--- /dev/null
+/*
+ * arch/arm/include/asm/pgtable.h
+ *
+ * Copyright (C) 1995-2002 Russell King
+ *
+ * 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.
+ */
+#ifndef _ASMARM_PGTABLE_H
+#define _ASMARM_PGTABLE_H
+
+#include <linux/const.h>
+#include <asm-generic/4level-fixup.h>
+#include <asm/proc-fns.h>
+
+#ifndef CONFIG_MMU
+
+#include "pgtable-nommu.h"
+
+#else
+
+#include <asm/memory.h>
+#include <mach/vmalloc.h>
+#include <asm/pgtable-hwdef.h>
+
+/*
+ * Just any arbitrary offset to the start of the vmalloc VM area: the
+ * current 8MB value just means that there will be a 8MB "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. ;)
+ *
+ * Note that platforms may override VMALLOC_START, but they must provide
+ * VMALLOC_END. VMALLOC_END defines the (exclusive) limit of this space,
+ * which may not overlap IO space.
+ */
+#ifndef VMALLOC_START
+#define VMALLOC_OFFSET (8*1024*1024)
+#define VMALLOC_START (((unsigned long)high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))
+#endif
+
+/*
+ * Hardware-wise, we have a two level page table structure, where the first
+ * level has 4096 entries, and the second level has 256 entries. Each entry
+ * is one 32-bit word. Most of the bits in the second level entry are used
+ * by hardware, and there aren't any "accessed" and "dirty" bits.
+ *
+ * Linux on the other hand has a three level page table structure, which can
+ * be wrapped to fit a two level page table structure easily - using the PGD
+ * and PTE only. However, Linux also expects one "PTE" table per page, and
+ * at least a "dirty" bit.
+ *
+ * Therefore, we tweak the implementation slightly - we tell Linux that we
+ * have 2048 entries in the first level, each of which is 8 bytes (iow, two
+ * hardware pointers to the second level.) The second level contains two
+ * hardware PTE tables arranged contiguously, preceded by Linux versions
+ * which contain the state information Linux needs. We, therefore, end up
+ * with 512 entries in the "PTE" level.
+ *
+ * This leads to the page tables having the following layout:
+ *
+ * pgd pte
+ * | |
+ * +--------+
+ * | | +------------+ +0
+ * +- - - - + | Linux pt 0 |
+ * | | +------------+ +1024
+ * +--------+ +0 | Linux pt 1 |
+ * | |-----> +------------+ +2048
+ * +- - - - + +4 | h/w pt 0 |
+ * | |-----> +------------+ +3072
+ * +--------+ +8 | h/w pt 1 |
+ * | | +------------+ +4096
+ *
+ * See L_PTE_xxx below for definitions of bits in the "Linux pt", and
+ * PTE_xxx for definitions of bits appearing in the "h/w pt".
+ *
+ * PMD_xxx definitions refer to bits in the first level page table.
+ *
+ * The "dirty" bit is emulated by only granting hardware write permission
+ * iff the page is marked "writable" and "dirty" in the Linux PTE. This
+ * means that a write to a clean page will cause a permission fault, and
+ * the Linux MM layer will mark the page dirty via handle_pte_fault().
+ * For the hardware to notice the permission change, the TLB entry must
+ * be flushed, and ptep_set_access_flags() does that for us.
+ *
+ * The "accessed" or "young" bit is emulated by a similar method; we only
+ * allow accesses to the page if the "young" bit is set. Accesses to the
+ * page will cause a fault, and handle_pte_fault() will set the young bit
+ * for us as long as the page is marked present in the corresponding Linux
+ * PTE entry. Again, ptep_set_access_flags() will ensure that the TLB is
+ * up to date.
+ *
+ * However, when the "young" bit is cleared, we deny access to the page
+ * by clearing the hardware PTE. Currently Linux does not flush the TLB
+ * for us in this case, which means the TLB will retain the transation
+ * until either the TLB entry is evicted under pressure, or a context
+ * switch which changes the user space mapping occurs.
+ */
+#define PTRS_PER_PTE 512
+#define PTRS_PER_PMD 1
+#define PTRS_PER_PGD 2048
+
+#define PTE_HWTABLE_PTRS (PTRS_PER_PTE)
+#define PTE_HWTABLE_OFF (PTE_HWTABLE_PTRS * sizeof(pte_t))
+#define PTE_HWTABLE_SIZE (PTRS_PER_PTE * sizeof(u32))
+
+/*
+ * PMD_SHIFT determines the size of the area a second-level page table can map
+ * PGDIR_SHIFT determines what a third-level page table entry can map
+ */
+#define PMD_SHIFT 21
+#define PGDIR_SHIFT 21
+
+#define LIBRARY_TEXT_START 0x0c000000
+
+#ifndef __ASSEMBLY__
+extern void __pte_error(const char *file, int line, pte_t);
+extern void __pmd_error(const char *file, int line, pmd_t);
+extern void __pgd_error(const char *file, int line, pgd_t);
+
+#define pte_ERROR(pte) __pte_error(__FILE__, __LINE__, pte)
+#define pmd_ERROR(pmd) __pmd_error(__FILE__, __LINE__, pmd)
+#define pgd_ERROR(pgd) __pgd_error(__FILE__, __LINE__, pgd)
+#endif /* !__ASSEMBLY__ */
+
+#define PMD_SIZE (1UL << PMD_SHIFT)
+#define PMD_MASK (~(PMD_SIZE-1))
+#define PGDIR_SIZE (1UL << PGDIR_SHIFT)
+#define PGDIR_MASK (~(PGDIR_SIZE-1))
+
+/*
+ * This is the lowest virtual address we can permit any user space
+ * mapping to be mapped at. This is particularly important for
+ * non-high vector CPUs.
+ */
+#define FIRST_USER_ADDRESS PAGE_SIZE
+
+#define USER_PTRS_PER_PGD (TASK_SIZE / PGDIR_SIZE)
+
+/*
+ * section address mask and size definitions.
+ */
+#define SECTION_SHIFT 20
+#define SECTION_SIZE (1UL << SECTION_SHIFT)
+#define SECTION_MASK (~(SECTION_SIZE-1))
+
+/*
+ * ARMv6 supersection address mask and size definitions.
+ */
+#define SUPERSECTION_SHIFT 24
+#define SUPERSECTION_SIZE (1UL << SUPERSECTION_SHIFT)
+#define SUPERSECTION_MASK (~(SUPERSECTION_SIZE-1))
+
+/*
+ * "Linux" PTE definitions.
+ *
+ * We keep two sets of PTEs - the hardware and the linux version.
+ * This allows greater flexibility in the way we map the Linux bits
+ * onto the hardware tables, and allows us to have YOUNG and DIRTY
+ * bits.
+ *
+ * The PTE table pointer refers to the hardware entries; the "Linux"
+ * entries are stored 1024 bytes below.
+ */
+#define L_PTE_PRESENT (_AT(pteval_t, 1) << 0)
+#define L_PTE_YOUNG (_AT(pteval_t, 1) << 1)
+#define L_PTE_FILE (_AT(pteval_t, 1) << 2) /* only when !PRESENT */
+#define L_PTE_DIRTY (_AT(pteval_t, 1) << 6)
+#define L_PTE_RDONLY (_AT(pteval_t, 1) << 7)
+#define L_PTE_USER (_AT(pteval_t, 1) << 8)
+#define L_PTE_XN (_AT(pteval_t, 1) << 9)
+#define L_PTE_SHARED (_AT(pteval_t, 1) << 10) /* shared(v6), coherent(xsc3) */
+
+/*
+ * These are the memory types, defined to be compatible with
+ * pre-ARMv6 CPUs cacheable and bufferable bits: XXCB
+ */
+#define L_PTE_MT_UNCACHED (_AT(pteval_t, 0x00) << 2) /* 0000 */
+#define L_PTE_MT_BUFFERABLE (_AT(pteval_t, 0x01) << 2) /* 0001 */
+#define L_PTE_MT_WRITETHROUGH (_AT(pteval_t, 0x02) << 2) /* 0010 */
+#define L_PTE_MT_WRITEBACK (_AT(pteval_t, 0x03) << 2) /* 0011 */
+#define L_PTE_MT_MINICACHE (_AT(pteval_t, 0x06) << 2) /* 0110 (sa1100, xscale) */
+#define L_PTE_MT_WRITEALLOC (_AT(pteval_t, 0x07) << 2) /* 0111 */
+#define L_PTE_MT_DEV_SHARED (_AT(pteval_t, 0x04) << 2) /* 0100 */
+#define L_PTE_MT_DEV_NONSHARED (_AT(pteval_t, 0x0c) << 2) /* 1100 */
+#define L_PTE_MT_DEV_WC (_AT(pteval_t, 0x09) << 2) /* 1001 */
+#define L_PTE_MT_DEV_CACHED (_AT(pteval_t, 0x0b) << 2) /* 1011 */
+#define L_PTE_MT_MASK (_AT(pteval_t, 0x0f) << 2)
+
+#ifndef __ASSEMBLY__
+
+/*
+ * The pgprot_* and protection_map entries will be fixed up in runtime
+ * to include the cachable and bufferable bits based on memory policy,
+ * as well as any architecture dependent bits like global/ASID and SMP
+ * shared mapping bits.
+ */
+#define _L_PTE_DEFAULT L_PTE_PRESENT | L_PTE_YOUNG
+
+extern pgprot_t pgprot_user;
+extern pgprot_t pgprot_kernel;
+
+#define _MOD_PROT(p, b) __pgprot(pgprot_val(p) | (b))
+
+#define PAGE_NONE _MOD_PROT(pgprot_user, L_PTE_XN | L_PTE_RDONLY)
+#define PAGE_SHARED _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_XN)
+#define PAGE_SHARED_EXEC _MOD_PROT(pgprot_user, L_PTE_USER)
+#define PAGE_COPY _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
+#define PAGE_COPY_EXEC _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY)
+#define PAGE_READONLY _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
+#define PAGE_READONLY_EXEC _MOD_PROT(pgprot_user, L_PTE_USER | L_PTE_RDONLY)
+#define PAGE_KERNEL _MOD_PROT(pgprot_kernel, L_PTE_XN)
+#define PAGE_KERNEL_EXEC pgprot_kernel
+
+#define __PAGE_NONE __pgprot(_L_PTE_DEFAULT | L_PTE_RDONLY | L_PTE_XN)
+#define __PAGE_SHARED __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_XN)
+#define __PAGE_SHARED_EXEC __pgprot(_L_PTE_DEFAULT | L_PTE_USER)
+#define __PAGE_COPY __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
+#define __PAGE_COPY_EXEC __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY)
+#define __PAGE_READONLY __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY | L_PTE_XN)
+#define __PAGE_READONLY_EXEC __pgprot(_L_PTE_DEFAULT | L_PTE_USER | L_PTE_RDONLY)
+
+#define __pgprot_modify(prot,mask,bits) \
+ __pgprot((pgprot_val(prot) & ~(mask)) | (bits))
+
+#define pgprot_noncached(prot) \
+ __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED)
+
+#define pgprot_writecombine(prot) \
+ __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE)
+
+#ifdef CONFIG_ARM_DMA_MEM_BUFFERABLE
+#define pgprot_dmacoherent(prot) \
+ __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_BUFFERABLE | L_PTE_XN)
+#define __HAVE_PHYS_MEM_ACCESS_PROT
+struct file;
+extern pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
+ unsigned long size, pgprot_t vma_prot);
+#else
+#define pgprot_dmacoherent(prot) \
+ __pgprot_modify(prot, L_PTE_MT_MASK, L_PTE_MT_UNCACHED | L_PTE_XN)
+#endif
+
+#endif /* __ASSEMBLY__ */
+
+/*
+ * The table below defines the page protection levels that we insert into our
+ * Linux page table version. These get translated into the best that the
+ * architecture can perform. Note that on most ARM hardware:
+ * 1) We cannot do execute protection
+ * 2) If we could do execute protection, then read is implied
+ * 3) write implies read permissions
+ */
+#define __P000 __PAGE_NONE
+#define __P001 __PAGE_READONLY
+#define __P010 __PAGE_COPY
+#define __P011 __PAGE_COPY
+#define __P100 __PAGE_READONLY_EXEC
+#define __P101 __PAGE_READONLY_EXEC
+#define __P110 __PAGE_COPY_EXEC
+#define __P111 __PAGE_COPY_EXEC
+
+#define __S000 __PAGE_NONE
+#define __S001 __PAGE_READONLY
+#define __S010 __PAGE_SHARED
+#define __S011 __PAGE_SHARED
+#define __S100 __PAGE_READONLY_EXEC
+#define __S101 __PAGE_READONLY_EXEC
+#define __S110 __PAGE_SHARED_EXEC
+#define __S111 __PAGE_SHARED_EXEC
+
+#ifndef __ASSEMBLY__
+/*
+ * ZERO_PAGE is a global shared page that is always zero: used
+ * for zero-mapped memory areas etc..
+ */
+extern struct page *empty_zero_page;
+#define ZERO_PAGE(vaddr) (empty_zero_page)
+
+
+extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
+
+/* to find an entry in a page-table-directory */
+#define pgd_index(addr) ((addr) >> PGDIR_SHIFT)
+
+#define pgd_offset(mm, addr) ((mm)->pgd + pgd_index(addr))
+
+/* to find an entry in a kernel page-table-directory */
+#define pgd_offset_k(addr) pgd_offset(&init_mm, addr)
+
+/*
+ * The "pgd_xxx()" functions here are trivial for a folded two-level
+ * setup: the pgd is never bad, and a pmd always exists (as it's folded
+ * into the pgd entry)
+ */
+#define pgd_none(pgd) (0)
+#define pgd_bad(pgd) (0)
+#define pgd_present(pgd) (1)
+#define pgd_clear(pgdp) do { } while (0)
+#define set_pgd(pgd,pgdp) do { } while (0)
+#define set_pud(pud,pudp) do { } while (0)
+
+
+/* Find an entry in the second-level page table.. */
+#define pmd_offset(dir, addr) ((pmd_t *)(dir))
+
+#define pmd_none(pmd) (!pmd_val(pmd))
+#define pmd_present(pmd) (pmd_val(pmd))
+#define pmd_bad(pmd) (pmd_val(pmd) & 2)
+
+#define copy_pmd(pmdpd,pmdps) \
+ do { \
+ pmdpd[0] = pmdps[0]; \
+ pmdpd[1] = pmdps[1]; \
+ flush_pmd_entry(pmdpd); \
+ } while (0)
+
+#define pmd_clear(pmdp) \
+ do { \
+ pmdp[0] = __pmd(0); \
+ pmdp[1] = __pmd(0); \
+ clean_pmd_entry(pmdp); \
+ } while (0)
+
+static inline pte_t *pmd_page_vaddr(pmd_t pmd)
+{
+ return __va(pmd_val(pmd) & PAGE_MASK);
+}
+
+#define pmd_page(pmd) pfn_to_page(__phys_to_pfn(pmd_val(pmd)))
+
+/* we don't need complex calculations here as the pmd is folded into the pgd */
+#define pmd_addr_end(addr,end) (end)
+
+
+#ifndef CONFIG_HIGHPTE
+#define __pte_map(pmd) pmd_page_vaddr(*(pmd))
+#define __pte_unmap(pte) do { } while (0)
+#else
+#define __pte_map(pmd) (pte_t *)kmap_atomic(pmd_page(*(pmd)))
+#define __pte_unmap(pte) kunmap_atomic(pte)
+#endif
+
+#define pte_index(addr) (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
+
+#define pte_offset_kernel(pmd,addr) (pmd_page_vaddr(*(pmd)) + pte_index(addr))
+
+#define pte_offset_map(pmd,addr) (__pte_map(pmd) + pte_index(addr))
+#define pte_unmap(pte) __pte_unmap(pte)
+
+#define pte_pfn(pte) (pte_val(pte) >> PAGE_SHIFT)
+#define pfn_pte(pfn,prot) __pte(__pfn_to_phys(pfn) | pgprot_val(prot))
+
+#define pte_page(pte) pfn_to_page(pte_pfn(pte))
+#define mk_pte(page,prot) pfn_pte(page_to_pfn(page), prot)
+
+#define set_pte_ext(ptep,pte,ext) cpu_set_pte_ext(ptep,pte,ext)
+#define pte_clear(mm,addr,ptep) set_pte_ext(ptep, __pte(0), 0)
+
+#if __LINUX_ARM_ARCH__ < 6
+static inline void __sync_icache_dcache(pte_t pteval)
+{
+}
+#else
+extern void __sync_icache_dcache(pte_t pteval);
+#endif
+
+static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
+ pte_t *ptep, pte_t pteval)
+{
+ if (addr >= TASK_SIZE)
+ set_pte_ext(ptep, pteval, 0);
+ else {
+ __sync_icache_dcache(pteval);
+ set_pte_ext(ptep, pteval, PTE_EXT_NG);
+ }
+}
+
+#define pte_none(pte) (!pte_val(pte))
+#define pte_present(pte) (pte_val(pte) & L_PTE_PRESENT)
+#define pte_write(pte) (!(pte_val(pte) & L_PTE_RDONLY))
+#define pte_dirty(pte) (pte_val(pte) & L_PTE_DIRTY)
+#define pte_young(pte) (pte_val(pte) & L_PTE_YOUNG)
+#define pte_exec(pte) (!(pte_val(pte) & L_PTE_XN))
+#define pte_special(pte) (0)
+
+#define pte_present_user(pte) \
+ ((pte_val(pte) & (L_PTE_PRESENT | L_PTE_USER)) == \
+ (L_PTE_PRESENT | L_PTE_USER))
+
+#define PTE_BIT_FUNC(fn,op) \
+static inline pte_t pte_##fn(pte_t pte) { pte_val(pte) op; return pte; }
+
+PTE_BIT_FUNC(wrprotect, |= L_PTE_RDONLY);
+PTE_BIT_FUNC(mkwrite, &= ~L_PTE_RDONLY);
+PTE_BIT_FUNC(mkclean, &= ~L_PTE_DIRTY);
+PTE_BIT_FUNC(mkdirty, |= L_PTE_DIRTY);
+PTE_BIT_FUNC(mkold, &= ~L_PTE_YOUNG);
+PTE_BIT_FUNC(mkyoung, |= L_PTE_YOUNG);
+
+static inline pte_t pte_mkspecial(pte_t pte) { return pte; }
+
+static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
+{
+ const pteval_t mask = L_PTE_XN | L_PTE_RDONLY | L_PTE_USER;
+ pte_val(pte) = (pte_val(pte) & ~mask) | (pgprot_val(newprot) & mask);
+ return pte;
+}
+
+/*
+ * Encode and decode a swap entry. Swap entries are stored in the Linux
+ * page tables as follows:
+ *
+ * 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
+ * 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
+ * <--------------- offset --------------------> <- type --> 0 0 0
+ *
+ * This gives us up to 63 swap files and 32GB per swap file. Note that
+ * the offset field is always non-zero.
+ */
+#define __SWP_TYPE_SHIFT 3
+#define __SWP_TYPE_BITS 6
+#define __SWP_TYPE_MASK ((1 << __SWP_TYPE_BITS) - 1)
+#define __SWP_OFFSET_SHIFT (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
+
+#define __swp_type(x) (((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
+#define __swp_offset(x) ((x).val >> __SWP_OFFSET_SHIFT)
+#define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })
+
+#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
+#define __swp_entry_to_pte(swp) ((pte_t) { (swp).val })
+
+/*
+ * It is an error for the kernel to have more swap files than we can
+ * encode in the PTEs. This ensures that we know when MAX_SWAPFILES
+ * is increased beyond what we presently support.
+ */
+#define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
+
+/*
+ * Encode and decode a file entry. File entries are stored in the Linux
+ * page tables as follows:
+ *
+ * 3 3 2 2 2 2 2 2 2 2 2 2 1 1 1 1 1 1 1 1 1 1
+ * 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0 9 8 7 6 5 4 3 2 1 0
+ * <----------------------- offset ------------------------> 1 0 0
+ */
+#define pte_file(pte) (pte_val(pte) & L_PTE_FILE)
+#define pte_to_pgoff(x) (pte_val(x) >> 3)
+#define pgoff_to_pte(x) __pte(((x) << 3) | L_PTE_FILE)
+
+#define PTE_FILE_MAX_BITS 29
+
+/* Needs to be defined here and not in linux/mm.h, as it is arch dependent */
+/* FIXME: this is not correct */
+#define kern_addr_valid(addr) (1)
+
+#include <asm-generic/pgtable.h>
+
+/*
+ * We provide our own arch_get_unmapped_area to cope with VIPT caches.
+ */
+#define HAVE_ARCH_UNMAPPED_AREA
+
+/*
+ * 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)
+
+#define pgtable_cache_init() do { } while (0)
+
+void identity_mapping_add(pgd_t *, unsigned long, unsigned long);
+void identity_mapping_del(pgd_t *, unsigned long, unsigned long);
+
+#endif /* !__ASSEMBLY__ */
+
+#endif /* CONFIG_MMU */
+
+#endif /* _ASMARM_PGTABLE_H */
projects / ms2-kexec / blobdiff