[linux-next:master 10184/11353] drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_device_queue_manager.c:508:6: warning: variable 'vmid' is used uninitialized whenever 'if' condition is false

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

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master
head:   cb153b68ff91cbc434f3de70ac549e110543e1bb
commit: c8b0507f40deea3d5014b5b4989b6a06ffedde70 [10184/11353] drm/amdkfd: judge get_atc_vmid_pasid_mapping_info before call
config: arm64-allmodconfig (https://download.01.org/0day-ci/archive/20220309/202203090313.LRIlHhjL-lkp@intel.com/config)
compiler: clang version 15.0.0 (https://github.com/llvm/llvm-project d271fc04d5b97b12e6b797c6067d3c96a8d7470e)
reproduce (this is a W=1 build):
        wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
        chmod +x ~/bin/make.cross
        # install arm64 cross compiling tool for clang build
        # apt-get install binutils-aarch64-linux-gnu
        # https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/commit/?id=c8b0507f40deea3d5014b5b4989b6a06ffedde70
        git remote add linux-next https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
        git fetch --no-tags linux-next master
        git checkout c8b0507f40deea3d5014b5b4989b6a06ffedde70
        # save the config file to linux build tree
        mkdir build_dir
        COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=arm64 SHELL=/bin/bash drivers/gpu/

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

All warnings (new ones prefixed by >>):

>> drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_device_queue_manager.c:508:6: warning: variable 'vmid' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
           if (dev->kfd2kgd->get_atc_vmid_pasid_mapping_info) {
               ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_device_queue_manager.c:521:6: note: uninitialized use occurs here
           if (vmid > last_vmid_to_scan) {
               ^~~~
   drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_device_queue_manager.c:508:2: note: remove the 'if' if its condition is always true
           if (dev->kfd2kgd->get_atc_vmid_pasid_mapping_info) {
           ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
   drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_device_queue_manager.c:490:19: note: initialize the variable 'vmid' to silence this warning
           unsigned int vmid;
                            ^
                             = 0
   1 warning generated.


vim +508 drivers/gpu/drm/amd/amdgpu/../amdkfd/kfd_device_queue_manager.c

   486	
   487	static int dbgdev_wave_reset_wavefronts(struct kfd_dev *dev, struct kfd_process *p)
   488	{
   489		int status = 0;
   490		unsigned int vmid;
   491		uint16_t queried_pasid;
   492		union SQ_CMD_BITS reg_sq_cmd;
   493		union GRBM_GFX_INDEX_BITS reg_gfx_index;
   494		struct kfd_process_device *pdd;
   495		int first_vmid_to_scan = dev->vm_info.first_vmid_kfd;
   496		int last_vmid_to_scan = dev->vm_info.last_vmid_kfd;
   497	
   498		reg_sq_cmd.u32All = 0;
   499		reg_gfx_index.u32All = 0;
   500	
   501		pr_debug("Killing all process wavefronts\n");
   502	
   503		/* Scan all registers in the range ATC_VMID8_PASID_MAPPING ..
   504		 * ATC_VMID15_PASID_MAPPING
   505		 * to check which VMID the current process is mapped to.
   506		 */
   507	
 > 508		if (dev->kfd2kgd->get_atc_vmid_pasid_mapping_info) {
   509			for (vmid = first_vmid_to_scan; vmid <= last_vmid_to_scan; vmid++) {
   510				status = dev->kfd2kgd->get_atc_vmid_pasid_mapping_info
   511						(dev->adev, vmid, &queried_pasid);
   512	
   513				if (status && queried_pasid == p->pasid) {
   514					pr_debug("Killing wave fronts of vmid %d and pasid 0x%x\n",
   515							vmid, p->pasid);
   516					break;
   517				}
   518			}
   519		}
   520	
   521		if (vmid > last_vmid_to_scan) {
   522			pr_err("Didn't find vmid for pasid 0x%x\n", p->pasid);
   523			return -EFAULT;
   524		}
   525	
   526		/* taking the VMID for that process on the safe way using PDD */
   527		pdd = kfd_get_process_device_data(dev, p);
   528		if (!pdd)
   529			return -EFAULT;
   530	
   531		reg_gfx_index.bits.sh_broadcast_writes = 1;
   532		reg_gfx_index.bits.se_broadcast_writes = 1;
   533		reg_gfx_index.bits.instance_broadcast_writes = 1;
   534		reg_sq_cmd.bits.mode = SQ_IND_CMD_MODE_BROADCAST;
   535		reg_sq_cmd.bits.cmd = SQ_IND_CMD_CMD_KILL;
   536		reg_sq_cmd.bits.vm_id = vmid;
   537	
   538		dev->kfd2kgd->wave_control_execute(dev->adev,
   539						reg_gfx_index.u32All,
   540						reg_sq_cmd.u32All);
   541	
   542		return 0;
   543	}
   544	

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