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, 31 insertions, 49 deletions

diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c
index ccb140d60532..36f4fec11c2a 100644
--- a/drivers/char/tpm/tpm_tis.c
+++ b/drivers/char/tpm/tpm_tis.c
@@ -79,9 +79,6 @@ struct priv_data {
         bool irq_tested;
 };
 
-static LIST_HEAD(tis_chips);
-static DEFINE_MUTEX(tis_lock);
-
 #if defined(CONFIG_PNP) && defined(CONFIG_ACPI)
 static int is_itpm(struct pnp_dev *dev)
 {
@@ -572,6 +569,17 @@ static bool interrupts = true;
 module_param(interrupts, bool, 0444);
 MODULE_PARM_DESC(interrupts, "Enable interrupts");
 
+static void tpm_tis_remove(struct tpm_chip *chip)
+{
+        iowrite32(~TPM_GLOBAL_INT_ENABLE &
+                  ioread32(chip->vendor.iobase +
+                           TPM_INT_ENABLE(chip->vendor.
+                                          locality)),
+                  chip->vendor.iobase +
+                  TPM_INT_ENABLE(chip->vendor.locality));
+        release_locality(chip, chip->vendor.locality, 1);
+}
+
 static int tpm_tis_init(struct device *dev, resource_size_t start,
                         resource_size_t len, unsigned int irq)
 {
@@ -583,15 +591,16 @@ static int tpm_tis_init(struct device *dev, resource_size_t start,
         priv = devm_kzalloc(dev, sizeof(struct priv_data), GFP_KERNEL);
         if (priv == NULL)
                 return -ENOMEM;
-        if (!(chip = tpm_register_hardware(dev, &tpm_tis)))
-                return -ENODEV;
+
+        chip = tpmm_chip_alloc(dev, &tpm_tis);
+        if (IS_ERR(chip))
+                return PTR_ERR(chip);
+
         chip->vendor.priv = priv;
 
-        chip->vendor.iobase = ioremap(start, len);
-        if (!chip->vendor.iobase) {
-                rc = -EIO;
-                goto out_err;
-        }
+        chip->vendor.iobase = devm_ioremap(dev, start, len);
+        if (!chip->vendor.iobase)
+                return -EIO;
 
         /* Default timeouts */
         chip->vendor.timeout_a = msecs_to_jiffies(TIS_SHORT_TIMEOUT);
@@ -685,8 +694,8 @@ static int tpm_tis_init(struct device *dev, resource_size_t start,
                 for (i = irq_s; i <= irq_e && chip->vendor.irq == 0; i++) {
                         iowrite8(i, chip->vendor.iobase +
                                  TPM_INT_VECTOR(chip->vendor.locality));
-                        if (request_irq
-                            (i, tis_int_probe, IRQF_SHARED,
+                        if (devm_request_irq
+                            (dev, i, tis_int_probe, IRQF_SHARED,
                              chip->vendor.miscdev.name, chip) != 0) {
                                 dev_info(chip->dev,
                                          "Unable to request irq: %d for probe\n",
@@ -726,15 +735,14 @@ static int tpm_tis_init(struct device *dev, resource_size_t start,
                         iowrite32(intmask,
                                   chip->vendor.iobase +
                                   TPM_INT_ENABLE(chip->vendor.locality));
-                        free_irq(i, chip);
                 }
         }
         if (chip->vendor.irq) {
                 iowrite8(chip->vendor.irq,
                          chip->vendor.iobase +
                          TPM_INT_VECTOR(chip->vendor.locality));
-                if (request_irq
-                    (chip->vendor.irq, tis_int_handler, IRQF_SHARED,
+                if (devm_request_irq
+                    (dev, chip->vendor.irq, tis_int_handler, IRQF_SHARED,
                      chip->vendor.miscdev.name, chip) != 0) {
                         dev_info(chip->dev,
                                  "Unable to request irq: %d for use\n",
@@ -767,17 +775,9 @@ static int tpm_tis_init(struct device *dev, resource_size_t start,
                 goto out_err;
         }
 
-        INIT_LIST_HEAD(&chip->vendor.list);
-        mutex_lock(&tis_lock);
-        list_add(&chip->vendor.list, &tis_chips);
-        mutex_unlock(&tis_lock);
-
-
-        return 0;
+        return tpm_chip_register(chip);
 out_err:
-        if (chip->vendor.iobase)
-                iounmap(chip->vendor.iobase);
-        tpm_remove_hardware(chip->dev);
+        tpm_tis_remove(chip);
         return rc;
 }
 
@@ -859,13 +859,10 @@ MODULE_DEVICE_TABLE(pnp, tpm_pnp_tbl);
 static void tpm_tis_pnp_remove(struct pnp_dev *dev)
 {
         struct tpm_chip *chip = pnp_get_drvdata(dev);
-
-        tpm_dev_vendor_release(chip);
-
-        kfree(chip);
+        tpm_chip_unregister(chip);
+        tpm_tis_remove(chip);
 }
 
-
 static struct pnp_driver tis_pnp_driver = {
         .name = "tpm_tis",
         .id_table = tpm_pnp_tbl,
@@ -884,7 +881,7 @@ MODULE_PARM_DESC(hid, "Set additional specific HID for this driver to probe");
 
 static struct platform_driver tis_drv = {
         .driver = {
-                .name = "tpm_tis",
+                .name           = "tpm_tis",
                 .pm             = &tpm_tis_pm,
         },
 };
@@ -923,31 +920,16 @@ err_dev:
 
 static void __exit cleanup_tis(void)
 {
-        struct tpm_vendor_specific *i, *j;
         struct tpm_chip *chip;
-        mutex_lock(&tis_lock);
-        list_for_each_entry_safe(i, j, &tis_chips, list) {
-                chip = to_tpm_chip(i);
-                tpm_remove_hardware(chip->dev);
-                iowrite32(~TPM_GLOBAL_INT_ENABLE &
-                          ioread32(chip->vendor.iobase +
-                                   TPM_INT_ENABLE(chip->vendor.
-                                                  locality)),
-                          chip->vendor.iobase +
-                          TPM_INT_ENABLE(chip->vendor.locality));
-                release_locality(chip, chip->vendor.locality, 1);
-                if (chip->vendor.irq)
-                        free_irq(chip->vendor.irq, chip);
-                iounmap(i->iobase);
-                list_del(&i->list);
-        }
-        mutex_unlock(&tis_lock);
 #ifdef CONFIG_PNP
         if (!force) {
                 pnp_unregister_driver(&tis_pnp_driver);
                 return;
         }
 #endif
+        chip = dev_get_drvdata(&pdev->dev);
+        tpm_chip_unregister(chip);
+        tpm_tis_remove(chip);
         platform_device_unregister(pdev);
         platform_driver_unregister(&tis_drv);
 }