From: Keith Busch <kbusch@kernel.org>
To: "Philippe Mathieu-Daudé" <philmd@redhat.com>
Cc: Fam Zheng <fam@euphon.net>, Kevin Wolf <kwolf@redhat.com>,
qemu-block@nongnu.org, qemu-devel@nongnu.org,
Max Reitz <mreitz@redhat.com>, Eric Auger <eric.auger@redhat.com>,
Stefan Hajnoczi <stefanha@redhat.com>,
Klaus Jensen <its@irrelevant.dk>
Subject: Re: [PATCH 08/25] block/nvme: Simplify device reset
Date: Tue, 27 Oct 2020 09:55:34 -0700 [thread overview]
Message-ID: <20201027165534.GA1942297@dhcp-10-100-145-180.wdc.com> (raw)
In-Reply-To: <1bb84312-1c78-7e1a-058b-4ff6330076b1@redhat.com>
On Tue, Oct 27, 2020 at 04:53:31PM +0100, Philippe Mathieu-Daudé wrote:
> On 10/27/20 3:58 PM, Keith Busch wrote:
> > On Tue, Oct 27, 2020 at 02:55:30PM +0100, Philippe Mathieu-Daudé wrote:
> >> Avoid multiple endianess conversion by using device endianess.
> >>
> >> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> >> ---
> >> block/nvme.c | 2 +-
> >> 1 file changed, 1 insertion(+), 1 deletion(-)
> >>
> >> diff --git a/block/nvme.c b/block/nvme.c
> >> index e95d59d3126..be14350f959 100644
> >> --- a/block/nvme.c
> >> +++ b/block/nvme.c
> >> @@ -755,7 +755,7 @@ static int nvme_init(BlockDriverState *bs, const char *device, int namespace,
> >> timeout_ms = MIN(500 * NVME_CAP_TO(cap), 30000);
> >>
> >> /* Reset device to get a clean state. */
> >> - regs->cc = cpu_to_le32(le32_to_cpu(regs->cc) & 0xFE);
> >> + regs->cc &= const_le32(0xFE);
> >
> > This doesn't look right. The 'regs' is an MMIO address, correct? Memory
> > mappings use the CPU native access.
>
> cc is little-endian uint32_t.
Well, yes and no. PCI is defined as a little endian transport, so all
CPUs have to automatically convert from their native format when
accessing memory mapped addresses over that transport, so you always use
the arch native format from the host software.
This isn't just for CC. This includes all memory mapped registers, so
this driver's CSTS, AQA, doorbells, etc... shouldn't have any endian
swapping.
See also: every other nvme driver. :)
next prev parent reply other threads:[~2020-10-27 16:56 UTC|newest]
Thread overview: 83+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-10-27 13:55 [PATCH 00/25] block/nvme: Fix Aarch64 host Philippe Mathieu-Daudé
2020-10-27 13:55 ` [PATCH 01/25] MAINTAINERS: Cover 'block/nvme.h' file Philippe Mathieu-Daudé
2020-10-28 15:47 ` Stefan Hajnoczi
2020-10-27 13:55 ` [PATCH 02/25] block/nvme: Use hex format to display offset in trace events Philippe Mathieu-Daudé
2020-10-28 10:21 ` Auger Eric
2020-10-28 15:47 ` Stefan Hajnoczi
2020-10-27 13:55 ` [PATCH 03/25] block/nvme: Report warning with warn_report() Philippe Mathieu-Daudé
2020-10-27 14:45 ` Keith Busch
2020-10-27 15:33 ` Philippe Mathieu-Daudé
2020-10-27 15:54 ` Philippe Mathieu-Daudé
2020-10-28 10:22 ` Auger Eric
2020-10-28 15:47 ` Stefan Hajnoczi
2020-10-27 13:55 ` [PATCH 04/25] block/nvme: Trace controller capabilities Philippe Mathieu-Daudé
2020-10-28 10:20 ` Auger Eric
2020-10-28 10:25 ` Philippe Mathieu-Daudé
2020-10-28 10:36 ` Auger Eric
2020-10-27 13:55 ` [PATCH 05/25] block/nvme: Trace nvme_poll_queue() per queue Philippe Mathieu-Daudé
2020-10-28 10:31 ` Auger Eric
2020-10-28 15:48 ` Stefan Hajnoczi
2020-10-27 13:55 ` [PATCH 06/25] block/nvme: Improve nvme_free_req_queue_wait() trace information Philippe Mathieu-Daudé
2020-10-28 10:32 ` Auger Eric
2020-10-28 15:48 ` Stefan Hajnoczi
2020-10-27 13:55 ` [PATCH 07/25] block/nvme: Trace queue pair creation/deletion Philippe Mathieu-Daudé
2020-10-28 10:28 ` Auger Eric
2020-10-28 15:48 ` Stefan Hajnoczi
2020-10-27 13:55 ` [PATCH 08/25] block/nvme: Simplify device reset Philippe Mathieu-Daudé
2020-10-27 14:54 ` Keith Busch
2020-10-27 14:58 ` Keith Busch
2020-10-27 15:53 ` Philippe Mathieu-Daudé
2020-10-27 16:55 ` Keith Busch [this message]
2020-10-28 15:02 ` Stefan Hajnoczi
2020-10-28 15:10 ` Keith Busch
2020-10-27 13:55 ` [PATCH 09/25] block/nvme: Move definitions before structure declarations Philippe Mathieu-Daudé
2020-10-28 10:44 ` Auger Eric
2020-10-28 15:49 ` Stefan Hajnoczi
2020-10-27 13:55 ` [PATCH 10/25] block/nvme: Use unsigned integer for queue counter/size Philippe Mathieu-Daudé
2020-10-28 10:48 ` Auger Eric
2020-10-28 15:49 ` Stefan Hajnoczi
2020-10-27 13:55 ` [PATCH 11/25] block/nvme: Make nvme_identify() return boolean indicating error Philippe Mathieu-Daudé
2020-10-28 11:03 ` Auger Eric
2020-10-28 15:07 ` Stefan Hajnoczi
2020-10-27 13:55 ` [PATCH 12/25] block/nvme: Make nvme_init_queue() " Philippe Mathieu-Daudé
2020-10-28 11:10 ` Auger Eric
2020-10-28 15:11 ` Stefan Hajnoczi
2020-10-27 13:55 ` [PATCH 13/25] block/nvme: Introduce Completion Queue definitions Philippe Mathieu-Daudé
2020-10-28 11:18 ` Auger Eric
2020-10-28 15:10 ` Stefan Hajnoczi
2020-10-28 15:16 ` Stefan Hajnoczi
2020-10-28 18:24 ` Philippe Mathieu-Daudé
2020-10-29 9:02 ` Philippe Mathieu-Daudé
2020-10-30 11:46 ` Stefan Hajnoczi
2020-10-30 14:51 ` Philippe Mathieu-Daudé
2020-10-27 13:55 ` [PATCH 14/25] block/nvme: Use definitions instead of magic values in add_io_queue() Philippe Mathieu-Daudé
2020-10-28 14:17 ` Auger Eric
2020-10-28 15:16 ` Stefan Hajnoczi
2020-10-27 13:55 ` [PATCH 15/25] block/nvme: Correctly initialize Admin Queue Attributes Philippe Mathieu-Daudé
2020-10-28 14:21 ` Auger Eric
2020-10-28 15:17 ` Stefan Hajnoczi
2020-10-27 13:55 ` [PATCH 16/25] block/nvme: Simplify ADMIN queue access Philippe Mathieu-Daudé
2020-10-28 14:25 ` Auger Eric
2020-10-28 15:19 ` Stefan Hajnoczi
2020-10-27 13:55 ` [PATCH 17/25] block/nvme: Simplify nvme_cmd_sync() Philippe Mathieu-Daudé
2020-10-28 14:27 ` Auger Eric
2020-10-28 15:21 ` Stefan Hajnoczi
2020-10-29 7:35 ` Philippe Mathieu-Daudé
2020-10-27 13:55 ` [PATCH 18/25] block/nvme: Pass AioContext argument to nvme_add_io_queue() Philippe Mathieu-Daudé
2020-10-28 14:30 ` Auger Eric
2020-10-28 15:30 ` Stefan Hajnoczi
2020-10-27 13:55 ` [PATCH 19/25] block/nvme: Set request_alignment at initialization Philippe Mathieu-Daudé
2020-10-27 13:55 ` [PATCH 20/25] block/nvme: Correct minimum device page size Philippe Mathieu-Daudé
2020-10-27 13:55 ` [PATCH 21/25] block/nvme: Change size and alignment of IDENTIFY response buffer Philippe Mathieu-Daudé
2020-10-28 15:35 ` Stefan Hajnoczi
2020-10-27 13:55 ` [PATCH 22/25] block/nvme: Change size and alignment of queue Philippe Mathieu-Daudé
2020-10-28 15:37 ` Stefan Hajnoczi
2020-10-27 13:55 ` [PATCH 23/25] block/nvme: Change size and alignment of prp_list_pages Philippe Mathieu-Daudé
2020-10-28 15:38 ` Stefan Hajnoczi
2020-10-27 13:55 ` [PATCH 24/25] block/nvme: Align iov's va and size on host page size Philippe Mathieu-Daudé
2020-10-28 15:41 ` Stefan Hajnoczi
2020-10-27 13:55 ` [RFC PATCH 25/25] block/nvme: Fix use of write-only doorbells page on Aarch64 arch Philippe Mathieu-Daudé
2020-10-28 15:47 ` Stefan Hajnoczi
2020-10-28 16:12 ` Auger Eric
2020-10-28 18:10 ` [PATCH 00/25] block/nvme: Fix Aarch64 host Auger Eric
2020-10-29 9:08 ` Philippe Mathieu-Daudé
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