soc/amd/common/psp: add helper functions to retrieve capability bits

Add helper functions to send the PSP commands to query the fTPM and
PSP capability bits as well as the HSTI state. All SoCs using any PSP
generation support the MBOX_BIOS_CMD_PSP_FTPM_QUERY command and some
generation 1 and all generation 2 PSP SoCs support the
MBOX_BIOS_CMD_HSTI_QUERY command, so implement those two in the common
psp.c. Only PSP generation 2 supports the MBOX_BIOS_CMD_PSP_CAPS_QUERY
command, so implement that one in psp_gen2.c.

This code is ported and modified from
github.com/teslamotors/coreboot/tree/tesla-4.12-amd

Document #54267 revision 1.06 was used as reference for the 1st PSP
generation and document #55758 revision 2.04 was used for the 2nd PSP
generation.

Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: I4e17f994fb332690828c55742262da793e297d99
Reviewed-on: https://review.coreboot.org/c/coreboot/+/84066
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Matt DeVillier <matt.devillier@amd.corp-partner.google.com>
Reviewed-by: Marshall Dawson <marshalldawson3rd@gmail.com>

1 files changed, 46 insertions, 0 deletions

diff --git a/src/soc/amd/common/block/psp/psp.c b/src/soc/amd/common/block/psp/psp.c
index f989a3b007..a8bb20535e 100644
--- a/src/soc/amd/common/block/psp/psp.c
+++ b/src/soc/amd/common/block/psp/psp.c
@@ -55,6 +55,52 @@ void psp_print_cmd_status(int cmd_status, struct mbox_buffer_header *header)
 		printk(BIOS_DEBUG, "OK\n");
 }
 
+enum cb_err psp_get_ftpm_capabilties(uint32_t *capabilities)
+{
+	int cmd_status;
+	struct mbox_cmd_capability_query_buffer buffer = {
+		.header = {
+			.size = sizeof(buffer)
+		},
+	};
+
+	printk(BIOS_DEBUG, "PSP: Querying fTPM capabilities...");
+
+	cmd_status = send_psp_command(MBOX_BIOS_CMD_PSP_FTPM_QUERY, &buffer);
+
+	/* buffer's status shouldn't change but report it if it does */
+	psp_print_cmd_status(cmd_status, &buffer.header);
+
+	if (!cmd_status)
+		return CB_ERR;
+
+	*capabilities = read32(&buffer.capabilities);
+	return CB_SUCCESS;
+}
+
+enum cb_err psp_get_hsti_state(uint32_t *state)
+{
+	int cmd_status;
+	struct mbox_cmd_hsti_query_buffer buffer = {
+		.header = {
+			.size = sizeof(buffer)
+		},
+	};
+
+	printk(BIOS_DEBUG, "PSP: Querying HSTI state...");
+
+	cmd_status = send_psp_command(MBOX_BIOS_CMD_HSTI_QUERY, &buffer);
+
+	/* buffer's status shouldn't change but report it if it does */
+	psp_print_cmd_status(cmd_status, &buffer.header);
+
+	if (!cmd_status)
+		return CB_ERR;
+
+	*state = read32(&buffer.state);
+	return CB_SUCCESS;
+}
+
 /*
  * Notify the PSP that the system is completing the boot process.  Upon
  * receiving this command, the PSP will only honor commands where the buffer