[IA64] Convert to generic timekeeping/clocksource
authorTony Luck <tony.luck@intel.com>
Fri, 20 Jul 2007 18:22:30 +0000 (11:22 -0700)
committerTony Luck <tony.luck@intel.com>
Fri, 20 Jul 2007 18:22:30 +0000 (11:22 -0700)
This is a merge of Peter Keilty's initial patch (which was
revived by Bob Picco) for this with Hidetoshi Seto's fixes
and scaling improvements.

Acked-by: Bob Picco <bob.picco@hp.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>
18 files changed:
Documentation/kernel-parameters.txt
arch/ia64/Kconfig
arch/ia64/configs/bigsur_defconfig
arch/ia64/configs/gensparse_defconfig
arch/ia64/configs/sim_defconfig
arch/ia64/configs/sn2_defconfig
arch/ia64/configs/tiger_defconfig
arch/ia64/configs/zx1_defconfig
arch/ia64/defconfig
arch/ia64/kernel/asm-offsets.c
arch/ia64/kernel/cyclone.c
arch/ia64/kernel/fsys.S
arch/ia64/kernel/fsyscall_gtod_data.h [new file with mode: 0644]
arch/ia64/kernel/time.c
arch/ia64/sn/kernel/sn2/timer.c
drivers/acpi/processor_idle.c
drivers/char/hpet.c
include/linux/clocksource.h

index 9a54148..68115d7 100644 (file)
@@ -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.
index 616c96e..36c7b96 100644 (file)
@@ -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
 
index 90e9c2e..9eb48c0 100644 (file)
@@ -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
index 0d29aa2..3a9ed95 100644 (file)
@@ -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
index d9146c3..c420d9f 100644 (file)
@@ -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
index 64e951d..4c9ffc4 100644 (file)
@@ -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
index a144693..e208747 100644 (file)
@@ -98,7 +98,7 @@ 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
index 1c7955c..4a060fc 100644 (file)
@@ -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
index 90bd960..461f8ee 100644 (file)
@@ -98,7 +98,7 @@ 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
index 2236fab..0aebc6f 100644 (file)
@@ -7,6 +7,7 @@
 #define ASM_OFFSETS_C 1
 
 #include <linux/sched.h>
+#include <linux/clocksource.h>
 
 #include <asm-ia64/processor.h>
 #include <asm-ia64/ptrace.h>
@@ -15,6 +16,7 @@
 #include <asm-ia64/mca.h>
 
 #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));
 }
index e00b215..2fd96d9 100644 (file)
@@ -3,6 +3,7 @@
 #include <linux/time.h>
 #include <linux/errno.h>
 #include <linux/timex.h>
+#include <linux/clocksource.h>
 #include <asm/io.h>
 
 /* 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;
 }
index 3f926c2..4484197 100644 (file)
@@ -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 (file)
index 0000000..490dab5
--- /dev/null
@@ -0,0 +1,23 @@
+/*
+ * (c) Copyright 2007 Hewlett-Packard Development Company, L.P.
+ *        Contributed by Peter Keilty <peter.keilty@hp.com>
+ *
+ * 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)));
+
index 3486fe7..627785c 100644 (file)
@@ -19,6 +19,7 @@
 #include <linux/interrupt.h>
 #include <linux/efi.h>
 #include <linux/timex.h>
+#include <linux/clocksource.h>
 
 #include <asm/machvec.h>
 #include <asm/delay.h>
 #include <asm/sections.h>
 #include <asm/system.h>
 
+#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);
+}
+
index 56a88b6..19e25d2 100644 (file)
@@ -11,6 +11,7 @@
 #include <linux/sched.h>
 #include <linux/time.h>
 #include <linux/interrupt.h>
+#include <linux/clocksource.h>
 
 #include <asm/hw_irq.h>
 #include <asm/system.h>
 
 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;
 }
index 80ffc78..bb5d23b 100644 (file)
@@ -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
index 0be700f..ba0e74a 100644 (file)
@@ -29,6 +29,7 @@
 #include <linux/bcd.h>
 #include <linux/seq_file.h>
 #include <linux/bitops.h>
+#include <linux/clocksource.h>
 
 #include <asm/current.h>
 #include <asm/uaccess.h>
 
 #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;
 }
 
index bf297b0..16ea337 100644 (file)
@@ -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;