[PATCH 4.14 105/159] crypto: crypto4xx - increase context and scatter ring buffer elements

Greg Kroah-Hartman
2017-12-22T09:03:17Z

From: Christian Lamparter <chunkeey@gmail.com>

[ Upstream commit 778f81d6cdb7d25360f082ac0384d5103f04eca5 ]

If crypto4xx is used in conjunction with dm-crypt, the available
ring buffer elements are not enough to handle the load properly.

On an aes-cbc-essiv:sha256 encrypted swap partition the read
performance is abyssal: (tested with hdparm -t)

/dev/mapper/swap_crypt:
Timing buffered disk reads: 14 MB in 3.68 seconds = 3.81 MB/sec

The patch increases both PPC4XX_NUM_SD and PPC4XX_NUM_PD to 256.
This improves the performance considerably:

/dev/mapper/swap_crypt:
Timing buffered disk reads: 104 MB in 3.03 seconds = 34.31 MB/sec

Furthermore, PPC4XX_LAST_SD, PPC4XX_LAST_GD and PPC4XX_LAST_PD
can be easily calculated from their respective PPC4XX_NUM_*
constant.

Signed-off-by: Christian Lamparter <chunkeey@gmail.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/crypto/amcc/crypto4xx_core.h | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

--- a/drivers/crypto/amcc/crypto4xx_core.h
+++ b/drivers/crypto/amcc/crypto4xx_core.h
@@ -34,12 +34,12 @@
#define PPC405EX_CE_RESET 0x00000008

#define CRYPTO4XX_CRYPTO_PRIORITY 300
-#define PPC4XX_LAST_PD 63
-#define PPC4XX_NUM_PD 64
-#define PPC4XX_LAST_GD 1023
+#define PPC4XX_NUM_PD 256
+#define PPC4XX_LAST_PD (PPC4XX_NUM_PD - 1)
#define PPC4XX_NUM_GD 1024
-#define PPC4XX_LAST_SD 63
-#define PPC4XX_NUM_SD 64
+#define PPC4XX_LAST_GD (PPC4XX_NUM_GD - 1)
+#define PPC4XX_NUM_SD 256
+#define PPC4XX_LAST_SD (PPC4XX_NUM_SD - 1)
#define PPC4XX_SD_BUFFER_SIZE 2048

#define PD_ENTRY_INUSE 1