diff options
Diffstat (limited to 'arch/tile/mm/pgtable.c')
| -rw-r--r-- | arch/tile/mm/pgtable.c | 38 |
1 files changed, 24 insertions, 14 deletions
diff --git a/arch/tile/mm/pgtable.c b/arch/tile/mm/pgtable.c index 87303693a07..2410aa899b3 100644 --- a/arch/tile/mm/pgtable.c +++ b/arch/tile/mm/pgtable.c @@ -177,14 +177,10 @@ void shatter_huge_page(unsigned long addr) if (!pmd_huge_page(*pmd)) return; - /* - * Grab the pgd_lock, since we may need it to walk the pgd_list, - * and since we need some kind of lock here to avoid races. - */ - spin_lock_irqsave(&pgd_lock, flags); + spin_lock_irqsave(&init_mm.page_table_lock, flags); if (!pmd_huge_page(*pmd)) { /* Lost the race to convert the huge page. */ - spin_unlock_irqrestore(&pgd_lock, flags); + spin_unlock_irqrestore(&init_mm.page_table_lock, flags); return; } @@ -194,6 +190,7 @@ void shatter_huge_page(unsigned long addr) #ifdef __PAGETABLE_PMD_FOLDED /* Walk every pgd on the system and update the pmd there. */ + spin_lock(&pgd_lock); list_for_each(pos, &pgd_list) { pmd_t *copy_pmd; pgd = list_to_pgd(pos) + pgd_index(addr); @@ -201,6 +198,7 @@ void shatter_huge_page(unsigned long addr) copy_pmd = pmd_offset(pud, addr); __set_pmd(copy_pmd, *pmd); } + spin_unlock(&pgd_lock); #endif /* Tell every cpu to notice the change. */ @@ -208,7 +206,7 @@ void shatter_huge_page(unsigned long addr) cpu_possible_mask, NULL, 0); /* Hold the lock until the TLB flush is finished to avoid races. */ - spin_unlock_irqrestore(&pgd_lock, flags); + spin_unlock_irqrestore(&init_mm.page_table_lock, flags); } /* @@ -217,9 +215,13 @@ void shatter_huge_page(unsigned long addr) * against pageattr.c; it is the unique case in which a valid change * of kernel pagetables can't be lazily synchronized by vmalloc faults. * vmalloc faults work because attached pagetables are never freed. - * The locking scheme was chosen on the basis of manfred's - * recommendations and having no core impact whatsoever. - * -- wli + * + * The lock is always taken with interrupts disabled, unlike on x86 + * and other platforms, because we need to take the lock in + * shatter_huge_page(), which may be called from an interrupt context. + * We are not at risk from the tlbflush IPI deadlock that was seen on + * x86, since we use the flush_remote() API to have the hypervisor do + * the TLB flushes regardless of irq disabling. */ DEFINE_SPINLOCK(pgd_lock); LIST_HEAD(pgd_list); @@ -469,10 +471,18 @@ void __set_pte(pte_t *ptep, pte_t pte) void set_pte(pte_t *ptep, pte_t pte) { - struct page *page = pfn_to_page(pte_pfn(pte)); - - /* Update the home of a PTE if necessary */ - pte = pte_set_home(pte, page_home(page)); + if (pte_present(pte) && + (!CHIP_HAS_MMIO() || hv_pte_get_mode(pte) != HV_PTE_MODE_MMIO)) { + /* The PTE actually references physical memory. */ + unsigned long pfn = pte_pfn(pte); + if (pfn_valid(pfn)) { + /* Update the home of the PTE from the struct page. */ + pte = pte_set_home(pte, page_home(pfn_to_page(pfn))); + } else if (hv_pte_get_mode(pte) == 0) { + /* remap_pfn_range(), etc, must supply PTE mode. */ + panic("set_pte(): out-of-range PFN and mode 0\n"); + } + } __set_pte(ptep, pte); } |