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tpm/tpm_crb: Enable TPM CRB interface for ARM64

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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 <anjiandi@codeaurora.org>
Tested-by: Shanker Donthineni <shankerd@codeaurora.org>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> (on x86/PTT)
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
This commit is contained in:
Jiandi An 2017-03-24 04:55:45 -05:00 committed by Jarkko Sakkinen
parent cf8252ca7c
commit 08eff49d63
2 changed files with 66 additions and 3 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
drivers/char/tpm/Kconfig
View File

@ -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

67
drivers/char/tpm/tpm_crb.c
View File

@ -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"
@ -93,6 +96,7 @@ 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 {
@ -103,6 +107,15 @@ 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;
};
/**
@ -122,7 +135,8 @@ 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->regs_t->ctrl_req);
@ -167,7 +181,8 @@ static bool crb_wait_for_reg_32(u32 __iomem *reg, u32 mask, u32 value,
static int __maybe_unused crb_cmd_ready(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_CMD_READY, &priv->regs_t->ctrl_req);
@ -262,6 +277,34 @@ 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 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 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);
@ -289,6 +332,11 @@ 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->regs_t->ctrl_start);
rc = tpm_crb_smc_start(&chip->dev, priv->smc_func_id);
}
return rc;
}
@ -483,6 +531,7 @@ 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;
@ -515,6 +564,20 @@ 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 = ACPI_ADD_PTR(struct tpm2_crb_smc, 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;