From 57f0f512b273f60d52568b8c6b77e17f5636edc0 Mon Sep 17 00:00:00 2001 From: André Fabian Silva Delgado Date: Wed, 5 Aug 2015 17:04:01 -0300 Subject: Initial import --- arch/metag/include/asm/pgtable.h | 268 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 268 insertions(+) create mode 100644 arch/metag/include/asm/pgtable.h (limited to 'arch/metag/include/asm/pgtable.h') diff --git a/arch/metag/include/asm/pgtable.h b/arch/metag/include/asm/pgtable.h new file mode 100644 index 000000000..ffa3a3a2e --- /dev/null +++ b/arch/metag/include/asm/pgtable.h @@ -0,0 +1,268 @@ +/* + * Macros and functions to manipulate Meta page tables. + */ + +#ifndef _METAG_PGTABLE_H +#define _METAG_PGTABLE_H + +#include +#include + +/* Invalid regions on Meta: 0x00000000-0x001FFFFF and 0xFFFF0000-0xFFFFFFFF */ +#if PAGE_OFFSET >= LINGLOBAL_BASE +#define CONSISTENT_START 0xF7000000 +#define CONSISTENT_END 0xF73FFFFF +#define VMALLOC_START 0xF8000000 +#define VMALLOC_END 0xFFFEFFFF +#else +#define CONSISTENT_START 0x77000000 +#define CONSISTENT_END 0x773FFFFF +#define VMALLOC_START 0x78000000 +#define VMALLOC_END 0x7FFFFFFF +#endif + +/* + * The Linux memory management assumes a three-level page table setup. On + * Meta, we use that, but "fold" the mid level into the top-level page + * table. + */ + +/* PGDIR_SHIFT determines the size of the area a second-level page table can + * map. This is always 4MB. + */ + +#define PGDIR_SHIFT 22 +#define PGDIR_SIZE (1UL << PGDIR_SHIFT) +#define PGDIR_MASK (~(PGDIR_SIZE-1)) + +/* + * Entries per page directory level: we use a two-level, so + * we don't really have any PMD directory physically. First level tables + * always map 2Gb (local or global) at a granularity of 4MB, second-level + * tables map 4MB with a granularity between 4MB and 4kB (between 1 and + * 1024 entries). + */ +#define PTRS_PER_PTE (PGDIR_SIZE/PAGE_SIZE) +#define HPTRS_PER_PTE (PGDIR_SIZE/HPAGE_SIZE) +#define PTRS_PER_PGD 512 + +#define USER_PTRS_PER_PGD 256 +#define FIRST_USER_ADDRESS META_MEMORY_BASE +#define FIRST_USER_PGD_NR pgd_index(FIRST_USER_ADDRESS) + +#define PAGE_NONE __pgprot(_PAGE_PRESENT | _PAGE_ACCESSED | \ + _PAGE_CACHEABLE) + +#define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_WRITE | \ + _PAGE_ACCESSED | _PAGE_CACHEABLE) +#define PAGE_SHARED_C PAGE_SHARED +#define PAGE_COPY __pgprot(_PAGE_PRESENT | _PAGE_ACCESSED | \ + _PAGE_CACHEABLE) +#define PAGE_COPY_C PAGE_COPY + +#define PAGE_READONLY __pgprot(_PAGE_PRESENT | _PAGE_ACCESSED | \ + _PAGE_CACHEABLE) +#define PAGE_KERNEL __pgprot(_PAGE_PRESENT | _PAGE_DIRTY | \ + _PAGE_ACCESSED | _PAGE_WRITE | \ + _PAGE_CACHEABLE | _PAGE_KERNEL) + +#define __P000 PAGE_NONE +#define __P001 PAGE_READONLY +#define __P010 PAGE_COPY +#define __P011 PAGE_COPY +#define __P100 PAGE_READONLY +#define __P101 PAGE_READONLY +#define __P110 PAGE_COPY_C +#define __P111 PAGE_COPY_C + +#define __S000 PAGE_NONE +#define __S001 PAGE_READONLY +#define __S010 PAGE_SHARED +#define __S011 PAGE_SHARED +#define __S100 PAGE_READONLY +#define __S101 PAGE_READONLY +#define __S110 PAGE_SHARED_C +#define __S111 PAGE_SHARED_C + +#ifndef __ASSEMBLY__ + +#include + +/* zero page used for uninitialized stuff */ +extern unsigned long empty_zero_page; +#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page)) + +/* Certain architectures need to do special things when pte's + * within a page table are directly modified. Thus, the following + * hook is made available. + */ +#define set_pte(pteptr, pteval) ((*(pteptr)) = (pteval)) +#define set_pte_at(mm, addr, ptep, pteval) set_pte(ptep, pteval) + +#define set_pmd(pmdptr, pmdval) (*(pmdptr) = pmdval) + +#define pte_pfn(pte) (pte_val(pte) >> PAGE_SHIFT) + +#define pfn_pte(pfn, prot) __pte(((pfn) << PAGE_SHIFT) | pgprot_val(prot)) + +#define pte_none(x) (!pte_val(x)) +#define pte_present(x) (pte_val(x) & _PAGE_PRESENT) +#define pte_clear(mm, addr, xp) do { pte_val(*(xp)) = 0; } while (0) + +#define pmd_none(x) (!pmd_val(x)) +#define pmd_bad(x) ((pmd_val(x) & ~(PAGE_MASK | _PAGE_SZ_MASK)) \ + != (_PAGE_TABLE & ~_PAGE_SZ_MASK)) +#define pmd_present(x) (pmd_val(x) & _PAGE_PRESENT) +#define pmd_clear(xp) do { pmd_val(*(xp)) = 0; } while (0) + +#define pte_page(x) pfn_to_page(pte_pfn(x)) + +/* + * The following only work if pte_present() is true. + * Undefined behaviour if not.. + */ + +static inline int pte_write(pte_t pte) { return pte_val(pte) & _PAGE_WRITE; } +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 0; } + +static inline pte_t pte_wrprotect(pte_t pte) { pte_val(pte) &= (~_PAGE_WRITE); return pte; } +static inline pte_t pte_mkclean(pte_t pte) { pte_val(pte) &= ~_PAGE_DIRTY; return pte; } +static inline pte_t pte_mkold(pte_t pte) { pte_val(pte) &= ~_PAGE_ACCESSED; return pte; } +static inline pte_t pte_mkwrite(pte_t pte) { pte_val(pte) |= _PAGE_WRITE; return pte; } +static inline pte_t pte_mkdirty(pte_t pte) { pte_val(pte) |= _PAGE_DIRTY; return pte; } +static inline pte_t pte_mkyoung(pte_t pte) { pte_val(pte) |= _PAGE_ACCESSED; return pte; } +static inline pte_t pte_mkspecial(pte_t pte) { return pte; } +static inline pte_t pte_mkhuge(pte_t pte) { return pte; } + +/* + * Macro and implementation to make a page protection as uncacheable. + */ +#define pgprot_writecombine(prot) \ + __pgprot(pgprot_val(prot) & ~(_PAGE_CACHE_CTRL1 | _PAGE_CACHE_CTRL0)) + +#define pgprot_noncached(prot) \ + __pgprot(pgprot_val(prot) & ~_PAGE_CACHEABLE) + + +/* + * Conversion functions: convert a page and protection to a page entry, + * and a page entry and page directory to the page they refer to. + */ + +#define mk_pte(page, pgprot) pfn_pte(page_to_pfn(page), (pgprot)) + +static inline pte_t pte_modify(pte_t pte, pgprot_t newprot) +{ + pte_val(pte) = (pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot); + return pte; +} + +static inline unsigned long pmd_page_vaddr(pmd_t pmd) +{ + unsigned long paddr = pmd_val(pmd) & PAGE_MASK; + if (!paddr) + return 0; + return (unsigned long)__va(paddr); +} + +#define pmd_page(pmd) (pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT)) +#define pmd_page_shift(pmd) (12 + ((pmd_val(pmd) & _PAGE_SZ_MASK) \ + >> _PAGE_SZ_SHIFT)) +#define pmd_num_ptrs(pmd) (PGDIR_SIZE >> pmd_page_shift(pmd)) + +/* + * Each pgd is only 2k, mapping 2Gb (local or global). If we're in global + * space drop the top bit before indexing the pgd. + */ +#if PAGE_OFFSET >= LINGLOBAL_BASE +#define pgd_index(address) ((((address) & ~0x80000000) >> PGDIR_SHIFT) \ + & (PTRS_PER_PGD-1)) +#else +#define pgd_index(address) (((address) >> PGDIR_SHIFT) & (PTRS_PER_PGD-1)) +#endif + +#define pgd_offset(mm, address) ((mm)->pgd + pgd_index(address)) + +#define pgd_offset_k(address) pgd_offset(&init_mm, address) + +#define pmd_index(address) (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1)) + +/* Find an entry in the second-level page table.. */ +#if !defined(CONFIG_HUGETLB_PAGE) + /* all pages are of size (1 << PAGE_SHIFT), so no need to read 1st level pt */ +# define pte_index(pmd, address) \ + (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) +#else + /* some pages are huge, so read 1st level pt to find out */ +# define pte_index(pmd, address) \ + (((address) >> pmd_page_shift(pmd)) & (pmd_num_ptrs(pmd) - 1)) +#endif +#define pte_offset_kernel(dir, address) \ + ((pte_t *) pmd_page_vaddr(*(dir)) + pte_index(*(dir), address)) +#define pte_offset_map(dir, address) pte_offset_kernel(dir, address) +#define pte_offset_map_nested(dir, address) pte_offset_kernel(dir, address) + +#define pte_unmap(pte) do { } while (0) +#define pte_unmap_nested(pte) do { } while (0) + +#define pte_ERROR(e) \ + pr_err("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, pte_val(e)) +#define pgd_ERROR(e) \ + pr_err("%s:%d: bad pgd %08lx.\n", __FILE__, __LINE__, pgd_val(e)) + +/* + * Meta doesn't have any external MMU info: the kernel page + * tables contain all the necessary information. + */ +static inline void update_mmu_cache(struct vm_area_struct *vma, + unsigned long address, pte_t *pte) +{ +} + +/* + * Encode and decode a swap entry (must be !pte_none(e) && !pte_present(e)) + * Since PAGE_PRESENT is bit 1, we can use the bits above that. + */ +#define __swp_type(x) (((x).val >> 1) & 0xff) +#define __swp_offset(x) ((x).val >> 10) +#define __swp_entry(type, offset) ((swp_entry_t) { ((type) << 1) | \ + ((offset) << 10) }) +#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) +#define __swp_entry_to_pte(x) ((pte_t) { (x).val }) + +#define kern_addr_valid(addr) (1) + +/* + * No page table caches to initialise + */ +#define pgtable_cache_init() do { } while (0) + +extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; +void paging_init(unsigned long mem_end); + +#ifdef CONFIG_METAG_META12 +/* This is a workaround for an issue in Meta 1 cores. These cores cache + * invalid entries in the TLB so we always need to flush whenever we add + * a new pte. Unfortunately we can only flush the whole TLB not shoot down + * single entries so this is sub-optimal. This implementation ensures that + * we will get a flush at the second attempt, so we may still get repeated + * faults, we just don't overflow the kernel stack handling them. + */ +#define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS +#define ptep_set_access_flags(__vma, __address, __ptep, __entry, __dirty) \ +({ \ + int __changed = !pte_same(*(__ptep), __entry); \ + if (__changed) { \ + set_pte_at((__vma)->vm_mm, (__address), __ptep, __entry); \ + } \ + flush_tlb_page(__vma, __address); \ + __changed; \ +}) +#endif + +#include + +#endif /* __ASSEMBLY__ */ +#endif /* _METAG_PGTABLE_H */ -- cgit v1.2.3-54-g00ecf