Messages in this thread | | | Subject | Re: [PATCH 2/4] powerpc/pseries/iommu: Implement ibm,reset-pe-dma-windows rtas call | From | Alexey Kardashevskiy <> | Date | Tue, 23 Jun 2020 11:11:59 +1000 |
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On 23/06/2020 04:58, Leonardo Bras wrote: > Hello Alexey, thanks for the feedback! > > On Mon, 2020-06-22 at 20:02 +1000, Alexey Kardashevskiy wrote: >> >> On 19/06/2020 15:06, Leonardo Bras wrote: >>> Platforms supporting the DDW option starting with LoPAR level 2.7 implement >>> ibm,ddw-extensions. The first extension available (index 2) carries the >>> token for ibm,reset-pe-dma-windows rtas call, which is used to restore >>> the default DMA window for a device, if it has been deleted. >>> >>> It does so by resetting the TCE table allocation for the PE to it's >>> boot time value, available in "ibm,dma-window" device tree node. >>> >>> Signed-off-by: Leonardo Bras <leobras.c@gmail.com> >>> --- >>> arch/powerpc/platforms/pseries/iommu.c | 33 ++++++++++++++++++++++++++ >>> 1 file changed, 33 insertions(+) >>> >>> diff --git a/arch/powerpc/platforms/pseries/iommu.c b/arch/powerpc/platforms/pseries/iommu.c >>> index e5a617738c8b..5e1fbc176a37 100644 >>> --- a/arch/powerpc/platforms/pseries/iommu.c >>> +++ b/arch/powerpc/platforms/pseries/iommu.c >>> @@ -1012,6 +1012,39 @@ static phys_addr_t ddw_memory_hotplug_max(void) >>> return max_addr; >>> } >>> >>> +/* >>> + * Platforms supporting the DDW option starting with LoPAR level 2.7 implement >>> + * ibm,ddw-extensions, which carries the rtas token for >>> + * ibm,reset-pe-dma-windows. >>> + * That rtas-call can be used to restore the default DMA window for the device. >>> + */ >>> +static void reset_dma_window(struct pci_dev *dev, struct device_node *par_dn) >>> +{ >>> + int ret; >>> + u32 cfg_addr, ddw_ext[3]; >>> + u64 buid; >>> + struct device_node *dn; >>> + struct pci_dn *pdn; >>> + >>> + ret = of_property_read_u32_array(par_dn, "ibm,ddw-extensions", >>> + &ddw_ext[0], 3); >> >> s/3/2/ as for the reset extension you do not need the "64bit largest >> block" extension. > > Sure, I will update this. > >> >> >>> + if (ret) >>> + return; >>> + >>> + dn = pci_device_to_OF_node(dev); >>> + pdn = PCI_DN(dn); >>> + buid = pdn->phb->buid; >>> + cfg_addr = ((pdn->busno << 16) | (pdn->devfn << 8)); >>> + >>> + ret = rtas_call(ddw_ext[1], 3, 1, NULL, cfg_addr, >> >> Here the "reset" extention is in ddw_ext[1]. Hm. 1/4 has a bug then. > > Humm, in 1/4 I used dd_ext[0] (how many extensions) and ddw_ext[2] (64- > bit largest window count). I fail to see the bug here.
There is none, my bad :)
>> And I am pretty sure it won't compile as reset_dma_window() is not used >> and it is static so fold it into one the next patches. Thanks, > > Sure, I will do that. > I was questioning myself about this and thought it would be better to > split for easier revision.
People separate things when a patch is really huge but even then I miss the point - I'd really like to see a new function _and_ its uses in the same patch, otherwise I either need to jump between mails or apply the series, either is little but extra work :) Thanks,
>> >> >>> + BUID_HI(buid), BUID_LO(buid)); >>> + if (ret) >>> + dev_info(&dev->dev, >>> + "ibm,reset-pe-dma-windows(%x) %x %x %x returned %d ", >>> + ddw_ext[1], cfg_addr, BUID_HI(buid), BUID_LO(buid), >>> + ret); >>> +} >>> + >>> /* >>> * If the PE supports dynamic dma windows, and there is space for a table >>> * that can map all pages in a linear offset, then setup such a table, >>> > > Best regards, > Leonardo >
-- Alexey
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