linux-stable/drivers/crypto/caam/sg_sw_sec4.h
Horia Geantă 059d73eea6 crypto: caam - use len instead of nents for bulding HW S/G table
Currently, conversion of SW S/G table into HW S/G layout relies on
nents returned by sg_nents_for_len(sg, len).
However this leaves the possibility of HW S/G referencing more data
then needed: since buffer length in HW S/G entries is filled using
sg_dma_len(sg), the last entry in HW S/G table might have a length
that is bigger than needed for the crypto request.

This way of S/G table conversion is fine, unless after converting a table
more entries have to be appended to the HW S/G table.
In this case, crypto engine would access data from the S/G entry having
the incorrect length, instead of advancing in the S/G table.
This situation doesn't exist, but the upcoming implementation of
IV update for skcipher algorithms needs to add a S/G entry after
req->dst S/G (corresponding to output IV).

Signed-off-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2019-06-20 14:18:33 +08:00

85 lines
2 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
/*
* CAAM/SEC 4.x functions for using scatterlists in caam driver
*
* Copyright 2008-2011 Freescale Semiconductor, Inc.
*
*/
#ifndef _SG_SW_SEC4_H_
#define _SG_SW_SEC4_H_
#include "ctrl.h"
#include "regs.h"
#include "sg_sw_qm2.h"
#include <soc/fsl/dpaa2-fd.h>
struct sec4_sg_entry {
u64 ptr;
u32 len;
u32 bpid_offset;
};
/*
* convert single dma address to h/w link table format
*/
static inline void dma_to_sec4_sg_one(struct sec4_sg_entry *sec4_sg_ptr,
dma_addr_t dma, u32 len, u16 offset)
{
if (caam_dpaa2) {
dma_to_qm_sg_one((struct dpaa2_sg_entry *)sec4_sg_ptr, dma, len,
offset);
} else {
sec4_sg_ptr->ptr = cpu_to_caam_dma64(dma);
sec4_sg_ptr->len = cpu_to_caam32(len);
sec4_sg_ptr->bpid_offset = cpu_to_caam32(offset &
SEC4_SG_OFFSET_MASK);
}
print_hex_dump_debug("sec4_sg_ptr@: ", DUMP_PREFIX_ADDRESS, 16, 4,
sec4_sg_ptr, sizeof(struct sec4_sg_entry), 1);
}
/*
* convert scatterlist to h/w link table format
* but does not have final bit; instead, returns last entry
*/
static inline struct sec4_sg_entry *
sg_to_sec4_sg(struct scatterlist *sg, int len,
struct sec4_sg_entry *sec4_sg_ptr, u16 offset)
{
int ent_len;
while (len) {
ent_len = min_t(int, sg_dma_len(sg), len);
dma_to_sec4_sg_one(sec4_sg_ptr, sg_dma_address(sg), ent_len,
offset);
sec4_sg_ptr++;
sg = sg_next(sg);
len -= ent_len;
}
return sec4_sg_ptr - 1;
}
static inline void sg_to_sec4_set_last(struct sec4_sg_entry *sec4_sg_ptr)
{
if (caam_dpaa2)
dpaa2_sg_set_final((struct dpaa2_sg_entry *)sec4_sg_ptr, true);
else
sec4_sg_ptr->len |= cpu_to_caam32(SEC4_SG_LEN_FIN);
}
/*
* convert scatterlist to h/w link table format
* scatterlist must have been previously dma mapped
*/
static inline void sg_to_sec4_sg_last(struct scatterlist *sg, int len,
struct sec4_sg_entry *sec4_sg_ptr,
u16 offset)
{
sec4_sg_ptr = sg_to_sec4_sg(sg, len, sec4_sg_ptr, offset);
sg_to_sec4_set_last(sec4_sg_ptr);
}
#endif /* _SG_SW_SEC4_H_ */