From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomas Winkler Subject: [PATCH 1/3] tpm: cmd_ready command can be issued only after granting locality Date: Tue, 23 Jan 2018 13:27:29 +0200 Message-ID: <20180123112731.3687-1-tomas.winkler@intel.com> Return-path: Sender: owner-linux-security-module@vger.kernel.org To: Jarkko Sakkinen , Jason Gunthorpe Cc: Alexander Usyskin , tpmdd-devel@lists.sourceforge.net, linux-integrity@vger.kernel.org, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, Tomas Winkler List-Id: tpmdd-devel@lists.sourceforge.net The correct sequence is to first request locality and only after that perform cmd_ready handshake, otherwise the hardware will drop the subsequent message as from the device point of view the cmd_ready handshake wasn't performed. Symmetrically locality has to be relinquished only after going idle handshake has completed, this requires that go_idle has to poll for the completion. The issue is only visible on devices that support multiple localities. Signed-off-by: Tomas Winkler --- drivers/char/tpm/tpm-interface.c | 12 ++--- drivers/char/tpm/tpm_crb.c | 95 ++++++++++++++++++++++++++-------------- 2 files changed, 70 insertions(+), 37 deletions(-) diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c index 76df4fbcf089..197fda39aab5 100644 --- a/drivers/char/tpm/tpm-interface.c +++ b/drivers/char/tpm/tpm-interface.c @@ -422,8 +422,6 @@ ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space, if (!(flags & TPM_TRANSMIT_UNLOCKED)) mutex_lock(&chip->tpm_mutex); - if (chip->dev.parent) - pm_runtime_get_sync(chip->dev.parent); if (chip->ops->clk_enable != NULL) chip->ops->clk_enable(chip, true); @@ -439,6 +437,9 @@ ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space, chip->locality = rc; } + if (chip->dev.parent) + pm_runtime_get_sync(chip->dev.parent); + rc = tpm2_prepare_space(chip, space, ordinal, buf); if (rc) goto out; @@ -499,17 +500,18 @@ ssize_t tpm_transmit(struct tpm_chip *chip, struct tpm_space *space, rc = tpm2_commit_space(chip, space, ordinal, buf, &len); out: + if (chip->dev.parent) + pm_runtime_put_sync(chip->dev.parent); + if (need_locality && chip->ops->relinquish_locality) { chip->ops->relinquish_locality(chip, chip->locality); chip->locality = -1; } + out_no_locality: if (chip->ops->clk_enable != NULL) chip->ops->clk_enable(chip, false); - if (chip->dev.parent) - pm_runtime_put_sync(chip->dev.parent); - if (!(flags & TPM_TRANSMIT_UNLOCKED)) mutex_unlock(&chip->tpm_mutex); return rc ? rc : len; diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c index 7b3c2a8aa9de..d174919c446d 100644 --- a/drivers/char/tpm/tpm_crb.c +++ b/drivers/char/tpm/tpm_crb.c @@ -112,6 +112,25 @@ struct tpm2_crb_smc { u32 smc_func_id; }; +static bool crb_wait_for_reg_32(u32 __iomem *reg, u32 mask, u32 value, + unsigned long timeout) +{ + ktime_t start; + ktime_t stop; + + start = ktime_get(); + stop = ktime_add(start, ms_to_ktime(timeout)); + + do { + if ((ioread32(reg) & mask) == value) + return true; + + usleep_range(50, 100); + } while (ktime_before(ktime_get(), stop)); + + return ((ioread32(reg) & mask) == value); +} + /** * crb_go_idle - request tpm crb device to go the idle state * @@ -128,7 +147,7 @@ struct tpm2_crb_smc { * * Return: 0 always */ -static int __maybe_unused crb_go_idle(struct device *dev, struct crb_priv *priv) +static int crb_go_idle(struct device *dev, struct crb_priv *priv) { if ((priv->sm == ACPI_TPM2_START_METHOD) || (priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD) || @@ -136,30 +155,17 @@ static int __maybe_unused crb_go_idle(struct device *dev, struct crb_priv *priv) return 0; iowrite32(CRB_CTRL_REQ_GO_IDLE, &priv->regs_t->ctrl_req); - /* we don't really care when this settles */ + if (!crb_wait_for_reg_32(&priv->regs_t->ctrl_req, + CRB_CTRL_REQ_GO_IDLE/* mask */, + 0, /* value */ + TPM2_TIMEOUT_C)) { + dev_warn(dev, "goIdle timed out\n"); + return -ETIME; + } return 0; } -static bool crb_wait_for_reg_32(u32 __iomem *reg, u32 mask, u32 value, - unsigned long timeout) -{ - ktime_t start; - ktime_t stop; - - start = ktime_get(); - stop = ktime_add(start, ms_to_ktime(timeout)); - - do { - if ((ioread32(reg) & mask) == value) - return true; - - usleep_range(50, 100); - } while (ktime_before(ktime_get(), stop)); - - return false; -} - /** * crb_cmd_ready - request tpm crb device to enter ready state * @@ -175,8 +181,7 @@ static bool crb_wait_for_reg_32(u32 __iomem *reg, u32 mask, u32 value, * * Return: 0 on success -ETIME on timeout; */ -static int __maybe_unused crb_cmd_ready(struct device *dev, - struct crb_priv *priv) +static int crb_cmd_ready(struct device *dev, struct crb_priv *priv) { if ((priv->sm == ACPI_TPM2_START_METHOD) || (priv->sm == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD) || @@ -195,11 +200,11 @@ static int __maybe_unused crb_cmd_ready(struct device *dev, return 0; } -static int crb_request_locality(struct tpm_chip *chip, int loc) +static int __crb_request_locality(struct device *dev, + struct crb_priv *priv, int loc) { - struct crb_priv *priv = dev_get_drvdata(&chip->dev); u32 value = CRB_LOC_STATE_LOC_ASSIGNED | - CRB_LOC_STATE_TPM_REG_VALID_STS; + CRB_LOC_STATE_TPM_REG_VALID_STS; if (!priv->regs_h) return 0; @@ -207,23 +212,36 @@ static int crb_request_locality(struct tpm_chip *chip, int loc) iowrite32(CRB_LOC_CTRL_REQUEST_ACCESS, &priv->regs_h->loc_ctrl); if (!crb_wait_for_reg_32(&priv->regs_h->loc_state, value, value, TPM2_TIMEOUT_C)) { - dev_warn(&chip->dev, "TPM_LOC_STATE_x.requestAccess timed out\n"); + dev_warn(dev, "TPM_LOC_STATE_x.requestAccess timed out\n"); return -ETIME; } return 0; } -static void crb_relinquish_locality(struct tpm_chip *chip, int loc) +static int crb_request_locality(struct tpm_chip *chip, int loc) { struct crb_priv *priv = dev_get_drvdata(&chip->dev); + return __crb_request_locality(&chip->dev, priv, loc); +} + +static void __crb_relinquish_locality(struct device *dev, + struct crb_priv *priv, int loc) +{ if (!priv->regs_h) return; iowrite32(CRB_LOC_CTRL_RELINQUISH, &priv->regs_h->loc_ctrl); } +static void crb_relinquish_locality(struct tpm_chip *chip, int loc) +{ + struct crb_priv *priv = dev_get_drvdata(&chip->dev); + + __crb_relinquish_locality(&chip->dev, priv, loc); +} + static u8 crb_status(struct tpm_chip *chip) { struct crb_priv *priv = dev_get_drvdata(&chip->dev); @@ -475,6 +493,10 @@ static int crb_map_io(struct acpi_device *device, struct crb_priv *priv, dev_warn(dev, FW_BUG "Bad ACPI memory layout"); } + ret = __crb_request_locality(dev, priv, 0); + if (ret) + return ret; + priv->regs_t = crb_map_res(dev, priv, &io_res, buf->control_address, sizeof(struct crb_regs_tail)); if (IS_ERR(priv->regs_t)) @@ -531,6 +553,8 @@ static int crb_map_io(struct acpi_device *device, struct crb_priv *priv, crb_go_idle(dev, priv); + __crb_relinquish_locality(dev, priv, 0); + return ret; } @@ -588,10 +612,14 @@ static int crb_acpi_add(struct acpi_device *device) chip->acpi_dev_handle = device->handle; chip->flags = TPM_CHIP_FLAG_TPM2; - rc = crb_cmd_ready(dev, priv); + rc = __crb_request_locality(dev, priv, 0); if (rc) return rc; + rc = crb_cmd_ready(dev, priv); + if (rc) + goto out; + pm_runtime_get_noresume(dev); pm_runtime_set_active(dev); pm_runtime_enable(dev); @@ -601,12 +629,15 @@ static int crb_acpi_add(struct acpi_device *device) crb_go_idle(dev, priv); pm_runtime_put_noidle(dev); pm_runtime_disable(dev); - return rc; + goto out; } - pm_runtime_put(dev); + pm_runtime_put_sync(dev); - return 0; +out: + __crb_relinquish_locality(dev, priv, 0); + + return rc; } static int crb_acpi_remove(struct acpi_device *device) -- 2.14.3