diff options
Diffstat (limited to 'arch/tile/mm')
| -rw-r--r-- | arch/tile/mm/fault.c | 22 | ||||
| -rw-r--r-- | arch/tile/mm/homecache.c | 1 | ||||
| -rw-r--r-- | arch/tile/mm/init.c | 26 | ||||
| -rw-r--r-- | arch/tile/mm/pgtable.c | 38 |
4 files changed, 56 insertions, 31 deletions
diff --git a/arch/tile/mm/fault.c b/arch/tile/mm/fault.c index cba30e9547b4..22e58f51ed23 100644 --- a/arch/tile/mm/fault.c +++ b/arch/tile/mm/fault.c @@ -130,7 +130,7 @@ static inline pmd_t *vmalloc_sync_one(pgd_t *pgd, unsigned long address) } /* - * Handle a fault on the vmalloc or module mapping area + * Handle a fault on the vmalloc area. */ static inline int vmalloc_fault(pgd_t *pgd, unsigned long address) { @@ -203,9 +203,14 @@ static pgd_t *get_current_pgd(void) * interrupt or a critical region, and must do as little as possible. * Similarly, we can't use atomic ops here, since we may be handling a * fault caused by an atomic op access. + * + * If we find a migrating PTE while we're in an NMI context, and we're + * at a PC that has a registered exception handler, we don't wait, + * since this thread may (e.g.) have been interrupted while migrating + * its own stack, which would then cause us to self-deadlock. */ static int handle_migrating_pte(pgd_t *pgd, int fault_num, - unsigned long address, + unsigned long address, unsigned long pc, int is_kernel_mode, int write) { pud_t *pud; @@ -227,6 +232,8 @@ static int handle_migrating_pte(pgd_t *pgd, int fault_num, pte_offset_kernel(pmd, address); pteval = *pte; if (pte_migrating(pteval)) { + if (in_nmi() && search_exception_tables(pc)) + return 0; wait_for_migration(pte); return 1; } @@ -300,7 +307,7 @@ static int handle_page_fault(struct pt_regs *regs, * rather than trying to patch up the existing PTE. */ pgd = get_current_pgd(); - if (handle_migrating_pte(pgd, fault_num, address, + if (handle_migrating_pte(pgd, fault_num, address, regs->pc, is_kernel_mode, write)) return 1; @@ -335,9 +342,12 @@ static int handle_page_fault(struct pt_regs *regs, /* * If we're trying to touch user-space addresses, we must * be either at PL0, or else with interrupts enabled in the - * kernel, so either way we can re-enable interrupts here. + * kernel, so either way we can re-enable interrupts here + * unless we are doing atomic access to user space with + * interrupts disabled. */ - local_irq_enable(); + if (!(regs->flags & PT_FLAGS_DISABLE_IRQ)) + local_irq_enable(); mm = tsk->mm; @@ -665,7 +675,7 @@ struct intvec_state do_page_fault_ics(struct pt_regs *regs, int fault_num, */ if (fault_num == INT_DTLB_ACCESS) write = 1; - if (handle_migrating_pte(pgd, fault_num, address, 1, write)) + if (handle_migrating_pte(pgd, fault_num, address, pc, 1, write)) return state; /* Return zero so that we continue on with normal fault handling. */ diff --git a/arch/tile/mm/homecache.c b/arch/tile/mm/homecache.c index 1cc6ae477c98..499f73770b05 100644 --- a/arch/tile/mm/homecache.c +++ b/arch/tile/mm/homecache.c @@ -394,6 +394,7 @@ int page_home(struct page *page) return pte_to_home(*virt_to_pte(NULL, kva)); } } +EXPORT_SYMBOL(page_home); void homecache_change_page_home(struct page *page, int order, int home) { diff --git a/arch/tile/mm/init.c b/arch/tile/mm/init.c index 830c4908ea76..6a9d20ddc34f 100644 --- a/arch/tile/mm/init.c +++ b/arch/tile/mm/init.c @@ -254,11 +254,6 @@ static pgprot_t __init init_pgprot(ulong address) return construct_pgprot(PAGE_KERNEL_RO, PAGE_HOME_IMMUTABLE); } - /* As a performance optimization, keep the boot init stack here. */ - if (address >= (ulong)&init_thread_union && - address < (ulong)&init_thread_union + THREAD_SIZE) - return construct_pgprot(PAGE_KERNEL, smp_processor_id()); - #ifndef __tilegx__ #if !ATOMIC_LOCKS_FOUND_VIA_TABLE() /* Force the atomic_locks[] array page to be hash-for-home. */ @@ -557,6 +552,7 @@ static void __init kernel_physical_mapping_init(pgd_t *pgd_base) address = MEM_SV_INTRPT; pmd = get_pmd(pgtables, address); + pfn = 0; /* code starts at PA 0 */ if (ktext_small) { /* Allocate an L2 PTE for the kernel text */ int cpu = 0; @@ -579,10 +575,15 @@ static void __init kernel_physical_mapping_init(pgd_t *pgd_base) } BUG_ON(address != (unsigned long)_stext); - pfn = 0; /* code starts at PA 0 */ - pte = alloc_pte(); - for (pte_ofs = 0; address < (unsigned long)_einittext; - pfn++, pte_ofs++, address += PAGE_SIZE) { + pte = NULL; + for (; address < (unsigned long)_einittext; + pfn++, address += PAGE_SIZE) { + pte_ofs = pte_index(address); + if (pte_ofs == 0) { + if (pte) + assign_pte(pmd++, pte); + pte = alloc_pte(); + } if (!ktext_local) { prot = set_remote_cache_cpu(prot, cpu); cpu = cpumask_next(cpu, &ktext_mask); @@ -591,7 +592,8 @@ static void __init kernel_physical_mapping_init(pgd_t *pgd_base) } pte[pte_ofs] = pfn_pte(pfn, prot); } - assign_pte(pmd, pte); + if (pte) + assign_pte(pmd, pte); } else { pte_t pteval = pfn_pte(0, PAGE_KERNEL_EXEC); pteval = pte_mkhuge(pteval); @@ -614,7 +616,9 @@ static void __init kernel_physical_mapping_init(pgd_t *pgd_base) else pteval = hv_pte_set_mode(pteval, HV_PTE_MODE_CACHE_NO_L3); - *(pte_t *)pmd = pteval; + for (; address < (unsigned long)_einittext; + pfn += PFN_DOWN(HPAGE_SIZE), address += HPAGE_SIZE) + *(pte_t *)(pmd++) = pfn_pte(pfn, pteval); } /* Set swapper_pgprot here so it is flushed to memory right away. */ diff --git a/arch/tile/mm/pgtable.c b/arch/tile/mm/pgtable.c index 87303693a072..2410aa899b3e 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); } |