On Mon, Jun 13, 2022 at 6:36 PM Baolu Lu <baolu...@linux.intel.com> wrote: > > On 2022/6/14 04:57, Jerry Snitselaar wrote: > > On Thu, May 12, 2022 at 10:13:09AM -0500, Steve Wahl wrote: > >> To support up to 64 sockets with 10 DMAR units each (640), make the > >> value of DMAR_UNITS_SUPPORTED adjustable by a config variable, > >> CONFIG_DMAR_UNITS_SUPPORTED, and make it's default 1024 when MAXSMP is > >> set. > >> > >> If the available hardware exceeds DMAR_UNITS_SUPPORTED (previously set > >> to MAX_IO_APICS, or 128), it causes these messages: "DMAR: Failed to > >> allocate seq_id", "DMAR: Parse DMAR table failure.", and "x2apic: IRQ > >> remapping doesn't support X2APIC mode x2apic disabled"; and the system > >> fails to boot properly. > >> > >> Signed-off-by: Steve Wahl <steve.w...@hpe.com> > >> --- > >> > >> Note that we could not find a reason for connecting > >> DMAR_UNITS_SUPPORTED to MAX_IO_APICS as was done previously. Perhaps > >> it seemed like the two would continue to match on earlier processors. > >> There doesn't appear to be kernel code that assumes that the value of > >> one is related to the other. > >> > >> v2: Make this value a config option, rather than a fixed constant. The > >> default > >> values should match previous configuration except in the MAXSMP case. > >> Keeping the > >> value at a power of two was requested by Kevin Tian. > >> > >> drivers/iommu/intel/Kconfig | 6 ++++++ > >> include/linux/dmar.h | 6 +----- > >> 2 files changed, 7 insertions(+), 5 deletions(-) > >> > >> diff --git a/drivers/iommu/intel/Kconfig b/drivers/iommu/intel/Kconfig > >> index 247d0f2d5fdf..fdbda77ac21e 100644 > >> --- a/drivers/iommu/intel/Kconfig > >> +++ b/drivers/iommu/intel/Kconfig > >> @@ -9,6 +9,12 @@ config DMAR_PERF > >> config DMAR_DEBUG > >> bool > >> > >> +config DMAR_UNITS_SUPPORTED > >> + int "Number of DMA Remapping Units supported" > > > > Also, should there be a "depends on (X86 || IA64)" here? > > Do you have any compilation errors or warnings? > > Best regards, > baolu >
I think it is probably harmless since it doesn't get used elsewhere, but our tooling was complaining to me because DMAR_UNITS_SUPPORTED was being autogenerated into the configs for the non-x86 architectures we build (aarch64, s390x, ppcle64). We have files corresponding to the config options that it looks at, and I had one for x86 and not the others so it noticed the discrepancy. > > > >> + default 1024 if MAXSMP > >> + default 128 if X86_64 > >> + default 64 > >> + > >> config INTEL_IOMMU > >> bool "Support for Intel IOMMU using DMA Remapping Devices" > >> depends on PCI_MSI && ACPI && (X86 || IA64) > >> diff --git a/include/linux/dmar.h b/include/linux/dmar.h > >> index 45e903d84733..0c03c1845c23 100644 > >> --- a/include/linux/dmar.h > >> +++ b/include/linux/dmar.h > >> @@ -18,11 +18,7 @@ > >> > >> struct acpi_dmar_header; > >> > >> -#ifdef CONFIG_X86 > >> -# define DMAR_UNITS_SUPPORTED MAX_IO_APICS > >> -#else > >> -# define DMAR_UNITS_SUPPORTED 64 > >> -#endif > >> +#define DMAR_UNITS_SUPPORTED CONFIG_DMAR_UNITS_SUPPORTED > >> > >> /* DMAR Flags */ > >> #define DMAR_INTR_REMAP 0x1 > >> -- > >> 2.26.2 > >> > > > _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu
