riscv: Enable pcpu page first chunk allocator

As explained in commit 6ea529a2037c ("percpu: make embedding first chunk
allocator check vmalloc space size"), the embedding first chunk allocator
needs the vmalloc space to be larger than the maximum distance between
units which are grouped into NUMA nodes.

On a very sparse NUMA configurations and a small vmalloc area (for example,
it is 64GB in sv39), the allocation of dynamic percpu data in the vmalloc
area could fail.

So provide the pcpu page allocator as a fallback in case we fall into
such a sparse configuration (which happened in arm64 as shown by
commit 09cea6195073 ("arm64: support page mapping percpu first chunk
allocator")).

Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>

diff --git a/arch/riscv/Kconfig b/arch/riscv/Kconfig
index 95a2a06acc6a62412894e491c3bfd5d4a161d15b..80e9b2ac34ab24eceb2f7f66485a6ac83f1096b0 100644 (file)
--- a/arch/riscv/Kconfig
+++ b/arch/riscv/Kconfig
@@ -414,7 +414,9 @@ config NUMA
        depends on SMP && MMU
        select ARCH_SUPPORTS_NUMA_BALANCING
        select GENERIC_ARCH_NUMA
+       select HAVE_SETUP_PER_CPU_AREA
        select NEED_PER_CPU_EMBED_FIRST_CHUNK
+       select NEED_PER_CPU_PAGE_FIRST_CHUNK
        select OF_NUMA
        select USE_PERCPU_NUMA_NODE_ID
        help

diff --git a/arch/riscv/mm/kasan_init.c b/arch/riscv/mm/kasan_init.c
index 5e39dcf23fdbc15e12cedcf6b75a51ccfea6cf9d..4c9a2c527f08ff26a5a98d46136fc2596c84add3 100644 (file)
--- a/arch/riscv/mm/kasan_init.c
+++ b/arch/riscv/mm/kasan_init.c
@@ -438,6 +438,14 @@ static void __init kasan_shallow_populate(void *start, void *end)
        kasan_shallow_populate_pgd(vaddr, vend);
 }
 
+#ifdef CONFIG_KASAN_VMALLOC
+void __init kasan_populate_early_vm_area_shadow(void *start, unsigned long size)
+{
+       kasan_populate(kasan_mem_to_shadow(start),
+                      kasan_mem_to_shadow(start + size));
+}
+#endif
+
 static void __init create_tmp_mapping(void)
 {
        void *ptr;