This enables TPM Command Response Buffer interface driver for ARM64 and implements an ARM specific TPM CRB start method that invokes a Secure Monitor Call (SMC) to request the TrustZone Firmware to execute or cancel a TPM 2.0 command.
In ARM, TrustZone security extensions enable a secure software environment with Secure Monitor mode. A Secure Monitor Call (SMC) is used to enter the Secure Monitor mode and perform a Secure Monitor service to communicate with TrustZone firmware which has control over the TPM hardware. Signed-off-by: Jiandi An <[email protected]> --- drivers/char/tpm/Kconfig | 2 +- drivers/char/tpm/tpm_crb.c | 64 ++++++++++++++++++++++++++++++++++++++++++++-- 2 files changed, 63 insertions(+), 3 deletions(-) diff --git a/drivers/char/tpm/Kconfig b/drivers/char/tpm/Kconfig index d520ac5..a3035220 100644 --- a/drivers/char/tpm/Kconfig +++ b/drivers/char/tpm/Kconfig @@ -136,7 +136,7 @@ config TCG_XEN config TCG_CRB tristate "TPM 2.0 CRB Interface" - depends on X86 && ACPI + depends on ACPI ---help--- If you have a TPM security chip that is compliant with the TCG CRB 2.0 TPM specification say Yes and it will be accessible diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c index cb6fb13..f8a5470 100644 --- a/drivers/char/tpm/tpm_crb.c +++ b/drivers/char/tpm/tpm_crb.c @@ -20,6 +20,9 @@ #include <linux/rculist.h> #include <linux/module.h> #include <linux/pm_runtime.h> +#ifdef CONFIG_ARM64 +#include <linux/arm-smccc.h> +#endif #include "tpm.h" #define ACPI_SIG_TPM2 "TPM2" @@ -73,6 +76,7 @@ enum crb_status { enum crb_flags { CRB_FL_ACPI_START = BIT(0), CRB_FL_CRB_START = BIT(1), + CRB_FL_CRB_SMC_START = BIT(2), }; struct crb_priv { @@ -82,6 +86,15 @@ struct crb_priv { u8 __iomem *cmd; u8 __iomem *rsp; u32 cmd_size; + u32 smc_func_id; +}; + +struct tpm2_crb_smc { + u32 interrupt; + u8 interrupt_flags; + u8 op_flags; + u16 reserved2; + u32 smc_func_id; }; /** @@ -101,7 +114,8 @@ struct crb_priv { */ static int __maybe_unused crb_go_idle(struct device *dev, struct crb_priv *priv) { - if (priv->flags & CRB_FL_ACPI_START) + if ((priv->flags & CRB_FL_ACPI_START) || + (priv->flags & CRB_FL_CRB_SMC_START)) return 0; iowrite32(CRB_CTRL_REQ_GO_IDLE, &priv->cca->req); @@ -129,7 +143,8 @@ static int __maybe_unused crb_cmd_ready(struct device *dev, { ktime_t stop, start; - if (priv->flags & CRB_FL_ACPI_START) + if ((priv->flags & CRB_FL_ACPI_START) || + (priv->flags & CRB_FL_CRB_SMC_START)) return 0; iowrite32(CRB_CTRL_REQ_CMD_READY, &priv->cca->req); @@ -202,6 +217,33 @@ static int crb_do_acpi_start(struct tpm_chip *chip) return rc; } +#ifdef CONFIG_ARM64 +/* + * This is a TPM Command Response Buffer start method that invokes a + * Secure Monitor Call to requrest the firmware to execute or cancel + * a TPM 2.0 command. + */ +static inline int tpm_crb_smc_start(struct device *dev, unsigned long func_id) +{ + struct arm_smccc_res res; + + arm_smccc_smc(func_id, 0, 0, 0, 0, 0, 0, 0, &res); + if (res.a0 != 0) { + dev_err(dev, FW_BUG "tpm_crb_smc_start() returns res.a0 = 0x%lx\n", + res.a0); + return -EIO; + } + + return 0; +} +#else +static inline int tpm_crb_smc_start(struct device *dev, unsigned long func_id) +{ + dev_err(dev, FW_BUG "tpm_crb: incorrect start method\n"); + return -EINVAL; +} +#endif + static int crb_send(struct tpm_chip *chip, u8 *buf, size_t len) { struct crb_priv *priv = dev_get_drvdata(&chip->dev); @@ -229,6 +271,11 @@ static int crb_send(struct tpm_chip *chip, u8 *buf, size_t len) if (priv->flags & CRB_FL_ACPI_START) rc = crb_do_acpi_start(chip); + if (priv->flags & CRB_FL_CRB_SMC_START) { + iowrite32(CRB_START_INVOKE, &priv->cca->start); + rc = tpm_crb_smc_start(&chip->dev, priv->smc_func_id); + } + return rc; } @@ -409,6 +456,7 @@ static int crb_acpi_add(struct acpi_device *device) struct crb_priv *priv; struct tpm_chip *chip; struct device *dev = &device->dev; + struct tpm2_crb_smc *crb_smc; acpi_status status; u32 sm; int rc; @@ -441,6 +489,18 @@ static int crb_acpi_add(struct acpi_device *device) sm == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD) priv->flags |= CRB_FL_ACPI_START; + if (sm == ACPI_TPM2_COMMAND_BUFFER_WITH_SMC) { + if (buf->header.length < (sizeof(*buf) + sizeof(*crb_smc))) { + dev_err(dev, FW_BUG "TPM2 ACPI table has wrong size %u for start method type %d\n", + buf->header.length, ACPI_TPM2_COMMAND_BUFFER_WITH_SMC); + return -EINVAL; + } + crb_smc = (struct tpm2_crb_smc *) (((u8 *) buf) + + ACPI_TPM2_START_METHOD_PARAMETER_OFFSET); + priv->smc_func_id = crb_smc->smc_func_id; + priv->flags |= CRB_FL_CRB_SMC_START; + } + rc = crb_map_io(device, priv, buf); if (rc) return rc; -- Jiandi An Qualcomm Datacenter Technologies, Inc. as an affiliate of Qualcomm Technologies, Inc. Qualcomm Technologies, Inc. is a member of the Code Aurora Forum, a Linux Foundation Collaborative Project. ------------------------------------------------------------------------------ Check out the vibrant tech community on one of the world's most engaging tech sites, Slashdot.org! http://sdm.link/slashdot _______________________________________________ tpmdd-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/tpmdd-devel
