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Message-Id: <200804010957.16459.bjorn.helgaas@hp.com>
Date: Tue, 1 Apr 2008 09:57:15 -0600
From: Bjorn Helgaas <bjorn.helgaas@...com>
To: akpm@...ux-foundation.org
Cc: mm-commits@...r.kernel.org, davem@...emloft.net, greg@...ah.com,
m.kozlowski@...land.pl,
Benjamin Herrenschmidt <benh@...nel.crashing.org>,
linux-kernel@...r.kernel.org, Tony Luck <tony.luck@...el.com>,
linux-ia64@...r.kernel.org,
Ivan Kokshaysky <ink@...assic.park.msu.ru>
Subject: Re: + revert-gregkh-pci-pci-x86-use-generic-pci_enable_resources.patch added to -mm tree
On Friday 28 March 2008 05:48:47 pm akpm@...ux-foundation.org wrote:
>
> The patch titled
> revert gregkh-pci-pci-x86-use-generic-pci_enable_resources
> has been added to the -mm tree. Its filename is
> revert-gregkh-pci-pci-x86-use-generic-pci_enable_resources.patch
OK, I'm not sure where we are with this. Ben listed arches where
the generic pci_enable_resources() should be safe: x86, alpha, and
powerpc. I think we should also include ia64, since I work on that.
If there's no objection to those arches, how should we move forward?
Since Andrew put in "revert gregkh-pci" patches rather than just
dropping things, I assume the original patches are in Greg KH's tree.
Can we just drop the "revert gregkh" patches for x86, alpha, powerpc,
and ia64?
Bjorn
> ------------------------------------------------------
> Subject: revert gregkh-pci-pci-x86-use-generic-pci_enable_resources
> From: Andrew Morton <akpm@...ux-foundation.org>
>
> On Fri, 28 Mar 2008 16:10:11 -0700 (PDT) David Miller <davem@...emloft.net> wrote:
>
> > From: Mariusz Kozlowski <m.kozlowski@...land.pl>
> > Date: Fri, 28 Mar 2008 23:52:10 +0100
> >
> > > The gregkh-pci-pci-sparc64-use-generic-pci_enable_resources.patch which
> > > replaces arch-specific code with generic pci_enable_resources() makes my sparc64
> > > box unable to boot (that's what quilt bisection says). At first I see these messages:
> >
> > Yes, that generic code won't work because of the NULL
> > r->parent check.
> >
> > Alpha, ARM, V32, FRV, IA64, MIPS, MN10300, PARISC, PPC,
> > SH, V850, X86, and Xtensa are all likely to run into
> > problems because of this change.
> >
> > The only platform that did the check as a test of r->parent
> > being NULL is Powerpc.
> >
> > The rest either didn't check (like sparc64), or tested it by going:
> >
> > if (!r->start && r->end)
> >
> > So the amount of potential breakage from this change is enormous.
>
> Cc: Bjorn Helgaas <bjorn.helgaas@...com>
> Cc: Greg KH <greg@...ah.com>
> Signed-off-by: Andrew Morton <akpm@...ux-foundation.org>
> ---
>
> arch/x86/pci/common.c | 2 +-
> arch/x86/pci/i386.c | 38 ++++++++++++++++++++++++++++++++++++++
> arch/x86/pci/pci.h | 1 +
> 3 files changed, 40 insertions(+), 1 deletion(-)
>
> diff -puN arch/x86/pci/common.c~revert-gregkh-pci-pci-x86-use-generic-pci_enable_resources arch/x86/pci/common.c
> --- a/arch/x86/pci/common.c~revert-gregkh-pci-pci-x86-use-generic-pci_enable_resources
> +++ a/arch/x86/pci/common.c
> @@ -466,7 +466,7 @@ int pcibios_enable_device(struct pci_dev
> {
> int err;
>
> - if ((err = pci_enable_resources(dev, mask)) < 0)
> + if ((err = pcibios_enable_resources(dev, mask)) < 0)
> return err;
>
> if (!dev->msi_enabled)
> diff -puN arch/x86/pci/i386.c~revert-gregkh-pci-pci-x86-use-generic-pci_enable_resources arch/x86/pci/i386.c
> --- a/arch/x86/pci/i386.c~revert-gregkh-pci-pci-x86-use-generic-pci_enable_resources
> +++ a/arch/x86/pci/i386.c
> @@ -238,6 +238,44 @@ void __init pcibios_resource_survey(void
> */
> fs_initcall(pcibios_assign_resources);
>
> +int pcibios_enable_resources(struct pci_dev *dev, int mask)
> +{
> + u16 cmd, old_cmd;
> + int idx;
> + struct resource *r;
> +
> + pci_read_config_word(dev, PCI_COMMAND, &cmd);
> + old_cmd = cmd;
> + for (idx = 0; idx < PCI_NUM_RESOURCES; idx++) {
> + /* Only set up the requested stuff */
> + if (!(mask & (1 << idx)))
> + continue;
> +
> + r = &dev->resource[idx];
> + if (!(r->flags & (IORESOURCE_IO | IORESOURCE_MEM)))
> + continue;
> + if ((idx == PCI_ROM_RESOURCE) &&
> + (!(r->flags & IORESOURCE_ROM_ENABLE)))
> + continue;
> + if (!r->start && r->end) {
> + printk(KERN_ERR "PCI: Device %s not available "
> + "because of resource %d collisions\n",
> + pci_name(dev), idx);
> + return -EINVAL;
> + }
> + if (r->flags & IORESOURCE_IO)
> + cmd |= PCI_COMMAND_IO;
> + if (r->flags & IORESOURCE_MEM)
> + cmd |= PCI_COMMAND_MEMORY;
> + }
> + if (cmd != old_cmd) {
> + printk("PCI: Enabling device %s (%04x -> %04x)\n",
> + pci_name(dev), old_cmd, cmd);
> + pci_write_config_word(dev, PCI_COMMAND, cmd);
> + }
> + return 0;
> +}
> +
> /*
> * If we set up a device for bus mastering, we need to check the latency
> * timer as certain crappy BIOSes forget to set it properly.
> diff -puN arch/x86/pci/pci.h~revert-gregkh-pci-pci-x86-use-generic-pci_enable_resources arch/x86/pci/pci.h
> --- a/arch/x86/pci/pci.h~revert-gregkh-pci-pci-x86-use-generic-pci_enable_resources
> +++ a/arch/x86/pci/pci.h
> @@ -42,6 +42,7 @@ enum pci_bf_sort_state {
> extern unsigned int pcibios_max_latency;
>
> void pcibios_resource_survey(void);
> +int pcibios_enable_resources(struct pci_dev *, int);
>
> /* pci-pc.c */
>
> _
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