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authorChristian Lamparter <chunkeey@gmail.com>2017-10-04 01:00:09 +0200
committerHerbert Xu <herbert@gondor.apana.org.au>2017-10-12 22:55:12 +0800
commit8ef8d195430ca3542d0434cf25e5115484b9fa32 (patch)
tree4ea555d23564e16cd680e3dbe7a47753dba8a508 /drivers/crypto/amcc/crypto4xx_core.h
parent778f81d6cdb7d25360f082ac0384d5103f04eca5 (diff)
downloadlinux-8ef8d195430ca3542d0434cf25e5115484b9fa32.tar.gz
crypto: crypto4xx - add backlog queue support
Previously, If the crypto4xx driver used all available security contexts, it would simply refuse new requests with -EAGAIN. CRYPTO_TFM_REQ_MAY_BACKLOG was ignored. in case of dm-crypt.c's crypt_convert() function this was causing the following errors to manifest, if the system was pushed hard enough: | EXT4-fs warning (dm-1): ext4_end_bio:314: I/O error -5 writing to ino .. | EXT4-fs warning (dm-1): ext4_end_bio:314: I/O error -5 writing to ino .. | EXT4-fs warning (dm-1): ext4_end_bio:314: I/O error -5 writing to ino .. | JBD2: Detected IO errors while flushing file data on dm-1-8 | Aborting journal on device dm-1-8. | EXT4-fs error : ext4_journal_check_start:56: Detected aborted journal | EXT4-fs (dm-1): Remounting filesystem read-only | EXT4-fs : ext4_writepages: jbd2_start: 2048 pages, inode 498...; err -30 (This did cause corruptions due to failed writes) To fix this mess, the crypto4xx driver needs to notifiy the user to slow down. This can be achieved by returning -EBUSY on requests, once the crypto hardware was falling behind. Note: -EBUSY has two different meanings. Setting the flag CRYPTO_TFM_REQ_MAY_BACKLOG implies that the request was successfully queued, by the crypto driver. To achieve this requirement, the implementation introduces a threshold check and adds logic to the completion routines in much the same way as AMD's Cryptographic Coprocessor (CCP) driver do. Note2: Tests showed that dm-crypt starved ipsec traffic. Under load, ipsec links dropped to 0 Kbits/s. This is because dm-crypt's callback would instantly queue the next request. In order to not starve ipsec, the driver reserves a small portion of the available crypto contexts for this purpose. Signed-off-by: Christian Lamparter <chunkeey@gmail.com> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Diffstat (limited to 'drivers/crypto/amcc/crypto4xx_core.h')
-rw-r--r--drivers/crypto/amcc/crypto4xx_core.h3
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/crypto/amcc/crypto4xx_core.h b/drivers/crypto/amcc/crypto4xx_core.h
index 27e439c1f5bf..dbe29043e0c5 100644
--- a/drivers/crypto/amcc/crypto4xx_core.h
+++ b/drivers/crypto/amcc/crypto4xx_core.h
@@ -44,7 +44,8 @@
#define PPC4XX_LAST_SD (PPC4XX_NUM_SD - 1)
#define PPC4XX_SD_BUFFER_SIZE 2048
-#define PD_ENTRY_INUSE 1
+#define PD_ENTRY_BUSY BIT(1)
+#define PD_ENTRY_INUSE BIT(0)
#define PD_ENTRY_FREE 0
#define ERING_WAS_FULL 0xffffffff