From: Samuel Holland <samuel@sholland.org>
To: Arnd Bergmann <arnd@arndb.de>
Cc: Adam Radford <aradford@gmail.com>,
"James E.J. Bottomley" <jejb@linux.ibm.com>,
"Martin K. Petersen" <martin.petersen@oracle.com>,
linux-scsi <linux-scsi@vger.kernel.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] scsi: 3w-9xxx: Fix endianness issues found by sparse
Date: Tue, 28 Jul 2020 23:50:38 -0500 [thread overview]
Message-ID: <351cf74c-1b82-1acf-26c5-682ac4c3fb90@sholland.org> (raw)
In-Reply-To: <CAK8P3a3yj=ySNCn7YtEXxWiRK0FtG+5ftkV+vb3s82yRi7cdLw@mail.gmail.com>
On 7/27/20 2:18 PM, Arnd Bergmann wrote:
> On Sun, Jul 26, 2020 at 9:15 PM Samuel Holland <samuel@sholland.org> wrote:
>>
>> The main issue observed was at the call to scsi_set_resid, where the
>> byteswapped parameter would eventually trigger the alignment check at
>> drivers/scsi/sd.c:2009. At that point, the kernel would continuously
>> complain about an "Unaligned partial completion", and no further I/O
>> could occur.
>>
>> This gets the controller working on big endian powerpc64.
>>
>> Signed-off-by: Samuel Holland <samuel@sholland.org>
>> ---
>> drivers/scsi/3w-9xxx.c | 35 +++++++++++++++++------------------
>> drivers/scsi/3w-9xxx.h | 6 +++++-
>> 2 files changed, 22 insertions(+), 19 deletions(-)
>>
>> diff --git a/drivers/scsi/3w-9xxx.c b/drivers/scsi/3w-9xxx.c
>> index 3337b1e80412..95e25fda1f90 100644
>> --- a/drivers/scsi/3w-9xxx.c
>> +++ b/drivers/scsi/3w-9xxx.c
>> @@ -303,10 +303,10 @@ static int twa_aen_drain_queue(TW_Device_Extension *tw_dev, int no_check_reset)
>>
>> /* Initialize sglist */
>> memset(&sglist, 0, sizeof(TW_SG_Entry));
>> - sglist[0].length = TW_SECTOR_SIZE;
>> - sglist[0].address = tw_dev->generic_buffer_phys[request_id];
>> + sglist[0].length = cpu_to_le32(TW_SECTOR_SIZE);
>> + sglist[0].address = TW_CPU_TO_SGL(tw_dev->generic_buffer_phys[request_id]);
>
> This looks like it would add a sparse warning, not fix one, unless you also
> change the types of the target structure.
Yes, I meant to change the structure types as well. All of the command
structures sent to the card are little-endian. I pulled this bugfix patch out of
a series of unrelated changes, and I missed the header changes. I'll send a v2.
>> @@ -501,7 +501,7 @@ static void twa_aen_sync_time(TW_Device_Extension *tw_dev, int request_id)
>> Sunday 12:00AM */
>> local_time = (ktime_get_real_seconds() - (sys_tz.tz_minuteswest * 60));
>> div_u64_rem(local_time - (3 * 86400), 604800, &schedulertime);
>> - schedulertime = cpu_to_le32(schedulertime % 604800);
>> + cpu_to_le32p(&schedulertime);
>>
>> memcpy(param->data, &schedulertime, sizeof(u32));
>
> You dropped the '%' operation, and the result of the byteswap?
schedulertime is the remainder from the previous line, so it is <604800 already.
You're right about that being the wrong function -- I meant to use cpu_to_le32s
to swap it in place, to avoid needing a second variable.
>> @@ -1004,7 +1004,7 @@ static int twa_fill_sense(TW_Device_Extension *tw_dev, int request_id, int copy_
>> full_command_packet->header.status_block.error,
>> error_str[0] == '\0' ?
>> twa_string_lookup(twa_error_table,
>> - full_command_packet->header.status_block.error) : error_str,
>> + le16_to_cpu(full_command_packet->header.status_block.error)) : error_str,
>> full_command_packet->header.err_specific_desc);
>> else
>
> This looks correct, but the error value has already been copied into the local
> 'error' variable, which you could use for simplification. As 'status_block' is
> defined as a native_endian structure, this also introduced a sparse warning.
I'll use 'error' in v2, thanks for the hint.
>> @@ -1012,7 +1012,7 @@ static int twa_fill_sense(TW_Device_Extension *tw_dev, int request_id, int copy_
>> full_command_packet->header.status_block.error,
>> error_str[0] == '\0' ?
>> twa_string_lookup(twa_error_table,
>> - full_command_packet->header.status_block.error) : error_str,
>> + le16_to_cpu(full_command_packet->header.status_block.error)) : error_str,
>
> Same here
>
> Arnd
>
Cheers,
Samuel
prev parent reply other threads:[~2020-07-29 4:50 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-26 19:14 [PATCH] scsi: 3w-9xxx: Fix endianness issues found by sparse Samuel Holland
2020-07-27 19:18 ` Arnd Bergmann
2020-07-29 4:50 ` Samuel Holland [this message]
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