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From: Laurent Vivier <laurent@vivier.eu>
To: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>,
	qemu-devel@nongnu.org, pbonzini@redhat.com, fam@euphon.net
Subject: Re: [PATCH v2 28/42] esp: use FIFO for PDMA transfers between initiator and device
Date: Tue, 2 Mar 2021 23:02:16 +0100	[thread overview]
Message-ID: <ccd7eacd-7bff-0eb1-5f49-e6a2c9eac552@vivier.eu> (raw)
In-Reply-To: <20210209193018.31339-29-mark.cave-ayland@ilande.co.uk>

Le 09/02/2021 à 20:30, Mark Cave-Ayland a écrit :
> PDMA as implemented on the Quadra 800 uses DREQ to load data into the FIFO
> up to a maximum of 16 bytes at a time. The MacOS toolbox ROM requires this
> because it mixes FIFO and PDMA transfers whilst checking the FIFO status
> and counter registers to ensure success.
> 
> Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
> ---
>  hw/scsi/esp.c | 109 ++++++++++++++++++++++++++++++++++----------------
>  1 file changed, 75 insertions(+), 34 deletions(-)
> 
> diff --git a/hw/scsi/esp.c b/hw/scsi/esp.c
> index b7ab5a5592..5dcd4cd651 100644
> --- a/hw/scsi/esp.c
> +++ b/hw/scsi/esp.c
> @@ -134,13 +134,8 @@ static void set_pdma(ESPState *s, enum pdma_origin_id origin)
>  
>  static uint8_t esp_pdma_read(ESPState *s)
>  {
> -    uint32_t dmalen = esp_get_tc(s);
>      uint8_t val;
>  
> -    if (dmalen == 0) {
> -        return 0;
> -    }
> -
>      switch (s->pdma_origin) {
>      case TI:
>          if (s->do_cmd) {
> @@ -160,10 +155,6 @@ static uint8_t esp_pdma_read(ESPState *s)
>          g_assert_not_reached();
>      }
>  
> -    s->ti_size--;
> -    dmalen--;
> -    esp_set_tc(s, dmalen);
> -
>      return val;
>  }
>  
> @@ -194,7 +185,6 @@ static void esp_pdma_write(ESPState *s, uint8_t val)
>          g_assert_not_reached();
>      }
>  
> -    s->ti_size++;
>      dmalen--;
>      esp_set_tc(s, dmalen);
>  }
> @@ -290,6 +280,7 @@ static void do_busid_cmd(ESPState *s, uint8_t *buf, uint8_t busid)
>      s->rregs[ESP_RINTR] = INTR_BS | INTR_FC;
>      s->rregs[ESP_RSEQ] = SEQ_CD;
>      esp_raise_irq(s);
> +    esp_lower_drq(s);
>  }
>  
>  static void do_cmd(ESPState *s)
> @@ -447,28 +438,71 @@ static void esp_dma_done(ESPState *s)
>  static void do_dma_pdma_cb(ESPState *s)
>  {
>      int to_device = ((s->rregs[ESP_RSTAT] & 7) == STAT_DO);
> +    int len;
>  
>      if (s->do_cmd) {
>          s->ti_size = 0;
>          s->cmdlen = 0;
>          s->do_cmd = 0;
>          do_cmd(s);
> +        esp_lower_drq(s);
>          return;
>      }
> -    if (s->async_len == 0) {
> -        scsi_req_continue(s->current_req);
> -        /*
> -         * If there is still data to be read from the device then
> -         * complete the DMA operation immediately.  Otherwise defer
> -         * until the scsi layer has completed.
> -         */
> -        if (to_device || esp_get_tc(s) != 0 || s->ti_size == 0) {
> +
> +    if (to_device) {
> +        /* Copy FIFO data to device */
> +        len = MIN(s->ti_wptr, TI_BUFSZ);
> +        memcpy(s->async_buf, s->ti_buf, len);
> +        s->ti_wptr = 0;
> +        s->ti_rptr = 0;
> +        s->async_buf += len;
> +        s->async_len -= len;
> +        s->ti_size += len;
> +        if (s->async_len == 0) {
> +            scsi_req_continue(s->current_req);
>              return;
>          }
> -    }
>  
> -    /* Partially filled a scsi buffer. Complete immediately.  */
> -    esp_dma_done(s);
> +        if (esp_get_tc(s) == 0) {
> +            esp_lower_drq(s);
> +            esp_dma_done(s);
> +        }
> +
> +        return;
> +    } else {
> +        if (s->async_len == 0) {
> +            if (s->current_req) {
> +                scsi_req_continue(s->current_req);
> +            }
> +
> +            /*
> +             * If there is still data to be read from the device then
> +             * complete the DMA operation immediately.  Otherwise defer
> +             * until the scsi layer has completed.
> +             */
> +            if (esp_get_tc(s) != 0 || s->ti_size == 0) {
> +                return;
> +            }
> +        }
> +
> +        if (esp_get_tc(s) != 0) {
> +            /* Copy device data to FIFO */
> +            s->ti_wptr = 0;
> +            s->ti_rptr = 0;
> +            len = MIN(s->async_len, TI_BUFSZ);
> +            memcpy(s->ti_buf, s->async_buf, len);
> +            s->ti_wptr += len;
> +            s->async_buf += len;
> +            s->async_len -= len;
> +            s->ti_size -= len;
> +            esp_set_tc(s, esp_get_tc(s) - len);
> +            return;
> +        }
> +
> +        /* Partially filled a scsi buffer. Complete immediately.  */
> +        esp_lower_drq(s);
> +        esp_dma_done(s);
> +    }
>  }
>  
>  static void esp_do_dma(ESPState *s)
> @@ -511,7 +545,7 @@ static void esp_do_dma(ESPState *s)
>          if (s->dma_memory_read) {
>              s->dma_memory_read(s->dma_opaque, s->async_buf, len);
>          } else {
> -            set_pdma(s, ASYNC);
> +            set_pdma(s, TI);
>              s->pdma_cb = do_dma_pdma_cb;
>              esp_raise_drq(s);
>              return;
> @@ -520,9 +554,20 @@ static void esp_do_dma(ESPState *s)
>          if (s->dma_memory_write) {
>              s->dma_memory_write(s->dma_opaque, s->async_buf, len);
>          } else {
> -            set_pdma(s, ASYNC);
> +            /* Copy device data to FIFO */
> +            len = MIN(len, TI_BUFSZ - s->ti_wptr);
> +            memcpy(&s->ti_buf[s->ti_wptr], s->async_buf, len);
> +            s->ti_wptr += len;
> +            s->async_buf += len;
> +            s->async_len -= len;
> +            s->ti_size -= len;
> +            esp_set_tc(s, esp_get_tc(s) - len);
> +            set_pdma(s, TI);
>              s->pdma_cb = do_dma_pdma_cb;
>              esp_raise_drq(s);
> +
> +            /* Indicate transfer to FIFO is complete */
> +            s->rregs[ESP_RSTAT] |= STAT_TC;
>              return;
>          }
>      }
> @@ -548,6 +593,7 @@ static void esp_do_dma(ESPState *s)
>  
>      /* Partially filled a scsi buffer. Complete immediately.  */
>      esp_dma_done(s);
> +    esp_lower_drq(s);
>  }
>  
>  static void esp_report_command_complete(ESPState *s, uint32_t status)
> @@ -564,6 +610,7 @@ static void esp_report_command_complete(ESPState *s, uint32_t status)
>      s->status = status;
>      s->rregs[ESP_RSTAT] = STAT_ST;
>      esp_dma_done(s);
> +    esp_lower_drq(s);
>      if (s->current_req) {
>          scsi_req_unref(s->current_req);
>          s->current_req = NULL;
> @@ -606,6 +653,7 @@ void esp_transfer_data(SCSIRequest *req, uint32_t len)
>           * completion interrupt is deferred to here.
>           */
>          esp_dma_done(s);
> +        esp_lower_drq(s);
>      }
>  }
>  
> @@ -977,10 +1025,8 @@ static void sysbus_esp_pdma_write(void *opaque, hwaddr addr,
>          break;
>      }
>      dmalen = esp_get_tc(s);
> -    if (dmalen == 0 && s->pdma_cb) {
> -        esp_lower_drq(s);
> +    if (dmalen == 0 || (s->ti_wptr == TI_BUFSZ)) {
>          s->pdma_cb(s);
> -        s->pdma_cb = NULL;
>      }
>  }
>  
> @@ -989,14 +1035,10 @@ static uint64_t sysbus_esp_pdma_read(void *opaque, hwaddr addr,
>  {
>      SysBusESPState *sysbus = opaque;
>      ESPState *s = ESP(&sysbus->esp);
> -    uint32_t dmalen = esp_get_tc(s);
>      uint64_t val = 0;
>  
>      trace_esp_pdma_read(size);
>  
> -    if (dmalen == 0) {
> -        return 0;
> -    }
>      switch (size) {
>      case 1:
>          val = esp_pdma_read(s);
> @@ -1006,11 +1048,10 @@ static uint64_t sysbus_esp_pdma_read(void *opaque, hwaddr addr,
>          val = (val << 8) | esp_pdma_read(s);
>          break;
>      }
> -    dmalen = esp_get_tc(s);
> -    if (dmalen == 0 && s->pdma_cb) {
> -        esp_lower_drq(s);
> +    if (s->ti_rptr == s->ti_wptr) {
> +        s->ti_wptr = 0;
> +        s->ti_rptr = 0;
>          s->pdma_cb(s);
> -        s->pdma_cb = NULL;
>      }
>      return val;
>  }
> 

Reviewed-by: Laurent Vivier <laurent@vivier.eu>


  reply	other threads:[~2021-03-02 22:03 UTC|newest]

Thread overview: 135+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-02-09 19:29 [PATCH v2 00/42] esp: consolidate PDMA transfer buffers and other fixes Mark Cave-Ayland
2021-02-09 19:29 ` [PATCH v2 01/42] esp: checkpatch fixes Mark Cave-Ayland
2021-03-01 19:43   ` Laurent Vivier
2021-03-03  8:33     ` Mark Cave-Ayland
2021-02-09 19:29 ` [PATCH v2 02/42] esp: rename existing ESP QOM type to SYSBUS_ESP Mark Cave-Ayland
2021-02-10 22:29   ` Philippe Mathieu-Daudé
2021-03-01 19:52   ` Laurent Vivier
2021-02-09 19:29 ` [PATCH v2 03/42] esp: QOMify the internal ESP device state Mark Cave-Ayland
2021-02-12 18:51   ` Philippe Mathieu-Daudé
2021-02-15 22:29     ` Mark Cave-Ayland
2021-03-01 20:11       ` Laurent Vivier
2021-02-09 19:29 ` [PATCH v2 04/42] esp: add vmstate_esp version to embedded ESPState Mark Cave-Ayland
2021-02-16  7:35   ` Philippe Mathieu-Daudé
2021-03-01 20:21   ` Laurent Vivier
2021-02-09 19:29 ` [PATCH v2 05/42] esp: add trace event when receiving a TI command Mark Cave-Ayland
2021-03-01 20:24   ` Laurent Vivier
2021-02-09 19:29 ` [PATCH v2 06/42] esp: fix esp_reg_read() trace event Mark Cave-Ayland
2021-03-01 20:29   ` Laurent Vivier
2021-02-09 19:29 ` [PATCH v2 07/42] esp: add PDMA trace events Mark Cave-Ayland
2021-03-01 20:32   ` Laurent Vivier
2021-02-09 19:29 ` [PATCH v2 08/42] esp: determine transfer direction directly from SCSI phase Mark Cave-Ayland
2021-02-16  7:36   ` Philippe Mathieu-Daudé
2021-03-01 21:18   ` Laurent Vivier
2021-02-09 19:29 ` [PATCH v2 09/42] esp: introduce esp_get_tc() and esp_set_tc() Mark Cave-Ayland
2021-03-01 21:24   ` Laurent Vivier
2021-03-03  8:35     ` Mark Cave-Ayland
2021-02-09 19:29 ` [PATCH v2 10/42] esp: introduce esp_get_stc() Mark Cave-Ayland
2021-02-10 22:33   ` Philippe Mathieu-Daudé
2021-02-11  7:53     ` Mark Cave-Ayland
2021-02-11 10:07       ` Philippe Mathieu-Daudé
2021-02-15 22:27         ` Mark Cave-Ayland
2021-03-01 21:28   ` Laurent Vivier
2021-02-09 19:29 ` [PATCH v2 11/42] esp: apply transfer length adjustment when STC is zero at TC load time Mark Cave-Ayland
2021-02-16  7:33   ` Philippe Mathieu-Daudé
2021-02-16 21:52     ` Mark Cave-Ayland
2021-03-01 21:35   ` Laurent Vivier
2021-03-03  8:44     ` Mark Cave-Ayland
2021-02-09 19:29 ` [PATCH v2 12/42] esp: remove dma_counter from ESPState Mark Cave-Ayland
2021-02-10 22:37   ` Philippe Mathieu-Daudé
2021-03-01 21:44   ` Laurent Vivier
2021-02-09 19:29 ` [PATCH v2 13/42] esp: remove dma_left " Mark Cave-Ayland
2021-02-23 21:22   ` Philippe Mathieu-Daudé
2021-03-01 21:50   ` Laurent Vivier
2021-02-09 19:29 ` [PATCH v2 14/42] esp: remove minlen restriction in handle_ti Mark Cave-Ayland
2021-02-23 18:24   ` Philippe Mathieu-Daudé
2021-03-01 22:04   ` Laurent Vivier
2021-02-09 19:29 ` [PATCH v2 15/42] esp: introduce esp_pdma_read() and esp_pdma_write() functions Mark Cave-Ayland
2021-02-10 22:51   ` Philippe Mathieu-Daudé
2021-02-11  8:01     ` Mark Cave-Ayland
2021-02-11 10:09       ` Philippe Mathieu-Daudé
2021-03-01 22:06   ` Laurent Vivier
2021-02-09 19:29 ` [PATCH v2 16/42] esp: use pdma_origin directly in esp_pdma_read()/esp_pdma_write() Mark Cave-Ayland
2021-02-23 18:25   ` Philippe Mathieu-Daudé
2021-03-01 22:07   ` Laurent Vivier
2021-02-09 19:29 ` [PATCH v2 17/42] esp: move pdma_len and TC logic into esp_pdma_read()/esp_pdma_write() Mark Cave-Ayland
2021-02-23 21:23   ` Philippe Mathieu-Daudé
2021-03-01 22:09   ` Laurent Vivier
2021-02-09 19:29 ` [PATCH v2 18/42] esp: accumulate SCSI commands for PDMA transfers in cmdbuf instead of pdma_buf Mark Cave-Ayland
2021-02-23 21:25   ` Philippe Mathieu-Daudé
2021-03-02 17:02   ` Laurent Vivier
2021-03-02 17:34     ` Mark Cave-Ayland
2021-03-02 17:59       ` Laurent Vivier
2021-03-02 19:29         ` Mark Cave-Ayland
2021-03-02 21:21           ` Laurent Vivier
2021-03-02 21:22   ` Laurent Vivier
2021-02-09 19:29 ` [PATCH v2 19/42] esp: remove buf parameter from do_cmd() Mark Cave-Ayland
2021-02-23 18:27   ` Philippe Mathieu-Daudé
2021-03-02 17:03   ` Laurent Vivier
2021-02-09 19:29 ` [PATCH v2 20/42] esp: remove the buf and buflen parameters from get_cmd() Mark Cave-Ayland
2021-02-16  7:31   ` Philippe Mathieu-Daudé
2021-03-02 17:03   ` Laurent Vivier
2021-02-09 19:29 ` [PATCH v2 21/42] esp: remove redundant pdma_start from ESPState Mark Cave-Ayland
2021-03-02 21:22   ` Laurent Vivier
2021-02-09 19:29 ` [PATCH v2 22/42] esp: move PDMA length adjustments into esp_pdma_read()/esp_pdma_write() Mark Cave-Ayland
2021-03-02 21:44   ` Laurent Vivier
2021-02-09 19:29 ` [PATCH v2 23/42] esp: use ti_wptr/ti_rptr to manage the current FIFO position for PDMA Mark Cave-Ayland
2021-02-23 21:29   ` Philippe Mathieu-Daudé
2021-03-02 21:47   ` Laurent Vivier
2021-02-09 19:30 ` [PATCH v2 24/42] esp: use in-built TC to determine PDMA transfer length Mark Cave-Ayland
2021-02-23 18:32   ` Philippe Mathieu-Daudé
2021-03-02 21:48   ` Laurent Vivier
2021-02-09 19:30 ` [PATCH v2 25/42] esp: remove CMD pdma_origin Mark Cave-Ayland
2021-02-23 18:34   ` Philippe Mathieu-Daudé
2021-03-02 21:49   ` Laurent Vivier
2021-02-09 19:30 ` [PATCH v2 26/42] esp: rename get_cmd_cb() to esp_select() Mark Cave-Ayland
2021-03-02 21:51   ` Laurent Vivier
2021-02-09 19:30 ` [PATCH v2 27/42] esp: fix PDMA target selection Mark Cave-Ayland
2021-03-02 21:57   ` Laurent Vivier
2021-02-09 19:30 ` [PATCH v2 28/42] esp: use FIFO for PDMA transfers between initiator and device Mark Cave-Ayland
2021-03-02 22:02   ` Laurent Vivier [this message]
2021-02-09 19:30 ` [PATCH v2 29/42] esp: remove pdma_origin from ESPState Mark Cave-Ayland
2021-03-02 22:03   ` Laurent Vivier
2021-02-09 19:30 ` [PATCH v2 30/42] esp: add 4 byte PDMA read and write transfers Mark Cave-Ayland
2021-02-12 18:56   ` Philippe Mathieu-Daudé
2021-02-15 22:35     ` Mark Cave-Ayland
2021-02-16  7:30       ` Philippe Mathieu-Daudé
2021-02-16 21:36         ` Mark Cave-Ayland
2021-02-23  8:24         ` Mark Cave-Ayland
2021-02-23 18:55           ` Philippe Mathieu-Daudé
2021-03-02 22:05   ` Laurent Vivier
2021-02-09 19:30 ` [PATCH v2 31/42] esp: implement FIFO flush command Mark Cave-Ayland
2021-03-03 19:32   ` Laurent Vivier
2021-03-04 18:26     ` Mark Cave-Ayland
2021-02-09 19:30 ` [PATCH v2 32/42] esp: latch individual bits in ESP_RINTR register Mark Cave-Ayland
2021-03-03 19:48   ` Laurent Vivier
2021-02-09 19:30 ` [PATCH v2 33/42] esp: defer command completion interrupt on incoming data transfers Mark Cave-Ayland
2021-02-18 17:25   ` Mark Cave-Ayland
2021-03-03 19:52     ` Laurent Vivier
2021-03-04 18:33       ` Mark Cave-Ayland
2021-02-09 19:30 ` [PATCH v2 34/42] esp: remove old deferred command completion mechanism Mark Cave-Ayland
2021-03-03 19:55   ` Laurent Vivier
2021-02-09 19:30 ` [PATCH v2 35/42] esp: raise interrupt after every non-DMA byte transferred to the FIFO Mark Cave-Ayland
2021-03-03 19:59   ` Laurent Vivier
2021-02-09 19:30 ` [PATCH v2 36/42] esp: add maxlen parameter to get_cmd() Mark Cave-Ayland
2021-02-23 18:43   ` Philippe Mathieu-Daudé
2021-03-03 20:04   ` Laurent Vivier
2021-02-09 19:30 ` [PATCH v2 37/42] esp: transition to message out phase after SATN and stop command Mark Cave-Ayland
2021-03-03 20:06   ` Laurent Vivier
2021-02-09 19:30 ` [PATCH v2 38/42] esp: convert ti_buf from array to Fifo8 Mark Cave-Ayland
2021-02-23 18:49   ` Philippe Mathieu-Daudé
2021-02-25  9:15     ` Mark Cave-Ayland
2021-03-03 20:11   ` Laurent Vivier
2021-02-09 19:30 ` [PATCH v2 39/42] esp: convert cmdbuf " Mark Cave-Ayland
2021-03-03 20:16   ` Laurent Vivier
2021-02-09 19:30 ` [PATCH v2 40/42] esp: add trivial implementation of the ESP_RFLAGS register Mark Cave-Ayland
2021-02-23 18:51   ` Philippe Mathieu-Daudé
2021-03-03 20:19   ` Laurent Vivier
2021-02-09 19:30 ` [PATCH v2 41/42] esp: implement non-DMA transfers in PDMA mode Mark Cave-Ayland
2021-03-03 20:22   ` Laurent Vivier
2021-02-09 19:30 ` [PATCH v2 42/42] esp: add support for unaligned accesses Mark Cave-Ayland
2021-03-03 20:22   ` Laurent Vivier
2021-02-23 21:32 ` [PATCH v2 00/42] esp: consolidate PDMA transfer buffers and other fixes Philippe Mathieu-Daudé
2021-02-25  9:54   ` Mark Cave-Ayland
2021-02-25 10:50     ` Philippe Mathieu-Daudé
2021-02-25 19:17       ` Mark Cave-Ayland

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