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1// SPDX-License-Identifier: GPL-2.0-only2/* Copyright(c) 2022 Intel Corporation. */3 4#include <linux/cpu.h>5#include <linux/delay.h>6#include <linux/fs.h>7#include <linux/nmi.h>8#include <linux/slab.h>9#include <linux/stop_machine.h>10 11#include "ifs.h"12 13/*14 * Note all code and data in this file is protected by15 * ifs_sem. On HT systems all threads on a core will16 * execute together, but only the first thread on the17 * core will update results of the test.18 */19 20#define CREATE_TRACE_POINTS21#include <trace/events/intel_ifs.h>22 23/* Max retries on the same chunk */24#define MAX_IFS_RETRIES  525 26struct run_params {27	struct ifs_data *ifsd;28	union ifs_scan *activate;29	union ifs_status status;30};31 32struct sbaf_run_params {33	struct ifs_data *ifsd;34	int *retry_cnt;35	union ifs_sbaf *activate;36	union ifs_sbaf_status status;37};38 39/*40 * Number of TSC cycles that a logical CPU will wait for the other41 * logical CPU on the core in the WRMSR(ACTIVATE_SCAN).42 */43#define IFS_THREAD_WAIT 10000044 45enum ifs_status_err_code {46	IFS_NO_ERROR				= 0,47	IFS_OTHER_THREAD_COULD_NOT_JOIN		= 1,48	IFS_INTERRUPTED_BEFORE_RENDEZVOUS	= 2,49	IFS_POWER_MGMT_INADEQUATE_FOR_SCAN	= 3,50	IFS_INVALID_CHUNK_RANGE			= 4,51	IFS_MISMATCH_ARGUMENTS_BETWEEN_THREADS	= 5,52	IFS_CORE_NOT_CAPABLE_CURRENTLY		= 6,53	IFS_UNASSIGNED_ERROR_CODE		= 7,54	IFS_EXCEED_NUMBER_OF_THREADS_CONCURRENT	= 8,55	IFS_INTERRUPTED_DURING_EXECUTION	= 9,56	IFS_UNASSIGNED_ERROR_CODE_0xA		= 0xA,57	IFS_CORRUPTED_CHUNK		= 0xB,58};59 60static const char * const scan_test_status[] = {61	[IFS_NO_ERROR] = "SCAN no error",62	[IFS_OTHER_THREAD_COULD_NOT_JOIN] = "Other thread could not join.",63	[IFS_INTERRUPTED_BEFORE_RENDEZVOUS] = "Interrupt occurred prior to SCAN coordination.",64	[IFS_POWER_MGMT_INADEQUATE_FOR_SCAN] =65	"Core Abort SCAN Response due to power management condition.",66	[IFS_INVALID_CHUNK_RANGE] = "Non valid chunks in the range",67	[IFS_MISMATCH_ARGUMENTS_BETWEEN_THREADS] = "Mismatch in arguments between threads T0/T1.",68	[IFS_CORE_NOT_CAPABLE_CURRENTLY] = "Core not capable of performing SCAN currently",69	[IFS_UNASSIGNED_ERROR_CODE] = "Unassigned error code 0x7",70	[IFS_EXCEED_NUMBER_OF_THREADS_CONCURRENT] =71	"Exceeded number of Logical Processors (LP) allowed to run Scan-At-Field concurrently",72	[IFS_INTERRUPTED_DURING_EXECUTION] = "Interrupt occurred prior to SCAN start",73	[IFS_UNASSIGNED_ERROR_CODE_0xA] = "Unassigned error code 0xA",74	[IFS_CORRUPTED_CHUNK] = "Scan operation aborted due to corrupted image. Try reloading",75};76 77static void message_not_tested(struct device *dev, int cpu, union ifs_status status)78{79	struct ifs_data *ifsd = ifs_get_data(dev);80 81	/*82	 * control_error is set when the microcode runs into a problem83	 * loading the image from the reserved BIOS memory, or it has84	 * been corrupted. Reloading the image may fix this issue.85	 */86	if (status.control_error) {87		dev_warn(dev, "CPU(s) %*pbl: Scan controller error. Batch: %02x version: 0x%x\n",88			 cpumask_pr_args(cpu_smt_mask(cpu)), ifsd->cur_batch, ifsd->loaded_version);89		return;90	}91 92	if (status.error_code < ARRAY_SIZE(scan_test_status)) {93		dev_info(dev, "CPU(s) %*pbl: SCAN operation did not start. %s\n",94			 cpumask_pr_args(cpu_smt_mask(cpu)),95			 scan_test_status[status.error_code]);96	} else if (status.error_code == IFS_SW_TIMEOUT) {97		dev_info(dev, "CPU(s) %*pbl: software timeout during scan\n",98			 cpumask_pr_args(cpu_smt_mask(cpu)));99	} else if (status.error_code == IFS_SW_PARTIAL_COMPLETION) {100		dev_info(dev, "CPU(s) %*pbl: %s\n",101			 cpumask_pr_args(cpu_smt_mask(cpu)),102			 "Not all scan chunks were executed. Maximum forward progress retries exceeded");103	} else {104		dev_info(dev, "CPU(s) %*pbl: SCAN unknown status %llx\n",105			 cpumask_pr_args(cpu_smt_mask(cpu)), status.data);106	}107}108 109static void message_fail(struct device *dev, int cpu, union ifs_status status)110{111	struct ifs_data *ifsd = ifs_get_data(dev);112 113	/*114	 * signature_error is set when the output from the scan chains does not115	 * match the expected signature. This might be a transient problem (e.g.116	 * due to a bit flip from an alpha particle or neutron). If the problem117	 * repeats on a subsequent test, then it indicates an actual problem in118	 * the core being tested.119	 */120	if (status.signature_error) {121		dev_err(dev, "CPU(s) %*pbl: test signature incorrect. Batch: %02x version: 0x%x\n",122			cpumask_pr_args(cpu_smt_mask(cpu)), ifsd->cur_batch, ifsd->loaded_version);123	}124}125 126static bool can_restart(union ifs_status status)127{128	enum ifs_status_err_code err_code = status.error_code;129 130	/* Signature for chunk is bad, or scan test failed */131	if (status.signature_error || status.control_error)132		return false;133 134	switch (err_code) {135	case IFS_NO_ERROR:136	case IFS_OTHER_THREAD_COULD_NOT_JOIN:137	case IFS_INTERRUPTED_BEFORE_RENDEZVOUS:138	case IFS_POWER_MGMT_INADEQUATE_FOR_SCAN:139	case IFS_EXCEED_NUMBER_OF_THREADS_CONCURRENT:140	case IFS_INTERRUPTED_DURING_EXECUTION:141		return true;142	case IFS_INVALID_CHUNK_RANGE:143	case IFS_MISMATCH_ARGUMENTS_BETWEEN_THREADS:144	case IFS_CORE_NOT_CAPABLE_CURRENTLY:145	case IFS_UNASSIGNED_ERROR_CODE:146	case IFS_UNASSIGNED_ERROR_CODE_0xA:147	case IFS_CORRUPTED_CHUNK:148		break;149	}150	return false;151}152 153#define SPINUNIT 100 /* 100 nsec */154static atomic_t array_cpus_in;155static atomic_t scan_cpus_in;156static atomic_t sbaf_cpus_in;157 158/*159 * Simplified cpu sibling rendezvous loop based on microcode loader __wait_for_cpus()160 */161static void wait_for_sibling_cpu(atomic_t *t, long long timeout)162{163	int cpu = smp_processor_id();164	const struct cpumask *smt_mask = cpu_smt_mask(cpu);165	int all_cpus = cpumask_weight(smt_mask);166 167	atomic_inc(t);168	while (atomic_read(t) < all_cpus) {169		if (timeout < SPINUNIT)170			return;171		ndelay(SPINUNIT);172		timeout -= SPINUNIT;173		touch_nmi_watchdog();174	}175}176 177/*178 * Execute the scan. Called "simultaneously" on all threads of a core179 * at high priority using the stop_cpus mechanism.180 */181static int doscan(void *data)182{183	int cpu = smp_processor_id(), start, stop;184	struct run_params *params = data;185	union ifs_status status;186	struct ifs_data *ifsd;187	int first;188 189	ifsd = params->ifsd;190 191	if (ifsd->generation) {192		start = params->activate->gen2.start;193		stop = params->activate->gen2.stop;194	} else {195		start = params->activate->gen0.start;196		stop = params->activate->gen0.stop;197	}198 199	/* Only the first logical CPU on a core reports result */200	first = cpumask_first(cpu_smt_mask(cpu));201 202	wait_for_sibling_cpu(&scan_cpus_in, NSEC_PER_SEC);203 204	/*205	 * This WRMSR will wait for other HT threads to also write206	 * to this MSR (at most for activate.delay cycles). Then it207	 * starts scan of each requested chunk. The core scan happens208	 * during the "execution" of the WRMSR. This instruction can209	 * take up to 200 milliseconds (in the case where all chunks210	 * are processed in a single pass) before it retires.211	 */212	wrmsrl(MSR_ACTIVATE_SCAN, params->activate->data);213	rdmsrl(MSR_SCAN_STATUS, status.data);214 215	trace_ifs_status(ifsd->cur_batch, start, stop, status.data);216 217	/* Pass back the result of the scan */218	if (cpu == first)219		params->status = status;220 221	return 0;222}223 224/*225 * Use stop_core_cpuslocked() to synchronize writing to MSR_ACTIVATE_SCAN226 * on all threads of the core to be tested. Loop if necessary to complete227 * run of all chunks. Include some defensive tests to make sure forward228 * progress is made, and that the whole test completes in a reasonable time.229 */230static void ifs_test_core(int cpu, struct device *dev)231{232	union ifs_status status = {};233	union ifs_scan activate;234	unsigned long timeout;235	struct ifs_data *ifsd;236	int to_start, to_stop;237	int status_chunk;238	struct run_params params;239	int retries;240 241	ifsd = ifs_get_data(dev);242 243	activate.gen0.rsvd = 0;244	activate.delay = IFS_THREAD_WAIT;245	activate.sigmce = 0;246	to_start = 0;247	to_stop = ifsd->valid_chunks - 1;248 249	params.ifsd = ifs_get_data(dev);250 251	if (ifsd->generation) {252		activate.gen2.start = to_start;253		activate.gen2.stop = to_stop;254	} else {255		activate.gen0.start = to_start;256		activate.gen0.stop = to_stop;257	}258 259	timeout = jiffies + HZ / 2;260	retries = MAX_IFS_RETRIES;261 262	while (to_start <= to_stop) {263		if (time_after(jiffies, timeout)) {264			status.error_code = IFS_SW_TIMEOUT;265			break;266		}267 268		params.activate = &activate;269		atomic_set(&scan_cpus_in, 0);270		stop_core_cpuslocked(cpu, doscan, &params);271 272		status = params.status;273 274		/* Some cases can be retried, give up for others */275		if (!can_restart(status))276			break;277 278		status_chunk = ifsd->generation ? status.gen2.chunk_num : status.gen0.chunk_num;279		if (status_chunk == to_start) {280			/* Check for forward progress */281			if (--retries == 0) {282				if (status.error_code == IFS_NO_ERROR)283					status.error_code = IFS_SW_PARTIAL_COMPLETION;284				break;285			}286		} else {287			retries = MAX_IFS_RETRIES;288			if (ifsd->generation)289				activate.gen2.start = status_chunk;290			else291				activate.gen0.start = status_chunk;292			to_start = status_chunk;293		}294	}295 296	/* Update status for this core */297	ifsd->scan_details = status.data;298 299	if (status.signature_error) {300		ifsd->status = SCAN_TEST_FAIL;301		message_fail(dev, cpu, status);302	} else if (status.control_error || status.error_code) {303		ifsd->status = SCAN_NOT_TESTED;304		message_not_tested(dev, cpu, status);305	} else {306		ifsd->status = SCAN_TEST_PASS;307	}308}309 310static int do_array_test(void *data)311{312	union ifs_array *command = data;313	int cpu = smp_processor_id();314	int first;315 316	wait_for_sibling_cpu(&array_cpus_in, NSEC_PER_SEC);317 318	/*319	 * Only one logical CPU on a core needs to trigger the Array test via MSR write.320	 */321	first = cpumask_first(cpu_smt_mask(cpu));322 323	if (cpu == first) {324		wrmsrl(MSR_ARRAY_BIST, command->data);325		/* Pass back the result of the test */326		rdmsrl(MSR_ARRAY_BIST, command->data);327	}328 329	return 0;330}331 332static void ifs_array_test_core(int cpu, struct device *dev)333{334	union ifs_array command = {};335	bool timed_out = false;336	struct ifs_data *ifsd;337	unsigned long timeout;338 339	ifsd = ifs_get_data(dev);340 341	command.array_bitmask = ~0U;342	timeout = jiffies + HZ / 2;343 344	do {345		if (time_after(jiffies, timeout)) {346			timed_out = true;347			break;348		}349		atomic_set(&array_cpus_in, 0);350		stop_core_cpuslocked(cpu, do_array_test, &command);351 352		if (command.ctrl_result)353			break;354	} while (command.array_bitmask);355 356	ifsd->scan_details = command.data;357 358	if (command.ctrl_result)359		ifsd->status = SCAN_TEST_FAIL;360	else if (timed_out || command.array_bitmask)361		ifsd->status = SCAN_NOT_TESTED;362	else363		ifsd->status = SCAN_TEST_PASS;364}365 366#define ARRAY_GEN1_TEST_ALL_ARRAYS	0x0ULL367#define ARRAY_GEN1_STATUS_FAIL		0x1ULL368 369static int do_array_test_gen1(void *status)370{371	int cpu = smp_processor_id();372	int first;373 374	first = cpumask_first(cpu_smt_mask(cpu));375 376	if (cpu == first) {377		wrmsrl(MSR_ARRAY_TRIGGER, ARRAY_GEN1_TEST_ALL_ARRAYS);378		rdmsrl(MSR_ARRAY_STATUS, *((u64 *)status));379	}380 381	return 0;382}383 384static void ifs_array_test_gen1(int cpu, struct device *dev)385{386	struct ifs_data *ifsd = ifs_get_data(dev);387	u64 status = 0;388 389	stop_core_cpuslocked(cpu, do_array_test_gen1, &status);390	ifsd->scan_details = status;391 392	if (status & ARRAY_GEN1_STATUS_FAIL)393		ifsd->status = SCAN_TEST_FAIL;394	else395		ifsd->status = SCAN_TEST_PASS;396}397 398#define SBAF_STATUS_PASS			0399#define SBAF_STATUS_SIGN_FAIL			1400#define SBAF_STATUS_INTR			2401#define SBAF_STATUS_TEST_FAIL			3402 403enum sbaf_status_err_code {404	IFS_SBAF_NO_ERROR				= 0,405	IFS_SBAF_OTHER_THREAD_COULD_NOT_JOIN		= 1,406	IFS_SBAF_INTERRUPTED_BEFORE_RENDEZVOUS		= 2,407	IFS_SBAF_UNASSIGNED_ERROR_CODE3			= 3,408	IFS_SBAF_INVALID_BUNDLE_INDEX			= 4,409	IFS_SBAF_MISMATCH_ARGS_BETWEEN_THREADS		= 5,410	IFS_SBAF_CORE_NOT_CAPABLE_CURRENTLY		= 6,411	IFS_SBAF_UNASSIGNED_ERROR_CODE7			= 7,412	IFS_SBAF_EXCEED_NUMBER_OF_THREADS_CONCURRENT	= 8,413	IFS_SBAF_INTERRUPTED_DURING_EXECUTION		= 9,414	IFS_SBAF_INVALID_PROGRAM_INDEX			= 0xA,415	IFS_SBAF_CORRUPTED_CHUNK			= 0xB,416	IFS_SBAF_DID_NOT_START				= 0xC,417};418 419static const char * const sbaf_test_status[] = {420	[IFS_SBAF_NO_ERROR] = "SBAF no error",421	[IFS_SBAF_OTHER_THREAD_COULD_NOT_JOIN] = "Other thread could not join.",422	[IFS_SBAF_INTERRUPTED_BEFORE_RENDEZVOUS] = "Interrupt occurred prior to SBAF coordination.",423	[IFS_SBAF_UNASSIGNED_ERROR_CODE3] = "Unassigned error code 0x3",424	[IFS_SBAF_INVALID_BUNDLE_INDEX] = "Non-valid sbaf bundles. Reload test image",425	[IFS_SBAF_MISMATCH_ARGS_BETWEEN_THREADS] = "Mismatch in arguments between threads T0/T1.",426	[IFS_SBAF_CORE_NOT_CAPABLE_CURRENTLY] = "Core not capable of performing SBAF currently",427	[IFS_SBAF_UNASSIGNED_ERROR_CODE7] = "Unassigned error code 0x7",428	[IFS_SBAF_EXCEED_NUMBER_OF_THREADS_CONCURRENT] = "Exceeded number of Logical Processors (LP) allowed to run Scan-At-Field concurrently",429	[IFS_SBAF_INTERRUPTED_DURING_EXECUTION] = "Interrupt occurred prior to SBAF start",430	[IFS_SBAF_INVALID_PROGRAM_INDEX] = "SBAF program index not valid",431	[IFS_SBAF_CORRUPTED_CHUNK] = "SBAF operation aborted due to corrupted chunk",432	[IFS_SBAF_DID_NOT_START] = "SBAF operation did not start",433};434 435static void sbaf_message_not_tested(struct device *dev, int cpu, u64 status_data)436{437	union ifs_sbaf_status status = (union ifs_sbaf_status)status_data;438 439	if (status.error_code < ARRAY_SIZE(sbaf_test_status)) {440		dev_info(dev, "CPU(s) %*pbl: SBAF operation did not start. %s\n",441			 cpumask_pr_args(cpu_smt_mask(cpu)),442			 sbaf_test_status[status.error_code]);443	} else if (status.error_code == IFS_SW_TIMEOUT) {444		dev_info(dev, "CPU(s) %*pbl: software timeout during scan\n",445			 cpumask_pr_args(cpu_smt_mask(cpu)));446	} else if (status.error_code == IFS_SW_PARTIAL_COMPLETION) {447		dev_info(dev, "CPU(s) %*pbl: %s\n",448			 cpumask_pr_args(cpu_smt_mask(cpu)),449			 "Not all SBAF bundles executed. Maximum forward progress retries exceeded");450	} else {451		dev_info(dev, "CPU(s) %*pbl: SBAF unknown status %llx\n",452			 cpumask_pr_args(cpu_smt_mask(cpu)), status.data);453	}454}455 456static void sbaf_message_fail(struct device *dev, int cpu, union ifs_sbaf_status status)457{458	/* Failed signature check is set when SBAF signature did not match the expected value */459	if (status.sbaf_status == SBAF_STATUS_SIGN_FAIL) {460		dev_err(dev, "CPU(s) %*pbl: Failed signature check\n",461			cpumask_pr_args(cpu_smt_mask(cpu)));462	}463 464	/* Failed to reach end of test */465	if (status.sbaf_status == SBAF_STATUS_TEST_FAIL) {466		dev_err(dev, "CPU(s) %*pbl: Failed to complete test\n",467			cpumask_pr_args(cpu_smt_mask(cpu)));468	}469}470 471static bool sbaf_bundle_completed(union ifs_sbaf_status status)472{473	return !(status.sbaf_status || status.error_code);474}475 476static bool sbaf_can_restart(union ifs_sbaf_status status)477{478	enum sbaf_status_err_code err_code = status.error_code;479 480	/* Signature for chunk is bad, or scan test failed */481	if (status.sbaf_status == SBAF_STATUS_SIGN_FAIL ||482	    status.sbaf_status == SBAF_STATUS_TEST_FAIL)483		return false;484 485	switch (err_code) {486	case IFS_SBAF_NO_ERROR:487	case IFS_SBAF_OTHER_THREAD_COULD_NOT_JOIN:488	case IFS_SBAF_INTERRUPTED_BEFORE_RENDEZVOUS:489	case IFS_SBAF_EXCEED_NUMBER_OF_THREADS_CONCURRENT:490	case IFS_SBAF_INTERRUPTED_DURING_EXECUTION:491		return true;492	case IFS_SBAF_UNASSIGNED_ERROR_CODE3:493	case IFS_SBAF_INVALID_BUNDLE_INDEX:494	case IFS_SBAF_MISMATCH_ARGS_BETWEEN_THREADS:495	case IFS_SBAF_CORE_NOT_CAPABLE_CURRENTLY:496	case IFS_SBAF_UNASSIGNED_ERROR_CODE7:497	case IFS_SBAF_INVALID_PROGRAM_INDEX:498	case IFS_SBAF_CORRUPTED_CHUNK:499	case IFS_SBAF_DID_NOT_START:500		break;501	}502	return false;503}504 505/*506 * Execute the SBAF test. Called "simultaneously" on all threads of a core507 * at high priority using the stop_cpus mechanism.508 */509static int dosbaf(void *data)510{511	struct sbaf_run_params *run_params = data;512	int cpu = smp_processor_id();513	union ifs_sbaf_status status;514	struct ifs_data *ifsd;515	int first;516 517	ifsd = run_params->ifsd;518 519	/* Only the first logical CPU on a core reports result */520	first = cpumask_first(cpu_smt_mask(cpu));521	wait_for_sibling_cpu(&sbaf_cpus_in, NSEC_PER_SEC);522 523	/*524	 * This WRMSR will wait for other HT threads to also write525	 * to this MSR (at most for activate.delay cycles). Then it526	 * starts scan of each requested bundle. The core test happens527	 * during the "execution" of the WRMSR.528	 */529	wrmsrl(MSR_ACTIVATE_SBAF, run_params->activate->data);530	rdmsrl(MSR_SBAF_STATUS, status.data);531	trace_ifs_sbaf(ifsd->cur_batch, *run_params->activate, status);532 533	/* Pass back the result of the test */534	if (cpu == first)535		run_params->status = status;536 537	return 0;538}539 540static void ifs_sbaf_test_core(int cpu, struct device *dev)541{542	struct sbaf_run_params run_params;543	union ifs_sbaf_status status = {};544	union ifs_sbaf activate;545	unsigned long timeout;546	struct ifs_data *ifsd;547	int stop_bundle;548	int retries;549 550	ifsd = ifs_get_data(dev);551 552	activate.data = 0;553	activate.delay = IFS_THREAD_WAIT;554 555	timeout = jiffies + 2 * HZ;556	retries = MAX_IFS_RETRIES;557	activate.bundle_idx = 0;558	stop_bundle = ifsd->max_bundle;559 560	while (activate.bundle_idx <= stop_bundle) {561		if (time_after(jiffies, timeout)) {562			status.error_code = IFS_SW_TIMEOUT;563			break;564		}565 566		atomic_set(&sbaf_cpus_in, 0);567 568		run_params.ifsd = ifsd;569		run_params.activate = &activate;570		run_params.retry_cnt = &retries;571		stop_core_cpuslocked(cpu, dosbaf, &run_params);572 573		status = run_params.status;574 575		if (sbaf_bundle_completed(status)) {576			activate.bundle_idx = status.bundle_idx + 1;577			activate.pgm_idx = 0;578			retries = MAX_IFS_RETRIES;579			continue;580		}581 582		/* Some cases can be retried, give up for others */583		if (!sbaf_can_restart(status))584			break;585 586		if (status.pgm_idx == activate.pgm_idx) {587			/* If no progress retry */588			if (--retries == 0) {589				if (status.error_code == IFS_NO_ERROR)590					status.error_code = IFS_SW_PARTIAL_COMPLETION;591				break;592			}593		} else {594			/* if some progress, more pgms remaining in bundle, reset retries */595			retries = MAX_IFS_RETRIES;596			activate.bundle_idx = status.bundle_idx;597			activate.pgm_idx = status.pgm_idx;598		}599	}600 601	/* Update status for this core */602	ifsd->scan_details = status.data;603 604	if (status.sbaf_status == SBAF_STATUS_SIGN_FAIL ||605	    status.sbaf_status == SBAF_STATUS_TEST_FAIL) {606		ifsd->status = SCAN_TEST_FAIL;607		sbaf_message_fail(dev, cpu, status);608	} else if (status.error_code || status.sbaf_status == SBAF_STATUS_INTR ||609		   (activate.bundle_idx < stop_bundle)) {610		ifsd->status = SCAN_NOT_TESTED;611		sbaf_message_not_tested(dev, cpu, status.data);612	} else {613		ifsd->status = SCAN_TEST_PASS;614	}615}616 617/*618 * Initiate per core test. It wakes up work queue threads on the target cpu and619 * its sibling cpu. Once all sibling threads wake up, the scan test gets executed and620 * wait for all sibling threads to finish the scan test.621 */622int do_core_test(int cpu, struct device *dev)623{624	const struct ifs_test_caps *test = ifs_get_test_caps(dev);625	struct ifs_data *ifsd = ifs_get_data(dev);626	int ret = 0;627 628	/* Prevent CPUs from being taken offline during the scan test */629	cpus_read_lock();630 631	if (!cpu_online(cpu)) {632		dev_info(dev, "cannot test on the offline cpu %d\n", cpu);633		ret = -EINVAL;634		goto out;635	}636 637	switch (test->test_num) {638	case IFS_TYPE_SAF:639		if (!ifsd->loaded)640			ret = -EPERM;641		else642			ifs_test_core(cpu, dev);643		break;644	case IFS_TYPE_ARRAY_BIST:645		if (ifsd->array_gen == ARRAY_GEN0)646			ifs_array_test_core(cpu, dev);647		else648			ifs_array_test_gen1(cpu, dev);649		break;650	case IFS_TYPE_SBAF:651		if (!ifsd->loaded)652			ret = -EPERM;653		else654			ifs_sbaf_test_core(cpu, dev);655		break;656	default:657		ret = -EINVAL;658	}659out:660	cpus_read_unlock();661	return ret;662}663