Re: [PATCH v8 1/6] MIPS: JZ4780: Introduce SMP support.

[kbuild test robot]

Hi "åçæ,

Thank you for the patch! Perhaps something to improve:

[auto build test WARNING on robh/for-next]
[also build test WARNING on tip/timers/core linus/master v5.7-rc6]
[cannot apply to linux/master next-20200518]
[if your patch is applied to the wrong git tree, please drop us a note to help
improve the system. BTW, we also suggest to use '--base' option to specify the
base tree in git format-patch, please see https://stackoverflow.com/a/37406982]

url:    https://github.com/0day-ci/linux/commits/Zhou-Yanjie/Introduce-SMP-support-for-CI20-based-on-JZ4780/20200519-224008
base:   https://git.kernel.org/pub/scm/linux/kernel/git/robh/linux.git for-next
config: mips-allyesconfig (attached as .config)
compiler: mips-linux-gcc (GCC) 9.3.0
reproduce:
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # save the attached .config to linux build tree
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=gcc-9.3.0 make.cross ARCH=mips 

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

All warnings (new ones prefixed by >>, old ones prefixed by <<):

>> arch/mips/kernel/idle.c:97:6: warning: no previous prototype for 'jz4780_smp_wait_irqoff' [-Wmissing-prototypes]
97 | void jz4780_smp_wait_irqoff(void)
|      ^~~~~~~~~~~~~~~~~~~~~~
arch/mips/kernel/idle.c:155:13: warning: no previous prototype for 'check_wait' [-Wmissing-prototypes]
155 | void __init check_wait(void)
|             ^~~~~~~~~~

vim +/jz4780_smp_wait_irqoff +97 arch/mips/kernel/idle.c

    90	
    91	/*
    92	 * The Ingenic jz4780 SMP variant has to write back dirty cache lines before
    93	 * executing wait. The CPU & cache clock will be gated until we return from
    94	 * the wait, and if another core attempts to access data from our data cache
    95	 * during this time then it will lock up.
    96	 */
  > 97	void jz4780_smp_wait_irqoff(void)
    98	{
    99		unsigned long pending = read_c0_cause() & read_c0_status() & CAUSEF_IP;
   100	
   101		/*
   102		 * Going to idle has a significant overhead due to the cache flush so
   103		 * try to avoid it if we'll immediately be woken again due to an IRQ.
   104		 */
   105		if (!need_resched() && !pending) {
   106			r4k_blast_dcache();
   107	
   108			__asm__(
   109			"	.set push	\n"
   110			"	.set mips3	\n"
   111			"	sync		\n"
   112			"	wait		\n"
   113			"	.set pop	\n");
   114		}
   115	
   116		local_irq_enable();
   117	}
   118	

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

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