x86/setup: consolidate early memory reservations

index 3412c4595efd..3b582406363a 100644
@@ -646,18 +646,6 @@ static void __init trim_snb_memory(void)
 	}
 }
 
-/*
- * Here we put platform-specific memory range workarounds, i.e.
- * memory known to be corrupt or otherwise in need to be reserved on
- * specific platforms.
- *
- * If this gets used more widely it could use a real dispatch mechanism.
- */
-static void __init trim_platform_memory_ranges(void)
-{
-	trim_snb_memory();
-}
-
 static void __init trim_bios_range(void)
 {
 	/*

@@ -728,7 +716,38 @@ static void __init trim_low_memory_range(void)
 	 */
 	memblock_reserve(0, ALIGN(reserve_low, PAGE_SIZE));
 }
-	
+
+static void __init early_reserve_memory(void)
+{
+	/*
+	 * Reserve the memory occupied by the kernel between _text and
+	 * __end_of_kernel_reserve symbols. Any kernel sections after the
+	 * __end_of_kernel_reserve symbol must be explicitly reserved with a
+	 * separate memblock_reserve() or they will be discarded.
+	 */
+	memblock_reserve(__pa_symbol(_text),
+			 (unsigned long)__end_of_kernel_reserve - (unsigned long)_text);
+
+	/*
+	 * Make sure page 0 is always reserved because on systems with
+	 * L1TF its contents can be leaked to user processes.
+	 */
+	memblock_reserve(0, PAGE_SIZE);
+
+	early_reserve_initrd();
+
+	if (efi_enabled(EFI_BOOT))
+		efi_memblock_x86_reserve_range();
+
+	memblock_x86_reserve_range_setup_data();
+
+	reserve_ibft_region();
+	reserve_bios_regions();
+
+	trim_snb_memory();
+	trim_low_memory_range();
+}
+
 /*
  * Dump out kernel offset information on panic.
  */

@@ -763,29 +782,6 @@ dump_kernel_offset(struct notifier_block *self, unsigned long v, void *p)
 
 void __init setup_arch(char **cmdline_p)
 {
-	/*
-	 * Reserve the memory occupied by the kernel between _text and
-	 * __end_of_kernel_reserve symbols. Any kernel sections after the
-	 * __end_of_kernel_reserve symbol must be explicitly reserved with a
-	 * separate memblock_reserve() or they will be discarded.
-	 */
-	memblock_reserve(__pa_symbol(_text),
-			 (unsigned long)__end_of_kernel_reserve - (unsigned long)_text);
-
-	/*
-	 * Make sure page 0 is always reserved because on systems with
-	 * L1TF its contents can be leaked to user processes.
-	 */
-	memblock_reserve(0, PAGE_SIZE);
-
-	early_reserve_initrd();
-
-	/*
-	 * At this point everything still needed from the boot loader
-	 * or BIOS or kernel text should be early reserved or marked not
-	 * RAM in e820. All other memory is free game.
-	 */
-
 #ifdef CONFIG_X86_32
 	memcpy(&boot_cpu_data, &new_cpu_data, sizeof(new_cpu_data));
 

@@ -909,8 +905,18 @@ void __init setup_arch(char **cmdline_p)
 
 	parse_early_param();
 
-	if (efi_enabled(EFI_BOOT))
-		efi_memblock_x86_reserve_range();
+	/*
+	 * Do some memory reservations *before* memory is added to
+	 * memblock, so memblock allocations won't overwrite it.
+	 * Do it after early param, so we could get (unlikely) panic from
+	 * serial.
+	 *
+	 * After this point everything still needed from the boot loader or
+	 * firmware or kernel text should be early reserved or marked not
+	 * RAM in e820. All other memory is free game.
+	 */
+	early_reserve_memory();
+
 #ifdef CONFIG_MEMORY_HOTPLUG
 	/*
 	 * Memory used by the kernel cannot be hot-removed because Linux

@@ -937,9 +943,6 @@ void __init setup_arch(char **cmdline_p)
 
 	x86_report_nx();
 
-	/* after early param, so could get panic from serial */
-	memblock_x86_reserve_range_setup_data();
-
 	if (acpi_mps_check()) {
 #ifdef CONFIG_X86_LOCAL_APIC
 		disable_apic = 1;

@@ -1031,8 +1034,6 @@ void __init setup_arch(char **cmdline_p)
 	 */
 	find_smp_config();
 
-	reserve_ibft_region();
-
 	early_alloc_pgt_buf();
 
 	/*

@@ -1053,8 +1054,6 @@ void __init setup_arch(char **cmdline_p)
 	 */
 	sev_setup_arch();
 
-	reserve_bios_regions();
-
 	efi_fake_memmap();
 	efi_find_mirror();
 	efi_esrt_init();

@@ -1080,9 +1079,6 @@ void __init setup_arch(char **cmdline_p)
 
 	reserve_real_mode();
 
-	trim_platform_memory_ranges();
-	trim_low_memory_range();
-
 	init_mem_mapping();
 
 	idt_setup_early_pf();

index 3b582406363a..b36624e3dc9e 100644
@@ -703,20 +703,6 @@ static int __init parse_reservelow(char *p)
 
 early_param("reservelow", parse_reservelow);
 
-static void __init trim_low_memory_range(void)
-{
-	/*
-	 * A special case is the first 4Kb of memory;
-	 * This is a BIOS owned area, not kernel ram, but generally
-	 * not listed as such in the E820 table.
-	 *
-	 * This typically reserves additional memory (64KiB by default)
-	 * since some BIOSes are known to corrupt low memory.  See the
-	 * Kconfig help text for X86_RESERVE_LOW.
-	 */
-	memblock_reserve(0, ALIGN(reserve_low, PAGE_SIZE));
-}
-
 static void __init early_reserve_memory(void)
 {
 	/*

@@ -729,10 +715,17 @@ static void __init early_reserve_memory(void)
 			 (unsigned long)__end_of_kernel_reserve - (unsigned long)_text);
 
 	/*
-	 * Make sure page 0 is always reserved because on systems with
-	 * L1TF its contents can be leaked to user processes.
+	 * The first 4Kb of memory is a BIOS owned area, but generally it is
+	 * not listed as such in the E820 table.
+	 *
+	 * Reserve the first memory page and typically some additional
+	 * memory (64KiB by default) since some BIOSes are known to corrupt
+	 * low memory. See the Kconfig help text for X86_RESERVE_LOW.
+	 *
+	 * In addition, make sure page 0 is always reserved because on
+	 * systems with L1TF its contents can be leaked to user processes.
 	 */
-	memblock_reserve(0, PAGE_SIZE);
+	memblock_reserve(0, ALIGN(reserve_low, PAGE_SIZE));
 
 	early_reserve_initrd();
 

@@ -745,7 +738,6 @@ static void __init early_reserve_memory(void)
 	reserve_bios_regions();
 
 	trim_snb_memory();
-	trim_low_memory_range();
 }
 
 /*