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From:   Gilad Ben-Yossef <gilad@benyossef.com>
To:     Herbert Xu <herbert@gondor.apana.org.au>,
        "David S. Miller" <davem@davemloft.net>
Cc:     Ofir Drang <ofir.drang@arm.com>, stable@vger.kernel.org,
        linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH 2/4] crypto: ccree: account for TEE not ready to report
Date:   Tue,  2 Jul 2019 14:39:19 +0300
Message-Id: <20190702113922.24911-3-gilad@benyossef.com>
In-Reply-To: <20190702113922.24911-1-gilad@benyossef.com>
References: <20190702113922.24911-1-gilad@benyossef.com>
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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: ab8ec9658f5a ("crypto: ccree - add FIPS support")
CC: stable@vger.kernel.org # v4.17+
---
 drivers/crypto/ccree/cc_fips.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/drivers/crypto/ccree/cc_fips.c b/drivers/crypto/ccree/cc_fips.c
index 5ad3ffb7acaa..040e09c0e1af 100644
--- a/drivers/crypto/ccree/cc_fips.c
+++ b/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;
 }
 
 /*
-- 
2.21.0