On Wed, Dec 27, 2023 at 12:00 PM Lorenzo Pieralisi <lpieralisi@xxxxxxxxxx> wrote: > > This series is v4 of previous series: > > v3: https://lore.kernel.org/all/20231006125929.48591-1-lpieralisi@xxxxxxxxxx > v2: https://lore.kernel.org/all/20230906094139.16032-1-lpieralisi@xxxxxxxxxx > v1: https://lore.kernel.org/all/20230905104721.52199-1-lpieralisi@xxxxxxxxxx > > v3 -> v4: > - Dropped patches [1-3], already merged > - Added Linuxized ACPICA changes accepted upstream > - Rebased against v6.7-rc3 > > v2 -> v3: > - Added ACPICA temporary changes and ACPI changes to implement > ECR https://bugzilla.tianocore.org/show_bug.cgi?id=4557 > - ACPI changes are for testing purposes - subject to ECR code > first approval > > v1 -> v2: > - Updated DT bindings as per feedback > - Updated patch[2] to use GIC quirks infrastructure > > Original cover letter > --- > The GICv3 architecture specifications provide a means for the > system programmer to set the shareability and cacheability > attributes the GIC components (redistributors and ITSes) use > to drive memory transactions. > > Albeit the architecture give control over shareability/cacheability > memory transactions attributes (and barriers), it is allowed to > connect the GIC interconnect ports to non-coherent memory ports > on the interconnect, basically tying off shareability/cacheability > "wires" and de-facto making the redistributors and ITSes non-coherent > memory observers. > > This series aims at starting a discussion over a possible solution > to this problem, by adding to the GIC device tree bindings the > standard dma-noncoherent property. The GIC driver uses the property > to force the redistributors and ITSes shareability attributes to > non-shareable, which consequently forces the driver to use CMOs > on GIC memory tables. > > On ARM DT DMA is default non-coherent, so the GIC driver can't rely > on the generic DT dma-coherent/non-coherent property management layer > (of_dma_is_coherent()) which would default all GIC designs in the field > as non-coherent; it has to rely on ad-hoc dma-noncoherent property handling. > > When a consistent approach is agreed upon for DT an equivalent binding will > be put forward for ACPI based systems. > > Lorenzo Pieralisi (3): > ACPICA: MADT: Add GICC online capable bit handling > ACPICA: MADT: Add new MADT GICC/GICR/ITS non-coherent flags handling > irqchip/gic-v3: Enable non-coherent redistributors/ITSes ACPI probing > > drivers/acpi/processor_core.c | 21 +++++++++++++++++++++ > drivers/irqchip/irq-gic-common.h | 8 ++++++++ > drivers/irqchip/irq-gic-v3-its.c | 4 ++++ > drivers/irqchip/irq-gic-v3.c | 9 +++++++++ > include/acpi/actbl2.h | 12 ++++++++++-- > include/linux/acpi.h | 3 +++ > 6 files changed, 55 insertions(+), 2 deletions(-) > > -- I can apply the first 2 patches, but I would need an ACK for the 3rd one. Alternatively, feel free to add Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx> to the first 2 patches and route them via ARM64. Thanks!
