1 files changed, 89 insertions, 0 deletions
diff --git a/include/linux/tsm-mr.h b/include/linux/tsm-mr.h
new file mode 100644
index 000000000000..50a521f4ac97
--- /dev/null
+++ b/include/linux/tsm-mr.h
@@ -0,0 +1,89 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+
+#ifndef __TSM_MR_H
+#define __TSM_MR_H
+
+#include <crypto/hash_info.h>
+
+/**
+ * struct tsm_measurement_register - describes an architectural measurement
+ * register (MR)
+ * @mr_name: name of the MR
+ * @mr_value: buffer containing the current value of the MR
+ * @mr_size: size of the MR - typically the digest size of @mr_hash
+ * @mr_flags: bitwise OR of one or more flags, detailed below
+ * @mr_hash: optional hash identifier defined in include/uapi/linux/hash_info.h.
+ *
+ * A CC guest driver encloses an array of this structure in struct
+ * tsm_measurements to detail the measurement facility supported by the
+ * underlying CC hardware.
+ *
+ * @mr_name and @mr_value must stay valid until this structure is no longer in
+ * use.
+ *
+ * @mr_flags is the bitwise-OR of zero or more of the flags below.
+ *
+ * * %TSM_MR_F_READABLE - the sysfs attribute corresponding to this MR is readable.
+ * * %TSM_MR_F_WRITABLE - the sysfs attribute corresponding to this MR is writable.
+ *   The semantics is typically to extend the MR but could vary depending on the
+ *   architecture and the MR.
+ * * %TSM_MR_F_LIVE - this MR's value may differ from the last value written, so
+ *   must be read back from the underlying CC hardware/firmware.
+ * * %TSM_MR_F_RTMR - bitwise-OR of %TSM_MR_F_LIVE and %TSM_MR_F_WRITABLE.
+ * * %TSM_MR_F_NOHASH - this MR does NOT have an associated hash algorithm.
+ *   @mr_hash will be ignored when this flag is set.
+ */
+struct tsm_measurement_register {
+	const char *mr_name;
+	void *mr_value;
+	u32 mr_size;
+	u32 mr_flags;
+	enum hash_algo mr_hash;
+};
+
+#define TSM_MR_F_NOHASH 1
+#define TSM_MR_F_WRITABLE 2
+#define TSM_MR_F_READABLE 4
+#define TSM_MR_F_LIVE 8
+#define TSM_MR_F_RTMR (TSM_MR_F_LIVE | TSM_MR_F_WRITABLE)
+
+#define TSM_MR_(mr, hash)                              \
+	.mr_name = #mr, .mr_size = hash##_DIGEST_SIZE, \
+	.mr_hash = HASH_ALGO_##hash, .mr_flags = TSM_MR_F_READABLE
+
+/**
+ * struct tsm_measurements - defines the CC architecture specific measurement
+ * facility and methods for updating measurement registers (MRs)
+ * @mrs: Array of MR definitions.
+ * @nr_mrs: Number of elements in @mrs.
+ * @refresh: Callback function to load/sync all MRs from TVM hardware/firmware
+ *           into the kernel cache.
+ * @write: Callback function to write to the MR specified by the parameter @mr.
+ *         Typically, writing to an MR extends the input buffer to that MR.
+ *
+ * The @refresh callback is invoked when an MR with %TSM_MR_F_LIVE set is being
+ * read and the cache is stale. It must reload all MRs with %TSM_MR_F_LIVE set.
+ * The function parameter @tm is a pointer pointing back to this structure.
+ *
+ * The @write callback is invoked whenever an MR is being written. It takes two
+ * additional parameters besides @tm:
+ *
+ * * @mr - points to the MR (an element of @tm->mrs) being written.
+ * * @data - contains the bytes to write and whose size is @mr->mr_size.
+ *
+ * Both @refresh and @write should return 0 on success and an appropriate error
+ * code on failure.
+ */
+struct tsm_measurements {
+	const struct tsm_measurement_register *mrs;
+	size_t nr_mrs;
+	int (*refresh)(const struct tsm_measurements *tm);
+	int (*write)(const struct tsm_measurements *tm,
+		     const struct tsm_measurement_register *mr, const u8 *data);
+};
+
+const struct attribute_group *
+tsm_mr_create_attribute_group(const struct tsm_measurements *tm);
+void tsm_mr_free_attribute_group(const struct attribute_group *attr_grp);
+
+#endif