1 files changed, 416 insertions, 0 deletions

diff --git a/arch/xtensa/include/asm/pgtable.h b/arch/xtensa/include/asm/pgtable.h
new file mode 100644
index 00000000000..8014d96b21f
--- /dev/null
+++ b/arch/xtensa/include/asm/pgtable.h
@@ -0,0 +1,416 @@
+/*
+ * include/asm-xtensa/pgtable.h
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Copyright (C) 2001 - 2007 Tensilica Inc.
+ */
+
+#ifndef _XTENSA_PGTABLE_H
+#define _XTENSA_PGTABLE_H
+
+#include <asm-generic/pgtable-nopmd.h>
+#include <asm/page.h>
+
+/*
+ * We only use two ring levels, user and kernel space.
+ */
+
+#define USER_RING               1       /* user ring level */
+#define KERNEL_RING             0       /* kernel ring level */
+
+/*
+ * The Xtensa architecture port of Linux has a two-level page table system,
+ * i.e. the logical three-level Linux page table layout is folded.
+ * Each task has the following memory page tables:
+ *
+ *   PGD table (page directory), ie. 3rd-level page table:
+ *      One page (4 kB) of 1024 (PTRS_PER_PGD) pointers to PTE tables
+ *      (Architectures that don't have the PMD folded point to the PMD tables)
+ *
+ *      The pointer to the PGD table for a given task can be retrieved from
+ *      the task structure (struct task_struct*) t, e.g. current():
+ *        (t->mm ? t->mm : t->active_mm)->pgd
+ *
+ *   PMD tables (page middle-directory), ie. 2nd-level page tables:
+ *      Absent for the Xtensa architecture (folded, PTRS_PER_PMD == 1).
+ *
+ *   PTE tables (page table entry), ie. 1st-level page tables:
+ *      One page (4 kB) of 1024 (PTRS_PER_PTE) PTEs with a special PTE
+ *      invalid_pte_table for absent mappings.
+ *
+ * The individual pages are 4 kB big with special pages for the empty_zero_page.
+ */
+
+#define PGDIR_SHIFT     22
+#define PGDIR_SIZE      (1UL << PGDIR_SHIFT)
+#define PGDIR_MASK      (~(PGDIR_SIZE-1))
+
+/*
+ * Entries per page directory level: we use two-level, so
+ * we don't really have any PMD directory physically.
+ */
+#define PTRS_PER_PTE            1024
+#define PTRS_PER_PTE_SHIFT      10
+#define PTRS_PER_PGD            1024
+#define PGD_ORDER               0
+#define USER_PTRS_PER_PGD       (TASK_SIZE/PGDIR_SIZE)
+#define FIRST_USER_ADDRESS      0
+#define FIRST_USER_PGD_NR       (FIRST_USER_ADDRESS >> PGDIR_SHIFT)
+
+/*
+ * Virtual memory area. We keep a distance to other memory regions to be
+ * on the safe side. We also use this area for cache aliasing.
+ */
+
+#define VMALLOC_START           0xC0000000
+#define VMALLOC_END             0xC7FEFFFF
+#define TLBTEMP_BASE_1          0xC7FF0000
+#define TLBTEMP_BASE_2          0xC7FF8000
+
+/*
+ * Xtensa Linux config PTE layout (when present):
+ *      31-12:  PPN
+ *      11-6:   Software
+ *      5-4:    RING
+ *      3-0:    CA
+ *
+ * Similar to the Alpha and MIPS ports, we need to keep track of the ref
+ * and mod bits in software.  We have a software "you can read
+ * from this page" bit, and a hardware one which actually lets the
+ * process read from the page.  On the same token we have a software
+ * writable bit and the real hardware one which actually lets the
+ * process write to the page.
+ *
+ * See further below for PTE layout for swapped-out pages.
+ */
+
+#define _PAGE_HW_EXEC           (1<<0)  /* hardware: page is executable */
+#define _PAGE_HW_WRITE          (1<<1)  /* hardware: page is writable */
+
+#define _PAGE_FILE              (1<<1)  /* non-linear mapping, if !present */
+#define _PAGE_PROTNONE          (3<<0)  /* special case for VM_PROT_NONE */
+
+/* None of these cache modes include MP coherency:  */
+#define _PAGE_CA_BYPASS         (0<<2)  /* bypass, non-speculative */
+#define _PAGE_CA_WB             (1<<2)  /* write-back */
+#define _PAGE_CA_WT             (2<<2)  /* write-through */
+#define _PAGE_CA_MASK           (3<<2)
+#define _PAGE_INVALID           (3<<2)
+
+#define _PAGE_USER              (1<<4)  /* user access (ring=1) */
+
+/* Software */
+#define _PAGE_WRITABLE_BIT      6
+#define _PAGE_WRITABLE          (1<<6)  /* software: page writable */
+#define _PAGE_DIRTY             (1<<7)  /* software: page dirty */
+#define _PAGE_ACCESSED          (1<<8)  /* software: page accessed (read) */
+
+/* On older HW revisions, we always have to set bit 0 */
+#if XCHAL_HW_VERSION_MAJOR < 2000
+# define _PAGE_VALID            (1<<0)
+#else
+# define _PAGE_VALID            0
+#endif
+
+#define _PAGE_CHG_MASK  (PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)
+#define _PAGE_PRESENT   (_PAGE_VALID | _PAGE_CA_WB | _PAGE_ACCESSED)
+
+#ifdef CONFIG_MMU
+
+#define PAGE_NONE          __pgprot(_PAGE_INVALID | _PAGE_USER | _PAGE_PROTNONE)
+#define PAGE_COPY          __pgprot(_PAGE_PRESENT | _PAGE_USER)
+#define PAGE_COPY_EXEC     __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_HW_EXEC)
+#define PAGE_READONLY      __pgprot(_PAGE_PRESENT | _PAGE_USER)
+#define PAGE_READONLY_EXEC __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_HW_EXEC)
+#define PAGE_SHARED        __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_WRITABLE)
+#define PAGE_SHARED_EXEC \
+        __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_WRITABLE | _PAGE_HW_EXEC)
+#define PAGE_KERNEL        __pgprot(_PAGE_PRESENT | _PAGE_HW_WRITE)
+#define PAGE_KERNEL_EXEC   __pgprot(_PAGE_PRESENT|_PAGE_HW_WRITE|_PAGE_HW_EXEC)
+
+#if (DCACHE_WAY_SIZE > PAGE_SIZE)
+# define _PAGE_DIRECTORY (_PAGE_VALID | _PAGE_ACCESSED)
+#else
+# define _PAGE_DIRECTORY (_PAGE_VALID | _PAGE_ACCESSED | _PAGE_CA_WB)
+#endif
+
+#else /* no mmu */
+
+# define PAGE_NONE       __pgprot(0)
+# define PAGE_SHARED     __pgprot(0)
+# define PAGE_COPY       __pgprot(0)
+# define PAGE_READONLY   __pgprot(0)
+# define PAGE_KERNEL     __pgprot(0)
+
+#endif
+
+/*
+ * On certain configurations of Xtensa MMUs (eg. the initial Linux config),
+ * the MMU can't do page protection for execute, and considers that the same as
+ * read.  Also, write permissions may imply read permissions.
+ * What follows is the closest we can get by reasonable means..
+ * See linux/mm/mmap.c for protection_map[] array that uses these definitions.
+ */
+#define __P000  PAGE_NONE               /* private --- */
+#define __P001  PAGE_READONLY           /* private --r */
+#define __P010  PAGE_COPY               /* private -w- */
+#define __P011  PAGE_COPY               /* private -wr */
+#define __P100  PAGE_READONLY_EXEC      /* private x-- */
+#define __P101  PAGE_READONLY_EXEC      /* private x-r */
+#define __P110  PAGE_COPY_EXEC          /* private xw- */
+#define __P111  PAGE_COPY_EXEC          /* private xwr */
+
+#define __S000  PAGE_NONE               /* shared  --- */
+#define __S001  PAGE_READONLY           /* shared  --r */
+#define __S010  PAGE_SHARED             /* shared  -w- */
+#define __S011  PAGE_SHARED             /* shared  -wr */
+#define __S100  PAGE_READONLY_EXEC      /* shared  x-- */
+#define __S101  PAGE_READONLY_EXEC      /* shared  x-r */
+#define __S110  PAGE_SHARED_EXEC        /* shared  xw- */
+#define __S111  PAGE_SHARED_EXEC        /* shared  xwr */
+
+#ifndef __ASSEMBLY__
+
+#define pte_ERROR(e) \
+        printk("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, pte_val(e))
+#define pgd_ERROR(e) \
+        printk("%s:%d: bad pgd entry %08lx.\n", __FILE__, __LINE__, pgd_val(e))
+
+extern unsigned long empty_zero_page[1024];
+
+#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
+
+extern pgd_t swapper_pg_dir[PAGE_SIZE/sizeof(pgd_t)];
+
+/*
+ * The pmd contains the kernel virtual address of the pte page.
+ */
+#define pmd_page_vaddr(pmd) ((unsigned long)(pmd_val(pmd) & PAGE_MASK))
+#define pmd_page(pmd) virt_to_page(pmd_val(pmd))
+
+/*
+ * pte status.
+ */
+#define pte_none(pte)    (pte_val(pte) == _PAGE_INVALID)
+#define pte_present(pte)                                                \
+        (((pte_val(pte) & _PAGE_CA_MASK) != _PAGE_INVALID)              \
+         || ((pte_val(pte) & _PAGE_PROTNONE) == _PAGE_PROTNONE))
+#define pte_clear(mm,addr,ptep)                                         \
+        do { update_pte(ptep, __pte(_PAGE_INVALID)); } while(0)
+
+#define pmd_none(pmd)    (!pmd_val(pmd))
+#define pmd_present(pmd) (pmd_val(pmd) & PAGE_MASK)
+#define pmd_bad(pmd)     (pmd_val(pmd) & ~PAGE_MASK)
+#define pmd_clear(pmdp)  do { set_pmd(pmdp, __pmd(0)); } while (0)
+
+static inline int pte_write(pte_t pte) { return pte_val(pte) & _PAGE_WRITABLE; }
+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_file(pte_t pte)  { return pte_val(pte) & _PAGE_FILE; }
+static inline int pte_special(pte_t pte) { return 0; }
+
+static inline pte_t pte_wrprotect(pte_t pte)    
+        { pte_val(pte) &= ~(_PAGE_WRITABLE | _PAGE_HW_WRITE); return pte; }
+static inline pte_t pte_mkclean(pte_t pte)
+        { pte_val(pte) &= ~(_PAGE_DIRTY | _PAGE_HW_WRITE); return pte; }
+static inline pte_t pte_mkold(pte_t pte)
+        { pte_val(pte) &= ~_PAGE_ACCESSED; 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_mkwrite(pte_t pte)
+        { pte_val(pte) |= _PAGE_WRITABLE; return pte; }
+static inline pte_t pte_mkspecial(pte_t pte)
+        { return pte; }
+
+/*
+ * 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 pte_pfn(pte)            (pte_val(pte) >> PAGE_SHIFT)
+#define pte_same(a,b)           (pte_val(a) == pte_val(b))
+#define pte_page(x)             pfn_to_page(pte_pfn(x))
+#define pfn_pte(pfn, prot)      __pte(((pfn) << PAGE_SHIFT) | pgprot_val(prot))
+#define mk_pte(page, prot)      pfn_pte(page_to_pfn(page), prot)
+
+static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
+{
+        return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot));
+}
+
+/*
+ * Certain architectures need to do special things when pte's
+ * within a page table are directly modified.  Thus, the following
+ * hook is made available.
+ */
+static inline void update_pte(pte_t *ptep, pte_t pteval)
+{
+        *ptep = pteval;
+#if (DCACHE_WAY_SIZE > PAGE_SIZE) && XCHAL_DCACHE_IS_WRITEBACK
+        __asm__ __volatile__ ("dhwb %0, 0" :: "a" (ptep));
+#endif
+
+}
+
+struct mm_struct;
+
+static inline void
+set_pte_at(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pteval)
+{
+        update_pte(ptep, pteval);
+}
+
+
+static inline void
+set_pmd(pmd_t *pmdp, pmd_t pmdval)
+{
+        *pmdp = pmdval;
+}
+
+struct vm_area_struct;
+
+static inline int
+ptep_test_and_clear_young(struct vm_area_struct *vma, unsigned long addr,
+                          pte_t *ptep)
+{
+        pte_t pte = *ptep;
+        if (!pte_young(pte))
+                return 0;
+        update_pte(ptep, pte_mkold(pte));
+        return 1;
+}
+
+static inline pte_t
+ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
+{
+        pte_t pte = *ptep;
+        pte_clear(mm, addr, ptep);
+        return pte;
+}
+
+static inline void
+ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
+{
+        pte_t pte = *ptep;
+        update_pte(ptep, pte_wrprotect(pte));
+}
+
+/* to find an entry in a kernel page-table-directory */
+#define pgd_offset_k(address)   pgd_offset(&init_mm, address)
+
+/* to find an entry in a page-table-directory */
+#define pgd_offset(mm,address)  ((mm)->pgd + pgd_index(address))
+
+#define pgd_index(address)      ((address) >> PGDIR_SHIFT)
+
+/* Find an entry in the second-level page table.. */
+#define pmd_offset(dir,address) ((pmd_t*)(dir))
+
+/* Find an entry in the third-level page table.. */
+#define pte_index(address)      (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
+#define pte_offset_kernel(dir,addr)                                     \
+        ((pte_t*) pmd_page_vaddr(*(dir)) + pte_index(addr))
+#define pte_offset_map(dir,addr)        pte_offset_kernel((dir),(addr))
+#define pte_offset_map_nested(dir,addr) pte_offset_kernel((dir),(addr))
+
+#define pte_unmap(pte)          do { } while (0)
+#define pte_unmap_nested(pte)   do { } while (0)
+
+
+/*
+ * Encode and decode a swap entry.
+ *
+ * Format of swap pte:
+ *  bit    0       MBZ
+ *  bit    1       page-file (must be zero)
+ *  bits   2 -  3  page hw access mode (must be 11: _PAGE_INVALID)
+ *  bits   4 -  5  ring protection (must be 01: _PAGE_USER)
+ *  bits   6 - 10  swap type (5 bits -> 32 types)
+ *  bits  11 - 31  swap offset / PAGE_SIZE (21 bits -> 8GB)
+ 
+ * Format of file pte:
+ *  bit    0       MBZ
+ *  bit    1       page-file (must be one: _PAGE_FILE)
+ *  bits   2 -  3  page hw access mode (must be 11: _PAGE_INVALID)
+ *  bits   4 -  5  ring protection (must be 01: _PAGE_USER)
+ *  bits   6 - 31  file offset / PAGE_SIZE
+ */
+
+#define __swp_type(entry)       (((entry).val >> 6) & 0x1f)
+#define __swp_offset(entry)     ((entry).val >> 11)
+#define __swp_entry(type,offs)  \
+        ((swp_entry_t) {((type) << 6) | ((offs) << 11) | _PAGE_INVALID})
+#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
+#define __swp_entry_to_pte(x)   ((pte_t) { (x).val })
+
+#define PTE_FILE_MAX_BITS       28
+#define pte_to_pgoff(pte)       (pte_val(pte) >> 4)
+#define pgoff_to_pte(off)       \
+        ((pte_t) { ((off) << 4) | _PAGE_INVALID | _PAGE_FILE })
+
+#endif /*  !defined (__ASSEMBLY__) */
+
+
+#ifdef __ASSEMBLY__
+
+/* Assembly macro _PGD_INDEX is the same as C pgd_index(unsigned long),
+ *                _PGD_OFFSET as C pgd_offset(struct mm_struct*, unsigned long),
+ *                _PMD_OFFSET as C pmd_offset(pgd_t*, unsigned long)
+ *                _PTE_OFFSET as C pte_offset(pmd_t*, unsigned long)
+ *
+ * Note: We require an additional temporary register which can be the same as
+ *       the register that holds the address.
+ *
+ * ((pte_t*) ((unsigned long)(pmd_val(*pmd) & PAGE_MASK)) + pte_index(addr))
+ *
+ */
+#define _PGD_INDEX(rt,rs)       extui   rt, rs, PGDIR_SHIFT, 32-PGDIR_SHIFT
+#define _PTE_INDEX(rt,rs)       extui   rt, rs, PAGE_SHIFT, PTRS_PER_PTE_SHIFT
+
+#define _PGD_OFFSET(mm,adr,tmp)         l32i    mm, mm, MM_PGD;         \
+                                        _PGD_INDEX(tmp, adr);           \
+                                        addx4   mm, tmp, mm
+
+#define _PTE_OFFSET(pmd,adr,tmp)        _PTE_INDEX(tmp, adr);           \
+                                        srli    pmd, pmd, PAGE_SHIFT;   \
+                                        slli    pmd, pmd, PAGE_SHIFT;   \
+                                        addx4   pmd, tmp, pmd
+
+#else
+
+extern void paging_init(void);
+
+#define kern_addr_valid(addr)   (1)
+
+extern  void update_mmu_cache(struct vm_area_struct * vma,
+                              unsigned long address, pte_t pte);
+
+/*
+ * remap a physical page `pfn' of size `size' with page protection `prot'
+ * into virtual address `from'
+ */
+
+#define io_remap_pfn_range(vma,from,pfn,size,prot) \
+                remap_pfn_range(vma, from, pfn, size, prot)
+
+
+extern void pgtable_cache_init(void);
+
+typedef pte_t *pte_addr_t;
+
+#endif /* !defined (__ASSEMBLY__) */
+
+#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
+#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
+#define __HAVE_ARCH_PTEP_SET_WRPROTECT
+#define __HAVE_ARCH_PTEP_MKDIRTY
+#define __HAVE_ARCH_PTE_SAME
+
+#include <asm-generic/pgtable.h>
+
+#endif /* _XTENSA_PGTABLE_H */