On Thu, 9 Aug 2012 11:20:48 +0300, qiang.liu@xxxxxxxxxxxxx wrote:
> From: Qiang Liu <qiang.liu@xxxxxxxxxxxxx>
>
> Expose Talitos's XOR functionality to be used for RAID parity
> calculation via the Async_tx layer.
>
> Cc: Herbert Xu <herbert@xxxxxxxxxxxxxxxxxxx>
> Cc: David S. Miller <davem@xxxxxxxxxxxxx>
> Signed-off-by: Dipen Dudhat <Dipen.Dudhat@xxxxxxxxxxxxx>
> Signed-off-by: Maneesh Gupta <Maneesh.Gupta@xxxxxxxxxxxxx>
> Signed-off-by: Kim Phillips <kim.phillips@xxxxxxxxxxxxx>
> Signed-off-by: Vishnu Suresh <Vishnu@xxxxxxxxxxxxx>
> Signed-off-by: Qiang Liu <qiang.liu@xxxxxxxxxxxxx>
> ---
> drivers/crypto/Kconfig | 9 +
> drivers/crypto/talitos.c | 413 ++++++++++++++++++++++++++++++++++++++++++++++
> drivers/crypto/talitos.h | 53 ++++++
> 3 files changed, 475 insertions(+), 0 deletions(-)
> +static void talitos_xor_run_tx_complete_actions(struct talitos_xor_desc *desc,
> + struct talitos_xor_chan *xor_chan)
> +{
> + struct device *dev = xor_chan->dev;
> + dma_addr_t dest, addr;
> + unsigned int src_cnt = desc->unmap_src_cnt;
> + unsigned int len = desc->unmap_len;
> + enum dma_ctrl_flags flags = desc->async_tx.flags;
> + struct dma_async_tx_descriptor *tx = &desc->async_tx;
> +
> + /* unmap dma addresses */
> + dest = desc->hwdesc.ptr[6].ptr;
> + if (likely(!(flags & DMA_COMPL_SKIP_DEST_UNMAP)))
> + dma_unmap_page(dev, dest, len, DMA_BIDIRECTIONAL);
> +
> + desc->idx = 6 - src_cnt;
> + if (likely(!(flags & DMA_COMPL_SKIP_SRC_UNMAP))) {
> + while(desc->idx < 6) {
> + addr = desc->hwdesc.ptr[desc->idx++].ptr;
> + if (addr == dest)
> + continue;
> + dma_unmap_page(dev, addr, len, DMA_TO_DEVICE);
> + }
> + }
No need for braces around the while block.
> + /* run dependent operations */
> + dma_run_dependencies(tx);
> +}
> +static void talitos_release_xor(struct device *dev, struct talitos_desc *hwdesc,
> + void *context, int error)
> +{
> + struct talitos_xor_desc *desc = context;
> + struct talitos_xor_chan *xor_chan;
> + dma_async_tx_callback callback;
> + void *callback_param;
> +
> + if (unlikely(error))
> + dev_err(dev, "xor operation: talitos error %d\n", error);
> +
> + xor_chan = container_of(desc->async_tx.chan, struct talitos_xor_chan,
> + common);
> + spin_lock_bh(&xor_chan->desc_lock);
> + if (xor_chan->completed_cookie < desc->async_tx.cookie)
> + xor_chan->completed_cookie = desc->async_tx.cookie;
> +
> + callback = desc->async_tx.callback;
> + callback_param = desc->async_tx.callback_param;
> +
> + if (callback) {
> + spin_unlock_bh(&xor_chan->desc_lock);
> + callback(callback_param);
> + spin_lock_bh(&xor_chan->desc_lock);
> + }
Since callback_param is used only here, maybe:
if (callback) {
void *callback_param = desc->async_tx.callback_param;
spin_unlock_bh(&xor_chan->desc_lock);
callback(callback_param);
spin_lock_bh(&xor_chan->desc_lock);
}
> +
> + talitos_xor_run_tx_complete_actions(desc, xor_chan);
> +
> + list_del(&desc->node);
> + list_add_tail(&desc->node, &xor_chan->free_desc);
> + spin_unlock_bh(&xor_chan->desc_lock);
> + if (!list_empty(&xor_chan->pending_q))
> + talitos_process_pending(xor_chan);
> +}
> +static int talitos_alloc_chan_resources(struct dma_chan *chan)
> +{
> + struct talitos_xor_chan *xor_chan;
> + struct talitos_xor_desc *desc;
> + LIST_HEAD(tmp_list);
> + int i;
> +
> + xor_chan = container_of(chan, struct talitos_xor_chan, common);
> +
> + if (!list_empty(&xor_chan->free_desc))
> + return xor_chan->total_desc;
> +
> + for (i = 0; i < TALITOS_MAX_DESCRIPTOR_NR; i++) {
> + desc = talitos_xor_alloc_descriptor(xor_chan,
> + GFP_KERNEL | GFP_DMA);
talitos_xor_alloc_descriptor() is called here without holding
the xor_chan->desc_lock and it increments xor_chan->total_desc.
Isn't this an issue ?
> + if (!desc) {
> + dev_err(xor_chan->common.device->dev,
> + "Only %d initial descriptors\n", i);
> + break;
> + }
> + list_add_tail(&desc->node, &tmp_list);
> + }
> +
> + if (!i)
> + return -ENOMEM;
> +
> + /* At least one desc is allocated */
> + spin_lock_bh(&xor_chan->desc_lock);
> + list_splice_init(&tmp_list, &xor_chan->free_desc);
> + spin_unlock_bh(&xor_chan->desc_lock);
> +
> + return xor_chan->total_desc;
> +}
> +/**
> + * talitos_register_dma_async - Initialize the Freescale XOR ADMA device
> + * It is registered as a DMA device with the capability to perform
> + * XOR operation with the Async_tx layer.
> + * The various queues and channel resources are also allocated.
> + */
> +static int talitos_register_async_tx(struct device *dev, int max_xor_srcs)
> +{
> + struct talitos_private *priv = dev_get_drvdata(dev);
> + struct dma_device *dma_dev = &priv->dma_dev_common;
> + struct talitos_xor_chan *xor_chan;
> + int err;
> +
> + xor_chan = kzalloc(sizeof(struct talitos_xor_chan), GFP_KERNEL);
> + if (!xor_chan) {
> + dev_err(dev, "unable to allocate xor channel\n");
> + return -ENOMEM;
> + }
> +
> + dma_dev->dev = dev;
> + dma_dev->device_alloc_chan_resources = talitos_alloc_chan_resources;
> + dma_dev->device_free_chan_resources = talitos_free_chan_resources;
> + dma_dev->device_prep_dma_xor = talitos_prep_dma_xor;
> + dma_dev->max_xor = max_xor_srcs;
> + dma_dev->device_tx_status = talitos_is_tx_complete;
> + dma_dev->device_issue_pending = talitos_issue_pending;
> + INIT_LIST_HEAD(&dma_dev->channels);
> + dma_cap_set(DMA_XOR, dma_dev->cap_mask);
> +
> + xor_chan->dev = dev;
> + xor_chan->common.device = dma_dev;
> + xor_chan->total_desc = 0;
> + INIT_LIST_HEAD(&xor_chan->submit_q);
> + INIT_LIST_HEAD(&xor_chan->pending_q);
> + INIT_LIST_HEAD(&xor_chan->in_progress_q);
> + INIT_LIST_HEAD(&xor_chan->free_desc);
> + spin_lock_init(&xor_chan->desc_lock);
> +
> + list_add_tail(&xor_chan->common.device_node, &dma_dev->channels);
> + dma_dev->chancnt++;
> +
> + err = dma_async_device_register(dma_dev);
> + if (err) {
> + dev_err(dev, "Unable to register XOR with Async_tx\n");
> + goto err_out;
Replace the jump with talitos_unregister_async_xor(dev) and
remove code under err_out label.
> + }
> +
> + return err;
> +
> +err_out:
> + talitos_unregister_async_xor(dev);
> + return err;
> +}
> +#endif
> diff --git a/drivers/crypto/talitos.h b/drivers/crypto/talitos.h
> index 61a1405..fc9d125 100644
> --- a/drivers/crypto/talitos.h
> +++ b/drivers/crypto/talitos.h
> @@ -30,6 +30,7 @@
>
> #define TALITOS_TIMEOUT 100000
> #define TALITOS_MAX_DATA_LEN 65535
> +#define TALITOS_MAX_DESCRIPTOR_NR 256
This refers only to xor descriptors, so renaming it similar to
TALITOS_MAX_XOR_DESCRIPTOR_NR would make sense.
Besides these:
1. As Dan Williams mentioned, you should explain why you are using
both spin_lock_bh and spin_lock_irqsave on the same lock.
2. I don't see anything added to talitos_remove(). Shouldn't
talitos_unregister_async_xor() be called? Anything else?
Have you tested with talitos built as a module?
Horia
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