tpm: add TPM2_PCR_Allocate command

TPM2_PCR_Allocate command is required to reconfigure a TPM device
to enable or disable algorithms in run-time, thus this patch introduces
the implementation of PCR allocate APIs and adds related cmd functions
for testing.

To test the feature, ensure that TPM is started up.
Run pcr_allocate command to turn on/off an algorithm, multiple calls
are supported and all changes will be cached:
`tpm2 pcr_allocate <algorithm_name> <on|off>`
Run startup command with argument 'off' to shutdown the TPM.
`tpm2 startup TPM2_SU_CLEAR off`
Reboot the board via `reset` to activate the changes.

Signed-off-by: Raymond Mao <raymond.mao@linaro.org>
Acked-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>
Signed-off-by: Ilias Apalodimas <ilias.apalodimas@linaro.org>

lib/tpm-v2.c

@@ -400,6 +400,130 @@ u32 tpm2_get_capability(struct udevice *dev, u32 capability, u32 property,
 	return 0;
 }
 
+u32 tpm2_pcr_config_algo(struct udevice *dev, u32 algo_mask,
+			 struct tpml_pcr_selection *pcr, u32 *pcr_len)
+{
+	int i;
+
+	if (pcr->count > TPM2_NUM_PCR_BANKS)
+		return TPM_LIB_ERROR;
+
+	*pcr_len = sizeof(pcr->count);
+
+	for (i = 0; i < pcr->count; i++) {
+		struct tpms_pcr_selection *sel = &pcr->selection[i];
+		u8 pad = 0;
+		int j;
+
+		if (sel->size_of_select > TPM2_PCR_SELECT_MAX)
+			return TPM_LIB_ERROR;
+
+		/*
+		 * Found the algorithm (bank) that matches, and enable all PCR
+		 * bits.
+		 * TODO: only select the bits needed
+		 */
+		for (j = 0; j < ARRAY_SIZE(hash_algo_list); j++) {
+			if (hash_algo_list[j].hash_alg != sel->hash)
+				continue;
+
+			if (algo_mask & hash_algo_list[j].hash_mask)
+				pad = 0xff;
+		}
+
+		for (j = 0; j < sel->size_of_select; j++)
+			sel->pcr_select[j] = pad;
+
+		log_info("set bank[%d] %s %s\n", i,
+			 tpm2_algorithm_name(sel->hash),
+			 tpm2_is_active_bank(sel) ? "on" : "off");
+
+		*pcr_len += sizeof(sel->hash) + sizeof(sel->size_of_select) +
+			    sel->size_of_select;
+	}
+
+	return 0;
+}
+
+u32 tpm2_send_pcr_allocate(struct udevice *dev, const char *pw,
+			   const ssize_t pw_sz, struct tpml_pcr_selection *pcr,
+			   u32 pcr_len)
+{
+	/* Length of the message header, up to start of password */
+	uint offset = 27;
+	u8 command_v2[COMMAND_BUFFER_SIZE] = {
+		tpm_u16(TPM2_ST_SESSIONS),   /* TAG */
+		tpm_u32(offset + pw_sz + pcr_len), /* Length */
+		tpm_u32(TPM2_CC_PCR_ALLOCATE),  /* Command code */
+
+		/* handles 4 bytes */
+		tpm_u32(TPM2_RH_PLATFORM),	/* Primary platform seed */
+
+		/* AUTH_SESSION */
+		tpm_u32(9 + pw_sz),		/* Authorization size */
+		tpm_u32(TPM2_RS_PW),		/* Session handle */
+		tpm_u16(0),			/* Size of <nonce> */
+						/* <nonce> (if any) */
+		0,				/* Attributes: Cont/Excl/Rst */
+		tpm_u16(pw_sz),			/* Size of <hmac/password> */
+		/* STRING(pw)			   <hmac/password> (if any) */
+
+		/* TPML_PCR_SELECTION */
+	};
+	u8 response[COMMAND_BUFFER_SIZE];
+	size_t response_len = COMMAND_BUFFER_SIZE;
+	u32 i;
+	int ret;
+
+	/*
+	 * Fill the command structure starting from the first buffer:
+	 * the password (if any)
+	 */
+	if (pack_byte_string(command_v2, sizeof(command_v2), "s", offset, pw,
+			     pw_sz))
+		return TPM_LIB_ERROR;
+
+	offset += pw_sz;
+
+	/* Pack the count field */
+	if (pack_byte_string(command_v2, sizeof(command_v2), "d", offset, pcr->count))
+		return TPM_LIB_ERROR;
+
+	offset += sizeof(pcr->count);
+
+	/* Pack each tpms_pcr_selection */
+	for (i = 0; i < pcr->count; i++) {
+		struct tpms_pcr_selection *sel = &pcr->selection[i];
+
+		/* Pack hash (16-bit) */
+		if (pack_byte_string(command_v2, sizeof(command_v2), "w", offset,
+				     sel->hash))
+			return TPM_LIB_ERROR;
+
+		offset += sizeof(sel->hash);
+
+		/* Pack size_of_select (8-bit) */
+		if (pack_byte_string(command_v2, sizeof(command_v2), "b", offset,
+				     sel->size_of_select))
+			return TPM_LIB_ERROR;
+
+		offset += sizeof(sel->size_of_select);
+
+		/* Pack pcr_select array */
+		if (pack_byte_string(command_v2, sizeof(command_v2), "s", offset,
+				     sel->pcr_select, sel->size_of_select))
+			return TPM_LIB_ERROR;
+
+		offset += sel->size_of_select;
+	}
+
+	ret = tpm_sendrecv_command(dev, command_v2, response, &response_len);
+	if (!ret)
+		tpm_init(dev);
+
+	return ret;
+}
+
 static int tpm2_get_num_pcr(struct udevice *dev, u32 *num_pcr)
 {
 	u8 response[(sizeof(struct tpms_capability_data) -