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authorMoritz Fischer <mdf@kernel.org>2017-02-27 09:19:01 -0600
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2017-03-17 15:10:48 +0900
commit7f33bbca14de25f24660441af5087440dd0d2fca (patch)
treef9c1759ea3a1f0644f28bcf259b9a4a7c3501339 /drivers/fpga/zynq-fpga.c
parent0f4f0c8ff1da9171bca0dc01ce5551e8b6d2f0f3 (diff)
downloadlinux-7f33bbca14de25f24660441af5087440dd0d2fca.tar.gz
fpga: zynq: Add support for encrypted bitstreams
Add support for encrypted bitstreams. For this to work the system
must be booted in secure mode.

In order for on-the-fly decryption to work, the PCAP clock rate
needs to be lowered via the PCAP_RATE_EN bit.

Signed-off-by: Moritz Fischer <mdf@kernel.org>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Signed-off-by: Alan Tull <atull@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/fpga/zynq-fpga.c')
-rw-r--r--drivers/fpga/zynq-fpga.c28
1 files changed, 25 insertions, 3 deletions
diff --git a/drivers/fpga/zynq-fpga.c b/drivers/fpga/zynq-fpga.c
index 34cb98139442..70b15b303471 100644
--- a/drivers/fpga/zynq-fpga.c
+++ b/drivers/fpga/zynq-fpga.c
@@ -72,6 +72,10 @@
 #define CTRL_PCAP_PR_MASK		BIT(27)
 /* Enable PCAP */
 #define CTRL_PCAP_MODE_MASK		BIT(26)
+/* Lower rate to allow decrypt on the fly */
+#define CTRL_PCAP_RATE_EN_MASK		BIT(25)
+/* System booted in secure mode */
+#define CTRL_SEC_EN_MASK		BIT(7)
 
 /* Miscellaneous Control Register bit definitions */
 /* Internal PCAP loopback */
@@ -266,6 +270,17 @@ static int zynq_fpga_ops_write_init(struct fpga_manager *mgr,
 	if (err)
 		return err;
 
+	/* check if bitstream is encrypted & and system's still secure */
+	if (info->flags & FPGA_MGR_ENCRYPTED_BITSTREAM) {
+		ctrl = zynq_fpga_read(priv, CTRL_OFFSET);
+		if (!(ctrl & CTRL_SEC_EN_MASK)) {
+			dev_err(&mgr->dev,
+				"System not secure, can't use crypted bitstreams\n");
+			err = -EINVAL;
+			goto out_err;
+		}
+	}
+
 	/* don't globally reset PL if we're doing partial reconfig */
 	if (!(info->flags & FPGA_MGR_PARTIAL_RECONFIG)) {
 		if (!zynq_fpga_has_sync(buf, count)) {
@@ -337,12 +352,19 @@ static int zynq_fpga_ops_write_init(struct fpga_manager *mgr,
 
 	/* set configuration register with following options:
 	 * - enable PCAP interface
-	 * - set throughput for maximum speed
+	 * - set throughput for maximum speed (if bistream not crypted)
 	 * - set CPU in user mode
 	 */
 	ctrl = zynq_fpga_read(priv, CTRL_OFFSET);
-	zynq_fpga_write(priv, CTRL_OFFSET,
-			(CTRL_PCAP_PR_MASK | CTRL_PCAP_MODE_MASK | ctrl));
+	if (info->flags & FPGA_MGR_ENCRYPTED_BITSTREAM)
+		zynq_fpga_write(priv, CTRL_OFFSET,
+				(CTRL_PCAP_PR_MASK | CTRL_PCAP_MODE_MASK
+				 | CTRL_PCAP_RATE_EN_MASK | ctrl));
+	else
+		zynq_fpga_write(priv, CTRL_OFFSET,
+				(CTRL_PCAP_PR_MASK | CTRL_PCAP_MODE_MASK
+				 | ctrl));
+
 
 	/* We expect that the command queue is empty right now. */
 	status = zynq_fpga_read(priv, STATUS_OFFSET);