From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 47D221FF610; Wed, 13 Nov 2024 13:54:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731506068; cv=none; b=AIkRlxnhgsHeG7b122wXzHZvmVjmKtYan4J+VwRTY7ivVCUUamU2TqlWTogGbqNzCCDDhgOxVjRI/y9mNr0diXYfZGWmgs+RYk54ysF+tvl6pwYntNm6edLXwBqEbkPoUr5PH1OcKt6aaESF0w4CkUpN2f0VDpaERAaupYy4CGw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731506068; c=relaxed/simple; bh=3B/JCdh4iX3172gc1ZApZTKHI0NdrBjDEoJdyOuJKVg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=PGLn0AXO4JoHZL5f/WSTWYpmMHplXfI3BX/VG6MAqWblHDM4R98ulxuMhGUyaFWOS0xAsDL1qvpewoP6wo4w14zWoh8g0tqdxgYyJZGIacnMCUVXypxdtuD1XclJd2l81qmksgDIE9/NMkAS+gX9enhqr7efXX7aKviR0L9bHS8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=GTnOZNgK; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="GTnOZNgK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2D5DDC4CEC3; Wed, 13 Nov 2024 13:54:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1731506066; bh=3B/JCdh4iX3172gc1ZApZTKHI0NdrBjDEoJdyOuJKVg=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=GTnOZNgKse/6G382NfGAX65+kCSYHKUzAxz0956dUBqo8v40DlGKgyR586nlN3IJw ofuXXUrwDQCp6V46XTbPsSv3ex0dB+Jo9L1ITVX0d2b4pwAhhbQ3/s/gAyosdw64y+ sgZN9gs5iFNYdC0rf0Gt40QH65rx3mjQHbcDeOu0= Date: Wed, 13 Nov 2024 14:54:23 +0100 From: Greg Kroah-Hartman To: John Garry Cc: Daniel Wagner , Daniel Wagner , Jens Axboe , Bjorn Helgaas , "Michael S. Tsirkin" , Jason Wang , Xuan Zhuo , Eugenio =?iso-8859-1?Q?P=E9rez?= , "Martin K. Petersen" , Keith Busch , Christoph Hellwig , Sagi Grimberg , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, virtualization@lists.linux.dev, linux-scsi@vger.kernel.org, megaraidlinux.pdl@broadcom.com, mpi3mr-linuxdrv.pdl@broadcom.com, MPT-FusionLinux.pdl@broadcom.com, storagedev@microchip.com, linux-nvme@lists.infradead.org Subject: Re: [PATCH v3 1/8] driver core: bus: add irq_get_affinity callback to bus_type Message-ID: <2024111323-darkening-sappy-23fa@gregkh> References: <20241112-refactor-blk-affinity-helpers-v3-0-573bfca0cbd8@kernel.org> <20241112-refactor-blk-affinity-helpers-v3-1-573bfca0cbd8@kernel.org> <76da6c05-4f28-41cc-a48e-da2ae16c64c4@oracle.com> <2d85aa5e-037a-45c3-9f2d-e46b2159b697@flourine.local> Precedence: bulk X-Mailing-List: linux-scsi@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: On Wed, Nov 13, 2024 at 01:44:02PM +0000, John Garry wrote: > On 13/11/2024 12:36, Daniel Wagner wrote: > > > > @@ -48,6 +48,7 @@ struct fwnode_handle; > > > > * will never get called until they do. > > > > * @remove: Called when a device removed from this bus. > > > My impression is that this would be better suited to "struct device_driver", > > > but I assume that there is a good reason to add to "struct bus_type". > > I think the main reason to put it here is that most of the drivers are > > happy with the getter on bus level and don't need special treatment. We > > don't have to touch all the drivers to hookup a common getter, nor do we > > have to install a default handler when the driver doesn't specify one. > > Having the callback in struct bus_driver avoids this. Though Christoph > > suggested it, so I can only guess. > > > > But you bring up a good point, if we had also an irq_get_affinity > > callback in struct device_driver it would be possible for the > > hisi_sas v2 driver to provide a getter and blk_mq_hctx_map_queues could > > do: > > > > for (queue = 0; queue < qmap->nr_queues; queue++) { > > if (dev->driver->irq_get_affinity) > > mask = dev->driver->irq_get_affinity; > > else if (dev->bus->irq_get_affinity) > > mask = dev->bus->irq_get_affinity(dev, queue + offset); > > if (!mask) > > goto fallback; > > > > for_each_cpu(cpu, mask) > > qmap->mq_map[cpu] = qmap->queue_offset + queue; > > } > > > > and with this in place the open coded version in hisi_sas v2 can also be > > replaced. > > Yeah, I think that it could be plugged in like: > > diff --git a/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c > b/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c > index 342d75f12051..5172af77a3f0 100644 > --- a/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c > +++ b/drivers/scsi/hisi_sas/hisi_sas_v2_hw.c > @@ -3636,6 +3636,7 @@ static struct platform_driver hisi_sas_v2_driver = { > .name = DRV_NAME, > .of_match_table = sas_v2_of_match, > .acpi_match_table = ACPI_PTR(sas_v2_acpi_match), > + .irq_get_affinity_mask = hisi_sas_v2_get_affinity_mask, > }, > }; > > > > If no one objects, I go ahead and add the callback to struct > > device_driver. > > I'd wait for Christoph and Greg to both agree. I was just wondering why we > use bus_type. bus types are good to set it at a bus level so you don't have to explicitly set it at each-and-every-driver. Depends on what you want this to be, if it is a "all drivers of this bus type will have the same callback" then put it on the bus. otherwise if you are going to mix/match on a same bus, then put it in the driver structure. hope this helps, greg k-h