linux-kernel - RE: [Bugfix 3/3] eata: Enhance eata driver to support PCI device hot-removal

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 14 Sep 2015 04:31:06 -0400
From:	"Ballabio, Dario" <dario.ballabio@....com>
To:	Hannes Reinecke <hare@...e.de>,
	Jiang Liu <jiang.liu@...ux.intel.com>,
	Thomas Gleixner <tglx@...utronix.de>,
	Bjorn Helgaas <bhelgaas@...gle.com>,
	Arthur Marsh <arthur.marsh@...ernode.on.net>,
	"James E.J. Bottomley" <JBottomley@...n.com>
CC:	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	"linux-pci@...r.kernel.org" <linux-pci@...r.kernel.org>,
	"linux-scsi@...r.kernel.org" <linux-scsi@...r.kernel.org>,
	"x86@...nel.org" <x86@...nel.org>
Subject: RE: [Bugfix 3/3] eata: Enhance eata driver to support PCI device
 hot-removal

Agreed, It does not make sense to have  this driver converted to a hot plug api.

Cheers,



***************************************
Ph.D. Dario Ballabio
Principal Field Support Specialist, EMC EMEA 
Mobile phone: +393487978851



-----Original Message-----
From: Hannes Reinecke [mailto:hare@...e.de] 
Sent: Monday, September 14, 2015 10:21 AM
To: Jiang Liu; Thomas Gleixner; Bjorn Helgaas; Arthur Marsh; Ballabio, Dario; James E.J. Bottomley
Cc: linux-kernel@...r.kernel.org; linux-pci@...r.kernel.org; linux-scsi@...r.kernel.org; x86@...nel.org
Subject: Re: [Bugfix 3/3] eata: Enhance eata driver to support PCI device hot-removal

On 09/14/2015 05:08 AM, Jiang Liu wrote:
> Due to having no hardware for testing, this is just a sample code to 
> support PCI device hot-removal. It just passing compilation, no any 
> tests.
> 
> Signed-off-by: Jiang Liu <jiang.liu@...ux.intel.com>
> ---
>  drivers/scsi/eata.c |   26 ++++++++++++++++++++++++++
>  1 file changed, 26 insertions(+)
> 
> diff --git a/drivers/scsi/eata.c b/drivers/scsi/eata.c index 
> b92e6856f909..f3bd7cbf260e 100644
> --- a/drivers/scsi/eata.c
> +++ b/drivers/scsi/eata.c
> @@ -1474,6 +1474,21 @@ static unsigned int port_probe(unsigned long 
> port_base,  #ifdef CONFIG_PCI  static int eata2x_pci_device_count;
>  
> +/* TODO: need help here to shutdown the scsi host and release 
> +resources */ static void port_remove(unsigned int id, resource_size_t port_base,
> +			struct pci_dev *pdev)
> +{
> +	struct Scsi_Host *shost = sh[id];
> +
> +	/* TODO: stop scsi device */
> +	scsi_unregister(shost);
> +	/* TODO: clean up resources allocated by port_detect() */
> +	clear_bit(id, eata_board_bitmap);
> +	free_irq(shost->irq, &sha[id]);
> +	release_region(port_base, REGION_SIZE);
> +	ida_simple_remove(&eata_ida, id);
> +}
> +
>  static int eata2x_pci_probe(struct pci_dev *dev, const struct 
> pci_device_id *id)  {
>  	int i, ret = -ENXIO;
> @@ -1521,6 +1536,16 @@ out_error:
>  	return ret;
>  }
>  
> +static void eata2x_pci_remove(struct pci_dev *pdev) {
> +	int id = (int)(long)dev_get_drvdata(&pdev->dev);
> +	resource_size_t port_base;
> +
> +	port_base = pci_resource_start(pdev, 0) + PCI_BASE_ADDRESS_0;
> +	port_remove(id, port_base, pdev);
> +	pci_disable_device(pdev);
> +}
> +
>  static struct pci_device_id eata2x_tbl[] = {
>  	{ PCI_DEVICE_CLASS(PCI_CLASS_STORAGE_SCSI << 8, PCI_ANY_ID) },
>  	{ },
> @@ -1531,6 +1556,7 @@ static struct pci_driver eata2x_pci_driver = {
>  	.name		= "eata",
>  	.id_table	= eata2x_tbl,
>  	.probe		= eata2x_pci_probe,
> +	.remove		= eata2x_pci_remove,
>  };
>  
>  static int eata2x_probe_pci_devices(struct scsi_host_template *tpnt)
> 
Welll ... if you don't have hardware (and I strongly hope you refer to 'hardware able to do hotplugging', not 'hardware for the eata driver'
...) why add the code at all?
Chances are no-one will ever need eata PCI hotplug; SCSI parallel typically isn't very good at hotplugging, so throwing in PCI hotplug will only confuse matters more.
Plus due to the sheer mechanics involved here I find it very unlikely anyone will be using it in real life.

Cheers,

Hannes
-- 
Dr. Hannes Reinecke		      zSeries & Storage
hare@...e.de			      +49 911 74053 688
SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg)
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/