tpm: two-phase chip management functions

tpm_register_hardware() and tpm_remove_hardware() are called often
before initializing the device. The problem is that the device might
not be fully initialized when it comes visible to the user space.

This patch resolves the issue by diving initialization into two
parts:

- tpmm_chip_alloc() creates struct tpm_chip.

- tpm_chip_register() sets up the character device and sysfs
  attributes.

The framework takes care of freeing struct tpm_chip by using the devres
API. The broken release callback has been wiped. ACPI drivers do not
ever get this callback.

Regards to Jason Gunthorpe for carefully reviewing this part of the
code.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Reviewed-by: Jasob Gunthorpe <jason.gunthorpe@obsidianresearch.com>
Reviewed-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Tested-by: Scot Doyle <lkml14@scotdoyle.com>
Tested-by: Peter Huewe <peterhuewe@gmx.de>
[phuewe: update to upstream changes]
Signed-off-by: Peter Huewe <peterhuewe@gmx.de>

1 files changed, 7 insertions, 10 deletions

diff --git a/drivers/char/tpm/tpm_ibmvtpm.c b/drivers/char/tpm/tpm_ibmvtpm.c
index 96f5d448b84c..0840347e251c 100644
--- a/drivers/char/tpm/tpm_ibmvtpm.c
+++ b/drivers/char/tpm/tpm_ibmvtpm.c
@@ -270,8 +270,11 @@ static int ibmvtpm_crq_send_init(struct ibmvtpm_dev *ibmvtpm)
 static int tpm_ibmvtpm_remove(struct vio_dev *vdev)
 {
 	struct ibmvtpm_dev *ibmvtpm = ibmvtpm_get_data(&vdev->dev);
+	struct tpm_chip *chip = dev_get_drvdata(ibmvtpm->dev);
 	int rc = 0;
 
+	tpm_chip_unregister(chip);
+
 	free_irq(vdev->irq, ibmvtpm);
 
 	do {
@@ -290,8 +293,6 @@ static int tpm_ibmvtpm_remove(struct vio_dev *vdev)
 		kfree(ibmvtpm->rtce_buf);
 	}
 
-	tpm_remove_hardware(ibmvtpm->dev);
-
 	kfree(ibmvtpm);
 
 	return 0;
@@ -563,11 +564,9 @@ static int tpm_ibmvtpm_probe(struct vio_dev *vio_dev,
 	struct tpm_chip *chip;
 	int rc = -ENOMEM, rc1;
 
-	chip = tpm_register_hardware(dev, &tpm_ibmvtpm);
-	if (!chip) {
-		dev_err(dev, "tpm_register_hardware failed\n");
-		return -ENODEV;
-	}
+	chip = tpmm_chip_alloc(dev, &tpm_ibmvtpm);
+	if (IS_ERR(chip))
+		return PTR_ERR(chip);
 
 	ibmvtpm = kzalloc(sizeof(struct ibmvtpm_dev), GFP_KERNEL);
 	if (!ibmvtpm) {
@@ -637,7 +636,7 @@ static int tpm_ibmvtpm_probe(struct vio_dev *vio_dev,
 	if (rc)
 		goto init_irq_cleanup;
 
-	return rc;
+	return tpm_chip_register(chip);
 init_irq_cleanup:
 	do {
 		rc1 = plpar_hcall_norets(H_FREE_CRQ, vio_dev->unit_address);
@@ -652,8 +651,6 @@ cleanup:
 		kfree(ibmvtpm);
 	}
 
-	tpm_remove_hardware(dev);
-
 	return rc;
 }