finding pci_dev from scsi_device

finding pci_dev from scsi_device

[Herbert Rosmanith]

good day,

Could someone please tell me how to find the corresponding
"struct pci_dev *" from a given "struct scsi_device *"?

I've been searching through structures/header files now for
quite some time, but cannot find anything.

thanks in advance,
h.rosmanith

Re: finding pci_dev from scsi_device

[Arjan van de Ven]

On Mon, 2006-06-26 at 15:55 +0200, Herbert Rosmanith wrote:
> good day,
> 
> Could someone please tell me how to find the corresponding
> "struct pci_dev *" from a given "struct scsi_device *"?
> 
> I've been searching through structures/header files now for
> quite some time, but cannot find anything.

looking at my isa bus scsi controller... I'd say that that is a really
hard question that doesn't even always have an answer ;)

can you share with us what you want to do with this?

Greetings,
   Arjan van de Ven

Re: finding pci_dev from scsi_device

[Herbert Rosmanith]

> > Could someone please tell me how to find the corresponding
> > "struct pci_dev *" from a given "struct scsi_device *"?
> > 
> > I've been searching through structures/header files now for
> > quite some time, but cannot find anything.
> 
> looking at my isa bus scsi controller... I'd say that that is a really
> hard question that doesn't even always have an answer ;)

umh, yes, but in this case, I'm sure I always have a pci_dev.
 
> can you share with us what you want to do with this?

I need the pci_dev to reconfigure ahci-controllers so that they look like
having been initialised by BIOS at reboot time.

kind regards,
h.rosmanith 

Re: finding pci_dev from scsi_device

[Herbert Rosmanith]

> 
> > > can you share with us what you want to do with this?
> > 
> > I need the pci_dev to reconfigure ahci-controllers so that they look like
> > having been initialised by BIOS at reboot time.
> 
> isn't it better to do this in the ahci driver itself instead?

guess what I'm doing.

> it for sure will be orders of magnitude easier....

yes?
 

Re: finding pci_dev from scsi_device

[Arjan van de Ven]

> > can you share with us what you want to do with this?
> 
> I need the pci_dev to reconfigure ahci-controllers so that they look like
> having been initialised by BIOS at reboot time.

isn't it better to do this in the ahci driver itself instead? it for
sure will be orders of magnitude easier....

Re: finding pci_dev from scsi_device

[Herbert Rosmanith]

> isn't it better to do this in the ahci driver itself instead? it for
> sure will be orders of magnitude easier....

drivers/scsi/ahci.c:

// XXX added herp
static int ahci_ioctl(struct scsi_device *scsidev, int cmd, void __user *arg) {
...

For some reason, I have to use an ioctl to reconfigure the controller.
This means that I don't have the "struct pci_dev *pdev" from ahci_init_one
and ahci_remove_one.

I could store a pointer to pci_dev by extending "struct ahci_host_priv",
but before doing this, I'm trying to figure out if there's a "correct"
way of finding a pci_dev from a scsi_device.

>From the scsi_device, I know I can get a "struct ata_port", from there
a "struct Scsi_Host", a "struct ata_host_set" and even a generic
"struct device *".

Now all that's missing is a pointer to "struct pci_dev". Is there a function
to enumerate all "struct device", in that case I could compare
"struct pci_dev -> dev", if the pointers match, I've found it.

kind regards,
h.rosmanith

Re: finding pci_dev from scsi_device

[Arjan van de Ven]

On Mon, 2006-06-26 at 16:24 +0200, Herbert Rosmanith wrote:
> > 
> > > > can you share with us what you want to do with this?
> > > 
> > > I need the pci_dev to reconfigure ahci-controllers so that they look like
> > > having been initialised by BIOS at reboot time.
> > 
> > isn't it better to do this in the ahci driver itself instead?
> 
> guess what I'm doing.
> 
> > it for sure will be orders of magnitude easier....
> 
> yes?

static int ahci_host_init(struct ata_probe_ent *probe_ent)
{
        struct ahci_host_priv *hpriv = probe_ent->private_data;
        struct pci_dev *pdev = to_pci_dev(probe_ent->dev);

as you can see, you can easily go from an ata_probe_ent to a pci
device... 

also.. you could just put your code into the remove hook... :)

Re: finding pci_dev from scsi_device

[Herbert Rosmanith]

> >From the scsi_device, I know I can get a "struct ata_port", from there
> a "struct Scsi_Host", a "struct ata_host_set" and even a generic
> "struct device *".

Arjan> static int ahci_host_init(struct ata_probe_ent *probe_ent)
Arjan> {
Arjan>         struct ahci_host_priv *hpriv = probe_ent->private_data;
Arjan>         struct pci_dev *pdev = to_pci_dev(probe_ent->dev);
Arjan> 
Arjan> as you can see, you can easily go from an ata_probe_ent to a pci
Arjan> device...

ah! that looks promising. looks like "to_pci_dev" is what I've been
searching.

thanks, I'll try immediately :)

kind regards,
h.rosmanith

Re: finding pci_dev from scsi_device

[Herbert Rosmanith]

> 
> also.. you could just put your code into the remove hook... :)

oh by the way, that's the reason why I need to find the pci-pointer myself.
in our environment, the remove hook is never called.

kind regards,
h.rosmanith

Re: finding pci_dev from scsi_device

[Herbert Rosmanith]

>         struct pci_dev *pdev = to_pci_dev(probe_ent->dev);
> 
> as you can see, you can easily go from an ata_probe_ent to a pci
> device... 

just for the sake of completeness:

static int ahci_ioctl(struct scsi_device *scsidev, int cmd, void __user *arg) {
struct pci_dev *pdev;

	pdev=to_pci_dev(((struct ata_port *)&scsidev->host->hostdata[0])->host_set->dev);

kind regards,
h.rosmanith