arm64: kdump: Remove custom linux,elfcorehdr handling

Remove the architecture-specific code for handling the
"linux,elfcorehdr" property under the "/chosen" node in DT, as the
platform-agnostic handling in the FDT core code already takes care of
this.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/3b8f801f9b92066855e87f3079fafc153ab20f69.1628670468.git.geert+renesas@glider.be

arch/arm64/mm/init.c

@@ -124,57 +124,6 @@ static void __init reserve_crashkernel(void)
 }
 #endif /* CONFIG_KEXEC_CORE */
 
-#ifdef CONFIG_CRASH_DUMP
-static int __init early_init_dt_scan_elfcorehdr(unsigned long node,
-		const char *uname, int depth, void *data)
-{
-	const __be32 *reg;
-	int len;
-
-	if (depth != 1 || strcmp(uname, "chosen") != 0)
-		return 0;
-
-	reg = of_get_flat_dt_prop(node, "linux,elfcorehdr", &len);
-	if (!reg || (len < (dt_root_addr_cells + dt_root_size_cells)))
-		return 1;
-
-	elfcorehdr_addr = dt_mem_next_cell(dt_root_addr_cells, &reg);
-	elfcorehdr_size = dt_mem_next_cell(dt_root_size_cells, &reg);
-
-	return 1;
-}
-
-/*
- * reserve_elfcorehdr() - reserves memory for elf core header
- *
- * This function reserves the memory occupied by an elf core header
- * described in the device tree. This region contains all the
- * information about primary kernel's core image and is used by a dump
- * capture kernel to access the system memory on primary kernel.
- */
-static void __init reserve_elfcorehdr(void)
-{
-	of_scan_flat_dt(early_init_dt_scan_elfcorehdr, NULL);
-
-	if (!elfcorehdr_size)
-		return;
-
-	if (memblock_is_region_reserved(elfcorehdr_addr, elfcorehdr_size)) {
-		pr_warn("elfcorehdr is overlapped\n");
-		return;
-	}
-
-	memblock_reserve(elfcorehdr_addr, elfcorehdr_size);
-
-	pr_info("Reserving %lldKB of memory at 0x%llx for elfcorehdr\n",
-		elfcorehdr_size >> 10, elfcorehdr_addr);
-}
-#else
-static void __init reserve_elfcorehdr(void)
-{
-}
-#endif /* CONFIG_CRASH_DUMP */
-
 /*
  * Return the maximum physical address for a zone accessible by the given bits
  * limit. If DRAM starts above 32-bit, expand the zone to the maximum
@@ -395,8 +344,6 @@ void __init arm64_memblock_init(void)
 
 	early_init_fdt_scan_reserved_mem();
 
-	reserve_elfcorehdr();
-
 	high_memory = __va(memblock_end_of_DRAM() - 1) + 1;
 }