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Groups > linux.kernel > #1378054
| From | Tomasz Nowicki <tn@semihalf.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH V4 4/7] ARM64, ACPI, PCI: I/O Remapping Table (IORT) initial support. |
| Date | 2016-04-13 17:40 +0200 |
| Message-ID | <rnv3A-3mt-7@gated-at.bofh.it> (permalink) |
| References | <rk8wy-tQ-3@gated-at.bofh.it> <rk8wy-tQ-21@gated-at.bofh.it> <rnuTT-3hb-5@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On 13.04.2016 17:23, Marc Zyngier wrote:
> On 04/04/16 09:52, Tomasz Nowicki wrote:
>> IORT shows representation of IO topology for ARM based systems.
>> It describes how various components are connected together on
>> parent-child basis e.g. PCI RC -> SMMU -> ITS. Also see IORT spec.
>>
>> Initial support allows to:
>> - register ITS MSI chip along with ITS translation ID and domain token
>> - deregister ITS MSI chip based on ITS translation ID
>> - find registered domain token based on ITS translation ID
>> - map MSI RID based on PCI device and requester ID
>> - find domain token based on PCI device and requester ID
>>
>> To: Rafael J. Wysocki <rjw@rjwysocki.net>
>> Signed-off-by: Tomasz Nowicki <tn@semihalf.com>
>> ---
>> drivers/acpi/Kconfig | 3 +
>> drivers/acpi/Makefile | 1 +
>> drivers/acpi/iort.c | 335 ++++++++++++++++++++++++++++++++++++++++++++++++
>> drivers/irqchip/Kconfig | 1 +
>> include/linux/iort.h | 31 +++++
>> 5 files changed, 371 insertions(+)
>> create mode 100644 drivers/acpi/iort.c
>> create mode 100644 include/linux/iort.h
>>
>
> [...]
>
>> +static acpi_status
>> +iort_find_dev_callback(struct acpi_iort_node *node, void *context)
>> +{
>> + struct acpi_iort_root_complex *pci_rc;
>> + struct device *dev = context;
>> + struct pci_bus *bus;
>> +
>> + switch (node->type) {
>> + case ACPI_IORT_NODE_PCI_ROOT_COMPLEX:
>> + bus = to_pci_bus(dev);
>> + pci_rc = (struct acpi_iort_root_complex *)node->node_data;
>> +
>> + /*
>> + * It is assumed that PCI segment numbers maps one-to-one
>> + * with root complexes. Each segment number can represent only
>> + * one root complex.
>> + */
>> + if (pci_rc->pci_segment_number == pci_domain_nr(bus))
>> + return AE_OK;
>
> What guarantees that this is ever valid? As far as I know, pci_domain_nr
> is completely arbitrary, and depends both on the probe order and the
> phase of the moon. If you want this to be reliable, you need to allocate
> the domain number from pci_segment_number.
>
> I must be missing something. Care to shed some light on this?
>
Sure. Please see:
http://infocenter.arm.com/help/topic/com.arm.doc.den0049a/DEN0049A_IO_Remapping_Table.pdf
3.1.1.5 PCI root complex node
PCI Segment number -> The PCI segment number, as in MCFG and as
returned by _SEG in the namespace.
So IORT spec states that pci_segment_number corresponds to the segment
number from MCFG table and _SEG method. Here is my patch which makes
sure pci_domain_nr(bus) is set properly:
https://lkml.org/lkml/2016/2/16/418
Tomasz
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[PATCH V4 0/7] Introduce ACPI world to ITS irqchip Tomasz Nowicki <tn@semihalf.com> - 2016-04-04 11:00 +0200
[PATCH V4 7/7] acpi, gicv3, its: Use MADT ITS subtable to do PCI/MSI domain initialization. Tomasz Nowicki <tn@semihalf.com> - 2016-04-04 11:00 +0200
[PATCH V4 2/7] irqchip, GICv3, ITS: Cleanup for ITS domain initialization. Tomasz Nowicki <tn@semihalf.com> - 2016-04-04 11:00 +0200
Re: [PATCH V4 2/7] irqchip, GICv3, ITS: Cleanup for ITS domain initialization. Marc Zyngier <marc.zyngier@arm.com> - 2016-04-13 16:20 +0200
[PATCH V4 5/7] irqchip, gicv3, its: Probe ITS in the ACPI way. Tomasz Nowicki <tn@semihalf.com> - 2016-04-04 11:00 +0200
Re: [PATCH V4 5/7] irqchip, gicv3, its: Probe ITS in the ACPI way. Marc Zyngier <marc.zyngier@arm.com> - 2016-04-14 11:10 +0200
[PATCH V4 3/7] irqchip, GICv3, ITS: Refator ITS DT init code to prepare for ACPI. Tomasz Nowicki <tn@semihalf.com> - 2016-04-04 11:00 +0200
Re: [PATCH V4 3/7] irqchip, GICv3, ITS: Refator ITS DT init code to prepare for ACPI. Tomasz Nowicki <tn@semihalf.com> - 2016-04-12 12:20 +0200
Re: [PATCH V4 3/7] irqchip, GICv3, ITS: Refator ITS DT init code to prepare for ACPI. Marc Zyngier <marc.zyngier@arm.com> - 2016-04-13 17:10 +0200
[PATCH V4 6/7] its, pci, msi: Factor out code that might be reused for ACPI. Tomasz Nowicki <tn@semihalf.com> - 2016-04-04 11:00 +0200
[PATCH V4 1/7] acpi, pci: Setup MSI domain on a per-devices basis. Tomasz Nowicki <tn@semihalf.com> - 2016-04-04 11:00 +0200
Re: [PATCH V4 1/7] acpi, pci: Setup MSI domain on a per-devices basis. Marc Zyngier <marc.zyngier@arm.com> - 2016-04-13 12:20 +0200
Re: [PATCH V4 1/7] acpi, pci: Setup MSI domain on a per-devices basis. Tomasz Nowicki <tn@semihalf.com> - 2016-04-13 12:50 +0200
[PATCH V4 4/7] ARM64, ACPI, PCI: I/O Remapping Table (IORT) initial support. Tomasz Nowicki <tn@semihalf.com> - 2016-04-04 11:00 +0200
Re: [PATCH V4 4/7] ARM64, ACPI, PCI: I/O Remapping Table (IORT) initial support. Marc Zyngier <marc.zyngier@arm.com> - 2016-04-13 17:30 +0200
Re: [PATCH V4 4/7] ARM64, ACPI, PCI: I/O Remapping Table (IORT) initial support. Tomasz Nowicki <tn@semihalf.com> - 2016-04-13 17:40 +0200
Re: [PATCH V4 4/7] ARM64, ACPI, PCI: I/O Remapping Table (IORT) initial support. Marc Zyngier <marc.zyngier@arm.com> - 2016-04-13 18:00 +0200
Re: [PATCH V4 4/7] ARM64, ACPI, PCI: I/O Remapping Table (IORT) initial support. Sinan Kaya <okaya@codeaurora.org> - 2016-04-13 23:20 +0200
Re: [PATCH V4 4/7] ARM64, ACPI, PCI: I/O Remapping Table (IORT) initial support. Tomasz Nowicki <tn@semihalf.com> - 2016-04-14 09:30 +0200
Re: [PATCH V4 4/7] ARM64, ACPI, PCI: I/O Remapping Table (IORT) initial support. Marc Zyngier <marc.zyngier@arm.com> - 2016-04-14 09:40 +0200
Re: [PATCH V4 4/7] ARM64, ACPI, PCI: I/O Remapping Table (IORT) initial support. okaya@codeaurora.org - 2016-04-14 13:40 +0200
Re: [PATCH V4 4/7] ARM64, ACPI, PCI: I/O Remapping Table (IORT) initial support. Marc Zyngier <marc.zyngier@arm.com> - 2016-04-14 13:50 +0200
Re: [PATCH V4 4/7] ARM64, ACPI, PCI: I/O Remapping Table (IORT) initial support. Tomasz Nowicki <tn@semihalf.com> - 2016-04-14 09:40 +0200
Re: [PATCH V4 4/7] ARM64, ACPI, PCI: I/O Remapping Table (IORT) initial support. Marc Zyngier <marc.zyngier@arm.com> - 2016-04-14 09:50 +0200
Re: [PATCH V4 0/7] Introduce ACPI world to ITS irqchip Tomasz Nowicki <tn@semihalf.com> - 2016-04-12 09:40 +0200
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