3 files changed, 20 insertions, 5 deletions

diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index e1ec947e7c0c..0c656850eeea 100644
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -332,6 +332,17 @@ static inline void *phys_to_virt(phys_addr_t x)
 #define virt_addr_valid(kaddr)          \
         (_virt_addr_is_linear(kaddr) && _virt_addr_valid(kaddr))
 
+/*
+ * Given that the GIC architecture permits ITS implementations that can only be
+ * configured with a LPI table address once, GICv3 systems with many CPUs may
+ * end up reserving a lot of different regions after a kexec for their LPI
+ * tables (one per CPU), as we are forced to reuse the same memory after kexec
+ * (and thus reserve it persistently with EFI beforehand)
+ */
+#if defined(CONFIG_EFI) && defined(CONFIG_ARM_GIC_V3_ITS)
+# define INIT_MEMBLOCK_RESERVED_REGIONS (INIT_MEMBLOCK_REGIONS + NR_CPUS + 1)
+#endif
+
 #include <asm-generic/memory_model.h>
 
 #endif
diff --git a/include/linux/memblock.h b/include/linux/memblock.h
index 64c41cf45590..859b55b66db2 100644
--- a/include/linux/memblock.h
+++ b/include/linux/memblock.h
@@ -29,9 +29,6 @@ extern unsigned long max_pfn;
  */
 extern unsigned long long max_possible_pfn;
 
-#define INIT_MEMBLOCK_REGIONS   128
-#define INIT_PHYSMEM_REGIONS    4
-
 /**
  * enum memblock_flags - definition of memory region attributes
  * @MEMBLOCK_NONE: no special request
diff --git a/mm/memblock.c b/mm/memblock.c
index 022d4cbb3618..ea31045ba704 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -26,6 +26,13 @@
 
 #include "internal.h"
 
+#define INIT_MEMBLOCK_REGIONS                   128
+#define INIT_PHYSMEM_REGIONS                    4
+
+#ifndef INIT_MEMBLOCK_RESERVED_REGIONS
+# define INIT_MEMBLOCK_RESERVED_REGIONS         INIT_MEMBLOCK_REGIONS
+#endif
+
 /**
  * DOC: memblock overview
  *
@@ -92,7 +99,7 @@ unsigned long max_pfn;
 unsigned long long max_possible_pfn;
 
 static struct memblock_region memblock_memory_init_regions[INIT_MEMBLOCK_REGIONS] __initdata_memblock;
-static struct memblock_region memblock_reserved_init_regions[INIT_MEMBLOCK_REGIONS] __initdata_memblock;
+static struct memblock_region memblock_reserved_init_regions[INIT_MEMBLOCK_RESERVED_REGIONS] __initdata_memblock;
 #ifdef CONFIG_HAVE_MEMBLOCK_PHYS_MAP
 static struct memblock_region memblock_physmem_init_regions[INIT_PHYSMEM_REGIONS] __initdata_memblock;
 #endif
@@ -105,7 +112,7 @@ struct memblock memblock __initdata_memblock = {
 
         .reserved.regions       = memblock_reserved_init_regions,
         .reserved.cnt           = 1,    /* empty dummy entry */
-        .reserved.max           = INIT_MEMBLOCK_REGIONS,
+        .reserved.max           = INIT_MEMBLOCK_RESERVED_REGIONS,
         .reserved.name          = "reserved",
 
 #ifdef CONFIG_HAVE_MEMBLOCK_PHYS_MAP