crypto: crypto4xx - increase context and scatter ring buffer elements

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>

diff --git a/drivers/crypto/amcc/crypto4xx_core.h b/drivers/crypto/amcc/crypto4xx_core.h
index 97fb8288ab30fc2f2d7ad544dcbcf37f03111198..27e439c1f5bf5c5bf6f766933650449446ca7d3c 100644 (file)
--- a/drivers/crypto/amcc/crypto4xx_core.h
+++ b/drivers/crypto/amcc/crypto4xx_core.h
@@ -36,12 +36,12 @@
 #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