Re: [PATCH v2 2/4] PCI: pci-host-generic: Fix lookup of linux,pci-probe-only property
On Fri, Aug 14, 2015 at 09:26:21PM +0100, Bjorn Helgaas wrote: > On Fri, Aug 14, 2015 at 11:43 AM, Will Deacon wrote: > > On Fri, Aug 14, 2015 at 05:40:51PM +0100, Bjorn Helgaas wrote: > >> Do we need support for pci-probe-only in pci-host-generic at all? > >> You're removing the use in amd-overdrive.dts, and there are no other > >> DTs in the kernel tree that mention it. > >> > >> If we can live without it, that would be nice. It seems like a relic from > >> days when we couldn't reliably assign resources. (I'm not saying we can do > >> that reliably even today, but I'd rather make it reliable than turn it > >> off.) > > > > Kvmtool certainly uses it (and generates its own DT, hence why you don't > > see it in mainline). Not sure about qemu, though. > > Do you know why kvmtool wants probe-only? Would something break if we > didn't support probe-only? I guess we'd be looking for a case where > Linux assigns resources and that assignment doesn't work with kvmtool? It's basically because the BARs aren't writable other than to find the region size. It could fixed with a bit of pain, but it doesn't help older kvmtools that do work with mainline today. Will -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v2 2/4] PCI: pci-host-generic: Fix lookup of linux,pci-probe-only property
On Fri, Aug 14, 2015 at 09:26:21PM +0100, Bjorn Helgaas wrote: On Fri, Aug 14, 2015 at 11:43 AM, Will Deacon will.dea...@arm.com wrote: On Fri, Aug 14, 2015 at 05:40:51PM +0100, Bjorn Helgaas wrote: Do we need support for pci-probe-only in pci-host-generic at all? You're removing the use in amd-overdrive.dts, and there are no other DTs in the kernel tree that mention it. If we can live without it, that would be nice. It seems like a relic from days when we couldn't reliably assign resources. (I'm not saying we can do that reliably even today, but I'd rather make it reliable than turn it off.) Kvmtool certainly uses it (and generates its own DT, hence why you don't see it in mainline). Not sure about qemu, though. Do you know why kvmtool wants probe-only? Would something break if we didn't support probe-only? I guess we'd be looking for a case where Linux assigns resources and that assignment doesn't work with kvmtool? It's basically because the BARs aren't writable other than to find the region size. It could fixed with a bit of pain, but it doesn't help older kvmtools that do work with mainline today. Will -- To unsubscribe from this list: send the line unsubscribe linux-kernel in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Re: [PATCH v2 2/4] PCI: pci-host-generic: Fix lookup of linux,pci-probe-only property
On Fri, Aug 14, 2015 at 11:43 AM, Will Deacon wrote:
> On Fri, Aug 14, 2015 at 05:40:51PM +0100, Bjorn Helgaas wrote:
>> On Fri, Aug 14, 2015 at 05:19:17PM +0100, Marc Zyngier wrote:
>> > When pci-host-generic looks for the probe-only property, it seems
>> > to trust the DT to be correctly written, and assumes that there
>> > is a parameter to the property.
>> >
>> > Unfortunately, this is not always the case, and some firmware expose
>> > this property naked. The driver ends up making a decision based on
>> > whatever the property pointer points to, which is likely to be junk.
>> >
>> > Switch to the common of_pci.c implementation that doesn't suffer
>> > from this problem.
>> >
>> > Signed-off-by: Marc Zyngier
>> > ---
>> > drivers/pci/host/pci-host-generic.c | 9 +
>> > 1 file changed, 1 insertion(+), 8 deletions(-)
>> >
>> > diff --git a/drivers/pci/host/pci-host-generic.c
>> > b/drivers/pci/host/pci-host-generic.c
>> > index 265dd25..545ff4e 100644
>> > --- a/drivers/pci/host/pci-host-generic.c
>> > +++ b/drivers/pci/host/pci-host-generic.c
>> > @@ -210,7 +210,6 @@ static int gen_pci_probe(struct platform_device *pdev)
>> > int err;
>> > const char *type;
>> > const struct of_device_id *of_id;
>> > - const int *prop;
>> > struct device *dev = >dev;
>> > struct device_node *np = dev->of_node;
>> > struct gen_pci *pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
>> > @@ -225,13 +224,7 @@ static int gen_pci_probe(struct platform_device *pdev)
>> > return -EINVAL;
>> > }
>> >
>> > - prop = of_get_property(of_chosen, "linux,pci-probe-only", NULL);
>> > - if (prop) {
>> > - if (*prop)
>> > - pci_add_flags(PCI_PROBE_ONLY);
>> > - else
>> > - pci_clear_flags(PCI_PROBE_ONLY);
>> > - }
>> > + of_pci_check_probe_only(of_chosen);
>>
>> Do we need support for pci-probe-only in pci-host-generic at all?
>> You're removing the use in amd-overdrive.dts, and there are no other
>> DTs in the kernel tree that mention it.
>>
>> If we can live without it, that would be nice. It seems like a relic from
>> days when we couldn't reliably assign resources. (I'm not saying we can do
>> that reliably even today, but I'd rather make it reliable than turn it
>> off.)
>
> Kvmtool certainly uses it (and generates its own DT, hence why you don't
> see it in mainline). Not sure about qemu, though.
Do you know why kvmtool wants probe-only? Would something break if we
didn't support probe-only? I guess we'd be looking for a case where
Linux assigns resources and that assignment doesn't work with kvmtool?
"pci-probe-only" doesn't appear in qemu
(git://git.qemu-project.org/qemu.git). (I guess Alexander confirmed
that later.)
Alexander wrote:
> QEMU definitely doesn't do proble-only.
> Is this driver used on real PPC machines too?
I think you're asking about pci-host-generic.c, and the answer is
"no," because pci-host-generic.c currently depends on CONFIG_ARM.
Bjorn
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Re: [PATCH v2 2/4] PCI: pci-host-generic: Fix lookup of linux,pci-probe-only property
> On 14.08.2015, at 09:43, Will Deacon wrote:
>
> On Fri, Aug 14, 2015 at 05:40:51PM +0100, Bjorn Helgaas wrote:
>> On Fri, Aug 14, 2015 at 05:19:17PM +0100, Marc Zyngier wrote:
>>> When pci-host-generic looks for the probe-only property, it seems
>>> to trust the DT to be correctly written, and assumes that there
>>> is a parameter to the property.
>>>
>>> Unfortunately, this is not always the case, and some firmware expose
>>> this property naked. The driver ends up making a decision based on
>>> whatever the property pointer points to, which is likely to be junk.
>>>
>>> Switch to the common of_pci.c implementation that doesn't suffer
>>> from this problem.
>>>
>>> Signed-off-by: Marc Zyngier
>>> ---
>>> drivers/pci/host/pci-host-generic.c | 9 +
>>> 1 file changed, 1 insertion(+), 8 deletions(-)
>>>
>>> diff --git a/drivers/pci/host/pci-host-generic.c
>>> b/drivers/pci/host/pci-host-generic.c
>>> index 265dd25..545ff4e 100644
>>> --- a/drivers/pci/host/pci-host-generic.c
>>> +++ b/drivers/pci/host/pci-host-generic.c
>>> @@ -210,7 +210,6 @@ static int gen_pci_probe(struct platform_device *pdev)
>>> int err;
>>> const char *type;
>>> const struct of_device_id *of_id;
>>> - const int *prop;
>>> struct device *dev = >dev;
>>> struct device_node *np = dev->of_node;
>>> struct gen_pci *pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
>>> @@ -225,13 +224,7 @@ static int gen_pci_probe(struct platform_device *pdev)
>>> return -EINVAL;
>>> }
>>>
>>> - prop = of_get_property(of_chosen, "linux,pci-probe-only", NULL);
>>> - if (prop) {
>>> - if (*prop)
>>> - pci_add_flags(PCI_PROBE_ONLY);
>>> - else
>>> - pci_clear_flags(PCI_PROBE_ONLY);
>>> - }
>>> + of_pci_check_probe_only(of_chosen);
>>
>> Do we need support for pci-probe-only in pci-host-generic at all?
>> You're removing the use in amd-overdrive.dts, and there are no other
>> DTs in the kernel tree that mention it.
>>
>> If we can live without it, that would be nice. It seems like a relic from
>> days when we couldn't reliably assign resources. (I'm not saying we can do
>> that reliably even today, but I'd rather make it reliable than turn it
>> off.)
>
> Kvmtool certainly uses it (and generates its own DT, hence why you don't
> see it in mainline). Not sure about qemu, though.
QEMU definitely doesn't do proble-only. Is this driver used on real PPC
machines too? In that case you also won't see the dt, because it comes with the
hardware ;).
Alex
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Re: [PATCH v2 2/4] PCI: pci-host-generic: Fix lookup of linux,pci-probe-only property
On Fri, Aug 14, 2015 at 05:19:17PM +0100, Marc Zyngier wrote:
> When pci-host-generic looks for the probe-only property, it seems
> to trust the DT to be correctly written, and assumes that there
> is a parameter to the property.
>
> Unfortunately, this is not always the case, and some firmware expose
> this property naked. The driver ends up making a decision based on
> whatever the property pointer points to, which is likely to be junk.
>
> Switch to the common of_pci.c implementation that doesn't suffer
> from this problem.
>
> Signed-off-by: Marc Zyngier
> ---
> drivers/pci/host/pci-host-generic.c | 9 +
> 1 file changed, 1 insertion(+), 8 deletions(-)
>
> diff --git a/drivers/pci/host/pci-host-generic.c
> b/drivers/pci/host/pci-host-generic.c
> index 265dd25..545ff4e 100644
> --- a/drivers/pci/host/pci-host-generic.c
> +++ b/drivers/pci/host/pci-host-generic.c
> @@ -210,7 +210,6 @@ static int gen_pci_probe(struct platform_device *pdev)
> int err;
> const char *type;
> const struct of_device_id *of_id;
> - const int *prop;
> struct device *dev = >dev;
> struct device_node *np = dev->of_node;
> struct gen_pci *pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
> @@ -225,13 +224,7 @@ static int gen_pci_probe(struct platform_device *pdev)
> return -EINVAL;
> }
>
> - prop = of_get_property(of_chosen, "linux,pci-probe-only", NULL);
> - if (prop) {
> - if (*prop)
> - pci_add_flags(PCI_PROBE_ONLY);
> - else
> - pci_clear_flags(PCI_PROBE_ONLY);
> - }
> + of_pci_check_probe_only(of_chosen);
You could probably just make this take void, as the probe-only property
is always in the /chosen node.
Either way:
Acked-by: Will Deacon
Will
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Re: [PATCH v2 2/4] PCI: pci-host-generic: Fix lookup of linux,pci-probe-only property
On Fri, Aug 14, 2015 at 05:40:51PM +0100, Bjorn Helgaas wrote:
> On Fri, Aug 14, 2015 at 05:19:17PM +0100, Marc Zyngier wrote:
> > When pci-host-generic looks for the probe-only property, it seems
> > to trust the DT to be correctly written, and assumes that there
> > is a parameter to the property.
> >
> > Unfortunately, this is not always the case, and some firmware expose
> > this property naked. The driver ends up making a decision based on
> > whatever the property pointer points to, which is likely to be junk.
> >
> > Switch to the common of_pci.c implementation that doesn't suffer
> > from this problem.
> >
> > Signed-off-by: Marc Zyngier
> > ---
> > drivers/pci/host/pci-host-generic.c | 9 +
> > 1 file changed, 1 insertion(+), 8 deletions(-)
> >
> > diff --git a/drivers/pci/host/pci-host-generic.c
> > b/drivers/pci/host/pci-host-generic.c
> > index 265dd25..545ff4e 100644
> > --- a/drivers/pci/host/pci-host-generic.c
> > +++ b/drivers/pci/host/pci-host-generic.c
> > @@ -210,7 +210,6 @@ static int gen_pci_probe(struct platform_device *pdev)
> > int err;
> > const char *type;
> > const struct of_device_id *of_id;
> > - const int *prop;
> > struct device *dev = >dev;
> > struct device_node *np = dev->of_node;
> > struct gen_pci *pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
> > @@ -225,13 +224,7 @@ static int gen_pci_probe(struct platform_device *pdev)
> > return -EINVAL;
> > }
> >
> > - prop = of_get_property(of_chosen, "linux,pci-probe-only", NULL);
> > - if (prop) {
> > - if (*prop)
> > - pci_add_flags(PCI_PROBE_ONLY);
> > - else
> > - pci_clear_flags(PCI_PROBE_ONLY);
> > - }
> > + of_pci_check_probe_only(of_chosen);
>
> Do we need support for pci-probe-only in pci-host-generic at all?
> You're removing the use in amd-overdrive.dts, and there are no other
> DTs in the kernel tree that mention it.
>
> If we can live without it, that would be nice. It seems like a relic from
> days when we couldn't reliably assign resources. (I'm not saying we can do
> that reliably even today, but I'd rather make it reliable than turn it
> off.)
Kvmtool certainly uses it (and generates its own DT, hence why you don't
see it in mainline). Not sure about qemu, though.
Will
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Re: [PATCH v2 2/4] PCI: pci-host-generic: Fix lookup of linux,pci-probe-only property
On Fri, Aug 14, 2015 at 05:19:17PM +0100, Marc Zyngier wrote:
> When pci-host-generic looks for the probe-only property, it seems
> to trust the DT to be correctly written, and assumes that there
> is a parameter to the property.
>
> Unfortunately, this is not always the case, and some firmware expose
> this property naked. The driver ends up making a decision based on
> whatever the property pointer points to, which is likely to be junk.
>
> Switch to the common of_pci.c implementation that doesn't suffer
> from this problem.
>
> Signed-off-by: Marc Zyngier
> ---
> drivers/pci/host/pci-host-generic.c | 9 +
> 1 file changed, 1 insertion(+), 8 deletions(-)
>
> diff --git a/drivers/pci/host/pci-host-generic.c
> b/drivers/pci/host/pci-host-generic.c
> index 265dd25..545ff4e 100644
> --- a/drivers/pci/host/pci-host-generic.c
> +++ b/drivers/pci/host/pci-host-generic.c
> @@ -210,7 +210,6 @@ static int gen_pci_probe(struct platform_device *pdev)
> int err;
> const char *type;
> const struct of_device_id *of_id;
> - const int *prop;
> struct device *dev = >dev;
> struct device_node *np = dev->of_node;
> struct gen_pci *pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
> @@ -225,13 +224,7 @@ static int gen_pci_probe(struct platform_device *pdev)
> return -EINVAL;
> }
>
> - prop = of_get_property(of_chosen, "linux,pci-probe-only", NULL);
> - if (prop) {
> - if (*prop)
> - pci_add_flags(PCI_PROBE_ONLY);
> - else
> - pci_clear_flags(PCI_PROBE_ONLY);
> - }
> + of_pci_check_probe_only(of_chosen);
Do we need support for pci-probe-only in pci-host-generic at all?
You're removing the use in amd-overdrive.dts, and there are no other
DTs in the kernel tree that mention it.
If we can live without it, that would be nice. It seems like a relic from
days when we couldn't reliably assign resources. (I'm not saying we can do
that reliably even today, but I'd rather make it reliable than turn it
off.)
> of_id = of_match_node(gen_pci_of_match, np);
> pci->cfg.ops = of_id->data;
> --
> 2.1.4
>
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[PATCH v2 2/4] PCI: pci-host-generic: Fix lookup of linux,pci-probe-only property
When pci-host-generic looks for the probe-only property, it seems
to trust the DT to be correctly written, and assumes that there
is a parameter to the property.
Unfortunately, this is not always the case, and some firmware expose
this property naked. The driver ends up making a decision based on
whatever the property pointer points to, which is likely to be junk.
Switch to the common of_pci.c implementation that doesn't suffer
from this problem.
Signed-off-by: Marc Zyngier
---
drivers/pci/host/pci-host-generic.c | 9 +
1 file changed, 1 insertion(+), 8 deletions(-)
diff --git a/drivers/pci/host/pci-host-generic.c
b/drivers/pci/host/pci-host-generic.c
index 265dd25..545ff4e 100644
--- a/drivers/pci/host/pci-host-generic.c
+++ b/drivers/pci/host/pci-host-generic.c
@@ -210,7 +210,6 @@ static int gen_pci_probe(struct platform_device *pdev)
int err;
const char *type;
const struct of_device_id *of_id;
- const int *prop;
struct device *dev = >dev;
struct device_node *np = dev->of_node;
struct gen_pci *pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
@@ -225,13 +224,7 @@ static int gen_pci_probe(struct platform_device *pdev)
return -EINVAL;
}
- prop = of_get_property(of_chosen, "linux,pci-probe-only", NULL);
- if (prop) {
- if (*prop)
- pci_add_flags(PCI_PROBE_ONLY);
- else
- pci_clear_flags(PCI_PROBE_ONLY);
- }
+ of_pci_check_probe_only(of_chosen);
of_id = of_match_node(gen_pci_of_match, np);
pci->cfg.ops = of_id->data;
--
2.1.4
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Re: [PATCH v2 2/4] PCI: pci-host-generic: Fix lookup of linux,pci-probe-only property
On Fri, Aug 14, 2015 at 11:43 AM, Will Deacon will.dea...@arm.com wrote:
On Fri, Aug 14, 2015 at 05:40:51PM +0100, Bjorn Helgaas wrote:
On Fri, Aug 14, 2015 at 05:19:17PM +0100, Marc Zyngier wrote:
When pci-host-generic looks for the probe-only property, it seems
to trust the DT to be correctly written, and assumes that there
is a parameter to the property.
Unfortunately, this is not always the case, and some firmware expose
this property naked. The driver ends up making a decision based on
whatever the property pointer points to, which is likely to be junk.
Switch to the common of_pci.c implementation that doesn't suffer
from this problem.
Signed-off-by: Marc Zyngier marc.zyng...@arm.com
---
drivers/pci/host/pci-host-generic.c | 9 +
1 file changed, 1 insertion(+), 8 deletions(-)
diff --git a/drivers/pci/host/pci-host-generic.c
b/drivers/pci/host/pci-host-generic.c
index 265dd25..545ff4e 100644
--- a/drivers/pci/host/pci-host-generic.c
+++ b/drivers/pci/host/pci-host-generic.c
@@ -210,7 +210,6 @@ static int gen_pci_probe(struct platform_device *pdev)
int err;
const char *type;
const struct of_device_id *of_id;
- const int *prop;
struct device *dev = pdev-dev;
struct device_node *np = dev-of_node;
struct gen_pci *pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
@@ -225,13 +224,7 @@ static int gen_pci_probe(struct platform_device *pdev)
return -EINVAL;
}
- prop = of_get_property(of_chosen, linux,pci-probe-only, NULL);
- if (prop) {
- if (*prop)
- pci_add_flags(PCI_PROBE_ONLY);
- else
- pci_clear_flags(PCI_PROBE_ONLY);
- }
+ of_pci_check_probe_only(of_chosen);
Do we need support for pci-probe-only in pci-host-generic at all?
You're removing the use in amd-overdrive.dts, and there are no other
DTs in the kernel tree that mention it.
If we can live without it, that would be nice. It seems like a relic from
days when we couldn't reliably assign resources. (I'm not saying we can do
that reliably even today, but I'd rather make it reliable than turn it
off.)
Kvmtool certainly uses it (and generates its own DT, hence why you don't
see it in mainline). Not sure about qemu, though.
Do you know why kvmtool wants probe-only? Would something break if we
didn't support probe-only? I guess we'd be looking for a case where
Linux assigns resources and that assignment doesn't work with kvmtool?
pci-probe-only doesn't appear in qemu
(git://git.qemu-project.org/qemu.git). (I guess Alexander confirmed
that later.)
Alexander wrote:
QEMU definitely doesn't do proble-only.
Is this driver used on real PPC machines too?
I think you're asking about pci-host-generic.c, and the answer is
no, because pci-host-generic.c currently depends on CONFIG_ARM.
Bjorn
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Re: [PATCH v2 2/4] PCI: pci-host-generic: Fix lookup of linux,pci-probe-only property
On Fri, Aug 14, 2015 at 05:19:17PM +0100, Marc Zyngier wrote:
When pci-host-generic looks for the probe-only property, it seems
to trust the DT to be correctly written, and assumes that there
is a parameter to the property.
Unfortunately, this is not always the case, and some firmware expose
this property naked. The driver ends up making a decision based on
whatever the property pointer points to, which is likely to be junk.
Switch to the common of_pci.c implementation that doesn't suffer
from this problem.
Signed-off-by: Marc Zyngier marc.zyng...@arm.com
---
drivers/pci/host/pci-host-generic.c | 9 +
1 file changed, 1 insertion(+), 8 deletions(-)
diff --git a/drivers/pci/host/pci-host-generic.c
b/drivers/pci/host/pci-host-generic.c
index 265dd25..545ff4e 100644
--- a/drivers/pci/host/pci-host-generic.c
+++ b/drivers/pci/host/pci-host-generic.c
@@ -210,7 +210,6 @@ static int gen_pci_probe(struct platform_device *pdev)
int err;
const char *type;
const struct of_device_id *of_id;
- const int *prop;
struct device *dev = pdev-dev;
struct device_node *np = dev-of_node;
struct gen_pci *pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
@@ -225,13 +224,7 @@ static int gen_pci_probe(struct platform_device *pdev)
return -EINVAL;
}
- prop = of_get_property(of_chosen, linux,pci-probe-only, NULL);
- if (prop) {
- if (*prop)
- pci_add_flags(PCI_PROBE_ONLY);
- else
- pci_clear_flags(PCI_PROBE_ONLY);
- }
+ of_pci_check_probe_only(of_chosen);
You could probably just make this take void, as the probe-only property
is always in the /chosen node.
Either way:
Acked-by: Will Deacon will.dea...@arm.com
Will
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[PATCH v2 2/4] PCI: pci-host-generic: Fix lookup of linux,pci-probe-only property
When pci-host-generic looks for the probe-only property, it seems
to trust the DT to be correctly written, and assumes that there
is a parameter to the property.
Unfortunately, this is not always the case, and some firmware expose
this property naked. The driver ends up making a decision based on
whatever the property pointer points to, which is likely to be junk.
Switch to the common of_pci.c implementation that doesn't suffer
from this problem.
Signed-off-by: Marc Zyngier marc.zyng...@arm.com
---
drivers/pci/host/pci-host-generic.c | 9 +
1 file changed, 1 insertion(+), 8 deletions(-)
diff --git a/drivers/pci/host/pci-host-generic.c
b/drivers/pci/host/pci-host-generic.c
index 265dd25..545ff4e 100644
--- a/drivers/pci/host/pci-host-generic.c
+++ b/drivers/pci/host/pci-host-generic.c
@@ -210,7 +210,6 @@ static int gen_pci_probe(struct platform_device *pdev)
int err;
const char *type;
const struct of_device_id *of_id;
- const int *prop;
struct device *dev = pdev-dev;
struct device_node *np = dev-of_node;
struct gen_pci *pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
@@ -225,13 +224,7 @@ static int gen_pci_probe(struct platform_device *pdev)
return -EINVAL;
}
- prop = of_get_property(of_chosen, linux,pci-probe-only, NULL);
- if (prop) {
- if (*prop)
- pci_add_flags(PCI_PROBE_ONLY);
- else
- pci_clear_flags(PCI_PROBE_ONLY);
- }
+ of_pci_check_probe_only(of_chosen);
of_id = of_match_node(gen_pci_of_match, np);
pci-cfg.ops = of_id-data;
--
2.1.4
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Re: [PATCH v2 2/4] PCI: pci-host-generic: Fix lookup of linux,pci-probe-only property
On Fri, Aug 14, 2015 at 05:19:17PM +0100, Marc Zyngier wrote:
When pci-host-generic looks for the probe-only property, it seems
to trust the DT to be correctly written, and assumes that there
is a parameter to the property.
Unfortunately, this is not always the case, and some firmware expose
this property naked. The driver ends up making a decision based on
whatever the property pointer points to, which is likely to be junk.
Switch to the common of_pci.c implementation that doesn't suffer
from this problem.
Signed-off-by: Marc Zyngier marc.zyng...@arm.com
---
drivers/pci/host/pci-host-generic.c | 9 +
1 file changed, 1 insertion(+), 8 deletions(-)
diff --git a/drivers/pci/host/pci-host-generic.c
b/drivers/pci/host/pci-host-generic.c
index 265dd25..545ff4e 100644
--- a/drivers/pci/host/pci-host-generic.c
+++ b/drivers/pci/host/pci-host-generic.c
@@ -210,7 +210,6 @@ static int gen_pci_probe(struct platform_device *pdev)
int err;
const char *type;
const struct of_device_id *of_id;
- const int *prop;
struct device *dev = pdev-dev;
struct device_node *np = dev-of_node;
struct gen_pci *pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
@@ -225,13 +224,7 @@ static int gen_pci_probe(struct platform_device *pdev)
return -EINVAL;
}
- prop = of_get_property(of_chosen, linux,pci-probe-only, NULL);
- if (prop) {
- if (*prop)
- pci_add_flags(PCI_PROBE_ONLY);
- else
- pci_clear_flags(PCI_PROBE_ONLY);
- }
+ of_pci_check_probe_only(of_chosen);
Do we need support for pci-probe-only in pci-host-generic at all?
You're removing the use in amd-overdrive.dts, and there are no other
DTs in the kernel tree that mention it.
If we can live without it, that would be nice. It seems like a relic from
days when we couldn't reliably assign resources. (I'm not saying we can do
that reliably even today, but I'd rather make it reliable than turn it
off.)
of_id = of_match_node(gen_pci_of_match, np);
pci-cfg.ops = of_id-data;
--
2.1.4
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Re: [PATCH v2 2/4] PCI: pci-host-generic: Fix lookup of linux,pci-probe-only property
On 14.08.2015, at 09:43, Will Deacon will.dea...@arm.com wrote:
On Fri, Aug 14, 2015 at 05:40:51PM +0100, Bjorn Helgaas wrote:
On Fri, Aug 14, 2015 at 05:19:17PM +0100, Marc Zyngier wrote:
When pci-host-generic looks for the probe-only property, it seems
to trust the DT to be correctly written, and assumes that there
is a parameter to the property.
Unfortunately, this is not always the case, and some firmware expose
this property naked. The driver ends up making a decision based on
whatever the property pointer points to, which is likely to be junk.
Switch to the common of_pci.c implementation that doesn't suffer
from this problem.
Signed-off-by: Marc Zyngier marc.zyng...@arm.com
---
drivers/pci/host/pci-host-generic.c | 9 +
1 file changed, 1 insertion(+), 8 deletions(-)
diff --git a/drivers/pci/host/pci-host-generic.c
b/drivers/pci/host/pci-host-generic.c
index 265dd25..545ff4e 100644
--- a/drivers/pci/host/pci-host-generic.c
+++ b/drivers/pci/host/pci-host-generic.c
@@ -210,7 +210,6 @@ static int gen_pci_probe(struct platform_device *pdev)
int err;
const char *type;
const struct of_device_id *of_id;
- const int *prop;
struct device *dev = pdev-dev;
struct device_node *np = dev-of_node;
struct gen_pci *pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
@@ -225,13 +224,7 @@ static int gen_pci_probe(struct platform_device *pdev)
return -EINVAL;
}
- prop = of_get_property(of_chosen, linux,pci-probe-only, NULL);
- if (prop) {
- if (*prop)
- pci_add_flags(PCI_PROBE_ONLY);
- else
- pci_clear_flags(PCI_PROBE_ONLY);
- }
+ of_pci_check_probe_only(of_chosen);
Do we need support for pci-probe-only in pci-host-generic at all?
You're removing the use in amd-overdrive.dts, and there are no other
DTs in the kernel tree that mention it.
If we can live without it, that would be nice. It seems like a relic from
days when we couldn't reliably assign resources. (I'm not saying we can do
that reliably even today, but I'd rather make it reliable than turn it
off.)
Kvmtool certainly uses it (and generates its own DT, hence why you don't
see it in mainline). Not sure about qemu, though.
QEMU definitely doesn't do proble-only. Is this driver used on real PPC
machines too? In that case you also won't see the dt, because it comes with the
hardware ;).
Alex
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Re: [PATCH v2 2/4] PCI: pci-host-generic: Fix lookup of linux,pci-probe-only property
On Fri, Aug 14, 2015 at 05:40:51PM +0100, Bjorn Helgaas wrote:
On Fri, Aug 14, 2015 at 05:19:17PM +0100, Marc Zyngier wrote:
When pci-host-generic looks for the probe-only property, it seems
to trust the DT to be correctly written, and assumes that there
is a parameter to the property.
Unfortunately, this is not always the case, and some firmware expose
this property naked. The driver ends up making a decision based on
whatever the property pointer points to, which is likely to be junk.
Switch to the common of_pci.c implementation that doesn't suffer
from this problem.
Signed-off-by: Marc Zyngier marc.zyng...@arm.com
---
drivers/pci/host/pci-host-generic.c | 9 +
1 file changed, 1 insertion(+), 8 deletions(-)
diff --git a/drivers/pci/host/pci-host-generic.c
b/drivers/pci/host/pci-host-generic.c
index 265dd25..545ff4e 100644
--- a/drivers/pci/host/pci-host-generic.c
+++ b/drivers/pci/host/pci-host-generic.c
@@ -210,7 +210,6 @@ static int gen_pci_probe(struct platform_device *pdev)
int err;
const char *type;
const struct of_device_id *of_id;
- const int *prop;
struct device *dev = pdev-dev;
struct device_node *np = dev-of_node;
struct gen_pci *pci = devm_kzalloc(dev, sizeof(*pci), GFP_KERNEL);
@@ -225,13 +224,7 @@ static int gen_pci_probe(struct platform_device *pdev)
return -EINVAL;
}
- prop = of_get_property(of_chosen, linux,pci-probe-only, NULL);
- if (prop) {
- if (*prop)
- pci_add_flags(PCI_PROBE_ONLY);
- else
- pci_clear_flags(PCI_PROBE_ONLY);
- }
+ of_pci_check_probe_only(of_chosen);
Do we need support for pci-probe-only in pci-host-generic at all?
You're removing the use in amd-overdrive.dts, and there are no other
DTs in the kernel tree that mention it.
If we can live without it, that would be nice. It seems like a relic from
days when we couldn't reliably assign resources. (I'm not saying we can do
that reliably even today, but I'd rather make it reliable than turn it
off.)
Kvmtool certainly uses it (and generates its own DT, hence why you don't
see it in mainline). Not sure about qemu, though.
Will
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