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authorLinus Torvalds <torvalds@linux-foundation.org>2017-09-05 09:45:46 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2017-09-05 09:45:46 -0700
commit9e85ae6af6e907975f68d82ff127073ec024cb05 (patch)
tree3d3349b03da858e53ef8f8dce467e4a691eabf88 /arch/s390/kernel/time.c
parentMerge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mattst88/alpha (diff)
parents390/mm: avoid empty zero pages for KVM guests to avoid postcopy hangs (diff)
downloadlinux-dev-9e85ae6af6e907975f68d82ff127073ec024cb05.tar.xz
linux-dev-9e85ae6af6e907975f68d82ff127073ec024cb05.zip
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux
Pull s390 updates from Martin Schwidefsky: "The first part of the s390 updates for 4.14: - Add machine type 0x3906 for IBM z14 - Add IBM z14 TLB flushing improvements for KVM guests - Exploit the TOD clock epoch extension to provide a continuous TOD clock afer 2042/09/17 - Add NIAI spinlock hints for IBM z14 - Rework the vmcp driver and use CMA for the respone buffer of z/VM CP commands - Drop some s390 specific asm headers and use the generic version - Add block discard for DASD-FBA devices under z/VM - Add average request times to DASD statistics - A few of those constify patches which seem to be in vogue right now - Cleanup and bug fixes" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux: (50 commits) s390/mm: avoid empty zero pages for KVM guests to avoid postcopy hangs s390/dasd: Add discard support for FBA devices s390/zcrypt: make CPRBX const s390/uaccess: avoid mvcos jump label s390/mm: use generic mm_hooks s390/facilities: fix typo s390/vmcp: simplify vmcp_response_free() s390/topology: Remove the unused parent_node() macro s390/dasd: Change unsigned long long to unsigned long s390/smp: convert cpuhp_setup_state() return code to zero on success s390: fix 'novx' early parameter handling s390/dasd: add average request times to dasd statistics s390/scm: use common completion path s390/pci: log changes to uid checking s390/vmcp: simplify vmcp_ioctl() s390/vmcp: return -ENOTTY for unknown ioctl commands s390/vmcp: split vmcp header file and move to uapi s390/vmcp: make use of contiguous memory allocator s390/cpcmd,vmcp: avoid GFP_DMA allocations s390/vmcp: fix uaccess check and avoid undefined behavior ...
Diffstat (limited to 'arch/s390/kernel/time.c')
-rw-r--r--arch/s390/kernel/time.c67
1 files changed, 46 insertions, 21 deletions
diff --git a/arch/s390/kernel/time.c b/arch/s390/kernel/time.c
index 192efdfac918..5cbd52169348 100644
--- a/arch/s390/kernel/time.c
+++ b/arch/s390/kernel/time.c
@@ -51,8 +51,15 @@
#include <asm/cio.h>
#include "entry.h"
-u64 sched_clock_base_cc = -1; /* Force to data section. */
-EXPORT_SYMBOL_GPL(sched_clock_base_cc);
+unsigned char tod_clock_base[16] __aligned(8) = {
+ /* Force to data section. */
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff
+};
+EXPORT_SYMBOL_GPL(tod_clock_base);
+
+u64 clock_comparator_max = -1ULL;
+EXPORT_SYMBOL_GPL(clock_comparator_max);
static DEFINE_PER_CPU(struct clock_event_device, comparators);
@@ -75,7 +82,7 @@ void __init time_early_init(void)
struct ptff_qui qui;
/* Initialize TOD steering parameters */
- tod_steering_end = sched_clock_base_cc;
+ tod_steering_end = *(unsigned long long *) &tod_clock_base[1];
vdso_data->ts_end = tod_steering_end;
if (!test_facility(28))
@@ -111,22 +118,27 @@ unsigned long long monotonic_clock(void)
}
EXPORT_SYMBOL(monotonic_clock);
-static void tod_to_timeval(__u64 todval, struct timespec64 *xt)
+static void ext_to_timespec64(unsigned char *clk, struct timespec64 *xt)
{
- unsigned long long sec;
+ unsigned long long high, low, rem, sec, nsec;
+
+ /* Split extendnd TOD clock to micro-seconds and sub-micro-seconds */
+ high = (*(unsigned long long *) clk) >> 4;
+ low = (*(unsigned long long *)&clk[7]) << 4;
+ /* Calculate seconds and nano-seconds */
+ sec = high;
+ rem = do_div(sec, 1000000);
+ nsec = (((low >> 32) + (rem << 32)) * 1000) >> 32;
- sec = todval >> 12;
- do_div(sec, 1000000);
xt->tv_sec = sec;
- todval -= (sec * 1000000) << 12;
- xt->tv_nsec = ((todval * 1000) >> 12);
+ xt->tv_nsec = nsec;
}
void clock_comparator_work(void)
{
struct clock_event_device *cd;
- S390_lowcore.clock_comparator = -1ULL;
+ S390_lowcore.clock_comparator = clock_comparator_max;
cd = this_cpu_ptr(&comparators);
cd->event_handler(cd);
}
@@ -148,7 +160,7 @@ void init_cpu_timer(void)
struct clock_event_device *cd;
int cpu;
- S390_lowcore.clock_comparator = -1ULL;
+ S390_lowcore.clock_comparator = clock_comparator_max;
set_clock_comparator(S390_lowcore.clock_comparator);
cpu = smp_processor_id();
@@ -179,7 +191,7 @@ static void clock_comparator_interrupt(struct ext_code ext_code,
unsigned long param64)
{
inc_irq_stat(IRQEXT_CLK);
- if (S390_lowcore.clock_comparator == -1ULL)
+ if (S390_lowcore.clock_comparator == clock_comparator_max)
set_clock_comparator(S390_lowcore.clock_comparator);
}
@@ -197,18 +209,28 @@ static void stp_reset(void);
void read_persistent_clock64(struct timespec64 *ts)
{
- __u64 clock;
+ unsigned char clk[STORE_CLOCK_EXT_SIZE];
+ __u64 delta;
- clock = get_tod_clock() - initial_leap_seconds;
- tod_to_timeval(clock - TOD_UNIX_EPOCH, ts);
+ delta = initial_leap_seconds + TOD_UNIX_EPOCH;
+ get_tod_clock_ext(clk);
+ *(__u64 *) &clk[1] -= delta;
+ if (*(__u64 *) &clk[1] > delta)
+ clk[0]--;
+ ext_to_timespec64(clk, ts);
}
void read_boot_clock64(struct timespec64 *ts)
{
- __u64 clock;
+ unsigned char clk[STORE_CLOCK_EXT_SIZE];
+ __u64 delta;
- clock = sched_clock_base_cc - initial_leap_seconds;
- tod_to_timeval(clock - TOD_UNIX_EPOCH, ts);
+ delta = initial_leap_seconds + TOD_UNIX_EPOCH;
+ memcpy(clk, tod_clock_base, 16);
+ *(__u64 *) &clk[1] -= delta;
+ if (*(__u64 *) &clk[1] > delta)
+ clk[0]--;
+ ext_to_timespec64(clk, ts);
}
static u64 read_tod_clock(struct clocksource *cs)
@@ -335,7 +357,7 @@ static unsigned long clock_sync_flags;
* source. If the clock mode is local it will return -EOPNOTSUPP and
* -EAGAIN if the clock is not in sync with the external reference.
*/
-int get_phys_clock(unsigned long long *clock)
+int get_phys_clock(unsigned long *clock)
{
atomic_t *sw_ptr;
unsigned int sw0, sw1;
@@ -406,7 +428,10 @@ static void clock_sync_global(unsigned long long delta)
struct ptff_qto qto;
/* Fixup the monotonic sched clock. */
- sched_clock_base_cc += delta;
+ *(unsigned long long *) &tod_clock_base[1] += delta;
+ if (*(unsigned long long *) &tod_clock_base[1] < delta)
+ /* Epoch overflow */
+ tod_clock_base[0]++;
/* Adjust TOD steering parameters. */
vdso_data->tb_update_count++;
now = get_tod_clock();
@@ -437,7 +462,7 @@ static void clock_sync_global(unsigned long long delta)
static void clock_sync_local(unsigned long long delta)
{
/* Add the delta to the clock comparator. */
- if (S390_lowcore.clock_comparator != -1ULL) {
+ if (S390_lowcore.clock_comparator != clock_comparator_max) {
S390_lowcore.clock_comparator += delta;
set_clock_comparator(S390_lowcore.clock_comparator);
}