On Fri, 2012-08-24 at 23:10 +0530, Naresh Kumar Inna wrote: > On 8/24/2012 1:18 AM, Nicholas A. Bellinger wrote: > > On Fri, 2012-08-24 at 03:57 +0530, Naresh Kumar Inna wrote: > >> This patch contains code to implement the interrupt handling and the fast > >> path I/O functionality. The interrupt handling includes allocation of > >> MSIX vectors, registering and implemeting the interrupt service routines. > >> The fast path I/O functionality includes posting the I/O request to > >> firmware > >> via Work Requests, tracking/completing them, and handling task management > >> requests. SCSI midlayer host template implementation is also covered by > >> this patch. > >> > >> Signed-off-by: Naresh Kumar Inna <nar...@chelsio.com> > >> --- > > > > Hi Naresh, > > > > My review comments are inline below.. > > Hi Nicholas, > > Thanks for taking the time to review the driver. Please find my replies > inline. > > Regards, > Naresh. > > > > >> drivers/scsi/csiostor/csio_isr.c | 631 ++++++++++ > >> drivers/scsi/csiostor/csio_scsi.c | 2498 > >> +++++++++++++++++++++++++++++++++++++ > >> 2 files changed, 3129 insertions(+), 0 deletions(-) > >> create mode 100644 drivers/scsi/csiostor/csio_isr.c > >> create mode 100644 drivers/scsi/csiostor/csio_scsi.c > >>
<SNIP> > > > >> diff --git a/drivers/scsi/csiostor/csio_scsi.c > >> b/drivers/scsi/csiostor/csio_scsi.c > >> new file mode 100644 > >> index 0000000..0f87b00 > >> --- /dev/null > >> +++ b/drivers/scsi/csiostor/csio_scsi.c > >> + > >> +#define CSIO_SCSI_CMD_WR_SZ(_imm) \ > >> + (sizeof(struct fw_scsi_cmd_wr) + /* WR size */ \ > >> + ALIGN((_imm), 16)) /* Immed data */ > >> + > >> +#define CSIO_SCSI_CMD_WR_SZ_16(_imm) > >> \ > >> + (ALIGN(CSIO_SCSI_CMD_WR_SZ((_imm)), 16)) > >> + > >> +/* > >> + * csio_scsi_cmd - Create a SCSI CMD WR. > >> + * @req: IO req structure. > >> + * > >> + * Gets a WR slot in the ingress queue and initializes it with SCSI CMD > >> WR. > >> + * > >> + */ > >> +static inline void > >> +csio_scsi_cmd(struct csio_ioreq *req) > >> +{ > >> + struct csio_wr_pair wrp; > >> + struct csio_hw *hw = req->lnode->hwp; > >> + struct csio_scsim *scsim = csio_hw_to_scsim(hw); > >> + uint32_t size = CSIO_SCSI_CMD_WR_SZ_16(scsim->proto_cmd_len); > >> + > >> + req->drv_status = csio_wr_get(hw, req->eq_idx, size, &wrp); > >> + if (unlikely(req->drv_status != CSIO_SUCCESS)) > >> + return; > >> + > >> + if (wrp.size1 >= size) { > >> + /* Initialize WR in one shot */ > >> + csio_scsi_init_cmd_wr(req, wrp.addr1, size); > >> + } else { > >> + uint8_t tmpwr[512]; > > > > Mmmm, putting this large of a buffer on the local stack is probably not > > a good idea. > > > > This should become an allocation.. If it's a hot path then you'll > > probably want to set this up before-hand. > > > > The else switch above is entered only when we near the end of the DMA > ring. This is not a frequent occurrence. If it is a strict no-no to have > so many on-stack bytes, I have to think of a way re-work it to use > pre-allocated memory. Please let me know. > Considering it's used a number of times, it would be better to just figure out a sensible manner to pre-allocate this, especially if it's only a single occurrence to an individual ring held under a lock. > >> + /* > >> + * Make a temporary copy of the WR and write back > >> + * the copy into the WR pair. > >> + */ > >> + csio_scsi_init_cmd_wr(req, (void *)tmpwr, size); > >> + memcpy(wrp.addr1, tmpwr, wrp.size1); > >> + memcpy(wrp.addr2, tmpwr + wrp.size1, size - wrp.size1); > >> + } > >> +} > >> + > >> +/* > >> + * The following is fast path code. Therefore it is inlined with > >> multi-line > >> + * macros using name substitution, thus avoiding if-else switches for > >> + * operation (read/write), as well as serving the purpose of code re-use. > >> + */ > >> +/* > >> + * csio_scsi_init_ulptx_dsgl - Fill in a ULP_TX_SC_DSGL > >> + * @hw: HW module > >> + * @req: IO request > >> + * @sgl: ULP TX SGL pointer. > >> + * > >> + */ > >> +#define csio_scsi_init_ultptx_dsgl(hw, req, sgl) \ > >> +do { > >> \ > >> + struct ulptx_sge_pair *_sge_pair = NULL; \ > >> + struct scatterlist *_sgel; \ > >> + uint32_t _i = 0; \ > >> + uint32_t _xfer_len; \ > >> + struct list_head *_tmp; \ > >> + struct csio_dma_buf *_dma_buf; \ > >> + struct scsi_cmnd *scmnd = csio_scsi_cmnd((req)); \ > >> + \ > >> + (sgl)->cmd_nsge = htonl(ULPTX_CMD(ULP_TX_SC_DSGL) | ULPTX_MORE | \ > >> + ULPTX_NSGE((req)->nsge)); \ > >> + /* Now add the data SGLs */ \ > >> + if (likely(!(req)->dcopy)) { \ > >> + scsi_for_each_sg(scmnd, _sgel, (req)->nsge, _i) { \ > >> + if (_i == 0) { \ > >> + (sgl)->addr0 = cpu_to_be64( \ > >> + sg_dma_address(_sgel)); \ > >> + (sgl)->len0 = cpu_to_be32( \ > >> + sg_dma_len(_sgel)); \ > >> + _sge_pair = \ > >> + (struct ulptx_sge_pair *)((sgl) + 1); \ > >> + continue; \ > >> + } \ > >> + if ((_i - 1) & 0x1) { \ > >> + _sge_pair->addr[1] = cpu_to_be64( \ > >> + sg_dma_address(_sgel)); \ > >> + _sge_pair->len[1] = cpu_to_be32( \ > >> + sg_dma_len(_sgel)); \ > >> + _sge_pair++; \ > >> + } else { \ > >> + _sge_pair->addr[0] = cpu_to_be64( \ > >> + sg_dma_address(_sgel)); \ > >> + _sge_pair->len[0] = cpu_to_be32( \ > >> + sg_dma_len(_sgel)); \ > >> + } \ > >> + } \ > >> + } else { \ > >> + /* Program sg elements with driver's DDP buffer */ \ > >> + _xfer_len = scsi_bufflen(scmnd); \ > >> + list_for_each(_tmp, &(req)->gen_list) { \ > >> + _dma_buf = (struct csio_dma_buf *)_tmp; \ > >> + if (_i == 0) { \ > >> + (sgl)->addr0 = cpu_to_be64(_dma_buf->paddr); \ > >> + (sgl)->len0 = cpu_to_be32( \ > >> + min(_xfer_len, _dma_buf->len)); \ > >> + _sge_pair = \ > >> + (struct ulptx_sge_pair *)((sgl) + 1); \ > >> + } \ > >> + else if ((_i - 1) & 0x1) { \ > >> + _sge_pair->addr[1] = cpu_to_be64( \ > >> + _dma_buf->paddr); \ > >> + _sge_pair->len[1] = cpu_to_be32( \ > >> + min(_xfer_len, _dma_buf->len)); \ > >> + _sge_pair++; \ > >> + } else { \ > >> + _sge_pair->addr[0] = cpu_to_be64( \ > >> + _dma_buf->paddr); \ > >> + _sge_pair->len[0] = cpu_to_be32( \ > >> + min(_xfer_len, _dma_buf->len)); \ > >> + } \ > >> + _xfer_len -= min(_xfer_len, _dma_buf->len); \ > >> + _i++; \ > >> + } \ > >> + } \ > >> +} while (0) > >> + > > > > I don't see any reason why this can't just be a static function..? Why > > is the macro usage necessary here..? > > OK, I will make this static-inline. > > > > >> +/* > >> + * csio_scsi_init_data_wr - Initialize the READ/WRITE SCSI WR. > >> + * @req: IO req structure. > >> + * @oper: read/write > >> + * @wrp: DMA location to place the payload. > >> + * @size: Size of WR (including FW WR + immed data + rsp SG entry + data > >> SGL > >> + * @wrop: _READ_/_WRITE_ > >> + * > >> + * Wrapper for populating fw_scsi_read_wr/fw_scsi_write_wr. > >> + */ > >> +#define csio_scsi_init_data_wr(req, oper, wrp, size, wrop) > >> \ > >> +do { > >> \ > >> + struct csio_hw *_hw = (req)->lnode->hwp; \ > >> + struct csio_rnode *_rn = (req)->rnode; \ > >> + struct fw_scsi_##oper##_wr *__wr = (struct fw_scsi_##oper##_wr *)(wrp);\ > >> + struct ulptx_sgl *_sgl; \ > >> + struct csio_dma_buf *_dma_buf; \ > >> + uint8_t _imm = csio_hw_to_scsim(_hw)->proto_cmd_len; \ > >> + struct scsi_cmnd *scmnd = csio_scsi_cmnd((req)); \ > >> + \ > >> + __wr->op_immdlen = cpu_to_be32(FW_WR_OP(FW_SCSI##wrop##WR) | \ > >> + FW_SCSI##wrop##WR_IMMDLEN(_imm)); \ > >> + __wr->flowid_len16 = cpu_to_be32(FW_WR_FLOWID(_rn->flowid) | \ > >> + FW_WR_LEN16( \ > >> + CSIO_ROUNDUP((size), 16))); \ > >> + __wr->cookie = (uintptr_t) (req); \ > >> + __wr->iqid = (uint16_t)cpu_to_be16(csio_q_physiqid(_hw, \ > >> + (req)->iq_idx));\ > >> + __wr->tmo_val = (uint8_t)((req)->tmo); \ > >> + __wr->use_xfer_cnt = 1; \ > >> + __wr->xfer_cnt = cpu_to_be32(scsi_bufflen(scmnd)); \ > >> + __wr->ini_xfer_cnt = cpu_to_be32(scsi_bufflen(scmnd)); \ > >> + /* Get RSP DMA buffer */ \ > >> + _dma_buf = &(req)->dma_buf; \ > >> + \ > >> + /* Prepare RSP SGL */ \ > >> + __wr->rsp_dmalen = cpu_to_be32(_dma_buf->len); \ > >> + __wr->rsp_dmaaddr = cpu_to_be64(_dma_buf->paddr); \ > >> + \ > >> + __wr->r4 = 0; \ > >> + \ > >> + __wr->u.fcoe.ctl_pri = 0; \ > >> + __wr->u.fcoe.cp_en_class = 0; \ > >> + __wr->u.fcoe.r3_lo[0] = 0; \ > >> + __wr->u.fcoe.r3_lo[1] = 0; \ > >> + csio_scsi_fcp_cmnd((req), (void *)((uintptr_t)(wrp) + \ > >> + sizeof(struct fw_scsi_##oper##_wr))); \ > >> + \ > >> + /* Move WR pointer past command and immediate data */ \ > >> + _sgl = (struct ulptx_sgl *) ((uintptr_t)(wrp) + \ > >> + sizeof(struct fw_scsi_##oper##_wr) + \ > >> + ALIGN(_imm, 16)); \ > >> + \ > >> + /* Fill in the DSGL */ \ > >> + csio_scsi_init_ultptx_dsgl(_hw, (req), _sgl); \ > >> + \ > >> +} while (0) > >> + > > > > This one has four uses of CPP keys. Just turn those into macros, and > > leave the rest of the code in a static function. > > > > So what you are suggesting is to have all the lines of the macro > csio_scsi_init_data_wr() added into a static function, but for the ones > with the 4 keys. csio_scsi_init_data_wr() will then invoke this new > function. Is that correct? > Not sure how the above should actually look without actually doing it, but IMHO the usage of macro just obfuscates what is going on.. If it's only used a few times, just inline the code into seperate static functions. If it's used more than a few times, then use a single static funciton with macro accessors for the assignment of the various '__wr' structure members. The larger problem with all of these macros is that you can't tell what is a macro and what is a function. If you need to use a CPP macro, please make sure to capitalize the name of the macro in order to tell the difference between the two. > >> +/* Calculate WR size needed for fw_scsi_read_wr/fw_scsi_write_wr */ > >> +#define csio_scsi_data_wrsz(req, oper, sz, imm) > >> \ > >> +do { > >> \ > >> + (sz) = sizeof(struct fw_scsi_##oper##_wr) + /* WR size */ \ > >> + ALIGN((imm), 16) + /* Immed data */ \ > >> + sizeof(struct ulptx_sgl); /* ulptx_sgl */ \ > >> + \ > >> + if (unlikely((req)->nsge > 1)) \ > >> + (sz) += (sizeof(struct ulptx_sge_pair) * \ > >> + (ALIGN(((req)->nsge - 1), 2) / 2)); \ > >> + /* Data SGE */ \ > >> +} while (0) > >> + > >> +/* > >> + * csio_scsi_data - Create a SCSI WRITE/READ WR. > >> + * @req: IO req structure. > >> + * @oper: read/write > >> + * @wrop: _READ_/_WRITE_ (string subsitutions to use with the FW bit > >> field > >> + * macros). > >> + * > >> + * Gets a WR slot in the ingress queue and initializes it with > >> + * SCSI CMD READ/WRITE WR. > >> + * > >> + */ > >> +#define csio_scsi_data(req, oper, wrop) > >> \ > >> +do { > >> \ > >> + struct csio_wr_pair _wrp; \ > >> + uint32_t _size; \ > >> + struct csio_hw *_hw = (req)->lnode->hwp; \ > >> + struct csio_scsim *_scsim = csio_hw_to_scsim(_hw); \ > >> + \ > >> + csio_scsi_data_wrsz((req), oper, _size, _scsim->proto_cmd_len); \ > >> + _size = ALIGN(_size, 16); \ > >> + \ > >> + (req)->drv_status = csio_wr_get(_hw, (req)->eq_idx, _size, &_wrp); \ > >> + if (likely((req)->drv_status == CSIO_SUCCESS)) { \ > >> + if (likely(_wrp.size1 >= _size)) { \ > >> + /* Initialize WR in one shot */ \ > >> + csio_scsi_init_data_wr((req), oper, _wrp.addr1, \ > >> + _size, wrop); \ > >> + } else { \ > >> + uint8_t tmpwr[512]; \ > >> + /* \ > >> + * Make a temporary copy of the WR and write back \ > >> + * the copy into the WR pair. \ > >> + */ \ > >> + csio_scsi_init_data_wr((req), oper, (void *)tmpwr, \ > >> + _size, wrop); \ > >> + memcpy(_wrp.addr1, tmpwr, _wrp.size1); \ > >> + memcpy(_wrp.addr2, tmpwr + _wrp.size1, \ > >> + _size - _wrp.size1); \ > >> + } \ > >> + } \ > >> +} while (0) > >> + > > > > Ditto on this one, along with the tmpwr[512] stack usage.. > > > >> +static inline void > >> +csio_scsi_abrt_cls(struct csio_ioreq *req, bool abort) > >> +{ > >> + struct csio_wr_pair wrp; > >> + struct csio_hw *hw = req->lnode->hwp; > >> + uint32_t size = ALIGN(sizeof(struct fw_scsi_abrt_cls_wr), 16); > >> + > >> + req->drv_status = csio_wr_get(hw, req->eq_idx, size, &wrp); > >> + if (req->drv_status != CSIO_SUCCESS) > >> + return; > >> + > >> + if (wrp.size1 >= size) { > >> + /* Initialize WR in one shot */ > >> + csio_scsi_init_abrt_cls_wr(req, wrp.addr1, size, abort); > >> + } else { > >> + uint8_t tmpwr[512]; > > > > Ditto here on local scope stack usage.. > > > >> + /* > >> + * Make a temporary copy of the WR and write back > >> + * the copy into the WR pair. > >> + */ > >> + csio_scsi_init_abrt_cls_wr(req, (void *)tmpwr, size, abort); > >> + memcpy(wrp.addr1, tmpwr, wrp.size1); > >> + memcpy(wrp.addr2, tmpwr + wrp.size1, size - wrp.size1); > >> + } > >> +} > >> + > >> +/*****************************************************************************/ > >> +/* START: SCSI SM > >> */ > >> +/*****************************************************************************/ > >> +static void > >> +csio_scsis_uninit(struct csio_ioreq *req, enum csio_scsi_ev evt) > >> +{ > >> + struct csio_hw *hw = req->lnode->hwp; > >> + struct csio_scsim *scsim = csio_hw_to_scsim(hw); > >> + > >> + switch (evt) { > >> + > >> + case CSIO_SCSIE_START_IO: > > > > Extra space between start of first switch case > > OK, I will remove it. Is there any tool that catches such deviations? > checkpath.pl didnt report it. > Sorry, can't help you there.. ;) > > > >> + > >> +/** > >> + * csio_queuecommand_lck - Entry point to kickstart an I/O request. > >> + * @cmnd: The I/O request from ML. > >> + * @done: The ML callback routine. > >> + * > >> + * This routine does the following: > >> + * - Checks for HW and Rnode module readiness. > >> + * - Gets a free ioreq structure (which is already initialized > >> + * to uninit during its allocation). > >> + * - Maps SG elements. > >> + * - Initializes ioreq members. > >> + * - Kicks off the SCSI state machine for this IO. > >> + * - Returns busy status on error. > >> + */ > >> +static int > >> +csio_queuecommand_lck(struct scsi_cmnd *cmnd, void (*done)(struct > >> scsi_cmnd *)) > >> +{ > >> + struct csio_lnode *ln = shost_priv(cmnd->device->host); > >> + struct csio_hw *hw = csio_lnode_to_hw(ln); > >> + struct csio_scsim *scsim = csio_hw_to_scsim(hw); > >> + struct csio_rnode *rn = (struct csio_rnode *)(cmnd->device->hostdata); > >> + struct csio_ioreq *ioreq = NULL; > >> + unsigned long flags; > >> + int nsge = 0; > >> + int rv = SCSI_MLQUEUE_HOST_BUSY, nr; > >> + csio_retval_t retval; > >> + int cpu; > >> + struct csio_scsi_qset *sqset; > >> + struct fc_rport *rport = starget_to_rport(scsi_target(cmnd->device)); > >> + > >> + if (!blk_rq_cpu_valid(cmnd->request)) > >> + cpu = smp_processor_id(); > >> + else > >> + cpu = cmnd->request->cpu; > >> + > >> + sqset = &hw->sqset[ln->portid][cpu]; > >> + > >> + nr = fc_remote_port_chkready(rport); > >> + if (nr) { > >> + cmnd->result = nr; > >> + csio_inc_stats(scsim, n_rn_nr_error); > >> + goto err_done; > >> + } > >> + > >> + if (unlikely(!csio_is_hw_ready(hw))) { > >> + cmnd->result = (DID_REQUEUE << 16); > >> + csio_inc_stats(scsim, n_hw_nr_error); > >> + goto err_done; > >> + } > >> + > >> + /* Get req->nsge, if there are SG elements to be mapped */ > >> + nsge = scsi_dma_map(cmnd); > >> + if (unlikely(nsge < 0)) { > >> + csio_inc_stats(scsim, n_dmamap_error); > >> + goto err; > >> + } > >> + > >> + /* Do we support so many mappings? */ > >> + if (unlikely(nsge > scsim->max_sge)) { > >> + csio_warn(hw, > >> + "More SGEs than can be supported." > >> + " SGEs: %d, Max SGEs: %d\n", nsge, scsim->max_sge); > >> + csio_inc_stats(scsim, n_unsupp_sge_error); > >> + goto err_dma_unmap; > >> + } > >> + > >> + /* Get a free ioreq structure - SM is already set to uninit */ > >> + ioreq = csio_get_scsi_ioreq_lock(hw, scsim); > >> + if (!ioreq) { > >> + csio_err(hw, "Out of I/O request elements. Active #:%d\n", > >> + scsim->stats.n_active); > >> + csio_inc_stats(scsim, n_no_req_error); > >> + goto err_dma_unmap; > >> + } > >> + > >> + ioreq->nsge = nsge; > >> + ioreq->lnode = ln; > >> + ioreq->rnode = rn; > >> + ioreq->iq_idx = sqset->iq_idx; > >> + ioreq->eq_idx = sqset->eq_idx; > >> + ioreq->wr_status = 0; > >> + ioreq->drv_status = CSIO_SUCCESS; > >> + csio_scsi_cmnd(ioreq) = (void *)cmnd; > >> + ioreq->tmo = 0; > >> + > >> + switch (cmnd->sc_data_direction) { > >> + case DMA_BIDIRECTIONAL: > >> + ioreq->datadir = CSIO_IOREQF_DMA_BIDI; > >> + csio_inc_stats(ln, n_control_requests); > >> + break; > >> + case DMA_TO_DEVICE: > >> + ioreq->datadir = CSIO_IOREQF_DMA_WRITE; > >> + csio_inc_stats(ln, n_output_requests); > >> + ln->stats.n_output_bytes += scsi_bufflen(cmnd); > >> + break; > >> + case DMA_FROM_DEVICE: > >> + ioreq->datadir = CSIO_IOREQF_DMA_READ; > >> + csio_inc_stats(ln, n_input_requests); > >> + ln->stats.n_input_bytes += scsi_bufflen(cmnd); > >> + break; > >> + case DMA_NONE: > >> + ioreq->datadir = CSIO_IOREQF_DMA_NONE; > >> + csio_inc_stats(ln, n_control_requests); > >> + break; > >> + default: > >> + CSIO_DB_ASSERT(0); > >> + break; > >> + } > >> + > >> + /* Set cbfn */ > >> + ioreq->io_cbfn = csio_scsi_cbfn; > >> + > >> + /* Needed during abort */ > >> + cmnd->host_scribble = (unsigned char *)ioreq; > >> + cmnd->scsi_done = done; > >> + cmnd->SCp.Message = 0; > >> + > >> + /* Kick off SCSI IO SM on the ioreq */ > >> + spin_lock_irqsave(&hw->lock, flags); > >> + retval = csio_scsi_start_io(ioreq); > >> + spin_unlock_irqrestore(&hw->lock, flags); > >> + > >> + if (retval != CSIO_SUCCESS) { > >> + csio_err(hw, "ioreq: %p couldnt be started, status:%d\n", > >> + ioreq, retval); > >> + csio_inc_stats(scsim, n_busy_error); > >> + goto err_put_req; > >> + } > >> + > >> + return 0; > >> + > >> +err_put_req: > >> + csio_put_scsi_ioreq_lock(hw, scsim, ioreq); > >> +err_dma_unmap: > >> + if (nsge > 0) > >> + scsi_dma_unmap(cmnd); > >> +err: > >> + return rv; > >> + > >> +err_done: > >> + done(cmnd); > >> + return 0; > >> +} > >> + > >> +static DEF_SCSI_QCMD(csio_queuecommand); > >> + > > > > This means that your running with the host_lock held.. I'm not sure if > > that is really what you want to do as it really end's up killing > > multi-lun small packet performance.. > > > > How about dropping DEF_SCSI_QCMD usage here, and figure out what > > actually needs to be protected by the SCSI host_lock within > > csio_queuecommand_lck()..? > > It is on my TODO list for the next version of the driver, after the > initial submission. Per the current design, we shouldnt need the > host_lock to be held, but I would like to test this change thoroughly > before I submit it. > Sure, it's really quite easy to convert and these days the majority of high performance LLDs do run in host-lock-less mode. IIRC the libfc based FCoE initiator driver is doing this too.. -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html