[jirislaby:devel 26/50] arch/x86/events/intel/ds.c:1680:9: sparse: sparse: too long token expansion

[jirislaby:devel 26/50] arch/x86/events/intel/ds.c:1680:9: sparse: sparse: too long token expansion

[kbuild test robot]

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tree:   https://git.kernel.org/pub/scm/linux/kernel/git/jirislaby/linux.git devel
head:   ee0ee29f0a9eee7ef2b4db85375544fd048f8343
commit: 04ee605f3b4a02028b5247e8160e006c66bd5b74 [26/50] include condition in the BUG_ON/WARN_ON output
config: i386-randconfig-s001-20200602 (attached as .config)
compiler: gcc-9 (Debian 9.3.0-13) 9.3.0
reproduce:
        # apt-get install sparse
        # sparse version: v0.6.1-244-g0ee050a8-dirty
        git checkout 04ee605f3b4a02028b5247e8160e006c66bd5b74
        # save the attached .config to linux build tree
        make W=1 C=1 ARCH=i386 CF='-fdiagnostic-prefix -D__CHECK_ENDIAN__'

If you fix the issue, kindly add following tag as appropriate
Reported-by: kbuild test robot <lkp@intel.com>


sparse warnings: (new ones prefixed by >>)

>> arch/x86/events/intel/ds.c:1680:9: sparse: sparse: too long token expansion

vim +1680 arch/x86/events/intel/ds.c

5bee2cc69d986e2 Kan Liang 2018-02-12  1662  
d31fc13fdcb20e1 Kan Liang 2018-02-12  1663  /*
d31fc13fdcb20e1 Kan Liang 2018-02-12  1664   * Special variant of intel_pmu_save_and_restart() for auto-reload.
d31fc13fdcb20e1 Kan Liang 2018-02-12  1665   */
d31fc13fdcb20e1 Kan Liang 2018-02-12  1666  static int
d31fc13fdcb20e1 Kan Liang 2018-02-12  1667  intel_pmu_save_and_restart_reload(struct perf_event *event, int count)
d31fc13fdcb20e1 Kan Liang 2018-02-12  1668  {
d31fc13fdcb20e1 Kan Liang 2018-02-12  1669  	struct hw_perf_event *hwc = &event->hw;
d31fc13fdcb20e1 Kan Liang 2018-02-12  1670  	int shift = 64 - x86_pmu.cntval_bits;
d31fc13fdcb20e1 Kan Liang 2018-02-12  1671  	u64 period = hwc->sample_period;
d31fc13fdcb20e1 Kan Liang 2018-02-12  1672  	u64 prev_raw_count, new_raw_count;
d31fc13fdcb20e1 Kan Liang 2018-02-12  1673  	s64 new, old;
d31fc13fdcb20e1 Kan Liang 2018-02-12  1674  
d31fc13fdcb20e1 Kan Liang 2018-02-12  1675  	WARN_ON(!period);
d31fc13fdcb20e1 Kan Liang 2018-02-12  1676  
d31fc13fdcb20e1 Kan Liang 2018-02-12  1677  	/*
d31fc13fdcb20e1 Kan Liang 2018-02-12  1678  	 * drain_pebs() only happens when the PMU is disabled.
d31fc13fdcb20e1 Kan Liang 2018-02-12  1679  	 */
d31fc13fdcb20e1 Kan Liang 2018-02-12 @1680  	WARN_ON(this_cpu_read(cpu_hw_events.enabled));
d31fc13fdcb20e1 Kan Liang 2018-02-12  1681  
d31fc13fdcb20e1 Kan Liang 2018-02-12  1682  	prev_raw_count = local64_read(&hwc->prev_count);
d31fc13fdcb20e1 Kan Liang 2018-02-12  1683  	rdpmcl(hwc->event_base_rdpmc, new_raw_count);
d31fc13fdcb20e1 Kan Liang 2018-02-12  1684  	local64_set(&hwc->prev_count, new_raw_count);
d31fc13fdcb20e1 Kan Liang 2018-02-12  1685  
d31fc13fdcb20e1 Kan Liang 2018-02-12  1686  	/*
d31fc13fdcb20e1 Kan Liang 2018-02-12  1687  	 * Since the counter increments a negative counter value and
d31fc13fdcb20e1 Kan Liang 2018-02-12  1688  	 * overflows on the sign switch, giving the interval:
d31fc13fdcb20e1 Kan Liang 2018-02-12  1689  	 *
d31fc13fdcb20e1 Kan Liang 2018-02-12  1690  	 *   [-period, 0]
d31fc13fdcb20e1 Kan Liang 2018-02-12  1691  	 *
d31fc13fdcb20e1 Kan Liang 2018-02-12  1692  	 * the difference between two consequtive reads is:
d31fc13fdcb20e1 Kan Liang 2018-02-12  1693  	 *
d31fc13fdcb20e1 Kan Liang 2018-02-12  1694  	 *   A) value2 - value1;
d31fc13fdcb20e1 Kan Liang 2018-02-12  1695  	 *      when no overflows have happened in between,
d31fc13fdcb20e1 Kan Liang 2018-02-12  1696  	 *
d31fc13fdcb20e1 Kan Liang 2018-02-12  1697  	 *   B) (0 - value1) + (value2 - (-period));
d31fc13fdcb20e1 Kan Liang 2018-02-12  1698  	 *      when one overflow happened in between,
d31fc13fdcb20e1 Kan Liang 2018-02-12  1699  	 *
d31fc13fdcb20e1 Kan Liang 2018-02-12  1700  	 *   C) (0 - value1) + (n - 1) * (period) + (value2 - (-period));
d31fc13fdcb20e1 Kan Liang 2018-02-12  1701  	 *      when @n overflows happened in between.
d31fc13fdcb20e1 Kan Liang 2018-02-12  1702  	 *
d31fc13fdcb20e1 Kan Liang 2018-02-12  1703  	 * Here A) is the obvious difference, B) is the extension to the
d31fc13fdcb20e1 Kan Liang 2018-02-12  1704  	 * discrete interval, where the first term is to the top of the
d31fc13fdcb20e1 Kan Liang 2018-02-12  1705  	 * interval and the second term is from the bottom of the next
d31fc13fdcb20e1 Kan Liang 2018-02-12  1706  	 * interval and C) the extension to multiple intervals, where the
d31fc13fdcb20e1 Kan Liang 2018-02-12  1707  	 * middle term is the whole intervals covered.
d31fc13fdcb20e1 Kan Liang 2018-02-12  1708  	 *
d31fc13fdcb20e1 Kan Liang 2018-02-12  1709  	 * An equivalent of C, by reduction, is:
d31fc13fdcb20e1 Kan Liang 2018-02-12  1710  	 *
d31fc13fdcb20e1 Kan Liang 2018-02-12  1711  	 *   value2 - value1 + n * period
d31fc13fdcb20e1 Kan Liang 2018-02-12  1712  	 */
d31fc13fdcb20e1 Kan Liang 2018-02-12  1713  	new = ((s64)(new_raw_count << shift) >> shift);
d31fc13fdcb20e1 Kan Liang 2018-02-12  1714  	old = ((s64)(prev_raw_count << shift) >> shift);
d31fc13fdcb20e1 Kan Liang 2018-02-12  1715  	local64_add(new - old + count * period, &event->count);
d31fc13fdcb20e1 Kan Liang 2018-02-12  1716  
f861854e1b435b2 Kan Liang 2020-01-21  1717  	local64_set(&hwc->period_left, -new);
f861854e1b435b2 Kan Liang 2020-01-21  1718  
d31fc13fdcb20e1 Kan Liang 2018-02-12  1719  	perf_event_update_userpage(event);
d31fc13fdcb20e1 Kan Liang 2018-02-12  1720  
d31fc13fdcb20e1 Kan Liang 2018-02-12  1721  	return 0;
d31fc13fdcb20e1 Kan Liang 2018-02-12  1722  }
d31fc13fdcb20e1 Kan Liang 2018-02-12  1723  

:::::: The code at line 1680 was first introduced by commit
:::::: d31fc13fdcb20e1c317f9a7dd6273c18fbd58308 perf/x86/intel: Fix event update for auto-reload

:::::: TO: Kan Liang <kan.liang@linux.intel.com>
:::::: CC: Ingo Molnar <mingo@kernel.org>

---
0-DAY CI Kernel Test Service, Intel Corporation
https://lists.01.org/hyperkitty/list/kbuild-all(a)lists.01.org

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