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drivers/tpm/spi: Convert static functions to enum cb_err return types 

Instead of using raw integers to indicate success/failure, enum cb_err
can be used to makes things clearer, so this patch converts most
functions to return that instead of int.

TEST=boot to OS on google/dratini, no TPM errors seen

Signed-off-by: Tim Wawrzynczak <twawrzynczak@chromium.org>
Change-Id: Ifb749c931fe008b16d42fcf157af820ec8fbf5ac
Reviewed-on: https://review.coreboot.org/c/coreboot/+/61976
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
This commit is contained in:
Tim Wawrzynczak 2022-02-15 17:59:58 -07:00 committed by Felix Held
parent d736fd4ea7
commit 591c7ebf18
1 changed files with 71 additions and 73 deletions
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144
src/drivers/spi/tpm/tpm.c
View File

@ -16,9 +16,10 @@
#include <console/console.h> #include <console/console.h>
#include <delay.h> #include <delay.h>
#include <endian.h> #include <endian.h>
#include <security/tpm/tis.h>
#include <string.h> #include <string.h>
#include <timer.h> #include <timer.h>
#include <security/tpm/tis.h> #include <types.h>
#include "tpm.h" #include "tpm.h"
@ -86,30 +87,25 @@ __weak int tis_plat_irq_status(void)
/* /*
* TPM may trigger a IRQ after finish processing previous transfer. * TPM may trigger a IRQ after finish processing previous transfer.
* Waiting for this IRQ to sync TPM status. * Waiting for this IRQ to sync TPM status.
*
* Returns 1 on success, 0 on failure (timeout).
*/ */
static int tpm_sync(void) static enum cb_err tpm_sync(void)
{ {
struct stopwatch sw; struct stopwatch sw;
stopwatch_init_msecs_expire(&sw, 10); stopwatch_init_msecs_expire(&sw, 10);
while (!tis_plat_irq_status()) { while (!tis_plat_irq_status()) {
if (stopwatch_expired(&sw)) { if (stopwatch_expired(&sw))
printk(BIOS_ERR, "Timeout wait for TPM IRQ!\n"); return CB_ERR;
return 0;
}
} }
return 1;
return CB_SUCCESS;
} }
/* /*
* Each TPM2 SPI transaction starts the same: CS is asserted, the 4 byte * Each TPM2 SPI transaction starts the same: CS is asserted, the 4 byte
* header is sent to the TPM, the master waits til TPM is ready to continue. * header is sent to the TPM, the master waits til TPM is ready to continue.
*
* Returns 1 on success, 0 on failure (TPM SPI flow control timeout.)
*/ */
static int start_transaction(int read_write, size_t bytes, unsigned int addr) static enum cb_err start_transaction(int read_write, size_t bytes, unsigned int addr)
{ {
spi_frame_header header, header_resp; spi_frame_header header, header_resp;
uint8_t byte; uint8_t byte;
@ -128,7 +124,9 @@ static int start_transaction(int read_write, size_t bytes, unsigned int addr)
/* Wait for TPM to finish previous transaction if needed */ /* Wait for TPM to finish previous transaction if needed */
if (tpm_sync_needed) { if (tpm_sync_needed) {
tpm_sync(); if (tpm_sync() != CB_SUCCESS)
printk(BIOS_ERR, "Timeout waiting for TPM IRQ!\n");
/* /*
* During the first invocation of this function on each stage * During the first invocation of this function on each stage
* this if () clause code does not run (as tpm_sync_needed * this if () clause code does not run (as tpm_sync_needed
@ -207,11 +205,11 @@ static int start_transaction(int read_write, size_t bytes, unsigned int addr)
if (ret) { if (ret) {
printk(BIOS_ERR, "SPI-TPM: transfer error\n"); printk(BIOS_ERR, "SPI-TPM: transfer error\n");
spi_release_bus(&spi_slave); spi_release_bus(&spi_slave);
return 0; return CB_ERR;
} }
if (header_resp.body[3] & 1) if (header_resp.body[3] & 1)
return 1; return CB_SUCCESS;
/* /*
* Now poll the bus until TPM removes the stall bit. Give it up to 100 * Now poll the bus until TPM removes the stall bit. Give it up to 100
@ -222,12 +220,12 @@ static int start_transaction(int read_write, size_t bytes, unsigned int addr)
if (stopwatch_expired(&sw)) { if (stopwatch_expired(&sw)) {
printk(BIOS_ERR, "TPM flow control failure\n"); printk(BIOS_ERR, "TPM flow control failure\n");
spi_release_bus(&spi_slave); spi_release_bus(&spi_slave);
return 0; return CB_ERR;
} }
spi_xfer(&spi_slave, NULL, 0, &byte, 1); spi_xfer(&spi_slave, NULL, 0, &byte, 1);
} while (!(byte & 1)); } while (!(byte & 1));
return 1; return CB_SUCCESS;
} }
/* /*
@ -308,48 +306,45 @@ static void read_bytes(void *buffer, size_t bytes)
/* /*
* To write a register, start transaction, transfer data to the TPM, deassert * To write a register, start transaction, transfer data to the TPM, deassert
* CS when done. * CS when done.
*
* Returns one to indicate success, zero to indicate failure.
*/ */
static int tpm2_write_reg(unsigned int reg_number, const void *buffer, size_t bytes) static enum cb_err tpm2_write_reg(unsigned int reg_number, const void *buffer, size_t bytes)
{ {
trace_dump("W", reg_number, bytes, buffer, 0); trace_dump("W", reg_number, bytes, buffer, 0);
if (!start_transaction(false, bytes, reg_number)) if (start_transaction(false, bytes, reg_number) != CB_SUCCESS)
return 0; return CB_ERR;
write_bytes(buffer, bytes); write_bytes(buffer, bytes);
spi_release_bus(&spi_slave); spi_release_bus(&spi_slave);
return 1; return CB_SUCCESS;
} }
/* /*
* To read a register, start transaction, transfer data from the TPM, deassert * To read a register, start transaction, transfer data from the TPM, deassert
* CS when done. * CS when done.
* *
* Returns one to indicate success, zero to indicate failure. In case of * In case of failure zero out the user buffer.
* failure zero out the user buffer.
*/ */
static int tpm2_read_reg(unsigned int reg_number, void *buffer, size_t bytes) static enum cb_err tpm2_read_reg(unsigned int reg_number, void *buffer, size_t bytes)
{ {
if (!start_transaction(true, bytes, reg_number)) { if (start_transaction(true, bytes, reg_number) != CB_SUCCESS) {
memset(buffer, 0, bytes); memset(buffer, 0, bytes);
return 0; return CB_ERR;
} }
read_bytes(buffer, bytes); read_bytes(buffer, bytes);
spi_release_bus(&spi_slave); spi_release_bus(&spi_slave);
trace_dump("R", reg_number, bytes, buffer, 0); trace_dump("R", reg_number, bytes, buffer, 0);
return 1; return CB_SUCCESS;
} }
/* /*
* Status register is accessed often, wrap reading and writing it into * Status register is accessed often, wrap reading and writing it into
* dedicated functions. * dedicated functions.
*/ */
static int read_tpm_sts(uint32_t *status) static enum cb_err read_tpm_sts(uint32_t *status)
{ {
return tpm2_read_reg(TPM_STS_REG, status, sizeof(*status)); return tpm2_read_reg(TPM_STS_REG, status, sizeof(*status));
} }
static int __must_check write_tpm_sts(uint32_t status) static enum cb_err __must_check write_tpm_sts(uint32_t status)
{ {
return tpm2_write_reg(TPM_STS_REG, &status, sizeof(status)); return tpm2_write_reg(TPM_STS_REG, &status, sizeof(status));
} }
@ -383,7 +378,7 @@ static void tpm2_write_access_reg(uint8_t cmd)
tpm2_write_reg(TPM_ACCESS_REG, &cmd, sizeof(cmd)); tpm2_write_reg(TPM_ACCESS_REG, &cmd, sizeof(cmd));
} }
static int tpm2_claim_locality(void) static enum cb_err tpm2_claim_locality(void)
{ {
uint8_t access; uint8_t access;
struct stopwatch sw; struct stopwatch sw;
@ -422,17 +417,18 @@ static int tpm2_claim_locality(void)
printk(BIOS_INFO, "TPM ready after %ld ms\n", printk(BIOS_INFO, "TPM ready after %ld ms\n",
stopwatch_duration_msecs(&sw)); stopwatch_duration_msecs(&sw));
return 1; return CB_SUCCESS;
} while (!stopwatch_expired(&sw)); } while (!stopwatch_expired(&sw));
printk(BIOS_ERR, printk(BIOS_ERR,
"Failed to claim locality 0 after %ld ms, status: %#x\n", "Failed to claim locality 0 after %ld ms, status: %#x\n",
stopwatch_duration_msecs(&sw), access); stopwatch_duration_msecs(&sw), access);
return 0; return CB_ERR;
} }
static int cr50_parse_fw_version(const char *version_str, struct cr50_firmware_version *ver) static enum cb_err cr50_parse_fw_version(const char *version_str,
struct cr50_firmware_version *ver)
{ {
int epoch, major, minor; int epoch, major, minor;
@ -440,33 +436,33 @@ static int cr50_parse_fw_version(const char *version_str, struct cr50_firmware_v
if (!number) if (!number)
number = strstr(version_str, " RW_B:"); number = strstr(version_str, " RW_B:");
if (!number) if (!number)
return -1; return CB_ERR_ARG;
number += 6; /* Skip past the colon. */ number += 6; /* Skip past the colon. */
epoch = skip_atoi(&number); epoch = skip_atoi(&number);
if (*number++ != '.') if (*number++ != '.')
return -2; return CB_ERR_ARG;
major = skip_atoi(&number); major = skip_atoi(&number);
if (*number++ != '.') if (*number++ != '.')
return -2; return CB_ERR_ARG;
minor = skip_atoi(&number); minor = skip_atoi(&number);
ver->epoch = epoch; ver->epoch = epoch;
ver->major = major; ver->major = major;
ver->minor = minor; ver->minor = minor;
return 0; return CB_SUCCESS;
} }
static int cr50_fw_supports_board_cfg(struct cr50_firmware_version *version) static bool cr50_fw_supports_board_cfg(struct cr50_firmware_version *version)
{ {
/* Cr50 supports the CR50_BOARD_CFG register from version 0.5.5 / 0.6.5 /* Cr50 supports the CR50_BOARD_CFG register from version 0.5.5 / 0.6.5
* and onwards. */ * and onwards. */
if (version->epoch > 0 || version->major >= 7 if (version->epoch > 0 || version->major >= 7
|| (version->major >= 5 && version->minor >= 5)) || (version->major >= 5 && version->minor >= 5))
return 1; return true;
printk(BIOS_INFO, "Cr50 firmware does not support CR50_BOARD_CFG, version: %d.%d.%d\n", printk(BIOS_INFO, "Cr50 firmware does not support CR50_BOARD_CFG, version: %d.%d.%d\n",
version->epoch, version->major, version->minor); version->epoch, version->major, version->minor);
return 0; return false;
} }
/** /**
@ -478,7 +474,8 @@ static void cr50_set_board_cfg(void)
if (!cr50_fw_supports_board_cfg(&cr50_firmware_version)) if (!cr50_fw_supports_board_cfg(&cr50_firmware_version))
return; return;
/* Set the CR50_BOARD_CFG register, for e.g. asking cr50 to use longer ready pulses. */ /* Set the CR50_BOARD_CFG register, for e.g. asking cr50 to use longer ready pulses. */
if (!tpm2_read_reg(CR50_BOARD_CFG, &board_cfg_value, sizeof(board_cfg_value))) { if (tpm2_read_reg(CR50_BOARD_CFG, &board_cfg_value, sizeof(board_cfg_value))
!= CB_SUCCESS) {
printk(BIOS_INFO, "Error reading from cr50\n"); printk(BIOS_INFO, "Error reading from cr50\n");
return; return;
} }
@ -499,7 +496,8 @@ static void cr50_set_board_cfg(void)
printk(BIOS_INFO, "Current CR50_BOARD_CFG = 0x%08x, setting to 0x%08x\n", printk(BIOS_INFO, "Current CR50_BOARD_CFG = 0x%08x, setting to 0x%08x\n",
board_cfg_value, CR50_BOARD_CFG_VALUE); board_cfg_value, CR50_BOARD_CFG_VALUE);
board_cfg_value = CR50_BOARD_CFG_VALUE; board_cfg_value = CR50_BOARD_CFG_VALUE;
if (!tpm2_write_reg(CR50_BOARD_CFG, &board_cfg_value, sizeof(board_cfg_value))) if (tpm2_write_reg(CR50_BOARD_CFG, &board_cfg_value, sizeof(board_cfg_value))
!= CB_SUCCESS)
printk(BIOS_INFO, "Error writing to cr50\n"); printk(BIOS_INFO, "Error writing to cr50\n");
} }
@ -512,7 +510,9 @@ static uint32_t cr50_get_board_cfg(void)
uint32_t board_cfg_value; uint32_t board_cfg_value;
if (!cr50_fw_supports_board_cfg(&cr50_firmware_version)) if (!cr50_fw_supports_board_cfg(&cr50_firmware_version))
return 0; return 0;
if (!tpm2_read_reg(CR50_BOARD_CFG, &board_cfg_value, sizeof(board_cfg_value))) {
if (tpm2_read_reg(CR50_BOARD_CFG, &board_cfg_value, sizeof(board_cfg_value))
!= CB_SUCCESS) {
printk(BIOS_INFO, "Error reading from cr50\n"); printk(BIOS_INFO, "Error reading from cr50\n");
return 0; return 0;
} }
@ -530,7 +530,7 @@ static const uint32_t supported_did_vids[] = {
0x0000104a /* ST33HTPH2E32 */ 0x0000104a /* ST33HTPH2E32 */
}; };
static int first_access_this_boot(void) static bool first_access_this_boot(void)
{ {
return ENV_SEPARATE_VERSTAGE || ENV_BOOTBLOCK || !CONFIG(VBOOT); return ENV_SEPARATE_VERSTAGE || ENV_BOOTBLOCK || !CONFIG(VBOOT);
} }
@ -584,10 +584,10 @@ int tpm2_init(struct spi_slave *spi_if)
* Claim locality 0, do it only during the first * Claim locality 0, do it only during the first
* initialization after reset. * initialization after reset.
*/ */
if (!tpm2_claim_locality()) if (tpm2_claim_locality() != CB_SUCCESS)
return -1; return -1;
if (!read_tpm_sts(&status)) { if (read_tpm_sts(&status) != CB_SUCCESS) {
printk(BIOS_ERR, "Reading status reg failed\n"); printk(BIOS_ERR, "Reading status reg failed\n");
return -1; return -1;
} }
@ -635,7 +635,8 @@ int tpm2_init(struct spi_slave *spi_if)
} while (chunk_count * chunk_size < sizeof(version_str) - chunk_size); } while (chunk_count * chunk_size < sizeof(version_str) - chunk_size);
version_str[chunk_count * chunk_size] = '\0'; version_str[chunk_count * chunk_size] = '\0';
printk(BIOS_INFO, "Firmware version: %s\n", version_str); printk(BIOS_INFO, "Firmware version: %s\n", version_str);
if (cr50_parse_fw_version(version_str, &cr50_firmware_version)) {
if (cr50_parse_fw_version(version_str, &cr50_firmware_version) != CB_SUCCESS) {
printk(BIOS_ERR, "Did not recognize Cr50 version format\n"); printk(BIOS_ERR, "Did not recognize Cr50 version format\n");
return -1; return -1;
} }
@ -650,12 +651,9 @@ int tpm2_init(struct spi_slave *spi_if)
/* /*
* This is in seconds, certain TPM commands, like key generation, can take * This is in seconds, certain TPM commands, like key generation, can take
* long time to complete. * long time to complete.
*
* Returns one to indicate success, zero (not yet implemented) to indicate
* failure.
*/ */
#define MAX_STATUS_TIMEOUT 120 #define MAX_STATUS_TIMEOUT 120
static int wait_for_status(uint32_t status_mask, uint32_t status_expected) static enum cb_err wait_for_status(uint32_t status_mask, uint32_t status_expected)
{ {
uint32_t status; uint32_t status;
struct stopwatch sw; struct stopwatch sw;
@ -666,12 +664,12 @@ static int wait_for_status(uint32_t status_mask, uint32_t status_expected)
if (stopwatch_expired(&sw)) { if (stopwatch_expired(&sw)) {
printk(BIOS_ERR, "failed to get expected status %x\n", printk(BIOS_ERR, "failed to get expected status %x\n",
status_expected); status_expected);
return false; return CB_ERR;
} }
read_tpm_sts(&status); read_tpm_sts(&status);
} while ((status & status_mask) != status_expected); } while ((status & status_mask) != status_expected);
return 1; return CB_SUCCESS;
} }
enum fifo_transfer_direction { enum fifo_transfer_direction {
@ -689,9 +687,9 @@ union fifo_transfer_buffer {
* Transfer requested number of bytes to or from TPM FIFO, accounting for the * Transfer requested number of bytes to or from TPM FIFO, accounting for the
* current burst count value. * current burst count value.
*/ */
static int __must_check fifo_transfer(size_t transfer_size, static enum cb_err __must_check fifo_transfer(size_t transfer_size,
union fifo_transfer_buffer buffer, union fifo_transfer_buffer buffer,
enum fifo_transfer_direction direction) enum fifo_transfer_direction direction)
{ {
size_t transaction_size; size_t transaction_size;
size_t burst_count; size_t burst_count;
@ -713,22 +711,22 @@ static int __must_check fifo_transfer(size_t transfer_size,
transaction_size = MIN(transaction_size, 64); transaction_size = MIN(transaction_size, 64);
if (direction == fifo_receive) { if (direction == fifo_receive) {
if (!tpm2_read_reg(TPM_DATA_FIFO_REG, if (tpm2_read_reg(TPM_DATA_FIFO_REG,
buffer.rx_buffer + handled_so_far, buffer.rx_buffer + handled_so_far,
transaction_size)) transaction_size) != CB_SUCCESS)
return 0; return CB_ERR;
} else { } else {
if (!tpm2_write_reg(TPM_DATA_FIFO_REG, if (tpm2_write_reg(TPM_DATA_FIFO_REG,
buffer.tx_buffer + handled_so_far, buffer.tx_buffer + handled_so_far,
transaction_size)) transaction_size) != CB_SUCCESS)
return 0; return CB_ERR;
} }
handled_so_far += transaction_size; handled_so_far += transaction_size;
} while (handled_so_far != transfer_size); } while (handled_so_far != transfer_size);
return 1; return CB_SUCCESS;
} }
size_t tpm2_process_command(const void *tpm2_command, size_t command_size, size_t tpm2_process_command(const void *tpm2_command, size_t command_size,
@ -761,7 +759,7 @@ size_t tpm2_process_command(const void *tpm2_command, size_t command_size,
} }
/* Let the TPM know that the command is coming. */ /* Let the TPM know that the command is coming. */
if (!write_tpm_sts(TPM_STS_COMMAND_READY)) { if (write_tpm_sts(TPM_STS_COMMAND_READY) != CB_SUCCESS) {
printk(BIOS_ERR, "TPM_STS_COMMAND_READY failed\n"); printk(BIOS_ERR, "TPM_STS_COMMAND_READY failed\n");
return 0; return 0;
} }
@ -778,21 +776,21 @@ size_t tpm2_process_command(const void *tpm2_command, size_t command_size,
* burst count or the maximum PDU size, whatever is smaller. * burst count or the maximum PDU size, whatever is smaller.
*/ */
fifo_buffer.tx_buffer = cmd_body; fifo_buffer.tx_buffer = cmd_body;
if (!fifo_transfer(command_size, fifo_buffer, fifo_transmit)) { if (fifo_transfer(command_size, fifo_buffer, fifo_transmit) != CB_SUCCESS) {
printk(BIOS_ERR, "fifo_transfer %zd command bytes failed\n", printk(BIOS_ERR, "fifo_transfer %zd command bytes failed\n",
command_size); command_size);
return 0; return 0;
} }
/* Now tell the TPM it can start processing the command. */ /* Now tell the TPM it can start processing the command. */
if (!write_tpm_sts(TPM_STS_GO)) { if (write_tpm_sts(TPM_STS_GO) != CB_SUCCESS) {
printk(BIOS_ERR, "TPM_STS_GO failed\n"); printk(BIOS_ERR, "TPM_STS_GO failed\n");
return 0; return 0;
} }
/* Now wait for it to report that the response is ready. */ /* Now wait for it to report that the response is ready. */
expected_status_bits = TPM_STS_VALID | TPM_STS_DATA_AVAIL; expected_status_bits = TPM_STS_VALID | TPM_STS_DATA_AVAIL;
if (!wait_for_status(expected_status_bits, expected_status_bits)) { if (wait_for_status(expected_status_bits, expected_status_bits) != CB_SUCCESS) {
/* /*
* If timed out, which should never happen, let's at least * If timed out, which should never happen, let's at least
* print out the offending command. * print out the offending command.
@ -831,7 +829,7 @@ size_t tpm2_process_command(const void *tpm2_command, size_t command_size,
*/ */
bytes_to_go = payload_size - 1 - HEADER_SIZE; bytes_to_go = payload_size - 1 - HEADER_SIZE;
fifo_buffer.rx_buffer = rsp_body + HEADER_SIZE; fifo_buffer.rx_buffer = rsp_body + HEADER_SIZE;
if (!fifo_transfer(bytes_to_go, fifo_buffer, fifo_receive)) { if (fifo_transfer(bytes_to_go, fifo_buffer, fifo_receive) != CB_SUCCESS) {
printk(BIOS_ERR, "fifo_transfer %zd receive bytes failed\n", printk(BIOS_ERR, "fifo_transfer %zd receive bytes failed\n",
bytes_to_go); bytes_to_go);
return 0; return 0;
@ -860,7 +858,7 @@ size_t tpm2_process_command(const void *tpm2_command, size_t command_size,
} }
/* Move the TPM back to idle state. */ /* Move the TPM back to idle state. */
if (!write_tpm_sts(TPM_STS_COMMAND_READY)) { if (write_tpm_sts(TPM_STS_COMMAND_READY) != CB_SUCCESS) {
printk(BIOS_ERR, "TPM_STS_COMMAND_READY failed\n"); printk(BIOS_ERR, "TPM_STS_COMMAND_READY failed\n");
return 0; return 0;
} }