Re: [dpdk-dev] [PATCH v3 4/6] raw/octeontx2_ep: add enqueue operation

[Mahipal Challa <mchalla@marvell.com>]

Hi Gavin,
Please see the response inline. 


> -----Original Message-----
> From: Gavin Hu <Gavin.Hu@arm.com>
> Sent: Tuesday, January 7, 2020 11:26 AM
> To: Mahipal Challa <mchalla@marvell.com>; dev@dpdk.org; Honnappa
> Nagarahalli <Honnappa.Nagarahalli@arm.com>
> Cc: Jerin Jacob Kollanukkaran <jerinj@marvell.com>; Narayana Prasad Raju
> Athreya <pathreya@marvell.com>; Subrahmanyam Nilla
> <snilla@marvell.com>; Venkateshwarlu Nalla <venkatn@marvell.com>; nd
> <nd@arm.com>
> Subject: [EXT] RE: [dpdk-dev] [PATCH v3 4/6] raw/octeontx2_ep: add
> enqueue operation
> 
> External Email
> 
> ----------------------------------------------------------------------
> Hi Mahipal,
> 
> > -----Original Message-----
> > From: Mahipal Challa <mchalla@marvell.com>
> > Sent: Monday, January 6, 2020 8:07 PM
> > To: dev@dpdk.org
> > Cc: jerinj@marvell.com; pathreya@marvell.com; snilla@marvell.com;
> > venkatn@marvell.com; Gavin Hu <Gavin.Hu@arm.com>
> > Subject: [dpdk-dev] [PATCH v3 4/6] raw/octeontx2_ep: add enqueue
> > operation
> >
> > Add rawdev enqueue operation for SDP VF devices.
> >
> > Signed-off-by: Mahipal Challa <mchalla@marvell.com>
> > ---
> >  doc/guides/rawdevs/octeontx2_ep.rst       |   6 +
> >  drivers/raw/octeontx2_ep/otx2_ep_enqdeq.c | 242
> > ++++++++++++++++++++++++++++++
> >  drivers/raw/octeontx2_ep/otx2_ep_enqdeq.h |  39 +++++
> >  drivers/raw/octeontx2_ep/otx2_ep_rawdev.c |   1 +
> >  drivers/raw/octeontx2_ep/otx2_ep_rawdev.h |  20 +++
> >  drivers/raw/octeontx2_ep/otx2_ep_vf.c     |  24 +++
> >  6 files changed, 332 insertions(+)
> >
> > diff --git a/doc/guides/rawdevs/octeontx2_ep.rst
> > b/doc/guides/rawdevs/octeontx2_ep.rst
> > index 2507fcf..39a7c29 100644
> > --- a/doc/guides/rawdevs/octeontx2_ep.rst
> > +++ b/doc/guides/rawdevs/octeontx2_ep.rst
> > @@ -68,3 +68,9 @@ The following code shows how the device is
> > configured
> >
> >     rte_rawdev_configure(dev_id, (rte_rawdev_obj_t)&rdev_info);
> >
> > +Performing Data Transfer
> > +------------------------
> > +
> > +To perform data transfer using SDP VF EP rawdev devices use standard
> > +``rte_rawdev_enqueue_buffers()`` and ``rte_rawdev_dequeue_buffers()``
> > APIs.
> > +
> > diff --git a/drivers/raw/octeontx2_ep/otx2_ep_enqdeq.c
> > b/drivers/raw/octeontx2_ep/otx2_ep_enqdeq.c
> > index 584b818..6910f08 100644
> > --- a/drivers/raw/octeontx2_ep/otx2_ep_enqdeq.c
> > +++ b/drivers/raw/octeontx2_ep/otx2_ep_enqdeq.c
> > @@ -403,3 +403,245 @@
> >  	return -ENOMEM;
> >  }
> >
> > +static inline void
> > +sdp_iqreq_delete(struct sdp_device *sdpvf,
> > +		struct sdp_instr_queue *iq, uint32_t idx) {
> > +	uint32_t reqtype;
> > +	void *buf;
> > +
> > +	buf     = iq->req_list[idx].buf;
> > +	reqtype = iq->req_list[idx].reqtype;
> > +
> > +	switch (reqtype) {
> > +	case SDP_REQTYPE_NORESP:
> > +		rte_mempool_put(sdpvf->enqdeq_mpool, buf);
> > +		otx2_sdp_dbg("IQ buffer freed at idx[%d]", idx);
> > +		break;
> > +
> > +	case SDP_REQTYPE_NORESP_GATHER:
> > +	case SDP_REQTYPE_NONE:
> > +	default:
> > +		otx2_info("This iqreq mode is not supported:%d", reqtype);
> > +
> > +	}
> > +
> > +	/* Reset the request list at this index */
> > +	iq->req_list[idx].buf = NULL;
> > +	iq->req_list[idx].reqtype = 0;
> > +}
> > +
> > +static inline void
> > +sdp_iqreq_add(struct sdp_instr_queue *iq, void *buf,
> > +		uint32_t reqtype)
> > +{
> > +	iq->req_list[iq->host_write_index].buf = buf;
> > +	iq->req_list[iq->host_write_index].reqtype = reqtype;
> > +
> > +	otx2_sdp_dbg("IQ buffer added at idx[%d]", iq->host_write_index);
> > +
> > +}
> > +
> > +static void
> > +sdp_flush_iq(struct sdp_device *sdpvf,
> > +		struct sdp_instr_queue *iq,
> > +		uint32_t pending_thresh __rte_unused) {
> > +	uint32_t instr_processed = 0;
> > +
> > +	rte_spinlock_lock(&iq->lock);
> > +
> > +	iq->otx_read_index = sdpvf->fn_list.update_iq_read_idx(iq);
> > +	while (iq->flush_index != iq->otx_read_index) {
> > +		/* Free the IQ data buffer to the pool */
> > +		sdp_iqreq_delete(sdpvf, iq, iq->flush_index);
> > +		iq->flush_index =
> > +			sdp_incr_index(iq->flush_index, 1, iq->nb_desc);
> > +
> > +		instr_processed++;
> > +	}
> > +
> > +	iq->stats.instr_processed = instr_processed;
> > +	rte_atomic64_sub(&iq->instr_pending, instr_processed);
> > +
> > +	rte_spinlock_unlock(&iq->lock);
> > +}
> > +
> > +static inline void
> > +sdp_ring_doorbell(struct sdp_device *sdpvf __rte_unused,
> > +		struct sdp_instr_queue *iq)
> > +{
> > +	otx2_write64(iq->fill_cnt, iq->doorbell_reg);
> > +
> > +	/* Make sure doorbell write goes through */
> > +	rte_cio_wmb();
> I think I commented this in v2.
> The barrier should be hoisted up in between the two memory accesses which
> you want a definite ordering, by CPU or NIC or both.
> I does not guarantee "going through" or completeness(maybe "dsb" can, as it
> stalls execution until the preceding memory access instruction complete, but
> that is from the point of CPU, not the memory. The early acknowledge
> mechanism will induce the CPU to think it is done but in reality it does mean
> to arrive at the memory, especially the IO device registers).
> 
[Mahipal]: This is just for IO device, so observed ordering is suffice. That is the reason we have changed this from "rte_wmb" to "rte_cio_wmb" as per your suggestion in v1.

> Anyway I am not against the comments mentioning "completeness" for "dsb"
> based barriers, but for io and cio barriers, they are about observed ordering,
> not about "completeness".

[Mahipal]: Will modify the comment accordingly in v4.

> > +	iq->fill_cnt = 0;
> > +
> > +}
> > +
> > +static inline int
> > +post_iqcmd(struct sdp_instr_queue *iq, uint8_t *iqcmd) {
> > +	uint8_t *iqptr, cmdsize;
> > +
> > +	/* This ensures that the read index does not wrap around to
> > +	 * the same position if queue gets full before OCTEON TX2 could
> > +	 * fetch any instr.
> > +	 */
> > +	if (rte_atomic64_read(&iq->instr_pending) >=
> > +			      (int32_t)(iq->nb_desc - 1)) {
> > +		otx2_err("IQ is full, pending:%ld",
> > +			 (long)rte_atomic64_read(&iq->instr_pending));
> > +
> > +		return SDP_IQ_SEND_FAILED;
> > +	}
> > +
> > +	/* Copy cmd into iq */
> > +	cmdsize = ((iq->iqcmd_64B) ? 64 : 32);
> > +	iqptr   = iq->base_addr + (cmdsize * iq->host_write_index);
> > +
> > +	rte_memcpy(iqptr, iqcmd, cmdsize);
> > +
> > +	otx2_sdp_dbg("IQ cmd posted @ index:%d", iq->host_write_index);
> > +
> > +	/* Increment the host write index */
> > +	iq->host_write_index =
> > +		sdp_incr_index(iq->host_write_index, 1, iq->nb_desc);
> > +
> > +	iq->fill_cnt++;
> > +
> > +	/* Flush the command into memory. We need to be sure the data
> > +	 * is in memory before indicating that the instruction is
> > +	 * pending.
> > +	 */
> > +	rte_io_wmb();
> If both memory accesses are in normal memory, then rte_smp_wmb should
> be used.

[Mahipal]: ACK, will replace it with rte_smp_wmb() API.


> > +	rte_atomic64_inc(&iq->instr_pending);
> > +
> > +	/* SDP_IQ_SEND_SUCCESS */
> > +	return 0;
> > +}
> > +
> > +
> > +static int
> > +sdp_send_data(struct sdp_device *sdpvf,
> > +	      struct sdp_instr_queue *iq, void *cmd) {
> > +	uint32_t ret;
> > +
> > +	/* Lock this IQ command queue before posting instruction */
> > +	rte_spinlock_lock(&iq->post_lock);
> > +
> > +	/* Submit IQ command */
> > +	ret = post_iqcmd(iq, cmd);
> > +
> > +	if (ret == SDP_IQ_SEND_SUCCESS) {
> > +		sdp_ring_doorbell(sdpvf, iq);
> > +
> > +		iq->stats.instr_posted++;
> > +		otx2_sdp_dbg("Instr submit success posted: %ld\n",
> > +			     (long)iq->stats.instr_posted);
> > +
> > +	} else {
> > +		iq->stats.instr_dropped++;
> > +		otx2_err("Instr submit failled, dropped: %ld\n",
> > +			 (long)iq->stats.instr_dropped);
> > +
> > +	}
> > +
> > +	rte_spinlock_unlock(&iq->post_lock);
> > +
> > +	return ret;
> > +}
> > +
> > +
> > +/* Enqueue requests/packets to SDP IQ queue.
> > + * returns number of requests enqueued successfully  */ int
> > +sdp_rawdev_enqueue(struct rte_rawdev *rawdev,
> > +		   struct rte_rawdev_buf **buffers __rte_unused,
> > +		   unsigned int count, rte_rawdev_obj_t context) {
> > +	struct sdp_instr_64B *iqcmd;
> > +	struct sdp_instr_queue *iq;
> > +	struct sdp_soft_instr *si;
> > +	struct sdp_device *sdpvf;
> > +
> > +	struct sdp_instr_ih ihx;
> > +
> > +	sdpvf = (struct sdp_device *)rawdev->dev_private;
> > +	si = (struct sdp_soft_instr *)context;
> > +
> > +	iq = sdpvf->instr_queue[si->q_no];
> > +
> > +	if ((count > 1) || (count < 1)) {
> > +		otx2_err("This mode not supported: req[%d]", count);
> > +		goto enq_fail;
> > +	}
> > +
> > +	memset(&ihx, 0, sizeof(struct sdp_instr_ih));
> > +
> > +	iqcmd = &si->command;
> > +	memset(iqcmd, 0, sizeof(struct sdp_instr_64B));
> > +
> > +	iqcmd->dptr = (uint64_t)si->dptr;
> > +
> > +	/* Populate SDP IH */
> > +	ihx.pkind  = sdpvf->pkind;
> > +	ihx.fsz    = si->ih.fsz + 8; /* 8B for NIX IH */
> > +	ihx.gather = si->ih.gather;
> > +
> > +	/* Direct data instruction */
> > +	ihx.tlen   = si->ih.tlen + ihx.fsz;
> > +
> > +	switch (ihx.gather) {
> > +	case 0: /* Direct data instr */
> > +		ihx.tlen = si->ih.tlen + ihx.fsz;
> > +		break;
> > +
> > +	default: /* Gather */
> > +		switch (si->ih.gsz) {
> > +		case 0: /* Direct gather instr */
> > +			otx2_err("Direct Gather instr : not supported");
> > +			goto enq_fail;
> > +
> > +		default: /* Indirect gather instr */
> > +			otx2_err("Indirect Gather instr : not supported");
> > +			goto enq_fail;
> > +		}
> > +	}
> > +
> > +	rte_memcpy(&iqcmd->ih, &ihx, sizeof(uint64_t));
> > +	iqcmd->rptr = (uint64_t)si->rptr;
> > +	rte_memcpy(&iqcmd->irh, &si->irh, sizeof(uint64_t));
> > +
> > +	/* Swap FSZ(front data) here, to avoid swapping on OCTEON TX2 side
> > */
> > +	sdp_swap_8B_data(&iqcmd->rptr, 1);
> > +	sdp_swap_8B_data(&iqcmd->irh, 1);
> > +
> > +	otx2_sdp_dbg("After swapping");
> > +	otx2_sdp_dbg("Word0 [dptr]: 0x%016lx", (unsigned long)iqcmd-
> > >dptr);
> > +	otx2_sdp_dbg("Word1 [ihtx]: 0x%016lx", (unsigned long)iqcmd->ih);
> > +	otx2_sdp_dbg("Word2 [rptr]: 0x%016lx", (unsigned long)iqcmd-
> >rptr);
> > +	otx2_sdp_dbg("Word3 [irh]: 0x%016lx", (unsigned long)iqcmd->irh);
> > +	otx2_sdp_dbg("Word4 [exhdr[0]]: 0x%016lx",
> > +			(unsigned long)iqcmd->exhdr[0]);
> > +
> > +	sdp_iqreq_add(iq, si->dptr, si->reqtype);
> > +
> > +	if (sdp_send_data(sdpvf, iq, iqcmd)) {
> > +		otx2_err("Data send failled :");
> > +		sdp_iqreq_delete(sdpvf, iq, iq->host_write_index);
> > +		goto enq_fail;
> > +	}
> > +
> > +	if (rte_atomic64_read(&iq->instr_pending) >= 1)
> > +		sdp_flush_iq(sdpvf, iq, 1 /*(iq->nb_desc / 2)*/);
> > +
> > +	/* Return no# of instructions posted successfully. */
> > +	return count;
> > +
> > +enq_fail:
> > +	return SDP_IQ_SEND_FAILED;
> > +}
> > +
> > diff --git a/drivers/raw/octeontx2_ep/otx2_ep_enqdeq.h
> > b/drivers/raw/octeontx2_ep/otx2_ep_enqdeq.h
> > index 4c28283..b9b7c0b 100644
> > --- a/drivers/raw/octeontx2_ep/otx2_ep_enqdeq.h
> > +++ b/drivers/raw/octeontx2_ep/otx2_ep_enqdeq.h
> > @@ -8,4 +8,43 @@
> >  #include <rte_byteorder.h>
> >  #include "otx2_ep_rawdev.h"
> >
> > +#define SDP_IQ_SEND_FAILED      (-1)
> > +#define SDP_IQ_SEND_SUCCESS     (0)
> > +
> > +
> > +static inline uint64_t
> > +sdp_endian_swap_8B(uint64_t _d)
> > +{
> > +	return ((((((uint64_t)(_d)) >>  0) & (uint64_t)0xff) << 56) |
> > +		(((((uint64_t)(_d)) >>  8) & (uint64_t)0xff) << 48) |
> > +		(((((uint64_t)(_d)) >> 16) & (uint64_t)0xff) << 40) |
> > +		(((((uint64_t)(_d)) >> 24) & (uint64_t)0xff) << 32) |
> > +		(((((uint64_t)(_d)) >> 32) & (uint64_t)0xff) << 24) |
> > +		(((((uint64_t)(_d)) >> 40) & (uint64_t)0xff) << 16) |
> > +		(((((uint64_t)(_d)) >> 48) & (uint64_t)0xff) <<  8) |
> > +		(((((uint64_t)(_d)) >> 56) & (uint64_t)0xff) <<  0)); }
> > +
> > +static inline void
> > +sdp_swap_8B_data(uint64_t *data, uint32_t blocks) {
> > +	/* Swap 8B blocks */
> > +	while (blocks) {
> > +		*data = sdp_endian_swap_8B(*data);
> > +		blocks--;
> > +		data++;
> > +	}
> > +}
> > +
> > +static inline uint32_t
> > +sdp_incr_index(uint32_t index, uint32_t count, uint32_t max) {
> > +	if ((index + count) >= max)
> > +		index = index + count - max;
> > +	else
> > +		index += count;
> > +
> > +	return index;
> > +}
> > +
> >  #endif /* _OTX2_EP_ENQDEQ_H_ */
> > diff --git a/drivers/raw/octeontx2_ep/otx2_ep_rawdev.c
> > b/drivers/raw/octeontx2_ep/otx2_ep_rawdev.c
> > index 3db5a74..22a6beb 100644
> > --- a/drivers/raw/octeontx2_ep/otx2_ep_rawdev.c
> > +++ b/drivers/raw/octeontx2_ep/otx2_ep_rawdev.c
> > @@ -251,6 +251,7 @@
> >  	.dev_start      = sdp_rawdev_start,
> >  	.dev_stop       = sdp_rawdev_stop,
> >  	.dev_close      = sdp_rawdev_close,
> > +	.enqueue_bufs   = sdp_rawdev_enqueue,
> >  };
> >
> >  static int
> > diff --git a/drivers/raw/octeontx2_ep/otx2_ep_rawdev.h
> > b/drivers/raw/octeontx2_ep/otx2_ep_rawdev.h
> > index a01f48d..8fd06fb 100644
> > --- a/drivers/raw/octeontx2_ep/otx2_ep_rawdev.h
> > +++ b/drivers/raw/octeontx2_ep/otx2_ep_rawdev.h
> > @@ -8,6 +8,10 @@
> >  #include <rte_byteorder.h>
> >  #include <rte_spinlock.h>
> >
> > +/* IQ instruction req types */
> > +#define SDP_REQTYPE_NONE             (0)
> > +#define SDP_REQTYPE_NORESP           (1)
> > +#define SDP_REQTYPE_NORESP_GATHER    (2)
> >
> >  /* Input Request Header format */
> >  struct sdp_instr_irh {
> > @@ -128,6 +132,13 @@ struct sdp_instr_list {  };
> >  #define SDP_IQREQ_LIST_SIZE	(sizeof(struct sdp_instr_list))
> >
> > +/* Input Queue statistics. Each input queue has four stats fields. */
> > +struct sdp_iq_stats {
> > +	uint64_t instr_posted; /* Instructions posted to this queue. */
> > +	uint64_t instr_processed; /* Instructions processed in this queue. */
> > +	uint64_t instr_dropped; /* Instructions that could not be processed
> > +*/ };
> > +
> >  /* Structure to define the configuration attributes for each Input
> > queue. */  struct sdp_iq_config {
> >  	/* Max number of IQs available */
> > @@ -195,6 +206,9 @@ struct sdp_instr_queue {
> >  	/* Number of instructions pending to be posted to OCTEON TX2. */
> >  	uint32_t fill_cnt;
> >
> > +	/* Statistics for this input queue. */
> > +	struct sdp_iq_stats stats;
> > +
> >  	/* DMA mapped base address of the input descriptor ring. */
> >  	uint64_t base_addr_dma;
> >
> > @@ -380,6 +394,8 @@ struct sdp_fn_list {
> >  	void (*setup_oq_regs)(struct sdp_device *sdpvf, uint32_t q_no);
> >
> >  	int (*setup_device_regs)(struct sdp_device *sdpvf);
> > +	uint32_t (*update_iq_read_idx)(struct sdp_instr_queue *iq);
> > +
> >  	void (*enable_io_queues)(struct sdp_device *sdpvf);
> >  	void (*disable_io_queues)(struct sdp_device *sdpvf);
> >
> > @@ -458,4 +474,8 @@ struct sdp_device {  int sdp_setup_oqs(struct
> > sdp_device *sdpvf, uint32_t oq_no);  int sdp_delete_oqs(struct
> > sdp_device *sdpvf, uint32_t oq_no);
> >
> > +int sdp_rawdev_enqueue(struct rte_rawdev *dev, struct rte_rawdev_buf
> > **buffers,
> > +		       unsigned int count, rte_rawdev_obj_t context);
> > +
> > +
> >  #endif /* _OTX2_EP_RAWDEV_H_ */
> > diff --git a/drivers/raw/octeontx2_ep/otx2_ep_vf.c
> > b/drivers/raw/octeontx2_ep/otx2_ep_vf.c
> > index 8e79fe8..c5c0bc3 100644
> > --- a/drivers/raw/octeontx2_ep/otx2_ep_vf.c
> > +++ b/drivers/raw/octeontx2_ep/otx2_ep_vf.c
> > @@ -409,6 +409,28 @@
> >  		sdp_vf_disable_oq(sdpvf, q_no);
> >  }
> >
> > +static uint32_t
> > +sdp_vf_update_read_index(struct sdp_instr_queue *iq) {
> > +	uint32_t new_idx = rte_read32(iq->inst_cnt_reg);
> > +
> > +	/* The new instr cnt reg is a 32-bit counter that can roll over.
> > +	 * We have noted the counter's initial value at init time into
> > +	 * reset_instr_cnt
> > +	 */
> > +	if (iq->reset_instr_cnt < new_idx)
> > +		new_idx -= iq->reset_instr_cnt;
> > +	else
> > +		new_idx += (0xffffffff - iq->reset_instr_cnt) + 1;
> > +
> > +	/* Modulo of the new index with the IQ size will give us
> > +	 * the new index.
> > +	 */
> > +	new_idx %= iq->nb_desc;
> > +
> > +	return new_idx;
> > +}
> > +
> >  int
> >  sdp_vf_setup_device(struct sdp_device *sdpvf)  { @@ -436,6 +458,8 @@
> >  	sdpvf->fn_list.setup_oq_regs       = sdp_vf_setup_oq_regs;
> >
> >  	sdpvf->fn_list.setup_device_regs   = sdp_vf_setup_device_regs;
> > +	sdpvf->fn_list.update_iq_read_idx  = sdp_vf_update_read_index;
> > +
> >  	sdpvf->fn_list.enable_io_queues    = sdp_vf_enable_io_queues;
> >  	sdpvf->fn_list.disable_io_queues   = sdp_vf_disable_io_queues;
> >
> > --
> > 1.8.3.1

Thanks,
Mahipal