On Fri, Mar 17, 2017 at 06:43:13PM -0500, Jiandi An wrote:
> 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]>
Does not compile.
/Jarkko
> ---
> 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.
>
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