diff options
Diffstat (limited to 'arch/powerpc/include/asm/book3s')
| -rw-r--r-- | arch/powerpc/include/asm/book3s/32/kup.h | 69 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/book3s/32/pgalloc.h | 8 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/book3s/32/pgtable.h | 23 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/book3s/64/kup-radix.h | 40 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/book3s/64/mmu-hash.h | 5 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/book3s/64/mmu.h | 4 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/book3s/64/pgalloc.h | 17 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/book3s/64/pgtable-4k.h | 3 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/book3s/64/pgtable-64k.h | 3 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/book3s/64/pgtable.h | 11 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/book3s/64/radix.h | 11 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/book3s/64/tlbflush-radix.h | 10 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/book3s/64/tlbflush.h | 19 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/book3s/pgtable.h | 11 |
14 files changed, 145 insertions, 89 deletions
diff --git a/arch/powerpc/include/asm/book3s/32/kup.h b/arch/powerpc/include/asm/book3s/32/kup.h index 677e9babef80..3c0ba22dc360 100644 --- a/arch/powerpc/include/asm/book3s/32/kup.h +++ b/arch/powerpc/include/asm/book3s/32/kup.h @@ -91,6 +91,7 @@ static inline void kuap_update_sr(u32 sr, u32 addr, u32 end) { + addr &= 0xf0000000; /* align addr to start of segment */ barrier(); /* make sure thread.kuap is updated before playing with SRs */ while (addr < end) { mtsrin(sr, addr); @@ -101,41 +102,91 @@ static inline void kuap_update_sr(u32 sr, u32 addr, u32 end) isync(); /* Context sync required after mtsrin() */ } -static inline void allow_user_access(void __user *to, const void __user *from, u32 size) +static __always_inline void allow_user_access(void __user *to, const void __user *from, + u32 size, unsigned long dir) { u32 addr, end; - if (__builtin_constant_p(to) && to == NULL) + BUILD_BUG_ON(!__builtin_constant_p(dir)); + BUILD_BUG_ON(dir == KUAP_CURRENT); + + if (!(dir & KUAP_WRITE)) return; addr = (__force u32)to; - if (!addr || addr >= TASK_SIZE || !size) + if (unlikely(addr >= TASK_SIZE || !size)) return; end = min(addr + size, TASK_SIZE); + current->thread.kuap = (addr & 0xf0000000) | ((((end - 1) >> 28) + 1) & 0xf); kuap_update_sr(mfsrin(addr) & ~SR_KS, addr, end); /* Clear Ks */ } -static inline void prevent_user_access(void __user *to, const void __user *from, u32 size) +static __always_inline void prevent_user_access(void __user *to, const void __user *from, + u32 size, unsigned long dir) { - u32 addr = (__force u32)to; - u32 end = min(addr + size, TASK_SIZE); + u32 addr, end; + + BUILD_BUG_ON(!__builtin_constant_p(dir)); + + if (dir == KUAP_CURRENT) { + u32 kuap = current->thread.kuap; - if (!addr || addr >= TASK_SIZE || !size) + if (unlikely(!kuap)) + return; + + addr = kuap & 0xf0000000; + end = kuap << 28; + } else if (dir & KUAP_WRITE) { + addr = (__force u32)to; + end = min(addr + size, TASK_SIZE); + + if (unlikely(addr >= TASK_SIZE || !size)) + return; + } else { return; + } current->thread.kuap = 0; kuap_update_sr(mfsrin(addr) | SR_KS, addr, end); /* set Ks */ } -static inline bool bad_kuap_fault(struct pt_regs *regs, bool is_write) +static inline unsigned long prevent_user_access_return(void) +{ + unsigned long flags = current->thread.kuap; + unsigned long addr = flags & 0xf0000000; + unsigned long end = flags << 28; + void __user *to = (__force void __user *)addr; + + if (flags) + prevent_user_access(to, to, end - addr, KUAP_READ_WRITE); + + return flags; +} + +static inline void restore_user_access(unsigned long flags) { + unsigned long addr = flags & 0xf0000000; + unsigned long end = flags << 28; + void __user *to = (__force void __user *)addr; + + if (flags) + allow_user_access(to, to, end - addr, KUAP_READ_WRITE); +} + +static inline bool +bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write) +{ + unsigned long begin = regs->kuap & 0xf0000000; + unsigned long end = regs->kuap << 28; + if (!is_write) return false; - return WARN(!regs->kuap, "Bug: write fault blocked by segment registers !"); + return WARN(address < begin || address >= end, + "Bug: write fault blocked by segment registers !"); } #endif /* CONFIG_PPC_KUAP */ diff --git a/arch/powerpc/include/asm/book3s/32/pgalloc.h b/arch/powerpc/include/asm/book3s/32/pgalloc.h index 998317702630..dc5c039eb28e 100644 --- a/arch/powerpc/include/asm/book3s/32/pgalloc.h +++ b/arch/powerpc/include/asm/book3s/32/pgalloc.h @@ -49,7 +49,6 @@ static inline void pgtable_free(void *table, unsigned index_size) #define get_hugepd_cache_index(x) (x) -#ifdef CONFIG_SMP static inline void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int shift) { @@ -66,13 +65,6 @@ static inline void __tlb_remove_table(void *_table) pgtable_free(table, shift); } -#else -static inline void pgtable_free_tlb(struct mmu_gather *tlb, - void *table, int shift) -{ - pgtable_free(table, shift); -} -#endif static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t table, unsigned long address) diff --git a/arch/powerpc/include/asm/book3s/32/pgtable.h b/arch/powerpc/include/asm/book3s/32/pgtable.h index 838de59f6754..5b39c11e884a 100644 --- a/arch/powerpc/include/asm/book3s/32/pgtable.h +++ b/arch/powerpc/include/asm/book3s/32/pgtable.h @@ -148,23 +148,21 @@ int map_kernel_page(unsigned long va, phys_addr_t pa, pgprot_t prot); */ #include <asm/fixmap.h> -#ifdef CONFIG_HIGHMEM -#define KVIRT_TOP PKMAP_BASE -#else -#define KVIRT_TOP FIXADDR_START -#endif - /* * ioremap_bot starts at that address. Early ioremaps move down from there, * until mem_init() at which point this becomes the top of the vmalloc * and ioremap space */ -#ifdef CONFIG_NOT_COHERENT_CACHE -#define IOREMAP_TOP ((KVIRT_TOP - CONFIG_CONSISTENT_SIZE) & PAGE_MASK) +#ifdef CONFIG_HIGHMEM +#define IOREMAP_TOP PKMAP_BASE #else -#define IOREMAP_TOP KVIRT_TOP +#define IOREMAP_TOP FIXADDR_START #endif +/* PPC32 shares vmalloc area with ioremap */ +#define IOREMAP_START VMALLOC_START +#define IOREMAP_END VMALLOC_END + /* * Just any arbitrary offset to the start of the vmalloc VM area: the * current 16MB value just means that there will be a 64MB "hole" after the @@ -195,14 +193,17 @@ int map_kernel_page(unsigned long va, phys_addr_t pa, pgprot_t prot); #else #define VMALLOC_START ((((long)high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))) #endif + +#ifdef CONFIG_KASAN_VMALLOC +#define VMALLOC_END _ALIGN_DOWN(ioremap_bot, PAGE_SIZE << KASAN_SHADOW_SCALE_SHIFT) +#else #define VMALLOC_END ioremap_bot +#endif #ifndef __ASSEMBLY__ #include <linux/sched.h> #include <linux/threads.h> -extern unsigned long ioremap_bot; - /* Bits to mask out from a PGD to get to the PUD page */ #define PGD_MASKED_BITS 0 diff --git a/arch/powerpc/include/asm/book3s/64/kup-radix.h b/arch/powerpc/include/asm/book3s/64/kup-radix.h index f254de956d6a..90dd3a3fc8c7 100644 --- a/arch/powerpc/include/asm/book3s/64/kup-radix.h +++ b/arch/powerpc/include/asm/book3s/64/kup-radix.h @@ -63,6 +63,14 @@ * because that would require an expensive read/modify write of the AMR. */ +static inline unsigned long get_kuap(void) +{ + if (!early_mmu_has_feature(MMU_FTR_RADIX_KUAP)) + return 0; + + return mfspr(SPRN_AMR); +} + static inline void set_kuap(unsigned long value) { if (!early_mmu_has_feature(MMU_FTR_RADIX_KUAP)) @@ -77,25 +85,43 @@ static inline void set_kuap(unsigned long value) isync(); } -static inline void allow_user_access(void __user *to, const void __user *from, - unsigned long size) +static __always_inline void allow_user_access(void __user *to, const void __user *from, + unsigned long size, unsigned long dir) { // This is written so we can resolve to a single case at build time - if (__builtin_constant_p(to) && to == NULL) + BUILD_BUG_ON(!__builtin_constant_p(dir)); + if (dir == KUAP_READ) set_kuap(AMR_KUAP_BLOCK_WRITE); - else if (__builtin_constant_p(from) && from == NULL) + else if (dir == KUAP_WRITE) set_kuap(AMR_KUAP_BLOCK_READ); - else + else if (dir == KUAP_READ_WRITE) set_kuap(0); + else + BUILD_BUG(); } static inline void prevent_user_access(void __user *to, const void __user *from, - unsigned long size) + unsigned long size, unsigned long dir) +{ + set_kuap(AMR_KUAP_BLOCKED); +} + +static inline unsigned long prevent_user_access_return(void) { + unsigned long flags = get_kuap(); + set_kuap(AMR_KUAP_BLOCKED); + + return flags; +} + +static inline void restore_user_access(unsigned long flags) +{ + set_kuap(flags); } -static inline bool bad_kuap_fault(struct pt_regs *regs, bool is_write) +static inline bool +bad_kuap_fault(struct pt_regs *regs, unsigned long address, bool is_write) { return WARN(mmu_has_feature(MMU_FTR_RADIX_KUAP) && (regs->kuap & (is_write ? AMR_KUAP_BLOCK_WRITE : AMR_KUAP_BLOCK_READ)), diff --git a/arch/powerpc/include/asm/book3s/64/mmu-hash.h b/arch/powerpc/include/asm/book3s/64/mmu-hash.h index 15b75005bc34..3fa1b962dc27 100644 --- a/arch/powerpc/include/asm/book3s/64/mmu-hash.h +++ b/arch/powerpc/include/asm/book3s/64/mmu-hash.h @@ -600,8 +600,11 @@ extern void slb_set_size(u16 size); * */ #define MAX_USER_CONTEXT ((ASM_CONST(1) << CONTEXT_BITS) - 2) + +// The + 2 accounts for INVALID_REGION and 1 more to avoid overlap with kernel #define MIN_USER_CONTEXT (MAX_KERNEL_CTX_CNT + MAX_VMALLOC_CTX_CNT + \ - MAX_IO_CTX_CNT + MAX_VMEMMAP_CTX_CNT) + MAX_IO_CTX_CNT + MAX_VMEMMAP_CTX_CNT + 2) + /* * For platforms that support on 65bit VA we limit the context bits */ diff --git a/arch/powerpc/include/asm/book3s/64/mmu.h b/arch/powerpc/include/asm/book3s/64/mmu.h index 23b83d3593e2..bb3deb76c951 100644 --- a/arch/powerpc/include/asm/book3s/64/mmu.h +++ b/arch/powerpc/include/asm/book3s/64/mmu.h @@ -206,7 +206,6 @@ extern int mmu_io_psize; void mmu_early_init_devtree(void); void hash__early_init_devtree(void); void radix__early_init_devtree(void); -extern void radix_init_native(void); extern void hash__early_init_mmu(void); extern void radix__early_init_mmu(void); static inline void early_init_mmu(void) @@ -238,9 +237,6 @@ static inline void setup_initial_memory_limit(phys_addr_t first_memblock_base, first_memblock_size); } -extern int (*register_process_table)(unsigned long base, unsigned long page_size, - unsigned long tbl_size); - #ifdef CONFIG_PPC_PSERIES extern void radix_init_pseries(void); #else diff --git a/arch/powerpc/include/asm/book3s/64/pgalloc.h b/arch/powerpc/include/asm/book3s/64/pgalloc.h index d5a44912902f..a41e91bd0580 100644 --- a/arch/powerpc/include/asm/book3s/64/pgalloc.h +++ b/arch/powerpc/include/asm/book3s/64/pgalloc.h @@ -19,9 +19,7 @@ extern struct vmemmap_backing *vmemmap_list; extern pmd_t *pmd_fragment_alloc(struct mm_struct *, unsigned long); extern void pmd_fragment_free(unsigned long *); extern void pgtable_free_tlb(struct mmu_gather *tlb, void *table, int shift); -#ifdef CONFIG_SMP extern void __tlb_remove_table(void *_table); -#endif void pte_frag_destroy(void *pte_frag); static inline pgd_t *radix__pgd_alloc(struct mm_struct *mm) @@ -122,11 +120,6 @@ static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd) static inline void __pud_free_tlb(struct mmu_gather *tlb, pud_t *pud, unsigned long address) { - /* - * By now all the pud entries should be none entries. So go - * ahead and flush the page walk cache - */ - flush_tlb_pgtable(tlb, address); pgtable_free_tlb(tlb, pud, PUD_INDEX); } @@ -143,11 +136,6 @@ static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd) static inline void __pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd, unsigned long address) { - /* - * By now all the pud entries should be none entries. So go - * ahead and flush the page walk cache - */ - flush_tlb_pgtable(tlb, address); return pgtable_free_tlb(tlb, pmd, PMD_INDEX); } @@ -166,11 +154,6 @@ static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd, static inline void __pte_free_tlb(struct mmu_gather *tlb, pgtable_t table, unsigned long address) { - /* - * By now all the pud entries should be none entries. So go - * ahead and flush the page walk cache - */ - flush_tlb_pgtable(tlb, address); pgtable_free_tlb(tlb, table, PTE_INDEX); } diff --git a/arch/powerpc/include/asm/book3s/64/pgtable-4k.h b/arch/powerpc/include/asm/book3s/64/pgtable-4k.h index a069dfcac9a9..4e697bc2f4cd 100644 --- a/arch/powerpc/include/asm/book3s/64/pgtable-4k.h +++ b/arch/powerpc/include/asm/book3s/64/pgtable-4k.h @@ -70,9 +70,6 @@ static inline int get_hugepd_cache_index(int index) /* should not reach */ } -#else /* !CONFIG_HUGETLB_PAGE */ -static inline int pmd_huge(pmd_t pmd) { return 0; } -static inline int pud_huge(pud_t pud) { return 0; } #endif /* CONFIG_HUGETLB_PAGE */ #endif /* __ASSEMBLY__ */ diff --git a/arch/powerpc/include/asm/book3s/64/pgtable-64k.h b/arch/powerpc/include/asm/book3s/64/pgtable-64k.h index e3d4dd4ae2fa..34d1018896b3 100644 --- a/arch/powerpc/include/asm/book3s/64/pgtable-64k.h +++ b/arch/powerpc/include/asm/book3s/64/pgtable-64k.h @@ -59,9 +59,6 @@ static inline int get_hugepd_cache_index(int index) BUG(); } -#else /* !CONFIG_HUGETLB_PAGE */ -static inline int pmd_huge(pmd_t pmd) { return 0; } -static inline int pud_huge(pud_t pud) { return 0; } #endif /* CONFIG_HUGETLB_PAGE */ static inline int remap_4k_pfn(struct vm_area_struct *vma, unsigned long addr, diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h index 8308f32e9782..201a69e6a355 100644 --- a/arch/powerpc/include/asm/book3s/64/pgtable.h +++ b/arch/powerpc/include/asm/book3s/64/pgtable.h @@ -289,7 +289,6 @@ extern unsigned long __kernel_io_end; #define KERN_IO_END __kernel_io_end extern struct page *vmemmap; -extern unsigned long ioremap_bot; extern unsigned long pci_io_base; #endif /* __ASSEMBLY__ */ @@ -317,6 +316,7 @@ extern unsigned long pci_io_base; #define PHB_IO_BASE (ISA_IO_END) #define PHB_IO_END (KERN_IO_START + FULL_IO_SIZE) #define IOREMAP_BASE (PHB_IO_END) +#define IOREMAP_START (ioremap_bot) #define IOREMAP_END (KERN_IO_END) /* Advertise special mapping type for AGP */ @@ -608,8 +608,10 @@ static inline bool pte_access_permitted(pte_t pte, bool write) */ static inline pte_t pfn_pte(unsigned long pfn, pgprot_t pgprot) { - return __pte((((pte_basic_t)(pfn) << PAGE_SHIFT) & PTE_RPN_MASK) | - pgprot_val(pgprot)); + VM_BUG_ON(pfn >> (64 - PAGE_SHIFT)); + VM_BUG_ON((pfn << PAGE_SHIFT) & ~PTE_RPN_MASK); + + return __pte(((pte_basic_t)pfn << PAGE_SHIFT) | pgprot_val(pgprot)); } static inline unsigned long pte_pfn(pte_t pte) @@ -1353,18 +1355,21 @@ static inline bool is_pte_rw_upgrade(unsigned long old_val, unsigned long new_va * Like pmd_huge() and pmd_large(), but works regardless of config options */ #define pmd_is_leaf pmd_is_leaf +#define pmd_leaf pmd_is_leaf static inline bool pmd_is_leaf(pmd_t pmd) { return !!(pmd_raw(pmd) & cpu_to_be64(_PAGE_PTE)); } #define pud_is_leaf pud_is_leaf +#define pud_leaf pud_is_leaf static inline bool pud_is_leaf(pud_t pud) { return !!(pud_raw(pud) & cpu_to_be64(_PAGE_PTE)); } #define pgd_is_leaf pgd_is_leaf +#define pgd_leaf pgd_is_leaf static inline bool pgd_is_leaf(pgd_t pgd) { return !!(pgd_raw(pgd) & cpu_to_be64(_PAGE_PTE)); diff --git a/arch/powerpc/include/asm/book3s/64/radix.h b/arch/powerpc/include/asm/book3s/64/radix.h index e04a839cb5b9..d97db3ad9aae 100644 --- a/arch/powerpc/include/asm/book3s/64/radix.h +++ b/arch/powerpc/include/asm/book3s/64/radix.h @@ -254,7 +254,13 @@ extern void radix__pgtable_trans_huge_deposit(struct mm_struct *mm, pmd_t *pmdp, extern pgtable_t radix__pgtable_trans_huge_withdraw(struct mm_struct *mm, pmd_t *pmdp); extern pmd_t radix__pmdp_huge_get_and_clear(struct mm_struct *mm, unsigned long addr, pmd_t *pmdp); -extern int radix__has_transparent_hugepage(void); +static inline int radix__has_transparent_hugepage(void) +{ + /* For radix 2M at PMD level means thp */ + if (mmu_psize_defs[MMU_PAGE_2M].shift == PMD_SHIFT) + return 1; + return 0; +} #endif extern int __meminit radix__vmemmap_create_mapping(unsigned long start, @@ -266,9 +272,6 @@ extern void radix__vmemmap_remove_mapping(unsigned long start, extern int radix__map_kernel_page(unsigned long ea, unsigned long pa, pgprot_t flags, unsigned int psz); -extern int radix__ioremap_range(unsigned long ea, phys_addr_t pa, - unsigned long size, pgprot_t prot, int nid); - static inline unsigned long radix__get_tree_size(void) { unsigned long rts_field; diff --git a/arch/powerpc/include/asm/book3s/64/tlbflush-radix.h b/arch/powerpc/include/asm/book3s/64/tlbflush-radix.h index 05147cecb8df..ca8db193ae38 100644 --- a/arch/powerpc/include/asm/book3s/64/tlbflush-radix.h +++ b/arch/powerpc/include/asm/book3s/64/tlbflush-radix.h @@ -17,8 +17,8 @@ extern void radix__flush_tlb_lpid_page(unsigned int lpid, unsigned long addr, unsigned long page_size); extern void radix__flush_pwc_lpid(unsigned int lpid); -extern void radix__flush_tlb_lpid(unsigned int lpid); -extern void radix__local_flush_tlb_lpid_guest(unsigned int lpid); +extern void radix__flush_all_lpid(unsigned int lpid); +extern void radix__flush_all_lpid_guest(unsigned int lpid); #else static inline void radix__tlbiel_all(unsigned int action) { WARN_ON(1); }; static inline void radix__flush_tlb_lpid_page(unsigned int lpid, @@ -31,11 +31,11 @@ static inline void radix__flush_pwc_lpid(unsigned int lpid) { WARN_ON(1); } -static inline void radix__flush_tlb_lpid(unsigned int lpid) +static inline void radix__flush_all_lpid(unsigned int lpid) { WARN_ON(1); } -static inline void radix__local_flush_tlb_lpid_guest(unsigned int lpid) +static inline void radix__flush_all_lpid_guest(unsigned int lpid) { WARN_ON(1); } @@ -73,6 +73,4 @@ extern void radix__flush_tlb_pwc(struct mmu_gather *tlb, unsigned long addr); extern void radix__flush_tlb_collapsed_pmd(struct mm_struct *mm, unsigned long addr); extern void radix__flush_tlb_all(void); -extern void radix__local_flush_tlb_lpid(unsigned int lpid); - #endif diff --git a/arch/powerpc/include/asm/book3s/64/tlbflush.h b/arch/powerpc/include/asm/book3s/64/tlbflush.h index ebf572ea621e..dcb5c3839d2f 100644 --- a/arch/powerpc/include/asm/book3s/64/tlbflush.h +++ b/arch/powerpc/include/asm/book3s/64/tlbflush.h @@ -147,19 +147,12 @@ static inline void flush_tlb_fix_spurious_fault(struct vm_area_struct *vma, flush_tlb_page(vma, address); } -/* - * flush the page walk cache for the address - */ -static inline void flush_tlb_pgtable(struct mmu_gather *tlb, unsigned long address) -{ - /* - * Flush the page table walk cache on freeing a page table. We already - * have marked the upper/higher level page table entry none by now. - * So it is safe to flush PWC here. - */ - if (!radix_enabled()) - return; +extern bool tlbie_capable; +extern bool tlbie_enabled; - radix__flush_tlb_pwc(tlb, address); +static inline bool cputlb_use_tlbie(void) +{ + return tlbie_enabled; } + #endif /* _ASM_POWERPC_BOOK3S_64_TLBFLUSH_H */ diff --git a/arch/powerpc/include/asm/book3s/pgtable.h b/arch/powerpc/include/asm/book3s/pgtable.h index 6436b65ac7bc..0e1263455d73 100644 --- a/arch/powerpc/include/asm/book3s/pgtable.h +++ b/arch/powerpc/include/asm/book3s/pgtable.h @@ -26,5 +26,16 @@ extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn, unsigned long size, pgprot_t vma_prot); #define __HAVE_PHYS_MEM_ACCESS_PROT +/* + * This gets called at the end of handling a page fault, when + * the kernel has put a new PTE into the page table for the process. + * We use it to ensure coherency between the i-cache and d-cache + * for the page which has just been mapped in. + * On machines which use an MMU hash table, we use this to put a + * corresponding HPTE into the hash table ahead of time, instead of + * waiting for the inevitable extra hash-table miss exception. + */ +void update_mmu_cache(struct vm_area_struct *vma, unsigned long address, pte_t *ptep); + #endif /* __ASSEMBLY__ */ #endif |
