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Date: Wed, 8 Jun 2016 02:02:02 +0300
From: Jarkko Sakkinen <jarkko.sakkinen@...ux.intel.com>
To: Peter Huewe <peterhuewe@....de>
Cc: linux-security-module@...r.kernel.org,
Jarkko Sakkinen <jarkko.sakkinen@...ux.intel.com>,
Marcel Selhorst <tpmdd@...horst.net>,
Jason Gunthorpe <jgunthorpe@...idianresearch.com>,
tpmdd-devel@...ts.sourceforge.net (moderated list:TPM DEVICE DRIVER),
linux-kernel@...r.kernel.org (open list)
Subject: [PATCH 3/3] tpm, tpm_crb: runtime power management
The register TPM_CRB_CTRL_REQ_0 contains bits goIdle and cmdReady for
invoking the chip to suspend and resume. This commit implements runtime
PM for tpm_crb by using these bits.
The legacy ACPI start (SMI + DMA) based devices do not support these
bits. Thus this functionality only is enabled only for CRB start (MMIO)
based devices.
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@...ux.intel.com>
---
drivers/char/tpm/tpm-interface.c | 3 ++
drivers/char/tpm/tpm_crb.c | 62 ++++++++++++++++++++++++++++++++++++++--
2 files changed, 63 insertions(+), 2 deletions(-)
diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index 5e3c1b6..3b85648 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -29,6 +29,7 @@
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/freezer.h>
+#include <linux/pm_runtime.h>
#include "tpm.h"
#include "tpm_eventlog.h"
@@ -350,6 +351,7 @@ ssize_t tpm_transmit(struct tpm_chip *chip, const char *buf,
return -E2BIG;
}
+ pm_runtime_get_sync(chip->dev.parent);
mutex_lock(&chip->tpm_mutex);
rc = chip->ops->send(chip, (u8 *) buf, count);
@@ -394,6 +396,7 @@ out_recv:
"tpm_transmit: tpm_recv: error %zd\n", rc);
out:
mutex_unlock(&chip->tpm_mutex);
+ pm_runtime_put_sync(chip->dev.parent);
return rc;
}
diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
index ca2cad9..71cc7cd 100644
--- a/drivers/char/tpm/tpm_crb.c
+++ b/drivers/char/tpm/tpm_crb.c
@@ -20,6 +20,7 @@
#include <linux/rculist.h>
#include <linux/module.h>
#include <linux/platform_device.h>
+#include <linux/pm_runtime.h>
#include "tpm.h"
#define ACPI_SIG_TPM2 "TPM2"
@@ -41,7 +42,6 @@ enum crb_ca_request {
enum crb_ca_status {
CRB_CA_STS_ERROR = BIT(0),
- CRB_CA_STS_TPM_IDLE = BIT(1),
};
enum crb_start {
@@ -68,6 +68,8 @@ struct crb_control_area {
enum crb_status {
CRB_STS_COMPLETE = BIT(0),
+ CRB_STS_READY = BIT(1),
+ CRB_STS_IDLE = BIT(2),
};
enum crb_flags {
@@ -81,9 +83,52 @@ struct crb_priv {
struct crb_control_area __iomem *cca;
u8 __iomem *cmd;
u8 __iomem *rsp;
+ wait_queue_head_t idle_queue;
};
-static SIMPLE_DEV_PM_OPS(crb_pm, tpm_pm_suspend, tpm_pm_resume);
+static int __maybe_unused crb_runtime_suspend(struct device *dev)
+{
+ struct tpm_chip *chip = dev_get_drvdata(dev);
+ struct crb_priv *priv = dev_get_drvdata(&chip->dev);
+ u32 req;
+
+ if (priv->flags & CRB_FL_ACPI_START)
+ return 0;
+
+ req = ioread32(&priv->cca->req);
+
+ iowrite32(cpu_to_le32(req | CRB_CA_REQ_GO_IDLE), &priv->cca->req);
+
+ if (wait_for_tpm_stat(chip, CRB_STS_IDLE, chip->timeout_c,
+ &priv->idle_queue, false))
+ dev_warn(&chip->dev, "idle timed out\n");
+
+ return 0;
+}
+
+static int __maybe_unused crb_runtime_resume(struct device *dev)
+{
+ struct tpm_chip *chip = dev_get_drvdata(dev);
+ struct crb_priv *priv = dev_get_drvdata(&chip->dev);
+ u32 req;
+
+ if (priv->flags & CRB_FL_ACPI_START)
+ return 0;
+
+ req = ioread32(&priv->cca->req);
+ iowrite32(cpu_to_le32(req | CRB_CA_REQ_CMD_READY), &priv->cca->req);
+
+ if (wait_for_tpm_stat(chip, CRB_STS_READY, chip->timeout_c,
+ &priv->idle_queue, false))
+ dev_warn(&chip->dev, "wake timed out\n");
+
+ return 0;
+}
+
+static const struct dev_pm_ops crb_pm = {
+ SET_RUNTIME_PM_OPS(crb_runtime_suspend, crb_runtime_resume, NULL)
+ SET_SYSTEM_SLEEP_PM_OPS(tpm_pm_suspend, tpm_pm_resume)
+};
static u8 crb_status(struct tpm_chip *chip)
{
@@ -94,6 +139,14 @@ static u8 crb_status(struct tpm_chip *chip)
CRB_START_INVOKE)
sts |= CRB_STS_COMPLETE;
+ if ((ioread32(&priv->cca->req) & CRB_CA_REQ_CMD_READY) !=
+ CRB_CA_REQ_CMD_READY)
+ sts |= CRB_STS_READY;
+
+ if ((ioread32(&priv->cca->req) & CRB_CA_REQ_GO_IDLE) !=
+ CRB_CA_REQ_GO_IDLE)
+ sts |= CRB_STS_IDLE;
+
return sts;
}
@@ -206,6 +259,8 @@ static int crb_init(struct acpi_device *device, struct crb_priv *priv)
if (IS_ERR(chip))
return PTR_ERR(chip);
+ pm_runtime_set_active(&device->dev);
+ pm_runtime_enable(&device->dev);
dev_set_drvdata(&chip->dev, priv);
chip->acpi_dev_handle = device->handle;
chip->flags = TPM_CHIP_FLAG_TPM2;
@@ -348,6 +403,8 @@ static int crb_acpi_add(struct acpi_device *device)
!strcmp(acpi_device_hid(device), "MSFT0101"))
priv->flags |= CRB_FL_CRB_START;
+ init_waitqueue_head(&priv->idle_queue);
+
if (sm == ACPI_TPM2_START_METHOD ||
sm == ACPI_TPM2_COMMAND_BUFFER_WITH_START_METHOD)
priv->flags |= CRB_FL_ACPI_START;
@@ -366,6 +423,7 @@ static int crb_acpi_remove(struct acpi_device *device)
tpm_chip_unregister(chip);
+ pm_runtime_disable(dev);
return 0;
}
--
2.7.4
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