2015-11-17 15:00:40

by Robin Murphy

[permalink] [raw]
Subject: Re: [PATCH V5 8/9] PCI: OF: Move of_pci_dma_configure() to pci_dma_configure()

Hi Suravee,

On 28/10/15 22:50, Suravee Suthikulpanit wrote:
> This patch move of_pci_dma_configure() to a more generic
> pci_dma_configure(), which can be extended by non-OF code (e.g. ACPI).
>
> This has no functional change.

Unfortunately, it appears that it does...

> Signed-off-by: Suravee Suthikulpanit <[email protected]>
> Acked-by: Rob Herring <[email protected]>
> Acked-by: Bjorn Helgaas <[email protected]>
> Reviewed-by: Hanjun Guo <[email protected]>
> CC: Rafael J. Wysocki <[email protected]>
> ---
> drivers/of/of_pci.c | 19 -------------------
> drivers/pci/probe.c | 23 +++++++++++++++++++++--
> include/linux/of_pci.h | 3 ---
> 3 files changed, 21 insertions(+), 24 deletions(-)
>
> diff --git a/drivers/of/of_pci.c b/drivers/of/of_pci.c
> index a2f510c..b66ee4e 100644
> --- a/drivers/of/of_pci.c
> +++ b/drivers/of/of_pci.c
> @@ -117,25 +117,6 @@ int of_get_pci_domain_nr(struct device_node *node)
> }
> EXPORT_SYMBOL_GPL(of_get_pci_domain_nr);
>
> -/**
> - * of_pci_dma_configure - Setup DMA configuration
> - * @dev: ptr to pci_dev struct of the PCI device
> - *
> - * Function to update PCI devices's DMA configuration using the same
> - * info from the OF node of host bridge's parent (if any).
> - */
> -void of_pci_dma_configure(struct pci_dev *pci_dev)
> -{
> - struct device *dev = &pci_dev->dev;
> - struct device *bridge = pci_get_host_bridge_device(pci_dev);
> -
> - if (bridge->parent)
> - of_dma_configure(dev, bridge->parent->of_node);
> -
> - pci_put_host_bridge_device(bridge);
> -}
> -EXPORT_SYMBOL_GPL(of_pci_dma_configure);
> -
> #if defined(CONFIG_OF_ADDRESS)
> /**
> * of_pci_get_host_bridge_resources - Parse PCI host bridge resources from DT
> diff --git a/drivers/pci/probe.c b/drivers/pci/probe.c
> index 8361d27..31e3eef 100644
> --- a/drivers/pci/probe.c
> +++ b/drivers/pci/probe.c
> @@ -6,7 +6,7 @@
> #include <linux/delay.h>
> #include <linux/init.h>
> #include <linux/pci.h>
> -#include <linux/of_pci.h>
> +#include <linux/of_device.h>
> #include <linux/pci_hotplug.h>
> #include <linux/slab.h>
> #include <linux/module.h>
> @@ -1633,6 +1633,25 @@ static void pci_set_msi_domain(struct pci_dev *dev)
> dev_get_msi_domain(&dev->bus->dev));
> }
>
> +/**
> + * pci_dma_configure - Setup DMA configuration
> + * @dev: ptr to pci_dev struct of the PCI device
> + *
> + * Function to update PCI devices's DMA configuration using the same
> + * info from the OF node of host bridge's parent (if any).
> + */
> +static void pci_dma_configure(struct pci_dev *dev)
> +{
> + struct device *bridge = pci_get_host_bridge_device(dev);
> +
> + if (IS_ENABLED(CONFIG_OF) && dev->dev.of_node) {

Previously I was seeing of_dma_configure, and thus of_iommu_configure,
called for every PCI device on Juno. The check above now prevents this
happening, since the PCI devices are probed directly from the bus and
don't have OF nodes of their own. They now get left in some
half-configured state where arch_setup_dma_ops isn't called either.

Should this be checking bridge->parent->of_node rather than
dev->dev.of_node (which seems to work), or am I missing something?

Sorry I don't really have the bandwidth to look into this in detail
myself, right now I'm just trying to get my magic hacks rebased ;)

Robin.

> + if (bridge->parent)
> + of_dma_configure(&dev->dev, bridge->parent->of_node);
> + }
> +
> + pci_put_host_bridge_device(bridge);
> +}
> +
> void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
> {
> int ret;
> @@ -1646,7 +1665,7 @@ void pci_device_add(struct pci_dev *dev, struct pci_bus *bus)
> dev->dev.dma_mask = &dev->dma_mask;
> dev->dev.dma_parms = &dev->dma_parms;
> dev->dev.coherent_dma_mask = 0xffffffffull;
> - of_pci_dma_configure(dev);
> + pci_dma_configure(dev);
>
> pci_set_dma_max_seg_size(dev, 65536);
> pci_set_dma_seg_boundary(dev, 0xffffffff);
> diff --git a/include/linux/of_pci.h b/include/linux/of_pci.h
> index 29fd3fe..ce0e5ab 100644
> --- a/include/linux/of_pci.h
> +++ b/include/linux/of_pci.h
> @@ -16,7 +16,6 @@ int of_pci_get_devfn(struct device_node *np);
> int of_irq_parse_and_map_pci(const struct pci_dev *dev, u8 slot, u8 pin);
> int of_pci_parse_bus_range(struct device_node *node, struct resource *res);
> int of_get_pci_domain_nr(struct device_node *node);
> -void of_pci_dma_configure(struct pci_dev *pci_dev);
> #else
> static inline int of_irq_parse_pci(const struct pci_dev *pdev, struct of_phandle_args *out_irq)
> {
> @@ -51,8 +50,6 @@ of_get_pci_domain_nr(struct device_node *node)
> {
> return -1;
> }
> -
> -static inline void of_pci_dma_configure(struct pci_dev *pci_dev) { }
> #endif
>
> #if defined(CONFIG_OF_ADDRESS)
>


2015-11-18 12:00:38

by Robin Murphy

[permalink] [raw]
Subject: Re: [PATCH V5 8/9] PCI: OF: Move of_pci_dma_configure() to pci_dma_configure()

+Arnd

On 17/11/15 15:00, Robin Murphy wrote:
> Hi Suravee,
>
> On 28/10/15 22:50, Suravee Suthikulpanit wrote:
>> This patch move of_pci_dma_configure() to a more generic
>> pci_dma_configure(), which can be extended by non-OF code (e.g. ACPI).
>>
>> This has no functional change.
>
> Unfortunately, it appears that it does...
>
>> Signed-off-by: Suravee Suthikulpanit <[email protected]>
>> Acked-by: Rob Herring <[email protected]>
>> Acked-by: Bjorn Helgaas <[email protected]>
>> Reviewed-by: Hanjun Guo <[email protected]>
>> CC: Rafael J. Wysocki <[email protected]>
[...]
>> +/**
>> + * pci_dma_configure - Setup DMA configuration
>> + * @dev: ptr to pci_dev struct of the PCI device
>> + *
>> + * Function to update PCI devices's DMA configuration using the same
>> + * info from the OF node of host bridge's parent (if any).
>> + */
>> +static void pci_dma_configure(struct pci_dev *dev)
>> +{
>> + struct device *bridge = pci_get_host_bridge_device(dev);
>> +
>> + if (IS_ENABLED(CONFIG_OF) && dev->dev.of_node) {
>
> Previously I was seeing of_dma_configure, and thus of_iommu_configure,
> called for every PCI device on Juno. The check above now prevents this
> happening, since the PCI devices are probed directly from the bus and
> don't have OF nodes of their own. They now get left in some
> half-configured state where arch_setup_dma_ops isn't called either.

Just to follow up on that, Arnd's patch to tidy up dma_get_ops (now
queued[1]) makes this even worse, since preventing arch_setup_dma_ops
being called means the PCI devices now get the dummy DMA ops which leave
the drivers failing to probe at all, IOMMU hacks or not :(

Robin.

[1]:https://git.kernel.org/cgit/linux/kernel/git/arm64/linux.git/commit/?h=fixes/core&id=1dccb598df549d892b6450c261da54cdd7af44b4

> Should this be checking bridge->parent->of_node rather than
> dev->dev.of_node (which seems to work), or am I missing something?
>
> Sorry I don't really have the bandwidth to look into this in detail
> myself, right now I'm just trying to get my magic hacks rebased ;)
>
> Robin.
>
>> + if (bridge->parent)
>> + of_dma_configure(&dev->dev, bridge->parent->of_node);
>> + }
>> +
>> + pci_put_host_bridge_device(bridge);
>> +}

2015-11-18 12:42:35

by Arnd Bergmann

[permalink] [raw]
Subject: Re: [PATCH V5 8/9] PCI: OF: Move of_pci_dma_configure() to pci_dma_configure()

On Wednesday 18 November 2015 12:00:32 Robin Murphy wrote:
> On 17/11/15 15:00, Robin Murphy wrote:
> > On 28/10/15 22:50, Suravee Suthikulpanit wrote:
> >> Signed-off-by: Suravee Suthikulpanit <[email protected]>
> >> Acked-by: Rob Herring <[email protected]>
> >> Acked-by: Bjorn Helgaas <[email protected]>
> >> Reviewed-by: Hanjun Guo <[email protected]>
> >> CC: Rafael J. Wysocki <[email protected]>
> [...]
> >> +/**
> >> + * pci_dma_configure - Setup DMA configuration
> >> + * @dev: ptr to pci_dev struct of the PCI device
> >> + *
> >> + * Function to update PCI devices's DMA configuration using the same
> >> + * info from the OF node of host bridge's parent (if any).
> >> + */
> >> +static void pci_dma_configure(struct pci_dev *dev)
> >> +{
> >> + struct device *bridge = pci_get_host_bridge_device(dev);
> >> +
> >> + if (IS_ENABLED(CONFIG_OF) && dev->dev.of_node) {
> >
> > Previously I was seeing of_dma_configure, and thus of_iommu_configure,
> > called for every PCI device on Juno. The check above now prevents this
> > happening, since the PCI devices are probed directly from the bus and
> > don't have OF nodes of their own. They now get left in some
> > half-configured state where arch_setup_dma_ops isn't called either.
>
> Just to follow up on that, Arnd's patch to tidy up dma_get_ops (now
> queued[1]) makes this even worse, since preventing arch_setup_dma_ops
> being called means the PCI devices now get the dummy DMA ops which leave
> the drivers failing to probe at all, IOMMU hacks or not

Ok, glad we found that with my patch then. We really have to
configure the DMA (offset/size/coherency/iommu) for all devices that might
be masters, otherwise things can randomly go wrong.

ARnd

2015-11-18 15:10:54

by Suthikulpanit, Suravee

[permalink] [raw]
Subject: Re: [PATCH V5 8/9] PCI: OF: Move of_pci_dma_configure() to pci_dma_configure()

On 11/18/2015 6:41 AM, Arnd Bergmann wrote:
> On Wednesday 18 November 2015 12:00:32 Robin Murphy wrote:
>> On 17/11/15 15:00, Robin Murphy wrote:
>>> On 28/10/15 22:50, Suravee Suthikulpanit wrote:
>>>> Signed-off-by: Suravee Suthikulpanit <[email protected]>
>>>> Acked-by: Rob Herring <[email protected]>
>>>> Acked-by: Bjorn Helgaas <[email protected]>
>>>> Reviewed-by: Hanjun Guo <[email protected]>
>>>> CC: Rafael J. Wysocki <[email protected]>
>> [...]
>>>> +/**
>>>> + * pci_dma_configure - Setup DMA configuration
>>>> + * @dev: ptr to pci_dev struct of the PCI device
>>>> + *
>>>> + * Function to update PCI devices's DMA configuration using the same
>>>> + * info from the OF node of host bridge's parent (if any).
>>>> + */
>>>> +static void pci_dma_configure(struct pci_dev *dev)
>>>> +{
>>>> + struct device *bridge = pci_get_host_bridge_device(dev);
>>>> +
>>>> + if (IS_ENABLED(CONFIG_OF) && dev->dev.of_node) {
>>>
>>> Previously I was seeing of_dma_configure, and thus of_iommu_configure,
>>> called for every PCI device on Juno. The check above now prevents this
>>> happening, since the PCI devices are probed directly from the bus and
>>> don't have OF nodes of their own. They now get left in some
>>> half-configured state where arch_setup_dma_ops isn't called either.
>>
>> Just to follow up on that, Arnd's patch to tidy up dma_get_ops (now
>> queued[1]) makes this even worse, since preventing arch_setup_dma_ops
>> being called means the PCI devices now get the dummy DMA ops which leave
>> the drivers failing to probe at all, IOMMU hacks or not
>
> Ok, glad we found that with my patch then. We really have to
> configure the DMA (offset/size/coherency/iommu) for all devices that might
> be masters, otherwise things can randomly go wrong.
>
> ARnd
>
I'm double checking this and will get back ASAP.

Suravee

2015-11-18 16:55:12

by Suthikulpanit, Suravee

[permalink] [raw]
Subject: Re: [PATCH V5 8/9] PCI: OF: Move of_pci_dma_configure() to pci_dma_configure()

Hi All,

On 11/18/2015 6:41 AM, Arnd Bergmann wrote:
> On Wednesday 18 November 2015 12:00:32 Robin Murphy wrote:
>> On 17/11/15 15:00, Robin Murphy wrote:
>>> On 28/10/15 22:50, Suravee Suthikulpanit wrote:
>>>> Signed-off-by: Suravee Suthikulpanit <[email protected]>
>>>> Acked-by: Rob Herring <[email protected]>
>>>> Acked-by: Bjorn Helgaas <[email protected]>
>>>> Reviewed-by: Hanjun Guo <[email protected]>
>>>> CC: Rafael J. Wysocki <[email protected]>
>> [...]
>>>> +/**
>>>> + * pci_dma_configure - Setup DMA configuration
>>>> + * @dev: ptr to pci_dev struct of the PCI device
>>>> + *
>>>> + * Function to update PCI devices's DMA configuration using the same
>>>> + * info from the OF node of host bridge's parent (if any).
>>>> + */
>>>> +static void pci_dma_configure(struct pci_dev *dev)
>>>> +{
>>>> + struct device *bridge = pci_get_host_bridge_device(dev);
>>>> +
>>>> + if (IS_ENABLED(CONFIG_OF) && dev->dev.of_node) {
>>>
>>> Previously I was seeing of_dma_configure, and thus of_iommu_configure,
>>> called for every PCI device on Juno. The check above now prevents this
>>> happening, since the PCI devices are probed directly from the bus and
>>> don't have OF nodes of their own. They now get left in some
>>> half-configured state where arch_setup_dma_ops isn't called either.
>>
>> Just to follow up on that, Arnd's patch to tidy up dma_get_ops (now
>> queued[1]) makes this even worse, since preventing arch_setup_dma_ops
>> being called means the PCI devices now get the dummy DMA ops which leave
>> the drivers failing to probe at all, IOMMU hacks or not
>
> Ok, glad we found that with my patch then. We really have to
> configure the DMA (offset/size/coherency/iommu) for all devices that might
> be masters, otherwise things can randomly go wrong.
>
> ARnd

Robin is correct. Thanks for catching the bug. Rafael, do you want me to
submit just the fixed-up patch on top of what we had earlier. Or do you
want a new revision (V6)?

Thanks,
Suravee

2015-11-18 20:55:24

by Rafael J. Wysocki

[permalink] [raw]
Subject: Re: [PATCH V5 8/9] PCI: OF: Move of_pci_dma_configure() to pci_dma_configure()

On Wednesday, November 18, 2015 10:54:59 AM Suravee Suthikulanit wrote:
> Hi All,
>
> On 11/18/2015 6:41 AM, Arnd Bergmann wrote:
> > On Wednesday 18 November 2015 12:00:32 Robin Murphy wrote:
> >> On 17/11/15 15:00, Robin Murphy wrote:
> >>> On 28/10/15 22:50, Suravee Suthikulpanit wrote:
> >>>> Signed-off-by: Suravee Suthikulpanit <[email protected]>
> >>>> Acked-by: Rob Herring <[email protected]>
> >>>> Acked-by: Bjorn Helgaas <[email protected]>
> >>>> Reviewed-by: Hanjun Guo <[email protected]>
> >>>> CC: Rafael J. Wysocki <[email protected]>
> >> [...]
> >>>> +/**
> >>>> + * pci_dma_configure - Setup DMA configuration
> >>>> + * @dev: ptr to pci_dev struct of the PCI device
> >>>> + *
> >>>> + * Function to update PCI devices's DMA configuration using the same
> >>>> + * info from the OF node of host bridge's parent (if any).
> >>>> + */
> >>>> +static void pci_dma_configure(struct pci_dev *dev)
> >>>> +{
> >>>> + struct device *bridge = pci_get_host_bridge_device(dev);
> >>>> +
> >>>> + if (IS_ENABLED(CONFIG_OF) && dev->dev.of_node) {
> >>>
> >>> Previously I was seeing of_dma_configure, and thus of_iommu_configure,
> >>> called for every PCI device on Juno. The check above now prevents this
> >>> happening, since the PCI devices are probed directly from the bus and
> >>> don't have OF nodes of their own. They now get left in some
> >>> half-configured state where arch_setup_dma_ops isn't called either.
> >>
> >> Just to follow up on that, Arnd's patch to tidy up dma_get_ops (now
> >> queued[1]) makes this even worse, since preventing arch_setup_dma_ops
> >> being called means the PCI devices now get the dummy DMA ops which leave
> >> the drivers failing to probe at all, IOMMU hacks or not
> >
> > Ok, glad we found that with my patch then. We really have to
> > configure the DMA (offset/size/coherency/iommu) for all devices that might
> > be masters, otherwise things can randomly go wrong.
> >
> > ARnd
>
> Robin is correct. Thanks for catching the bug. Rafael, do you want me to
> submit just the fixed-up patch on top of what we had earlier. Or do you
> want a new revision (V6)?

This is in 4.4-rc1, right? So new revisions surely won't work, will they?

Thanks,
Rafael