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Message-ID: <20170205060657.GV19244@localhost>
Date: Sun, 5 Feb 2017 11:36:57 +0530
From: Vinod Koul <vinod.koul@...el.com>
To: Anup Patel <anup.patel@...adcom.com>
Cc: Rob Herring <robh+dt@...nel.org>,
Mark Rutland <mark.rutland@....com>,
Herbert Xu <herbert@...dor.apana.org.au>,
"David S . Miller" <davem@...emloft.net>,
Jassi Brar <jassisinghbrar@...il.com>,
Dan Williams <dan.j.williams@...el.com>,
Ray Jui <rjui@...adcom.com>,
Scott Branden <sbranden@...adcom.com>,
Jon Mason <jonmason@...adcom.com>,
Rob Rice <rob.rice@...adcom.com>,
bcm-kernel-feedback-list@...adcom.com, dmaengine@...r.kernel.org,
devicetree@...r.kernel.org, linux-arm-kernel@...ts.infradead.org,
linux-kernel@...r.kernel.org, linux-crypto@...r.kernel.org,
linux-raid@...r.kernel.org
Subject: Re: [PATCH 5/6] dmaengine: Add Broadcom SBA RAID driver
On Thu, Feb 02, 2017 at 10:17:15AM +0530, Anup Patel wrote:
> +config BCM_SBA_RAID
> + tristate "Broadcom SBA RAID engine support"
> + depends on (ARM64 && MAILBOX && RAID6_PQ) || COMPILE_TEST
> + select DMA_ENGINE
> + select DMA_ENGINE_RAID
> + select ASYNC_TX_ENABLE_CHANNEL_SWITCH
> + default ARCH_BCM_IPROC
whats with the funny alignement?
> +/* SBA command related defines */
> +#define SBA_TYPE_SHIFT 48
> +#define SBA_TYPE_MASK 0x3
> +#define SBA_TYPE_A 0x0
> +#define SBA_TYPE_B 0x2
> +#define SBA_TYPE_C 0x3
> +#define SBA_USER_DEF_SHIFT 32
> +#define SBA_USER_DEF_MASK 0xffff
> +#define SBA_R_MDATA_SHIFT 24
> +#define SBA_R_MDATA_MASK 0xff
> +#define SBA_C_MDATA_MS_SHIFT 18
> +#define SBA_C_MDATA_MS_MASK 0x3
> +#define SBA_INT_SHIFT 17
> +#define SBA_INT_MASK 0x1
> +#define SBA_RESP_SHIFT 16
> +#define SBA_RESP_MASK 0x1
> +#define SBA_C_MDATA_SHIFT 8
> +#define SBA_C_MDATA_MASK 0xff
> +#define SBA_CMD_SHIFT 0
> +#define SBA_CMD_MASK 0xf
> +#define SBA_CMD_ZERO_ALL_BUFFERS 0x8
> +#define SBA_CMD_LOAD_BUFFER 0x9
> +#define SBA_CMD_XOR 0xa
> +#define SBA_CMD_GALOIS_XOR 0xb
> +#define SBA_CMD_ZERO_BUFFER 0x4
> +#define SBA_CMD_WRITE_BUFFER 0xc
Try using BIT and GENMAST for hardware descriptions
> +
> +/* SBA C_MDATA helper macros */
> +#define SBA_C_MDATA_LOAD_VAL(__bnum0) ((__bnum0) & 0x3)
> +#define SBA_C_MDATA_WRITE_VAL(__bnum0) ((__bnum0) & 0x3)
> +#define SBA_C_MDATA_XOR_VAL(__bnum1, __bnum0) \
> + ({ u32 __v = ((__bnum0) & 0x3); \
> + __v |= ((__bnum1) & 0x3) << 2; \
> + __v; \
> + })
> +#define SBA_C_MDATA_PQ_VAL(__dnum, __bnum1, __bnum0) \
> + ({ u32 __v = ((__bnum0) & 0x3); \
> + __v |= ((__bnum1) & 0x3) << 2; \
> + __v |= ((__dnum) & 0x1f) << 5; \
> + __v; \
> + })
ah why are we usig complex macros, why can't these be simple functions..
> +#define SBA_C_MDATA_LS(__c_mdata_val) ((__c_mdata_val) & 0xff)
> +#define SBA_C_MDATA_MS(__c_mdata_val) (((__c_mdata_val) >> 8) & 0x3)
> +
> +/* Driver helper macros */
> +#define to_sba_request(tx) \
> + container_of(tx, struct sba_request, tx)
> +#define to_sba_device(dchan) \
> + container_of(dchan, struct sba_device, dma_chan)
> +
> +enum sba_request_state {
> + SBA_REQUEST_STATE_FREE = 1,
> + SBA_REQUEST_STATE_ALLOCED = 2,
> + SBA_REQUEST_STATE_PENDING = 3,
> + SBA_REQUEST_STATE_ACTIVE = 4,
> + SBA_REQUEST_STATE_COMPLETED = 5,
> + SBA_REQUEST_STATE_ABORTED = 6,
whats up with a very funny indentation setting, we use 8 chars.
Please re-read the Documentation/process/coding-style.rst
> +static int sba_alloc_chan_resources(struct dma_chan *dchan)
> +{
> + /*
> + * We only have one channel so we have pre-alloced
> + * channel resources. Over here we just return number
> + * of free request.
> + */
> + return sba_free_request_count(to_sba_device(dchan));
> +}
essentially you are not doing much, so you can skip it. Its an optional
call.
> +static void sba_free_chan_resources(struct dma_chan *dchan)
> +{
> + /*
> + * Channel resources are pre-alloced so we just free-up
> + * whatever we can so that we can re-use pre-alloced
> + * channel resources next time.
> + */
> + sba_cleanup_inflight_requests(to_sba_device(dchan));
well this one checks for pending requests as well, which shouldn't be there
when freeing a channel, something seems not quite right here..
> +static int sba_send_mbox_request(struct sba_device *sba,
> + struct sba_request *req)
> +{
> + int mchans_idx, ret = 0;
> +
> + /* Select mailbox channel in round-robin fashion */
> + mchans_idx = atomic_inc_return(&sba->mchans_current);
> + mchans_idx = mchans_idx % sba->mchans_count;
> +
> + /* Send batch message for the request */
> + req->bmsg.batch.msgs_queued = 0;
> + ret = mbox_send_message(sba->mchans[mchans_idx], &req->bmsg);
> + if (ret < 0) {
> + dev_info(sba->dev, "channel %d message %d (total %d)",
> + mchans_idx, req->bmsg.batch.msgs_queued,
> + req->bmsg.batch.msgs_count);
dev_err?
> + dev_err(sba->dev, "send message failed with error %d", ret);
> + return ret;
> + }
> + ret = req->bmsg.error;
> + if (ret < 0) {
> + dev_info(sba->dev,
> + "mbox channel %d message %d (total %d)",
> + mchans_idx, req->bmsg.batch.msgs_queued,
> + req->bmsg.batch.msgs_count);
same here
> +static dma_cookie_t sba_tx_submit(struct dma_async_tx_descriptor *tx)
> +{
> + unsigned long flags;
> + dma_cookie_t cookie;
> + struct sba_request *req;
> + struct sba_device *sba;
> +
> + if (unlikely(!tx))
> + return -EINVAL;
> +
> + sba = to_sba_device(tx->chan);
> + req = to_sba_request(tx);
> +
> + /* Assign cookie and mark request pending */
> + spin_lock_irqsave(&sba->reqs_lock, flags);
> + cookie = dma_cookie_assign(tx);
> + _sba_pending_request(sba, req);
> + spin_unlock_irqrestore(&sba->reqs_lock, flags);
> +
> + /* Try to submit pending request */
> + sba_issue_pending(&sba->dma_chan);
Nope, thats wrong, caller needs to call .issue_pending for that
> +static enum dma_status sba_tx_status(struct dma_chan *dchan,
> + dma_cookie_t cookie,
> + struct dma_tx_state *txstate)
> +{
> + int mchan_idx;
> + enum dma_status ret;
> + struct sba_device *sba = to_sba_device(dchan);
> +
> + ret = dma_cookie_status(dchan, cookie, txstate);
> + if (ret == DMA_COMPLETE)
> + return ret;
> +
> + for (mchan_idx = 0; mchan_idx < sba->mchans_count; mchan_idx++)
> + mbox_client_peek_data(sba->mchans[mchan_idx]);
what is this achieving?
> +static struct dma_async_tx_descriptor *
> +sba_prep_dma_memcpy(struct dma_chan *dchan, dma_addr_t dst, dma_addr_t src,
> + size_t len, unsigned long flags)
> +{
> + size_t msg_len;
> + dma_addr_t msg_offset = 0;
> + unsigned int msgs_count = 0, cmds_count, cmds_idx = 0;
> + struct sba_device *sba = to_sba_device(dchan);
> + struct sba_request *req = NULL;
> +
> + /* Sanity checks */
> + if (unlikely(len > sba->req_size))
> + return NULL;
why is that an error, you can create multiple txn of max length
> +static int sba_async_register(struct sba_device *sba)
> +{
> + int ret;
> + struct dma_device *dma_dev = &sba->dma_dev;
> +
> + /* Initialize DMA channel cookie */
> + sba->dma_chan.device = dma_dev;
> + dma_cookie_init(&sba->dma_chan);
> +
> + /* Initialize DMA device capability mask */
> + dma_cap_zero(dma_dev->cap_mask);
> + dma_cap_set(DMA_MEMCPY, dma_dev->cap_mask);
> + dma_cap_set(DMA_XOR, dma_dev->cap_mask);
> + dma_cap_set(DMA_PQ, dma_dev->cap_mask);
> +
> + /*
> + * Set mailbox channel device as the base device of
> + * our dma_device because the actual memory accesses
> + * will be done by mailbox controller
> + */
> + dma_dev->dev = sba->mbox_dev;
> +
> + /* Set base prep routines */
> + dma_dev->device_alloc_chan_resources = sba_alloc_chan_resources;
> + dma_dev->device_free_chan_resources = sba_free_chan_resources;
> + dma_dev->device_issue_pending = sba_issue_pending;
> + dma_dev->device_tx_status = sba_tx_status;
Please add terminate callback support, also add the capabilities, we need to
advertise that and use in clients
Also you can simplify bunch of code by using virt-chan support for managing
channels and descriptors
--
~Vinod
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