@@ -1,3 +1,3 @@
obj-$(CONFIG_INTEL_IFS) += intel_ifs.o
-intel_ifs-objs := core.o load.o
+intel_ifs-objs := core.o load.o runtest.o
@@ -11,6 +11,11 @@
#define MSR_SCAN_HASHES_STATUS 0x000002c3
#define MSR_AUTHENTICATE_AND_COPY_CHUNK 0x000002c4
#define MSR_CHUNKS_AUTHENTICATION_STATUS 0x000002c5
+#define MSR_ACTIVATE_SCAN 0x000002c6
+#define MSR_SCAN_STATUS 0x000002c7
+#define SCAN_NOT_TESTED 0
+#define SCAN_TEST_PASS 1
+#define SCAN_TEST_FAIL 2
/* MSR_SCAN_HASHES_STATUS bit fields */
union ifs_scan_hashes_status {
@@ -38,6 +43,40 @@ union ifs_chunks_auth_status {
};
};
+/* MSR_ACTIVATE_SCAN bit fields */
+union ifs_scan {
+ u64 data;
+ struct {
+ u32 start :8;
+ u32 stop :8;
+ u32 rsvd :16;
+ u32 delay :31;
+ u32 sigmce :1;
+ };
+};
+
+/* MSR_SCAN_STATUS bit fields */
+union ifs_status {
+ u64 data;
+ struct {
+ u32 chunk_num :8;
+ u32 chunk_stop_index :8;
+ u32 rsvd1 :16;
+ u32 error_code :8;
+ u32 rsvd2 :22;
+ u32 control_error :1;
+ u32 signature_error :1;
+ };
+};
+
+/*
+ * Driver populated error-codes
+ * 0xFD: Test timed out before completing all the chunks.
+ * 0xFE: not all scan chunks were executed. Maximum forward progress retries exceeded.
+ */
+#define IFS_SW_TIMEOUT 0xFD
+#define IFS_SW_PARTIAL_COMPLETION 0xFE
+
/**
* struct ifs_data - attributes related to intel IFS driver
* @integrity_cap_bit: MSR_INTEGRITY_CAPS bit enumerating this test
@@ -45,6 +84,8 @@ union ifs_chunks_auth_status {
* @loaded: If a valid test binary has been loaded into the memory
* @loading_error: Error occurred on another CPU while loading image
* @valid_chunks: number of chunks which could be validated.
+ * @status: it holds simple status pass/fail/untested
+ * @scan_details: opaque scan status code from h/w
*/
struct ifs_data {
int integrity_cap_bit;
@@ -52,6 +93,8 @@ struct ifs_data {
bool loaded;
bool loading_error;
int valid_chunks;
+ int status;
+ u64 scan_details;
};
struct ifs_work {
@@ -73,5 +116,6 @@ static inline struct ifs_data *ifs_get_data(struct device *dev)
}
void ifs_load_firmware(struct device *dev);
+int do_core_test(int cpu, struct device *dev);
#endif
new file mode 100644
@@ -0,0 +1,247 @@
+// 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.
+ */
+
+/* Max retries on the same chunk */
+#define MAX_IFS_RETRIES 5
+
+/*
+ * 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,
+};
+
+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",
+};
+
+static void message_not_tested(struct device *dev, int cpu, union ifs_status status)
+{
+ 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)
+{
+ /*
+ * 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_err(dev, "CPU(s) %*pbl: could not execute from loaded scan image\n",
+ cpumask_pr_args(cpu_smt_mask(cpu)));
+ }
+
+ /*
+ * 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.\n",
+ cpumask_pr_args(cpu_smt_mask(cpu)));
+ }
+}
+
+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:
+ break;
+ }
+ return false;
+}
+
+/*
+ * 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();
+ u64 *msrs = data;
+ int first;
+
+ /* Only the first logical CPU on a core reports result */
+ first = cpumask_first(cpu_smt_mask(cpu));
+
+ /*
+ * 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, msrs[0]);
+
+ if (cpu == first) {
+ /* Pass back the result of the scan */
+ rdmsrl(MSR_SCAN_STATUS, msrs[1]);
+ }
+
+ 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_scan activate;
+ union ifs_status status;
+ unsigned long timeout;
+ struct ifs_data *ifsd;
+ u64 msrvals[2];
+ int retries;
+
+ ifsd = ifs_get_data(dev);
+
+ activate.rsvd = 0;
+ activate.delay = IFS_THREAD_WAIT;
+ activate.sigmce = 0;
+ activate.start = 0;
+ activate.stop = ifsd->valid_chunks - 1;
+
+ timeout = jiffies + HZ / 2;
+ retries = MAX_IFS_RETRIES;
+
+ while (activate.start <= activate.stop) {
+ if (time_after(jiffies, timeout)) {
+ status.error_code = IFS_SW_TIMEOUT;
+ break;
+ }
+
+ msrvals[0] = activate.data;
+ stop_core_cpuslocked(cpu, doscan, msrvals);
+
+ status.data = msrvals[1];
+
+ /* Some cases can be retried, give up for others */
+ if (!can_restart(status))
+ break;
+
+ if (status.chunk_num == activate.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;
+ activate.start = status.chunk_num;
+ }
+ }
+
+ /* Update status for this core */
+ ifsd->scan_details = status.data;
+
+ if (status.control_error || status.signature_error) {
+ ifsd->status = SCAN_TEST_FAIL;
+ message_fail(dev, cpu, status);
+ } else if (status.error_code) {
+ ifsd->status = SCAN_NOT_TESTED;
+ message_not_tested(dev, cpu, status);
+ } 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)
+{
+ 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;
+ }
+
+ ifs_test_core(cpu, dev);
+out:
+ cpus_read_unlock();
+ return ret;
+}