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Groups > linux.kernel > #1550161
| From | Nikita Yushchenko <nikita.yoush@cogentembedded.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH 1/2] arm64: dma_mapping: allow PCI host driver to limit DMA mask |
| Date | 2017-01-03 21:40 +0100 |
| Message-ID | <sVE2e-37A-15@gated-at.bofh.it> (permalink) |
| References | <sTPO9-2Zl-3@gated-at.bofh.it> <sVCjL-1Wi-15@gated-at.bofh.it> <sVCD8-2iN-33@gated-at.bofh.it> <sVDIR-30E-5@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
>>>> diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
>>>> index 290a84f..49645277 100644
>>>> --- a/arch/arm64/mm/dma-mapping.c
>>>> +++ b/arch/arm64/mm/dma-mapping.c
>>>> @@ -28,6 +28,7 @@
>>>> #include <linux/dma-contiguous.h>
>>>> #include <linux/vmalloc.h>
>>>> #include <linux/swiotlb.h>
>>>> +#include <linux/pci.h>
>>>>
>>>> #include <asm/cacheflush.h>
>>>>
>>>> @@ -347,6 +348,16 @@ static int __swiotlb_get_sgtable(struct device *dev, struct sg_table *sgt,
>>>>
>>>> static int __swiotlb_dma_supported(struct device *hwdev, u64 mask)
>>>> {
>>>> +#ifdef CONFIG_PCI
>>>> + if (dev_is_pci(hwdev)) {
>>>> + struct pci_dev *pdev = to_pci_dev(hwdev);
>>>> + struct pci_host_bridge *br = pci_find_host_bridge(pdev->bus);
>>>> +
>>>> + if (br->dev.dma_mask && (*br->dev.dma_mask) &&
>>>> + (mask & (*br->dev.dma_mask)) != mask)
>>>> + return 0;
>>>> + }
>>>> +#endif
>>>
>>> Hmm, but this makes it look like the problem is both arm64 and swiotlb
>>> specific, when in reality it's not. Perhaps another hack you could try
>>> would be to register a PCI bus notifier in the host bridge looking for
>>> BUS_NOTIFY_BIND_DRIVER, then you could proxy the DMA ops for each child
>>> device before the driver has probed, but adding a dma_set_mask callback
>>> to limit the mask to what you need?
>>
>> This is what Renesas BSP tries to do and it does not work.
>>
>> BUS_NOTIFY_BIND_DRIVER arrives after driver's probe routine exits, but
>> i/o can be started before that.
>
> Hm. This is strange statement:
> really_probe
> |->driver_sysfs_add
> |-> blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
> BUS_NOTIFY_BIND_DRIVER, dev);
> ...
> |- ret = drv->probe(dev);
> ...
> |- driver_bound(dev);
> |- blocking_notifier_call_chain(&dev->bus->p->bus_notifier,
> BUS_NOTIFY_BOUND_DRIVER, dev);
>
> Am I missing smth?
I misinterpreted your message, sorry.
BSP attaches to BUS_NOTIFY_BOUND_DRIVER, not to BUS_NOTIFY_BIND_DRIVER,
and simply overwrites device's dma_mask there. You are suggesting
something completely different.
I'll check if your approach is practical.
Currently powerpc architecture has one more approach implemented, they
use pci_controller structure provided by host bridge driver, and that
has a set_dma_mask() hook. Maybe extending this beyond powerpc could be
a good idea. However, that will require changing quite a few host bridge
drivers, without any gain for most of those...
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[PATCH 1/2] arm64: dma_mapping: allow PCI host driver to limit DMA mask Nikita Yushchenko <nikita.yoush@cogentembedded.com> - 2016-12-29 21:50 +0100
[PATCH 2/2] rcar-pcie: set host bridge's DMA mask Nikita Yushchenko <nikita.yoush@cogentembedded.com> - 2016-12-29 21:50 +0100
Re: [PATCH 1/2] arm64: dma_mapping: allow PCI host driver to limit DMA mask Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> - 2016-12-30 10:50 +0100
Re: [PATCH 1/2] arm64: dma_mapping: allow PCI host driver to limit DMA mask Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> - 2016-12-30 11:10 +0100
Re: [PATCH 1/2] arm64: dma_mapping: allow PCI host driver to limit DMA mask Will Deacon <will.deacon@arm.com> - 2017-01-03 19:50 +0100
Re: [PATCH 1/2] arm64: dma_mapping: allow PCI host driver to limit DMA mask Nikita Yushchenko <nikita.yoush@cogentembedded.com> - 2017-01-03 20:10 +0100
Re: [PATCH 1/2] arm64: dma_mapping: allow PCI host driver to limit DMA mask Grygorii Strashko <grygorii.strashko@ti.com> - 2017-01-03 21:20 +0100
Re: [PATCH 1/2] arm64: dma_mapping: allow PCI host driver to limit DMA mask Nikita Yushchenko <nikita.yoush@cogentembedded.com> - 2017-01-03 21:40 +0100
Re: [PATCH 1/2] arm64: dma_mapping: allow PCI host driver to limit DMA mask Arnd Bergmann <arnd@arndb.de> - 2017-01-04 00:20 +0100
Re: [PATCH 1/2] arm64: dma_mapping: allow PCI host driver to limit DMA mask Nikita Yushchenko <nikita.yoush@cogentembedded.com> - 2017-01-04 07:40 +0100
Re: [PATCH 1/2] arm64: dma_mapping: allow PCI host driver to limit DMA mask Arnd Bergmann <arnd@arndb.de> - 2017-01-04 14:30 +0100
Re: [PATCH 1/2] arm64: dma_mapping: allow PCI host driver to limit DMA mask Nikita Yushchenko <nikita.yoush@cogentembedded.com> - 2017-01-04 15:40 +0100
Re: [PATCH 1/2] arm64: dma_mapping: allow PCI host driver to limit DMA mask Arnd Bergmann <arnd@arndb.de> - 2017-01-04 15:50 +0100
Re: [PATCH 1/2] arm64: dma_mapping: allow PCI host driver to limit DMA mask Nikita Yushchenko <nikita.yoush@cogentembedded.com> - 2017-01-04 16:40 +0100
Re: [PATCH 1/2] arm64: dma_mapping: allow PCI host driver to limit DMA mask Arnd Bergmann <arnd@arndb.de> - 2017-01-06 12:20 +0100
Re: [PATCH 1/2] arm64: dma_mapping: allow PCI host driver to limit DMA mask Nikita Yushchenko <nikita.yoush@cogentembedded.com> - 2017-01-06 14:50 +0100
[PATCH] arm64: do not set dma masks that device connection can't handle Nikita Yushchenko <nikita.yoush@cogentembedded.com> - 2017-01-06 15:40 +0100
[PATCH] arm64: do not set dma masks that device connection can't handle Nikita Yushchenko <nikita.yoush@cogentembedded.com> - 2017-01-06 16:00 +0100
Re: [PATCH] arm64: do not set dma masks that device connection can't handle Sergei Shtylyov <sergei.shtylyov@cogentembedded.com> - 2017-01-08 08:20 +0100
Re: [PATCH] arm64: do not set dma masks that device connection can't handle Nikita Yushchenko <nikita.yoush@cogentembedded.com> - 2017-01-09 08:00 +0100
Re: [PATCH 1/2] arm64: dma_mapping: allow PCI host driver to limit DMA mask Arnd Bergmann <arnd@linaro.org> - 2017-01-09 15:10 +0100
Re: [PATCH 1/2] arm64: dma_mapping: allow PCI host driver to limit DMA mask Nikita Yushchenko <nikita.yoush@cogentembedded.com> - 2017-01-09 21:40 +0100
Re: [PATCH 1/2] arm64: dma_mapping: allow PCI host driver to limit DMA mask Christoph Hellwig <hch@lst.de> - 2017-01-09 22:00 +0100
NVMe vs DMA addressing limitations Nikita Yushchenko <nikita.yoush@cogentembedded.com> - 2017-01-10 07:50 +0100
Re: NVMe vs DMA addressing limitations Christoph Hellwig <hch@lst.de> - 2017-01-10 08:10 +0100
Re: NVMe vs DMA addressing limitations Nikita Yushchenko <nikita.yoush@cogentembedded.com> - 2017-01-10 08:40 +0100
Re: NVMe vs DMA addressing limitations Arnd Bergmann <arnd@linaro.org> - 2017-01-10 12:10 +0100
Re: NVMe vs DMA addressing limitations Christoph Hellwig <hch@lst.de> - 2017-01-10 15:50 +0100
Re: NVMe vs DMA addressing limitations Arnd Bergmann <arnd@linaro.org> - 2017-01-10 16:10 +0100
Re: NVMe vs DMA addressing limitations Sagi Grimberg <sagi@grimberg.me> - 2017-01-12 11:10 +0100
Re: NVMe vs DMA addressing limitations Arnd Bergmann <arnd@linaro.org> - 2017-01-12 13:00 +0100
Re: NVMe vs DMA addressing limitations Christoph Hellwig <hch@lst.de> - 2017-01-12 14:20 +0100
Re: NVMe vs DMA addressing limitations Arnd Bergmann <arnd@linaro.org> - 2017-01-10 12:00 +0100
Re: [PATCH 1/2] arm64: dma_mapping: allow PCI host driver to limit DMA mask Arnd Bergmann <arnd@linaro.org> - 2017-01-10 11:50 +0100
Re: [PATCH 1/2] arm64: dma_mapping: allow PCI host driver to limit DMA mask Christoph Hellwig <hch@lst.de> - 2017-01-10 15:50 +0100
Re: [PATCH 1/2] arm64: dma_mapping: allow PCI host driver to limit DMA mask Arnd Bergmann <arnd@linaro.org> - 2017-01-10 16:10 +0100
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