235 lines
6.7 KiB
C
235 lines
6.7 KiB
C
/* 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
|