[PATCH v2] tpm: Fix the driver cleanup code

[Azhar Shaikh]

Commit 3c1701339284353c41 ("tpm: Keep CLKRUN enabled throughout
the duration of transmit_cmd()") added code which accessed
chip->ops, even after it was set to NULL in tpm_del_char_device(),
called from tpm_chip_unregister() in error / driver exit paths.
So fix this code.

Fixes: 3c1701339284353c41 ("tpm: Keep CLKRUN enabled throughout
the duration of transmit_cmd()")

Suggested-by: Javier Martinez Canillas <javi...@redhat.com>
Suggested-by: Jason Gunthorpe <j...@ziepe.ca>
Signed-off-by: Azhar Shaikh <azhar.sha...@intel.com>
---
Changes in v2:
- Remove TPM_CHIP_FLAG_DO_NOT_CLEAR_OPS flag, instead call
  tpm_tis_clkrun_enable() directly in tpm_tis_remove()
- Add comment to tpm_tis_clkrun_enable()

 drivers/char/tpm/tpm_tis.c      |  6 ------
 drivers/char/tpm/tpm_tis_core.c | 29 +++++++++++++++++------------
 2 files changed, 17 insertions(+), 18 deletions(-)

diff --git a/drivers/char/tpm/tpm_tis.c b/drivers/char/tpm/tpm_tis.c
index d29add49b033..c847fc69a2fc 100644
--- a/drivers/char/tpm/tpm_tis.c
+++ b/drivers/char/tpm/tpm_tis.c
@@ -275,9 +275,6 @@ static void tpm_tis_pnp_remove(struct pnp_dev *dev)
 
        tpm_chip_unregister(chip);
        tpm_tis_remove(chip);
-       if (is_bsw())
-               iounmap(priv->ilb_base_addr);
-
 }
 
 static struct pnp_driver tis_pnp_driver = {
@@ -329,9 +326,6 @@ static int tpm_tis_plat_remove(struct platform_device *pdev)
        tpm_chip_unregister(chip);
        tpm_tis_remove(chip);
 
-       if (is_bsw())
-               iounmap(priv->ilb_base_addr);
-
        return 0;
 }
 
diff --git a/drivers/char/tpm/tpm_tis_core.c b/drivers/char/tpm/tpm_tis_core.c
index c2227983ed88..519e4a78c8f8 100644
--- a/drivers/char/tpm/tpm_tis_core.c
+++ b/drivers/char/tpm/tpm_tis_core.c
@@ -37,6 +37,8 @@
  */
 #define TPM_POLL_SLEEP 1  /* msec */
 
+static void tpm_tis_clkrun_enable(struct tpm_chip *chip, bool value);
+
 static bool wait_for_tpm_stat_cond(struct tpm_chip *chip, u8 mask,
                                        bool check_cancel, bool *canceled)
 {
@@ -716,8 +718,7 @@ void tpm_tis_remove(struct tpm_chip *chip)
        u32 interrupt;
        int rc;
 
-       if (chip->ops->clk_enable != NULL)
-               chip->ops->clk_enable(chip, true);
+       tpm_tis_clkrun_enable(chip, true);
 
        rc = tpm_tis_read32(priv, reg, &interrupt);
        if (rc < 0)
@@ -725,8 +726,10 @@ void tpm_tis_remove(struct tpm_chip *chip)
 
        tpm_tis_write32(priv, reg, ~TPM_GLOBAL_INT_ENABLE & interrupt);
 
-       if (chip->ops->clk_enable != NULL)
-               chip->ops->clk_enable(chip, false);
+       tpm_tis_clkrun_enable(chip, false);
+
+       if (priv->ilb_base_addr)
+               iounmap(priv->ilb_base_addr);
 }
 EXPORT_SYMBOL_GPL(tpm_tis_remove);
 
@@ -736,6 +739,9 @@ void tpm_tis_remove(struct tpm_chip *chip)
  * @chip:      TPM chip to use
  * @value:     1 - Disable CLKRUN protocol, so that clocks are free running
  *             0 - Enable CLKRUN protocol
+ *
+ * Call this function directly in tpm_tis_remove() in error or driver removal
+ * path, since the chip->ops is set to NULL in tpm_chip_unregister().
  */
 static void tpm_tis_clkrun_enable(struct tpm_chip *chip, bool value)
 {
@@ -922,21 +928,20 @@ int tpm_tis_core_init(struct device *dev, struct 
tpm_tis_data *priv, int irq,
        }
 
        rc = tpm_chip_register(chip);
-       if (rc && is_bsw())
-               iounmap(priv->ilb_base_addr);
+       if (rc)
+               goto out_err;
 
        if (chip->ops->clk_enable != NULL)
                chip->ops->clk_enable(chip, false);
 
-       return rc;
-out_err:
-       tpm_tis_remove(chip);
-       if (is_bsw())
-               iounmap(priv->ilb_base_addr);
+       return 0;
 
-       if (chip->ops->clk_enable != NULL)
+out_err:
+       if ((chip->ops != NULL) && (chip->ops->clk_enable != NULL))
                chip->ops->clk_enable(chip, false);
 
+       tpm_tis_remove(chip);
+
        return rc;
 }
 EXPORT_SYMBOL_GPL(tpm_tis_core_init);
-- 
1.9.1