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authorBharat Bhushan <Bharat.Bhushan@freescale.com>2012-07-11 07:06:10 +0400
committerHerbert Xu <herbert@gondor.apana.org.au>2012-07-11 07:06:10 +0400
commit1af8ea862c9a9a6d5dc100850036cc7a641bb242 (patch)
tree6c17ecaad399d4a5ce1a12f17020a72e17259dc1 /drivers/crypto
parent26c8aaebc188b539a0a9077350009a059464097d (diff)
downloadlinux-1af8ea862c9a9a6d5dc100850036cc7a641bb242.tar.xz
crypto: caam - Using alloc_coherent for caam job rings
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>
Diffstat (limited to 'drivers/crypto')
-rw-r--r--drivers/crypto/caam/jr.c45
1 files changed, 9 insertions, 36 deletions
diff --git a/drivers/crypto/caam/jr.c b/drivers/crypto/caam/jr.c
index 7074a1a29e8b..53c8c51d5881 100644
--- a/drivers/crypto/caam/jr.c
+++ b/drivers/crypto/caam/jr.c
@@ -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;