| /* SPDX-License-Identifier: GPL-2.0-only */ |
| |
| #include <types.h> |
| #include <acpi/acpigen.h> |
| #include <acpi/acpi_device.h> |
| |
| #include "tpm_ppi.h" |
| |
| static void tpm_ppi_func0_cb(void *arg) |
| { |
| /* Functions 1-8. */ |
| u8 buf[] = {0xff, 0x01}; |
| acpigen_write_return_byte_buffer(buf, sizeof(buf)); |
| } |
| |
| static void tpm_ppi_func1_cb(void *arg) |
| { |
| if (CONFIG(TPM2)) |
| /* Interface version: 1.3 */ |
| acpigen_write_return_string("1.3"); |
| else |
| /* Interface version: 1.2 */ |
| acpigen_write_return_string("1.2"); |
| } |
| |
| static void tpm_ppi_func2_cb(void *arg) |
| { |
| /* Submit operations: drop on the floor and return success. */ |
| acpigen_write_return_byte(PPI2_RET_SUCCESS); |
| } |
| |
| static void tpm_ppi_func3_cb(void *arg) |
| { |
| /* Pending operation: none. */ |
| acpigen_emit_byte(RETURN_OP); |
| acpigen_write_package(2); |
| acpigen_write_byte(0); |
| acpigen_write_byte(0); |
| acpigen_pop_len(); |
| } |
| |
| static void tpm_ppi_func4_cb(void *arg) |
| { |
| /* Pre-OS transition method: reboot. */ |
| acpigen_write_return_byte(2); |
| } |
| |
| static void tpm_ppi_func5_cb(void *arg) |
| { |
| /* Operation response: no operation executed. */ |
| acpigen_emit_byte(RETURN_OP); |
| acpigen_write_package(3); |
| acpigen_write_byte(0); |
| acpigen_write_byte(0); |
| acpigen_write_byte(0); |
| acpigen_pop_len(); |
| } |
| |
| static void tpm_ppi_func6_cb(void *arg) |
| { |
| /* |
| * Set preferred user language: deprecated and must return 3 AKA |
| * "not implemented". |
| */ |
| acpigen_write_return_byte(PPI6_RET_NOT_IMPLEMENTED); |
| } |
| |
| static void tpm_ppi_func7_cb(void *arg) |
| { |
| /* Submit operations: deny. */ |
| acpigen_write_return_byte(PPI7_RET_BLOCKED_BY_FIRMWARE); |
| } |
| |
| static void tpm_ppi_func8_cb(void *arg) |
| { |
| /* All actions are forbidden. */ |
| acpigen_write_return_byte(PPI8_RET_FIRMWARE_ONLY); |
| } |
| |
| static void (*tpm_ppi_callbacks[])(void *) = { |
| tpm_ppi_func0_cb, |
| tpm_ppi_func1_cb, |
| tpm_ppi_func2_cb, |
| tpm_ppi_func3_cb, |
| tpm_ppi_func4_cb, |
| tpm_ppi_func5_cb, |
| tpm_ppi_func6_cb, |
| tpm_ppi_func7_cb, |
| tpm_ppi_func8_cb, |
| }; |
| |
| static void tpm_mci_func0_cb(void *arg) |
| { |
| /* Function 1. */ |
| acpigen_write_return_singleton_buffer(0x3); |
| } |
| static void tpm_mci_func1_cb(void *arg) |
| { |
| /* Just return success. */ |
| acpigen_write_return_byte(0); |
| } |
| |
| static void (*tpm_mci_callbacks[])(void *) = { |
| tpm_mci_func0_cb, |
| tpm_mci_func1_cb, |
| }; |
| |
| void tpm_ppi_acpi_fill_ssdt(const struct device *dev) |
| { |
| /* |
| * _DSM method |
| */ |
| struct dsm_uuid ids[] = { |
| /* Physical presence interface. |
| * This is used to submit commands like "Clear TPM" to |
| * be run at next reboot provided that user confirms |
| * them. Spec allows user to cancel all commands and/or |
| * configure BIOS to reject commands. So we pretend that |
| * user did just this: cancelled everything. If user |
| * really wants to clear TPM the only option now is to |
| * do it manually in payload. |
| */ |
| DSM_UUID(TPM_PPI_UUID, tpm_ppi_callbacks, |
| ARRAY_SIZE(tpm_ppi_callbacks), NULL), |
| /* Memory clearing on boot: just a dummy. */ |
| DSM_UUID(TPM_MCI_UUID, tpm_mci_callbacks, |
| ARRAY_SIZE(tpm_mci_callbacks), NULL), |
| }; |
| |
| acpigen_write_dsm_uuid_arr(ids, ARRAY_SIZE(ids)); |
| } |