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x86/e820: Drop obsolete E820_TYPE_RESERVED_KERN and related code

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E820_TYPE_RESERVED_KERN is a relict from the ancient history that was used
to early reserve setup_data, see:

  28bb223795 ("x86: move reserve_setup_data to setup.c")

Nowadays setup_data is anyway reserved in memblock and there is no point in
carrying E820_TYPE_RESERVED_KERN that behaves exactly like E820_TYPE_RAM
but only complicates the code.

A bonus for removing E820_TYPE_RESERVED_KERN is a small but measurable
speedup of 20 microseconds in init_mem_mappings() on a VM with 32GB or RAM.

Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20250214090651.3331663-5-rppt@kernel.org
This commit is contained in:
Mike Rapoport (Microsoft)
2025-02-14 11:06:51 +02:00
committed by Ingo Molnar
parent d45dd0a9b2
commit efe659ac01
6 changed files with 4 additions and 83 deletions
Download Patch File Download Diff File Expand all files Collapse all files

1
arch/x86/include/asm/e820/api.h
View File

@@ -29,7 +29,6 @@ extern unsigned long e820__end_of_low_ram_pfn(void);
extern u64 e820__memblock_alloc_reserved(u64 size, u64 align);
extern void e820__memblock_setup(void);
extern void e820__reserve_setup_data(void);
extern void e820__finish_early_params(void);
extern void e820__reserve_resources(void);
extern void e820__reserve_resources_late(void);

9
arch/x86/include/asm/e820/types.h
View File

@@ -35,15 +35,6 @@ enum e820_type {
* marking it with the IORES_DESC_SOFT_RESERVED designation.
*/
E820_TYPE_SOFT_RESERVED = 0xefffffff,
/*
* Reserved RAM used by the kernel itself if
* CONFIG_INTEL_TXT=y is enabled, memory of this type
* will be included in the S3 integrity calculation
* and so should not include any memory that the BIOS
* might alter over the S3 transition:
*/
E820_TYPE_RESERVED_KERN = 128,
};
/*

65
arch/x86/kernel/e820.c
View File

@@ -187,8 +187,7 @@ void __init e820__range_add(u64 start, u64 size, enum e820_type type)
static void __init e820_print_type(enum e820_type type)
{
switch (type) {
case E820_TYPE_RAM: /* Fall through: */
case E820_TYPE_RESERVED_KERN: pr_cont("usable"); break;
case E820_TYPE_RAM: pr_cont("usable"); break;
case E820_TYPE_RESERVED: pr_cont("reserved"); break;
case E820_TYPE_SOFT_RESERVED: pr_cont("soft reserved"); break;
case E820_TYPE_ACPI: pr_cont("ACPI data"); break;
@@ -764,7 +763,7 @@ void __init e820__register_nosave_regions(unsigned long limit_pfn)
pfn = PFN_DOWN(entry->addr + entry->size);
if (entry->type != E820_TYPE_RAM && entry->type != E820_TYPE_RESERVED_KERN)
if (entry->type != E820_TYPE_RAM)
register_nosave_region(PFN_UP(entry->addr), pfn);
if (pfn >= limit_pfn)
@@ -990,60 +989,6 @@ static int __init parse_memmap_opt(char *str)
}
early_param("memmap", parse_memmap_opt);
/*
* Reserve all entries from the bootloader's extensible data nodes list,
* because if present we are going to use it later on to fetch e820
* entries from it:
*/
void __init e820__reserve_setup_data(void)
{
struct setup_indirect *indirect;
struct setup_data *data;
u64 pa_data, pa_next;
u32 len;
pa_data = boot_params.hdr.setup_data;
if (!pa_data)
return;
while (pa_data) {
data = early_memremap(pa_data, sizeof(*data));
if (!data) {
pr_warn("e820: failed to memremap setup_data entry\n");
return;
}
len = sizeof(*data);
pa_next = data->next;
e820__range_update(pa_data, sizeof(*data)+data->len, E820_TYPE_RAM, E820_TYPE_RESERVED_KERN);
if (data->type == SETUP_INDIRECT) {
len += data->len;
early_memunmap(data, sizeof(*data));
data = early_memremap(pa_data, len);
if (!data) {
pr_warn("e820: failed to memremap indirect setup_data\n");
return;
}
indirect = (struct setup_indirect *)data->data;
if (indirect->type != SETUP_INDIRECT)
e820__range_update(indirect->addr, indirect->len,
E820_TYPE_RAM, E820_TYPE_RESERVED_KERN);
}
pa_data = pa_next;
early_memunmap(data, len);
}
e820__update_table(e820_table);
pr_info("extended physical RAM map:\n");
e820__print_table("reserve setup_data");
}
/*
* 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
@@ -1063,7 +1008,6 @@ void __init e820__finish_early_params(void)
static const char *__init e820_type_to_string(struct e820_entry *entry)
{
switch (entry->type) {
case E820_TYPE_RESERVED_KERN: /* Fall-through: */
case E820_TYPE_RAM: return "System RAM";
case E820_TYPE_ACPI: return "ACPI Tables";
case E820_TYPE_NVS: return "ACPI Non-volatile Storage";
@@ -1079,7 +1023,6 @@ static const char *__init e820_type_to_string(struct e820_entry *entry)
static unsigned long __init e820_type_to_iomem_type(struct e820_entry *entry)
{
switch (entry->type) {
case E820_TYPE_RESERVED_KERN: /* Fall-through: */
case E820_TYPE_RAM: return IORESOURCE_SYSTEM_RAM;
case E820_TYPE_ACPI: /* Fall-through: */
case E820_TYPE_NVS: /* Fall-through: */
@@ -1101,7 +1044,6 @@ static unsigned long __init e820_type_to_iores_desc(struct e820_entry *entry)
case E820_TYPE_PRAM: return IORES_DESC_PERSISTENT_MEMORY_LEGACY;
case E820_TYPE_RESERVED: return IORES_DESC_RESERVED;
case E820_TYPE_SOFT_RESERVED: return IORES_DESC_SOFT_RESERVED;
case E820_TYPE_RESERVED_KERN: /* Fall-through: */
case E820_TYPE_RAM: /* Fall-through: */
case E820_TYPE_UNUSABLE: /* Fall-through: */
default: return IORES_DESC_NONE;
@@ -1124,7 +1066,6 @@ static bool __init do_mark_busy(enum e820_type type, struct resource *res)
case E820_TYPE_PRAM:
case E820_TYPE_PMEM:
return false;
case E820_TYPE_RESERVED_KERN:
case E820_TYPE_RAM:
case E820_TYPE_ACPI:
case E820_TYPE_NVS:
@@ -1353,7 +1294,7 @@ void __init e820__memblock_setup(void)
if (entry->type == E820_TYPE_SOFT_RESERVED)
memblock_reserve(entry->addr, entry->size);
if (entry->type != E820_TYPE_RAM && entry->type != E820_TYPE_RESERVED_KERN)
if (entry->type != E820_TYPE_RAM)
continue;
memblock_add(entry->addr, entry->size);

1
arch/x86/kernel/setup.c
View File

@@ -895,7 +895,6 @@ void __init setup_arch(char **cmdline_p)
setup_clear_cpu_cap(X86_FEATURE_APIC);
}
e820__reserve_setup_data();
e820__finish_early_params();
if (efi_enabled(EFI_BOOT))

3
arch/x86/kernel/tboot.c
View File

@@ -200,8 +200,7 @@ static int tboot_setup_sleep(void)
tboot->num_mac_regions = 0;
for (i = 0; i < e820_table->nr_entries; i++) {
if ((e820_table->entries[i].type != E820_TYPE_RAM)
&& (e820_table->entries[i].type != E820_TYPE_RESERVED_KERN))
if (e820_table->entries[i].type != E820_TYPE_RAM)
continue;
add_mac_region(e820_table->entries[i].addr, e820_table->entries[i].size);

8
arch/x86/mm/init_64.c
View File

@@ -468,8 +468,6 @@ phys_pte_init(pte_t *pte_page, unsigned long paddr, unsigned long paddr_end,
if (!after_bootmem &&
!e820__mapped_any(paddr & PAGE_MASK, paddr_next,
E820_TYPE_RAM) &&
!e820__mapped_any(paddr & PAGE_MASK, paddr_next,
E820_TYPE_RESERVED_KERN) &&
!e820__mapped_any(paddr & PAGE_MASK, paddr_next,
E820_TYPE_ACPI))
set_pte_init(pte, __pte(0), init);
@@ -525,8 +523,6 @@ phys_pmd_init(pmd_t *pmd_page, unsigned long paddr, unsigned long paddr_end,
if (!after_bootmem &&
!e820__mapped_any(paddr & PMD_MASK, paddr_next,
E820_TYPE_RAM) &&
!e820__mapped_any(paddr & PMD_MASK, paddr_next,
E820_TYPE_RESERVED_KERN) &&
!e820__mapped_any(paddr & PMD_MASK, paddr_next,
E820_TYPE_ACPI))
set_pmd_init(pmd, __pmd(0), init);
@@ -614,8 +610,6 @@ phys_pud_init(pud_t *pud_page, unsigned long paddr, unsigned long paddr_end,
if (!after_bootmem &&
!e820__mapped_any(paddr & PUD_MASK, paddr_next,
E820_TYPE_RAM) &&
!e820__mapped_any(paddr & PUD_MASK, paddr_next,
E820_TYPE_RESERVED_KERN) &&
!e820__mapped_any(paddr & PUD_MASK, paddr_next,
E820_TYPE_ACPI))
set_pud_init(pud, __pud(0), init);
@@ -703,8 +697,6 @@ phys_p4d_init(p4d_t *p4d_page, unsigned long paddr, unsigned long paddr_end,
if (!after_bootmem &&
!e820__mapped_any(paddr & P4D_MASK, paddr_next,
E820_TYPE_RAM) &&
!e820__mapped_any(paddr & P4D_MASK, paddr_next,
E820_TYPE_RESERVED_KERN) &&
!e820__mapped_any(paddr & P4D_MASK, paddr_next,
E820_TYPE_ACPI))
set_p4d_init(p4d, __p4d(0), init);