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Diffstat (limited to 'drivers/platform/x86/intel/ifs/ifs.h')
| -rw-r--r-- | drivers/platform/x86/intel/ifs/ifs.h | 234 |
1 files changed, 234 insertions, 0 deletions
diff --git a/drivers/platform/x86/intel/ifs/ifs.h b/drivers/platform/x86/intel/ifs/ifs.h new file mode 100644 index 000000000..73c8e91cf --- /dev/null +++ b/drivers/platform/x86/intel/ifs/ifs.h @@ -0,0 +1,234 @@ +/* SPDX-License-Identifier: GPL-2.0-only */ +/* Copyright(c) 2022 Intel Corporation. */ + +#ifndef _IFS_H_ +#define _IFS_H_ + +/** + * DOC: In-Field Scan + * + * ============= + * In-Field Scan + * ============= + * + * Introduction + * ------------ + * + * In Field Scan (IFS) is a hardware feature to run circuit level tests on + * a CPU core to detect problems that are not caught by parity or ECC checks. + * Future CPUs will support more than one type of test which will show up + * with a new platform-device instance-id, for now only .0 is exposed. + * + * + * IFS Image + * --------- + * + * Intel provides a firmware file containing the scan tests via + * github [#f1]_. Similar to microcode there is a separate file for each + * family-model-stepping. + * + * IFS Image Loading + * ----------------- + * + * The driver loads the tests into memory reserved BIOS local to each CPU + * socket in a two step process using writes to MSRs to first load the + * SHA hashes for the test. Then the tests themselves. Status MSRs provide + * feedback on the success/failure of these steps. When a new test file + * is installed it can be loaded by writing to the driver reload file:: + * + * # echo 1 > /sys/devices/virtual/misc/intel_ifs_0/reload + * + * Similar to microcode, the current version of the scan tests is stored + * in a fixed location: /lib/firmware/intel/ifs.0/family-model-stepping.scan + * + * Running tests + * ------------- + * + * Tests are run by the driver synchronizing execution of all threads on a + * core and then writing to the ACTIVATE_SCAN MSR on all threads. Instruction + * execution continues when: + * + * 1) All tests have completed. + * 2) Execution was interrupted. + * 3) A test detected a problem. + * + * Note that ALL THREADS ON THE CORE ARE EFFECTIVELY OFFLINE FOR THE + * DURATION OF THE TEST. This can be up to 200 milliseconds. If the system + * is running latency sensitive applications that cannot tolerate an + * interruption of this magnitude, the system administrator must arrange + * to migrate those applications to other cores before running a core test. + * It may also be necessary to redirect interrupts to other CPUs. + * + * In all cases reading the SCAN_STATUS MSR provides details on what + * happened. The driver makes the value of this MSR visible to applications + * via the "details" file (see below). Interrupted tests may be restarted. + * + * The IFS driver provides sysfs interfaces via /sys/devices/virtual/misc/intel_ifs_0/ + * to control execution: + * + * Test a specific core:: + * + * # echo <cpu#> > /sys/devices/virtual/misc/intel_ifs_0/run_test + * + * when HT is enabled any of the sibling cpu# can be specified to test + * its corresponding physical core. Since the tests are per physical core, + * the result of testing any thread is same. All siblings must be online + * to run a core test. It is only necessary to test one thread. + * + * For e.g. to test core corresponding to cpu5 + * + * # echo 5 > /sys/devices/virtual/misc/intel_ifs_0/run_test + * + * Results of the last test is provided in /sys:: + * + * $ cat /sys/devices/virtual/misc/intel_ifs_0/status + * pass + * + * Status can be one of pass, fail, untested + * + * Additional details of the last test is provided by the details file:: + * + * $ cat /sys/devices/virtual/misc/intel_ifs_0/details + * 0x8081 + * + * The details file reports the hex value of the SCAN_STATUS MSR. + * Hardware defined error codes are documented in volume 4 of the Intel + * Software Developer's Manual but the error_code field may contain one of + * the following driver defined software codes: + * + * +------+--------------------+ + * | 0xFD | Software timeout | + * +------+--------------------+ + * | 0xFE | Partial completion | + * +------+--------------------+ + * + * Driver design choices + * --------------------- + * + * 1) The ACTIVATE_SCAN MSR allows for running any consecutive subrange of + * available tests. But the driver always tries to run all tests and only + * uses the subrange feature to restart an interrupted test. + * + * 2) Hardware allows for some number of cores to be tested in parallel. + * The driver does not make use of this, it only tests one core at a time. + * + * .. [#f1] https://github.com/intel/TBD + */ +#include <linux/device.h> +#include <linux/miscdevice.h> + +#define MSR_COPY_SCAN_HASHES 0x000002c2 +#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 { + u64 data; + struct { + u32 chunk_size :16; + u32 num_chunks :8; + u32 rsvd1 :8; + u32 error_code :8; + u32 rsvd2 :11; + u32 max_core_limit :12; + u32 valid :1; + }; +}; + +/* MSR_CHUNKS_AUTH_STATUS bit fields */ +union ifs_chunks_auth_status { + u64 data; + struct { + u32 valid_chunks :8; + u32 total_chunks :8; + u32 rsvd1 :16; + u32 error_code :8; + u32 rsvd2 :24; + }; +}; + +/* 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 + * @loaded_version: stores the currently loaded ifs image version. + * @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; + int loaded_version; + bool loaded; + bool loading_error; + int valid_chunks; + int status; + u64 scan_details; +}; + +struct ifs_work { + struct work_struct w; + struct device *dev; +}; + +struct ifs_device { + struct ifs_data data; + struct miscdevice misc; +}; + +static inline struct ifs_data *ifs_get_data(struct device *dev) +{ + struct miscdevice *m = dev_get_drvdata(dev); + struct ifs_device *d = container_of(m, struct ifs_device, misc); + + return &d->data; +} + +void ifs_load_firmware(struct device *dev); +int do_core_test(int cpu, struct device *dev); +const struct attribute_group **ifs_get_groups(void); + +extern struct semaphore ifs_sem; + +#endif |