crypto: ccree - account for TEE not ready to report

commit 76a95bd8 upstream.

When ccree driver runs it checks the state of the Trusted Execution
Environment CryptoCell driver before proceeding. We did not account
for cases where the TEE side is not ready or not available at all.
Fix it by only considering TEE error state after sync with the TEE
side driver.
Signed-off-by: Gilad Ben-Yossef <gilad@benyossef.com>
Fixes: ab8ec965 ("crypto: ccree - add FIPS support")
CC: stable@vger.kernel.org # v4.17+
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/crypto/ccree/cc_fips.c

@@ -21,7 +21,13 @@ static bool cc_get_tee_fips_status(struct cc_drvdata *drvdata)
 	u32 reg;
 
 	reg = cc_ioread(drvdata, CC_REG(GPR_HOST));
-	return (reg == (CC_FIPS_SYNC_TEE_STATUS | CC_FIPS_SYNC_MODULE_OK));
+	/* Did the TEE report status? */
+	if (reg & CC_FIPS_SYNC_TEE_STATUS)
+		/* Yes. Is it OK? */
+		return (reg & CC_FIPS_SYNC_MODULE_OK);
+
+	/* No. It's either not in use or will be reported later */
+	return true;
 }
 
 /*