[broonie-ci:arm64-sve-trap-mitigation 3/3] arch/arm64/kernel/entry-common.c:258:30: warning: unused variable 'sve_vq_minus_one'

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

tree:   https://git.kernel.org/pub/scm/linux/kernel/git/broonie/ci.git arm64-sve-trap-mitigation
head:   00a72da058c10512a992dd75733d08daed8437fc
commit: 00a72da058c10512a992dd75733d08daed8437fc [3/3] arm64/sve: Disable TIF_SVE on syscall once per second
config: arm64-allnoconfig-bpf (https://download.01.org/0day-ci/archive/20260702/202607020044.UmATj7HQ-lkp@intel.com/config)
compiler: aarch64-linux-gnu-gcc (Debian 14.2.0-19) 14.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260702/202607020044.UmATj7HQ-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/202607020044.UmATj7HQ-lkp@intel.com/

All warnings (new ones prefixed by >>):

   arch/arm64/kernel/entry-common.c: In function 'fpsimd_syscall_enter':
>> arch/arm64/kernel/entry-common.c:258:30: warning: unused variable 'sve_vq_minus_one' [-Wunused-variable]
     258 |                 unsigned int sve_vq_minus_one;
         |                              ^~~~~~~~~~~~~~~~


vim +/sve_vq_minus_one +258 arch/arm64/kernel/entry-common.c

   239	
   240	/*
   241	 * As per the ABI exit SME streaming mode and clear the SVE state not
   242	 * shared with FPSIMD on syscall entry.
   243	 */
   244	static inline void fpsimd_syscall_enter(void)
   245	{
   246		/* Ensure PSTATE.SM is clear, but leave PSTATE.ZA as-is. */
   247		if (system_supports_sme())
   248			sme_smstop_sm();
   249	
   250		/*
   251		 * The CPU is not in streaming mode. If non-streaming SVE is not
   252		 * supported, there is no SVE state that needs to be discarded.
   253		 */
   254		if (!system_supports_sve())
   255			return;
   256	
   257		if (test_thread_flag(TIF_SVE)) {
 > 258			unsigned int sve_vq_minus_one;
   259	
   260			/*
   261			 * Ensure that tasks that don't block in a syscall
   262			 * also get a chance to drop TIF_SVE.
   263			 */
   264			if (unlikely(time_after(jiffies,
   265						current->thread.sve_timeout))) {
   266				clear_thread_flag(TIF_SVE);
   267				sve_user_disable();
   268			} else {
   269				sve_flush_live();
   270			}
   271		}
   272	
   273		/*
   274		 * Any live non-FPSIMD SVE state has been zeroed. Allow
   275		 * fpsimd_save_user_state() to lazily discard SVE state until either
   276		 * the live state is unbound or fpsimd_syscall_exit() is called.
   277		 */
   278		__this_cpu_write(fpsimd_last_state.to_save, FP_STATE_FPSIMD);
   279	}
   280	

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