On Wed, 9 Jul 2025 at 07:05, Biju Das <biju.das.jz@xxxxxxxxxxxxxx> wrote: > > From: Claudiu Beznea <claudiu.beznea@xxxxxxxxx> > > On 07.07.2025 11:18, Biju Das wrote: > > >> From: Claudiu <claudiu.beznea@xxxxxxxxx> > > >> Sent: 04 July 2025 17:14 > > >> Subject: [PATCH v3 7/9] arm64: dts: renesas: rzg3s-smarc-som: Update > > >> dma-ranges for PCIe > > >> > > >> From: Claudiu Beznea <claudiu.beznea.uj@xxxxxxxxxxxxxx> > > >> > > >> The first 128MB of memory is reserved on this board for secure area. > > >> Update the PCIe dma-ranges property to reflect this. > > > > > > I see R-Car PCIe dma-ranges[1] and [2] maps all possible DDR area supported by the SoC? > > > Do we need to make board specific as well there? > > > > I'm not familiar with R-Car, but if there are ranges reserved for other purposes, I think we should > > reflect it in board specific device trees. > > Already Linux has this DDR info[1]. Linux provides DMA memory only from this region. > > In your testing, have you faced any issue like system allocated DMA region other than [1] > and you don't want to use it, then the changes are ok?? Exactly. PCI memory must be located in the intersection of dma-ranges in r9a08g045s33.dtsi and the various memory nodes in rzg3s-smarc-som.dtsi. The latter already excludes the secure area. > Not sure, PCIe can work on internal memory such as SRAM? If that is the case, it should be reflected in r9a08g045s33.dtsi. > [1] > https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/tree/arch/arm64/boot/dts/renesas/rzg3s-smarc-som.dtsi?h=next-20250708#n31 Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds
