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Date: Wed, 6 Sep 2017 15:39:02 +0300
From: Jarkko Sakkinen <jarkko.sakkinen@...ux.intel.com>
To: Jiandi An <anjiandi@...eaurora.org>
Cc: peterhuewe@....de, tpmdd@...horst.net,
jgunthorpe@...idianresearch.com, tpmdd-devel@...ts.sourceforge.net,
linux-kernel@...r.kernel.org
Subject: Re: [PATCH] tpm/tpm_crb: Use start method value from ACPI table
directly
On Fri, Aug 25, 2017 at 06:28:55PM -0500, Jiandi An wrote:
> This patch gets rid of dealing with intermediate flag for start method
> and use start method value from ACPI table directly.
>
> For ARM64, the locality is handled by Trust Zone in FW. The layout
> does not have crb_regs_head. It is hitting the following line.
> dev_warn(dev, FW_BUG "Bad ACPI memory layout");
>
> Current code excludes CRB_FL_ACPI_START for this check. Now since
> ARM64 support for TPM CRB is added, CRB_FL_CRB_SMC_START should also be
> excluded from this check.
>
> For goIdle and cmdReady where code was excluding CRB_FL_ACPI_START only
> (do nothing for ACPI start method), CRB_FL_CRB_SMC_START was also
> excluded as ARM64 SMC start method does not have TPM_CRB_CTRL_REQ.
>
> However with special PPT workaround requiring CRB_FL_CRB_START to be
> set in addition to CRB_FL_ACPI_START and the addition flag of SMC
> start method CRB_FL_CRB_SMC_START, the code has become difficult to
> maintain and undrestand. It is better to make code deal with start
> method value from ACPI table directly.
>
> Signed-off-by: Jiandi An <anjiandi@...eaurora.org>
> ---
> drivers/char/tpm/tpm_crb.c | 59 +++++++++++++++++++++++-----------------------
> 1 file changed, 29 insertions(+), 30 deletions(-)
>
> diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
> index 8f0a98d..7b3c2a8 100644
> --- a/drivers/char/tpm/tpm_crb.c
> +++ b/drivers/char/tpm/tpm_crb.c
> @@ -92,14 +92,9 @@ enum crb_status {
> CRB_DRV_STS_COMPLETE = BIT(0),
> };
>
> -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 {
> - unsigned int flags;
> + u32 sm;
> + const char *hid;
> void __iomem *iobase;
> struct crb_regs_head __iomem *regs_h;
> struct crb_regs_tail __iomem *regs_t;
> @@ -128,14 +123,16 @@ struct tpm2_crb_smc {
> * Anyhow, we do not wait here as a consequent CMD_READY request
> * will be handled correctly even if idle was not completed.
> *
> - * The function does nothing for devices with ACPI-start method.
> + * The function does nothing for devices with ACPI-start method
> + * or SMC-start method.
> *
> * Return: 0 always
> */
> static int __maybe_unused crb_go_idle(struct device *dev, struct crb_priv *priv)
> {
> - if ((priv->flags & CRB_FL_ACPI_START) ||
> - (priv->flags & CRB_FL_CRB_SMC_START))
> + if ((priv->sm == ACPI_TPM2_START_METHOD) ||
> + (priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD) ||
> + (priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_ARM_SMC))
> return 0;
>
> iowrite32(CRB_CTRL_REQ_GO_IDLE, &priv->regs_t->ctrl_req);
> @@ -174,14 +171,16 @@ static bool crb_wait_for_reg_32(u32 __iomem *reg, u32 mask, u32 value,
> * The device should respond within TIMEOUT_C.
> *
> * The function does nothing for devices with ACPI-start method
> + * or SMC-start method.
> *
> * Return: 0 on success -ETIME on timeout;
> */
> static int __maybe_unused crb_cmd_ready(struct device *dev,
> struct crb_priv *priv)
> {
> - if ((priv->flags & CRB_FL_ACPI_START) ||
> - (priv->flags & CRB_FL_CRB_SMC_START))
> + if ((priv->sm == ACPI_TPM2_START_METHOD) ||
> + (priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD) ||
> + (priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_ARM_SMC))
> return 0;
>
> iowrite32(CRB_CTRL_REQ_CMD_READY, &priv->regs_t->ctrl_req);
> @@ -325,13 +324,20 @@ static int crb_send(struct tpm_chip *chip, u8 *buf, size_t len)
> /* Make sure that cmd is populated before issuing start. */
> wmb();
>
> - if (priv->flags & CRB_FL_CRB_START)
> + /* The reason for the extra quirk is that the PTT in 4th Gen Core CPUs
> + * report only ACPI start but in practice seems to require both
> + * CRB start, hence invoking CRB start method if hid == MSFT0101.
> + */
> + if ((priv->sm == ACPI_TPM2_COMMAND_BUFFER) ||
> + (priv->sm == ACPI_TPM2_MEMORY_MAPPED) ||
> + (!strcmp(priv->hid, "MSFT0101")))
> iowrite32(CRB_START_INVOKE, &priv->regs_t->ctrl_start);
>
> - if (priv->flags & CRB_FL_ACPI_START)
> + if ((priv->sm == ACPI_TPM2_START_METHOD) ||
> + (priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD))
> rc = crb_do_acpi_start(chip);
>
> - if (priv->flags & CRB_FL_CRB_SMC_START) {
> + if (priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_ARM_SMC) {
> iowrite32(CRB_START_INVOKE, &priv->regs_t->ctrl_start);
> rc = tpm_crb_smc_start(&chip->dev, priv->smc_func_id);
> }
> @@ -345,7 +351,9 @@ static void crb_cancel(struct tpm_chip *chip)
>
> iowrite32(CRB_CANCEL_INVOKE, &priv->regs_t->ctrl_cancel);
>
> - if ((priv->flags & CRB_FL_ACPI_START) && crb_do_acpi_start(chip))
> + if (((priv->sm == ACPI_TPM2_START_METHOD) ||
> + (priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD)) &&
> + crb_do_acpi_start(chip))
> dev_err(&chip->dev, "ACPI Start failed\n");
> }
>
> @@ -458,7 +466,8 @@ static int crb_map_io(struct acpi_device *device, struct crb_priv *priv,
> * the control area, as one nice sane region except for some older
> * stuff that puts the control area outside the ACPI IO region.
> */
> - if (!(priv->flags & CRB_FL_ACPI_START)) {
> + if ((priv->sm == ACPI_TPM2_COMMAND_BUFFER) ||
> + (priv->sm == ACPI_TPM2_MEMORY_MAPPED)) {
> if (buf->control_address == io_res.start +
> sizeof(*priv->regs_h))
> priv->regs_h = priv->iobase;
> @@ -552,18 +561,6 @@ static int crb_acpi_add(struct acpi_device *device)
> if (!priv)
> return -ENOMEM;
>
> - /* The reason for the extra quirk is that the PTT in 4th Gen Core CPUs
> - * report only ACPI start but in practice seems to require both
> - * ACPI start and CRB start.
> - */
> - if (sm == ACPI_TPM2_COMMAND_BUFFER || sm == ACPI_TPM2_MEMORY_MAPPED ||
> - !strcmp(acpi_device_hid(device), "MSFT0101"))
> - priv->flags |= CRB_FL_CRB_START;
> -
> - if (sm == ACPI_TPM2_START_METHOD ||
> - sm == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD)
> - priv->flags |= CRB_FL_ACPI_START;
> -
> if (sm == ACPI_TPM2_COMMAND_BUFFER_WITH_ARM_SMC) {
> if (buf->header.length < (sizeof(*buf) + sizeof(*crb_smc))) {
> dev_err(dev,
> @@ -574,9 +571,11 @@ static int crb_acpi_add(struct acpi_device *device)
> }
> crb_smc = ACPI_ADD_PTR(struct tpm2_crb_smc, buf, sizeof(*buf));
> priv->smc_func_id = crb_smc->smc_func_id;
> - priv->flags |= CRB_FL_CRB_SMC_START;
> }
>
> + priv->sm = sm;
> + priv->hid = acpi_device_hid(device);
> +
> 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.
Tested-by: Jarkko Sakkinen <jarkko.sakkine@...ux.intel.com>
I run smoke test suite [1]:
$ python -m unittest -v tpm2_smoke
test_seal_with_auth (tpm2_smoke.SmokeTest) ... ok
test_seal_with_policy (tpm2_smoke.SmokeTest) ... ok
test_seal_with_too_long_auth (tpm2_smoke.SmokeTest) ... ok
test_unseal_with_wrong_auth (tpm2_smoke.SmokeTest) ... ok
test_unseal_with_wrong_policy (tpm2_smoke.SmokeTest) ... ok
test_flush_context (tpm2_smoke.SpaceTest) ... ok
test_get_handles (tpm2_smoke.SpaceTest) ... ok
test_make_two_spaces (tpm2_smoke.SpaceTest) ... ok
----------------------------------------------------------------------
Ran 8 tests in 25.816s
OK
This doesn't verify that things work on ARM64 because for that I do not
pose a test platform. However, since tpm_crb is not in wide use yet on
that platform I do not think it matters. And the code changes do not
have huge potential to cause collateral damage even if they were broken
on that platform.
[1] https://github.com/jsakkine-intel/tpm2-scripts
/Jarkko
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