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Commit 45478336 authored by Kirill A. Shutemov's avatar Kirill A. Shutemov Committed by Ingo Molnar
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x86/mm/pat: Add 5-level paging support 



Straight-forward extension of existing code to support additional page
table level.

Signed-off-by: default avatarKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: default avatarThomas Gleixner <tglx@linutronix.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: linux-arch@vger.kernel.org
Cc: linux-mm@kvack.org
Link: http://lkml.kernel.org/r/20170317185515.8636-4-kirill.shutemov@linux.intel.com


Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent e981316f

arch/x86/mm/pageattr.c

+40 −14
Original line number Diff line number Diff line
@@ -346,6 +346,7 @@ static inline pgprot_t static_protections(pgprot_t prot, unsigned long address, 
pte_t *lookup_address_in_pgd(pgd_t *pgd, unsigned long address,

			     unsigned int *level)

{

	p4d_t *p4d;

	pud_t *pud;

	pmd_t *pmd;
@@ -354,7 +355,15 @@ pte_t *lookup_address_in_pgd(pgd_t *pgd, unsigned long address, 
	if (pgd_none(*pgd))

		return NULL;



	pud = pud_offset(pgd, address);

	p4d = p4d_offset(pgd, address);

	if (p4d_none(*p4d))

		return NULL;



	*level = PG_LEVEL_512G;

	if (p4d_large(*p4d) || !p4d_present(*p4d))

		return (pte_t *)p4d;



	pud = pud_offset(p4d, address);

	if (pud_none(*pud))

		return NULL;
@@ -406,13 +415,18 @@ static pte_t *_lookup_address_cpa(struct cpa_data *cpa, unsigned long address, 
pmd_t *lookup_pmd_address(unsigned long address)

{

	pgd_t *pgd;

	p4d_t *p4d;

	pud_t *pud;



	pgd = pgd_offset_k(address);

	if (pgd_none(*pgd))

		return NULL;



	pud = pud_offset(pgd, address);

	p4d = p4d_offset(pgd, address);

	if (p4d_none(*p4d) || p4d_large(*p4d) || !p4d_present(*p4d))

		return NULL;



	pud = pud_offset(p4d, address);

	if (pud_none(*pud) || pud_large(*pud) || !pud_present(*pud))

		return NULL;
@@ -477,11 +491,13 @@ static void __set_pmd_pte(pte_t *kpte, unsigned long address, pte_t pte) 


		list_for_each_entry(page, &pgd_list, lru) {

			pgd_t *pgd;

			p4d_t *p4d;

			pud_t *pud;

			pmd_t *pmd;



			pgd = (pgd_t *)page_address(page) + pgd_index(address);

			pud = pud_offset(pgd, address);

			p4d = p4d_offset(pgd, address);

			pud = pud_offset(p4d, address);

			pmd = pmd_offset(pud, address);

			set_pte_atomic((pte_t *)pmd, pte);

		}
@@ -836,9 +852,9 @@ static void unmap_pmd_range(pud_t *pud, unsigned long start, unsigned long end) 
			pud_clear(pud);

}



static void unmap_pud_range(pgd_t *pgd, unsigned long start, unsigned long end)

static void unmap_pud_range(p4d_t *p4d, unsigned long start, unsigned long end)

{

	pud_t *pud = pud_offset(pgd, start);

	pud_t *pud = pud_offset(p4d, start);



	/*

	 * Not on a GB page boundary?
@@ -1004,7 +1020,7 @@ static long populate_pmd(struct cpa_data *cpa, 
	return num_pages;

}



static long populate_pud(struct cpa_data *cpa, unsigned long start, pgd_t *pgd,

static int populate_pud(struct cpa_data *cpa, unsigned long start, p4d_t *p4d,

			pgprot_t pgprot)

{

	pud_t *pud;
@@ -1026,7 +1042,7 @@ static long populate_pud(struct cpa_data *cpa, unsigned long start, pgd_t *pgd, 
		cur_pages = (pre_end - start) >> PAGE_SHIFT;

		cur_pages = min_t(int, (int)cpa->numpages, cur_pages);



		pud = pud_offset(pgd, start);

		pud = pud_offset(p4d, start);



		/*

		 * Need a PMD page?
@@ -1047,7 +1063,7 @@ static long populate_pud(struct cpa_data *cpa, unsigned long start, pgd_t *pgd, 
	if (cpa->numpages == cur_pages)

		return cur_pages;



	pud = pud_offset(pgd, start);

	pud = pud_offset(p4d, start);

	pud_pgprot = pgprot_4k_2_large(pgprot);



	/*
@@ -1067,7 +1083,7 @@ static long populate_pud(struct cpa_data *cpa, unsigned long start, pgd_t *pgd, 
	if (start < end) {

		long tmp;



		pud = pud_offset(pgd, start);

		pud = pud_offset(p4d, start);

		if (pud_none(*pud))

			if (alloc_pmd_page(pud))

				return -1;
@@ -1090,33 +1106,43 @@ static int populate_pgd(struct cpa_data *cpa, unsigned long addr) 
{

	pgprot_t pgprot = __pgprot(_KERNPG_TABLE);

	pud_t *pud = NULL;	/* shut up gcc */

	p4d_t *p4d;

	pgd_t *pgd_entry;

	long ret;



	pgd_entry = cpa->pgd + pgd_index(addr);



	if (pgd_none(*pgd_entry)) {

		p4d = (p4d_t *)get_zeroed_page(GFP_KERNEL | __GFP_NOTRACK);

		if (!p4d)

			return -1;



		set_pgd(pgd_entry, __pgd(__pa(p4d) | _KERNPG_TABLE));

	}



	/*

	 * Allocate a PUD page and hand it down for mapping.

	 */

	if (pgd_none(*pgd_entry)) {

	p4d = p4d_offset(pgd_entry, addr);

	if (p4d_none(*p4d)) {

		pud = (pud_t *)get_zeroed_page(GFP_KERNEL | __GFP_NOTRACK);

		if (!pud)

			return -1;



		set_pgd(pgd_entry, __pgd(__pa(pud) | _KERNPG_TABLE));

		set_p4d(p4d, __p4d(__pa(pud) | _KERNPG_TABLE));

	}



	pgprot_val(pgprot) &= ~pgprot_val(cpa->mask_clr);

	pgprot_val(pgprot) |=  pgprot_val(cpa->mask_set);



	ret = populate_pud(cpa, addr, pgd_entry, pgprot);

	ret = populate_pud(cpa, addr, p4d, pgprot);

	if (ret < 0) {

		/*

		 * Leave the PUD page in place in case some other CPU or thread

		 * already found it, but remove any useless entries we just

		 * added to it.

		 */

		unmap_pud_range(pgd_entry, addr,

		unmap_pud_range(p4d, addr,

				addr + (cpa->numpages << PAGE_SHIFT));

		return ret;

	}