From 61e85e367535a7b6385b404bef93928768140f96 Mon Sep 17 00:00:00 2001 From: Jonas Bonn Date: Sat, 4 Jun 2011 11:06:11 +0300 Subject: OpenRISC: Memory management Signed-off-by: Jonas Bonn Reviewed-by: Arnd Bergmann diff --git a/arch/openrisc/include/asm/cache.h b/arch/openrisc/include/asm/cache.h new file mode 100644 index 0000000..4ce7a01 --- /dev/null +++ b/arch/openrisc/include/asm/cache.h @@ -0,0 +1,29 @@ +/* + * OpenRISC Linux + * + * Linux architectural port borrowing liberally from similar works of + * others. All original copyrights apply as per the original source + * declaration. + * + * OpenRISC implementation: + * Copyright (C) 2003 Matjaz Breskvar + * Copyright (C) 2010-2011 Jonas Bonn + * et al. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#ifndef __ASM_OPENRISC_CACHE_H +#define __ASM_OPENRISC_CACHE_H + +/* FIXME: How can we replace these with values from the CPU... + * they shouldn't be hard-coded! + */ + +#define L1_CACHE_BYTES 16 +#define L1_CACHE_SHIFT 4 + +#endif /* __ASM_OPENRISC_CACHE_H */ diff --git a/arch/openrisc/include/asm/fixmap.h b/arch/openrisc/include/asm/fixmap.h new file mode 100644 index 0000000..5273341 --- /dev/null +++ b/arch/openrisc/include/asm/fixmap.h @@ -0,0 +1,87 @@ +/* + * OpenRISC Linux + * + * Linux architectural port borrowing liberally from similar works of + * others. All original copyrights apply as per the original source + * declaration. + * + * OpenRISC implementation: + * Copyright (C) 2003 Matjaz Breskvar + * Copyright (C) 2010-2011 Jonas Bonn + * et al. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#ifndef __ASM_OPENRISC_FIXMAP_H +#define __ASM_OPENRISC_FIXMAP_H + +/* Why exactly do we need 2 empty pages between the top of the fixed + * addresses and the top of virtual memory? Something is using that + * memory space but not sure what right now... If you find it, leave + * a comment here. + */ +#define FIXADDR_TOP ((unsigned long) (-2*PAGE_SIZE)) + +#include +#include + +/* + * On OpenRISC we use these special fixed_addresses for doing ioremap + * early in the boot process before memory initialization is complete. + * This is used, in particular, by the early serial console code. + * + * It's not really 'fixmap', per se, but fits loosely into the same + * paradigm. + */ +enum fixed_addresses { + /* + * FIX_IOREMAP entries are useful for mapping physical address + * space before ioremap() is useable, e.g. really early in boot + * before kmalloc() is working. + */ +#define FIX_N_IOREMAPS 32 + FIX_IOREMAP_BEGIN, + FIX_IOREMAP_END = FIX_IOREMAP_BEGIN + FIX_N_IOREMAPS - 1, + __end_of_fixed_addresses +}; + +#define FIXADDR_SIZE (__end_of_fixed_addresses << PAGE_SHIFT) +/* FIXADDR_BOTTOM might be a better name here... */ +#define FIXADDR_START (FIXADDR_TOP - FIXADDR_SIZE) + +#define __fix_to_virt(x) (FIXADDR_TOP - ((x) << PAGE_SHIFT)) +#define __virt_to_fix(x) ((FIXADDR_TOP - ((x)&PAGE_MASK)) >> PAGE_SHIFT) + +/* + * 'index to address' translation. If anyone tries to use the idx + * directly without tranlation, we catch the bug with a NULL-deference + * kernel oops. Illegal ranges of incoming indices are caught too. + */ +static __always_inline unsigned long fix_to_virt(const unsigned int idx) +{ + /* + * this branch gets completely eliminated after inlining, + * except when someone tries to use fixaddr indices in an + * illegal way. (such as mixing up address types or using + * out-of-range indices). + * + * If it doesn't get removed, the linker will complain + * loudly with a reasonably clear error message.. + */ + if (idx >= __end_of_fixed_addresses) + BUG(); + + return __fix_to_virt(idx); +} + +static inline unsigned long virt_to_fix(const unsigned long vaddr) +{ + BUG_ON(vaddr >= FIXADDR_TOP || vaddr < FIXADDR_START); + return __virt_to_fix(vaddr); +} + +#endif diff --git a/arch/openrisc/include/asm/memblock.h b/arch/openrisc/include/asm/memblock.h new file mode 100644 index 0000000..bbe5a1c --- /dev/null +++ b/arch/openrisc/include/asm/memblock.h @@ -0,0 +1,24 @@ +/* + * OpenRISC Linux + * + * Linux architectural port borrowing liberally from similar works of + * others. All original copyrights apply as per the original source + * declaration. + * + * OpenRISC implementation: + * Copyright (C) 2003 Matjaz Breskvar + * Copyright (C) 2010-2011 Jonas Bonn + * et al. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#ifndef __ASM_OPENRISC_MEMBLOCK_H +#define __ASM_OPENRISC_MEMBLOCK_H + +/* empty */ + +#endif /* __ASM_OPENRISC_MEMBLOCK_H */ diff --git a/arch/openrisc/include/asm/mmu.h b/arch/openrisc/include/asm/mmu.h new file mode 100644 index 0000000..d069bc2 --- /dev/null +++ b/arch/openrisc/include/asm/mmu.h @@ -0,0 +1,26 @@ +/* + * OpenRISC Linux + * + * Linux architectural port borrowing liberally from similar works of + * others. All original copyrights apply as per the original source + * declaration. + * + * OpenRISC implementation: + * Copyright (C) 2003 Matjaz Breskvar + * Copyright (C) 2010-2011 Jonas Bonn + * et al. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#ifndef __ASM_OPENRISC_MMU_H +#define __ASM_OPENRISC_MMU_H + +#ifndef __ASSEMBLY__ +typedef unsigned long mm_context_t; +#endif + +#endif diff --git a/arch/openrisc/include/asm/mmu_context.h b/arch/openrisc/include/asm/mmu_context.h new file mode 100644 index 0000000..e94b814 --- /dev/null +++ b/arch/openrisc/include/asm/mmu_context.h @@ -0,0 +1,43 @@ +/* + * OpenRISC Linux + * + * Linux architectural port borrowing liberally from similar works of + * others. All original copyrights apply as per the original source + * declaration. + * + * OpenRISC implementation: + * Copyright (C) 2003 Matjaz Breskvar + * Copyright (C) 2010-2011 Jonas Bonn + * et al. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#ifndef __ASM_OPENRISC_MMU_CONTEXT_H +#define __ASM_OPENRISC_MMU_CONTEXT_H + +#include + +extern int init_new_context(struct task_struct *tsk, struct mm_struct *mm); +extern void destroy_context(struct mm_struct *mm); +extern void switch_mm(struct mm_struct *prev, struct mm_struct *next, + struct task_struct *tsk); + +#define deactivate_mm(tsk, mm) do { } while (0) + +#define activate_mm(prev, next) switch_mm((prev), (next), NULL) + +/* current active pgd - this is similar to other processors pgd + * registers like cr3 on the i386 + */ + +extern volatile pgd_t *current_pgd; /* defined in arch/openrisc/mm/fault.c */ + +static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk) +{ +} + +#endif diff --git a/arch/openrisc/include/asm/page.h b/arch/openrisc/include/asm/page.h new file mode 100644 index 0000000..b041b34 --- /dev/null +++ b/arch/openrisc/include/asm/page.h @@ -0,0 +1,110 @@ +/* + * OpenRISC Linux + * + * Linux architectural port borrowing liberally from similar works of + * others. All original copyrights apply as per the original source + * declaration. + * + * OpenRISC implementation: + * Copyright (C) 2003 Matjaz Breskvar + * Copyright (C) 2010-2011 Jonas Bonn + * et al. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#ifndef __ASM_OPENRISC_PAGE_H +#define __ASM_OPENRISC_PAGE_H + + +/* PAGE_SHIFT determines the page size */ + +#define PAGE_SHIFT 13 +#ifdef __ASSEMBLY__ +#define PAGE_SIZE (1 << PAGE_SHIFT) +#else +#define PAGE_SIZE (1UL << PAGE_SHIFT) +#endif +#define PAGE_MASK (~(PAGE_SIZE-1)) + +#define PAGE_OFFSET 0xc0000000 +#define KERNELBASE PAGE_OFFSET + +/* This is not necessarily the right place for this, but it's needed by + * drivers/of/fdt.c + */ +#include + +#ifndef __ASSEMBLY__ + +#define get_user_page(vaddr) __get_free_page(GFP_KERNEL) +#define free_user_page(page, addr) free_page(addr) + +#define clear_page(page) memset((page), 0, PAGE_SIZE) +#define copy_page(to, from) memcpy((to), (from), PAGE_SIZE) + +#define clear_user_page(page, vaddr, pg) clear_page(page) +#define copy_user_page(to, from, vaddr, pg) copy_page(to, from) + +/* + * These are used to make use of C type-checking.. + */ +typedef struct { + unsigned long pte; +} pte_t; +typedef struct { + unsigned long pgd; +} pgd_t; +typedef struct { + unsigned long pgprot; +} pgprot_t; +typedef struct page *pgtable_t; + +#define pte_val(x) ((x).pte) +#define pgd_val(x) ((x).pgd) +#define pgprot_val(x) ((x).pgprot) + +#define __pte(x) ((pte_t) { (x) }) +#define __pgd(x) ((pgd_t) { (x) }) +#define __pgprot(x) ((pgprot_t) { (x) }) + +extern unsigned long memory_start; +extern unsigned long memory_end; + +#endif /* !__ASSEMBLY__ */ + + +#ifndef __ASSEMBLY__ + +#define __va(x) ((void *)((unsigned long)(x) + PAGE_OFFSET)) +#define __pa(x) ((unsigned long) (x) - PAGE_OFFSET) + +#define virt_to_pfn(kaddr) (__pa(kaddr) >> PAGE_SHIFT) +#define pfn_to_virt(pfn) __va((pfn) << PAGE_SHIFT) + +#define virt_to_page(addr) \ + (mem_map + (((unsigned long)(addr)-PAGE_OFFSET) >> PAGE_SHIFT)) +#define page_to_virt(page) \ + ((((page) - mem_map) << PAGE_SHIFT) + PAGE_OFFSET) + +#define page_to_phys(page) ((dma_addr_t)page_to_pfn(page) << PAGE_SHIFT) + +#define pfn_valid(pfn) ((pfn) < max_mapnr) + +#define virt_addr_valid(kaddr) (((void *)(kaddr) >= (void *)PAGE_OFFSET) && \ + ((void *)(kaddr) < (void *)memory_end)) + +#endif /* __ASSEMBLY__ */ + + +#define VM_DATA_DEFAULT_FLAGS (VM_READ | VM_WRITE | VM_EXEC | \ + VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC) + + +#include +#include + +#endif /* __ASM_OPENRISC_PAGE_H */ diff --git a/arch/openrisc/include/asm/pgalloc.h b/arch/openrisc/include/asm/pgalloc.h new file mode 100644 index 0000000..05c39ec --- /dev/null +++ b/arch/openrisc/include/asm/pgalloc.h @@ -0,0 +1,102 @@ +/* + * OpenRISC Linux + * + * Linux architectural port borrowing liberally from similar works of + * others. All original copyrights apply as per the original source + * declaration. + * + * OpenRISC implementation: + * Copyright (C) 2003 Matjaz Breskvar + * Copyright (C) 2010-2011 Jonas Bonn + * et al. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#ifndef __ASM_OPENRISC_PGALLOC_H +#define __ASM_OPENRISC_PGALLOC_H + +#include +#include +#include +#include +#include + +extern int mem_init_done; + +#define pmd_populate_kernel(mm, pmd, pte) \ + set_pmd(pmd, __pmd(_KERNPG_TABLE + __pa(pte))) + +static inline void pmd_populate(struct mm_struct *mm, pmd_t *pmd, + struct page *pte) +{ + set_pmd(pmd, __pmd(_KERNPG_TABLE + + ((unsigned long)page_to_pfn(pte) << + (unsigned long) PAGE_SHIFT))); +} + +/* + * Allocate and free page tables. + */ +static inline pgd_t *pgd_alloc(struct mm_struct *mm) +{ + pgd_t *ret = (pgd_t *)__get_free_page(GFP_KERNEL); + + if (ret) { + memset(ret, 0, USER_PTRS_PER_PGD * sizeof(pgd_t)); + memcpy(ret + USER_PTRS_PER_PGD, + swapper_pg_dir + USER_PTRS_PER_PGD, + (PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t)); + + } + return ret; +} + +#if 0 +/* FIXME: This seems to be the preferred style, but we are using + * current_pgd (from mm->pgd) to load kernel pages so we need it + * initialized. This needs to be looked into. + */ +extern inline pgd_t *pgd_alloc(struct mm_struct *mm) +{ + return (pgd_t *)get_zeroed_page(GFP_KERNEL); +} +#endif + +static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd) +{ + free_page((unsigned long)pgd); +} + +extern pte_t *pte_alloc_one_kernel(struct mm_struct *mm, unsigned long address); + +static inline struct page *pte_alloc_one(struct mm_struct *mm, + unsigned long address) +{ + struct page *pte; + pte = alloc_pages(GFP_KERNEL|__GFP_REPEAT, 0); + if (pte) + clear_page(page_address(pte)); + return pte; +} + +static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte) +{ + free_page((unsigned long)pte); +} + +static inline void pte_free(struct mm_struct *mm, struct page *pte) +{ + __free_page(pte); +} + + +#define __pte_free_tlb(tlb, pte, addr) tlb_remove_page((tlb), (pte)) +#define pmd_pgtable(pmd) pmd_page(pmd) + +#define check_pgt_cache() do { } while (0) + +#endif diff --git a/arch/openrisc/include/asm/pgtable.h b/arch/openrisc/include/asm/pgtable.h new file mode 100644 index 0000000..043505d --- /dev/null +++ b/arch/openrisc/include/asm/pgtable.h @@ -0,0 +1,463 @@ +/* + * OpenRISC Linux + * + * Linux architectural port borrowing liberally from similar works of + * others. All original copyrights apply as per the original source + * declaration. + * + * OpenRISC implementation: + * Copyright (C) 2003 Matjaz Breskvar + * Copyright (C) 2010-2011 Jonas Bonn + * et al. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +/* or32 pgtable.h - macros and functions to manipulate page tables + * + * Based on: + * include/asm-cris/pgtable.h + */ + +#ifndef __ASM_OPENRISC_PGTABLE_H +#define __ASM_OPENRISC_PGTABLE_H + +#include + +#ifndef __ASSEMBLY__ +#include +#include + +/* + * The Linux memory management assumes a three-level page table setup. On + * or32, we use that, but "fold" the mid level into the top-level page + * table. Since the MMU TLB is software loaded through an interrupt, it + * supports any page table structure, so we could have used a three-level + * setup, but for the amounts of memory we normally use, a two-level is + * probably more efficient. + * + * This file contains the functions and defines necessary to modify and use + * the or32 page table tree. + */ + +extern void paging_init(void); + +/* 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) +/* + * (pmds are folded into pgds so this doesn't get actually called, + * but the define is needed for a generic inline function.) + */ +#define set_pmd(pmdptr, pmdval) (*(pmdptr) = pmdval) + +#define PGDIR_SHIFT (PAGE_SHIFT + (PAGE_SHIFT-2)) +#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. + * pointers are 4 bytes so we can use the page size and + * divide it by 4 (shift by 2). + */ +#define PTRS_PER_PTE (1UL << (PAGE_SHIFT-2)) + +#define PTRS_PER_PGD (1UL << (PAGE_SHIFT-2)) + +/* calculate how many PGD entries a user-level program can use + * the first mappable virtual address is 0 + * (TASK_SIZE is the maximum virtual address space) + */ + +#define USER_PTRS_PER_PGD (TASK_SIZE/PGDIR_SIZE) +#define FIRST_USER_ADDRESS 0 + +/* + * Kernels own virtual memory area. + */ + +/* + * The size and location of the vmalloc area are chosen so that modules + * placed in this area aren't more than a 28-bit signed offset from any + * kernel functions that they may need. This greatly simplifies handling + * of the relocations for l.j and l.jal instructions as we don't need to + * introduce any trampolines for reaching "distant" code. + * + * 64 MB of vmalloc area is comparable to what's available on other arches. + */ + +#define VMALLOC_START (PAGE_OFFSET-0x04000000) +#define VMALLOC_END (PAGE_OFFSET) +#define VMALLOC_VMADDR(x) ((unsigned long)(x)) + +/* Define some higher level generic page attributes. + * + * If you change _PAGE_CI definition be sure to change it in + * io.h for ioremap_nocache() too. + */ + +/* + * An OR32 PTE looks like this: + * + * | 31 ... 10 | 9 | 8 ... 6 | 5 | 4 | 3 | 2 | 1 | 0 | + * Phys pg.num L PP Index D A WOM WBC CI CC + * + * L : link + * PPI: Page protection index + * D : Dirty + * A : Accessed + * WOM: Weakly ordered memory + * WBC: Write-back cache + * CI : Cache inhibit + * CC : Cache coherent + * + * The protection bits below should correspond to the layout of the actual + * PTE as per above + */ + +#define _PAGE_CC 0x001 /* software: pte contains a translation */ +#define _PAGE_CI 0x002 /* cache inhibit */ +#define _PAGE_WBC 0x004 /* write back cache */ +#define _PAGE_FILE 0x004 /* set: pagecache, unset: swap (when !PRESENT) */ +#define _PAGE_WOM 0x008 /* weakly ordered memory */ + +#define _PAGE_A 0x010 /* accessed */ +#define _PAGE_D 0x020 /* dirty */ +#define _PAGE_URE 0x040 /* user read enable */ +#define _PAGE_UWE 0x080 /* user write enable */ + +#define _PAGE_SRE 0x100 /* superuser read enable */ +#define _PAGE_SWE 0x200 /* superuser write enable */ +#define _PAGE_EXEC 0x400 /* software: page is executable */ +#define _PAGE_U_SHARED 0x800 /* software: page is shared in user space */ + +/* 0x001 is cache coherency bit, which should always be set to + * 1 - for SMP (when we support it) + * 0 - otherwise + * + * we just reuse this bit in software for _PAGE_PRESENT and + * force it to 0 when loading it into TLB. + */ +#define _PAGE_PRESENT _PAGE_CC +#define _PAGE_USER _PAGE_URE +#define _PAGE_WRITE (_PAGE_UWE | _PAGE_SWE) +#define _PAGE_DIRTY _PAGE_D +#define _PAGE_ACCESSED _PAGE_A +#define _PAGE_NO_CACHE _PAGE_CI +#define _PAGE_SHARED _PAGE_U_SHARED +#define _PAGE_READ (_PAGE_URE | _PAGE_SRE) + +#define _PAGE_CHG_MASK (PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY) +#define _PAGE_BASE (_PAGE_PRESENT | _PAGE_ACCESSED) +#define _PAGE_ALL (_PAGE_PRESENT | _PAGE_ACCESSED) +#define _KERNPG_TABLE \ + (_PAGE_BASE | _PAGE_SRE | _PAGE_SWE | _PAGE_ACCESSED | _PAGE_DIRTY) + +#define PAGE_NONE __pgprot(_PAGE_ALL) +#define PAGE_READONLY __pgprot(_PAGE_ALL | _PAGE_URE | _PAGE_SRE) +#define PAGE_READONLY_X __pgprot(_PAGE_ALL | _PAGE_URE | _PAGE_SRE | _PAGE_EXEC) +#define PAGE_SHARED \ + __pgprot(_PAGE_ALL | _PAGE_URE | _PAGE_SRE | _PAGE_UWE | _PAGE_SWE \ + | _PAGE_SHARED) +#define PAGE_SHARED_X \ + __pgprot(_PAGE_ALL | _PAGE_URE | _PAGE_SRE | _PAGE_UWE | _PAGE_SWE \ + | _PAGE_SHARED | _PAGE_EXEC) +#define PAGE_COPY __pgprot(_PAGE_ALL | _PAGE_URE | _PAGE_SRE) +#define PAGE_COPY_X __pgprot(_PAGE_ALL | _PAGE_URE | _PAGE_SRE | _PAGE_EXEC) + +#define PAGE_KERNEL \ + __pgprot(_PAGE_ALL | _PAGE_SRE | _PAGE_SWE \ + | _PAGE_SHARED | _PAGE_DIRTY | _PAGE_EXEC) +#define PAGE_KERNEL_RO \ + __pgprot(_PAGE_ALL | _PAGE_SRE \ + | _PAGE_SHARED | _PAGE_DIRTY | _PAGE_EXEC) +#define PAGE_KERNEL_NOCACHE \ + __pgprot(_PAGE_ALL | _PAGE_SRE | _PAGE_SWE \ + | _PAGE_SHARED | _PAGE_DIRTY | _PAGE_EXEC | _PAGE_CI) + +#define __P000 PAGE_NONE +#define __P001 PAGE_READONLY_X +#define __P010 PAGE_COPY +#define __P011 PAGE_COPY_X +#define __P100 PAGE_READONLY +#define __P101 PAGE_READONLY_X +#define __P110 PAGE_COPY +#define __P111 PAGE_COPY_X + +#define __S000 PAGE_NONE +#define __S001 PAGE_READONLY_X +#define __S010 PAGE_SHARED +#define __S011 PAGE_SHARED_X +#define __S100 PAGE_READONLY +#define __S101 PAGE_READONLY_X +#define __S110 PAGE_SHARED +#define __S111 PAGE_SHARED_X + +/* zero page used for uninitialized stuff */ +extern unsigned long empty_zero_page[2048]; +#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page)) + +/* number of bits that fit into a memory pointer */ +#define BITS_PER_PTR (8*sizeof(unsigned long)) + +/* to align the pointer to a pointer address */ +#define PTR_MASK (~(sizeof(void *)-1)) + +/* sizeof(void*)==1<>(PAGE_SHIFT-SIZEOF_PTR_LOG2)&PTR_MASK&~PAGE_MASK) + +/* to set the page-dir */ +#define SET_PAGE_DIR(tsk, pgdir) + +#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)) != _KERNPG_TABLE) +#define pmd_present(x) (pmd_val(x) & _PAGE_PRESENT) +#define pmd_clear(xp) do { pmd_val(*(xp)) = 0; } while (0) + +/* + * The following only work if pte_present() is true. + * Undefined behaviour if not.. + */ + +static inline int pte_read(pte_t pte) { return pte_val(pte) & _PAGE_READ; } +static inline int pte_write(pte_t pte) { return pte_val(pte) & _PAGE_WRITE; } +static inline int pte_exec(pte_t pte) { return pte_val(pte) & _PAGE_EXEC; } +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_mkspecial(pte_t pte) { return pte; } + +static inline pte_t pte_wrprotect(pte_t pte) +{ + pte_val(pte) &= ~(_PAGE_WRITE); + return pte; +} + +static inline pte_t pte_rdprotect(pte_t pte) +{ + pte_val(pte) &= ~(_PAGE_READ); + return pte; +} + +static inline pte_t pte_exprotect(pte_t pte) +{ + pte_val(pte) &= ~(_PAGE_EXEC); + 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_mkread(pte_t pte) +{ + pte_val(pte) |= _PAGE_READ; + return pte; +} + +static inline pte_t pte_mkexec(pte_t pte) +{ + pte_val(pte) |= _PAGE_EXEC; + 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; +} + +/* + * Conversion functions: convert a page and protection to a page entry, + * and a page entry and page directory to the page they refer to. + */ + +/* What actually goes as arguments to the various functions is less than + * obvious, but a rule of thumb is that struct page's goes as struct page *, + * really physical DRAM addresses are unsigned long's, and DRAM "virtual" + * addresses (the 0xc0xxxxxx's) goes as void *'s. + */ + +static inline pte_t __mk_pte(void *page, pgprot_t pgprot) +{ + pte_t pte; + /* the PTE needs a physical address */ + pte_val(pte) = __pa(page) | pgprot_val(pgprot); + return pte; +} + +#define mk_pte(page, pgprot) __mk_pte(page_address(page), (pgprot)) + +#define mk_pte_phys(physpage, pgprot) \ +({ \ + pte_t __pte; \ + \ + pte_val(__pte) = (physpage) + pgprot_val(pgprot); \ + __pte; \ +}) + +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; +} + + +/* + * pte_val refers to a page in the 0x0xxxxxxx physical DRAM interval + * __pte_page(pte_val) refers to the "virtual" DRAM interval + * pte_pagenr refers to the page-number counted starting from the virtual + * DRAM start + */ + +static inline unsigned long __pte_page(pte_t pte) +{ + /* the PTE contains a physical address */ + return (unsigned long)__va(pte_val(pte) & PAGE_MASK); +} + +#define pte_pagenr(pte) ((__pte_page(pte) - PAGE_OFFSET) >> PAGE_SHIFT) + +/* permanent address of a page */ + +#define __page_address(page) (PAGE_OFFSET + (((page) - mem_map) << PAGE_SHIFT)) +#define pte_page(pte) (mem_map+pte_pagenr(pte)) + +/* + * only the pte's themselves need to point to physical DRAM (see above) + * the pagetable links are purely handled within the kernel SW and thus + * don't need the __pa and __va transformations. + */ +static inline void pmd_set(pmd_t *pmdp, pte_t *ptep) +{ + pmd_val(*pmdp) = _KERNPG_TABLE | (unsigned long) ptep; +} + +#define pmd_page(pmd) (pfn_to_page(pmd_val(pmd) >> PAGE_SHIFT)) +#define pmd_page_kernel(pmd) ((unsigned long) __va(pmd_val(pmd) & PAGE_MASK)) + +/* to find an entry in a page-table-directory. */ +#define pgd_index(address) ((address >> PGDIR_SHIFT) & (PTRS_PER_PGD-1)) + +#define __pgd_offset(address) pgd_index(address) + +#define pgd_offset(mm, address) ((mm)->pgd+pgd_index(address)) + +/* to find an entry in a kernel page-table-directory */ +#define pgd_offset_k(address) pgd_offset(&init_mm, address) + +#define __pmd_offset(address) \ + (((address) >> PMD_SHIFT) & (PTRS_PER_PMD-1)) + +/* + * the pte page can be thought of an array like this: pte_t[PTRS_PER_PTE] + * + * this macro returns the index of the entry in the pte page which would + * control the given virtual address + */ +#define __pte_offset(address) \ + (((address) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1)) +#define pte_offset_kernel(dir, address) \ + ((pte_t *) pmd_page_kernel(*(dir)) + __pte_offset(address)) +#define pte_offset_map(dir, address) \ + ((pte_t *)page_address(pmd_page(*(dir))) + __pte_offset(address)) +#define pte_offset_map_nested(dir, address) \ + pte_offset_map(dir, address) + +#define pte_unmap(pte) do { } while (0) +#define pte_unmap_nested(pte) do { } while (0) +#define pte_pfn(x) ((unsigned long)(((x).pte)) >> PAGE_SHIFT) +#define pfn_pte(pfn, prot) __pte((((pfn) << PAGE_SHIFT)) | pgprot_val(prot)) + +#define pte_ERROR(e) \ + printk(KERN_ERR "%s:%d: bad pte %p(%08lx).\n", \ + __FILE__, __LINE__, &(e), pte_val(e)) +#define pgd_ERROR(e) \ + printk(KERN_ERR "%s:%d: bad pgd %p(%08lx).\n", \ + __FILE__, __LINE__, &(e), pgd_val(e)) + +extern pgd_t swapper_pg_dir[PTRS_PER_PGD]; /* defined in head.S */ + +/* + * or32 doesn't have any external MMU info: the kernel page + * tables contain all the necessary information. + * + * Actually I am not sure on what this could be used for. + */ +static inline void update_mmu_cache(struct vm_area_struct *vma, + unsigned long address, pte_t *pte) +{ +} + +/* __PHX__ FIXME, SWAP, this probably doesn't work */ + +/* Encode and de-code a swap entry (must be !pte_none(e) && !pte_present(e)) */ +/* Since the PAGE_PRESENT bit is bit 4, we can use the bits above */ + +#define __swp_type(x) (((x).val >> 5) & 0x7f) +#define __swp_offset(x) ((x).val >> 12) +#define __swp_entry(type, offset) \ + ((swp_entry_t) { ((type) << 5) | ((offset) << 12) }) +#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) }) +#define __swp_entry_to_pte(x) ((pte_t) { (x).val }) + +/* Encode and decode a nonlinear file mapping entry */ + +#define PTE_FILE_MAX_BITS 26 +#define pte_to_pgoff(x) (pte_val(x) >> 6) +#define pgoff_to_pte(x) __pte(((x) << 6) | _PAGE_FILE) + +#define kern_addr_valid(addr) (1) + +#define io_remap_pfn_range(vma, vaddr, pfn, size, prot) \ + remap_pfn_range(vma, vaddr, pfn, size, prot) + +#include + +/* + * No page table caches to initialise + */ +#define pgtable_cache_init() do { } while (0) +#define io_remap_page_range remap_page_range + +typedef pte_t *pte_addr_t; + +#endif /* __ASSEMBLY__ */ +#endif /* __ASM_OPENRISC_PGTABLE_H */ diff --git a/arch/openrisc/include/asm/tlb.h b/arch/openrisc/include/asm/tlb.h new file mode 100644 index 0000000..fa4376a --- /dev/null +++ b/arch/openrisc/include/asm/tlb.h @@ -0,0 +1,34 @@ +/* + * OpenRISC Linux + * + * Linux architectural port borrowing liberally from similar works of + * others. All original copyrights apply as per the original source + * declaration. + * + * OpenRISC implementation: + * Copyright (C) 2003 Matjaz Breskvar + * Copyright (C) 2010-2011 Jonas Bonn + * et al. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#ifndef __ASM_OPENRISC_TLB_H__ +#define __ASM_OPENRISC_TLB_H__ + +/* + * or32 doesn't need any special per-pte or + * per-vma handling.. + */ +#define tlb_start_vma(tlb, vma) do { } while (0) +#define tlb_end_vma(tlb, vma) do { } while (0) +#define __tlb_remove_tlb_entry(tlb, ptep, address) do { } while (0) + +#define tlb_flush(tlb) flush_tlb_mm((tlb)->mm) +#include +#include + +#endif /* __ASM_OPENRISC_TLB_H__ */ diff --git a/arch/openrisc/include/asm/tlbflush.h b/arch/openrisc/include/asm/tlbflush.h new file mode 100644 index 0000000..6a2accd --- /dev/null +++ b/arch/openrisc/include/asm/tlbflush.h @@ -0,0 +1,55 @@ +/* + * OpenRISC Linux + * + * Linux architectural port borrowing liberally from similar works of + * others. All original copyrights apply as per the original source + * declaration. + * + * OpenRISC implementation: + * Copyright (C) 2003 Matjaz Breskvar + * Copyright (C) 2010-2011 Jonas Bonn + * et al. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#ifndef __ASM_OPENRISC_TLBFLUSH_H +#define __ASM_OPENRISC_TLBFLUSH_H + +#include +#include +#include +#include +#include +#include + +/* + * - flush_tlb() flushes the current mm struct TLBs + * - flush_tlb_all() flushes all processes TLBs + * - flush_tlb_mm(mm) flushes the specified mm context TLB's + * - flush_tlb_page(vma, vmaddr) flushes one page + * - flush_tlb_range(mm, start, end) flushes a range of pages + */ + +void flush_tlb_all(void); +void flush_tlb_mm(struct mm_struct *mm); +void flush_tlb_page(struct vm_area_struct *vma, unsigned long addr); +void flush_tlb_range(struct vm_area_struct *vma, + unsigned long start, + unsigned long end); + +static inline void flush_tlb(void) +{ + flush_tlb_mm(current->mm); +} + +static inline void flush_tlb_kernel_range(unsigned long start, + unsigned long end) +{ + flush_tlb_range(NULL, start, end); +} + +#endif /* __ASM_OPENRISC_TLBFLUSH_H */ diff --git a/arch/openrisc/include/asm/uaccess.h b/arch/openrisc/include/asm/uaccess.h new file mode 100644 index 0000000..c310e45 --- /dev/null +++ b/arch/openrisc/include/asm/uaccess.h @@ -0,0 +1,355 @@ +/* + * OpenRISC Linux + * + * Linux architectural port borrowing liberally from similar works of + * others. All original copyrights apply as per the original source + * declaration. + * + * OpenRISC implementation: + * Copyright (C) 2003 Matjaz Breskvar + * Copyright (C) 2010-2011 Jonas Bonn + * et al. + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + */ + +#ifndef __ASM_OPENRISC_UACCESS_H +#define __ASM_OPENRISC_UACCESS_H + +/* + * User space memory access functions + */ +#include +#include +#include +#include +#include +#include + +#define VERIFY_READ 0 +#define VERIFY_WRITE 1 + +/* + * The fs value determines whether argument validity checking should be + * performed or not. If get_fs() == USER_DS, checking is performed, with + * get_fs() == KERNEL_DS, checking is bypassed. + * + * For historical reasons, these macros are grossly misnamed. + */ + +/* addr_limit is the maximum accessible address for the task. we misuse + * the KERNEL_DS and USER_DS values to both assign and compare the + * addr_limit values through the equally misnamed get/set_fs macros. + * (see above) + */ + +#define KERNEL_DS (~0UL) +#define get_ds() (KERNEL_DS) + +#define USER_DS (TASK_SIZE) +#define get_fs() (current_thread_info()->addr_limit) +#define set_fs(x) (current_thread_info()->addr_limit = (x)) + +#define segment_eq(a, b) ((a) == (b)) + +/* Ensure that the range from addr to addr+size is all within the process' + * address space + */ +#define __range_ok(addr, size) (size <= get_fs() && addr <= (get_fs()-size)) + +/* Ensure that addr is below task's addr_limit */ +#define __addr_ok(addr) ((unsigned long) addr < get_fs()) + +#define access_ok(type, addr, size) \ + __range_ok((unsigned long)addr, (unsigned long)size) + +/* + * The exception table consists of pairs of addresses: the first is the + * address of an instruction that is allowed to fault, and the second is + * the address at which the program should continue. No registers are + * modified, so it is entirely up to the continuation code to figure out + * what to do. + * + * All the routines below use bits of fixup code that are out of line + * with the main instruction path. This means when everything is well, + * we don't even have to jump over them. Further, they do not intrude + * on our cache or tlb entries. + */ + +struct exception_table_entry { + unsigned long insn, fixup; +}; + +/* Returns 0 if exception not found and fixup otherwise. */ +extern unsigned long search_exception_table(unsigned long); +extern void sort_exception_table(void); + +/* + * These are the main single-value transfer routines. They automatically + * use the right size if we just have the right pointer type. + * + * This gets kind of ugly. We want to return _two_ values in "get_user()" + * and yet we don't want to do any pointers, because that is too much + * of a performance impact. Thus we have a few rather ugly macros here, + * and hide all the uglyness from the user. + * + * The "__xxx" versions of the user access functions are versions that + * do not verify the address space, that must have been done previously + * with a separate "access_ok()" call (this is used when we do multiple + * accesses to the same area of user memory). + * + * As we use the same address space for kernel and user data on the + * PowerPC, we can just do these as direct assignments. (Of course, the + * exception handling means that it's no longer "just"...) + */ +#define get_user(x, ptr) \ + __get_user_check((x), (ptr), sizeof(*(ptr))) +#define put_user(x, ptr) \ + __put_user_check((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) + +#define __get_user(x, ptr) \ + __get_user_nocheck((x), (ptr), sizeof(*(ptr))) +#define __put_user(x, ptr) \ + __put_user_nocheck((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr))) + +extern long __put_user_bad(void); + +#define __put_user_nocheck(x, ptr, size) \ +({ \ + long __pu_err; \ + __put_user_size((x), (ptr), (size), __pu_err); \ + __pu_err; \ +}) + +#define __put_user_check(x, ptr, size) \ +({ \ + long __pu_err = -EFAULT; \ + __typeof__(*(ptr)) *__pu_addr = (ptr); \ + if (access_ok(VERIFY_WRITE, __pu_addr, size)) \ + __put_user_size((x), __pu_addr, (size), __pu_err); \ + __pu_err; \ +}) + +#define __put_user_size(x, ptr, size, retval) \ +do { \ + retval = 0; \ + switch (size) { \ + case 1: __put_user_asm(x, ptr, retval, "l.sb"); break; \ + case 2: __put_user_asm(x, ptr, retval, "l.sh"); break; \ + case 4: __put_user_asm(x, ptr, retval, "l.sw"); break; \ + case 8: __put_user_asm2(x, ptr, retval); break; \ + default: __put_user_bad(); \ + } \ +} while (0) + +struct __large_struct { + unsigned long buf[100]; +}; +#define __m(x) (*(struct __large_struct *)(x)) + +/* + * We don't tell gcc that we are accessing memory, but this is OK + * because we do not write to any memory gcc knows about, so there + * are no aliasing issues. + */ +#define __put_user_asm(x, addr, err, op) \ + __asm__ __volatile__( \ + "1: "op" 0(%2),%1\n" \ + "2:\n" \ + ".section .fixup,\"ax\"\n" \ + "3: l.addi %0,r0,%3\n" \ + " l.j 2b\n" \ + " l.nop\n" \ + ".previous\n" \ + ".section __ex_table,\"a\"\n" \ + " .align 2\n" \ + " .long 1b,3b\n" \ + ".previous" \ + : "=r"(err) \ + : "r"(x), "r"(addr), "i"(-EFAULT), "0"(err)) + +#define __put_user_asm2(x, addr, err) \ + __asm__ __volatile__( \ + "1: l.sw 0(%2),%1\n" \ + "2: l.sw 4(%2),%H1\n" \ + "3:\n" \ + ".section .fixup,\"ax\"\n" \ + "4: l.addi %0,r0,%3\n" \ + " l.j 3b\n" \ + " l.nop\n" \ + ".previous\n" \ + ".section __ex_table,\"a\"\n" \ + " .align 2\n" \ + " .long 1b,4b\n" \ + " .long 2b,4b\n" \ + ".previous" \ + : "=r"(err) \ + : "r"(x), "r"(addr), "i"(-EFAULT), "0"(err)) + +#define __get_user_nocheck(x, ptr, size) \ +({ \ + long __gu_err, __gu_val; \ + __get_user_size(__gu_val, (ptr), (size), __gu_err); \ + (x) = (__typeof__(*(ptr)))__gu_val; \ + __gu_err; \ +}) + +#define __get_user_check(x, ptr, size) \ +({ \ + long __gu_err = -EFAULT, __gu_val = 0; \ + const __typeof__(*(ptr)) * __gu_addr = (ptr); \ + if (access_ok(VERIFY_READ, __gu_addr, size)) \ + __get_user_size(__gu_val, __gu_addr, (size), __gu_err); \ + (x) = (__typeof__(*(ptr)))__gu_val; \ + __gu_err; \ +}) + +extern long __get_user_bad(void); + +#define __get_user_size(x, ptr, size, retval) \ +do { \ + retval = 0; \ + switch (size) { \ + case 1: __get_user_asm(x, ptr, retval, "l.lbz"); break; \ + case 2: __get_user_asm(x, ptr, retval, "l.lhz"); break; \ + case 4: __get_user_asm(x, ptr, retval, "l.lwz"); break; \ + case 8: __get_user_asm2(x, ptr, retval); \ + default: (x) = __get_user_bad(); \ + } \ +} while (0) + +#define __get_user_asm(x, addr, err, op) \ + __asm__ __volatile__( \ + "1: "op" %1,0(%2)\n" \ + "2:\n" \ + ".section .fixup,\"ax\"\n" \ + "3: l.addi %0,r0,%3\n" \ + " l.addi %1,r0,0\n" \ + " l.j 2b\n" \ + " l.nop\n" \ + ".previous\n" \ + ".section __ex_table,\"a\"\n" \ + " .align 2\n" \ + " .long 1b,3b\n" \ + ".previous" \ + : "=r"(err), "=r"(x) \ + : "r"(addr), "i"(-EFAULT), "0"(err)) + +#define __get_user_asm2(x, addr, err) \ + __asm__ __volatile__( \ + "1: l.lwz %1,0(%2)\n" \ + "2: l.lwz %H1,4(%2)\n" \ + "3:\n" \ + ".section .fixup,\"ax\"\n" \ + "4: l.addi %0,r0,%3\n" \ + " l.addi %1,r0,0\n" \ + " l.addi %H1,r0,0\n" \ + " l.j 3b\n" \ + " l.nop\n" \ + ".previous\n" \ + ".section __ex_table,\"a\"\n" \ + " .align 2\n" \ + " .long 1b,4b\n" \ + " .long 2b,4b\n" \ + ".previous" \ + : "=r"(err), "=&r"(x) \ + : "r"(addr), "i"(-EFAULT), "0"(err)) + +/* more complex routines */ + +extern unsigned long __must_check +__copy_tofrom_user(void *to, const void *from, unsigned long size); + +#define __copy_from_user(to, from, size) \ + __copy_tofrom_user(to, from, size) +#define __copy_to_user(to, from, size) \ + __copy_tofrom_user(to, from, size) + +#define __copy_to_user_inatomic __copy_to_user +#define __copy_from_user_inatomic __copy_from_user + +static inline unsigned long +copy_from_user(void *to, const void *from, unsigned long n) +{ + unsigned long over; + + if (access_ok(VERIFY_READ, from, n)) + return __copy_tofrom_user(to, from, n); + if ((unsigned long)from < TASK_SIZE) { + over = (unsigned long)from + n - TASK_SIZE; + return __copy_tofrom_user(to, from, n - over) + over; + } + return n; +} + +static inline unsigned long +copy_to_user(void *to, const void *from, unsigned long n) +{ + unsigned long over; + + if (access_ok(VERIFY_WRITE, to, n)) + return __copy_tofrom_user(to, from, n); + if ((unsigned long)to < TASK_SIZE) { + over = (unsigned long)to + n - TASK_SIZE; + return __copy_tofrom_user(to, from, n - over) + over; + } + return n; +} + +extern unsigned long __clear_user(void *addr, unsigned long size); + +static inline __must_check unsigned long +clear_user(void *addr, unsigned long size) +{ + + if (access_ok(VERIFY_WRITE, addr, size)) + return __clear_user(addr, size); + if ((unsigned long)addr < TASK_SIZE) { + unsigned long over = (unsigned long)addr + size - TASK_SIZE; + return __clear_user(addr, size - over) + over; + } + return size; +} + +extern int __strncpy_from_user(char *dst, const char *src, long count); + +static inline long strncpy_from_user(char *dst, const char *src, long count) +{ + if (access_ok(VERIFY_READ, src, 1)) + return __strncpy_from_user(dst, src, count); + return -EFAULT; +} + +/* + * Return the size of a string (including the ending 0) + * + * Return 0 for error + */ + +extern int __strnlen_user(const char *str, long len, unsigned long top); + +/* + * Returns the length of the string at str (including the null byte), + * or 0 if we hit a page we can't access, + * or something > len if we didn't find a null byte. + * + * The `top' parameter to __strnlen_user is to make sure that + * we can never overflow from the user area into kernel space. + */ +static inline long strnlen_user(const char __user *str, long len) +{ + unsigned long top = (unsigned long)get_fs(); + unsigned long res = 0; + + if (__addr_ok(str)) + res = __strnlen_user(str, len, top); + + return res; +} + +#define strlen_user(str) strnlen_user(str, TASK_SIZE-1) + +#endif /* __ASM_OPENRISC_UACCESS_H */ diff --git a/arch/openrisc/mm/fault.c b/arch/openrisc/mm/fault.c new file mode 100644 index 0000000..a5dce82 --- /dev/null +++ b/arch/openrisc/mm/fault.c @@ -0,0 +1,338 @@ +/* + * OpenRISC fault.c + * + * Linux architectural port borrowing liberally from similar works of + * others. All original copyrights apply as per the original source + * declaration. + * + * Modifications for the OpenRISC architecture: + * Copyright (C) 2003 Matjaz Breskvar + * Copyright (C) 2010-2011 Jonas Bonn + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include +#include +#include +#include + +#include +#include +#include + +#define NUM_TLB_ENTRIES 64 +#define TLB_OFFSET(add) (((add) >> PAGE_SHIFT) & (NUM_TLB_ENTRIES-1)) + +unsigned long pte_misses; /* updated by do_page_fault() */ +unsigned long pte_errors; /* updated by do_page_fault() */ + +/* __PHX__ :: - check the vmalloc_fault in do_page_fault() + * - also look into include/asm-or32/mmu_context.h + */ +volatile pgd_t *current_pgd; + +extern void die(char *, struct pt_regs *, long); + +/* + * This routine handles page faults. It determines the address, + * and the problem, and then passes it off to one of the appropriate + * routines. + * + * If this routine detects a bad access, it returns 1, otherwise it + * returns 0. + */ + +asmlinkage void do_page_fault(struct pt_regs *regs, unsigned long address, + unsigned long vector, int write_acc) +{ + struct task_struct *tsk; + struct mm_struct *mm; + struct vm_area_struct *vma; + siginfo_t info; + int fault; + + tsk = current; + + /* + * We fault-in kernel-space virtual memory on-demand. The + * 'reference' page table is init_mm.pgd. + * + * NOTE! We MUST NOT take any locks for this case. We may + * be in an interrupt or a critical region, and should + * only copy the information from the master page table, + * nothing more. + * + * NOTE2: This is done so that, when updating the vmalloc + * mappings we don't have to walk all processes pgdirs and + * add the high mappings all at once. Instead we do it as they + * are used. However vmalloc'ed page entries have the PAGE_GLOBAL + * bit set so sometimes the TLB can use a lingering entry. + * + * This verifies that the fault happens in kernel space + * and that the fault was not a protection error. + */ + + if (address >= VMALLOC_START && + (vector != 0x300 && vector != 0x400) && + !user_mode(regs)) + goto vmalloc_fault; + + /* If exceptions were enabled, we can reenable them here */ + if (user_mode(regs)) { + /* Exception was in userspace: reenable interrupts */ + local_irq_enable(); + } else { + /* If exception was in a syscall, then IRQ's may have + * been enabled or disabled. If they were enabled, + * reenable them. + */ + if (regs->sr && (SPR_SR_IEE | SPR_SR_TEE)) + local_irq_enable(); + } + + mm = tsk->mm; + info.si_code = SEGV_MAPERR; + + /* + * If we're in an interrupt or have no user + * context, we must not take the fault.. + */ + + if (in_interrupt() || !mm) + goto no_context; + + down_read(&mm->mmap_sem); + vma = find_vma(mm, address); + + if (!vma) + goto bad_area; + + if (vma->vm_start <= address) + goto good_area; + + if (!(vma->vm_flags & VM_GROWSDOWN)) + goto bad_area; + + if (user_mode(regs)) { + /* + * accessing the stack below usp is always a bug. + * we get page-aligned addresses so we can only check + * if we're within a page from usp, but that might be + * enough to catch brutal errors at least. + */ + if (address + PAGE_SIZE < regs->sp) + goto bad_area; + } + if (expand_stack(vma, address)) + goto bad_area; + + /* + * Ok, we have a good vm_area for this memory access, so + * we can handle it.. + */ + +good_area: + info.si_code = SEGV_ACCERR; + + /* first do some preliminary protection checks */ + + if (write_acc) { + if (!(vma->vm_flags & VM_WRITE)) + goto bad_area; + } else { + /* not present */ + if (!(vma->vm_flags & (VM_READ | VM_EXEC))) + goto bad_area; + } + + /* are we trying to execute nonexecutable area */ + if ((vector == 0x400) && !(vma->vm_page_prot.pgprot & _PAGE_EXEC)) + goto bad_area; + + /* + * If for any reason at all we couldn't handle the fault, + * make sure we exit gracefully rather than endlessly redo + * the fault. + */ + + fault = handle_mm_fault(mm, vma, address, write_acc); + if (unlikely(fault & VM_FAULT_ERROR)) { + if (fault & VM_FAULT_OOM) + goto out_of_memory; + else if (fault & VM_FAULT_SIGBUS) + goto do_sigbus; + BUG(); + } + /*RGD modeled on Cris */ + if (fault & VM_FAULT_MAJOR) + tsk->maj_flt++; + else + tsk->min_flt++; + + up_read(&mm->mmap_sem); + return; + + /* + * Something tried to access memory that isn't in our memory map.. + * Fix it, but check if it's kernel or user first.. + */ + +bad_area: + up_read(&mm->mmap_sem); + +bad_area_nosemaphore: + + /* User mode accesses just cause a SIGSEGV */ + + if (user_mode(regs)) { + info.si_signo = SIGSEGV; + info.si_errno = 0; + /* info.si_code has been set above */ + info.si_addr = (void *)address; + force_sig_info(SIGSEGV, &info, tsk); + return; + } + +no_context: + + /* Are we prepared to handle this kernel fault? + * + * (The kernel has valid exception-points in the source + * when it acesses user-memory. When it fails in one + * of those points, we find it in a table and do a jump + * to some fixup code that loads an appropriate error + * code) + */ + + { + const struct exception_table_entry *entry; + + __asm__ __volatile__("l.nop 42"); + + if ((entry = search_exception_tables(regs->pc)) != NULL) { + /* Adjust the instruction pointer in the stackframe */ + regs->pc = entry->fixup; + return; + } + } + + /* + * Oops. The kernel tried to access some bad page. We'll have to + * terminate things with extreme prejudice. + */ + + if ((unsigned long)(address) < PAGE_SIZE) + printk(KERN_ALERT + "Unable to handle kernel NULL pointer dereference"); + else + printk(KERN_ALERT "Unable to handle kernel access"); + printk(" at virtual address 0x%08lx\n", address); + + die("Oops", regs, write_acc); + + do_exit(SIGKILL); + + /* + * We ran out of memory, or some other thing happened to us that made + * us unable to handle the page fault gracefully. + */ + +out_of_memory: + __asm__ __volatile__("l.nop 42"); + __asm__ __volatile__("l.nop 1"); + + up_read(&mm->mmap_sem); + printk("VM: killing process %s\n", tsk->comm); + if (user_mode(regs)) + do_exit(SIGKILL); + goto no_context; + +do_sigbus: + up_read(&mm->mmap_sem); + + /* + * Send a sigbus, regardless of whether we were in kernel + * or user mode. + */ + info.si_signo = SIGBUS; + info.si_errno = 0; + info.si_code = BUS_ADRERR; + info.si_addr = (void *)address; + force_sig_info(SIGBUS, &info, tsk); + + /* Kernel mode? Handle exceptions or die */ + if (!user_mode(regs)) + goto no_context; + return; + +vmalloc_fault: + { + /* + * Synchronize this task's top level page-table + * with the 'reference' page table. + * + * Use current_pgd instead of tsk->active_mm->pgd + * since the latter might be unavailable if this + * code is executed in a misfortunately run irq + * (like inside schedule() between switch_mm and + * switch_to...). + */ + + int offset = pgd_index(address); + pgd_t *pgd, *pgd_k; + pud_t *pud, *pud_k; + pmd_t *pmd, *pmd_k; + pte_t *pte_k; + +/* + phx_warn("do_page_fault(): vmalloc_fault will not work, " + "since current_pgd assign a proper value somewhere\n" + "anyhow we don't need this at the moment\n"); + + phx_mmu("vmalloc_fault"); +*/ + pgd = (pgd_t *)current_pgd + offset; + pgd_k = init_mm.pgd + offset; + + /* Since we're two-level, we don't need to do both + * set_pgd and set_pmd (they do the same thing). If + * we go three-level at some point, do the right thing + * with pgd_present and set_pgd here. + * + * Also, since the vmalloc area is global, we don't + * need to copy individual PTE's, it is enough to + * copy the pgd pointer into the pte page of the + * root task. If that is there, we'll find our pte if + * it exists. + */ + + pud = pud_offset(pgd, address); + pud_k = pud_offset(pgd_k, address); + if (!pud_present(*pud_k)) + goto no_context; + + pmd = pmd_offset(pud, address); + pmd_k = pmd_offset(pud_k, address); + + if (!pmd_present(*pmd_k)) + goto bad_area_nosemaphore; + + set_pmd(pmd, *pmd_k); + + /* Make sure the actual PTE exists as well to + * catch kernel vmalloc-area accesses to non-mapped + * addresses. If we don't do this, this will just + * silently loop forever. + */ + + pte_k = pte_offset_kernel(pmd_k, address); + if (!pte_present(*pte_k)) + goto no_context; + + return; + } +} diff --git a/arch/openrisc/mm/init.c b/arch/openrisc/mm/init.c new file mode 100644 index 0000000..359dcb2 --- /dev/null +++ b/arch/openrisc/mm/init.c @@ -0,0 +1,283 @@ +/* + * OpenRISC idle.c + * + * Linux architectural port borrowing liberally from similar works of + * others. All original copyrights apply as per the original source + * declaration. + * + * Modifications for the OpenRISC architecture: + * Copyright (C) 2003 Matjaz Breskvar + * Copyright (C) 2010-2011 Jonas Bonn + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include /* for initrd_* */ +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +int mem_init_done; + +DEFINE_PER_CPU(struct mmu_gather, mmu_gathers); + +static void __init zone_sizes_init(void) +{ + unsigned long zones_size[MAX_NR_ZONES]; + + /* Clear the zone sizes */ + memset(zones_size, 0, sizeof(zones_size)); + + /* + * We use only ZONE_NORMAL + */ + zones_size[ZONE_NORMAL] = max_low_pfn; + + free_area_init(zones_size); +} + +extern const char _s_kernel_ro[], _e_kernel_ro[]; + +/* + * Map all physical memory into kernel's address space. + * + * This is explicitly coded for two-level page tables, so if you need + * something else then this needs to change. + */ +static void __init map_ram(void) +{ + unsigned long v, p, e; + pgprot_t prot; + pgd_t *pge; + pud_t *pue; + pmd_t *pme; + pte_t *pte; + /* These mark extents of read-only kernel pages... + * ...from vmlinux.lds.S + */ + struct memblock_region *region; + + v = PAGE_OFFSET; + + for_each_memblock(memory, region) { + p = (u32) region->base & PAGE_MASK; + e = p + (u32) region->size; + + v = (u32) __va(p); + pge = pgd_offset_k(v); + + while (p < e) { + int j; + pue = pud_offset(pge, v); + pme = pmd_offset(pue, v); + + if ((u32) pue != (u32) pge || (u32) pme != (u32) pge) { + panic("%s: OR1K kernel hardcoded for " + "two-level page tables", + __func__); + } + + /* Alloc one page for holding PTE's... */ + pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE); + set_pmd(pme, __pmd(_KERNPG_TABLE + __pa(pte))); + + /* Fill the newly allocated page with PTE'S */ + for (j = 0; p < e && j < PTRS_PER_PGD; + v += PAGE_SIZE, p += PAGE_SIZE, j++, pte++) { + if (v >= (u32) _e_kernel_ro || + v < (u32) _s_kernel_ro) + prot = PAGE_KERNEL; + else + prot = PAGE_KERNEL_RO; + + set_pte(pte, mk_pte_phys(p, prot)); + } + + pge++; + } + + printk(KERN_INFO "%s: Memory: 0x%x-0x%x\n", __func__, + region->base, region->base + region->size); + } +} + +void __init paging_init(void) +{ + extern void tlb_init(void); + + unsigned long end; + int i; + + printk(KERN_INFO "Setting up paging and PTEs.\n"); + + /* clear out the init_mm.pgd that will contain the kernel's mappings */ + + for (i = 0; i < PTRS_PER_PGD; i++) + swapper_pg_dir[i] = __pgd(0); + + /* make sure the current pgd table points to something sane + * (even if it is most probably not used until the next + * switch_mm) + */ + current_pgd = init_mm.pgd; + + end = (unsigned long)__va(max_low_pfn * PAGE_SIZE); + + map_ram(); + + zone_sizes_init(); + + /* self modifying code ;) */ + /* Since the old TLB miss handler has been running up until now, + * the kernel pages are still all RW, so we can still modify the + * text directly... after this change and a TLB flush, the kernel + * pages will become RO. + */ + { + extern unsigned long dtlb_miss_handler; + extern unsigned long itlb_miss_handler; + + unsigned long *dtlb_vector = __va(0x900); + unsigned long *itlb_vector = __va(0xa00); + + printk(KERN_INFO "dtlb_miss_handler %p\n", &dtlb_miss_handler); + *dtlb_vector = ((unsigned long)&dtlb_miss_handler - + (unsigned long)dtlb_vector) >> 2; + + printk(KERN_INFO "itlb_miss_handler %p\n", &itlb_miss_handler); + *itlb_vector = ((unsigned long)&itlb_miss_handler - + (unsigned long)itlb_vector) >> 2; + } + + /* Invalidate instruction caches after code modification */ + mtspr(SPR_ICBIR, 0x900); + mtspr(SPR_ICBIR, 0xa00); + + /* New TLB miss handlers and kernel page tables are in now place. + * Make sure that page flags get updated for all pages in TLB by + * flushing the TLB and forcing all TLB entries to be recreated + * from their page table flags. + */ + flush_tlb_all(); +} + +/* References to section boundaries */ + +extern char _stext, _etext, _edata, __bss_start, _end; +extern char __init_begin, __init_end; + +static int __init free_pages_init(void) +{ + int reservedpages, pfn; + + /* this will put all low memory onto the freelists */ + totalram_pages = free_all_bootmem(); + + reservedpages = 0; + for (pfn = 0; pfn < max_low_pfn; pfn++) { + /* + * Only count reserved RAM pages + */ + if (PageReserved(mem_map + pfn)) + reservedpages++; + } + + return reservedpages; +} + +static void __init set_max_mapnr_init(void) +{ + max_mapnr = num_physpages = max_low_pfn; +} + +void __init mem_init(void) +{ + int codesize, reservedpages, datasize, initsize; + + if (!mem_map) + BUG(); + + set_max_mapnr_init(); + + high_memory = (void *)__va(max_low_pfn * PAGE_SIZE); + + /* clear the zero-page */ + memset((void *)empty_zero_page, 0, PAGE_SIZE); + + reservedpages = free_pages_init(); + + codesize = (unsigned long)&_etext - (unsigned long)&_stext; + datasize = (unsigned long)&_edata - (unsigned long)&_etext; + initsize = (unsigned long)&__init_end - (unsigned long)&__init_begin; + + printk(KERN_INFO + "Memory: %luk/%luk available (%dk kernel code, %dk reserved, %dk data, %dk init, %ldk highmem)\n", + (unsigned long)nr_free_pages() << (PAGE_SHIFT - 10), + max_mapnr << (PAGE_SHIFT - 10), codesize >> 10, + reservedpages << (PAGE_SHIFT - 10), datasize >> 10, + initsize >> 10, (unsigned long)(0 << (PAGE_SHIFT - 10)) + ); + + printk("mem_init_done ...........................................\n"); + mem_init_done = 1; + return; +} + +#ifdef CONFIG_BLK_DEV_INITRD +void free_initrd_mem(unsigned long start, unsigned long end) +{ + printk(KERN_INFO "Freeing initrd memory: %ldk freed\n", + (end - start) >> 10); + + for (; start < end; start += PAGE_SIZE) { + ClearPageReserved(virt_to_page(start)); + init_page_count(virt_to_page(start)); + free_page(start); + totalram_pages++; + } +} +#endif + +void free_initmem(void) +{ + unsigned long addr; + + addr = (unsigned long)(&__init_begin); + for (; addr < (unsigned long)(&__init_end); addr += PAGE_SIZE) { + ClearPageReserved(virt_to_page(addr)); + init_page_count(virt_to_page(addr)); + free_page(addr); + totalram_pages++; + } + printk(KERN_INFO "Freeing unused kernel memory: %luk freed\n", + ((unsigned long)&__init_end - + (unsigned long)&__init_begin) >> 10); +} diff --git a/arch/openrisc/mm/ioremap.c b/arch/openrisc/mm/ioremap.c new file mode 100644 index 0000000..62b08ef --- /dev/null +++ b/arch/openrisc/mm/ioremap.c @@ -0,0 +1,137 @@ +/* + * OpenRISC ioremap.c + * + * Linux architectural port borrowing liberally from similar works of + * others. All original copyrights apply as per the original source + * declaration. + * + * Modifications for the OpenRISC architecture: + * Copyright (C) 2003 Matjaz Breskvar + * Copyright (C) 2010-2011 Jonas Bonn + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +extern int mem_init_done; + +static unsigned int fixmaps_used __initdata; + +/* + * Remap an arbitrary physical address space into the kernel virtual + * address space. Needed when the kernel wants to access high addresses + * directly. + * + * NOTE! We need to allow non-page-aligned mappings too: we will obviously + * have to convert them into an offset in a page-aligned mapping, but the + * caller shouldn't need to know that small detail. + */ +void __iomem *__init_refok +__ioremap(phys_addr_t addr, unsigned long size, pgprot_t prot) +{ + phys_addr_t p; + unsigned long v; + unsigned long offset, last_addr; + struct vm_struct *area = NULL; + + /* Don't allow wraparound or zero size */ + last_addr = addr + size - 1; + if (!size || last_addr < addr) + return NULL; + + /* + * Mappings have to be page-aligned + */ + offset = addr & ~PAGE_MASK; + p = addr & PAGE_MASK; + size = PAGE_ALIGN(last_addr + 1) - p; + + if (likely(mem_init_done)) { + area = get_vm_area(size, VM_IOREMAP); + if (!area) + return NULL; + v = (unsigned long)area->addr; + } else { + if ((fixmaps_used + (size >> PAGE_SHIFT)) > FIX_N_IOREMAPS) + return NULL; + v = fix_to_virt(FIX_IOREMAP_BEGIN + fixmaps_used); + fixmaps_used += (size >> PAGE_SHIFT); + } + + if (ioremap_page_range(v, v + size, p, prot)) { + if (likely(mem_init_done)) + vfree(area->addr); + else + fixmaps_used -= (size >> PAGE_SHIFT); + return NULL; + } + + return (void __iomem *)(offset + (char *)v); +} + +void iounmap(void *addr) +{ + /* If the page is from the fixmap pool then we just clear out + * the fixmap mapping. + */ + if (unlikely((unsigned long)addr > FIXADDR_START)) { + /* This is a bit broken... we don't really know + * how big the area is so it's difficult to know + * how many fixed pages to invalidate... + * just flush tlb and hope for the best... + * consider this a FIXME + * + * Really we should be clearing out one or more page + * table entries for these virtual addresses so that + * future references cause a page fault... for now, we + * rely on two things: + * i) this code never gets called on known boards + * ii) invalid accesses to the freed areas aren't made + */ + flush_tlb_all(); + return; + } + + return vfree((void *)(PAGE_MASK & (unsigned long)addr)); +} + +/** + * OK, this one's a bit tricky... ioremap can get called before memory is + * initialized (early serial console does this) and will want to alloc a page + * for its mapping. No userspace pages will ever get allocated before memory + * is initialized so this applies only to kernel pages. In the event that + * this is called before memory is initialized we allocate the page using + * the memblock infrastructure. + */ + +pte_t __init_refok *pte_alloc_one_kernel(struct mm_struct *mm, + unsigned long address) +{ + pte_t *pte; + + if (likely(mem_init_done)) { + pte = (pte_t *) __get_free_page(GFP_KERNEL | __GFP_REPEAT); + } else { + pte = (pte_t *) alloc_bootmem_low_pages(PAGE_SIZE); +#if 0 + /* FIXME: use memblock... */ + pte = (pte_t *) __va(memblock_alloc(PAGE_SIZE, PAGE_SIZE)); +#endif + } + + if (pte) + clear_page(pte); + return pte; +} diff --git a/arch/openrisc/mm/tlb.c b/arch/openrisc/mm/tlb.c new file mode 100644 index 0000000..56b0b89 --- /dev/null +++ b/arch/openrisc/mm/tlb.c @@ -0,0 +1,193 @@ +/* + * OpenRISC tlb.c + * + * Linux architectural port borrowing liberally from similar works of + * others. All original copyrights apply as per the original source + * declaration. + * + * Modifications for the OpenRISC architecture: + * Copyright (C) 2003 Matjaz Breskvar + * Copyright (C) 2010-2011 Julius Baxter + * Copyright (C) 2010-2011 Jonas Bonn + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include + +#define NO_CONTEXT -1 + +#define NUM_DTLB_SETS (1 << ((mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTS) >> \ + SPR_DMMUCFGR_NTS_OFF)) +#define NUM_ITLB_SETS (1 << ((mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_NTS) >> \ + SPR_IMMUCFGR_NTS_OFF)) +#define DTLB_OFFSET(addr) (((addr) >> PAGE_SHIFT) & (NUM_DTLB_SETS-1)) +#define ITLB_OFFSET(addr) (((addr) >> PAGE_SHIFT) & (NUM_ITLB_SETS-1)) +/* + * Invalidate all TLB entries. + * + * This comes down to setting the 'valid' bit for all xTLBMR registers to 0. + * Easiest way to accomplish this is to just zero out the xTLBMR register + * completely. + * + */ + +void flush_tlb_all(void) +{ + int i; + unsigned long num_tlb_sets; + + /* Determine number of sets for IMMU. */ + /* FIXME: Assumption is I & D nsets equal. */ + num_tlb_sets = NUM_ITLB_SETS; + + for (i = 0; i < num_tlb_sets; i++) { + mtspr_off(SPR_DTLBMR_BASE(0), i, 0); + mtspr_off(SPR_ITLBMR_BASE(0), i, 0); + } +} + +#define have_dtlbeir (mfspr(SPR_DMMUCFGR) & SPR_DMMUCFGR_TEIRI) +#define have_itlbeir (mfspr(SPR_IMMUCFGR) & SPR_IMMUCFGR_TEIRI) + +/* + * Invalidate a single page. This is what the xTLBEIR register is for. + * + * There's no point in checking the vma for PAGE_EXEC to determine whether it's + * the data or instruction TLB that should be flushed... that would take more + * than the few instructions that the following compiles down to! + * + * The case where we don't have the xTLBEIR register really only works for + * MMU's with a single way and is hard-coded that way. + */ + +#define flush_dtlb_page_eir(addr) mtspr(SPR_DTLBEIR, addr) +#define flush_dtlb_page_no_eir(addr) \ + mtspr_off(SPR_DTLBMR_BASE(0), DTLB_OFFSET(addr), 0); + +#define flush_itlb_page_eir(addr) mtspr(SPR_ITLBEIR, addr) +#define flush_itlb_page_no_eir(addr) \ + mtspr_off(SPR_ITLBMR_BASE(0), ITLB_OFFSET(addr), 0); + +void flush_tlb_page(struct vm_area_struct *vma, unsigned long addr) +{ + if (have_dtlbeir) + flush_dtlb_page_eir(addr); + else + flush_dtlb_page_no_eir(addr); + + if (have_itlbeir) + flush_itlb_page_eir(addr); + else + flush_itlb_page_no_eir(addr); +} + +void flush_tlb_range(struct vm_area_struct *vma, + unsigned long start, unsigned long end) +{ + int addr; + bool dtlbeir; + bool itlbeir; + + dtlbeir = have_dtlbeir; + itlbeir = have_itlbeir; + + for (addr = start; addr < end; addr += PAGE_SIZE) { + if (dtlbeir) + flush_dtlb_page_eir(addr); + else + flush_dtlb_page_no_eir(addr); + + if (itlbeir) + flush_itlb_page_eir(addr); + else + flush_itlb_page_no_eir(addr); + } +} + +/* + * Invalidate the selected mm context only. + * + * FIXME: Due to some bug here, we're flushing everything for now. + * This should be changed to loop over over mm and call flush_tlb_range. + */ + +void flush_tlb_mm(struct mm_struct *mm) +{ + + /* Was seeing bugs with the mm struct passed to us. Scrapped most of + this function. */ + /* Several architctures do this */ + flush_tlb_all(); +} + +/* called in schedule() just before actually doing the switch_to */ + +void switch_mm(struct mm_struct *prev, struct mm_struct *next, + struct task_struct *next_tsk) +{ + /* remember the pgd for the fault handlers + * this is similar to the pgd register in some other CPU's. + * we need our own copy of it because current and active_mm + * might be invalid at points where we still need to derefer + * the pgd. + */ + current_pgd = next->pgd; + + /* We don't have context support implemented, so flush all + * entries belonging to previous map + */ + + if (prev != next) + flush_tlb_mm(prev); + +} + +/* + * Initialize the context related info for a new mm_struct + * instance. + */ + +int init_new_context(struct task_struct *tsk, struct mm_struct *mm) +{ + mm->context = NO_CONTEXT; + return 0; +} + +/* called by __exit_mm to destroy the used MMU context if any before + * destroying the mm itself. this is only called when the last user of the mm + * drops it. + */ + +void destroy_context(struct mm_struct *mm) +{ + flush_tlb_mm(mm); + +} + +/* called once during VM initialization, from init.c */ + +void __init tlb_init(void) +{ + /* Do nothing... */ + /* invalidate the entire TLB */ + /* flush_tlb_all(); */ +} -- cgit v0.10.2