[PATCH 3/3] tpm/tpm_crb: cache cmd_size register value.

[Tomas Winkler <tomas.winkler-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>]

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-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
 drivers/char/tpm/tpm_crb.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/char/tpm/tpm_crb.c b/drivers/char/tpm/tpm_crb.c
index cf9aab698dfe..f8c9d587029b 100644
--- a/drivers/char/tpm/tpm_crb.c
+++ b/drivers/char/tpm/tpm_crb.c
@@ -81,6 +81,7 @@ struct crb_priv {
 	struct crb_control_area __iomem *cca;
 	u8 __iomem *cmd;
 	u8 __iomem *rsp;
+	u32 cmd_size;
 };
 
 /**
@@ -217,11 +218,9 @@ static int crb_send(struct tpm_chip *chip, u8 *buf, size_t len)
 	struct crb_priv *priv = dev_get_drvdata(&chip->dev);
 	int rc = 0;
 
-	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;
 	}
 
@@ -374,6 +373,7 @@ static int crb_map_io(struct acpi_device *device, struct crb_priv *priv,
 		ret = PTR_ERR(priv->cmd);
 		goto out;
 	}
+	priv->cmd_size = cmd_size;
 
 	memcpy_fromio(&rsp_pa, &priv->cca->rsp_pa, 8);
 	rsp_pa = le64_to_cpu(rsp_pa);
-- 
2.7.4


------------------------------------------------------------------------------