linux-kernel - Re: [PATCH 7/7] s390/PCI: Use generic pci_enable

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Date:	Mon, 3 Mar 2014 14:35:04 +0100 (CET)
From:	Sebastian Ott <sebott@...ux.vnet.ibm.com>
To:	Bjorn Helgaas <bhelgaas@...gle.com>
cc:	linux-pci@...r.kernel.org, Jan Glauber <jang@...ux.vnet.ibm.com>,
	Heiko Carstens <heiko.carstens@...ibm.com>,
	linux-kernel@...r.kernel.org,
	Martin Schwidefsky <schwidefsky@...ibm.com>,
	linux390@...ibm.com
Subject: Re: [PATCH 7/7] s390/PCI: Use generic pci_enable_resources()

Hello Bjorn,

On Wed, 26 Feb 2014, Bjorn Helgaas wrote:

> The generic pci_enable_resources() does essentially the same thing as the
> code in the s390 version of pcibios_enable_device().
> 
> There are differences, but I don't think any of them are a problem.  The
> generic code:
> 
>   - Checks everything up to PCI_NUM_RESOURCES, not PCI_BAR_COUNT (6), so
>     we'll now check the ROM resource, IOV resources, and bridge windows.
> 
>   - Checks for res->flags & IORESOURCE_UNSET.  The s390 code never sets
>     IORESOURCE_UNSET, so this isn't a problem.
> 
>   - Checks res->parent.  The s390 pcibios_add_device() calls
>     pci_claim_resource() on all BARs (except ROM, IOV, and bridge windows)
>     so this isn't a problem either.
> 
> Signed-off-by: Bjorn Helgaas <bhelgaas@...gle.com>
> CC: Martin Schwidefsky <schwidefsky@...ibm.com>
> CC: Heiko Carstens <heiko.carstens@...ibm.com>
> CC: Sebastian Ott <sebott@...ux.vnet.ibm.com>
> CC: Jan Glauber <jang@...ux.vnet.ibm.com>
> CC: linux390@...ibm.com
> ---
>  arch/s390/pci/pci.c |   13 +------------
>  1 file changed, 1 insertion(+), 12 deletions(-)
> 
> diff --git a/arch/s390/pci/pci.c b/arch/s390/pci/pci.c
> index 66670ff262a0..7d5fcaed3361 100644
> --- a/arch/s390/pci/pci.c
> +++ b/arch/s390/pci/pci.c
> @@ -695,18 +695,7 @@ int pcibios_enable_device(struct pci_dev *pdev, int mask)
>  	zpci_fmb_enable_device(zdev);
>  	zpci_map_resources(zdev);
> 
> -	pci_read_config_word(pdev, PCI_COMMAND, &cmd);
> -	for (i = 0; i < PCI_BAR_COUNT; i++) {
> -		res = &pdev->resource[i];
> -
> -		if (res->flags & IORESOURCE_IO)
> -			return -EINVAL;
> -
> -		if (res->flags & IORESOURCE_MEM)
> -			cmd |= PCI_COMMAND_MEMORY;
> -	}
> -	pci_write_config_word(pdev, PCI_COMMAND, cmd);
> -	return 0;
> +	return pci_enable_resources(pdev, mask);
>  }
> 
>  void pcibios_disable_device(struct pci_dev *pdev)
> 

Let's also remove some now unused variables (updated patch below). Other
than that:

Acked-by: Sebastian Ott <sebott@...ux.vnet.ibm.com>

Regards,
Sebastian
---
s390/PCI: Use generic pci_enable_resources()

The generic pci_enable_resources() does essentially the same thing as the
code in the s390 version of pcibios_enable_device().

There are differences, but I don't think any of them are a problem.  The
generic code:

  - Checks everything up to PCI_NUM_RESOURCES, not PCI_BAR_COUNT (6), so
    we'll now check the ROM resource, IOV resources, and bridge windows.

  - Checks for res->flags & IORESOURCE_UNSET.  The s390 code never sets
    IORESOURCE_UNSET, so this isn't a problem.

  - Checks res->parent.  The s390 pcibios_add_device() calls
    pci_claim_resource() on all BARs (except ROM, IOV, and bridge windows)
    so this isn't a problem either.

Signed-off-by: Bjorn Helgaas <bhelgaas@...gle.com>
CC: Martin Schwidefsky <schwidefsky@...ibm.com>
CC: Heiko Carstens <heiko.carstens@...ibm.com>
CC: Sebastian Ott <sebott@...ux.vnet.ibm.com>
CC: Jan Glauber <jang@...ux.vnet.ibm.com>
CC: linux390@...ibm.com
---
 arch/s390/pci/pci.c |   16 +---------------
 1 file changed, 1 insertion(+), 15 deletions(-)

--- a/arch/s390/pci/pci.c
+++ b/arch/s390/pci/pci.c
@@ -686,27 +686,13 @@ int pcibios_add_device(struct pci_dev *p
 int pcibios_enable_device(struct pci_dev *pdev, int mask)
 {
 	struct zpci_dev *zdev = get_zdev(pdev);
-	struct resource *res;
-	u16 cmd;
-	int i;
 
 	zdev->pdev = pdev;
 	zpci_debug_init_device(zdev);
 	zpci_fmb_enable_device(zdev);
 	zpci_map_resources(zdev);
 
-	pci_read_config_word(pdev, PCI_COMMAND, &cmd);
-	for (i = 0; i < PCI_BAR_COUNT; i++) {
-		res = &pdev->resource[i];
-
-		if (res->flags & IORESOURCE_IO)
-			return -EINVAL;
-
-		if (res->flags & IORESOURCE_MEM)
-			cmd |= PCI_COMMAND_MEMORY;
-	}
-	pci_write_config_word(pdev, PCI_COMMAND, cmd);
-	return 0;
+	return pci_enable_resources(pdev, mask);
 }
 
 void pcibios_disable_device(struct pci_dev *pdev)

--
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