diff mbox

[v2,2/3] fpga: zynq: Add support for encrypted bitstreams

Message ID 1487624123-13579-2-git-send-email-mdf@kernel.org (mailing list archive)
State Accepted, archived
Delegated to: Moritz Fischer
Headers show

Commit Message

Moritz Fischer Feb. 20, 2017, 8:55 p.m. UTC
From: Moritz Fischer <mdf@kernel.org>

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>
Cc: Alan Tull <atull@kernel.org>
Cc: Michal Simek <michal.simek@xilinx.com>
Cc: Sören Brinkmann <soren.brinkmann@xilinx.com>
Cc: linux-kernel@vger.kernel.org
Cc: linux-fpga@vger.kernel.org
---

Changes from v1:
- Renamed flag from FPGA_MGR_DECRYPT_BITSTREAM->FPGA_MGR_ENCRYPTED_BITSTREAM

---
 drivers/fpga/zynq-fpga.c | 28 +++++++++++++++++++++++++---
 1 file changed, 25 insertions(+), 3 deletions(-)

Comments

Michal Simek Feb. 21, 2017, 1:55 p.m. UTC | #1
On 20.2.2017 21:55, mdf@kernel.org wrote:
> From: Moritz Fischer <mdf@kernel.org>
> 
> 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>
> Cc: Alan Tull <atull@kernel.org>
> Cc: Michal Simek <michal.simek@xilinx.com>
> Cc: Sören Brinkmann <soren.brinkmann@xilinx.com>
> Cc: linux-kernel@vger.kernel.org
> Cc: linux-fpga@vger.kernel.org
> ---
> 
> Changes from v1:
> - Renamed flag from FPGA_MGR_DECRYPT_BITSTREAM->FPGA_MGR_ENCRYPTED_BITSTREAM
> 
> ---
>  drivers/fpga/zynq-fpga.c | 28 +++++++++++++++++++++++++---
>  1 file changed, 25 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/fpga/zynq-fpga.c b/drivers/fpga/zynq-fpga.c
> index 34cb981..70b15b3 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);
> 

Acked-by: Michal Simek <michal.simek@xilinx.com>

Thanks,
Michal

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Alan Tull Feb. 21, 2017, 4:36 p.m. UTC | #2
On Tue, Feb 21, 2017 at 7:55 AM, Michal Simek <michal.simek@xilinx.com> wrote:
> On 20.2.2017 21:55, mdf@kernel.org wrote:
>> From: Moritz Fischer <mdf@kernel.org>
>>
>> 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>
>> Cc: Alan Tull <atull@kernel.org>
>> Cc: Michal Simek <michal.simek@xilinx.com>
>> Cc: Sören Brinkmann <soren.brinkmann@xilinx.com>
>> Cc: linux-kernel@vger.kernel.org
>> Cc: linux-fpga@vger.kernel.org
>> ---
>>
>> Changes from v1:
>> - Renamed flag from FPGA_MGR_DECRYPT_BITSTREAM->FPGA_MGR_ENCRYPTED_BITSTREAM
>>
>> ---
>>  drivers/fpga/zynq-fpga.c | 28 +++++++++++++++++++++++++---
>>  1 file changed, 25 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/fpga/zynq-fpga.c b/drivers/fpga/zynq-fpga.c
>> index 34cb981..70b15b3 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);
>>
>
> Acked-by: Michal Simek <michal.simek@xilinx.com>

Acked-by: Alan Tull <atull@kernel.org>

>
> Thanks,
> Michal
>
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diff mbox

Patch

diff --git a/drivers/fpga/zynq-fpga.c b/drivers/fpga/zynq-fpga.c
index 34cb981..70b15b3 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);