/* SPDX-License-Identifier: GPL-2.0 */ #ifndef _ASM_POWERPC_BOOK3S_32_PGTABLE_H #define _ASM_POWERPC_BOOK3S_32_PGTABLE_H #include <asm-generic/pgtable-nopmd.h> /* * The "classic" 32-bit implementation of the PowerPC MMU uses a hash * table containing PTEs, together with a set of 16 segment registers, * to define the virtual to physical address mapping. * * We use the hash table as an extended TLB, i.e. a cache of currently * active mappings. We maintain a two-level page table tree, much * like that used by the i386, for the sake of the Linux memory * management code. Low-level assembler code in hash_low_32.S * (procedure hash_page) is responsible for extracting ptes from the * tree and putting them into the hash table when necessary, and * updating the accessed and modified bits in the page table tree. */ #define _PAGE_PRESENT 0x001 /* software: pte contains a translation */ #define _PAGE_HASHPTE 0x002 /* hash_page has made an HPTE for this pte */ #define _PAGE_USER 0x004 /* usermode access allowed */ #define _PAGE_GUARDED 0x008 /* G: prohibit speculative access */ #define _PAGE_COHERENT 0x010 /* M: enforce memory coherence (SMP systems) */ #define _PAGE_NO_CACHE 0x020 /* I: cache inhibit */ #define _PAGE_WRITETHRU 0x040 /* W: cache write-through */ #define _PAGE_DIRTY 0x080 /* C: page changed */ #define _PAGE_ACCESSED 0x100 /* R: page referenced */ #define _PAGE_EXEC 0x200 /* software: exec allowed */ #define _PAGE_RW 0x400 /* software: user write access allowed */ #define _PAGE_SPECIAL 0x800 /* software: Special page */ #ifdef CONFIG_PTE_64BIT /* We never clear the high word of the pte */ #define _PTE_NONE_MASK (0xffffffff00000000ULL | _PAGE_HASHPTE) #else #define _PTE_NONE_MASK _PAGE_HASHPTE #endif #define _PMD_PRESENT 0 #define _PMD_PRESENT_MASK (PAGE_MASK) #define _PMD_BAD (~PAGE_MASK) /* We borrow the _PAGE_USER bit to store the exclusive marker in swap PTEs. */ #define _PAGE_SWP_EXCLUSIVE _PAGE_USER /* And here we include common definitions */ #define _PAGE_KERNEL_RO 0 #define _PAGE_KERNEL_ROX (_PAGE_EXEC) #define _PAGE_KERNEL_RW (_PAGE_DIRTY | _PAGE_RW) #define _PAGE_KERNEL_RWX (_PAGE_DIRTY | _PAGE_RW | _PAGE_EXEC) #define _PAGE_HPTEFLAGS _PAGE_HASHPTE #ifndef __ASSEMBLY__ static inline bool pte_user(pte_t pte) { return pte_val(pte) & _PAGE_USER; } #endif /* __ASSEMBLY__ */ /* * Location of the PFN in the PTE. Most 32-bit platforms use the same * as _PAGE_SHIFT here (ie, naturally aligned). * Platform who don't just pre-define the value so we don't override it here. */ #define PTE_RPN_SHIFT (PAGE_SHIFT) /* * The mask covered by the RPN must be a ULL on 32-bit platforms with * 64-bit PTEs. */ #ifdef CONFIG_PTE_64BIT #define PTE_RPN_MASK (~((1ULL << PTE_RPN_SHIFT) - 1)) #define MAX_POSSIBLE_PHYSMEM_BITS 36 #else #define PTE_RPN_MASK (~((1UL << PTE_RPN_SHIFT) - 1)) #define MAX_POSSIBLE_PHYSMEM_BITS 32 #endif /* * _PAGE_CHG_MASK masks of bits that are to be preserved across * pgprot changes. */ #define _PAGE_CHG_MASK (PTE_RPN_MASK | _PAGE_HASHPTE | _PAGE_DIRTY | \ _PAGE_ACCESSED | _PAGE_SPECIAL) /* * We define 2 sets of base prot bits, one for basic pages (ie, * cacheable kernel and user pages) and one for non cacheable * pages. We always set _PAGE_COHERENT when SMP is enabled or * the processor might need it for DMA coherency. */ #define _PAGE_BASE_NC (_PAGE_PRESENT | _PAGE_ACCESSED) #define _PAGE_BASE (_PAGE_BASE_NC | _PAGE_COHERENT) /* * Permission masks used to generate the __P and __S table. * * Note:__pgprot is defined in arch/powerpc/include/asm/page.h * * Write permissions imply read permissions for now. */ #define PAGE_NONE __pgprot(_PAGE_BASE) #define PAGE_SHARED __pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW) #define PAGE_SHARED_X __pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_RW | _PAGE_EXEC) #define PAGE_COPY __pgprot(_PAGE_BASE | _PAGE_USER) #define PAGE_COPY_X __pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC) #define PAGE_READONLY __pgprot(_PAGE_BASE | _PAGE_USER) #define PAGE_READONLY_X __pgprot(_PAGE_BASE | _PAGE_USER | _PAGE_EXEC) /* Permission masks used for kernel mappings */ #define PAGE_KERNEL __pgprot(_PAGE_BASE | _PAGE_KERNEL_RW) #define PAGE_KERNEL_NC __pgprot(_PAGE_BASE_NC | _PAGE_KERNEL_RW | _PAGE_NO_CACHE) #define PAGE_KERNEL_NCG __pgprot(_PAGE_BASE_NC | _PAGE_KERNEL_RW | _PAGE_NO_CACHE | _PAGE_GUARDED) #define PAGE_KERNEL_X __pgprot(_PAGE_BASE | _PAGE_KERNEL_RWX) #define PAGE_KERNEL_RO __pgprot(_PAGE_BASE | _PAGE_KERNEL_RO) #define PAGE_KERNEL_ROX __pgprot(_PAGE_BASE | _PAGE_KERNEL_ROX) #define PTE_INDEX_SIZE PTE_SHIFT #define PMD_INDEX_SIZE 0 #define PUD_INDEX_SIZE 0 #define PGD_INDEX_SIZE (32 - PGDIR_SHIFT) #define PMD_CACHE_INDEX PMD_INDEX_SIZE #define PUD_CACHE_INDEX PUD_INDEX_SIZE #ifndef __ASSEMBLY__ #define PTE_TABLE_SIZE (sizeof(pte_t) << PTE_INDEX_SIZE) #define PMD_TABLE_SIZE 0 #define PUD_TABLE_SIZE 0 #define PGD_TABLE_SIZE (sizeof(pgd_t) << PGD_INDEX_SIZE) /* Bits to mask out from a PMD to get to the PTE page */ #define PMD_MASKED_BITS (PTE_TABLE_SIZE - 1) #endif /* __ASSEMBLY__ */ #define PTRS_PER_PTE (1 << PTE_INDEX_SIZE) #define PTRS_PER_PGD (1 << PGD_INDEX_SIZE) /* * The normal case is that PTEs are 32-bits and we have a 1-page * 1024-entry pgdir pointing to 1-page 1024-entry PTE pages. -- paulus * * For any >32-bit physical address platform, we can use the following * two level page table layout where the pgdir is 8KB and the MS 13 bits * are an index to the second level table. The combined pgdir/pmd first * level has 2048 entries and the second level has 512 64-bit PTE entries. * -Matt */ /* PGDIR_SHIFT determines what a top-level page table entry can map */ #define PGDIR_SHIFT (PAGE_SHIFT + PTE_INDEX_SIZE) #define PGDIR_SIZE (1UL << PGDIR_SHIFT) #define PGDIR_MASK (~(PGDIR_SIZE-1)) #define USER_PTRS_PER_PGD (TASK_SIZE / PGDIR_SIZE) #ifndef __ASSEMBLY__ int map_kernel_page(unsigned long va, phys_addr_t pa, pgprot_t prot); void unmap_kernel_page(unsigned long va); #endif /* !__ASSEMBLY__ */ /* * This is the bottom of the PKMAP area with HIGHMEM or an arbitrary * value (for now) on others, from where we can start layout kernel * virtual space that goes below PKMAP and FIXMAP */ #include <asm/fixmap.h> /* * 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_HIGHMEM #define IOREMAP_TOP PKMAP_BASE #else #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 * physical memory until the kernel virtual memory starts. That means that * any out-of-bounds memory accesses will hopefully be caught. * The vmalloc() routines leaves a hole of 4kB between each vmalloced * area for the same reason. ;) * * We no longer map larger than phys RAM with the BATs so we don't have * to worry about the VMALLOC_OFFSET causing problems. We do have to worry * about clashes between our early calls to ioremap() that start growing down * from ioremap_base being run into the VM area allocations (growing upwards * from VMALLOC_START). For this reason we have ioremap_bot to check when * we actually run into our mappings setup in the early boot with the VM * system. This really does become a problem for machines with good amounts * of RAM. -- Cort */ #define VMALLOC_OFFSET (0x1000000) /* 16M */ #define VMALLOC_START ((((long)high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))) #ifdef CONFIG_KASAN_VMALLOC #define VMALLOC_END ALIGN_DOWN(ioremap_bot, PAGE_SIZE << KASAN_SHADOW_SCALE_SHIFT) #else #define VMALLOC_END ioremap_bot #endif #define MODULES_END ALIGN_DOWN(PAGE_OFFSET, SZ_256M) #define MODULES_VADDR (MODULES_END - SZ_256M) #ifndef __ASSEMBLY__ #include <linux/sched.h> #include <linux/threads.h> /* Bits to mask out from a PGD to get to the PUD page */ #define PGD_MASKED_BITS 0 #define pte_ERROR(e) \ pr_err("%s:%d: bad pte %llx.\n", __FILE__, __LINE__, \ (unsigned long long)pte_val(e)) #define pgd_ERROR(e) \ pr_err("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e)) /* * Bits in a linux-style PTE. These match the bits in the * (hardware-defined) PowerPC PTE as closely as possible. */ #define pte_clear(mm, addr, ptep) \ do { pte_update(mm, addr, ptep, ~_PAGE_HASHPTE, 0, 0); } while (0) #define pmd_none(pmd) (!pmd_val(pmd)) #define pmd_bad(pmd) (pmd_val(pmd) & _PMD_BAD) #define pmd_present(pmd) (pmd_val(pmd) & _PMD_PRESENT_MASK) static inline void pmd_clear(pmd_t *pmdp) { *pmdp = __pmd(0); } /* * When flushing the tlb entry for a page, we also need to flush the hash * table entry. flush_hash_pages is assembler (for speed) in hashtable.S. */ extern int flush_hash_pages(unsigned context, unsigned long va, unsigned long pmdval, int count); /* Add an HPTE to the hash table */ extern void add_hash_page(unsigned context, unsigned long va, unsigned long pmdval); /* Flush an entry from the TLB/hash table */ static inline void flush_hash_entry(struct mm_struct *mm, pte_t *ptep, unsigned long addr) { if (mmu_has_feature(MMU_FTR_HPTE_TABLE)) { unsigned long ptephys = __pa(ptep) & PAGE_MASK; flush_hash_pages(mm->context.id, addr, ptephys, 1); } } /* * PTE updates. This function is called whenever an existing * valid PTE is updated. This does -not- include set_pte_at() * which nowadays only sets a new PTE. * * Depending on the type of MMU, we may need to use atomic updates * and the PTE may be either 32 or 64 bit wide. In the later case, * when using atomic updates, only the low part of the PTE is * accessed atomically. */ static inline pte_basic_t pte_update(struct mm_struct *mm, unsigned long addr, pte_t *p, unsigned long clr, unsigned long set, int huge) { pte_basic_t old; if (mmu_has_feature(MMU_FTR_HPTE_TABLE)) { unsigned long tmp; asm volatile( #ifndef CONFIG_PTE_64BIT "1: lwarx %0, 0, %3\n" " andc %1, %0, %4\n" #else "1: lwarx %L0, 0, %3\n" " lwz %0, -4(%3)\n" " andc %1, %L0, %4\n" #endif " or %1, %1, %5\n" " stwcx. %1, 0, %3\n" " bne- 1b" : "=&r" (old), "=&r" (tmp), "=m" (*p) #ifndef CONFIG_PTE_64BIT : "r" (p), #else : "b" ((unsigned long)(p) + 4), #endif "r" (clr), "r" (set), "m" (*p) : "cc" ); } else { old = pte_val(*p); *p = __pte((old & ~(pte_basic_t)clr) | set); } return old; } /* * 2.6 calls this without flushing the TLB entry; this is wrong * for our hash-based implementation, we fix that up here. */ #define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG static inline int __ptep_test_and_clear_young(struct mm_struct *mm, unsigned long addr, pte_t *ptep) { unsigned long old; old = pte_update(mm, addr, ptep, _PAGE_ACCESSED, 0, 0); if (old & _PAGE_HASHPTE) flush_hash_entry(mm, ptep, addr); return (old & _PAGE_ACCESSED) != 0; } #define ptep_test_and_clear_young(__vma, __addr, __ptep) \ __ptep_test_and_clear_young((__vma)->vm_mm, __addr, __ptep) #define __HAVE_ARCH_PTEP_GET_AND_CLEAR static inline pte_t ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep) { return __pte(pte_update(mm, addr, ptep, ~_PAGE_HASHPTE, 0, 0)); } #define __HAVE_ARCH_PTEP_SET_WRPROTECT static inline void ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep) { pte_update(mm, addr, ptep, _PAGE_RW, 0, 0); } static inline void __ptep_set_access_flags(struct vm_area_struct *vma, pte_t *ptep, pte_t entry, unsigned long address, int psize) { unsigned long set = pte_val(entry) & (_PAGE_DIRTY | _PAGE_ACCESSED | _PAGE_RW | _PAGE_EXEC); pte_update(vma->vm_mm, address, ptep, 0, set, 0); flush_tlb_page(vma, address); } #define __HAVE_ARCH_PTE_SAME #define pte_same(A,B) (((pte_val(A) ^ pte_val(B)) & ~_PAGE_HASHPTE) == 0) #define pmd_pfn(pmd) (pmd_val(pmd) >> PAGE_SHIFT) #define pmd_page(pmd) pfn_to_page(pmd_pfn(pmd)) /* * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that * are !pte_none() && !pte_present(). * * Format of swap PTEs (32bit PTEs): * * 1 1 1 1 1 1 1 1 1 2 2 2 2 2 2 2 2 2 2 3 3 * 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 * <----------------- offset --------------------> < type -> E H P * * E is the exclusive marker that is not stored in swap entries. * _PAGE_PRESENT (P) and __PAGE_HASHPTE (H) must be 0. * * For 64bit PTEs, the offset is extended by 32bit. */ #define __swp_type(entry) ((entry).val & 0x1f) #define __swp_offset(entry) ((entry).val >> 5) #define __swp_entry(type, offset) ((swp_entry_t) { ((type) & 0x1f) | ((offset) << 5) }) #define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) >> 3 }) #define __swp_entry_to_pte(x) ((pte_t) { (x).val << 3 }) static inline int pte_swp_exclusive(pte_t pte) { return pte_val(pte) & _PAGE_SWP_EXCLUSIVE; } static inline pte_t pte_swp_mkexclusive(pte_t pte) { return __pte(pte_val(pte) | _PAGE_SWP_EXCLUSIVE); } static inline pte_t pte_swp_clear_exclusive(pte_t pte) { return __pte(pte_val(pte) & ~_PAGE_SWP_EXCLUSIVE); } /* Generic accessors to PTE bits */ static inline int pte_write(pte_t pte) { return !!(pte_val(pte) & _PAGE_RW);} static inline int pte_read(pte_t pte) { return 1; } static inline int pte_dirty(pte_t pte) { return !!(pte_val(pte) & _PAGE_DIRTY); } static inline int pte_young(pte_t pte) { return !!(pte_val(pte) & _PAGE_ACCESSED); } static inline int pte_special(pte_t pte) { return !!(pte_val(pte) & _PAGE_SPECIAL); } static inline int pte_none(pte_t pte) { return (pte_val(pte) & ~_PTE_NONE_MASK) == 0; } static inline bool pte_exec(pte_t pte) { return pte_val(pte) & _PAGE_EXEC; } static inline int pte_present(pte_t pte) { return pte_val(pte) & _PAGE_PRESENT; } static inline bool pte_hw_valid(pte_t pte) { return pte_val(pte) & _PAGE_PRESENT; } static inline bool pte_hashpte(pte_t pte) { return !!(pte_val(pte) & _PAGE_HASHPTE); } static inline bool pte_ci(pte_t pte) { return !!(pte_val(pte) & _PAGE_NO_CACHE); } /* * We only find page table entry in the last level * Hence no need for other accessors */ #define pte_access_permitted pte_access_permitted static inline bool pte_access_permitted(pte_t pte, bool write) { /* * A read-only access is controlled by _PAGE_USER bit. * We have _PAGE_READ set for WRITE and EXECUTE */ if (!pte_present(pte) || !pte_user(pte) || !pte_read(pte)) return false; if (write && !pte_write(pte)) return false; return true; } /* Conversion functions: convert a page and protection to a page entry, * and a page entry and page directory to the page they refer to. * * Even if PTEs can be unsigned long long, a PFN is always an unsigned * long for now. */ static inline pte_t pfn_pte(unsigned long pfn, pgprot_t pgprot) { return __pte(((pte_basic_t)(pfn) << PTE_RPN_SHIFT) | pgprot_val(pgprot)); } /* Generic modifiers for PTE bits */ static inline pte_t pte_wrprotect(pte_t pte) { return __pte(pte_val(pte) & ~_PAGE_RW); } static inline pte_t pte_exprotect(pte_t pte) { return __pte(pte_val(pte) & ~_PAGE_EXEC); } static inline pte_t pte_mkclean(pte_t pte) { return __pte(pte_val(pte) & ~_PAGE_DIRTY); } static inline pte_t pte_mkold(pte_t pte) { return __pte(pte_val(pte) & ~_PAGE_ACCESSED); } static inline pte_t pte_mkexec(pte_t pte) { return __pte(pte_val(pte) | _PAGE_EXEC); } static inline pte_t pte_mkpte(pte_t pte) { return pte; } static inline pte_t pte_mkwrite_novma(pte_t pte) { return __pte(pte_val(pte) | _PAGE_RW); } static inline pte_t pte_mkdirty(pte_t pte) { return __pte(pte_val(pte) | _PAGE_DIRTY); } static inline pte_t pte_mkyoung(pte_t pte) { return __pte(pte_val(pte) | _PAGE_ACCESSED); } static inline pte_t pte_mkspecial(pte_t pte) { return __pte(pte_val(pte) | _PAGE_SPECIAL); } static inline pte_t pte_mkhuge(pte_t pte) { return pte; } static inline pte_t pte_mkprivileged(pte_t pte) { return __pte(pte_val(pte) & ~_PAGE_USER); } static inline pte_t pte_mkuser(pte_t pte) { return __pte(pte_val(pte) | _PAGE_USER); } static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) { return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot)); } /* This low level function performs the actual PTE insertion * Setting the PTE depends on the MMU type and other factors. * * First case is 32-bit in UP mode with 32-bit PTEs, we need to preserve * the _PAGE_HASHPTE bit since we may not have invalidated the previous * translation in the hash yet (done in a subsequent flush_tlb_xxx()) * and see we need to keep track that this PTE needs invalidating. * * Second case is 32-bit with 64-bit PTE. In this case, we * can just store as long as we do the two halves in the right order * with a barrier in between. This is possible because we take care, * in the hash code, to pre-invalidate if the PTE was already hashed, * which synchronizes us with any concurrent invalidation. * In the percpu case, we fallback to the simple update preserving * the hash bits (ie, same as the non-SMP case). * * Third case is 32-bit in SMP mode with 32-bit PTEs. We use the * helper pte_update() which does an atomic update. We need to do that * because a concurrent invalidation can clear _PAGE_HASHPTE. If it's a * per-CPU PTE such as a kmap_atomic, we also do a simple update preserving * the hash bits instead. */ static inline void __set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte, int percpu) { if ((!IS_ENABLED(CONFIG_SMP) && !IS_ENABLED(CONFIG_PTE_64BIT)) || percpu) { *ptep = __pte((pte_val(*ptep) & _PAGE_HASHPTE) | (pte_val(pte) & ~_PAGE_HASHPTE)); } else if (IS_ENABLED(CONFIG_PTE_64BIT)) { if (pte_val(*ptep) & _PAGE_HASHPTE) flush_hash_entry(mm, ptep, addr); asm volatile("stw%X0 %2,%0; eieio; stw%X1 %L2,%1" : "=m" (*ptep), "=m" (*((unsigned char *)ptep+4)) : "r" (pte) : "memory"); } else { pte_update(mm, addr, ptep, ~_PAGE_HASHPTE, pte_val(pte), 0); } } /* * Macro to mark a page protection value as "uncacheable". */ #define _PAGE_CACHE_CTL (_PAGE_COHERENT | _PAGE_GUARDED | _PAGE_NO_CACHE | \ _PAGE_WRITETHRU) #define pgprot_noncached pgprot_noncached static inline pgprot_t pgprot_noncached(pgprot_t prot) { return __pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | _PAGE_NO_CACHE | _PAGE_GUARDED); } #define pgprot_noncached_wc pgprot_noncached_wc static inline pgprot_t pgprot_noncached_wc(pgprot_t prot) { return __pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | _PAGE_NO_CACHE); } #define pgprot_cached pgprot_cached static inline pgprot_t pgprot_cached(pgprot_t prot) { return __pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | _PAGE_COHERENT); } #define pgprot_cached_wthru pgprot_cached_wthru static inline pgprot_t pgprot_cached_wthru(pgprot_t prot) { return __pgprot((pgprot_val(prot) & ~_PAGE_CACHE_CTL) | _PAGE_COHERENT | _PAGE_WRITETHRU); } #define pgprot_cached_noncoherent pgprot_cached_noncoherent static inline pgprot_t pgprot_cached_noncoherent(pgprot_t prot) { return __pgprot(pgprot_val(prot) & ~_PAGE_CACHE_CTL); } #define pgprot_writecombine pgprot_writecombine static inline pgprot_t pgprot_writecombine(pgprot_t prot) { return pgprot_noncached_wc(prot); } #endif /* !__ASSEMBLY__ */ #endif /* _ASM_POWERPC_BOOK3S_32_PGTABLE_H */