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x86/acpi: Replace manual page table initialization with kernel_ident_mapping_init()

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The init_transition_pgtable() functions maps the page with
asm_acpi_mp_play_dead() into an identity mapping.

Replace open-coded manual page table initialization with
kernel_ident_mapping_init() to avoid code duplication.

Use x86_mapping_info::offset to get the page mapped at the
correct location.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Kai Huang <kai.huang@intel.com>
Reviewed-by: Tom Lendacky <thomas.lendacky@amd.com>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: https://lore.kernel.org/r/20241016111458.846228-3-kirill.shutemov@linux.intel.com
This commit is contained in:
Kirill A. Shutemov
2024-10-16 14:14:56 +03:00
committed by Ingo Molnar
parent 634ab76159
commit 775d37d8f0
1 changed files with 15 additions and 58 deletions
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73
arch/x86/kernel/acpi/madt_wakeup.c
View File

@@ -70,58 +70,6 @@ static void __init free_pgt_page(void *pgt, void *dummy)
return memblock_free(pgt, PAGE_SIZE);
}
/*
* Make sure asm_acpi_mp_play_dead() is present in the identity mapping at
* the same place as in the kernel page tables. asm_acpi_mp_play_dead() switches
* to the identity mapping and the function has be present at the same spot in
* the virtual address space before and after switching page tables.
*/
static int __init init_transition_pgtable(pgd_t *pgd)
{
pgprot_t prot = PAGE_KERNEL_EXEC_NOENC;
unsigned long vaddr, paddr;
p4d_t *p4d;
pud_t *pud;
pmd_t *pmd;
pte_t *pte;
vaddr = (unsigned long)asm_acpi_mp_play_dead;
pgd += pgd_index(vaddr);
if (!pgd_present(*pgd)) {
p4d = (p4d_t *)alloc_pgt_page(NULL);
if (!p4d)
return -ENOMEM;
set_pgd(pgd, __pgd(__pa(p4d) | _KERNPG_TABLE));
}
p4d = p4d_offset(pgd, vaddr);
if (!p4d_present(*p4d)) {
pud = (pud_t *)alloc_pgt_page(NULL);
if (!pud)
return -ENOMEM;
set_p4d(p4d, __p4d(__pa(pud) | _KERNPG_TABLE));
}
pud = pud_offset(p4d, vaddr);
if (!pud_present(*pud)) {
pmd = (pmd_t *)alloc_pgt_page(NULL);
if (!pmd)
return -ENOMEM;
set_pud(pud, __pud(__pa(pmd) | _KERNPG_TABLE));
}
pmd = pmd_offset(pud, vaddr);
if (!pmd_present(*pmd)) {
pte = (pte_t *)alloc_pgt_page(NULL);
if (!pte)
return -ENOMEM;
set_pmd(pmd, __pmd(__pa(pte) | _KERNPG_TABLE));
}
pte = pte_offset_kernel(pmd, vaddr);
paddr = __pa(vaddr);
set_pte(pte, pfn_pte(paddr >> PAGE_SHIFT, prot));
return 0;
}
static int __init acpi_mp_setup_reset(u64 reset_vector)
{
struct x86_mapping_info info = {
@@ -130,6 +78,7 @@ static int __init acpi_mp_setup_reset(u64 reset_vector)
.page_flag = __PAGE_KERNEL_LARGE_EXEC,
.kernpg_flag = _KERNPG_TABLE_NOENC,
};
unsigned long mstart, mend;
pgd_t *pgd;
pgd = alloc_pgt_page(NULL);
@@ -137,8 +86,6 @@ static int __init acpi_mp_setup_reset(u64 reset_vector)
return -ENOMEM;
for (int i = 0; i < nr_pfn_mapped; i++) {
unsigned long mstart, mend;
mstart = pfn_mapped[i].start << PAGE_SHIFT;
mend = pfn_mapped[i].end << PAGE_SHIFT;
if (kernel_ident_mapping_init(&info, pgd, mstart, mend)) {
@@ -147,14 +94,24 @@ static int __init acpi_mp_setup_reset(u64 reset_vector)
}
}
if (kernel_ident_mapping_init(&info, pgd,
PAGE_ALIGN_DOWN(reset_vector),
PAGE_ALIGN(reset_vector + 1))) {
mstart = PAGE_ALIGN_DOWN(reset_vector);
mend = mstart + PAGE_SIZE;
if (kernel_ident_mapping_init(&info, pgd, mstart, mend)) {
kernel_ident_mapping_free(&info, pgd);
return -ENOMEM;
}
if (init_transition_pgtable(pgd)) {
/*
* Make sure asm_acpi_mp_play_dead() is present in the identity mapping
* at the same place as in the kernel page tables.
* asm_acpi_mp_play_dead() switches to the identity mapping and the
* function must be present at the same spot in the virtual address space
* before and after switching page tables.
*/
info.offset = __START_KERNEL_map - phys_base;
mstart = PAGE_ALIGN_DOWN(__pa(asm_acpi_mp_play_dead));
mend = mstart + PAGE_SIZE;
if (kernel_ident_mapping_init(&info, pgd, mstart, mend)) {
kernel_ident_mapping_free(&info, pgd);
return -ENOMEM;
}