[PATCH v7 3/7] mm/memory_hotplug: Allow architecture to override memmap on memory support check
From: Aneesh Kumar K.V <hidden>
Date: 2023-08-01 04:45:08
Subsystem:
memory hot(un)plug, memory management, the rest · Maintainers:
David Hildenbrand, Oscar Salvador, Andrew Morton, Linus Torvalds
Some architectures would want different restrictions. Hence add an architecture-specific override. The PMD_SIZE check is moved there. Acked-by: David Hildenbrand <redacted> Signed-off-by: Aneesh Kumar K.V <redacted> --- mm/memory_hotplug.c | 24 ++++++++++++++++++++---- 1 file changed, 20 insertions(+), 4 deletions(-)
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index eca32ccd45cc..746cb7c08c64 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c@@ -1247,10 +1247,26 @@ static int online_memory_block(struct memory_block *mem, void *arg) return device_online(&mem->dev); } +static inline unsigned long memory_block_memmap_size(void) +{ + return PHYS_PFN(memory_block_size_bytes()) * sizeof(struct page); +} + +#ifndef arch_supports_memmap_on_memory +static inline bool arch_supports_memmap_on_memory(unsigned long vmemmap_size) +{ + /* + * As default, we want the vmemmap to span a complete PMD such that we + * can map the vmemmap using a single PMD if supported by the + * architecture. + */ + return IS_ALIGNED(vmemmap_size, PMD_SIZE); +} +#endif + static bool mhp_supports_memmap_on_memory(unsigned long size) { - unsigned long nr_vmemmap_pages = size / PAGE_SIZE; - unsigned long vmemmap_size = nr_vmemmap_pages * sizeof(struct page); + unsigned long vmemmap_size = memory_block_memmap_size(); unsigned long remaining_size = size - vmemmap_size; /*
@@ -1281,8 +1297,8 @@ static bool mhp_supports_memmap_on_memory(unsigned long size) */ return mhp_memmap_on_memory() && size == memory_block_size_bytes() && - IS_ALIGNED(vmemmap_size, PMD_SIZE) && - IS_ALIGNED(remaining_size, (pageblock_nr_pages << PAGE_SHIFT)); + IS_ALIGNED(remaining_size, (pageblock_nr_pages << PAGE_SHIFT)) && + arch_supports_memmap_on_memory(vmemmap_size); } /*
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2.41.0