On Tue, 14 Mar 2023 13:25:28 +0000, Lucas Tanure <lucas.tanure@xxxxxxxxxxxxx> wrote: > > On 10-03-2023 12:04, Robin Murphy wrote: > > On 2023-03-10 11:41, Peter Geis wrote: > >> On Fri, Mar 10, 2023 at 3:05 AM Lucas Tanure > >> <lucas.tanure@xxxxxxxxxxxxx> wrote: > >>> > >>> The GIC600 integration in RK356x, used in rk3588, doesn't support > >>> any of the shareability or cacheability attributes, and requires > >>> both values to be set to 0b00 for all the ITS and Redistributor > >>> tables. > >>> > >>> This is loosely based on prior work from XiaoDong Huang and > >>> Peter Geis fixing this issue specifically for Rockchip 356x. > >> > >> Good Morning, > >> > >> Since the gic is using dma, would it be reasonable to have all memory > >> allocations be requested with the GFP_DMA flag? Otherwise this doesn't > >> fully solve the problem for rk356x, where only the lower 4GB range is > >> DMA capable, but this tends to get allocated in the upper 4GB on 8GB > >> boards. > > > > Not really, because there's no fixed definition of what GFP_DMA > > actually means, and it may mean nothing (same for GFP_DMA32, which > > may or may not be meaningful depending on kernel config and platform > > topology). Drivers should really use the DMA API allocation > > functions if they care about what they get, which comes back round > > to the notion from years ago of converting the ITS driver to a > > regular platform driver, so it can benefit from regular DT concepts > > like "dma-ranges" automatically. > > > > Thanks, > > Robin. > > > I am looking how to do that conversion to platform driver. > But about the communication between irq-gic-v3-its and irq-gic-v3. > Should irq-gic-v3-its be a MFD child of irq-gic-v3? MFD? I'd rather suggest an VME bus driver. ;-) Seriously, this is an interrupt controller. Nothing else. It should probe the parent irqdomain, and stack onto that. No parent? Probe deferral. > Or use the component bind/unbind framework? I don't understand what you mean here. M. -- Without deviation from the norm, progress is not possible.
