crypto: caam - set RDB bit in security configuration register

This change is required for post SEC-5.0 devices which have RNG4.
Setting RDB in security configuration register allows CAAM to use the
"Random Data Buffer" to be filled by a single request. The Random Data
Buffer is large enough for ten packets to get their IVs from a single
request. If the Random Data Buffer is not enabled, then each IV causes a
separate request, and RNG4 hardware cannot keep up resulting in lower
IPSEC throughput if random IVs are used.

Signed-off-by: Vakul Garg <vakul@freescale.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

2 files changed, 6 insertions, 1 deletions

diff --git a/drivers/crypto/caam/ctrl.c b/drivers/crypto/caam/ctrl.c
index 1c56f63524f2..19faea2c31d1 100644
--- a/drivers/crypto/caam/ctrl.c
+++ b/drivers/crypto/caam/ctrl.c
@@ -304,6 +304,9 @@ static int caam_probe(struct platform_device *pdev)
                         caam_remove(pdev);
                         return ret;
                 }
+
+                /* Enable RDB bit so that RNG works faster */
+                setbits32(&topregs->ctrl.scfgr, SCFGR_RDBENABLE);
         }
 
         /* NOTE: RTIC detection ought to go here, around Si time */
diff --git a/drivers/crypto/caam/regs.h b/drivers/crypto/caam/regs.h
index 3223fc6d647c..cd6fedad9935 100644
--- a/drivers/crypto/caam/regs.h
+++ b/drivers/crypto/caam/regs.h
@@ -252,7 +252,8 @@ struct caam_ctrl {
         /* Read/Writable                                                */
         u32 rsvd1;
         u32 mcr;                /* MCFG      Master Config Register  */
-        u32 rsvd2[2];
+        u32 rsvd2;
+        u32 scfgr;              /* SCFGR, Security Config Register */
 
         /* Bus Access Configuration Section                     010-11f */
         /* Read/Writable                                                */
@@ -299,6 +300,7 @@ struct caam_ctrl {
 #define MCFGR_WDFAIL            0x20000000 /* DECO watchdog force-fail */
 #define MCFGR_DMA_RESET         0x10000000
 #define MCFGR_LONG_PTR          0x00010000 /* Use >32-bit desc addressing */
+#define SCFGR_RDBENABLE         0x00000400
 
 /* AXI read cache control */
 #define MCFGR_ARCACHE_SHIFT     12