diff options
Diffstat (limited to 'hw/tpm/tpm_tis_i2c.c')
| -rw-r--r-- | hw/tpm/tpm_tis_i2c.c | 571 |
1 files changed, 571 insertions, 0 deletions
diff --git a/hw/tpm/tpm_tis_i2c.c b/hw/tpm/tpm_tis_i2c.c new file mode 100644 index 0000000000..b695fd3a46 --- /dev/null +++ b/hw/tpm/tpm_tis_i2c.c @@ -0,0 +1,571 @@ +/* + * tpm_tis_i2c.c - QEMU's TPM TIS I2C Device + * + * Copyright (c) 2023 IBM Corporation + * + * Authors: + * Ninad Palsule <ninad@linux.ibm.com> + * + * This work is licensed under the terms of the GNU GPL, version 2 or later. + * See the COPYING file in the top-level directory. + * + * TPM I2C implementation follows TCG TPM I2c Interface specification, + * Family 2.0, Level 00, Revision 1.00 + * + * TPM TIS for TPM 2 implementation following TCG PC Client Platform + * TPM Profile (PTP) Specification, Familiy 2.0, Revision 00.43 + * + */ + +#include "qemu/osdep.h" +#include "hw/i2c/i2c.h" +#include "hw/sysbus.h" +#include "hw/acpi/tpm.h" +#include "migration/vmstate.h" +#include "tpm_prop.h" +#include "qemu/log.h" +#include "trace.h" +#include "tpm_tis.h" + +/* Operations */ +#define OP_SEND 1 +#define OP_RECV 2 + +/* Is locality valid */ +#define TPM_TIS_I2C_IS_VALID_LOCTY(x) TPM_TIS_IS_VALID_LOCTY(x) + +typedef struct TPMStateI2C { + /*< private >*/ + I2CSlave parent_obj; + + uint8_t offset; /* offset into data[] */ + uint8_t operation; /* OP_SEND & OP_RECV */ + uint8_t data[5]; /* Data */ + + /* i2c registers */ + uint8_t loc_sel; /* Current locality */ + uint8_t csum_enable; /* Is checksum enabled */ + + /* Derived from the above */ + const char *reg_name; /* Register name */ + uint32_t tis_addr; /* Converted tis address including locty */ + + /*< public >*/ + TPMState state; /* not a QOM object */ + +} TPMStateI2C; + +DECLARE_INSTANCE_CHECKER(TPMStateI2C, TPM_TIS_I2C, + TYPE_TPM_TIS_I2C) + +/* Prototype */ +static inline void tpm_tis_i2c_to_tis_reg(TPMStateI2C *i2cst, uint8_t i2c_reg); + +/* Register map */ +typedef struct regMap { + uint8_t i2c_reg; /* I2C register */ + uint16_t tis_reg; /* TIS register */ + const char *reg_name; /* Register name */ +} I2CRegMap; + +/* + * The register values in the common code is different than the latest + * register numbers as per the spec hence add the conversion map + */ +static const I2CRegMap tpm_tis_reg_map[] = { + /* + * These registers are sent to TIS layer. The register with UNKNOWN + * mapping are not sent to TIS layer and handled in I2c layer. + * NOTE: Adding frequently used registers at the start + */ + { TPM_I2C_REG_DATA_FIFO, TPM_TIS_REG_DATA_FIFO, "FIFO", }, + { TPM_I2C_REG_STS, TPM_TIS_REG_STS, "STS", }, + { TPM_I2C_REG_DATA_CSUM_GET, TPM_I2C_REG_UNKNOWN, "CSUM_GET", }, + { TPM_I2C_REG_LOC_SEL, TPM_I2C_REG_UNKNOWN, "LOC_SEL", }, + { TPM_I2C_REG_ACCESS, TPM_TIS_REG_ACCESS, "ACCESS", }, + { TPM_I2C_REG_INT_ENABLE, TPM_TIS_REG_INT_ENABLE, "INTR_ENABLE",}, + { TPM_I2C_REG_INT_CAPABILITY, TPM_I2C_REG_UNKNOWN, "INTR_CAP", }, + { TPM_I2C_REG_INTF_CAPABILITY, TPM_TIS_REG_INTF_CAPABILITY, "INTF_CAP", }, + { TPM_I2C_REG_DID_VID, TPM_TIS_REG_DID_VID, "DID_VID", }, + { TPM_I2C_REG_RID, TPM_TIS_REG_RID, "RID", }, + { TPM_I2C_REG_I2C_DEV_ADDRESS, TPM_I2C_REG_UNKNOWN, "DEV_ADDRESS",}, + { TPM_I2C_REG_DATA_CSUM_ENABLE, TPM_I2C_REG_UNKNOWN, "CSUM_ENABLE",}, +}; + +static int tpm_tis_i2c_pre_save(void *opaque) +{ + TPMStateI2C *i2cst = opaque; + + return tpm_tis_pre_save(&i2cst->state); +} + +static int tpm_tis_i2c_post_load(void *opaque, int version_id) +{ + TPMStateI2C *i2cst = opaque; + + if (i2cst->offset >= 1) { + tpm_tis_i2c_to_tis_reg(i2cst, i2cst->data[0]); + } + + return 0; +} + +static const VMStateDescription vmstate_tpm_tis_i2c = { + .name = "tpm-tis-i2c", + .version_id = 0, + .pre_save = tpm_tis_i2c_pre_save, + .post_load = tpm_tis_i2c_post_load, + .fields = (VMStateField[]) { + VMSTATE_BUFFER(state.buffer, TPMStateI2C), + VMSTATE_UINT16(state.rw_offset, TPMStateI2C), + VMSTATE_UINT8(state.active_locty, TPMStateI2C), + VMSTATE_UINT8(state.aborting_locty, TPMStateI2C), + VMSTATE_UINT8(state.next_locty, TPMStateI2C), + + VMSTATE_STRUCT_ARRAY(state.loc, TPMStateI2C, TPM_TIS_NUM_LOCALITIES, 0, + vmstate_locty, TPMLocality), + + /* i2c specifics */ + VMSTATE_UINT8(offset, TPMStateI2C), + VMSTATE_UINT8(operation, TPMStateI2C), + VMSTATE_BUFFER(data, TPMStateI2C), + VMSTATE_UINT8(loc_sel, TPMStateI2C), + VMSTATE_UINT8(csum_enable, TPMStateI2C), + + VMSTATE_END_OF_LIST() + } +}; + +/* + * Set data value. The i2cst->offset is not updated as called in + * the read path. + */ +static void tpm_tis_i2c_set_data(TPMStateI2C *i2cst, uint32_t data) +{ + i2cst->data[1] = data; + i2cst->data[2] = data >> 8; + i2cst->data[3] = data >> 16; + i2cst->data[4] = data >> 24; +} +/* + * Generate interface capability based on what is returned by TIS and what is + * expected by I2C. Save the capability in the data array overwriting the TIS + * capability. + */ +static uint32_t tpm_tis_i2c_interface_capability(TPMStateI2C *i2cst, + uint32_t tis_cap) +{ + uint32_t i2c_cap; + + /* Now generate i2c capability */ + i2c_cap = (TPM_I2C_CAP_INTERFACE_TYPE | + TPM_I2C_CAP_INTERFACE_VER | + TPM_I2C_CAP_TPM2_FAMILY | + TPM_I2C_CAP_LOCALITY_CAP | + TPM_I2C_CAP_BUS_SPEED | + TPM_I2C_CAP_DEV_ADDR_CHANGE); + + /* Now check the TIS and set some capabilities */ + + /* Static burst count set */ + if (tis_cap & TPM_TIS_CAP_BURST_COUNT_STATIC) { + i2c_cap |= TPM_I2C_CAP_BURST_COUNT_STATIC; + } + + return i2c_cap; +} + +/* Convert I2C register to TIS address and returns the name of the register */ +static inline void tpm_tis_i2c_to_tis_reg(TPMStateI2C *i2cst, uint8_t i2c_reg) +{ + const I2CRegMap *reg_map; + int i; + + i2cst->tis_addr = 0xffffffff; + + /* Special case for the STS register. */ + if (i2c_reg >= TPM_I2C_REG_STS && i2c_reg <= TPM_I2C_REG_STS + 3) { + i2c_reg = TPM_I2C_REG_STS; + } + + for (i = 0; i < ARRAY_SIZE(tpm_tis_reg_map); i++) { + reg_map = &tpm_tis_reg_map[i]; + if (reg_map->i2c_reg == i2c_reg) { + i2cst->reg_name = reg_map->reg_name; + i2cst->tis_addr = reg_map->tis_reg; + + /* Include the locality in the address. */ + assert(TPM_TIS_I2C_IS_VALID_LOCTY(i2cst->loc_sel)); + i2cst->tis_addr += (i2cst->loc_sel << TPM_TIS_LOCALITY_SHIFT); + break; + } + } +} + +/* Clear some fields from the structure. */ +static inline void tpm_tis_i2c_clear_data(TPMStateI2C *i2cst) +{ + /* Clear operation and offset */ + i2cst->operation = 0; + i2cst->offset = 0; + i2cst->tis_addr = 0xffffffff; + i2cst->reg_name = NULL; + memset(i2cst->data, 0, sizeof(i2cst->data)); + + return; +} + +/* Send data to TPM */ +static inline void tpm_tis_i2c_tpm_send(TPMStateI2C *i2cst) +{ + uint32_t data; + size_t offset = 0; + uint32_t sz = 4; + + if ((i2cst->operation == OP_SEND) && (i2cst->offset > 1)) { + + switch (i2cst->data[0]) { + case TPM_I2C_REG_DATA_CSUM_ENABLE: + /* + * Checksum is not handled by TIS code hence we will consume the + * register here. + */ + i2cst->csum_enable = i2cst->data[1] & TPM_DATA_CSUM_ENABLED; + break; + case TPM_I2C_REG_DATA_FIFO: + /* Handled in the main i2c_send function */ + break; + case TPM_I2C_REG_LOC_SEL: + /* + * This register is not handled by TIS so save the locality + * locally + */ + if (TPM_TIS_I2C_IS_VALID_LOCTY(i2cst->data[1])) { + i2cst->loc_sel = i2cst->data[1]; + } + break; + default: + /* We handle non-FIFO here */ + + /* Index 0 is a register. Convert byte stream to uint32_t */ + data = i2cst->data[1]; + data |= i2cst->data[2] << 8; + data |= i2cst->data[3] << 16; + data |= i2cst->data[4] << 24; + + /* Add register specific masking */ + switch (i2cst->data[0]) { + case TPM_I2C_REG_INT_ENABLE: + data &= TPM_I2C_INT_ENABLE_MASK; + break; + case TPM_I2C_REG_STS ... TPM_I2C_REG_STS + 3: + /* + * STS register has 4 bytes data. + * As per the specs following writes must be allowed. + * - From base address 1 to 4 bytes are allowed. + * - Single byte write to first or last byte must + * be allowed. + */ + offset = i2cst->data[0] - TPM_I2C_REG_STS; + if (offset > 0) { + sz = 1; + } + data &= (TPM_I2C_STS_WRITE_MASK >> (offset * 8)); + break; + } + + tpm_tis_write_data(&i2cst->state, i2cst->tis_addr + offset, data, + sz); + break; + } + + tpm_tis_i2c_clear_data(i2cst); + } + + return; +} + +/* Callback from TPM to indicate that response is copied */ +static void tpm_tis_i2c_request_completed(TPMIf *ti, int ret) +{ + TPMStateI2C *i2cst = TPM_TIS_I2C(ti); + TPMState *s = &i2cst->state; + + /* Inform the common code. */ + tpm_tis_request_completed(s, ret); +} + +static enum TPMVersion tpm_tis_i2c_get_tpm_version(TPMIf *ti) +{ + TPMStateI2C *i2cst = TPM_TIS_I2C(ti); + TPMState *s = &i2cst->state; + + return tpm_tis_get_tpm_version(s); +} + +static int tpm_tis_i2c_event(I2CSlave *i2c, enum i2c_event event) +{ + TPMStateI2C *i2cst = TPM_TIS_I2C(i2c); + int ret = 0; + + switch (event) { + case I2C_START_RECV: + trace_tpm_tis_i2c_event("START_RECV"); + break; + case I2C_START_SEND: + trace_tpm_tis_i2c_event("START_SEND"); + tpm_tis_i2c_clear_data(i2cst); + break; + case I2C_FINISH: + trace_tpm_tis_i2c_event("FINISH"); + if (i2cst->operation == OP_SEND) { + tpm_tis_i2c_tpm_send(i2cst); + } else { + tpm_tis_i2c_clear_data(i2cst); + } + break; + default: + break; + } + + return ret; +} + +/* + * If data is for FIFO then it is received from tpm_tis_common buffer + * otherwise it will be handled using single call to common code and + * cached in the local buffer. + */ +static uint8_t tpm_tis_i2c_recv(I2CSlave *i2c) +{ + int ret = 0; + uint32_t data_read; + TPMStateI2C *i2cst = TPM_TIS_I2C(i2c); + TPMState *s = &i2cst->state; + uint16_t i2c_reg = i2cst->data[0]; + size_t offset; + + if (i2cst->operation == OP_RECV) { + + /* Do not cache FIFO data. */ + if (i2cst->data[0] == TPM_I2C_REG_DATA_FIFO) { + data_read = tpm_tis_read_data(s, i2cst->tis_addr, 1); + ret = (data_read & 0xff); + } else if (i2cst->offset < sizeof(i2cst->data)) { + ret = i2cst->data[i2cst->offset++]; + } + + } else if ((i2cst->operation == OP_SEND) && (i2cst->offset < 2)) { + /* First receive call after send */ + + i2cst->operation = OP_RECV; + + switch (i2c_reg) { + case TPM_I2C_REG_LOC_SEL: + /* Location selection register is managed by i2c */ + tpm_tis_i2c_set_data(i2cst, i2cst->loc_sel); + break; + case TPM_I2C_REG_DATA_FIFO: + /* FIFO data is directly read from TPM TIS */ + data_read = tpm_tis_read_data(s, i2cst->tis_addr, 1); + tpm_tis_i2c_set_data(i2cst, (data_read & 0xff)); + break; + case TPM_I2C_REG_DATA_CSUM_ENABLE: + tpm_tis_i2c_set_data(i2cst, i2cst->csum_enable); + break; + case TPM_I2C_REG_INT_CAPABILITY: + /* + * Interrupt is not supported in the linux kernel hence we cannot + * test this model with interrupts. + */ + tpm_tis_i2c_set_data(i2cst, TPM_I2C_INT_ENABLE_MASK); + break; + case TPM_I2C_REG_DATA_CSUM_GET: + /* + * Checksum registers are not supported by common code hence + * call a common code to get the checksum. + */ + data_read = tpm_tis_get_checksum(s); + + /* Save the byte stream in data field */ + tpm_tis_i2c_set_data(i2cst, data_read); + break; + default: + data_read = tpm_tis_read_data(s, i2cst->tis_addr, 4); + + switch (i2c_reg) { + case TPM_I2C_REG_INTF_CAPABILITY: + /* Prepare the capabilities as per I2C interface */ + data_read = tpm_tis_i2c_interface_capability(i2cst, + data_read); + break; + case TPM_I2C_REG_STS ... TPM_I2C_REG_STS + 3: + offset = i2c_reg - TPM_I2C_REG_STS; + /* + * As per specs, STS bit 31:26 are reserved and must + * be set to 0 + */ + data_read &= TPM_I2C_STS_READ_MASK; + /* + * STS register has 4 bytes data. + * As per the specs following reads must be allowed. + * - From base address 1 to 4 bytes are allowed. + * - Last byte must be allowed to read as a single byte + * - Second and third byte must be allowed to read as two + * two bytes. + */ + data_read >>= (offset * 8); + break; + } + + /* Save byte stream in data[] */ + tpm_tis_i2c_set_data(i2cst, data_read); + break; + } + + /* Return first byte with this call */ + i2cst->offset = 1; /* keep the register value intact for debug */ + ret = i2cst->data[i2cst->offset++]; + } else { + i2cst->operation = OP_RECV; + } + + trace_tpm_tis_i2c_recv(ret); + + return ret; +} + +/* + * Send function only remembers data in the buffer and then calls + * TPM TIS common code during FINISH event. + */ +static int tpm_tis_i2c_send(I2CSlave *i2c, uint8_t data) +{ + TPMStateI2C *i2cst = TPM_TIS_I2C(i2c); + + /* Reject non-supported registers. */ + if (i2cst->offset == 0) { + /* Convert I2C register to TIS register */ + tpm_tis_i2c_to_tis_reg(i2cst, data); + if (i2cst->tis_addr == 0xffffffff) { + return 0xffffffff; + } + + trace_tpm_tis_i2c_send_reg(i2cst->reg_name, data); + + /* We do not support device address change */ + if (data == TPM_I2C_REG_I2C_DEV_ADDRESS) { + qemu_log_mask(LOG_UNIMP, "%s: Device address change " + "is not supported.\n", __func__); + return 0xffffffff; + } + } else { + trace_tpm_tis_i2c_send(data); + } + + if (i2cst->offset < sizeof(i2cst->data)) { + i2cst->operation = OP_SEND; + + /* + * In two cases, we save values in the local buffer. + * 1) The first value is always a register. + * 2) In case of non-FIFO multibyte registers, TIS expects full + * register value hence I2C layer cache the register value and send + * to TIS during FINISH event. + */ + if ((i2cst->offset == 0) || + (i2cst->data[0] != TPM_I2C_REG_DATA_FIFO)) { + i2cst->data[i2cst->offset++] = data; + } else { + /* + * The TIS can process FIFO data one byte at a time hence the FIFO + * data is sent to TIS directly. + */ + tpm_tis_write_data(&i2cst->state, i2cst->tis_addr, data, 1); + } + + return 0; + } + + /* Return non-zero to indicate NAK */ + return 1; +} + +static Property tpm_tis_i2c_properties[] = { + DEFINE_PROP_TPMBE("tpmdev", TPMStateI2C, state.be_driver), + DEFINE_PROP_END_OF_LIST(), +}; + +static void tpm_tis_i2c_realizefn(DeviceState *dev, Error **errp) +{ + TPMStateI2C *i2cst = TPM_TIS_I2C(dev); + TPMState *s = &i2cst->state; + + if (!tpm_find()) { + error_setg(errp, "at most one TPM device is permitted"); + return; + } + + /* + * Get the backend pointer. It is not initialized propery during + * device_class_set_props + */ + s->be_driver = qemu_find_tpm_be("tpm0"); + + if (!s->be_driver) { + error_setg(errp, "'tpmdev' property is required"); + return; + } +} + +static void tpm_tis_i2c_reset(DeviceState *dev) +{ + TPMStateI2C *i2cst = TPM_TIS_I2C(dev); + TPMState *s = &i2cst->state; + + tpm_tis_i2c_clear_data(i2cst); + + i2cst->csum_enable = 0; + i2cst->loc_sel = 0x00; + + return tpm_tis_reset(s); +} + +static void tpm_tis_i2c_class_init(ObjectClass *klass, void *data) +{ + DeviceClass *dc = DEVICE_CLASS(klass); + I2CSlaveClass *k = I2C_SLAVE_CLASS(klass); + TPMIfClass *tc = TPM_IF_CLASS(klass); + + dc->realize = tpm_tis_i2c_realizefn; + dc->reset = tpm_tis_i2c_reset; + dc->vmsd = &vmstate_tpm_tis_i2c; + device_class_set_props(dc, tpm_tis_i2c_properties); + set_bit(DEVICE_CATEGORY_MISC, dc->categories); + + k->event = tpm_tis_i2c_event; + k->recv = tpm_tis_i2c_recv; + k->send = tpm_tis_i2c_send; + + tc->model = TPM_MODEL_TPM_TIS; + tc->request_completed = tpm_tis_i2c_request_completed; + tc->get_version = tpm_tis_i2c_get_tpm_version; +} + +static const TypeInfo tpm_tis_i2c_info = { + .name = TYPE_TPM_TIS_I2C, + .parent = TYPE_I2C_SLAVE, + .instance_size = sizeof(TPMStateI2C), + .class_init = tpm_tis_i2c_class_init, + .interfaces = (InterfaceInfo[]) { + { TYPE_TPM_IF }, + { } + } +}; + +static void tpm_tis_i2c_register_types(void) +{ + type_register_static(&tpm_tis_i2c_info); +} + +type_init(tpm_tis_i2c_register_types) |