It is not necessary any RISCV platform has ZONE_DMA32. Platforms that not support ZONE_DMA32 should set CONFIG_NONPORTABLE because lack of ZONE_DMA32 makes such platform non-portable indeed Example - if platform has no DRAM in [0..4G] region, it will report failure like below each boot. [ 0.088709] swapper/0: page allocation failure: order:7, mode:0xcc4(GFP_KERNEL|GFP_DMA32), nodemask=(null),cpuset=/ [ 0.088832] CPU: 0 UID: 0 PID: 1 Comm: swapper/0 Not tainted 6.11.0-rc5 #30 [ 0.088864] Call Trace: [ 0.088869] [<ffffffff800059f2>] dump_backtrace+0x1c/0x24 [ 0.088910] [<ffffffff805f328c>] show_stack+0x2c/0x38 [ 0.088957] [<ffffffff805fd800>] dump_stack_lvl+0x52/0x74 [ 0.088987] [<ffffffff805fd836>] dump_stack+0x14/0x1c [ 0.089010] [<ffffffff801a23a8>] warn_alloc+0xf4/0x176 [ 0.089041] [<ffffffff801a3052>] __alloc_pages_noprof+0xc28/0xcb4 [ 0.089067] [<ffffffff80086eda>] atomic_pool_expand+0x62/0x1f8 [ 0.089090] [<ffffffff8080d674>] __dma_atomic_pool_init+0x46/0x9e [ 0.089115] [<ffffffff8080d762>] dma_atomic_pool_init+0x96/0x11c [ 0.089139] [<ffffffff80002146>] do_one_initcall+0x5c/0x1b2 [ 0.089158] [<ffffffff8080127c>] kernel_init_freeable+0x214/0x274 [ 0.089190] [<ffffffff805fefd8>] kernel_init+0x1e/0x10a [ 0.089209] [<ffffffff8060748a>] ret_from_fork+0xe/0x1c Signed-off-by: Vladimir Kondratiev <vladimir.kondratiev@xxxxxxxxxxxx> --- arch/riscv/Kconfig | 3 ++- mm/Kconfig | 2 +- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig index 0f37596a7707..417c6051b679 100644 --- a/arch/riscv/Kconfig +++ b/arch/riscv/Kconfig @@ -51,6 +51,7 @@ config RISCV select ARCH_HAS_TICK_BROADCAST if GENERIC_CLOCKEVENTS_BROADCAST select ARCH_HAS_UBSAN select ARCH_HAS_VDSO_DATA + select ARCH_HAS_ZONE_DMA_SET if 64BIT && NONPORTABLE select ARCH_KEEP_MEMBLOCK if ACPI select ARCH_MHP_MEMMAP_ON_MEMORY_ENABLE if 64BIT && MMU select ARCH_OPTIONAL_KERNEL_RWX if ARCH_HAS_STRICT_KERNEL_RWX @@ -208,7 +209,7 @@ config RISCV select TRACE_IRQFLAGS_SUPPORT select UACCESS_MEMCPY if !MMU select USER_STACKTRACE_SUPPORT - select ZONE_DMA32 if 64BIT + select ZONE_DMA32 if 64BIT && !NONPORTABLE config RUSTC_SUPPORTS_RISCV def_bool y diff --git a/mm/Kconfig b/mm/Kconfig index 4c9f5ea13271..f96f812193a4 100644 --- a/mm/Kconfig +++ b/mm/Kconfig @@ -1057,7 +1057,7 @@ config ZONE_DMA config ZONE_DMA32 bool "Support DMA32 zone" if ARCH_HAS_ZONE_DMA_SET depends on !X86_32 - default y if ARM64 + default y if ARM64 || (RISCV && 64BIT) config ZONE_DEVICE bool "Device memory (pmem, HMM, etc...) hotplug support" -- 2.43.0
