Messages in this thread | | | From | Lorenzo Pieralisi <> | Subject | [PATCH v3 0/5] irqchip/gic-v3: Enable non-coherent GIC designs probing | Date | Fri, 6 Oct 2023 14:59:24 +0200 |
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This series is v3 of previous series:
v2: https://lore.kernel.org/all/20230906094139.16032-1-lpieralisi@kernel.org v1: https://lore.kernel.org/all/20230905104721.52199-1-lpieralisi@kernel.org
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 (4): dt-bindings: interrupt-controller: arm,gic-v3: Add dma-noncoherent property irqchip/gic-v3: Enable non-coherent redistributors/ITSes DT probing ACPICA: Add new MADT GICC/GICR/ITS flags handling [code first] irqchip/gic-v3: Enable non-coherent redistributors/ITSes ACPI probing
Marc Zyngier (1): irqchip/gic-v3-its: Split allocation from initialisation of its_node
.../interrupt-controller/arm,gic-v3.yaml | 12 ++ drivers/acpi/processor_core.c | 21 +++ drivers/irqchip/irq-gic-common.h | 12 ++ drivers/irqchip/irq-gic-v3-its.c | 174 +++++++++++------- drivers/irqchip/irq-gic-v3.c | 22 +++ include/acpi/actbl2.h | 11 +- include/linux/acpi.h | 3 + 7 files changed, 189 insertions(+), 66 deletions(-)
-- 2.34.1
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