1 /* SPDX-License-Identifier: GPL-2.0-only */ 2 /* Copyright(c) 2022 Intel Corporation. */ 3 4 #ifndef _IFS_H_ 5 #define _IFS_H_ 6 7 /** 8 * DOC: In-Field Scan 9 * 10 * ============= 11 * In-Field Scan 12 * ============= 13 * 14 * Introduction 15 * ------------ 16 * 17 * In Field Scan (IFS) is a hardware feature to run circuit level tests on 18 * a CPU core to detect problems that are not caught by parity or ECC checks. 19 * Future CPUs will support more than one type of test which will show up 20 * with a new platform-device instance-id. 21 * 22 * 23 * IFS Image 24 * --------- 25 * 26 * Intel provides a firmware file containing the scan tests via 27 * github [#f1]_. Similar to microcode there is a separate file for each 28 * family-model-stepping. IFS Images are not applicable for some test types. 29 * Wherever applicable the sysfs directory would provide a "current_batch" file 30 * (see below) for loading the image. 31 * 32 * 33 * IFS Image Loading 34 * ----------------- 35 * 36 * The driver loads the tests into memory reserved BIOS local to each CPU 37 * socket in a two step process using writes to MSRs to first load the 38 * SHA hashes for the test. Then the tests themselves. Status MSRs provide 39 * feedback on the success/failure of these steps. 40 * 41 * The test files are kept in a fixed location: /lib/firmware/intel/ifs_<n>/ 42 * For e.g if there are 3 test files, they would be named in the following 43 * fashion: 44 * ff-mm-ss-01.scan 45 * ff-mm-ss-02.scan 46 * ff-mm-ss-03.scan 47 * (where ff refers to family, mm indicates model and ss indicates stepping) 48 * 49 * A different test file can be loaded by writing the numerical portion 50 * (e.g 1, 2 or 3 in the above scenario) into the curent_batch file. 51 * To load ff-mm-ss-02.scan, the following command can be used:: 52 * 53 * # echo 2 > /sys/devices/virtual/misc/intel_ifs_<n>/current_batch 54 * 55 * The above file can also be read to know the currently loaded image. 56 * 57 * Running tests 58 * ------------- 59 * 60 * Tests are run by the driver synchronizing execution of all threads on a 61 * core and then writing to the ACTIVATE_SCAN MSR on all threads. Instruction 62 * execution continues when: 63 * 64 * 1) All tests have completed. 65 * 2) Execution was interrupted. 66 * 3) A test detected a problem. 67 * 68 * Note that ALL THREADS ON THE CORE ARE EFFECTIVELY OFFLINE FOR THE 69 * DURATION OF THE TEST. This can be up to 200 milliseconds. If the system 70 * is running latency sensitive applications that cannot tolerate an 71 * interruption of this magnitude, the system administrator must arrange 72 * to migrate those applications to other cores before running a core test. 73 * It may also be necessary to redirect interrupts to other CPUs. 74 * 75 * In all cases reading the corresponding test's STATUS MSR provides details on what 76 * happened. The driver makes the value of this MSR visible to applications 77 * via the "details" file (see below). Interrupted tests may be restarted. 78 * 79 * The IFS driver provides sysfs interfaces via /sys/devices/virtual/misc/intel_ifs_<n>/ 80 * to control execution: 81 * 82 * Test a specific core:: 83 * 84 * # echo <cpu#> > /sys/devices/virtual/misc/intel_ifs_<n>/run_test 85 * 86 * when HT is enabled any of the sibling cpu# can be specified to test 87 * its corresponding physical core. Since the tests are per physical core, 88 * the result of testing any thread is same. All siblings must be online 89 * to run a core test. It is only necessary to test one thread. 90 * 91 * For e.g. to test core corresponding to cpu5 92 * 93 * # echo 5 > /sys/devices/virtual/misc/intel_ifs_<n>/run_test 94 * 95 * Results of the last test is provided in /sys:: 96 * 97 * $ cat /sys/devices/virtual/misc/intel_ifs_<n>/status 98 * pass 99 * 100 * Status can be one of pass, fail, untested 101 * 102 * Additional details of the last test is provided by the details file:: 103 * 104 * $ cat /sys/devices/virtual/misc/intel_ifs_<n>/details 105 * 0x8081 106 * 107 * The details file reports the hex value of the test specific status MSR. 108 * Hardware defined error codes are documented in volume 4 of the Intel 109 * Software Developer's Manual but the error_code field may contain one of 110 * the following driver defined software codes: 111 * 112 * +------+--------------------+ 113 * | 0xFD | Software timeout | 114 * +------+--------------------+ 115 * | 0xFE | Partial completion | 116 * +------+--------------------+ 117 * 118 * Driver design choices 119 * --------------------- 120 * 121 * 1) The ACTIVATE_SCAN MSR allows for running any consecutive subrange of 122 * available tests. But the driver always tries to run all tests and only 123 * uses the subrange feature to restart an interrupted test. 124 * 125 * 2) Hardware allows for some number of cores to be tested in parallel. 126 * The driver does not make use of this, it only tests one core at a time. 127 * 128 * .. [#f1] https://github.com/intel/TBD 129 */ 130 #include <linux/device.h> 131 #include <linux/miscdevice.h> 132 133 #define MSR_ARRAY_BIST 0x00000105 134 #define MSR_COPY_SCAN_HASHES 0x000002c2 135 #define MSR_SCAN_HASHES_STATUS 0x000002c3 136 #define MSR_AUTHENTICATE_AND_COPY_CHUNK 0x000002c4 137 #define MSR_CHUNKS_AUTHENTICATION_STATUS 0x000002c5 138 #define MSR_ACTIVATE_SCAN 0x000002c6 139 #define MSR_SCAN_STATUS 0x000002c7 140 #define SCAN_NOT_TESTED 0 141 #define SCAN_TEST_PASS 1 142 #define SCAN_TEST_FAIL 2 143 144 #define IFS_TYPE_SAF 0 145 #define IFS_TYPE_ARRAY_BIST 1 146 147 /* MSR_SCAN_HASHES_STATUS bit fields */ 148 union ifs_scan_hashes_status { 149 u64 data; 150 struct { 151 u32 chunk_size :16; 152 u32 num_chunks :8; 153 u32 rsvd1 :8; 154 u32 error_code :8; 155 u32 rsvd2 :11; 156 u32 max_core_limit :12; 157 u32 valid :1; 158 }; 159 }; 160 161 /* MSR_CHUNKS_AUTH_STATUS bit fields */ 162 union ifs_chunks_auth_status { 163 u64 data; 164 struct { 165 u32 valid_chunks :8; 166 u32 total_chunks :8; 167 u32 rsvd1 :16; 168 u32 error_code :8; 169 u32 rsvd2 :24; 170 }; 171 }; 172 173 /* MSR_ACTIVATE_SCAN bit fields */ 174 union ifs_scan { 175 u64 data; 176 struct { 177 u32 start :8; 178 u32 stop :8; 179 u32 rsvd :16; 180 u32 delay :31; 181 u32 sigmce :1; 182 }; 183 }; 184 185 /* MSR_SCAN_STATUS bit fields */ 186 union ifs_status { 187 u64 data; 188 struct { 189 u32 chunk_num :8; 190 u32 chunk_stop_index :8; 191 u32 rsvd1 :16; 192 u32 error_code :8; 193 u32 rsvd2 :22; 194 u32 control_error :1; 195 u32 signature_error :1; 196 }; 197 }; 198 199 /* MSR_ARRAY_BIST bit fields */ 200 union ifs_array { 201 u64 data; 202 struct { 203 u32 array_bitmask; 204 u16 array_bank; 205 u16 rsvd :15; 206 u16 ctrl_result :1; 207 }; 208 }; 209 210 /* 211 * Driver populated error-codes 212 * 0xFD: Test timed out before completing all the chunks. 213 * 0xFE: not all scan chunks were executed. Maximum forward progress retries exceeded. 214 */ 215 #define IFS_SW_TIMEOUT 0xFD 216 #define IFS_SW_PARTIAL_COMPLETION 0xFE 217 218 struct ifs_test_caps { 219 int integrity_cap_bit; 220 int test_num; 221 }; 222 223 /** 224 * struct ifs_data - attributes related to intel IFS driver 225 * @loaded_version: stores the currently loaded ifs image version. 226 * @loaded: If a valid test binary has been loaded into the memory 227 * @loading_error: Error occurred on another CPU while loading image 228 * @valid_chunks: number of chunks which could be validated. 229 * @status: it holds simple status pass/fail/untested 230 * @scan_details: opaque scan status code from h/w 231 * @cur_batch: number indicating the currently loaded test file 232 */ 233 struct ifs_data { 234 int loaded_version; 235 bool loaded; 236 bool loading_error; 237 int valid_chunks; 238 int status; 239 u64 scan_details; 240 u32 cur_batch; 241 }; 242 243 struct ifs_work { 244 struct work_struct w; 245 struct device *dev; 246 }; 247 248 struct ifs_device { 249 const struct ifs_test_caps *test_caps; 250 struct ifs_data rw_data; 251 struct miscdevice misc; 252 }; 253 254 static inline struct ifs_data *ifs_get_data(struct device *dev) 255 { 256 struct miscdevice *m = dev_get_drvdata(dev); 257 struct ifs_device *d = container_of(m, struct ifs_device, misc); 258 259 return &d->rw_data; 260 } 261 262 static inline const struct ifs_test_caps *ifs_get_test_caps(struct device *dev) 263 { 264 struct miscdevice *m = dev_get_drvdata(dev); 265 struct ifs_device *d = container_of(m, struct ifs_device, misc); 266 267 return d->test_caps; 268 } 269 270 extern bool *ifs_pkg_auth; 271 int ifs_load_firmware(struct device *dev); 272 int do_core_test(int cpu, struct device *dev); 273 extern struct attribute *plat_ifs_attrs[]; 274 extern struct attribute *plat_ifs_array_attrs[]; 275 276 #endif 277