Messages in this thread | | | Subject | Re: [BUG] rockpro64: PCI BAR reassignment broken by commit 9d57e61bf723 ("of/pci: Add IORESOURCE_MEM_64 to resource flags for 64-bit memory addresses") | From | Robin Murphy <> | Date | Tue, 25 May 2021 18:14:42 +0100 |
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On 2021-05-25 17:59, Anand Moon wrote: > Hi Ard, > > On Tue, 25 May 2021 at 19:27, Ard Biesheuvel <ardb@kernel.org> wrote: >> >> On Tue, 25 May 2021 at 15:42, Punit Agrawal <punitagrawal@gmail.com> wrote: >>> >>> Hi Ard, >>> >>> Ard Biesheuvel <ardb@kernel.org> writes: >>> >>>> On Sun, 23 May 2021 at 13:06, Punit Agrawal <punitagrawal@gmail.com> wrote: >>>>> >>>>> Robin Murphy <robin.murphy@arm.com> writes: >>>>> >>>>>> [ +linux-pci for visibility ] >>>>>> >>>>>> On 2021-05-18 10:09, Alexandru Elisei wrote: >>>>>>> After doing a git bisect I was able to trace the following error when booting my >>>>>>> rockpro64 v2 (rk3399 SoC) with a PCIE NVME expansion card: >>>>>>> [..] >>>>>>> [ 0.305183] rockchip-pcie f8000000.pcie: host bridge /pcie@f8000000 ranges: >>>>>>> [ 0.305248] rockchip-pcie f8000000.pcie: MEM 0x00fa000000..0x00fbdfffff -> >>>>>>> 0x00fa000000 >>>>>>> [ 0.305285] rockchip-pcie f8000000.pcie: IO 0x00fbe00000..0x00fbefffff -> >>>>>>> 0x00fbe00000 >>>>>>> [ 0.306201] rockchip-pcie f8000000.pcie: supply vpcie1v8 not found, using dummy >>>>>>> regulator >>>>>>> [ 0.306334] rockchip-pcie f8000000.pcie: supply vpcie0v9 not found, using dummy >>>>>>> regulator >>>>>>> [ 0.373705] rockchip-pcie f8000000.pcie: PCI host bridge to bus 0000:00 >>>>>>> [ 0.373730] pci_bus 0000:00: root bus resource [bus 00-1f] >>>>>>> [ 0.373751] pci_bus 0000:00: root bus resource [mem 0xfa000000-0xfbdfffff 64bit] >>>>>>> [ 0.373777] pci_bus 0000:00: root bus resource [io 0x0000-0xfffff] (bus >>>>>>> address [0xfbe00000-0xfbefffff]) >>>>>>> [ 0.373839] pci 0000:00:00.0: [1d87:0100] type 01 class 0x060400 >>>>>>> [ 0.373973] pci 0000:00:00.0: supports D1 >>>>>>> [ 0.373992] pci 0000:00:00.0: PME# supported from D0 D1 D3hot >>>>>>> [ 0.378518] pci 0000:00:00.0: bridge configuration invalid ([bus 00-00]), >>>>>>> reconfiguring >>>>>>> [ 0.378765] pci 0000:01:00.0: [144d:a808] type 00 class 0x010802 >>>>>>> [ 0.378869] pci 0000:01:00.0: reg 0x10: [mem 0x00000000-0x00003fff 64bit] >>>>>>> [ 0.379051] pci 0000:01:00.0: Max Payload Size set to 256 (was 128, max 256) >>>>>>> [ 0.379661] pci 0000:01:00.0: 8.000 Gb/s available PCIe bandwidth, limited by >>>>>>> 2.5 GT/s PCIe x4 link at 0000:00:00.0 (capable of 31.504 Gb/s with 8.0 GT/s PCIe >>>>>>> x4 link) >>>>>>> [ 0.393269] pci_bus 0000:01: busn_res: [bus 01-1f] end is updated to 01 >>>>>>> [ 0.393311] pci 0000:00:00.0: BAR 14: no space for [mem size 0x00100000] >>>>>>> [ 0.393333] pci 0000:00:00.0: BAR 14: failed to assign [mem size 0x00100000] >>>>>>> [ 0.393356] pci 0000:01:00.0: BAR 0: no space for [mem size 0x00004000 64bit] >>>>>>> [ 0.393375] pci 0000:01:00.0: BAR 0: failed to assign [mem size 0x00004000 64bit] >>>>>>> [ 0.393397] pci 0000:00:00.0: PCI bridge to [bus 01] >>>>>>> [ 0.393839] pcieport 0000:00:00.0: PME: Signaling with IRQ 78 >>>>>>> [ 0.394165] pcieport 0000:00:00.0: AER: enabled with IRQ 78 >>>>>>> [..] >>>>>>> to the commit 9d57e61bf723 ("of/pci: Add IORESOURCE_MEM_64 to >>>>>>> resource flags for >>>>>>> 64-bit memory addresses"). >>>>>> >>>>>> FWFW, my hunch is that the host bridge advertising no 32-bit memory >>>>>> resource, only only a single 64-bit non-prefetchable one (even though >>>>>> it's entirely below 4GB) might be a bit weird and tripping something >>>>>> up in the resource assignment code. It certainly seems like the thing >>>>>> most directly related to the offending commit. >>>>>> >>>>>> I'd be tempted to try fiddling with that in the DT (i.e. changing >>>>>> 0x83000000 to 0x82000000 in the PCIe node's "ranges" property) to see >>>>>> if it makes any difference. Note that even if it helps, though, I >>>>>> don't know whether that's the correct fix or just a bodge around a >>>>>> corner-case bug somewhere in the resource code. >>>>> >>>>> From digging into this further the failure seems to be due to a mismatch >>>>> of flags when allocating resources in pci_bus_alloc_from_region() - >>>>> >>>>> if ((res->flags ^ r->flags) & type_mask) >>>>> continue; >>>>> >>>>> Though I am also not sure why the failure is only being reported on >>>>> RK3399 - does a single 64-bit window have anything to do with it? >>>>> >>>> >>>> The NVMe in the example exposes a single 64-bit non-prefetchable BAR. >>>> Such BARs can not be allocated in a prefetchable host bridge window >>>> (unlike the converse, i.e., allocating a prefetchable BAR in a >>>> non-prefetchable host bridge window is fine) >>>> >>>> 64-bit non-prefetchable host bridge windows cannot be forwarded by PCI >>>> to PCI bridges, they simply lack the BAR registers to describe them. >>>> Therefore, non-prefetchable endpoint BARs (even 64-bit ones) need to >>>> be carved out of a host bridge's non-prefetchable 32-bit window if >>>> they need to pass through a bridge. >>> >>> Thank you for the explanation. I also looked at the PCI-to-PCI Bridge >>> spec to understand where some of the limitations are coming from. >>> >>>> So the error seems to be here that the host bridge's 32-bit >>>> non-prefetchable window has the 64-bit attribute set, even though it >>>> resides below 4 GB entirely. I suppose that the resource allocation >>>> could be made more forgiving (and it was in the past, before commit >>>> 9d57e61bf723 was applied). However, I would strongly recommend not >>>> deviating from common practice, and just describe the 32-bit >>>> addressable non-prefetchable resource window as such. >>> >>> IIUC, the host bridge's configuration (64-bit on non-prefetchable >>> window) is based on what the hardware advertises. >>> >> >> What do you mean by 'what the hardware advertises'? The host bridge is >> apparently configured to decode a 32-bit addressable window as MMIO, >> and the question is why this window has the 64-bit attribute set in >> the DT description. >> >>> Can you elaborate on what you have in mind to correct the >>> non-prefetchable resource window? Are you thinking of adding a quirk >>> somewhere to address this? >>> >> >> No. Just fix the DT. > > Yes DTS changes are needed as well as some more core driver changes. > > As per the Rk3399 TRM (Rockchip RK3399 TRM V1.3 Part2.pdf) > [0] https://rockchip.fr/Rockchip%20RK3399%20TRM%20V1.3%20Part2.pdf > > I had made the following dts changes relates to ranges as per PCI below. > > *17.6.1 Internal Register Address Mapping > Table 17-23 Global Address Map for Core Local Management* > > diff --git a/arch/arm64/boot/dts/rockchip/rk3399.dtsi > b/arch/arm64/boot/dts/rockchip/rk3399.dtsi > index 634a91af8e83..796b44e07be1 100644 > --- a/arch/arm64/boot/dts/rockchip/rk3399.dtsi > +++ b/arch/arm64/boot/dts/rockchip/rk3399.dtsi > @@ -199,7 +199,7 @@ xin24m: xin24m { > > pcie0: pcie@f8000000 { > compatible = "rockchip,rk3399-pcie"; > - reg = <0x0 0xf8000000 0x0 0x2000000>, > + reg = <0x0 0xf8000000 0x0 0x6000000>, > <0x0 0xfd000000 0x0 0x1000000>; > reg-names = "axi-base", "apb-base"; > device_type = "pci"; > @@ -227,8 +227,8 @@ pcie0: pcie@f8000000 { > <&pcie_phy 2>, <&pcie_phy 3>; > phy-names = "pcie-phy-0", "pcie-phy-1", > "pcie-phy-2", "pcie-phy-3"; > - ranges = <0x83000000 0x0 0xfa000000 0x0 0xfa000000 0x0 > 0x1e00000>, > - <0x81000000 0x0 0xfbe00000 0x0 0xfbe00000 0x0 > 0x100000>; > + ranges = <0x83000000 0x0 0xfd800000 0x0 0xfd810000 0x0 > 0x100000>, > + <0x81000000 0x0 0xfd800000 0x0 0xfda00000 0x0 > 0x100000>; > resets = <&cru SRST_PCIE_CORE>, <&cru SRST_PCIE_MGMT>, > <&cru SRST_PCIE_MGMT_STICKY>, <&cru SRST_PCIE_PIPE>, > <&cru SRST_PCIE_PM>, <&cru SRST_P_PCIE>, > @@ -2040,6 +2040,21 @@ pcfg_pull_up_2ma: pcfg-pull-up-2ma { > drive-strength = <2>; > > Also, the BAR configuration is missing some tuning bits missing, > * 17.6.7.1.45 Root Complex BAR Configuration Register.* > > Earlier I had to face this issue on my Rk3399 board (Odroid n1), but I > could not resolve the issue. > > [1] https://patchwork.kernel.org/project/linux-rockchip/patch/1590023130-137406-1-git-send-email-shawn.lin@rock-chips.com/ > > How can I debug the PCIe handshake messages to explore further? > > [alarm@alarm ~]$ dmesg | grep pci > [ 1.399919] ehci-pci: EHCI PCI platform driver > [ 1.538434] ohci-pci: OHCI PCI platform driver > [ 7.112556] rockchip-pcie f8000000.pcie: host bridge /pcie@f8000000 ranges: > [ 7.120583] rockchip-pcie f8000000.pcie: Parsing ranges property... > [ 7.134628] rockchip-pcie f8000000.pcie: MEM > 0x00fd810000..0x00fd90ffff -> 0x00fd800000 > [ 7.144148] rockchip-pcie f8000000.pcie: IO > 0x00fda00000..0x00fdafffff -> 0x00fd800000 > [ 7.165435] rockchip-pcie f8000000.pcie: can't request region for > resource [mem 0xf8000000-0xfdffffff] > [ 7.182904] rockchip-pcie: probe of f8000000.pcie failed with error -16
Sorry, you've changed your DT for unknown reasons to put the memory and I/O windows at the same bus address, and now you want help debugging why trying to put two things at the same address gives -EBUSY?
:/
Is it Friday already?
Robin.
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