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, 1 insertions, 147 deletions

diff --git a/drivers/char/tpm/tpm-interface.c b/drivers/char/tpm/tpm-interface.c
index c17aa45024aa..4dbed1e45abd 100644
--- a/drivers/char/tpm/tpm-interface.c
+++ b/drivers/char/tpm/tpm-interface.c
@@ -1,5 +1,6 @@
 /*
  * Copyright (C) 2004 IBM Corporation
+ * Copyright (C) 2014 Intel Corporation
  *
  * Authors:
  * Leendert van Doorn <leendert@watson.ibm.com>
@@ -47,10 +48,6 @@ module_param_named(suspend_pcr, tpm_suspend_pcr, uint, 0644);
 MODULE_PARM_DESC(suspend_pcr,
 		 "PCR to use for dummy writes to faciltate flush on suspend.");
 
-static LIST_HEAD(tpm_chip_list);
-static DEFINE_SPINLOCK(driver_lock);
-static DECLARE_BITMAP(dev_mask, TPM_NUM_DEVICES);
-
 /*
  * Array with one entry per ordinal defining the maximum amount
  * of time the chip could take to return the result.  The ordinal
@@ -639,27 +636,6 @@ static int tpm_continue_selftest(struct tpm_chip *chip)
 	return rc;
 }
 
-/*
- * tpm_chip_find_get - return tpm_chip for given chip number
- */
-static struct tpm_chip *tpm_chip_find_get(int chip_num)
-{
-	struct tpm_chip *pos, *chip = NULL;
-
-	rcu_read_lock();
-	list_for_each_entry_rcu(pos, &tpm_chip_list, list) {
-		if (chip_num != TPM_ANY_NUM && chip_num != pos->dev_num)
-			continue;
-
-		if (try_module_get(pos->dev->driver->owner)) {
-			chip = pos;
-			break;
-		}
-	}
-	rcu_read_unlock();
-	return chip;
-}
-
 #define TPM_ORDINAL_PCRREAD cpu_to_be32(21)
 #define READ_PCR_RESULT_SIZE 30
 static struct tpm_input_header pcrread_header = {
@@ -887,30 +863,6 @@ again:
 }
 EXPORT_SYMBOL_GPL(wait_for_tpm_stat);
 
-void tpm_remove_hardware(struct device *dev)
-{
-	struct tpm_chip *chip = dev_get_drvdata(dev);
-
-	if (chip == NULL) {
-		dev_err(dev, "No device data found\n");
-		return;
-	}
-
-	spin_lock(&driver_lock);
-	list_del_rcu(&chip->list);
-	spin_unlock(&driver_lock);
-	synchronize_rcu();
-
-	tpm_dev_del_device(chip);
-	tpm_sysfs_del_device(chip);
-	tpm_remove_ppi(&dev->kobj);
-	tpm_bios_log_teardown(chip->bios_dir);
-
-	/* write it this way to be explicit (chip->dev == dev) */
-	put_device(chip->dev);
-}
-EXPORT_SYMBOL_GPL(tpm_remove_hardware);
-
 #define TPM_ORD_SAVESTATE cpu_to_be32(152)
 #define SAVESTATE_RESULT_SIZE 10
 
@@ -1044,104 +996,6 @@ int tpm_get_random(u32 chip_num, u8 *out, size_t max)
 }
 EXPORT_SYMBOL_GPL(tpm_get_random);
 
-/* In case vendor provided release function, call it too.*/
-
-void tpm_dev_vendor_release(struct tpm_chip *chip)
-{
-	if (!chip)
-		return;
-
-	clear_bit(chip->dev_num, dev_mask);
-}
-EXPORT_SYMBOL_GPL(tpm_dev_vendor_release);
-
-
-/*
- * Once all references to platform device are down to 0,
- * release all allocated structures.
- */
-static void tpm_dev_release(struct device *dev)
-{
-	struct tpm_chip *chip = dev_get_drvdata(dev);
-
-	if (!chip)
-		return;
-
-	tpm_dev_vendor_release(chip);
-
-	chip->release(dev);
-	kfree(chip);
-}
-
-/*
- * Called from tpm_<specific>.c probe function only for devices
- * the driver has determined it should claim.  Prior to calling
- * this function the specific probe function has called pci_enable_device
- * upon errant exit from this function specific probe function should call
- * pci_disable_device
- */
-struct tpm_chip *tpm_register_hardware(struct device *dev,
-				       const struct tpm_class_ops *ops)
-{
-	struct tpm_chip *chip;
-
-	/* Driver specific per-device data */
-	chip = kzalloc(sizeof(*chip), GFP_KERNEL);
-
-	if (chip == NULL)
-		return NULL;
-
-	mutex_init(&chip->tpm_mutex);
-	INIT_LIST_HEAD(&chip->list);
-
-	chip->ops = ops;
-	chip->dev_num = find_first_zero_bit(dev_mask, TPM_NUM_DEVICES);
-
-	if (chip->dev_num >= TPM_NUM_DEVICES) {
-		dev_err(dev, "No available tpm device numbers\n");
-		goto out_free;
-	}
-
-	set_bit(chip->dev_num, dev_mask);
-
-	scnprintf(chip->devname, sizeof(chip->devname), "%s%d", "tpm",
-		  chip->dev_num);
-
-	chip->dev = get_device(dev);
-	chip->release = dev->release;
-	dev->release = tpm_dev_release;
-	dev_set_drvdata(dev, chip);
-
-	if (tpm_dev_add_device(chip))
-		goto put_device;
-
-	if (tpm_sysfs_add_device(chip))
-		goto del_misc;
-
-	if (tpm_add_ppi(&dev->kobj))
-		goto del_sysfs;
-
-	chip->bios_dir = tpm_bios_log_setup(chip->devname);
-
-	/* Make chip available */
-	spin_lock(&driver_lock);
-	list_add_tail_rcu(&chip->list, &tpm_chip_list);
-	spin_unlock(&driver_lock);
-
-	return chip;
-
-del_sysfs:
-	tpm_sysfs_del_device(chip);
-del_misc:
-	tpm_dev_del_device(chip);
-put_device:
-	put_device(chip->dev);
-out_free:
-	kfree(chip);
-	return NULL;
-}
-EXPORT_SYMBOL_GPL(tpm_register_hardware);
-
 MODULE_AUTHOR("Leendert van Doorn (leendert@watson.ibm.com)");
 MODULE_DESCRIPTION("TPM Driver");
 MODULE_VERSION("2.0");