// SPDX-License-Identifier: GPL-2.0-only
/* Copyright(c) 2022 Intel Corporation. */
#include <linux/cpu.h>
#include <linux/delay.h>
#include <linux/fs.h>
#include <linux/nmi.h>
#include <linux/slab.h>
#include <linux/stop_machine.h>
#include "ifs.h"
/*
* Note all code and data in this file is protected by
* ifs_sem. On HT systems all threads on a core will
* execute together, but only the first thread on the
* core will update results of the test.
*/
#define CREATE_TRACE_POINTS
#include <trace/events/intel_ifs.h>
/* Max retries on the same chunk */
#define MAX_IFS_RETRIES 5
struct run_params {
struct ifs_data *ifsd;
union ifs_scan *activate;
union ifs_status status;
};
struct sbaf_run_params {
struct ifs_data *ifsd;
int *retry_cnt;
union ifs_sbaf *activate;
union ifs_sbaf_status status;
};
/*
* Number of TSC cycles that a logical CPU will wait for the other
* logical CPU on the core in the WRMSR(ACTIVATE_SCAN).
*/
#define IFS_THREAD_WAIT 100000
enum ifs_status_err_code {
IFS_NO_ERROR = 0,
IFS_OTHER_THREAD_COULD_NOT_JOIN = 1,
IFS_INTERRUPTED_BEFORE_RENDEZVOUS = 2,
IFS_POWER_MGMT_INADEQUATE_FOR_SCAN = 3,
IFS_INVALID_CHUNK_RANGE = 4,
IFS_MISMATCH_ARGUMENTS_BETWEEN_THREADS = 5,
IFS_CORE_NOT_CAPABLE_CURRENTLY = 6,
IFS_UNASSIGNED_ERROR_CODE = 7,
IFS_EXCEED_NUMBER_OF_THREADS_CONCURRENT = 8,
IFS_INTERRUPTED_DURING_EXECUTION = 9,
IFS_UNASSIGNED_ERROR_CODE_0xA = 0xA,
IFS_CORRUPTED_CHUNK = 0xB,
};
static const char * const scan_test_status[] = {
[IFS_NO_ERROR] = "SCAN no error",
[IFS_OTHER_THREAD_COULD_NOT_JOIN] = "Other thread could not join.",
[IFS_INTERRUPTED_BEFORE_RENDEZVOUS] = "Interrupt occurred prior to SCAN coordination.",
[IFS_POWER_MGMT_INADEQUATE_FOR_SCAN] =
"Core Abort SCAN Response due to power management condition.",
[IFS_INVALID_CHUNK_RANGE] = "Non valid chunks in the range",
[IFS_MISMATCH_ARGUMENTS_BETWEEN_THREADS] = "Mismatch in arguments between threads T0/T1.",
[IFS_CORE_NOT_CAPABLE_CURRENTLY] = "Core not capable of performing SCAN currently",
[IFS_UNASSIGNED_ERROR_CODE] = "Unassigned error code 0x7",
[IFS_EXCEED_NUMBER_OF_THREADS_CONCURRENT] =
"Exceeded number of Logical Processors (LP) allowed to run Scan-At-Field concurrently",
[IFS_INTERRUPTED_DURING_EXECUTION] = "Interrupt occurred prior to SCAN start",
[IFS_UNASSIGNED_ERROR_CODE_0xA] = "Unassigned error code 0xA",
[IFS_CORRUPTED_CHUNK] = "Scan operation aborted due to corrupted image. Try reloading",
};
static void message_not_tested(struct device *dev, int cpu, union ifs_status status)
{
struct ifs_data *ifsd = ifs_get_data(dev);
/*
* control_error is set when the microcode runs into a problem
* loading the image from the reserved BIOS memory, or it has
* been corrupted. Reloading the image may fix this issue.
*/
if (status.control_error) {
dev_warn(dev, "CPU(s) %*pbl: Scan controller error. Batch: %02x version: 0x%x\n",
cpumask_pr_args(cpu_smt_mask(cpu)), ifsd->cur_batch, ifsd->loaded_version);
return;
}
if (status.error_code < ARRAY_SIZE(scan_test_status)) {
dev_info(dev, "CPU(s) %*pbl: SCAN operation did not start. %s\n",
cpumask_pr_args(cpu_smt_mask(cpu)),
scan_test_status[status.error_code]);
} else if (status.error_code == IFS_SW_TIMEOUT) {
dev_info(dev, "CPU(s) %*pbl: software timeout during scan\n",
cpumask_pr_args(cpu_smt_mask(cpu)));
} else if (status.error_code == IFS_SW_PARTIAL_COMPLETION) {
dev_info(dev, "CPU(s) %*pbl: %s\n",
cpumask_pr_args(cpu_smt_mask(cpu)),
"Not all scan chunks were executed. Maximum forward progress retries exceeded");
} else {
dev_info(dev, "CPU(s) %*pbl: SCAN unknown status %llx\n",
cpumask_pr_args(cpu_smt_mask(cpu)), status.data);
}
}
static void message_fail(struct device *dev, int cpu, union ifs_status status)
{
struct ifs_data *ifsd = ifs_get_data(dev);
/*
* signature_error is set when the output from the scan chains does not
* match the expected signature. This might be a transient problem (e.g.
* due to a bit flip from an alpha particle or neutron). If the problem
* repeats on a subsequent test, then it indicates an actual problem in
* the core being tested.
*/
if (status.signature_error) {
dev_err(dev, "CPU(s) %*pbl: test signature incorrect. Batch: %02x version: 0x%x\n",
cpumask_pr_args(cpu_smt_mask(cpu)), ifsd->cur_batch, ifsd->loaded_version);
}
}
static bool can_restart(union ifs_status status)
{
enum ifs_status_err_code err_code = status.error_code;
/* Signature for chunk is bad, or scan test failed */
if (status.signature_error || status.control_error)
return false;
switch (err_code) {
case IFS_NO_ERROR:
case IFS_OTHER_THREAD_COULD_NOT_JOIN:
case IFS_INTERRUPTED_BEFORE_RENDEZVOUS:
case IFS_POWER_MGMT_INADEQUATE_FOR_SCAN:
case IFS_EXCEED_NUMBER_OF_THREADS_CONCURRENT:
case IFS_INTERRUPTED_DURING_EXECUTION:
return true;
case IFS_INVALID_CHUNK_RANGE:
case IFS_MISMATCH_ARGUMENTS_BETWEEN_THREADS:
case IFS_CORE_NOT_CAPABLE_CURRENTLY:
case IFS_UNASSIGNED_ERROR_CODE:
case IFS_UNASSIGNED_ERROR_CODE_0xA:
case IFS_CORRUPTED_CHUNK:
break;
}
return false;
}
#define SPINUNIT 100 /* 100 nsec */
static atomic_t array_cpus_in;
static atomic_t scan_cpus_in;
static atomic_t sbaf_cpus_in;
/*
* Simplified cpu sibling rendezvous loop based on microcode loader __wait_for_cpus()
*/
static void wait_for_sibling_cpu(atomic_t *t, long long timeout)
{
int cpu = smp_processor_id();
const struct cpumask *smt_mask = cpu_smt_mask(cpu);
int all_cpus = cpumask_weight(smt_mask);
atomic_inc(t);
while (atomic_read(t) < all_cpus) {
if (timeout < SPINUNIT)
return;
ndelay(SPINUNIT);
timeout -= SPINUNIT;
touch_nmi_watchdog();
}
}
/*
* Execute the scan. Called "simultaneously" on all threads of a core
* at high priority using the stop_cpus mechanism.
*/
static int doscan(void *data)
{
int cpu = smp_processor_id(), start, stop;
struct run_params *params = data;
union ifs_status status;
struct ifs_data *ifsd;
int first;
ifsd = params->ifsd;
if (ifsd->generation) {
start = params->activate->gen2.start;
stop = params->activate->gen2.stop;
} else {
start = params->activate->gen0.start;
stop = params->activate->gen0.stop;
}
/* Only the first logical CPU on a core reports result */
first = cpumask_first(cpu_smt_mask(cpu));
wait_for_sibling_cpu(&scan_cpus_in, NSEC_PER_SEC);
/*
* This WRMSR will wait for other HT threads to also write
* to this MSR (at most for activate.delay cycles). Then it
* starts scan of each requested chunk. The core scan happens
* during the "execution" of the WRMSR. This instruction can
* take up to 200 milliseconds (in the case where all chunks
* are processed in a single pass) before it retires.
*/
wrmsrl(MSR_ACTIVATE_SCAN, params->activate->data);
rdmsrl(MSR_SCAN_STATUS, status.data);
trace_ifs_status(ifsd->cur_batch, start, stop, status.data);
/* Pass back the result of the scan */
if (cpu == first)
params->status = status;
return 0;
}
/*
* Use stop_core_cpuslocked() to synchronize writing to MSR_ACTIVATE_SCAN
* on all threads of the core to be tested. Loop if necessary to complete
* run of all chunks. Include some defensive tests to make sure forward
* progress is made, and that the whole test completes in a reasonable time.
*/
static void ifs_test_core(int cpu, struct device *dev)
{
union ifs_status status = {};
union ifs_scan activate;
unsigned long timeout;
struct ifs_data *ifsd;
int to_start, to_stop;
int status_chunk;
struct run_params params;
int retries;
ifsd = ifs_get_data(dev);
activate.gen0.rsvd = 0;
activate.delay = IFS_THREAD_WAIT;
activate.sigmce = 0;
to_start = 0;
to_stop = ifsd->valid_chunks - 1;
params.ifsd = ifs_get_data(dev);
if (ifsd->generation) {
activate.gen2.start = to_start;
activate.gen2.stop = to_stop;
} else {
activate.gen0.start = to_start;
activate.gen0.stop = to_stop;
}
timeout = jiffies + HZ / 2;
retries = MAX_IFS_RETRIES;
while (to_start <= to_stop) {
if (time_after(jiffies, timeout)) {
status.error_code = IFS_SW_TIMEOUT;
break;
}
params.activate = &activate;
atomic_set(&scan_cpus_in, 0);
stop_core_cpuslocked(cpu, doscan, ¶ms);
status = params.status;
/* Some cases can be retried, give up for others */
if (!can_restart(status))
break;
status_chunk = ifsd->generation ? status.gen2.chunk_num : status.gen0.chunk_num;
if (status_chunk == to_start) {
/* Check for forward progress */
if (--retries == 0) {
if (status.error_code == IFS_NO_ERROR)
status.error_code = IFS_SW_PARTIAL_COMPLETION;
break;
}
} else {
retries = MAX_IFS_RETRIES;
if (ifsd->generation)
activate.gen2.start = status_chunk;
else
activate.gen0.start = status_chunk;
to_start = status_chunk;
}
}
/* Update status for this core */
ifsd->scan_details = status.data;
if (status.signature_error) {
ifsd->status = SCAN_TEST_FAIL;
message_fail(dev, cpu, status);
} else if (status.control_error || status.error_code) {
ifsd->status = SCAN_NOT_TESTED;
message_not_tested(dev, cpu, status);
} else {
ifsd->status = SCAN_TEST_PASS;
}
}
static int do_array_test(void *data)
{
union ifs_array *command = data;
int cpu = smp_processor_id();
int first;
wait_for_sibling_cpu(&array_cpus_in, NSEC_PER_SEC);
/*
* Only one logical CPU on a core needs to trigger the Array test via MSR write.
*/
first = cpumask_first(cpu_smt_mask(cpu));
if (cpu == first) {
wrmsrl(MSR_ARRAY_BIST, command->data);
/* Pass back the result of the test */
rdmsrl(MSR_ARRAY_BIST, command->data);
}
return 0;
}
static void ifs_array_test_core(int cpu, struct device *dev)
{
union ifs_array command = {};
bool timed_out = false;
struct ifs_data *ifsd;
unsigned long timeout;
ifsd = ifs_get_data(dev);
command.array_bitmask = ~0U;
timeout = jiffies + HZ / 2;
do {
if (time_after(jiffies, timeout)) {
timed_out = true;
break;
}
atomic_set(&array_cpus_in, 0);
stop_core_cpuslocked(cpu, do_array_test, &command);
if (command.ctrl_result)
break;
} while (command.array_bitmask);
ifsd->scan_details = command.data;
if (command.ctrl_result)
ifsd->status = SCAN_TEST_FAIL;
else if (timed_out || command.array_bitmask)
ifsd->status = SCAN_NOT_TESTED;
else
ifsd->status = SCAN_TEST_PASS;
}
#define ARRAY_GEN1_TEST_ALL_ARRAYS 0x0ULL
#define ARRAY_GEN1_STATUS_FAIL 0x1ULL
static int do_array_test_gen1(void *status)
{
int cpu = smp_processor_id();
int first;
first = cpumask_first(cpu_smt_mask(cpu));
if (cpu == first) {
wrmsrl(MSR_ARRAY_TRIGGER, ARRAY_GEN1_TEST_ALL_ARRAYS);
rdmsrl(MSR_ARRAY_STATUS, *((u64 *)status));
}
return 0;
}
static void ifs_array_test_gen1(int cpu, struct device *dev)
{
struct ifs_data *ifsd = ifs_get_data(dev);
u64 status = 0;
stop_core_cpuslocked(cpu, do_array_test_gen1, &status);
ifsd->scan_details = status;
if (status & ARRAY_GEN1_STATUS_FAIL)
ifsd->status = SCAN_TEST_FAIL;
else
ifsd->status = SCAN_TEST_PASS;
}
#define SBAF_STATUS_PASS 0
#define SBAF_STATUS_SIGN_FAIL 1
#define SBAF_STATUS_INTR 2
#define SBAF_STATUS_TEST_FAIL 3
enum sbaf_status_err_code {
IFS_SBAF_NO_ERROR = 0,
IFS_SBAF_OTHER_THREAD_COULD_NOT_JOIN = 1,
IFS_SBAF_INTERRUPTED_BEFORE_RENDEZVOUS = 2,
IFS_SBAF_UNASSIGNED_ERROR_CODE3 = 3,
IFS_SBAF_INVALID_BUNDLE_INDEX = 4,
IFS_SBAF_MISMATCH_ARGS_BETWEEN_THREADS = 5,
IFS_SBAF_CORE_NOT_CAPABLE_CURRENTLY = 6,
IFS_SBAF_UNASSIGNED_ERROR_CODE7 = 7,
IFS_SBAF_EXCEED_NUMBER_OF_THREADS_CONCURRENT = 8,
IFS_SBAF_INTERRUPTED_DURING_EXECUTION = 9,
IFS_SBAF_INVALID_PROGRAM_INDEX = 0xA,
IFS_SBAF_CORRUPTED_CHUNK = 0xB,
IFS_SBAF_DID_NOT_START = 0xC,
};
static const char * const sbaf_test_status[] = {
[IFS_SBAF_NO_ERROR] = "SBAF no error",
[IFS_SBAF_OTHER_THREAD_COULD_NOT_JOIN] = "Other thread could not join.",
[IFS_SBAF_INTERRUPTED_BEFORE_RENDEZVOUS] = "Interrupt occurred prior to SBAF coordination.",
[IFS_SBAF_UNASSIGNED_ERROR_CODE3] = "Unassigned error code 0x3",
[IFS_SBAF_INVALID_BUNDLE_INDEX] = "Non-valid sbaf bundles. Reload test image",
[IFS_SBAF_MISMATCH_ARGS_BETWEEN_THREADS] = "Mismatch in arguments between threads T0/T1.",
[IFS_SBAF_CORE_NOT_CAPABLE_CURRENTLY] = "Core not capable of performing SBAF currently",
[IFS_SBAF_UNASSIGNED_ERROR_CODE7] = "Unassigned error code 0x7",
[IFS_SBAF_EXCEED_NUMBER_OF_THREADS_CONCURRENT] = "Exceeded number of Logical Processors (LP) allowed to run Scan-At-Field concurrently",
[IFS_SBAF_INTERRUPTED_DURING_EXECUTION] = "Interrupt occurred prior to SBAF start",
[IFS_SBAF_INVALID_PROGRAM_INDEX] = "SBAF program index not valid",
[IFS_SBAF_CORRUPTED_CHUNK] = "SBAF operation aborted due to corrupted chunk",
[IFS_SBAF_DID_NOT_START] = "SBAF operation did not start",
};
static void sbaf_message_not_tested(struct device *dev, int cpu, u64 status_data)
{
union ifs_sbaf_status status = (union ifs_sbaf_status)status_data;
if (status.error_code < ARRAY_SIZE(sbaf_test_status)) {
dev_info(dev, "CPU(s) %*pbl: SBAF operation did not start. %s\n",
cpumask_pr_args(cpu_smt_mask(cpu)),
sbaf_test_status[status.error_code]);
} else if (status.error_code == IFS_SW_TIMEOUT) {
dev_info(dev, "CPU(s) %*pbl: software timeout during scan\n",
cpumask_pr_args(cpu_smt_mask(cpu)));
} else if (status.error_code == IFS_SW_PARTIAL_COMPLETION) {
dev_info(dev, "CPU(s) %*pbl: %s\n",
cpumask_pr_args(cpu_smt_mask(cpu)),
"Not all SBAF bundles executed. Maximum forward progress retries exceeded");
} else {
dev_info(dev, "CPU(s) %*pbl: SBAF unknown status %llx\n",
cpumask_pr_args(cpu_smt_mask(cpu)), status.data);
}
}
static void sbaf_message_fail(struct device *dev, int cpu, union ifs_sbaf_status status)
{
/* Failed signature check is set when SBAF signature did not match the expected value */
if (status.sbaf_status == SBAF_STATUS_SIGN_FAIL) {
dev_err(dev, "CPU(s) %*pbl: Failed signature check\n",
cpumask_pr_args(cpu_smt_mask(cpu)));
}
/* Failed to reach end of test */
if (status.sbaf_status == SBAF_STATUS_TEST_FAIL) {
dev_err(dev, "CPU(s) %*pbl: Failed to complete test\n",
cpumask_pr_args(cpu_smt_mask(cpu)));
}
}
static bool sbaf_bundle_completed(union ifs_sbaf_status status)
{
return !(status.sbaf_status || status.error_code);
}
static bool sbaf_can_restart(union ifs_sbaf_status status)
{
enum sbaf_status_err_code err_code = status.error_code;
/* Signature for chunk is bad, or scan test failed */
if (status.sbaf_status == SBAF_STATUS_SIGN_FAIL ||
status.sbaf_status == SBAF_STATUS_TEST_FAIL)
return false;
switch (err_code) {
case IFS_SBAF_NO_ERROR:
case IFS_SBAF_OTHER_THREAD_COULD_NOT_JOIN:
case IFS_SBAF_INTERRUPTED_BEFORE_RENDEZVOUS:
case IFS_SBAF_EXCEED_NUMBER_OF_THREADS_CONCURRENT:
case IFS_SBAF_INTERRUPTED_DURING_EXECUTION:
return true;
case IFS_SBAF_UNASSIGNED_ERROR_CODE3:
case IFS_SBAF_INVALID_BUNDLE_INDEX:
case IFS_SBAF_MISMATCH_ARGS_BETWEEN_THREADS:
case IFS_SBAF_CORE_NOT_CAPABLE_CURRENTLY:
case IFS_SBAF_UNASSIGNED_ERROR_CODE7:
case IFS_SBAF_INVALID_PROGRAM_INDEX:
case IFS_SBAF_CORRUPTED_CHUNK:
case IFS_SBAF_DID_NOT_START:
break;
}
return false;
}
/*
* Execute the SBAF test. Called "simultaneously" on all threads of a core
* at high priority using the stop_cpus mechanism.
*/
static int dosbaf(void *data)
{
struct sbaf_run_params *run_params = data;
int cpu = smp_processor_id();
union ifs_sbaf_status status;
struct ifs_data *ifsd;
int first;
ifsd = run_params->ifsd;
/* Only the first logical CPU on a core reports result */
first = cpumask_first(cpu_smt_mask(cpu));
wait_for_sibling_cpu(&sbaf_cpus_in, NSEC_PER_SEC);
/*
* This WRMSR will wait for other HT threads to also write
* to this MSR (at most for activate.delay cycles). Then it
* starts scan of each requested bundle. The core test happens
* during the "execution" of the WRMSR.
*/
wrmsrl(MSR_ACTIVATE_SBAF, run_params->activate->data);
rdmsrl(MSR_SBAF_STATUS, status.data);
trace_ifs_sbaf(ifsd->cur_batch, *run_params->activate, status);
/* Pass back the result of the test */
if (cpu == first)
run_params->status = status;
return 0;
}
static void ifs_sbaf_test_core(int cpu, struct device *dev)
{
struct sbaf_run_params run_params;
union ifs_sbaf_status status = {};
union ifs_sbaf activate;
unsigned long timeout;
struct ifs_data *ifsd;
int stop_bundle;
int retries;
ifsd = ifs_get_data(dev);
activate.data = 0;
activate.delay = IFS_THREAD_WAIT;
timeout = jiffies + 2 * HZ;
retries = MAX_IFS_RETRIES;
activate.bundle_idx = 0;
stop_bundle = ifsd->max_bundle;
while (activate.bundle_idx <= stop_bundle) {
if (time_after(jiffies, timeout)) {
status.error_code = IFS_SW_TIMEOUT;
break;
}
atomic_set(&sbaf_cpus_in, 0);
run_params.ifsd = ifsd;
run_params.activate = &activate;
run_params.retry_cnt = &retries;
stop_core_cpuslocked(cpu, dosbaf, &run_params);
status = run_params.status;
if (sbaf_bundle_completed(status)) {
activate.bundle_idx = status.bundle_idx + 1;
activate.pgm_idx = 0;
retries = MAX_IFS_RETRIES;
continue;
}
/* Some cases can be retried, give up for others */
if (!sbaf_can_restart(status))
break;
if (status.pgm_idx == activate.pgm_idx) {
/* If no progress retry */
if (--retries == 0) {
if (status.error_code == IFS_NO_ERROR)
status.error_code = IFS_SW_PARTIAL_COMPLETION;
break;
}
} else {
/* if some progress, more pgms remaining in bundle, reset retries */
retries = MAX_IFS_RETRIES;
activate.bundle_idx = status.bundle_idx;
activate.pgm_idx = status.pgm_idx;
}
}
/* Update status for this core */
ifsd->scan_details = status.data;
if (status.sbaf_status == SBAF_STATUS_SIGN_FAIL ||
status.sbaf_status == SBAF_STATUS_TEST_FAIL) {
ifsd->status = SCAN_TEST_FAIL;
sbaf_message_fail(dev, cpu, status);
} else if (status.error_code || status.sbaf_status == SBAF_STATUS_INTR ||
(activate.bundle_idx < stop_bundle)) {
ifsd->status = SCAN_NOT_TESTED;
sbaf_message_not_tested(dev, cpu, status.data);
} else {
ifsd->status = SCAN_TEST_PASS;
}
}
/*
* Initiate per core test. It wakes up work queue threads on the target cpu and
* its sibling cpu. Once all sibling threads wake up, the scan test gets executed and
* wait for all sibling threads to finish the scan test.
*/
int do_core_test(int cpu, struct device *dev)
{
const struct ifs_test_caps *test = ifs_get_test_caps(dev);
struct ifs_data *ifsd = ifs_get_data(dev);
int ret = 0;
/* Prevent CPUs from being taken offline during the scan test */
cpus_read_lock();
if (!cpu_online(cpu)) {
dev_info(dev, "cannot test on the offline cpu %d\n", cpu);
ret = -EINVAL;
goto out;
}
switch (test->test_num) {
case IFS_TYPE_SAF:
if (!ifsd->loaded)
ret = -EPERM;
else
ifs_test_core(cpu, dev);
break;
case IFS_TYPE_ARRAY_BIST:
if (ifsd->array_gen == ARRAY_GEN0)
ifs_array_test_core(cpu, dev);
else
ifs_array_test_gen1(cpu, dev);
break;
case IFS_TYPE_SBAF:
if (!ifsd->loaded)
ret = -EPERM;
else
ifs_sbaf_test_core(cpu, dev);
break;
default:
ret = -EINVAL;
}
out:
cpus_read_unlock();
return ret;
}
Codebase Browser
linux