lkml.org 
[lkml]   [2018]   [May]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] tpm: separate cmd_ready/go_idle from runtime_pm
Date
We cannot use go_idle cmd_ready commands via runtime_pm handles
as with the introduction of localities this is no longer an optional
feature, while runtime pm can be not enabled.
Though cmd_ready/go_idle provides a power saving, it's also a part of
TPM2 protocol and should be called explicitly.
This patch exposes cmd_read/go_idle via tpm class ops and removes
runtime pm support as it is not used by any driver.
New wrappers are added tpm_cmd_ready() and tpm_go_idle() wrappers to
streamline tpm_try_transmit code. TPM_TRANSMIT_UNLOCKED flag is abused to
resolve tpm spaces recursive calls to tpm_transmit().

tpm_crb no longer needs own power saving functions and can drop using
tpm_pm_suspend/resume.

This patch cannot be really spearated from the locality fix.
Fixes: 888d867df441 (tpm: cmd_ready command can be issued only after granting locality)


Fixes: 888d867df441 (tpm: cmd_ready command can be issued only after granting locality)
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
---
V2:resent
V3:resent
V4: 1. Use tpm_pm_suspend/resume in tpm_crb
2. Drop cmd_ready/go_idle around tpm_chip_register, as there is no
usage counter like in runtime_pm.
V5: 1. add tpm_cmd_ready and tpm_go_idle wrappers.
2. Abuse TPM_TRANSMIT_UNLOCKED flag to resolve tpm space
recursion.
drivers/char/tpm/tpm-interface.c | 33 +++++++++++--
drivers/char/tpm/tpm_crb.c | 101 +++++++++++----------------------------
include/linux/tpm.h | 2 +
3 files changed, 57 insertions(+), 79 deletions(-)

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index e32f6e85dc6d..f802d4ee918c 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -29,7 +29,6 @@
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/freezer.h>
-#include <linux/pm_runtime.h>
#include <linux/tpm_eventlog.h>

#include "tpm.h"
@@ -399,6 +398,28 @@ static void tpm_relinquish_locality(struct tpm_chip *chip)
chip->locality = -1;
}

+static int tpm_cmd_ready(struct tpm_chip *chip, unsigned int flags)
+{
+ if (flags & TPM_TRANSMIT_UNLOCKED)
+ return 0;
+
+ if (!chip->ops->cmd_ready)
+ return 0;
+
+ return chip->ops->cmd_ready(chip);
+}
+
+static int tpm_go_idle(struct tpm_chip *chip, unsigned int flags)
+{
+ if (flags & TPM_TRANSMIT_UNLOCKED)
+ return 0;
+
+ if (!chip->ops->go_idle)
+ return 0;
+
+ return chip->ops->go_idle(chip);
+}
+
static ssize_t tpm_try_transmit(struct tpm_chip *chip,
struct tpm_space *space,
u8 *buf, size_t bufsiz,
@@ -455,8 +476,9 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip,
goto out_no_locality;
}

- if (chip->dev.parent)
- pm_runtime_get_sync(chip->dev.parent);
+ rc = tpm_cmd_ready(chip, flags);
+ if (rc)
+ goto out;

rc = tpm2_prepare_space(chip, space, ordinal, buf);
if (rc)
@@ -518,8 +540,9 @@ static ssize_t tpm_try_transmit(struct tpm_chip *chip,
rc = tpm2_commit_space(chip, space, ordinal, buf, &len);

out:
- if (chip->dev.parent)
- pm_runtime_put_sync(chip->dev.parent);
+ rc = tpm_go_idle(chip, flags);
+ if (rc)
+ goto out;

if (need_locality)
tpm_relinquish_locality(chip);
diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
index 34fbc6cb097b..36952ef98f90 100644
--- a/drivers/char/tpm/tpm_crb.c
+++ b/drivers/char/tpm/tpm_crb.c
@@ -132,7 +132,7 @@ static bool crb_wait_for_reg_32(u32 __iomem *reg, u32 mask, u32 value,
}

/**
- * crb_go_idle - request tpm crb device to go the idle state
+ * __crb_go_idle - request tpm crb device to go the idle state
*
* @dev: crb device
* @priv: crb private data
@@ -147,7 +147,7 @@ static bool crb_wait_for_reg_32(u32 __iomem *reg, u32 mask, u32 value,
*
* Return: 0 always
*/
-static int 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) ||
@@ -163,11 +163,20 @@ static int crb_go_idle(struct device *dev, struct crb_priv *priv)
dev_warn(dev, "goIdle timed out\n");
return -ETIME;
}
+
return 0;
}

+static int crb_go_idle(struct tpm_chip *chip)
+{
+ struct device *dev = &chip->dev;
+ struct crb_priv *priv = dev_get_drvdata(dev);
+
+ return __crb_go_idle(dev, priv);
+}
+
/**
- * crb_cmd_ready - request tpm crb device to enter ready state
+ * __crb_cmd_ready - request tpm crb device to enter ready state
*
* @dev: crb device
* @priv: crb private data
@@ -181,7 +190,7 @@ static int crb_go_idle(struct device *dev, struct crb_priv *priv)
*
* Return: 0 on success -ETIME on timeout;
*/
-static int 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) ||
@@ -200,6 +209,14 @@ static int crb_cmd_ready(struct device *dev, struct crb_priv *priv)
return 0;
}

+static int crb_cmd_ready(struct tpm_chip *chip)
+{
+ struct device *dev = &chip->dev;
+ struct crb_priv *priv = dev_get_drvdata(dev);
+
+ return __crb_cmd_ready(dev, priv);
+}
+
static int __crb_request_locality(struct device *dev,
struct crb_priv *priv, int loc)
{
@@ -401,6 +418,8 @@ static const struct tpm_class_ops tpm_crb = {
.send = crb_send,
.cancel = crb_cancel,
.req_canceled = crb_req_canceled,
+ .go_idle = crb_go_idle,
+ .cmd_ready = crb_cmd_ready,
.request_locality = crb_request_locality,
.relinquish_locality = crb_relinquish_locality,
.req_complete_mask = CRB_DRV_STS_COMPLETE,
@@ -520,7 +539,7 @@ static int crb_map_io(struct acpi_device *device, struct crb_priv *priv,
* PTT HW bug w/a: wake up the device to access
* possibly not retained registers.
*/
- ret = crb_cmd_ready(dev, priv);
+ ret = __crb_cmd_ready(dev, priv);
if (ret)
goto out_relinquish_locality;

@@ -565,7 +584,7 @@ static int crb_map_io(struct acpi_device *device, struct crb_priv *priv,
if (!ret)
priv->cmd_size = cmd_size;

- crb_go_idle(dev, priv);
+ __crb_go_idle(dev, priv);

out_relinquish_locality:

@@ -628,32 +647,7 @@ static int crb_acpi_add(struct acpi_device *device)
chip->acpi_dev_handle = device->handle;
chip->flags = TPM_CHIP_FLAG_TPM2;

- 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);
-
- rc = tpm_chip_register(chip);
- if (rc) {
- crb_go_idle(dev, priv);
- pm_runtime_put_noidle(dev);
- pm_runtime_disable(dev);
- goto out;
- }
-
- pm_runtime_put_sync(dev);
-
-out:
- __crb_relinquish_locality(dev, priv, 0);
-
- return rc;
+ return tpm_chip_register(chip);
}

static int crb_acpi_remove(struct acpi_device *device)
@@ -663,52 +657,11 @@ static int crb_acpi_remove(struct acpi_device *device)

tpm_chip_unregister(chip);

- pm_runtime_disable(dev);
-
return 0;
}

-static int __maybe_unused crb_pm_runtime_suspend(struct device *dev)
-{
- struct tpm_chip *chip = dev_get_drvdata(dev);
- struct crb_priv *priv = dev_get_drvdata(&chip->dev);
-
- return crb_go_idle(dev, priv);
-}
-
-static int __maybe_unused crb_pm_runtime_resume(struct device *dev)
-{
- struct tpm_chip *chip = dev_get_drvdata(dev);
- struct crb_priv *priv = dev_get_drvdata(&chip->dev);
-
- return crb_cmd_ready(dev, priv);
-}
-
-static int __maybe_unused crb_pm_suspend(struct device *dev)
-{
- int ret;
-
- ret = tpm_pm_suspend(dev);
- if (ret)
- return ret;
-
- return crb_pm_runtime_suspend(dev);
-}
-
-static int __maybe_unused crb_pm_resume(struct device *dev)
-{
- int ret;
-
- ret = crb_pm_runtime_resume(dev);
- if (ret)
- return ret;
-
- return tpm_pm_resume(dev);
-}
-
static const struct dev_pm_ops crb_pm = {
- SET_SYSTEM_SLEEP_PM_OPS(crb_pm_suspend, crb_pm_resume)
- SET_RUNTIME_PM_OPS(crb_pm_runtime_suspend, crb_pm_runtime_resume, NULL)
+ SET_SYSTEM_SLEEP_PM_OPS(tpm_pm_suspend, tpm_pm_resume)
};

static const struct acpi_device_id crb_device_ids[] = {
diff --git a/include/linux/tpm.h b/include/linux/tpm.h
index 06639fb6ab85..8eb5e5ebe136 100644
--- a/include/linux/tpm.h
+++ b/include/linux/tpm.h
@@ -43,6 +43,8 @@ struct tpm_class_ops {
u8 (*status) (struct tpm_chip *chip);
bool (*update_timeouts)(struct tpm_chip *chip,
unsigned long *timeout_cap);
+ int (*go_idle)(struct tpm_chip *chip);
+ int (*cmd_ready)(struct tpm_chip *chip);
int (*request_locality)(struct tpm_chip *chip, int loc);
int (*relinquish_locality)(struct tpm_chip *chip, int loc);
void (*clk_enable)(struct tpm_chip *chip, bool value);
--
2.14.3
\
 
 \ /
  Last update: 2018-05-16 22:52    [W:0.077 / U:0.772 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site