From 4547833602fdd3b672c9b945818cc658d38bfcf1 Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" Date: Fri, 17 Mar 2017 21:55:12 +0300 Subject: [PATCH] x86/mm/pat: Add 5-level paging support Straight-forward extension of existing code to support additional page table level. Signed-off-by: Kirill A. Shutemov Reviewed-by: Thomas Gleixner Cc: Andrew Morton Cc: Andy Lutomirski Cc: Andy Lutomirski Cc: Arnd Bergmann Cc: Borislav Petkov Cc: Brian Gerst Cc: Dave Hansen Cc: Denys Vlasenko Cc: H. Peter Anvin Cc: Josh Poimboeuf Cc: Linus Torvalds Cc: Michal Hocko Cc: Peter Zijlstra 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: Ingo Molnar --- arch/x86/mm/pageattr.c | 54 +++++++++++++++++++++++++++++++----------- 1 file changed, 40 insertions(+), 14 deletions(-) diff --git a/arch/x86/mm/pageattr.c b/arch/x86/mm/pageattr.c index 28d42130243c..b5949017dead 100644 --- a/arch/x86/mm/pageattr.c +++ b/arch/x86/mm/pageattr.c @@ -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? @@ -1004,8 +1020,8 @@ 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, - pgprot_t pgprot) +static int populate_pud(struct cpa_data *cpa, unsigned long start, p4d_t *p4d, + pgprot_t pgprot) { pud_t *pud; unsigned long end; @@ -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; } -- 2.20.1