arch/x86/kernel/cpu/mtrr/generic.c:259: warning: Function parameter or member 'var' not described in 'mtrr_overwrite_state'

From: kernel test robot
Date: Thu Aug 17 2023 - 02:40:07 EST


tree: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git master
head: 4853c74bd7ab7fdb83f319bd9ace8a08c031e9b6
commit: 29055dc74287467bd7a053d60b4afe753832960d x86/mtrr: Support setting MTRR state for software defined MTRRs
date: 3 months ago
config: i386-randconfig-i011-20230817 (https://download.01.org/0day-ci/archive/20230817/202308171419.RgHfW1sc-lkp@xxxxxxxxx/config)
compiler: gcc-11 (Debian 11.3.0-12) 11.3.0
reproduce: (https://download.01.org/0day-ci/archive/20230817/202308171419.RgHfW1sc-lkp@xxxxxxxxx/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@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202308171419.RgHfW1sc-lkp@xxxxxxxxx/

All warnings (new ones prefixed by >>):

arch/x86/kernel/cpu/mtrr/generic.c:125: warning: Function parameter or member 'start' not described in 'mtrr_type_lookup_fixed'
arch/x86/kernel/cpu/mtrr/generic.c:125: warning: Function parameter or member 'end' not described in 'mtrr_type_lookup_fixed'
arch/x86/kernel/cpu/mtrr/generic.c:166: warning: Function parameter or member 'start' not described in 'mtrr_type_lookup_variable'
arch/x86/kernel/cpu/mtrr/generic.c:166: warning: Function parameter or member 'end' not described in 'mtrr_type_lookup_variable'
arch/x86/kernel/cpu/mtrr/generic.c:166: warning: Function parameter or member 'partial_end' not described in 'mtrr_type_lookup_variable'
arch/x86/kernel/cpu/mtrr/generic.c:166: warning: Function parameter or member 'repeat' not described in 'mtrr_type_lookup_variable'
arch/x86/kernel/cpu/mtrr/generic.c:166: warning: Function parameter or member 'uniform' not described in 'mtrr_type_lookup_variable'
>> arch/x86/kernel/cpu/mtrr/generic.c:259: warning: Function parameter or member 'var' not described in 'mtrr_overwrite_state'
>> arch/x86/kernel/cpu/mtrr/generic.c:259: warning: Function parameter or member 'num_var' not described in 'mtrr_overwrite_state'
>> arch/x86/kernel/cpu/mtrr/generic.c:259: warning: Function parameter or member 'def_type' not described in 'mtrr_overwrite_state'
arch/x86/kernel/cpu/mtrr/generic.c:316: warning: Function parameter or member 'start' not described in 'mtrr_type_lookup'
arch/x86/kernel/cpu/mtrr/generic.c:316: warning: Function parameter or member 'end' not described in 'mtrr_type_lookup'
arch/x86/kernel/cpu/mtrr/generic.c:316: warning: Function parameter or member 'uniform' not described in 'mtrr_type_lookup'


vim +259 arch/x86/kernel/cpu/mtrr/generic.c

246
247 /**
248 * mtrr_overwrite_state - set static MTRR state
249 *
250 * Used to set MTRR state via different means (e.g. with data obtained from
251 * a hypervisor).
252 * Is allowed only for special cases when running virtualized. Must be called
253 * from the x86_init.hyper.init_platform() hook. It can be called only once.
254 * The MTRR state can't be changed afterwards. To ensure that, X86_FEATURE_MTRR
255 * is cleared.
256 */
257 void mtrr_overwrite_state(struct mtrr_var_range *var, unsigned int num_var,
258 mtrr_type def_type)
> 259 {
260 unsigned int i;
261
262 /* Only allowed to be called once before mtrr_bp_init(). */
263 if (WARN_ON_ONCE(mtrr_state_set))
264 return;
265
266 /* Only allowed when running virtualized. */
267 if (!cpu_feature_enabled(X86_FEATURE_HYPERVISOR))
268 return;
269
270 /*
271 * Only allowed for special virtualization cases:
272 * - when running as Hyper-V, SEV-SNP guest using vTOM
273 * - when running as Xen PV guest
274 * - when running as SEV-SNP or TDX guest to avoid unnecessary
275 * VMM communication/Virtualization exceptions (#VC, #VE)
276 */
277 if (!cc_platform_has(CC_ATTR_GUEST_SEV_SNP) &&
278 !hv_is_isolation_supported() &&
279 !cpu_feature_enabled(X86_FEATURE_XENPV) &&
280 !cpu_feature_enabled(X86_FEATURE_TDX_GUEST))
281 return;
282
283 /* Disable MTRR in order to disable MTRR modifications. */
284 setup_clear_cpu_cap(X86_FEATURE_MTRR);
285
286 if (var) {
287 if (num_var > MTRR_MAX_VAR_RANGES) {
288 pr_warn("Trying to overwrite MTRR state with %u variable entries\n",
289 num_var);
290 num_var = MTRR_MAX_VAR_RANGES;
291 }
292 for (i = 0; i < num_var; i++)
293 mtrr_state.var_ranges[i] = var[i];
294 num_var_ranges = num_var;
295 }
296
297 mtrr_state.def_type = def_type;
298 mtrr_state.enabled |= MTRR_STATE_MTRR_ENABLED;
299
300 mtrr_state_set = 1;
301 }
302

--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki