* Igor Mammedov <imammedo@xxxxxxxxxx> wrote: > diff --git a/arch/x86/include/asm/acpi.h b/arch/x86/include/asm/acpi.h > index 94c18eb..53d7951 100644 > --- a/arch/x86/include/asm/acpi.h > +++ b/arch/x86/include/asm/acpi.h > @@ -147,6 +147,7 @@ static inline void disable_acpi(void) { } > #ifdef CONFIG_ACPI_NUMA > extern int acpi_numa; > extern int x86_acpi_numa_init(void); > +unsigned long acpi_get_max_possible_pfn(void); > #endif /* CONFIG_ACPI_NUMA */ > > #define acpi_unlazy_tlb(x) leave_mm(x) > @@ -170,4 +171,8 @@ static inline pgprot_t arch_apei_get_mem_attribute(phys_addr_t addr) > } > #endif > > +#ifdef CONFIG_ACPI_HOTPLUG_MEMORY > +extern bool acpi_no_memhotplug; > +#endif /* CONFIG_ACPI_HOTPLUG_MEMORY */ > + > #endif /* _ASM_X86_ACPI_H */ > diff --git a/arch/x86/kernel/pci-swiotlb.c b/arch/x86/kernel/pci-swiotlb.c > index adf0392..61d5ba5 100644 > --- a/arch/x86/kernel/pci-swiotlb.c > +++ b/arch/x86/kernel/pci-swiotlb.c > @@ -88,7 +88,11 @@ int __init pci_swiotlb_detect_4gb(void) > { > /* don't initialize swiotlb if iommu=off (no_iommu=1) */ > #ifdef CONFIG_X86_64 > +#ifdef CONFIG_ACPI_NUMA > + if (!no_iommu && acpi_get_max_possible_pfn() > MAX_DMA32_PFN) > +#else > if (!no_iommu && max_pfn > MAX_DMA32_PFN) > +#endif > swiotlb = 1; > #endif > return swiotlb; > diff --git a/arch/x86/mm/srat.c b/arch/x86/mm/srat.c > index c2aea63..21b33f0 100644 > --- a/arch/x86/mm/srat.c > +++ b/arch/x86/mm/srat.c > @@ -153,10 +153,20 @@ acpi_numa_processor_affinity_init(struct acpi_srat_cpu_affinity *pa) > > #ifdef CONFIG_MEMORY_HOTPLUG > static inline int save_add_info(void) {return 1;} > +static unsigned long max_possible_pfn __initdata; > #else > static inline int save_add_info(void) {return 0;} > #endif > > +unsigned long __init acpi_get_max_possible_pfn(void) > +{ > +#ifdef CONFIG_ACPI_HOTPLUG_MEMORY > + if (!acpi_no_memhotplug) > + return max_possible_pfn; > +#endif > + return max_pfn; > +} > + > /* Callback for parsing of the Proximity Domain <-> Memory Area mappings */ > int __init > acpi_numa_memory_affinity_init(struct acpi_srat_mem_affinity *ma) > @@ -203,6 +213,11 @@ acpi_numa_memory_affinity_init(struct acpi_srat_mem_affinity *ma) > pr_warn("SRAT: Failed to mark hotplug range [mem %#010Lx-%#010Lx] in memblock\n", > (unsigned long long)start, (unsigned long long)end - 1); > > +#ifdef CONFIG_MEMORY_HOTPLUG > + if (max_possible_pfn < PFN_UP(end - 1)) > + max_possible_pfn = PFN_UP(end - 1); > +#endif > + > return 0; > out_err_bad_srat: > bad_srat(); > diff --git a/drivers/acpi/acpi_memhotplug.c b/drivers/acpi/acpi_memhotplug.c > index 6b0d3ef..ae38f57 100644 > --- a/drivers/acpi/acpi_memhotplug.c > +++ b/drivers/acpi/acpi_memhotplug.c > @@ -357,7 +357,7 @@ static void acpi_memory_device_remove(struct acpi_device *device) > acpi_memory_device_free(mem_device); > } > > -static bool __initdata acpi_no_memhotplug; > +bool __initdata acpi_no_memhotplug; > > void __init acpi_memory_hotplug_init(void) > { So I don't disagree with the fix in principle, but the implementation here is rather ugly - it spreads new non-obvious #ifdefs across various critical parts of the kernel. For example this: > #ifdef CONFIG_X86_64 > +#ifdef CONFIG_ACPI_NUMA > + if (!no_iommu && acpi_get_max_possible_pfn() > MAX_DMA32_PFN) > +#else > if (!no_iommu && max_pfn > MAX_DMA32_PFN) > +#endif > swiotlb = 1; > #endif could be cleaned up by introducing a proper max_possible_pfn variable, and setting it from the ACPI code - instead of exporting acpi_get_max_possible_pfn(). Another pattern is: > +#ifdef CONFIG_ACPI_HOTPLUG_MEMORY > + if (!acpi_no_memhotplug) > + return max_possible_pfn; > +#endif this should be driven from the acpi_no_memhotplug knob, instead of spreading acpi_no_memhotplug uses to other callsites. Furthermore, please split these various steps up into multiple steps (and first do the preparatory changes, then fix the bug in the end) - to make it easier to bisect and analyze if we regress existing functionality somewhere. Thanks, Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-acpi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html