x86/boot/e820: Simplify the e820__range_remove() API

Right now e820__range_remove() has two parameters to control the
E820 type of the range removed:

	extern void e820__range_remove(u64 start, u64 size, enum e820_type old_type, bool check_type);

Since E820 types start at 1, zero has a natural meaning of 'no type.

Consolidate the (old_type,check_type) parameters into a single (filter_type)
parameter:

	extern void e820__range_remove(u64 start, u64 size, enum e820_type filter_type);

Note that both e820__mapped_raw_any() and e820__mapped_any()
already have such semantics for their 'type' parameter, although
it's currently not used with '0' by in-kernel code.

Also, the __e820__mapped_all() internal helper already has such
semantics implemented as well, and the e820__get_entry_type() API
uses the '0' type to such effect.

This simplifies not just e820__range_remove(), and synchronizes its
use of type filters with other E820 API functions, but simplifies
usage sites as well, such as parse_memmap_one(), beyond the reduction
of the number of parameters:

  -               else if (from)
  -                       e820__range_remove(start_at, mem_size, from, 1);
                  else
  -                       e820__range_remove(start_at, mem_size, 0, 0);
  +                       e820__range_remove(start_at, mem_size, from);

The generated code gets smaller as well:

	add/remove: 0/0 grow/shrink: 0/5 up/down: 0/-66 (-66)

	Function                                     old     new   delta
	parse_memopt                                 112     107      -5
	efi_init                                    1048    1039      -9
	setup_arch                                  2719    2709     -10
	e820__range_remove                           283     273     -10
	parse_memmap_opt                             559     527     -32

	Total: Before=22,675,600, After=22,675,534, chg -0.00%

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: H . Peter Anvin <hpa@zytor.com>
Cc: Andy Shevchenko <andy@kernel.org>
Cc: Arnd Bergmann <arnd@kernel.org>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Juergen Gross <jgross@suse.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Paul Menzel <pmenzel@molgen.mpg.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: https://patch.msgid.link/20250515120549.2820541-28-mingo@kernel.org

Author: ingomolnar

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

@@ -16,7 +16,7 @@ extern bool e820__mapped_all(u64 start, u64 end, enum e820_type type);
 
 extern void e820__range_add   (u64 start, u64 size, enum e820_type type);
 extern u64  e820__range_update(u64 start, u64 size, enum e820_type old_type, enum e820_type new_type);
-extern void e820__range_remove(u64 start, u64 size, enum e820_type old_type, bool check_type);
+extern void e820__range_remove(u64 start, u64 size, enum e820_type filter_type);
 extern u64  e820__range_update_table(struct e820_table *t, u64 start, u64 size, enum e820_type old_type, enum e820_type new_type);
 
 extern int  e820__update_table(struct e820_table *table);

arch/x86/kernel/e820.c

@@ -548,7 +548,7 @@ __init u64 e820__range_update_table(struct e820_table *t, u64 start, u64 size,
 }
 
 /* Remove a range of memory from the E820 table: */
-__init void e820__range_remove(u64 start, u64 size, enum e820_type old_type, bool check_type)
+__init void e820__range_remove(u64 start, u64 size, enum e820_type filter_type)
 {
 	u32 idx;
 	u64 end;
@@ -558,16 +558,16 @@ __init void e820__range_remove(u64 start, u64 size, enum e820_type old_type, boo
 
 	end = start + size;
 	printk(KERN_DEBUG "e820: remove [mem %#010Lx-%#010Lx]", start, end - 1);
-	if (check_type)
-		e820_print_type(old_type);
+	if (filter_type)
+		e820_print_type(filter_type);
 	pr_cont("\n");
 
 	for (idx = 0; idx < e820_table->nr_entries; idx++) {
 		struct e820_entry *entry = &e820_table->entries[idx];
 		u64 final_start, final_end;
 		u64 entry_end;
 
-		if (check_type && entry->type != old_type)
+		if (filter_type && entry->type != filter_type)
 			continue;
 
 		entry_end = entry->addr + entry->size;
@@ -903,7 +903,7 @@ __init static int parse_memopt(char *p)
 	if (mem_size == 0)
 		return -EINVAL;
 
-	e820__range_remove(mem_size, ULLONG_MAX - mem_size, E820_TYPE_RAM, 1);
+	e820__range_remove(mem_size, ULLONG_MAX - mem_size, E820_TYPE_RAM);
 
 #ifdef CONFIG_MEMORY_HOTPLUG
 	max_mem_size = mem_size;
@@ -959,12 +959,10 @@ __init static int parse_memmap_one(char *p)
 			e820__range_update(start_at, mem_size, from, to);
 		else if (to)
 			e820__range_add(start_at, mem_size, to);
-		else if (from)
-			e820__range_remove(start_at, mem_size, from, 1);
 		else
-			e820__range_remove(start_at, mem_size, 0, 0);
+			e820__range_remove(start_at, mem_size, from);
 	} else {
-		e820__range_remove(mem_size, ULLONG_MAX - mem_size, E820_TYPE_RAM, 1);
+		e820__range_remove(mem_size, ULLONG_MAX - mem_size, E820_TYPE_RAM);
 	}
 
 	return *p == '\0' ? 0 : -EINVAL;

arch/x86/kernel/setup.c

@@ -763,7 +763,7 @@ static void __init trim_bios_range(void)
 	 * area (640Kb -> 1Mb) as RAM even though it is not.
 	 * take them out.
 	 */
-	e820__range_remove(BIOS_BEGIN, BIOS_END - BIOS_BEGIN, E820_TYPE_RAM, 1);
+	e820__range_remove(BIOS_BEGIN, BIOS_END - BIOS_BEGIN, E820_TYPE_RAM);
 
 	e820__update_table(e820_table);
 }
@@ -785,7 +785,7 @@ static void __init e820_add_kernel_range(void)
 		return;
 
 	pr_warn(".text .data .bss are not marked as E820_TYPE_RAM!\n");
-	e820__range_remove(start, size, E820_TYPE_RAM, 0);
+	e820__range_remove(start, size, 0);
 	e820__range_add(start, size, E820_TYPE_RAM);
 }
 

arch/x86/platform/efi/efi.c

@@ -333,8 +333,7 @@ static void __init efi_remove_e820_mmio(void)
 			if (size >= 256*1024) {
 				pr_info("Remove mem%02u: MMIO range=[0x%08llx-0x%08llx] (%lluMB) from e820 map\n",
 					i, start, end, size >> 20);
-				e820__range_remove(start, size,
-						   E820_TYPE_RESERVED, 1);
+				e820__range_remove(start, size, E820_TYPE_RESERVED);
 			} else {
 				pr_info("Not removing mem%02u: MMIO range=[0x%08llx-0x%08llx] (%lluKB) from e820 map\n",
 					i, start, end, size >> 10);