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authorSumanth Korikkar <sumanthk@linux.ibm.com>2023-11-20 15:53:54 +0100
committerAndrew Morton <akpm@linux-foundation.org>2023-12-10 16:51:48 -0800
commit95a2ac937013cc3aaaea02abcdd167b96874548d (patch)
tree75ab956543051fed58270c28c1b1c34d19c75c4f /include/linux/mm.h
parentbd9d9624b7136b69d892597b6a8cc482341e415a (diff)
mm: use vmem_altmap code without CONFIG_ZONE_DEVICE
vmem_altmap_free() and vmem_altmap_offset() could be utlized without CONFIG_ZONE_DEVICE enabled. For example, mm/memory_hotplug.c:__add_pages() relies on that. The altmap is no longer restricted to ZONE_DEVICE handling, but instead depends on CONFIG_SPARSEMEM_VMEMMAP. When CONFIG_SPARSEMEM_VMEMMAP is disabled, these functions are defined as inline stubs, ensuring compatibility with configurations that do not use sparsemem vmemmap. Without it, lkp reported the following: ld: arch/x86/mm/init_64.o: in function `remove_pagetable': init_64.c:(.meminit.text+0xfc7): undefined reference to `vmem_altmap_free' Link: https://lkml.kernel.org/r/20231120145354.308999-4-sumanthk@linux.ibm.com Signed-off-by: Sumanth Korikkar <sumanthk@linux.ibm.com> Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202311180545.VeyRXEDq-lkp@intel.com/ Reviewed-by: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Diffstat (limited to 'include/linux/mm.h')
-rw-r--r--include/linux/mm.h26
1 files changed, 26 insertions, 0 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 13a090271716..a422cc123a2d 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -3871,6 +3871,32 @@ void vmemmap_free(unsigned long start, unsigned long end,
struct vmem_altmap *altmap);
#endif
+#ifdef CONFIG_SPARSEMEM_VMEMMAP
+static inline unsigned long vmem_altmap_offset(struct vmem_altmap *altmap)
+{
+ /* number of pfns from base where pfn_to_page() is valid */
+ if (altmap)
+ return altmap->reserve + altmap->free;
+ return 0;
+}
+
+static inline void vmem_altmap_free(struct vmem_altmap *altmap,
+ unsigned long nr_pfns)
+{
+ altmap->alloc -= nr_pfns;
+}
+#else
+static inline unsigned long vmem_altmap_offset(struct vmem_altmap *altmap)
+{
+ return 0;
+}
+
+static inline void vmem_altmap_free(struct vmem_altmap *altmap,
+ unsigned long nr_pfns)
+{
+}
+#endif
+
#define VMEMMAP_RESERVE_NR 2
#ifdef CONFIG_ARCH_WANT_OPTIMIZE_DAX_VMEMMAP
static inline bool __vmemmap_can_optimize(struct vmem_altmap *altmap,