From: Joerg Roedel <jroedel@xxxxxxx> Subject: mm/ioremap: track which page-table levels were modified Track at which levels in the page-table entries were modified by ioremap_page_range(). After the page-table has been modified, use that information do decide whether the new arch_sync_kernel_mappings() needs to be called. The iounmap path re-uses vunmap(), which has already been taken care of. Link: http://lkml.kernel.org/r/20200515140023.25469-4-joro@xxxxxxxxxx Signed-off-by: Joerg Roedel <jroedel@xxxxxxx> Acked-by: Andy Lutomirski <luto@xxxxxxxxxx> Acked-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx> Cc: Arnd Bergmann <arnd@xxxxxxxx> Cc: Christoph Hellwig <hch@xxxxxx> Cc: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Cc: "H . Peter Anvin" <hpa@xxxxxxxxx> Cc: Ingo Molnar <mingo@xxxxxxx> Cc: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxxxx> Cc: "Rafael J. Wysocki" <rjw@xxxxxxxxxxxxx> Cc: Steven Rostedt (VMware) <rostedt@xxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: Vlastimil Babka <vbabka@xxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- lib/ioremap.c | 46 +++++++++++++++++++++++++++++++--------------- 1 file changed, 31 insertions(+), 15 deletions(-) --- a/lib/ioremap.c~mm-ioremap-track-which-page-table-levels-were-modified +++ a/lib/ioremap.c @@ -61,13 +61,14 @@ static inline int ioremap_pmd_enabled(vo #endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */ static int ioremap_pte_range(pmd_t *pmd, unsigned long addr, - unsigned long end, phys_addr_t phys_addr, pgprot_t prot) + unsigned long end, phys_addr_t phys_addr, pgprot_t prot, + pgtbl_mod_mask *mask) { pte_t *pte; u64 pfn; pfn = phys_addr >> PAGE_SHIFT; - pte = pte_alloc_kernel(pmd, addr); + pte = pte_alloc_kernel_track(pmd, addr, mask); if (!pte) return -ENOMEM; do { @@ -75,6 +76,7 @@ static int ioremap_pte_range(pmd_t *pmd, set_pte_at(&init_mm, addr, pte, pfn_pte(pfn, prot)); pfn++; } while (pte++, addr += PAGE_SIZE, addr != end); + *mask |= PGTBL_PTE_MODIFIED; return 0; } @@ -101,21 +103,24 @@ static int ioremap_try_huge_pmd(pmd_t *p } static inline int ioremap_pmd_range(pud_t *pud, unsigned long addr, - unsigned long end, phys_addr_t phys_addr, pgprot_t prot) + unsigned long end, phys_addr_t phys_addr, pgprot_t prot, + pgtbl_mod_mask *mask) { pmd_t *pmd; unsigned long next; - pmd = pmd_alloc(&init_mm, pud, addr); + pmd = pmd_alloc_track(&init_mm, pud, addr, mask); if (!pmd) return -ENOMEM; do { next = pmd_addr_end(addr, end); - if (ioremap_try_huge_pmd(pmd, addr, next, phys_addr, prot)) + if (ioremap_try_huge_pmd(pmd, addr, next, phys_addr, prot)) { + *mask |= PGTBL_PMD_MODIFIED; continue; + } - if (ioremap_pte_range(pmd, addr, next, phys_addr, prot)) + if (ioremap_pte_range(pmd, addr, next, phys_addr, prot, mask)) return -ENOMEM; } while (pmd++, phys_addr += (next - addr), addr = next, addr != end); return 0; @@ -144,21 +149,24 @@ static int ioremap_try_huge_pud(pud_t *p } static inline int ioremap_pud_range(p4d_t *p4d, unsigned long addr, - unsigned long end, phys_addr_t phys_addr, pgprot_t prot) + unsigned long end, phys_addr_t phys_addr, pgprot_t prot, + pgtbl_mod_mask *mask) { pud_t *pud; unsigned long next; - pud = pud_alloc(&init_mm, p4d, addr); + pud = pud_alloc_track(&init_mm, p4d, addr, mask); if (!pud) return -ENOMEM; do { next = pud_addr_end(addr, end); - if (ioremap_try_huge_pud(pud, addr, next, phys_addr, prot)) + if (ioremap_try_huge_pud(pud, addr, next, phys_addr, prot)) { + *mask |= PGTBL_PUD_MODIFIED; continue; + } - if (ioremap_pmd_range(pud, addr, next, phys_addr, prot)) + if (ioremap_pmd_range(pud, addr, next, phys_addr, prot, mask)) return -ENOMEM; } while (pud++, phys_addr += (next - addr), addr = next, addr != end); return 0; @@ -187,21 +195,24 @@ static int ioremap_try_huge_p4d(p4d_t *p } static inline int ioremap_p4d_range(pgd_t *pgd, unsigned long addr, - unsigned long end, phys_addr_t phys_addr, pgprot_t prot) + unsigned long end, phys_addr_t phys_addr, pgprot_t prot, + pgtbl_mod_mask *mask) { p4d_t *p4d; unsigned long next; - p4d = p4d_alloc(&init_mm, pgd, addr); + p4d = p4d_alloc_track(&init_mm, pgd, addr, mask); if (!p4d) return -ENOMEM; do { next = p4d_addr_end(addr, end); - if (ioremap_try_huge_p4d(p4d, addr, next, phys_addr, prot)) + if (ioremap_try_huge_p4d(p4d, addr, next, phys_addr, prot)) { + *mask |= PGTBL_P4D_MODIFIED; continue; + } - if (ioremap_pud_range(p4d, addr, next, phys_addr, prot)) + if (ioremap_pud_range(p4d, addr, next, phys_addr, prot, mask)) return -ENOMEM; } while (p4d++, phys_addr += (next - addr), addr = next, addr != end); return 0; @@ -214,6 +225,7 @@ int ioremap_page_range(unsigned long add unsigned long start; unsigned long next; int err; + pgtbl_mod_mask mask = 0; might_sleep(); BUG_ON(addr >= end); @@ -222,13 +234,17 @@ int ioremap_page_range(unsigned long add pgd = pgd_offset_k(addr); do { next = pgd_addr_end(addr, end); - err = ioremap_p4d_range(pgd, addr, next, phys_addr, prot); + err = ioremap_p4d_range(pgd, addr, next, phys_addr, prot, + &mask); if (err) break; } while (pgd++, phys_addr += (next - addr), addr = next, addr != end); flush_cache_vmap(start, end); + if (mask & ARCH_PAGE_TABLE_SYNC_MASK) + arch_sync_kernel_mappings(start, end); + return err; } _
