From: "Philippe Mathieu-Daudé" <f4bug@amsat.org>
To: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>,
qemu-devel@nongnu.org, alxndr@bu.edu, laurent@vivier.eu,
pbonzini@redhat.com
Subject: Re: [PATCH v3 02/11] esp: rework write_response() to avoid using the FIFO for DMA transactions
Date: Thu, 1 Apr 2021 10:26:29 +0200 [thread overview]
Message-ID: <bc943319-b721-373f-8def-99ff0da0d0b5@amsat.org> (raw)
In-Reply-To: <20210401074933.9923-3-mark.cave-ayland@ilande.co.uk>
On 4/1/21 9:49 AM, Mark Cave-Ayland wrote:
> The code for write_response() has always used the FIFO to store the data for
> the status/message in phases, even for DMA transactions. Switch to using a
> separate buffer that can be used directly for DMA transactions and restrict
> the FIFO use to the non-DMA case.
>
> Signed-off-by: Mark Cave-Ayland <mark.cave-ayland@ilande.co.uk>
> ---
> hw/scsi/esp.c | 13 ++++++-------
> 1 file changed, 6 insertions(+), 7 deletions(-)
>
> diff --git a/hw/scsi/esp.c b/hw/scsi/esp.c
> index bafea0d4e6..26fe1dcb9d 100644
> --- a/hw/scsi/esp.c
> +++ b/hw/scsi/esp.c
> @@ -445,18 +445,16 @@ static void write_response_pdma_cb(ESPState *s)
>
> static void write_response(ESPState *s)
> {
> - uint32_t n;
> + uint8_t buf[2];
>
> trace_esp_write_response(s->status);
>
> - fifo8_reset(&s->fifo);
> - esp_fifo_push(s, s->status);
> - esp_fifo_push(s, 0);
> + buf[0] = s->status;
> + buf[1] = 0;
Slightly simplified:
const uint8_t buf[2] = { s->status, 0 };
> if (s->dma) {
uint32_t n;
> if (s->dma_memory_write) {
> - s->dma_memory_write(s->dma_opaque,
> - (uint8_t *)fifo8_pop_buf(&s->fifo, 2, &n), 2);
> + s->dma_memory_write(s->dma_opaque, buf, 2);
> s->rregs[ESP_RSTAT] = STAT_TC | STAT_ST;
> s->rregs[ESP_RINTR] |= INTR_BS | INTR_FC;
> s->rregs[ESP_RSEQ] = SEQ_CD;
> @@ -466,7 +464,8 @@ static void write_response(ESPState *s)
> return;
> }
> } else {
> - s->ti_size = 2;
> + fifo8_reset(&s->fifo);
> + fifo8_push_all(&s->fifo, buf, 2);
> s->rregs[ESP_RFLAGS] = 2;
> }
> esp_raise_irq(s);
>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
next prev parent reply other threads:[~2021-04-01 8:29 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-01 7:49 [PATCH v3 00/11] esp: fix asserts/segfaults discovered by fuzzer Mark Cave-Ayland
2021-04-01 7:49 ` [PATCH v3 01/11] esp: always check current_req is not NULL before use in DMA callbacks Mark Cave-Ayland
2021-04-01 7:49 ` [PATCH v3 02/11] esp: rework write_response() to avoid using the FIFO for DMA transactions Mark Cave-Ayland
2021-04-01 8:26 ` Philippe Mathieu-Daudé [this message]
2021-04-01 7:49 ` [PATCH v3 03/11] esp: consolidate esp_cmdfifo_push() into esp_fifo_push() Mark Cave-Ayland
2021-04-01 8:15 ` Philippe Mathieu-Daudé
2021-04-01 8:50 ` Mark Cave-Ayland
2021-04-01 9:16 ` Philippe Mathieu-Daudé
2021-04-01 7:49 ` [PATCH v3 04/11] esp: consolidate esp_cmdfifo_pop() into esp_fifo_pop() Mark Cave-Ayland
2021-04-01 8:15 ` Philippe Mathieu-Daudé
2021-04-01 7:49 ` [PATCH v3 05/11] esp: introduce esp_fifo_pop_buf() and use it instead of fifo8_pop_buf() Mark Cave-Ayland
2021-04-01 9:34 ` Philippe Mathieu-Daudé
2021-04-01 10:51 ` Mark Cave-Ayland
2021-04-01 18:05 ` Philippe Mathieu-Daudé
2021-04-01 7:49 ` [PATCH v3 06/11] esp: ensure cmdfifo is not empty and current_dev is non-NULL Mark Cave-Ayland
2021-04-01 8:17 ` Philippe Mathieu-Daudé
2021-04-01 7:49 ` [PATCH v3 07/11] esp: don't underflow cmdfifo in do_cmd() Mark Cave-Ayland
2021-04-01 8:19 ` Philippe Mathieu-Daudé
2021-04-01 8:51 ` Mark Cave-Ayland
2021-04-01 7:49 ` [PATCH v3 08/11] esp: don't overflow cmdfifo in get_cmd() Mark Cave-Ayland
2021-04-01 8:19 ` Philippe Mathieu-Daudé
2021-04-01 8:56 ` Mark Cave-Ayland
2021-04-01 7:49 ` [PATCH v3 09/11] esp: don't overflow cmdfifo if TC is larger than the cmdfifo size Mark Cave-Ayland
2021-04-01 7:49 ` [PATCH v3 10/11] esp: don't reset async_len directly in esp_select() if cancelling request Mark Cave-Ayland
2021-04-01 7:49 ` [PATCH v3 11/11] tests/qtest: add tests for am53c974 device Mark Cave-Ayland
2021-04-01 16:55 ` Alexander Bulekov
2021-04-02 7:29 ` Mark Cave-Ayland
2021-04-01 17:00 ` [PATCH v3 00/11] esp: fix asserts/segfaults discovered by fuzzer Alexander Bulekov
2021-04-02 7:35 ` Mark Cave-Ayland
2021-04-02 16:20 ` [PATCH] tests/qtest: add one more test for the am53c974 Alexander Bulekov
2021-04-03 14:38 ` Mark Cave-Ayland
2021-04-07 12:08 ` Mark Cave-Ayland
2021-04-07 13:04 ` Mark Cave-Ayland
2021-04-07 14:49 ` Alexander Bulekov
2021-04-07 15:11 ` Mark Cave-Ayland
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=bc943319-b721-373f-8def-99ff0da0d0b5@amsat.org \
--to=f4bug@amsat.org \
--cc=alxndr@bu.edu \
--cc=laurent@vivier.eu \
--cc=mark.cave-ayland@ilande.co.uk \
--cc=pbonzini@redhat.com \
--cc=qemu-devel@nongnu.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).