x86/boot/e820: Simplify the e820__update_table() interface

The e820__update_table() parameters are pretty complex:

  arch/x86/include/asm/e820/api.h:extern int  e820__update_table(struct e820_entry *biosmap, int max_nr_map, u32 *pnr_map);

But 90% of the usage is trivial:

  arch/x86/kernel/e820.c:	if (e820__update_table(e820_table->entries, ARRAY_SIZE(e820_table->entries), &e820_table->nr_entries))
  arch/x86/kernel/e820.c:	e820__update_table(e820_table->entries, ARRAY_SIZE(e820_table->entries), &e820_table->nr_entries);
  arch/x86/kernel/e820.c:	e820__update_table(e820_table->entries, ARRAY_SIZE(e820_table->entries), &e820_table->nr_entries);
  arch/x86/kernel/e820.c:		if (e820__update_table(e820_table->entries, ARRAY_SIZE(e820_table->entries), &e820_table->nr_entries) < 0)
  arch/x86/kernel/e820.c:	e820__update_table(boot_params.e820_table, ARRAY_SIZE(boot_params.e820_table), &new_nr);
  arch/x86/kernel/early-quirks.c:	e820__update_table(e820_table->entries, ARRAY_SIZE(e820_table->entries), &e820_table->nr_entries);
  arch/x86/kernel/setup.c:	e820__update_table(e820_table->entries, ARRAY_SIZE(e820_table->entries), &e820_table->nr_entries);
  arch/x86/kernel/setup.c:		e820__update_table(e820_table->entries, ARRAY_SIZE(e820_table->entries), &e820_table->nr_entries);
  arch/x86/platform/efi/efi.c:	e820__update_table(e820_table->entries, ARRAY_SIZE(e820_table->entries), &e820_table->nr_entries);
  arch/x86/xen/setup.c:	e820__update_table(xen_e820_table.entries, ARRAY_SIZE(xen_e820_table.entries),
  arch/x86/xen/setup.c:	e820__update_table(e820_table->entries, ARRAY_SIZE(e820_table->entries), &e820_table->nr_entries);
  arch/x86/xen/setup.c:	e820__update_table(xen_e820_table.entries, ARRAY_SIZE(xen_e820_table.entries),

as it only uses an exiting struct e820_table's entries array, its size and
its current number of entries as input and output arguments.

Only one use is non-trivial:

  arch/x86/kernel/e820.c:	e820__update_table(boot_params.e820_table, ARRAY_SIZE(boot_params.e820_table), &new_nr);

... which call updates the E820 table in the zeropage in-situ, and the layout there does not
match that of 'struct e820_table' (in particular nr_entries is at a different offset,
hardcoded by the boot protocol).

Simplify all this by introducing a low level __e820__update_table() API that
the zeropage update call can use, and simplifying the main e820__update_table()
call signature down to:

	int e820__update_table(struct e820_table *table);

This visibly simplifies all the call sites:

  arch/x86/include/asm/e820/api.h:extern int  e820__update_table(struct e820_table *table);
  arch/x86/include/asm/e820/types.h: * call to e820__update_table() to remove duplicates.  The allowance
  arch/x86/kernel/e820.c: * The return value from e820__update_table() is zero if it
  arch/x86/kernel/e820.c:int __init e820__update_table(struct e820_table *table)
  arch/x86/kernel/e820.c:	if (e820__update_table(e820_table))
  arch/x86/kernel/e820.c:	e820__update_table(e820_table_firmware);
  arch/x86/kernel/e820.c:	e820__update_table(e820_table);
  arch/x86/kernel/e820.c:	e820__update_table(e820_table);
  arch/x86/kernel/e820.c:		if (e820__update_table(e820_table) < 0)
  arch/x86/kernel/early-quirks.c:	e820__update_table(e820_table);
  arch/x86/kernel/setup.c:	e820__update_table(e820_table);
  arch/x86/kernel/setup.c:		e820__update_table(e820_table);
  arch/x86/platform/efi/efi.c:	e820__update_table(e820_table);
  arch/x86/xen/setup.c:	e820__update_table(&xen_e820_table);
  arch/x86/xen/setup.c:	e820__update_table(e820_table);
  arch/x86/xen/setup.c:	e820__update_table(&xen_e820_table);

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>
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c
index cf29abf..a5bf7c4 100644
--- a/arch/x86/xen/setup.c
+++ b/arch/x86/xen/setup.c
@@ -782,7 +782,7 @@ char * __init xen_memory_setup(void)
 		xen_ignore_unusable();
 
 	/* Make sure the Xen-supplied memory map is well-ordered. */
-	e820__update_table(xen_e820_table.entries, ARRAY_SIZE(xen_e820_table.entries), &xen_e820_table.nr_entries);
+	e820__update_table(&xen_e820_table);
 
 	max_pages = xen_get_max_pages();
 
@@ -856,10 +856,9 @@ char * __init xen_memory_setup(void)
 	 * reserve ISA memory anyway because too many things poke
 	 * about in there.
 	 */
-	e820__range_add(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS,
-			E820_TYPE_RESERVED);
+	e820__range_add(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS, E820_TYPE_RESERVED);
 
-	e820__update_table(e820_table->entries, ARRAY_SIZE(e820_table->entries), &e820_table->nr_entries);
+	e820__update_table(e820_table);
 
 	/*
 	 * Check whether the kernel itself conflicts with the target E820 map.
@@ -930,7 +929,7 @@ char * __init xen_auto_xlated_memory_setup(void)
 
 	xen_e820_table.nr_entries = memmap.nr_entries;
 
-	e820__update_table(xen_e820_table.entries, ARRAY_SIZE(xen_e820_table.entries), &xen_e820_table.nr_entries);
+	e820__update_table(&xen_e820_table);
 
 	for (i = 0; i < xen_e820_table.nr_entries; i++)
 		e820__range_add(xen_e820_table.entries[i].addr, xen_e820_table.entries[i].size, xen_e820_table.entries[i].type);