - return 1; - return new->frequency > 2*time_interpolator->frequency || - (unsigned long)new->drift < (unsigned long)time_interpolator->drift; -} - -void -register_time_interpolator(struct time_interpolator *ti) -{ - unsigned long flags; - - /* Sanity check */ - BUG_ON(ti->frequency == 0 || ti->mask == 0); - - ti->nsec_per_cyc = ((u64)NSEC_PER_SEC << ti->shift) / ti->frequency; - spin_lock(&time_interpolator_lock); - write_seqlock_irqsave(&xtime_lock, flags); - if (is_better_time_interpolator(ti)) { - time_interpolator = ti; - time_interpolator_reset(); - } - write_sequnlock_irqrestore(&xtime_lock, flags); - - ti->next = time_interpolator_list; - time_interpolator_list = ti; - spin_unlock(&time_interpolator_lock); -} - -void -unregister_time_interpolator(struct time_interpolator *ti) -{ - struct time_interpolator *curr, **prev; - unsigned long flags; - - spin_lock(&time_interpolator_lock); - prev = &time_interpolator_list; - for (curr = *prev; curr; curr = curr->next) { - if (curr == ti) { - *prev = curr->next; - break; - } - prev = &curr->next; - } - - write_seqlock_irqsave(&xtime_lock, flags); - if (ti == time_interpolator) { - /* we lost the best time-interpolator: */ - time_interpolator = NULL; - /* find the next-best interpolator */ - for (curr = time_interpolator_list; curr; curr = curr->next) - if (is_better_time_interpolator(curr)) - time_interpolator = curr; - time_interpolator_reset(); - } - write_sequnlock_irqrestore(&xtime_lock, flags); - spin_unlock(&time_interpolator_lock); -} -#endif /* CONFIG_TIME_INTERPOLATION */ - /** * msleep - sleep safely even with waitqueue interruptions * @msecs: Time in milliseconds to sleep for