tpm/tpm_crb: cache cmd_size register value.

Instead of expensive register access on retrieving cmd_size
on each send, save the value during initialization in the private
context. The value doesn't change.

Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>

diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
index e76a8ee2007416f7dd7c61b9d48fd7075d65bb74..18b5b83af36d61f7b15bb947b1193516bf8e269c 100644 (file)
--- a/drivers/char/tpm/tpm_crb.c
+++ b/drivers/char/tpm/tpm_crb.c
@@ -80,6 +80,7 @@ struct crb_priv {
        struct crb_control_area __iomem *cca;
        u8 __iomem *cmd;
        u8 __iomem *rsp;
+       u32 cmd_size;
 };
 
 static SIMPLE_DEV_PM_OPS(crb_pm, tpm_pm_suspend, tpm_pm_resume);
@@ -146,11 +147,9 @@ static int crb_send(struct tpm_chip *chip, u8 *buf, size_t len)
         */
        iowrite32(0, &priv->cca->cancel);
 
-       if (len > ioread32(&priv->cca->cmd_size)) {
-               dev_err(&chip->dev,
-                       "invalid command count value %x %zx\n",
-                       (unsigned int) len,
-                       (size_t) ioread32(&priv->cca->cmd_size));
+       if (len > priv->cmd_size) {
+               dev_err(&chip->dev, "invalid command count value %zd %d\n",
+                       len, priv->cmd_size);
                return -E2BIG;
        }
 
@@ -301,6 +300,7 @@ static int crb_map_io(struct acpi_device *device, struct crb_priv *priv,
                dev_err(dev, FW_BUG "overlapping command and response buffer sizes are not identical");
                return -EINVAL;
        }
+       priv->cmd_size = cmd_size;
 
        priv->rsp = priv->cmd;
        return 0;