x86/boot/e820: Clarify the role of finish_e820_parsing() and rename it to e820__finish_early_params()

finish_e820_parsing() is closely related to parse_early_params(), but the
name does not tell us this clearly, so rename it to e820__finish_early_params().

Also add a few comments to explain what the function does.

No change in functionality.

Cc: Alex Thorlton <athorlton@sgi.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Huang, Ying <ying.huang@intel.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Juergen Gross <jgross@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Jackson <pj@sgi.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rafael J. Wysocki <rjw@sisk.pl>
Cc: Tejun Heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/include/asm/e820/api.h

@@ -23,7 +23,7 @@ extern unsigned long e820_end_of_low_ram_pfn(void);
 extern u64  early_reserve_e820(u64 sizet, u64 align);
 extern void e820__memblock_setup(void);
 extern void e820_reserve_setup_data(void);
-extern void finish_e820_parsing(void);
+extern void e820__finish_early_params(void);
 extern void e820_reserve_resources(void);
 extern void e820_reserve_resources_late(void);
 extern void e820__memory_setup(void);

arch/x86/kernel/e820.c

@@ -932,7 +932,12 @@ void __init e820_reserve_setup_data(void)
 	e820_print_map("reserve setup_data");
 }
 
-void __init finish_e820_parsing(void)
+/*
+ * Called after parse_early_param(), after early parameters (such as mem=)
+ * have been processed, in which case we already have an E820 table filled in
+ * via the parameter callback function(s), but it's not sorted and printed yet:
+ */
+void __init e820__finish_early_params(void)
 {
 	if (userdef) {
 		if (sanitize_e820_table(e820_table->entries, ARRAY_SIZE(e820_table->entries), &e820_table->nr_entries) < 0)

arch/x86/kernel/setup.c

@@ -1005,7 +1005,7 @@ void __init setup_arch(char **cmdline_p)
 
 	/* update the e820_table_firmware too */
 	e820_reserve_setup_data();
-	finish_e820_parsing();
+	e820__finish_early_params();
 
 	if (efi_enabled(EFI_BOOT))
 		efi_init();