Hi Marc, On Wed, Apr 8, 2015 at 12:44 AM, Marc Zyngier <marc.zyngier@xxxxxxx> wrote: > On Tue, 7 Apr 2015 20:56:48 +0100 > Duc Dang <dhdang@xxxxxxx> wrote: > > Hi Duc, > >> On Wed, Mar 18, 2015 at 11:52 AM, Marc Zyngier <marc.zyngier@xxxxxxx> wrote: >> > On 18/03/15 18:29, Duc Dang wrote: >> >> On Wed, Mar 18, 2015 at 11:05 AM, Marc Zyngier <marc.zyngier@xxxxxxx> wrote: >> >>> On 04/03/15 19:39, Duc Dang wrote: >> >>>> X-Gene v1 SOC supports total 2688 MSI/MSIX vectors coalesced into >> >>>> 16 HW IRQ lines. >> >>>> >> >>>> Signed-off-by: Duc Dang <dhdang@xxxxxxx> >> >>>> Signed-off-by: Tanmay Inamdar <tinamdar@xxxxxxx> >> >>> >> >>> I just had a quick look at this, and this seems to be going in the exact >> >>> opposite direction compared to what we now have on arm64, where we move >> >>> away from using struct msi_controller for most thing, and implement PCI >> >>> MSI/MSIX in a generic way, using MSI domains. >> >>> >> >>> I suggest you have a look at how GICv2m and GICv3 ITS implement the MSI >> >>> support. You can also have a look at what I did for the Tegra MSI >> >>> controller in this patch: >> >>> >> >>> https://git.kernel.org/cgit/linux/kernel/git/maz/arm-platforms.git/commit/?h=irq/kill-msi-controller&id=83b3602fcee7972b9d549ed729b56ec28de16081 >> >>> >> >>> Eventually, the plan is to kill msi_controller entirely, so introducing >> >>> new drivers that rely on it is not something I'm eager to see. >> >> >> >> Thanks, Marc. >> >> >> >> X-Gene 1 MSI is handled by separate MSI controller block, so its >> >> driver implementation is different from GICv2m and GICv3. I will refer >> > >> > It will certainly be different in the sense that you won't use a stacked >> > domain on top of the GIC. But what I want to see is the use of a generic >> > pci_msi_domain on top of an irq_domain, just like we have on v2m and v3. >> > Thomas has also been vocal enough about that in the past, and x86 is >> > going down that road as well. >> > >> >> to what you did for Tegra MSI, but I don't see your latest changes in >> >> 4.0-rc4. Is the change you made for Tegra MSI going to mainline soon? >> > >> > Not yet. As you can see in this branch, this relies on some other >> > cleanups. But you can already convert most of your driver and put it in >> > the shape that matches what we have for v2m and v3. Once the required >> > cleanups are in, I'll remove the last traces of msi_controller myself if >> > necessary. >> > >> >> Hi Marc, Bjorn, >> >> I follow Marc's suggestion and convert my X-Gene 1 MSI driver to >> remove msi_controller struct and use generic pci_msi_domain on top of >> an irq_domain. The code requires Marc's changes in >> irq/kill-msi-controller branch to be compiled and function correctly, >> so I plan to post the patch on top of Marc's tree. Please let me know >> if you think I should have different approach to post this patch. > > I don't think you should rely on this branch just yet (this is why I > suggested matching what we currently have for GICv2m and v3). Keeping > msi_controller is fine at the moment, even if we only use to store the > MSI domain. If and when this series makes it to mainline, I'll go over > the individual drivers to convert them to the new scheme, just like I > did for GIC and Tegra. > >> Another question I have is when do you plan to roll out this hierarchy >> irq domain implementation for MSI, as I see some of Marc's changes to >> kill msi_controller structure and implement MSI irq domain still does >> not get into Bjorn's tree. > > I'm still tinkering with it (I have some long standing comments from > Bjorn to address), and I'm working on non-PCI MSI support at the moment. > > But the core MSI irq domain stuff is already in (this is what GICv2m > and GICv3 ITS are using), and this should be an easy thing to convert > your code. > > Please let me know if I can be of any help. > Thanks for your suggestion. I converted my code using the core MSI irq domain (similar to GICv2m, still have msi_controller structure) and posted a new version (v3) of this patch. Can you please take a look when you have some time? Regards, Duc Dang. > Thanks, > > M. > -- > Without deviation from the norm, progress is not possible. -- To unsubscribe from this list: send the line "unsubscribe linux-pci" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
