]> git.dujemihanovic.xyz Git - u-boot.git/commitdiff
tpm: Implement state command for Cr50
authorSimon Glass <sjg@chromium.org>
Wed, 31 Aug 2022 03:05:37 +0000 (21:05 -0600)
committerIlias Apalodimas <ilias.apalodimas@linaro.org>
Sat, 3 Sep 2022 13:59:05 +0000 (16:59 +0300)
Add a vendor-specific TPM2 command for this and implement it for Cr50.
Note: This is not part of the TPM spec, but is a Cr50 extension.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
drivers/tpm/cr50_i2c.c
include/tpm-v2.h
lib/tpm-v2.c

index f8c308789477cef7799229636509c7be95022102..acf4c7859a9fa50afae18de3446bae974f4f1201 100644 (file)
 #include <irq.h>
 #include <log.h>
 #include <spl.h>
+#include <tpm-common.h>
 #include <tpm-v2.h>
 #include <acpi/acpigen.h>
 #include <acpi/acpi_device.h>
 #include <asm/gpio.h>
 #include <asm/io.h>
+#include <asm/unaligned.h>
 #include <linux/delay.h>
 #include <dm/acpi.h>
 
@@ -37,6 +39,50 @@ enum {
        CR50_MAX_BUF_SIZE = 63,
 };
 
+/*
+ * Operations specific to the Cr50 TPM used on Chromium OS and Android devices
+ *
+ * FIXME: below is not enough to differentiate between vendors commands
+ * of numerous devices. However, the current tpm2 APIs aren't very amenable
+ * to extending generically because the marshaling code is assuming all
+ * knowledge of all commands.
+ */
+#define TPM2_CC_VENDOR_BIT_MASK                        0x20000000
+
+#define TPM2_CR50_VENDOR_COMMAND               (TPM2_CC_VENDOR_BIT_MASK | 0)
+#define TPM2_CR50_SUB_CMD_IMMEDIATE_RESET      19
+#define TPM2_CR50_SUB_CMD_NVMEM_ENABLE_COMMITS 21
+#define TPM2_CR50_SUB_CMD_REPORT_TPM_STATE     23
+#define TPM2_CR50_SUB_CMD_TURN_UPDATE_ON       24
+#define TPM2_CR50_SUB_CMD_GET_REC_BTN          29
+#define TPM2_CR50_SUB_CMD_TPM_MODE             40
+#define TPM2_CR50_SUB_CMD_GET_BOOT_MODE                52
+#define TPM2_CR50_SUB_CMD_RESET_EC             53
+
+/* Cr50 vendor-specific error codes. */
+#define VENDOR_RC_ERR              0x00000500
+enum cr50_vendor_rc {
+       VENDOR_RC_INTERNAL_ERROR        = (VENDOR_RC_ERR | 6),
+       VENDOR_RC_NO_SUCH_SUBCOMMAND    = (VENDOR_RC_ERR | 8),
+       VENDOR_RC_NO_SUCH_COMMAND       = (VENDOR_RC_ERR | 127),
+};
+
+enum cr50_tpm_mode {
+       /*
+        * Default state: TPM is enabled, and may be set to either
+        * TPM_MODE_ENABLED or TPM_MODE_DISABLED.
+        */
+       TPM_MODE_ENABLED_TENTATIVE = 0,
+
+       /* TPM is enabled, and mode may not be changed. */
+       TPM_MODE_ENABLED = 1,
+
+       /* TPM is disabled, and mode may not be changed. */
+       TPM_MODE_DISABLED = 2,
+
+       TPM_MODE_INVALID,
+};
+
 /**
  * struct cr50_priv - Private driver data
  *
@@ -54,6 +100,41 @@ struct cr50_priv {
        bool use_irq;
 };
 
+/*
+ * The below structure represents the body of the response to the 'report tpm
+ * state' vendor command.
+ *
+ * It is transferred over the wire, so it needs to be serialized/deserialized,
+ * and it is likely to change, so its contents must be versioned.
+ */
+#define TPM_STATE_VERSION      1
+struct tpm_vendor_state {
+       u32 version;
+       /*
+        * The following three fields are set by the TPM in case of an assert.
+        * There is no other processing than setting the source code line
+        * number, error code and the first 4 characters of the function name.
+        *
+        * We don't expect this happening, but it is included in the report
+        * just in case.
+        */
+       u32 fail_line;  /* s_failLIne */
+       u32 fail_code;  /* s_failCode */
+       char func_name[4];      /* s_failFunction, limited to 4 chars */
+
+       /*
+        * The following two fields are the current time filtered value of the
+        * 'failed tries' TPM counter, and the maximum allowed value of the
+        * counter.
+        *
+        * failed_tries == max_tries is the definition of the TPM lockout
+        * condition.
+        */
+       u32 failed_tries;       /* gp.failedTries */
+       u32 max_tries;  /* gp.maxTries */
+       /* The below fields are present in version 2 and above */
+};
+
 /* Wait for interrupt to indicate TPM is ready */
 static int cr50_i2c_wait_tpm_ready(struct udevice *dev)
 {
@@ -573,6 +654,87 @@ static int cr50_i2c_get_desc(struct udevice *dev, char *buf, int size)
        return len;
 }
 
+static int stringify_state(char *buf, int len, char *str, size_t max_size)
+{
+       struct tpm_vendor_state state;
+       size_t text_size = 0;
+
+       state.version = get_unaligned_be32(buf +
+               offsetof(struct tpm_vendor_state, version));
+       state.fail_line = get_unaligned_be32(buf +
+               offsetof(struct tpm_vendor_state, fail_line));
+       state.fail_code = get_unaligned_be32(buf +
+               offsetof(struct tpm_vendor_state, fail_code));
+       memcpy(state.func_name,
+              buf + offsetof(struct tpm_vendor_state, func_name),
+              sizeof(state.func_name));
+       state.failed_tries = get_unaligned_be32(buf +
+               offsetof(struct tpm_vendor_state, failed_tries));
+       state.max_tries = get_unaligned_be32(buf +
+               offsetof(struct tpm_vendor_state, max_tries));
+
+       text_size += snprintf(str + text_size, max_size - text_size,
+                             "v=%d", state.version);
+       if (text_size >= max_size)
+               return -ENOSPC;
+
+       if (state.version > TPM_STATE_VERSION)
+               text_size += snprintf(str + text_size,
+                                     max_size - text_size,
+                                     " not fully supported\n");
+       if (text_size >= max_size)
+               return -ENOSPC;
+
+       if (state.version == 0)
+               return -EINVAL; /* This should never happen */
+
+       text_size += snprintf(str + text_size,
+                             max_size - text_size,
+                             " failed_tries=%d max_tries=%d\n",
+                             state.failed_tries, state.max_tries);
+       if (text_size >= max_size)
+               return -ENOSPC;
+
+       if (state.fail_line) {
+               /* make sure function name is zero terminated. */
+               char func_name[sizeof(state.func_name) + 1];
+
+               memcpy(func_name, state.func_name, sizeof(state.func_name));
+               func_name[sizeof(state.func_name)] = '\0';
+
+               text_size += snprintf(str + text_size,
+                                     max_size - text_size,
+                                     "tpm failed: f %s line %d code %d",
+                                     func_name,
+                                     state.fail_line,
+                                     state.fail_code);
+               if (text_size >= max_size)
+                       return -ENOSPC;
+       }
+
+       return 0;
+}
+
+static int cr50_i2c_report_state(struct udevice *dev, char *str, int str_max)
+{
+       char buf[50];
+       size_t buf_size = sizeof(buf);
+       int ret;
+
+       ret = tpm2_report_state(dev, TPM2_CR50_VENDOR_COMMAND,
+                               TPM2_CR50_SUB_CMD_REPORT_TPM_STATE,
+                               buf, &buf_size);
+       if (ret)
+               return ret;
+
+       /* TPM responded as expected */
+       ret = stringify_state(buf, buf_size, str, str_max);
+       if (ret)
+               return ret;
+
+       return 0;
+}
+
 static int cr50_i2c_open(struct udevice *dev)
 {
        char buf[80];
@@ -730,6 +892,7 @@ struct acpi_ops cr50_acpi_ops = {
 static const struct tpm_ops cr50_i2c_ops = {
        .open           = cr50_i2c_open,
        .get_desc       = cr50_i2c_get_desc,
+       .report_state   = cr50_i2c_report_state,
        .send           = cr50_i2c_send,
        .recv           = cr50_i2c_recv,
        .cleanup        = cr50_i2c_cleanup,
index e79c90b9395dc7975bf47f1334486f298eca59fb..36c6ac0be6ee7b2c6538dc3a751e9df7e66b4597 100644 (file)
@@ -658,4 +658,17 @@ u32 tpm2_disable_platform_hierarchy(struct udevice *dev);
 u32 tpm2_submit_command(struct udevice *dev, const u8 *sendbuf,
                        u8 *recvbuf, size_t *recv_size);
 
+/**
+ * tpm_cr50_report_state() - Report the Cr50 internal state
+ *
+ * @dev:       TPM device
+ * @vendor_cmd:        Vendor command number to send
+ * @vendor_subcmd: Vendor sub-command number to send
+ * @recvbuf:   Buffer to save the response to
+ * @recv_size: Pointer to the size of the response buffer
+ * Return: result of the operation
+ */
+u32 tpm2_report_state(struct udevice *dev, uint vendor_cmd, uint vendor_subcmd,
+                     u8 *recvbuf, size_t *recv_size);
+
 #endif /* __TPM_V2_H */
index 3e240bb4c67eca6d33098385de447b8b65b66036..edee9854a7c1040a356c2e735446ad79df4dedff 100644 (file)
@@ -679,3 +679,28 @@ u32 tpm2_submit_command(struct udevice *dev, const u8 *sendbuf,
 {
        return tpm_sendrecv_command(dev, sendbuf, recvbuf, recv_size);
 }
+
+u32 tpm2_report_state(struct udevice *dev, uint vendor_cmd, uint vendor_subcmd,
+                     u8 *recvbuf, size_t *recv_size)
+{
+       u8 command_v2[COMMAND_BUFFER_SIZE] = {
+               /* header 10 bytes */
+               tpm_u16(TPM2_ST_NO_SESSIONS),           /* TAG */
+               tpm_u32(10 + 2),                        /* Length */
+               tpm_u32(vendor_cmd),    /* Command code */
+
+               tpm_u16(vendor_subcmd),
+       };
+       int ret;
+
+       ret = tpm_sendrecv_command(dev, command_v2, recvbuf, recv_size);
+       log_debug("ret=%s, %x\n", dev->name, ret);
+       if (ret)
+               return ret;
+       if (*recv_size < 12)
+               return -ENODATA;
+       *recv_size -= 12;
+       memcpy(recvbuf, recvbuf + 12, *recv_size);
+
+       return 0;
+}