[freescale-fslc:pr/642 2702/30000] drivers/char/imx_amp/imx_sema4.c:122:5: warning: no previous prototype for '_imx_sema4_mutex_lock'

[kernel test robot <lkp@intel.com>]

tree:   https://github.com/Freescale/linux-fslc pr/642
head:   c8b7cf62c7fea8456dec789d550b8006d73b8f04
commit: 08dcfadc9a22bdb8cd37bc1ce38bc98d202cd857 [2702/30000] Merge branch 'pm/next' into next
config: arm-defconfig (https://download.01.org/0day-ci/archive/20231015/202310151920.oUMZuw0a-lkp@intel.com/config)
compiler: arm-linux-gnueabi-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231015/202310151920.oUMZuw0a-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202310151920.oUMZuw0a-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> drivers/clk/imx/clk-imx6sx.c:136:6: warning: no previous prototype for 'imx6sx_set_m4_highfreq' [-Wmissing-prototypes]
     136 | void imx6sx_set_m4_highfreq(bool high_freq)
         |      ^~~~~~~~~~~~~~~~~~~~~~
   In file included from drivers/clk/imx/clk-imx6sx.c:13:
   include/linux/imx_sema4.h:32:27: warning: 'idx_sema4' defined but not used [-Wunused-const-variable=]
      32 | static const unsigned int idx_sema4[SEMA4_NUM_GATES] = {
         |                           ^~~~~~~~~
--
>> drivers/char/imx_amp/imx_sema4.c:122:5: warning: no previous prototype for '_imx_sema4_mutex_lock' [-Wmissing-prototypes]
     122 | int _imx_sema4_mutex_lock(struct imx_sema4_mutex *mutex_ptr)
         |     ^~~~~~~~~~~~~~~~~~~~~


vim +/_imx_sema4_mutex_lock +122 drivers/char/imx_amp/imx_sema4.c

f17252c51016f7 Anson Huang 2019-04-19  107  
f17252c51016f7 Anson Huang 2019-04-19  108  /*!
f17252c51016f7 Anson Huang 2019-04-19  109   * \brief Lock the mutex, shouldn't be interruted by INT.
f17252c51016f7 Anson Huang 2019-04-19  110   *
f17252c51016f7 Anson Huang 2019-04-19  111   * This function attempts to lock a mutex. If the mutex is already locked
f17252c51016f7 Anson Huang 2019-04-19  112   * by another task the function return -EBUSY, and tell invoker wait until
f17252c51016f7 Anson Huang 2019-04-19  113   * it is possible to lock the mutex.
f17252c51016f7 Anson Huang 2019-04-19  114   *
f17252c51016f7 Anson Huang 2019-04-19  115   * \param[in] mutex_ptr   Pointer to mutex structure.
f17252c51016f7 Anson Huang 2019-04-19  116   *
f17252c51016f7 Anson Huang 2019-04-19  117   * \return MQX_INVALID_POINTER (Wrong pointer to the mutex structure provided.)
f17252c51016f7 Anson Huang 2019-04-19  118   * \return COREMUTEX_OK (mutex successfully locked.)
f17252c51016f7 Anson Huang 2019-04-19  119   *
f17252c51016f7 Anson Huang 2019-04-19  120   * \see imx_sema4_mutex_unlock
f17252c51016f7 Anson Huang 2019-04-19  121   */
f17252c51016f7 Anson Huang 2019-04-19 @122  int _imx_sema4_mutex_lock(struct imx_sema4_mutex *mutex_ptr)
f17252c51016f7 Anson Huang 2019-04-19  123  {
f17252c51016f7 Anson Huang 2019-04-19  124  	int ret = 0, i = 0;
f17252c51016f7 Anson Huang 2019-04-19  125  
f17252c51016f7 Anson Huang 2019-04-19  126  	if ((mutex_ptr == NULL) || (mutex_ptr->valid != CORE_MUTEX_VALID))
f17252c51016f7 Anson Huang 2019-04-19  127  		return -EINVAL;
f17252c51016f7 Anson Huang 2019-04-19  128  
f17252c51016f7 Anson Huang 2019-04-19  129  	i = mutex_ptr->gate_num;
f17252c51016f7 Anson Huang 2019-04-19  130  	mutex_ptr->gate_val = readb(imx6_sema4->ioaddr + i);
f17252c51016f7 Anson Huang 2019-04-19  131  	mutex_ptr->gate_val &= SEMA4_GATE_MASK;
f17252c51016f7 Anson Huang 2019-04-19  132  	/* Check to see if this core already own it */
f17252c51016f7 Anson Huang 2019-04-19  133  	if (mutex_ptr->gate_val == SEMA4_A9_LOCK) {
f17252c51016f7 Anson Huang 2019-04-19  134  		/* return -EBUSY, invoker should be in sleep, and re-lock ag */
f17252c51016f7 Anson Huang 2019-04-19  135  		pr_err("%s -> %s %d already locked, wait! num %d val %d.\n",
f17252c51016f7 Anson Huang 2019-04-19  136  				__FILE__, __func__, __LINE__,
f17252c51016f7 Anson Huang 2019-04-19  137  				i, mutex_ptr->gate_val);
f17252c51016f7 Anson Huang 2019-04-19  138  		ret = -EBUSY;
f17252c51016f7 Anson Huang 2019-04-19  139  		goto out;
f17252c51016f7 Anson Huang 2019-04-19  140  	} else {
f17252c51016f7 Anson Huang 2019-04-19  141  		/* try to lock the mutex */
f17252c51016f7 Anson Huang 2019-04-19  142  		mutex_ptr->gate_val = readb(imx6_sema4->ioaddr + i);
f17252c51016f7 Anson Huang 2019-04-19  143  		mutex_ptr->gate_val &= (~SEMA4_GATE_MASK);
f17252c51016f7 Anson Huang 2019-04-19  144  		mutex_ptr->gate_val |= SEMA4_A9_LOCK;
f17252c51016f7 Anson Huang 2019-04-19  145  		writeb(mutex_ptr->gate_val, imx6_sema4->ioaddr + i);
f17252c51016f7 Anson Huang 2019-04-19  146  		mutex_ptr->gate_val = readb(imx6_sema4->ioaddr + i);
f17252c51016f7 Anson Huang 2019-04-19  147  		mutex_ptr->gate_val &= SEMA4_GATE_MASK;
f17252c51016f7 Anson Huang 2019-04-19  148  		/* double check the mutex is locked, otherwise, return -EBUSY */
f17252c51016f7 Anson Huang 2019-04-19  149  		if (mutex_ptr->gate_val != SEMA4_A9_LOCK) {
f17252c51016f7 Anson Huang 2019-04-19  150  			pr_debug("wait-locked num %d val %d.\n",
f17252c51016f7 Anson Huang 2019-04-19  151  					i, mutex_ptr->gate_val);
f17252c51016f7 Anson Huang 2019-04-19  152  			ret = -EBUSY;
f17252c51016f7 Anson Huang 2019-04-19  153  		}
f17252c51016f7 Anson Huang 2019-04-19  154  	}
f17252c51016f7 Anson Huang 2019-04-19  155  out:
f17252c51016f7 Anson Huang 2019-04-19  156  	return ret;
f17252c51016f7 Anson Huang 2019-04-19  157  }
f17252c51016f7 Anson Huang 2019-04-19  158  

:::::: The code at line 122 was first introduced by commit
:::::: f17252c51016f757f54211818d9850202c354b90 char: imx_amp: add sema4 driver support

:::::: TO: Anson Huang <Anson.Huang@nxp.com>
:::::: CC: Dong Aisheng <aisheng.dong@nxp.com>

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