tpm: move the PPI attributes to character device directory.

Moved PPI attributes to the character device directory. This aligns with
the sysfs guidelines and makes them race free because they are created
atomically with the character device as part of device_register().The
character device and the sysfs attributes appear at the same time to the
user space.

As part of this change we enable PPI attributes also for TPM 2.0
devices. In order to retain backwards compatibility with TPM 1.x
devices, a symlink is created to the platform device directory.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: Jason Gunthorpe <jason.gunthorpe@obsidianresearch.com>
Tested-by: Mimi Zohar <zohar@linux.vnet.ibm.com> (on TPM 1.2)
Tested-by: Chris J Arges <chris.j.arges@canonical.com>
Tested-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>

1 files changed, 11 insertions, 23 deletions

diff --git a/drivers/char/tpm/tpm_ppi.c b/drivers/char/tpm/tpm_ppi.c
index 6ca9b5d78144..692a2c6ae036 100644
--- a/drivers/char/tpm/tpm_ppi.c
+++ b/drivers/char/tpm/tpm_ppi.c
@@ -53,7 +53,7 @@ tpm_eval_dsm(acpi_handle ppi_handle, int func, acpi_object_type type,
 static ssize_t tpm_show_ppi_version(struct device *dev,
 				    struct device_attribute *attr, char *buf)
 {
-	struct tpm_chip *chip = dev_get_drvdata(dev);
+	struct tpm_chip *chip = to_tpm_chip(dev);
 
 	return scnprintf(buf, PAGE_SIZE, "%s\n", chip->ppi_version);
 }
@@ -63,7 +63,7 @@ static ssize_t tpm_show_ppi_request(struct device *dev,
 {
 	ssize_t size = -EINVAL;
 	union acpi_object *obj;
-	struct tpm_chip *chip = dev_get_drvdata(dev);
+	struct tpm_chip *chip = to_tpm_chip(dev);
 
 	obj = tpm_eval_dsm(chip->acpi_dev_handle, TPM_PPI_FN_GETREQ,
 			   ACPI_TYPE_PACKAGE, NULL);
@@ -100,7 +100,7 @@ static ssize_t tpm_store_ppi_request(struct device *dev,
 	int func = TPM_PPI_FN_SUBREQ;
 	union acpi_object *obj, tmp;
 	union acpi_object argv4 = ACPI_INIT_DSM_ARGV4(1, &tmp);
-	struct tpm_chip *chip = dev_get_drvdata(dev);
+	struct tpm_chip *chip = to_tpm_chip(dev);
 
 	/*
 	 * the function to submit TPM operation request to pre-os environment
@@ -156,7 +156,7 @@ static ssize_t tpm_show_ppi_transition_action(struct device *dev,
 		.buffer.length = 0,
 		.buffer.pointer = NULL
 	};
-	struct tpm_chip *chip = dev_get_drvdata(dev);
+	struct tpm_chip *chip = to_tpm_chip(dev);
 
 	static char *info[] = {
 		"None",
@@ -197,7 +197,7 @@ static ssize_t tpm_show_ppi_response(struct device *dev,
 	acpi_status status = -EINVAL;
 	union acpi_object *obj, *ret_obj;
 	u64 req, res;
-	struct tpm_chip *chip = dev_get_drvdata(dev);
+	struct tpm_chip *chip = to_tpm_chip(dev);
 
 	obj = tpm_eval_dsm(chip->acpi_dev_handle, TPM_PPI_FN_GETRSP,
 			   ACPI_TYPE_PACKAGE, NULL);
@@ -296,7 +296,7 @@ static ssize_t tpm_show_ppi_tcg_operations(struct device *dev,
 					   struct device_attribute *attr,
 					   char *buf)
 {
-	struct tpm_chip *chip = dev_get_drvdata(dev);
+	struct tpm_chip *chip = to_tpm_chip(dev);
 
 	return show_ppi_operations(chip->acpi_dev_handle, buf, 0,
 				   PPI_TPM_REQ_MAX);
@@ -306,7 +306,7 @@ static ssize_t tpm_show_ppi_vs_operations(struct device *dev,
 					  struct device_attribute *attr,
 					  char *buf)
 {
-	struct tpm_chip *chip = dev_get_drvdata(dev);
+	struct tpm_chip *chip = to_tpm_chip(dev);
 
 	return show_ppi_operations(chip->acpi_dev_handle, buf, PPI_VS_REQ_START,
 				   PPI_VS_REQ_END);
@@ -334,17 +334,16 @@ static struct attribute_group ppi_attr_grp = {
 	.attrs = ppi_attrs
 };
 
-int tpm_add_ppi(struct tpm_chip *chip)
+void tpm_add_ppi(struct tpm_chip *chip)
 {
 	union acpi_object *obj;
-	int rc;
 
 	if (!chip->acpi_dev_handle)
-		return 0;
+		return;
 
 	if (!acpi_check_dsm(chip->acpi_dev_handle, tpm_ppi_uuid,
 			    TPM_PPI_REVISION_ID, 1 << TPM_PPI_FN_VERSION))
-		return 0;
+		return;
 
 	/* Cache PPI version string. */
 	obj = acpi_evaluate_dsm_typed(chip->acpi_dev_handle, tpm_ppi_uuid,
@@ -356,16 +355,5 @@ int tpm_add_ppi(struct tpm_chip *chip)
 		ACPI_FREE(obj);
 	}
 
-	rc = sysfs_create_group(&chip->pdev->kobj, &ppi_attr_grp);
-
-	if (!rc)
-		chip->flags |= TPM_CHIP_FLAG_PPI;
-
-	return rc;
-}
-
-void tpm_remove_ppi(struct tpm_chip *chip)
-{
-	if (chip->flags & TPM_CHIP_FLAG_PPI)
-		sysfs_remove_group(&chip->pdev->kobj, &ppi_attr_grp);
+	chip->groups[chip->groups_cnt++] = &ppi_attr_grp;
 }