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From:   Jinpu Wang <jinpu.wang@ionos.com>
Date:   Fri, 30 Sep 2022 11:15:54 +0200
Message-ID: <CAMGffEmK6j0EzDfa4QNQOSVYkCx-m8Q_eHOLFOesu8VNhtiRPQ@mail.gmail.com>
Subject: Re: [PATCH v2 3/6] scsi: pm8001: Remove pm8001_tag_init()
To:     John Garry <john.garry@huawei.com>
Cc:     jejb@linux.ibm.com, martin.petersen@oracle.com,
        jinpu.wang@ionos.com, damien.lemoal@wdc.com, hare@suse.de,
        linux-scsi@vger.kernel.org, linux-kernel@vger.kernel.org,
        linuxarm@huawei.com, ipylypiv@google.com, changyuanl@google.com,
        hch@lst.de, yanaijie@huawei.com
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On Fri, Sep 30, 2022 at 11:03 AM John Garry <john.garry@huawei.com> wrote:
>
> From: Igor Pylypiv <ipylypiv@google.com>
>
> In commit 5a141315ed7c ("scsi: pm80xx: Increase the number of outstanding
> I/O supported to 1024") the pm8001_ha->tags allocation was moved into
> pm8001_init_ccb_tag(). This changed the execution order of allocation.
> pm8001_tag_init() used to be called after the pm8001_ha->tags allocation
> and now it is called before the allocation.
>
> Before:
>
> pm8001_pci_probe()
> `--> pm8001_pci_alloc()
>      `--> pm8001_alloc()
>           `--> pm8001_ha->tags = kzalloc(...)
>           `--> pm8001_tag_init(pm8001_ha); // OK: tags are allocated
>
> After:
>
> pm8001_pci_probe()
> `--> pm8001_pci_alloc()
> |    `--> pm8001_alloc()
> |         `--> pm8001_tag_init(pm8001_ha); // NOK: tags are not allocated
> |
> `--> pm8001_init_ccb_tag()
>      `-->  pm8001_ha->tags = kzalloc(...) // today it is bitmap_zalloc()
>
> Since pm8001_ha->tags_num is zero when pm8001_tag_init() is called it does
> nothing. Tags memory is allocated with bitmap_zalloc() so there is no need
> to manually clear each bit with pm8001_tag_free().
>
> Reviewed-by: Changyuan Lyu <changyuanl@google.com>
> Signed-off-by: Igor Pylypiv <ipylypiv@google.com>
> Signed-off-by: John Garry <john.garry@huawei.com>
> Reviewed-by: Damien Le Moal <damien.lemoal@opensource.wdc.com>
Reviewed-by: Jack Wang <jinpu.wang@ionos.com>
> ---
>  drivers/scsi/pm8001/pm8001_init.c | 2 --
>  drivers/scsi/pm8001/pm8001_sas.c  | 7 -------
>  drivers/scsi/pm8001/pm8001_sas.h  | 1 -
>  3 files changed, 10 deletions(-)
>
> diff --git a/drivers/scsi/pm8001/pm8001_init.c b/drivers/scsi/pm8001/pm8001_init.c
> index a0028e130a7e..0edc9857a8bd 100644
> --- a/drivers/scsi/pm8001/pm8001_init.c
> +++ b/drivers/scsi/pm8001/pm8001_init.c
> @@ -436,8 +436,6 @@ static int pm8001_alloc(struct pm8001_hba_info *pm8001_ha,
>                 atomic_set(&pm8001_ha->devices[i].running_req, 0);
>         }
>         pm8001_ha->flags = PM8001F_INIT_TIME;
> -       /* Initialize tags */
> -       pm8001_tag_init(pm8001_ha);
>         return 0;
>
>  err_out_nodev:
> diff --git a/drivers/scsi/pm8001/pm8001_sas.c b/drivers/scsi/pm8001/pm8001_sas.c
> index d5ec29f69be3..066dfa9f4683 100644
> --- a/drivers/scsi/pm8001/pm8001_sas.c
> +++ b/drivers/scsi/pm8001/pm8001_sas.c
> @@ -96,13 +96,6 @@ int pm8001_tag_alloc(struct pm8001_hba_info *pm8001_ha, u32 *tag_out)
>         return 0;
>  }
>
> -void pm8001_tag_init(struct pm8001_hba_info *pm8001_ha)
> -{
> -       int i;
> -       for (i = 0; i < pm8001_ha->tags_num; ++i)
> -               pm8001_tag_free(pm8001_ha, i);
> -}
> -
>  /**
>   * pm8001_mem_alloc - allocate memory for pm8001.
>   * @pdev: pci device.
> diff --git a/drivers/scsi/pm8001/pm8001_sas.h b/drivers/scsi/pm8001/pm8001_sas.h
> index 8ab0654327f9..9acaadf02150 100644
> --- a/drivers/scsi/pm8001/pm8001_sas.h
> +++ b/drivers/scsi/pm8001/pm8001_sas.h
> @@ -632,7 +632,6 @@ extern struct workqueue_struct *pm8001_wq;
>
>  /******************** function prototype *********************/
>  int pm8001_tag_alloc(struct pm8001_hba_info *pm8001_ha, u32 *tag_out);
> -void pm8001_tag_init(struct pm8001_hba_info *pm8001_ha);
>  u32 pm8001_get_ncq_tag(struct sas_task *task, u32 *tag);
>  void pm8001_ccb_task_free(struct pm8001_hba_info *pm8001_ha,
>                           struct pm8001_ccb_info *ccb);
> --
> 2.35.3
>