Commit 69ba866d authored by Thomas Gleixner's avatar Thomas Gleixner Committed by Borislav Petkov (AMD)
Browse files

x86/boot/32: Restructure mk_early_pgtbl_32() 



Prepare it for adding a temporary initrd mapping by splitting out the
actual map loop.

No functional change.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Signed-off-by: default avatarBorislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20231017211722.175910753@linutronix.de
parent a62f4ca1

arch/x86/kernel/head32.c

+23 −19
Original line number Diff line number Diff line
@@ -79,36 +79,41 @@ typedef pgd_t pl2_t; 
#define SET_PL2(val)		{ .pgd = (val), }

#endif



void __init __no_stack_protector mk_early_pgtbl_32(void)

static __init __no_stack_protector pte_t init_map(pte_t pte, pte_t **ptep, pl2_t **pl2p,

						  const unsigned long limit)

{

	/* Enough space to fit pagetables for the low memory linear map */

	const unsigned long limit = __pa_nodebug(_end) +

		(PAGE_TABLE_SIZE(LOWMEM_PAGES) << PAGE_SHIFT);

	pte_t pte, *ptep = (pte_t *)__pa_nodebug(__brk_base);

	pl2_t *pl2p = (pl2_t *)__pa_nodebug(pl2_base);

	unsigned long *ptr;

	int i;



	pte.pte = PTE_IDENT_ATTR;



	while ((pte.pte & PTE_PFN_MASK) < limit) {

		pl2_t pl2 = SET_PL2((unsigned long)ptep | PDE_IDENT_ATTR);



		*pl2p = pl2;

		pl2_t pl2 = SET_PL2((unsigned long)*ptep | PDE_IDENT_ATTR);

		int i;



		**pl2p = pl2;

		if (!IS_ENABLED(CONFIG_X86_PAE)) {

			/* Kernel PDE entry */

			*(pl2p +  ((PAGE_OFFSET >> PGDIR_SHIFT))) = pl2;

			*(*pl2p + ((PAGE_OFFSET >> PGDIR_SHIFT))) = pl2;

		}



		for (i = 0; i < PTRS_PER_PTE; i++) {

			*ptep = pte;

			**ptep = pte;

			pte.pte += PAGE_SIZE;

			ptep++;

			(*ptep)++;

		}

		pl2p++;

		(*pl2p)++;

	}

	return pte;

}



void __init __no_stack_protector mk_early_pgtbl_32(void)

{

	/* Enough space to fit pagetables for the low memory linear map */

	const unsigned long limit = __pa_nodebug(_end) +

		(PAGE_TABLE_SIZE(LOWMEM_PAGES) << PAGE_SHIFT);

	pte_t pte, *ptep = (pte_t *)__pa_nodebug(__brk_base);

	pl2_t *pl2p = (pl2_t *)__pa_nodebug(pl2_base);

	unsigned long *ptr;



	pte.pte = PTE_IDENT_ATTR;

	pte = init_map(pte, &ptep, &pl2p, limit);



	ptr = (unsigned long *)__pa_nodebug(&max_pfn_mapped);

	/* Can't use pte_pfn() since it's a call with CONFIG_PARAVIRT */

	*ptr = (pte.pte & PTE_PFN_MASK) >> PAGE_SHIFT;
@@ -116,4 +121,3 @@ void __init __no_stack_protector mk_early_pgtbl_32(void) 
	ptr = (unsigned long *)__pa_nodebug(&_brk_end);

	*ptr = (unsigned long)ptep + PAGE_OFFSET;

}