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crypto: caam - Using alloc_coherent for caam job rings

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The caam job rings (input/output job ring) are allocated using
dma_map_single(). These job rings can be visualized as the ring
buffers in which the jobs are en-queued/de-queued. The s/w enqueues
the jobs in input job ring which h/w dequeues and after processing
it copies the jobs in output job ring. Software then de-queues the
job from output ring. Using dma_map/unmap_single() is not preferred
way to allocate memory for this type of requirements because this
adds un-necessary complexity.

Example, if bounce buffer (SWIOTLB) will get used then to make any
change visible in this memory to other processing unit requires
dmap_unmap_single() or dma_sync_single_for_cpu/device(). The
dma_unmap_single() can not be used as this will free the bounce
buffer, this will require changing the job rings on running system
and I seriously doubt that it will be not possible or very complex
to implement. Also using dma_sync_single_for_cpu/device() will also
add unnecessary complexity.

The simple and preferred way is using dma_alloc_coherent() for these
type of memory requirements.

This resolves the Linux boot crash issue when "swiotlb=force" is set
in bootargs on systems which have memory more than 4G.

Signed-off-by: Bharat Bhushan <bharat.bhushan@freescale.com>
Acked-by: Kim Phillips <kim.phillips@freescale.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
This commit is contained in:
Bharat Bhushan 2012-07-11 11:06:10 +08:00 committed by Herbert Xu
parent 26c8aaebc1
commit 1af8ea862c
1 changed files with 9 additions and 36 deletions
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45
drivers/crypto/caam/jr.c
View file

@ -339,10 +339,11 @@ static int caam_jr_init(struct device *dev)
if (error)
return error;
jrp->inpring = kzalloc(sizeof(dma_addr_t) * JOBR_DEPTH,
GFP_KERNEL | GFP_DMA);
jrp->outring = kzalloc(sizeof(struct jr_outentry) *
JOBR_DEPTH, GFP_KERNEL | GFP_DMA);
jrp->inpring = dma_alloc_coherent(dev, sizeof(dma_addr_t) * JOBR_DEPTH,
&inpbusaddr, GFP_KERNEL);
jrp->outring = dma_alloc_coherent(dev, sizeof(struct jr_outentry) *
JOBR_DEPTH, &outbusaddr, GFP_KERNEL);
jrp->entinfo = kzalloc(sizeof(struct caam_jrentry_info) * JOBR_DEPTH,
GFP_KERNEL);
@ -358,31 +359,6 @@ static int caam_jr_init(struct device *dev)
jrp->entinfo[i].desc_addr_dma = !0;
/* Setup rings */
inpbusaddr = dma_map_single(dev, jrp->inpring,
sizeof(dma_addr_t) * JOBR_DEPTH,
DMA_BIDIRECTIONAL);
if (dma_mapping_error(dev, inpbusaddr)) {
dev_err(dev, "caam_jr_init(): can't map input ring\n");
kfree(jrp->inpring);
kfree(jrp->outring);
kfree(jrp->entinfo);
return -EIO;
}
outbusaddr = dma_map_single(dev, jrp->outring,
sizeof(struct jr_outentry) * JOBR_DEPTH,
DMA_BIDIRECTIONAL);
if (dma_mapping_error(dev, outbusaddr)) {
dev_err(dev, "caam_jr_init(): can't map output ring\n");
dma_unmap_single(dev, inpbusaddr,
sizeof(dma_addr_t) * JOBR_DEPTH,
DMA_BIDIRECTIONAL);
kfree(jrp->inpring);
kfree(jrp->outring);
kfree(jrp->entinfo);
return -EIO;
}
jrp->inp_ring_write_index = 0;
jrp->out_ring_read_index = 0;
jrp->head = 0;
@ -426,13 +402,10 @@ int caam_jr_shutdown(struct device *dev)
/* Free rings */
inpbusaddr = rd_reg64(&jrp->rregs->inpring_base);
outbusaddr = rd_reg64(&jrp->rregs->outring_base);
dma_unmap_single(dev, outbusaddr,
sizeof(struct jr_outentry) * JOBR_DEPTH,
DMA_BIDIRECTIONAL);
dma_unmap_single(dev, inpbusaddr, sizeof(dma_addr_t) * JOBR_DEPTH,
DMA_BIDIRECTIONAL);
kfree(jrp->outring);
kfree(jrp->inpring);
dma_free_coherent(dev, sizeof(dma_addr_t) * JOBR_DEPTH,
jrp->inpring, inpbusaddr);
dma_free_coherent(dev, sizeof(struct jr_outentry) * JOBR_DEPTH,
jrp->outring, outbusaddr);
kfree(jrp->entinfo);
return ret;