| Message ID | 20240123110332.112797-1-lpieralisi@kernel.org (mailing list archive) |
|---|---|
| Headers | show |
| Series | irqchip/gic-v3: Enable non-coherent GIC designs probing | expand |
On Tue, Jan 23, 2024 at 12:03:31PM +0100, Lorenzo Pieralisi wrote: > This series is v5 of previous series: > > v4: https://lore.kernel.org/all/20231227110038.55453-1-lpieralisi@kernel.org > v3: https://lore.kernel.org/all/20231006125929.48591-1-lpieralisi@kernel.org > v2: https://lore.kernel.org/all/20230906094139.16032-1-lpieralisi@kernel.org > v1: https://lore.kernel.org/all/20230905104721.52199-1-lpieralisi@kernel.org > > v4 -> v5 > - ACPICA patches merged for v6.8 > - Refactored ACPI parsing code according to review > - Rebased against v6.8-rc1 Hi Marc, all, this is not an urgent fix (I don't think there is any ACPI platform affected in the field so it is not even a fix), I am just asking please what should I do with it, I appreciate it is late in the cycle (and I know some fixes got merged in -rcX leading up to -rc7 that are pre-requisite for this patch to work). Thanks, Lorenzo > 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 (1): > irqchip/gic-v3: Enable non-coherent redistributors/ITSes ACPI probing > > drivers/acpi/processor_core.c | 15 +++++++++++++++ > drivers/irqchip/irq-gic-v3-its.c | 4 ++++ > drivers/irqchip/irq-gic-v3.c | 9 +++++++++ > include/linux/acpi.h | 3 +++ > 4 files changed, 31 insertions(+) > > -- > 2.34.1 >
On Wed, Mar 06, 2024 at 03:43:32PM +0100, Lorenzo Pieralisi wrote: > On Tue, Jan 23, 2024 at 12:03:31PM +0100, Lorenzo Pieralisi wrote: > > This series is v5 of previous series: > > > > v4: https://lore.kernel.org/all/20231227110038.55453-1-lpieralisi@kernel.org > > v3: https://lore.kernel.org/all/20231006125929.48591-1-lpieralisi@kernel.org > > v2: https://lore.kernel.org/all/20230906094139.16032-1-lpieralisi@kernel.org > > v1: https://lore.kernel.org/all/20230905104721.52199-1-lpieralisi@kernel.org > > > > v4 -> v5 > > - ACPICA patches merged for v6.8 > > - Refactored ACPI parsing code according to review > > - Rebased against v6.8-rc1 > > Hi Marc, all, > > this is not an urgent fix (I don't think there is any ACPI platform > affected in the field so it is not even a fix), I am just asking please > what should I do with it, I appreciate it is late in the cycle (and I > know some fixes got merged in -rcX leading up to -rc7 that are > pre-requisite for this patch to work). Hi, just a reminder to ask how to proceed with this patch, I know it is not urgent, just to understand how to handle it please. The related ACPICA changes are already merged in the mainline. Thanks, Lorenzo > Thanks, > Lorenzo > > > 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 (1): > > irqchip/gic-v3: Enable non-coherent redistributors/ITSes ACPI probing > > > > drivers/acpi/processor_core.c | 15 +++++++++++++++ > > drivers/irqchip/irq-gic-v3-its.c | 4 ++++ > > drivers/irqchip/irq-gic-v3.c | 9 +++++++++ > > include/linux/acpi.h | 3 +++ > > 4 files changed, 31 insertions(+) > > > > -- > > 2.34.1 > >