Re: [PATCH 10/10] ACPI: IORT: Allow COMPILE_TEST of IORT
On Wed, Nov 29, 2023 at 03:12:40PM -0400, Jason Gunthorpe wrote: > On Wed, Nov 29, 2023 at 01:55:04PM +0100, Lorenzo Pieralisi wrote: > > > I don't think it should be done this way. Is the goal compile testing > > IORT code ? > > Yes > > > If so, why are we forcing it through the SMMU (only because > > it can be compile tested while eg SMMUv3 driver can't ?) menu entry ? > > Because something needs to select it, and SMMU is one of the places > that are implicitly using it. > > It isn't (and shouldn't be) a user selectable kconfig. Currently the > only thing that selects it is the ARM64 master kconfig. I never said it should be a user selectable kconfig. I said that I don't like using the SMMU entry (only) to select it just because that entry allows COMPILE_TEST. > > This looks a bit artificial (and it is unclear from the Kconfig > > file why only that driver selects IORT, it looks like eg the SMMUv3 > > does not have the same dependency - there is also the SMMUv3 perf > > driver to consider). > > SMMUv3 doesn't COMPILE_TEST so it picks up the dependency transitivity > through ARM64. I'm not sure why IORT was put as a global ARM64 kconfig > dependency and not put in the places that directly need it. Because IORT is used by few ARM64 system IPs (that are enabled by default, eg GIC), it makes sense to have a generic ARM64 select (if ACPI). > "perf driver" ? There is a bunch of GIC stuff that uses this too but I > don't know if it compile tests. "SMMUv3 perf driver" drivers/perf/arm_smmuv3_pmu.c > > Maybe we can move IORT code into drivers/acpi and add a silent config > > option there with a dependency on ARM64 || COMPILE_TEST. > > That seems pretty weird to me, this is the right way to approach it, > IMHO. Making an entire directory condition is pretty incompatible with > COMPILE_TEST as a philosophy. That's not what I was suggesting. I was suggesting to move iort.c (or some portions of it) into drivers/acpi if we care enough to compile test it on arches !ARM64. It is also weird to have a file in drivers/acpi/arm64 that you want to compile test on other arches IMO (and I don't think it is very useful to compile test it either). > > Don't know but at least it is clearer. As for the benefits of compile > > testing IORT code - yes the previous patch is a warning to fix but > > I am not so sure about the actual benefits. > > IMHO COMPILE_TEST is an inherently good thing. It makes development > easier for everyone because you have a less fractured code base to > work with. I am talking about IORT code, not COMPILE_TEST as a whole. I am not sure what "less fractured" means in this context. Anyway - it is not a big deal either way but I don't like selecting ACPI_IORT only on kconfig entries that allow COMPILE_TEST to implicitly compile test it so *if* we want to do it we will have to do it differently. Thanks, Lorenzo ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
Re: [PATCH 10/10] ACPI: IORT: Allow COMPILE_TEST of IORT
On Thu, Nov 30, 2023 at 12:12:26PM +0100, Lorenzo Pieralisi wrote: > On Wed, Nov 29, 2023 at 03:12:40PM -0400, Jason Gunthorpe wrote: > > On Wed, Nov 29, 2023 at 01:55:04PM +0100, Lorenzo Pieralisi wrote: > > > > > I don't think it should be done this way. Is the goal compile testing > > > IORT code ? > > > > Yes > > > > > If so, why are we forcing it through the SMMU (only because > > > it can be compile tested while eg SMMUv3 driver can't ?) menu entry ? > > > > Because something needs to select it, and SMMU is one of the places > > that are implicitly using it. > > > > It isn't (and shouldn't be) a user selectable kconfig. Currently the > > only thing that selects it is the ARM64 master kconfig. > > I never said it should be a user selectable kconfig. I said that > I don't like using the SMMU entry (only) to select it just because > that entry allows COMPILE_TEST. So you would like each of the drivers that use it to select it? > > SMMUv3 doesn't COMPILE_TEST so it picks up the dependency transitivity > > through ARM64. I'm not sure why IORT was put as a global ARM64 kconfig > > dependency and not put in the places that directly need it. > > Because IORT is used by few ARM64 system IPs (that are enabled by > default, eg GIC), it makes sense to have a generic ARM64 select (if ACPI). IMHO that is not a good way to use kconfig, it is obfuscating and doesn't support things like COMPILE_TEST. > > > Maybe we can move IORT code into drivers/acpi and add a silent config > > > option there with a dependency on ARM64 || COMPILE_TEST. > > > > That seems pretty weird to me, this is the right way to approach it, > > IMHO. Making an entire directory condition is pretty incompatible with > > COMPILE_TEST as a philosophy. > > That's not what I was suggesting. I was suggesting to move iort.c (or > some portions of it) into drivers/acpi if we care enough to compile test > it on arches !ARM64. > > It is also weird to have a file in drivers/acpi/arm64 that you want > to compile test on other arches IMO (and I don't think it is very useful > to compile test it either). Why? Just because the directory is named "arm64" doesn't mean it should be excluded from COMPILE_TEST. arch/arm64 yes, but not random directories in the driver tree. Stuff under drivers/ should strive to get 100% COMPILE_TEST coverage as much as practical. This makes everyone else's life easier. Jason ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
Re: [PATCH 10/10] ACPI: IORT: Allow COMPILE_TEST of IORT
On 29/11/2023 12:48 am, Jason Gunthorpe wrote: The arm-smmu driver can COMPILE_TEST on x86, so expand this to also enable the IORT code so it can be COMPILE_TEST'd too. Signed-off-by: Jason Gunthorpe --- drivers/acpi/Kconfig| 2 -- drivers/acpi/Makefile | 2 +- drivers/acpi/arm64/Kconfig | 1 + drivers/acpi/arm64/Makefile | 2 +- drivers/iommu/Kconfig | 1 + 5 files changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/acpi/Kconfig b/drivers/acpi/Kconfig index f819e760ff195a..3b7f77b227d13a 100644 --- a/drivers/acpi/Kconfig +++ b/drivers/acpi/Kconfig @@ -541,9 +541,7 @@ config ACPI_PFRUT To compile the drivers as modules, choose M here: the modules will be called pfr_update and pfr_telemetry. -if ARM64 source "drivers/acpi/arm64/Kconfig" -endif config ACPI_PPTT bool diff --git a/drivers/acpi/Makefile b/drivers/acpi/Makefile index eaa09bf52f1760..4e77ae37b80726 100644 --- a/drivers/acpi/Makefile +++ b/drivers/acpi/Makefile @@ -127,7 +127,7 @@ obj-y += pmic/ video-objs+= acpi_video.o video_detect.o obj-y += dptf/ -obj-$(CONFIG_ARM64) += arm64/ +obj-y += arm64/ obj-$(CONFIG_ACPI_VIOT) += viot.o diff --git a/drivers/acpi/arm64/Kconfig b/drivers/acpi/arm64/Kconfig index b3ed6212244c1e..537d49d8ace69e 100644 --- a/drivers/acpi/arm64/Kconfig +++ b/drivers/acpi/arm64/Kconfig @@ -11,6 +11,7 @@ config ACPI_GTDT config ACPI_AGDI bool "Arm Generic Diagnostic Dump and Reset Device Interface" + depends on ARM64 depends on ARM_SDE_INTERFACE help Arm Generic Diagnostic Dump and Reset Device Interface (AGDI) is diff --git a/drivers/acpi/arm64/Makefile b/drivers/acpi/arm64/Makefile index 143debc1ba4a9d..71d0e635599390 100644 --- a/drivers/acpi/arm64/Makefile +++ b/drivers/acpi/arm64/Makefile @@ -4,4 +4,4 @@ obj-$(CONFIG_ACPI_IORT) += iort.o obj-$(CONFIG_ACPI_GTDT) += gtdt.o obj-$(CONFIG_ACPI_APMT) += apmt.o obj-$(CONFIG_ARM_AMBA)+= amba.o -obj-y += dma.o init.o +obj-$(CONFIG_ARM64)+= dma.o init.o diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig index 7673bb82945b6c..309378e76a9bc9 100644 --- a/drivers/iommu/Kconfig +++ b/drivers/iommu/Kconfig @@ -318,6 +318,7 @@ config ARM_SMMU select IOMMU_API select IOMMU_IO_PGTABLE_LPAE select ARM_DMA_USE_IOMMU if ARM + select ACPI_IORT if ACPI This is incomplete. If you want the driver to be responsible for enabling its own probing mechanisms then you need to select OF and ACPI too. And all the other drivers which probe from IORT should surely also select ACPI_IORT, and thus ACPI as well. And maybe the PCI core should as well because there are general properties of PCI host bridges and devices described in there? But of course that's clearly backwards nonsense, because drivers do not and should not do that, so this change is not appropriate either. The IORT code may not be *functionally* arm64-specific, but logically it very much is - it serves a specification which is tied to the Arm architecture and describes Arm-architecture-specific concepts, within the wider context of ACPI on Arm itself only supporting AArch64, and not AArch32. It's also not like it's driver code that someone might use as an example and copy to a similar driver which could then run on different architectures where a latent theoretical bug becomes real. There's really no practical value to be had from compile-testing IORT. Thanks, Robin. ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
Re: [PATCH 10/10] ACPI: IORT: Allow COMPILE_TEST of IORT
On Thu, Nov 30, 2023 at 02:10:48PM +, Robin Murphy wrote: > > diff --git a/drivers/iommu/Kconfig b/drivers/iommu/Kconfig > > index 7673bb82945b6c..309378e76a9bc9 100644 > > --- a/drivers/iommu/Kconfig > > +++ b/drivers/iommu/Kconfig > > @@ -318,6 +318,7 @@ config ARM_SMMU > > select IOMMU_API > > select IOMMU_IO_PGTABLE_LPAE > > select ARM_DMA_USE_IOMMU if ARM > > + select ACPI_IORT if ACPI > > This is incomplete. If you want the driver to be responsible for enabling > its own probing mechanisms then you need to select OF and ACPI too. Well, yes, we do have that minor issue today that drivers can be compiled without any way to parse any FW and are thus completely useless. Certainly one could make the case this should be depends on OF || ACPI select ACPI_IORT if ACPI And similar in other drivers so they have the minimum dependencies to actually be able to work. This would be the correct way to use kconfig. But who cares? I'm not trying to fix everything here, I'm trying to allow COMPILE_TEST for more sub components of this one driver. > And all the other drivers which probe from IORT should surely also > select ACPI_IORT, and thus ACPI as well. And maybe the PCI core > should as well because there are general properties of PCI host > bridges and devices described in there? Now you are just arguring to an absurdity. > But of course that's clearly backwards nonsense, because drivers do not and > should not do that, so this change is not appropriate either. This patch is about COMPILE_TEST. > theoretical bug becomes real. There's really no practical value to be had > from compile-testing IORT. COMPILE_TEST is to make it easier to maintain the kernel code by reducing the neccessary combinations required to get complete compile coverage. 100% compile test is a laudible goal on its own. I have no idea what you are talking about with "no practical value" just because you don't use COMPILE_TEST doesn't mean it has "no practical value". It exists, people like me use, we can make it better. Why is this even a point of debate? :( Jason ___ linux-snps-arc mailing list linux-snps-arc@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-snps-arc
