--- /dev/null
+/*
+ * Macros and functions to manipulate Meta page tables.
+ */
+
+#ifndef _METAG_PGTABLE_H
+#define _METAG_PGTABLE_H
+
+#include <asm/pgtable-bits.h>
+#include <asm-generic/pgtable-nopmd.h>
+
+/* 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 <asm/page.h>
+
+/* 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 <asm-generic/pgtable.h>
+
+#endif /* __ASSEMBLY__ */
+#endif /* _METAG_PGTABLE_H */
Code Review / kvmfornfv.git / blobdiff