Add PCR allocate wrapper APIs for using in tcg2 protocol.
The wrapper proceeds a PCR allocate command, followed by a
shutdown command.
A system boot is required after two commands since TPM device needs
a HW reset to activate the new algorithms config.
Also, a helper function is included to determine the new bank mask
for PCR allocation by combining the status of current active,
supported and eventlog bank masks.
A new kconfig is created. PCR allocate and system reboot only
happens when the kconfig is selected, otherwise just exit with
errors.
Signed-off-by: Raymond Mao <raymond....@linaro.org>
---
 include/tpm-v2.h |  20 ++++++++
 lib/Kconfig      |  12 +++++
 lib/tpm-v2.c     | 121 +++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 153 insertions(+)

diff --git a/include/tpm-v2.h b/include/tpm-v2.h
index af3158f6e4..79dc4a34e2 100644
--- a/include/tpm-v2.h
+++ b/include/tpm-v2.h
@@ -703,6 +703,17 @@ u32 tpm2_report_state(struct udevice *dev, uint 
vendor_cmd, uint vendor_subcmd,
 u32 tpm2_enable_nvcommits(struct udevice *dev, uint vendor_cmd,
                          uint vendor_subcmd);
 
+/**
+ * tpm2_pcr_allocate_get_mask - Get algorithm bitmask for PCR allocate
+ *
+ * @dev                TPM device
+ * @log_active Active algorithm bitmask
+ * @mask       Bitmask for PCR allocate
+ *
+ * Return: zero on success, negative errno otherwise
+ */
+int tpm2_pcr_allocate_get_mask(struct udevice *dev, u32 log_active, u32 *mask);
+
 /**
  * tpm2_pcr_config_algo() - Allocate the active PCRs. Requires reboot
  *
@@ -730,6 +741,15 @@ u32 tpm2_pcr_config_algo(struct udevice *dev, u32 
algo_mask,
 u32 tpm2_send_pcr_allocate(struct udevice *dev, const char *pw,
                           const ssize_t pw_sz, struct tpml_pcr_selection *pcr,
                           u32 pcr_len);
+/**
+ * tpm2_pcr_allocate() - Allocate the PCRs
+ *
+ * @param dev   TPM device
+ * @log_active Bitmask of eventlog algorithms
+ *
+ * Return: code of the operation
+ */
+int tpm2_pcr_allocate(struct udevice *dev, u32 log_active);
 
 /**
  * tpm2_auto_start() - start up the TPM and perform selftests.
diff --git a/lib/Kconfig b/lib/Kconfig
index baeb615626..0732333849 100644
--- a/lib/Kconfig
+++ b/lib/Kconfig
@@ -514,6 +514,18 @@ config VPL_TPM
          for the low-level TPM interface, but only one TPM is supported at
          a time by the TPM library.
 
+config TPM_PCR_ALLOCATE
+       bool "Re-configurate TPM algorithms in run-time (PCR allocate)"
+       depends on TPM_V2 && (MEASURED_BOOT || EFI_TCG2_PROTOCOL)
+       help
+         This enables a detection for the dismatches of algorithms among TPM
+         device, eventlog from previous boot stage and U-Boot support.
+         A PCR allocate command will be sent to reconfigurate the TPM device
+         in run-time to make sure algorithms in TPM device, eventlog and
+         U-Boot are aligned with each other.
+         A system reboot will be proceeded after then to activate the new
+         algorithms.
+
 endmenu
 
 menu "Android Verified Boot"
diff --git a/lib/tpm-v2.c b/lib/tpm-v2.c
index 045b5dd9eb..71abf070de 100644
--- a/lib/tpm-v2.c
+++ b/lib/tpm-v2.c
@@ -44,6 +44,127 @@ static int tpm2_update_active_banks(struct udevice *dev)
        return 0;
 }
 
+static void tpm2_print_selected_algorithm_name(u32 selected)
+{
+       size_t i;
+       const char *str;
+
+       for (i = 0; i < ARRAY_SIZE(hash_algo_list); i++) {
+               const struct digest_info *algo = &hash_algo_list[i];
+
+               if (!(selected & algo->hash_mask))
+                       continue;
+
+               str = tpm2_algorithm_name(algo->hash_alg);
+               if (str)
+                       log_info("%s\n", str);
+       }
+}
+
+int tpm2_pcr_allocate_get_mask(struct udevice *dev, u32 log_active, u32 *mask)
+{
+       struct tpml_pcr_selection pcrs;
+       u32 active = 0;
+       u32 supported = 0;
+       int rc, i;
+
+       *mask = 0;
+
+       rc = tpm2_get_pcr_info(dev, &pcrs);
+       if (rc)
+               return rc;
+
+       for (i = 0; i < pcrs.count; i++) {
+               struct tpms_pcr_selection *sel = &pcrs.selection[i];
+               size_t j;
+               u32 hash_mask = 0;
+
+               for (j = 0; j < ARRAY_SIZE(hash_algo_list); j++) {
+                       if (hash_algo_list[j].hash_alg == sel->hash)
+                               hash_mask = hash_algo_list[j].hash_mask;
+               }
+
+               if (tpm2_algorithm_supported(sel->hash))
+                       supported |= hash_mask;
+
+               if (tpm2_is_active_bank(sel))
+                       active |= hash_mask;
+       }
+
+       /* All eventlog algorithm(s) must be supported */
+       if (log_active & ~supported) {
+               log_err("EventLog contains U-Boot unsupported algorithm(s)\n");
+               tpm2_print_selected_algorithm_name(log_active & ~supported);
+               rc = -1;
+       }
+       if (log_active && active & ~log_active) {
+               log_warning("TPM active algorithm(s) not exist in eventlog\n");
+               tpm2_print_selected_algorithm_name(active & ~log_active);
+               *mask = log_active;
+       }
+
+       /* Any active algorithm(s) which are not supported must be removed */
+       if (active & ~supported) {
+               log_warning("TPM active algorithm(s) unsupported by u-boot\n");
+               tpm2_print_selected_algorithm_name(active & ~supported);
+               if (*mask)
+                       *mask = active & supported & *mask;
+               else
+                       *mask = active & supported;
+       }
+
+       return rc;
+}
+
+static int tpm2_proceed_pcr_allocate(struct udevice *dev, u32 algo_mask)
+{
+       struct tpml_pcr_selection pcr = { 0 };
+       u32 pcr_len = 0;
+       int rc;
+
+       rc = tpm2_get_pcr_info(dev, &pcr);
+       if (rc)
+               return rc;
+
+       rc = tpm2_pcr_config_algo(dev, algo_mask, &pcr, &pcr_len);
+       if (rc)
+               return rc;
+
+       /* Assume no password */
+       rc = tpm2_send_pcr_allocate(dev, NULL, 0, &pcr, pcr_len);
+       if (rc)
+               return rc;
+
+       /* Send TPM2_Shutdown, assume mode = TPM2_SU_CLEAR */
+       return tpm2_startup(dev, false, TPM2_SU_CLEAR);
+}
+
+int tpm2_pcr_allocate(struct udevice *dev, u32 log_active)
+{
+       u32 algo_mask = 0;
+       int rc;
+
+       rc = tpm2_pcr_allocate_get_mask(dev, log_active, &algo_mask);
+       if (rc)
+               return rc;
+
+       if (algo_mask) {
+               if (!IS_ENABLED(CONFIG_TPM_PCR_ALLOCATE))
+                       return -1;
+
+               rc = tpm2_proceed_pcr_allocate(dev, algo_mask);
+               if (rc)
+                       return rc;
+
+               log_info("PCR allocate done, shutdown TPM and reboot\n");
+               do_reset(NULL, 0, 0, NULL);
+               log_err("reset does not work!\n");
+               return -1;
+       }
+
+       return 0;
+}
+
 u32 tpm2_startup(struct udevice *dev, bool bon, enum tpm2_startup_types mode)
 {
        int op = bon ? TPM2_CC_STARTUP : TPM2_CC_SHUTDOWN;
-- 
2.25.1

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