RISC-V: Paging and MMU
This patch contains code to manage the RISC-V MMU, including definitions of the page tables and the page walking code. Signed-off-by: Palmer Dabbelt <palmer@dabbelt.com>
This commit is contained in:
Palmer Dabbelt
parent
6d60b6ee0c
commit
07037db5d4
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@ -0,0 +1,69 @@
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/*
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* Copyright (C) 2012 Regents of the University of California
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation, version 2.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#ifndef _ASM_RISCV_MMU_CONTEXT_H
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#define _ASM_RISCV_MMU_CONTEXT_H
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#include <asm-generic/mm_hooks.h>
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#include <linux/mm.h>
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#include <linux/sched.h>
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#include <asm/tlbflush.h>
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static inline void enter_lazy_tlb(struct mm_struct *mm,
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struct task_struct *task)
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{
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}
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/* Initialize context-related info for a new mm_struct */
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static inline int init_new_context(struct task_struct *task,
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struct mm_struct *mm)
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{
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return 0;
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}
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static inline void destroy_context(struct mm_struct *mm)
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{
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}
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static inline pgd_t *current_pgdir(void)
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{
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return pfn_to_virt(csr_read(sptbr) & SPTBR_PPN);
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}
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static inline void set_pgdir(pgd_t *pgd)
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{
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csr_write(sptbr, virt_to_pfn(pgd) | SPTBR_MODE);
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}
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static inline void switch_mm(struct mm_struct *prev,
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struct mm_struct *next, struct task_struct *task)
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{
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if (likely(prev != next)) {
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set_pgdir(next->pgd);
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local_flush_tlb_all();
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}
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}
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static inline void activate_mm(struct mm_struct *prev,
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struct mm_struct *next)
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{
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switch_mm(prev, next, NULL);
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}
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static inline void deactivate_mm(struct task_struct *task,
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struct mm_struct *mm)
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{
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}
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#endif /* _ASM_RISCV_MMU_CONTEXT_H */
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@ -0,0 +1,130 @@
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/*
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* Copyright (C) 2009 Chen Liqin <liqin.chen@sunplusct.com>
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* Copyright (C) 2012 Regents of the University of California
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* Copyright (C) 2017 SiFive
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* Copyright (C) 2017 XiaojingZhu <zhuxiaoj@ict.ac.cn>
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation, version 2.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#ifndef _ASM_RISCV_PAGE_H
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#define _ASM_RISCV_PAGE_H
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#include <linux/pfn.h>
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#include <linux/const.h>
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#define PAGE_SHIFT (12)
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#define PAGE_SIZE (_AC(1, UL) << PAGE_SHIFT)
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#define PAGE_MASK (~(PAGE_SIZE - 1))
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/*
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* PAGE_OFFSET -- the first address of the first page of memory.
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* When not using MMU this corresponds to the first free page in
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* physical memory (aligned on a page boundary).
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*/
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#define PAGE_OFFSET _AC(CONFIG_PAGE_OFFSET, UL)
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#define KERN_VIRT_SIZE (-PAGE_OFFSET)
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#ifndef __ASSEMBLY__
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#define PAGE_UP(addr) (((addr)+((PAGE_SIZE)-1))&(~((PAGE_SIZE)-1)))
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#define PAGE_DOWN(addr) ((addr)&(~((PAGE_SIZE)-1)))
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/* align addr on a size boundary - adjust address up/down if needed */
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#define _ALIGN_UP(addr, size) (((addr)+((size)-1))&(~((size)-1)))
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#define _ALIGN_DOWN(addr, size) ((addr)&(~((size)-1)))
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/* align addr on a size boundary - adjust address up if needed */
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#define _ALIGN(addr, size) _ALIGN_UP(addr, size)
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#define clear_page(pgaddr) memset((pgaddr), 0, PAGE_SIZE)
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#define copy_page(to, from) memcpy((to), (from), PAGE_SIZE)
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#define clear_user_page(pgaddr, vaddr, page) memset((pgaddr), 0, PAGE_SIZE)
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#define copy_user_page(vto, vfrom, vaddr, topg) \
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memcpy((vto), (vfrom), PAGE_SIZE)
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/*
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* Use struct definitions to apply C type checking
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*/
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/* Page Global Directory entry */
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typedef struct {
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unsigned long pgd;
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} pgd_t;
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/* Page Table entry */
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typedef struct {
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unsigned long pte;
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} pte_t;
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typedef struct {
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unsigned long pgprot;
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} pgprot_t;
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typedef struct page *pgtable_t;
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#define pte_val(x) ((x).pte)
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#define pgd_val(x) ((x).pgd)
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#define pgprot_val(x) ((x).pgprot)
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#define __pte(x) ((pte_t) { (x) })
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#define __pgd(x) ((pgd_t) { (x) })
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#define __pgprot(x) ((pgprot_t) { (x) })
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#ifdef CONFIG_64BITS
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#define PTE_FMT "%016lx"
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#else
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#define PTE_FMT "%08lx"
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#endif
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extern unsigned long va_pa_offset;
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extern unsigned long pfn_base;
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extern unsigned long max_low_pfn;
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extern unsigned long min_low_pfn;
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#define __pa(x) ((unsigned long)(x) - va_pa_offset)
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#define __va(x) ((void *)((unsigned long) (x) + va_pa_offset))
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#define phys_to_pfn(phys) (PFN_DOWN(phys))
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#define pfn_to_phys(pfn) (PFN_PHYS(pfn))
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#define virt_to_pfn(vaddr) (phys_to_pfn(__pa(vaddr)))
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#define pfn_to_virt(pfn) (__va(pfn_to_phys(pfn)))
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#define virt_to_page(vaddr) (pfn_to_page(virt_to_pfn(vaddr)))
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#define page_to_virt(page) (pfn_to_virt(page_to_pfn(page)))
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#define page_to_phys(page) (pfn_to_phys(page_to_pfn(page)))
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#define page_to_bus(page) (page_to_phys(page))
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#define phys_to_page(paddr) (pfn_to_page(phys_to_pfn(paddr)))
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#define pfn_valid(pfn) \
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(((pfn) >= pfn_base) && (((pfn)-pfn_base) < max_mapnr))
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#define ARCH_PFN_OFFSET (pfn_base)
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#endif /* __ASSEMBLY__ */
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#define virt_addr_valid(vaddr) (pfn_valid(virt_to_pfn(vaddr)))
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#define VM_DATA_DEFAULT_FLAGS (VM_READ | VM_WRITE | \
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VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
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#include <asm-generic/memory_model.h>
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#include <asm-generic/getorder.h>
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/* vDSO support */
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/* We do define AT_SYSINFO_EHDR but don't use the gate mechanism */
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#define __HAVE_ARCH_GATE_AREA
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#endif /* _ASM_RISCV_PAGE_H */
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@ -0,0 +1,124 @@
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/*
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* Copyright (C) 2009 Chen Liqin <liqin.chen@sunplusct.com>
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* Copyright (C) 2012 Regents of the University of California
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation, version 2.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#ifndef _ASM_RISCV_PGALLOC_H
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#define _ASM_RISCV_PGALLOC_H
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#include <linux/mm.h>
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#include <asm/tlb.h>
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static inline void pmd_populate_kernel(struct mm_struct *mm,
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pmd_t *pmd, pte_t *pte)
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{
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unsigned long pfn = virt_to_pfn(pte);
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set_pmd(pmd, __pmd((pfn << _PAGE_PFN_SHIFT) | _PAGE_TABLE));
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}
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static inline void pmd_populate(struct mm_struct *mm,
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pmd_t *pmd, pgtable_t pte)
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{
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unsigned long pfn = virt_to_pfn(page_address(pte));
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set_pmd(pmd, __pmd((pfn << _PAGE_PFN_SHIFT) | _PAGE_TABLE));
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}
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#ifndef __PAGETABLE_PMD_FOLDED
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static inline void pud_populate(struct mm_struct *mm, pud_t *pud, pmd_t *pmd)
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{
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unsigned long pfn = virt_to_pfn(pmd);
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set_pud(pud, __pud((pfn << _PAGE_PFN_SHIFT) | _PAGE_TABLE));
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}
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#endif /* __PAGETABLE_PMD_FOLDED */
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#define pmd_pgtable(pmd) pmd_page(pmd)
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static inline pgd_t *pgd_alloc(struct mm_struct *mm)
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{
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pgd_t *pgd;
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pgd = (pgd_t *)__get_free_page(GFP_KERNEL);
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if (likely(pgd != NULL)) {
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memset(pgd, 0, USER_PTRS_PER_PGD * sizeof(pgd_t));
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/* Copy kernel mappings */
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memcpy(pgd + USER_PTRS_PER_PGD,
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init_mm.pgd + USER_PTRS_PER_PGD,
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(PTRS_PER_PGD - USER_PTRS_PER_PGD) * sizeof(pgd_t));
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}
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return pgd;
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}
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static inline void pgd_free(struct mm_struct *mm, pgd_t *pgd)
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{
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free_page((unsigned long)pgd);
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}
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#ifndef __PAGETABLE_PMD_FOLDED
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static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long addr)
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{
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return (pmd_t *)__get_free_page(
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GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_ZERO);
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}
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static inline void pmd_free(struct mm_struct *mm, pmd_t *pmd)
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{
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free_page((unsigned long)pmd);
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}
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#define __pmd_free_tlb(tlb, pmd, addr) pmd_free((tlb)->mm, pmd)
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#endif /* __PAGETABLE_PMD_FOLDED */
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static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm,
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unsigned long address)
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{
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return (pte_t *)__get_free_page(
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GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_ZERO);
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}
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static inline struct page *pte_alloc_one(struct mm_struct *mm,
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unsigned long address)
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{
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struct page *pte;
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pte = alloc_page(GFP_KERNEL | __GFP_RETRY_MAYFAIL | __GFP_ZERO);
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if (likely(pte != NULL))
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pgtable_page_ctor(pte);
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return pte;
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}
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static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
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{
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free_page((unsigned long)pte);
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}
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static inline void pte_free(struct mm_struct *mm, pgtable_t pte)
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{
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pgtable_page_dtor(pte);
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__free_page(pte);
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}
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#define __pte_free_tlb(tlb, pte, buf) \
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do { \
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pgtable_page_dtor(pte); \
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tlb_remove_page((tlb), pte); \
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} while (0)
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static inline void check_pgt_cache(void)
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{
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}
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#endif /* _ASM_RISCV_PGALLOC_H */
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@ -0,0 +1,25 @@
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/*
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* Copyright (C) 2012 Regents of the University of California
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation, version 2.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#ifndef _ASM_RISCV_PGTABLE_32_H
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#define _ASM_RISCV_PGTABLE_32_H
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#include <asm-generic/pgtable-nopmd.h>
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#include <linux/const.h>
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/* Size of region mapped by a page global directory */
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#define PGDIR_SHIFT 22
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#define PGDIR_SIZE (_AC(1, UL) << PGDIR_SHIFT)
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#define PGDIR_MASK (~(PGDIR_SIZE - 1))
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#endif /* _ASM_RISCV_PGTABLE_32_H */
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/*
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* Copyright (C) 2012 Regents of the University of California
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*
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* This program is free software; you can redistribute it and/or
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* modify it under the terms of the GNU General Public License
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* as published by the Free Software Foundation, version 2.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*/
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#ifndef _ASM_RISCV_PGTABLE_64_H
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#define _ASM_RISCV_PGTABLE_64_H
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#include <linux/const.h>
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#define PGDIR_SHIFT 30
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/* Size of region mapped by a page global directory */
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#define PGDIR_SIZE (_AC(1, UL) << PGDIR_SHIFT)
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#define PGDIR_MASK (~(PGDIR_SIZE - 1))
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#define PMD_SHIFT 21
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/* Size of region mapped by a page middle directory */
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#define PMD_SIZE (_AC(1, UL) << PMD_SHIFT)
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#define PMD_MASK (~(PMD_SIZE - 1))
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/* Page Middle Directory entry */
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typedef struct {
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unsigned long pmd;
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} pmd_t;
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#define pmd_val(x) ((x).pmd)
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#define __pmd(x) ((pmd_t) { (x) })
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#define PTRS_PER_PMD (PAGE_SIZE / sizeof(pmd_t))
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static inline int pud_present(pud_t pud)
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{
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return (pud_val(pud) & _PAGE_PRESENT);
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}
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static inline int pud_none(pud_t pud)
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{
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return (pud_val(pud) == 0);
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}
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static inline int pud_bad(pud_t pud)
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{
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return !pud_present(pud);
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}
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static inline void set_pud(pud_t *pudp, pud_t pud)
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{
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*pudp = pud;
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}
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static inline void pud_clear(pud_t *pudp)
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{
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set_pud(pudp, __pud(0));
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}
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static inline unsigned long pud_page_vaddr(pud_t pud)
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{
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return (unsigned long)pfn_to_virt(pud_val(pud) >> _PAGE_PFN_SHIFT);
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}
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#define pmd_index(addr) (((addr) >> PMD_SHIFT) & (PTRS_PER_PMD - 1))
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static inline pmd_t *pmd_offset(pud_t *pud, unsigned long addr)
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{
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return (pmd_t *)pud_page_vaddr(*pud) + pmd_index(addr);
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}
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static inline pmd_t pfn_pmd(unsigned long pfn, pgprot_t prot)
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{
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return __pmd((pfn << _PAGE_PFN_SHIFT) | pgprot_val(prot));
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}
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#define pmd_ERROR(e) \
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pr_err("%s:%d: bad pmd %016lx.\n", __FILE__, __LINE__, pmd_val(e))
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#endif /* _ASM_RISCV_PGTABLE_64_H */
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@ -0,0 +1,48 @@
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/*
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* Copyright (C) 2012 Regents of the University of California
|
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*
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||||
* 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, version 2.
|
||||
*
|
||||
* This program is distributed in the hope that it will be useful,
|
||||
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
* GNU General Public License for more details.
|
||||
*/
|
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|
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#ifndef _ASM_RISCV_PGTABLE_BITS_H
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#define _ASM_RISCV_PGTABLE_BITS_H
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/*
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* PTE format:
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* | XLEN-1 10 | 9 8 | 7 | 6 | 5 | 4 | 3 | 2 | 1 | 0
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* PFN reserved for SW D A G U X W R V
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*/
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#define _PAGE_ACCESSED_OFFSET 6
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#define _PAGE_PRESENT (1 << 0)
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#define _PAGE_READ (1 << 1) /* Readable */
|
||||
#define _PAGE_WRITE (1 << 2) /* Writable */
|
||||
#define _PAGE_EXEC (1 << 3) /* Executable */
|
||||
#define _PAGE_USER (1 << 4) /* User */
|
||||
#define _PAGE_GLOBAL (1 << 5) /* Global */
|
||||
#define _PAGE_ACCESSED (1 << 6) /* Set by hardware on any access */
|
||||
#define _PAGE_DIRTY (1 << 7) /* Set by hardware on any write */
|
||||
#define _PAGE_SOFT (1 << 8) /* Reserved for software */
|
||||
|
||||
#define _PAGE_SPECIAL _PAGE_SOFT
|
||||
#define _PAGE_TABLE _PAGE_PRESENT
|
||||
|
||||
#define _PAGE_PFN_SHIFT 10
|
||||
|
||||
/* Set of bits to preserve across pte_modify() */
|
||||
#define _PAGE_CHG_MASK (~(unsigned long)(_PAGE_PRESENT | _PAGE_READ | \
|
||||
_PAGE_WRITE | _PAGE_EXEC | \
|
||||
_PAGE_USER | _PAGE_GLOBAL))
|
||||
|
||||
/* Advertise support for _PAGE_SPECIAL */
|
||||
#define __HAVE_ARCH_PTE_SPECIAL
|
||||
|
||||
#endif /* _ASM_RISCV_PGTABLE_BITS_H */
|
||||
|
|
@ -0,0 +1,430 @@
|
|||
/*
|
||||
* Copyright (C) 2012 Regents of the University of California
|
||||
*
|
||||
* 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, version 2.
|
||||
*
|
||||
* This program is distributed in the hope that it will be useful,
|
||||
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
* GNU General Public License for more details.
|
||||
*/
|
||||
|
||||
#ifndef _ASM_RISCV_PGTABLE_H
|
||||
#define _ASM_RISCV_PGTABLE_H
|
||||
|
||||
#include <linux/mmzone.h>
|
||||
|
||||
#include <asm/pgtable-bits.h>
|
||||
|
||||
#ifndef __ASSEMBLY__
|
||||
|
||||
#ifdef CONFIG_MMU
|
||||
|
||||
/* Page Upper Directory not used in RISC-V */
|
||||
#include <asm-generic/pgtable-nopud.h>
|
||||
#include <asm/page.h>
|
||||
#include <asm/tlbflush.h>
|
||||
#include <linux/mm_types.h>
|
||||
|
||||
#ifdef CONFIG_64BIT
|
||||
#include <asm/pgtable-64.h>
|
||||
#else
|
||||
#include <asm/pgtable-32.h>
|
||||
#endif /* CONFIG_64BIT */
|
||||
|
||||
/* Number of entries in the page global directory */
|
||||
#define PTRS_PER_PGD (PAGE_SIZE / sizeof(pgd_t))
|
||||
/* Number of entries in the page table */
|
||||
#define PTRS_PER_PTE (PAGE_SIZE / sizeof(pte_t))
|
||||
|
||||
/* Number of PGD entries that a user-mode program can use */
|
||||
#define USER_PTRS_PER_PGD (TASK_SIZE / PGDIR_SIZE)
|
||||
#define FIRST_USER_ADDRESS 0
|
||||
|
||||
/* Page protection bits */
|
||||
#define _PAGE_BASE (_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_USER)
|
||||
|
||||
#define PAGE_NONE __pgprot(0)
|
||||
#define PAGE_READ __pgprot(_PAGE_BASE | _PAGE_READ)
|
||||
#define PAGE_WRITE __pgprot(_PAGE_BASE | _PAGE_READ | _PAGE_WRITE)
|
||||
#define PAGE_EXEC __pgprot(_PAGE_BASE | _PAGE_EXEC)
|
||||
#define PAGE_READ_EXEC __pgprot(_PAGE_BASE | _PAGE_READ | _PAGE_EXEC)
|
||||
#define PAGE_WRITE_EXEC __pgprot(_PAGE_BASE | _PAGE_READ | \
|
||||
_PAGE_EXEC | _PAGE_WRITE)
|
||||
|
||||
#define PAGE_COPY PAGE_READ
|
||||
#define PAGE_COPY_EXEC PAGE_EXEC
|
||||
#define PAGE_COPY_READ_EXEC PAGE_READ_EXEC
|
||||
#define PAGE_SHARED PAGE_WRITE
|
||||
#define PAGE_SHARED_EXEC PAGE_WRITE_EXEC
|
||||
|
||||
#define _PAGE_KERNEL (_PAGE_READ \
|
||||
| _PAGE_WRITE \
|
||||
| _PAGE_PRESENT \
|
||||
| _PAGE_ACCESSED \
|
||||
| _PAGE_DIRTY)
|
||||
|
||||
#define PAGE_KERNEL __pgprot(_PAGE_KERNEL)
|
||||
#define PAGE_KERNEL_EXEC __pgprot(_PAGE_KERNEL | _PAGE_EXEC)
|
||||
|
||||
extern pgd_t swapper_pg_dir[];
|
||||
|
||||
/* MAP_PRIVATE permissions: xwr (copy-on-write) */
|
||||
#define __P000 PAGE_NONE
|
||||
#define __P001 PAGE_READ
|
||||
#define __P010 PAGE_COPY
|
||||
#define __P011 PAGE_COPY
|
||||
#define __P100 PAGE_EXEC
|
||||
#define __P101 PAGE_READ_EXEC
|
||||
#define __P110 PAGE_COPY_EXEC
|
||||
#define __P111 PAGE_COPY_READ_EXEC
|
||||
|
||||
/* MAP_SHARED permissions: xwr */
|
||||
#define __S000 PAGE_NONE
|
||||
#define __S001 PAGE_READ
|
||||
#define __S010 PAGE_SHARED
|
||||
#define __S011 PAGE_SHARED
|
||||
#define __S100 PAGE_EXEC
|
||||
#define __S101 PAGE_READ_EXEC
|
||||
#define __S110 PAGE_SHARED_EXEC
|
||||
#define __S111 PAGE_SHARED_EXEC
|
||||
|
||||
/*
|
||||
* ZERO_PAGE is a global shared page that is always zero,
|
||||
* used for zero-mapped memory areas, etc.
|
||||
*/
|
||||
extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
|
||||
#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
|
||||
|
||||
static inline int pmd_present(pmd_t pmd)
|
||||
{
|
||||
return (pmd_val(pmd) & _PAGE_PRESENT);
|
||||
}
|
||||
|
||||
static inline int pmd_none(pmd_t pmd)
|
||||
{
|
||||
return (pmd_val(pmd) == 0);
|
||||
}
|
||||
|
||||
static inline int pmd_bad(pmd_t pmd)
|
||||
{
|
||||
return !pmd_present(pmd);
|
||||
}
|
||||
|
||||
static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
|
||||
{
|
||||
*pmdp = pmd;
|
||||
}
|
||||
|
||||
static inline void pmd_clear(pmd_t *pmdp)
|
||||
{
|
||||
set_pmd(pmdp, __pmd(0));
|
||||
}
|
||||
|
||||
|
||||
static inline pgd_t pfn_pgd(unsigned long pfn, pgprot_t prot)
|
||||
{
|
||||
return __pgd((pfn << _PAGE_PFN_SHIFT) | pgprot_val(prot));
|
||||
}
|
||||
|
||||
#define pgd_index(addr) (((addr) >> PGDIR_SHIFT) & (PTRS_PER_PGD - 1))
|
||||
|
||||
/* Locate an entry in the page global directory */
|
||||
static inline pgd_t *pgd_offset(const struct mm_struct *mm, unsigned long addr)
|
||||
{
|
||||
return mm->pgd + pgd_index(addr);
|
||||
}
|
||||
/* Locate an entry in the kernel page global directory */
|
||||
#define pgd_offset_k(addr) pgd_offset(&init_mm, (addr))
|
||||
|
||||
static inline struct page *pmd_page(pmd_t pmd)
|
||||
{
|
||||
return pfn_to_page(pmd_val(pmd) >> _PAGE_PFN_SHIFT);
|
||||
}
|
||||
|
||||
static inline unsigned long pmd_page_vaddr(pmd_t pmd)
|
||||
{
|
||||
return (unsigned long)pfn_to_virt(pmd_val(pmd) >> _PAGE_PFN_SHIFT);
|
||||
}
|
||||
|
||||
/* Yields the page frame number (PFN) of a page table entry */
|
||||
static inline unsigned long pte_pfn(pte_t pte)
|
||||
{
|
||||
return (pte_val(pte) >> _PAGE_PFN_SHIFT);
|
||||
}
|
||||
|
||||
#define pte_page(x) pfn_to_page(pte_pfn(x))
|
||||
|
||||
/* Constructs a page table entry */
|
||||
static inline pte_t pfn_pte(unsigned long pfn, pgprot_t prot)
|
||||
{
|
||||
return __pte((pfn << _PAGE_PFN_SHIFT) | pgprot_val(prot));
|
||||
}
|
||||
|
||||
static inline pte_t mk_pte(struct page *page, pgprot_t prot)
|
||||
{
|
||||
return pfn_pte(page_to_pfn(page), prot);
|
||||
}
|
||||
|
||||
#define pte_index(addr) (((addr) >> PAGE_SHIFT) & (PTRS_PER_PTE - 1))
|
||||
|
||||
static inline pte_t *pte_offset_kernel(pmd_t *pmd, unsigned long addr)
|
||||
{
|
||||
return (pte_t *)pmd_page_vaddr(*pmd) + pte_index(addr);
|
||||
}
|
||||
|
||||
#define pte_offset_map(dir, addr) pte_offset_kernel((dir), (addr))
|
||||
#define pte_unmap(pte) ((void)(pte))
|
||||
|
||||
/*
|
||||
* Certain architectures need to do special things when PTEs within
|
||||
* a page table are directly modified. Thus, the following hook is
|
||||
* made available.
|
||||
*/
|
||||
static inline void set_pte(pte_t *ptep, pte_t pteval)
|
||||
{
|
||||
*ptep = pteval;
|
||||
}
|
||||
|
||||
static inline void set_pte_at(struct mm_struct *mm,
|
||||
unsigned long addr, pte_t *ptep, pte_t pteval)
|
||||
{
|
||||
set_pte(ptep, pteval);
|
||||
}
|
||||
|
||||
static inline void pte_clear(struct mm_struct *mm,
|
||||
unsigned long addr, pte_t *ptep)
|
||||
{
|
||||
set_pte_at(mm, addr, ptep, __pte(0));
|
||||
}
|
||||
|
||||
static inline int pte_present(pte_t pte)
|
||||
{
|
||||
return (pte_val(pte) & _PAGE_PRESENT);
|
||||
}
|
||||
|
||||
static inline int pte_none(pte_t pte)
|
||||
{
|
||||
return (pte_val(pte) == 0);
|
||||
}
|
||||
|
||||
/* static inline int pte_read(pte_t pte) */
|
||||
|
||||
static inline int pte_write(pte_t pte)
|
||||
{
|
||||
return pte_val(pte) & _PAGE_WRITE;
|
||||
}
|
||||
|
||||
static inline int pte_huge(pte_t pte)
|
||||
{
|
||||
return pte_present(pte)
|
||||
&& (pte_val(pte) & (_PAGE_READ | _PAGE_WRITE | _PAGE_EXEC));
|
||||
}
|
||||
|
||||
/* static inline int pte_exec(pte_t pte) */
|
||||
|
||||
static inline int pte_dirty(pte_t pte)
|
||||
{
|
||||
return pte_val(pte) & _PAGE_DIRTY;
|
||||
}
|
||||
|
||||
static inline int pte_young(pte_t pte)
|
||||
{
|
||||
return pte_val(pte) & _PAGE_ACCESSED;
|
||||
}
|
||||
|
||||
static inline int pte_special(pte_t pte)
|
||||
{
|
||||
return pte_val(pte) & _PAGE_SPECIAL;
|
||||
}
|
||||
|
||||
/* static inline pte_t pte_rdprotect(pte_t pte) */
|
||||
|
||||
static inline pte_t pte_wrprotect(pte_t pte)
|
||||
{
|
||||
return __pte(pte_val(pte) & ~(_PAGE_WRITE));
|
||||
}
|
||||
|
||||
/* static inline pte_t pte_mkread(pte_t pte) */
|
||||
|
||||
static inline pte_t pte_mkwrite(pte_t pte)
|
||||
{
|
||||
return __pte(pte_val(pte) | _PAGE_WRITE);
|
||||
}
|
||||
|
||||
/* static inline pte_t pte_mkexec(pte_t pte) */
|
||||
|
||||
static inline pte_t pte_mkdirty(pte_t pte)
|
||||
{
|
||||
return __pte(pte_val(pte) | _PAGE_DIRTY);
|
||||
}
|
||||
|
||||
static inline pte_t pte_mkclean(pte_t pte)
|
||||
{
|
||||
return __pte(pte_val(pte) & ~(_PAGE_DIRTY));
|
||||
}
|
||||
|
||||
static inline pte_t pte_mkyoung(pte_t pte)
|
||||
{
|
||||
return __pte(pte_val(pte) | _PAGE_ACCESSED);
|
||||
}
|
||||
|
||||
static inline pte_t pte_mkold(pte_t pte)
|
||||
{
|
||||
return __pte(pte_val(pte) & ~(_PAGE_ACCESSED));
|
||||
}
|
||||
|
||||
static inline pte_t pte_mkspecial(pte_t pte)
|
||||
{
|
||||
return __pte(pte_val(pte) | _PAGE_SPECIAL);
|
||||
}
|
||||
|
||||
/* Modify page protection bits */
|
||||
static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
|
||||
{
|
||||
return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot));
|
||||
}
|
||||
|
||||
#define pgd_ERROR(e) \
|
||||
pr_err("%s:%d: bad pgd " PTE_FMT ".\n", __FILE__, __LINE__, pgd_val(e))
|
||||
|
||||
|
||||
/* Commit new configuration to MMU hardware */
|
||||
static inline void update_mmu_cache(struct vm_area_struct *vma,
|
||||
unsigned long address, pte_t *ptep)
|
||||
{
|
||||
/*
|
||||
* The kernel assumes that TLBs don't cache invalid entries, but
|
||||
* in RISC-V, SFENCE.VMA specifies an ordering constraint, not a
|
||||
* cache flush; it is necessary even after writing invalid entries.
|
||||
* Relying on flush_tlb_fix_spurious_fault would suffice, but
|
||||
* the extra traps reduce performance. So, eagerly SFENCE.VMA.
|
||||
*/
|
||||
local_flush_tlb_page(address);
|
||||
}
|
||||
|
||||
#define __HAVE_ARCH_PTE_SAME
|
||||
static inline int pte_same(pte_t pte_a, pte_t pte_b)
|
||||
{
|
||||
return pte_val(pte_a) == pte_val(pte_b);
|
||||
}
|
||||
|
||||
#define __HAVE_ARCH_PTEP_SET_ACCESS_FLAGS
|
||||
static inline int ptep_set_access_flags(struct vm_area_struct *vma,
|
||||
unsigned long address, pte_t *ptep,
|
||||
pte_t entry, int dirty)
|
||||
{
|
||||
if (!pte_same(*ptep, entry))
|
||||
set_pte_at(vma->vm_mm, address, ptep, entry);
|
||||
/*
|
||||
* update_mmu_cache will unconditionally execute, handling both
|
||||
* the case that the PTE changed and the spurious fault case.
|
||||
*/
|
||||
return true;
|
||||
}
|
||||
|
||||
#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
|
||||
static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
|
||||
unsigned long address, pte_t *ptep)
|
||||
{
|
||||
return __pte(atomic_long_xchg((atomic_long_t *)ptep, 0));
|
||||
}
|
||||
|
||||
#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
|
||||
static inline int ptep_test_and_clear_young(struct vm_area_struct *vma,
|
||||
unsigned long address,
|
||||
pte_t *ptep)
|
||||
{
|
||||
if (!pte_young(*ptep))
|
||||
return 0;
|
||||
return test_and_clear_bit(_PAGE_ACCESSED_OFFSET, &pte_val(*ptep));
|
||||
}
|
||||
|
||||
#define __HAVE_ARCH_PTEP_SET_WRPROTECT
|
||||
static inline void ptep_set_wrprotect(struct mm_struct *mm,
|
||||
unsigned long address, pte_t *ptep)
|
||||
{
|
||||
atomic_long_and(~(unsigned long)_PAGE_WRITE, (atomic_long_t *)ptep);
|
||||
}
|
||||
|
||||
#define __HAVE_ARCH_PTEP_CLEAR_YOUNG_FLUSH
|
||||
static inline int ptep_clear_flush_young(struct vm_area_struct *vma,
|
||||
unsigned long address, pte_t *ptep)
|
||||
{
|
||||
/*
|
||||
* This comment is borrowed from x86, but applies equally to RISC-V:
|
||||
*
|
||||
* Clearing the accessed bit without a TLB flush
|
||||
* doesn't cause data corruption. [ It could cause incorrect
|
||||
* page aging and the (mistaken) reclaim of hot pages, but the
|
||||
* chance of that should be relatively low. ]
|
||||
*
|
||||
* So as a performance optimization don't flush the TLB when
|
||||
* clearing the accessed bit, it will eventually be flushed by
|
||||
* a context switch or a VM operation anyway. [ In the rare
|
||||
* event of it not getting flushed for a long time the delay
|
||||
* shouldn't really matter because there's no real memory
|
||||
* pressure for swapout to react to. ]
|
||||
*/
|
||||
return ptep_test_and_clear_young(vma, address, ptep);
|
||||
}
|
||||
|
||||
/*
|
||||
* Encode and decode a swap entry
|
||||
*
|
||||
* Format of swap PTE:
|
||||
* bit 0: _PAGE_PRESENT (zero)
|
||||
* bit 1: reserved for future use (zero)
|
||||
* bits 2 to 6: swap type
|
||||
* bits 7 to XLEN-1: swap offset
|
||||
*/
|
||||
#define __SWP_TYPE_SHIFT 2
|
||||
#define __SWP_TYPE_BITS 5
|
||||
#define __SWP_TYPE_MASK ((1UL << __SWP_TYPE_BITS) - 1)
|
||||
#define __SWP_OFFSET_SHIFT (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
|
||||
|
||||
#define MAX_SWAPFILES_CHECK() \
|
||||
BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > __SWP_TYPE_BITS)
|
||||
|
||||
#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(x) ((pte_t) { (x).val })
|
||||
|
||||
#ifdef CONFIG_FLATMEM
|
||||
#define kern_addr_valid(addr) (1) /* FIXME */
|
||||
#endif
|
||||
|
||||
extern void paging_init(void);
|
||||
|
||||
static inline void pgtable_cache_init(void)
|
||||
{
|
||||
/* No page table caches to initialize */
|
||||
}
|
||||
|
||||
#endif /* CONFIG_MMU */
|
||||
|
||||
#define VMALLOC_SIZE (KERN_VIRT_SIZE >> 1)
|
||||
#define VMALLOC_END (PAGE_OFFSET - 1)
|
||||
#define VMALLOC_START (PAGE_OFFSET - VMALLOC_SIZE)
|
||||
|
||||
/*
|
||||
* Task size is 0x40000000000 for RV64 or 0xb800000 for RV32.
|
||||
* Note that PGDIR_SIZE must evenly divide TASK_SIZE.
|
||||
*/
|
||||
#ifdef CONFIG_64BIT
|
||||
#define TASK_SIZE (PGDIR_SIZE * PTRS_PER_PGD / 2)
|
||||
#else
|
||||
#define TASK_SIZE VMALLOC_START
|
||||
#endif
|
||||
|
||||
#include <asm-generic/pgtable.h>
|
||||
|
||||
#endif /* !__ASSEMBLY__ */
|
||||
|
||||
#endif /* _ASM_RISCV_PGTABLE_H */
|
||||
|
|
@ -0,0 +1,282 @@
|
|||
/*
|
||||
* Copyright (C) 2009 Sunplus Core Technology Co., Ltd.
|
||||
* Lennox Wu <lennox.wu@sunplusct.com>
|
||||
* Chen Liqin <liqin.chen@sunplusct.com>
|
||||
* Copyright (C) 2012 Regents of the University of California
|
||||
*
|
||||
* 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.
|
||||
*
|
||||
* This program is distributed in the hope that it will be useful,
|
||||
* but WITHOUT ANY WARRANTY; without even the implied warranty of
|
||||
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
||||
* GNU General Public License for more details.
|
||||
*
|
||||
* You should have received a copy of the GNU General Public License
|
||||
* along with this program; if not, see the file COPYING, or write
|
||||
* to the Free Software Foundation, Inc.,
|
||||
*/
|
||||
|
||||
|
||||
#include <linux/mm.h>
|
||||
#include <linux/kernel.h>
|
||||
#include <linux/interrupt.h>
|
||||
#include <linux/perf_event.h>
|
||||
#include <linux/signal.h>
|
||||
#include <linux/uaccess.h>
|
||||
|
||||
#include <asm/pgalloc.h>
|
||||
#include <asm/ptrace.h>
|
||||
#include <asm/uaccess.h>
|
||||
|
||||
/*
|
||||
* This routine handles page faults. It determines the address and the
|
||||
* problem, and then passes it off to one of the appropriate routines.
|
||||
*/
|
||||
asmlinkage void do_page_fault(struct pt_regs *regs)
|
||||
{
|
||||
struct task_struct *tsk;
|
||||
struct vm_area_struct *vma;
|
||||
struct mm_struct *mm;
|
||||
unsigned long addr, cause;
|
||||
unsigned int flags = FAULT_FLAG_ALLOW_RETRY | FAULT_FLAG_KILLABLE;
|
||||
int fault, code = SEGV_MAPERR;
|
||||
|
||||
cause = regs->scause;
|
||||
addr = regs->sbadaddr;
|
||||
|
||||
tsk = current;
|
||||
mm = tsk->mm;
|
||||
|
||||
/*
|
||||
* 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.
|
||||
*/
|
||||
if (unlikely((addr >= VMALLOC_START) && (addr <= VMALLOC_END)))
|
||||
goto vmalloc_fault;
|
||||
|
||||
/* Enable interrupts if they were enabled in the parent context. */
|
||||
if (likely(regs->sstatus & SR_PIE))
|
||||
local_irq_enable();
|
||||
|
||||
/*
|
||||
* If we're in an interrupt, have no user context, or are running
|
||||
* in an atomic region, then we must not take the fault.
|
||||
*/
|
||||
if (unlikely(faulthandler_disabled() || !mm))
|
||||
goto no_context;
|
||||
|
||||
if (user_mode(regs))
|
||||
flags |= FAULT_FLAG_USER;
|
||||
|
||||
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS, 1, regs, addr);
|
||||
|
||||
retry:
|
||||
down_read(&mm->mmap_sem);
|
||||
vma = find_vma(mm, addr);
|
||||
if (unlikely(!vma))
|
||||
goto bad_area;
|
||||
if (likely(vma->vm_start <= addr))
|
||||
goto good_area;
|
||||
if (unlikely(!(vma->vm_flags & VM_GROWSDOWN)))
|
||||
goto bad_area;
|
||||
if (unlikely(expand_stack(vma, addr)))
|
||||
goto bad_area;
|
||||
|
||||
/*
|
||||
* Ok, we have a good vm_area for this memory access, so
|
||||
* we can handle it.
|
||||
*/
|
||||
good_area:
|
||||
code = SEGV_ACCERR;
|
||||
|
||||
switch (cause) {
|
||||
case EXC_INST_PAGE_FAULT:
|
||||
if (!(vma->vm_flags & VM_EXEC))
|
||||
goto bad_area;
|
||||
break;
|
||||
case EXC_LOAD_PAGE_FAULT:
|
||||
if (!(vma->vm_flags & VM_READ))
|
||||
goto bad_area;
|
||||
break;
|
||||
case EXC_STORE_PAGE_FAULT:
|
||||
if (!(vma->vm_flags & VM_WRITE))
|
||||
goto bad_area;
|
||||
flags |= FAULT_FLAG_WRITE;
|
||||
break;
|
||||
default:
|
||||
panic("%s: unhandled cause %lu", __func__, cause);
|
||||
}
|
||||
|
||||
/*
|
||||
* If for any reason at all we could not handle the fault,
|
||||
* make sure we exit gracefully rather than endlessly redo
|
||||
* the fault.
|
||||
*/
|
||||
fault = handle_mm_fault(vma, addr, flags);
|
||||
|
||||
/*
|
||||
* If we need to retry but a fatal signal is pending, handle the
|
||||
* signal first. We do not need to release the mmap_sem because it
|
||||
* would already be released in __lock_page_or_retry in mm/filemap.c.
|
||||
*/
|
||||
if ((fault & VM_FAULT_RETRY) && fatal_signal_pending(tsk))
|
||||
return;
|
||||
|
||||
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();
|
||||
}
|
||||
|
||||
/*
|
||||
* Major/minor page fault accounting is only done on the
|
||||
* initial attempt. If we go through a retry, it is extremely
|
||||
* likely that the page will be found in page cache at that point.
|
||||
*/
|
||||
if (flags & FAULT_FLAG_ALLOW_RETRY) {
|
||||
if (fault & VM_FAULT_MAJOR) {
|
||||
tsk->maj_flt++;
|
||||
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MAJ,
|
||||
1, regs, addr);
|
||||
} else {
|
||||
tsk->min_flt++;
|
||||
perf_sw_event(PERF_COUNT_SW_PAGE_FAULTS_MIN,
|
||||
1, regs, addr);
|
||||
}
|
||||
if (fault & VM_FAULT_RETRY) {
|
||||
/*
|
||||
* Clear FAULT_FLAG_ALLOW_RETRY to avoid any risk
|
||||
* of starvation.
|
||||
*/
|
||||
flags &= ~(FAULT_FLAG_ALLOW_RETRY);
|
||||
flags |= FAULT_FLAG_TRIED;
|
||||
|
||||
/*
|
||||
* No need to up_read(&mm->mmap_sem) as we would
|
||||
* have already released it in __lock_page_or_retry
|
||||
* in mm/filemap.c.
|
||||
*/
|
||||
goto retry;
|
||||
}
|
||||
}
|
||||
|
||||
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);
|
||||
/* User mode accesses just cause a SIGSEGV */
|
||||
if (user_mode(regs)) {
|
||||
do_trap(regs, SIGSEGV, code, addr, tsk);
|
||||
return;
|
||||
}
|
||||
|
||||
no_context:
|
||||
/* Are we prepared to handle this kernel fault? */
|
||||
if (fixup_exception(regs))
|
||||
return;
|
||||
|
||||
/*
|
||||
* Oops. The kernel tried to access some bad page. We'll have to
|
||||
* terminate things with extreme prejudice.
|
||||
*/
|
||||
bust_spinlocks(1);
|
||||
pr_alert("Unable to handle kernel %s at virtual address " REG_FMT "\n",
|
||||
(addr < PAGE_SIZE) ? "NULL pointer dereference" :
|
||||
"paging request", addr);
|
||||
die(regs, "Oops");
|
||||
do_exit(SIGKILL);
|
||||
|
||||
/*
|
||||
* We ran out of memory, call the OOM killer, and return the userspace
|
||||
* (which will retry the fault, or kill us if we got oom-killed).
|
||||
*/
|
||||
out_of_memory:
|
||||
up_read(&mm->mmap_sem);
|
||||
if (!user_mode(regs))
|
||||
goto no_context;
|
||||
pagefault_out_of_memory();
|
||||
return;
|
||||
|
||||
do_sigbus:
|
||||
up_read(&mm->mmap_sem);
|
||||
/* Kernel mode? Handle exceptions or die */
|
||||
if (!user_mode(regs))
|
||||
goto no_context;
|
||||
do_trap(regs, SIGBUS, BUS_ADRERR, addr, tsk);
|
||||
return;
|
||||
|
||||
vmalloc_fault:
|
||||
{
|
||||
pgd_t *pgd, *pgd_k;
|
||||
pud_t *pud, *pud_k;
|
||||
p4d_t *p4d, *p4d_k;
|
||||
pmd_t *pmd, *pmd_k;
|
||||
pte_t *pte_k;
|
||||
int index;
|
||||
|
||||
if (user_mode(regs))
|
||||
goto bad_area;
|
||||
|
||||
/*
|
||||
* Synchronize this task's top level page-table
|
||||
* with the 'reference' page table.
|
||||
*
|
||||
* Do _not_ use "tsk->active_mm->pgd" here.
|
||||
* We might be inside an interrupt in the middle
|
||||
* of a task switch.
|
||||
*/
|
||||
index = pgd_index(addr);
|
||||
pgd = (pgd_t *)pfn_to_virt(csr_read(sptbr)) + index;
|
||||
pgd_k = init_mm.pgd + index;
|
||||
|
||||
if (!pgd_present(*pgd_k))
|
||||
goto no_context;
|
||||
set_pgd(pgd, *pgd_k);
|
||||
|
||||
p4d = p4d_offset(pgd, addr);
|
||||
p4d_k = p4d_offset(pgd_k, addr);
|
||||
if (!p4d_present(*p4d_k))
|
||||
goto no_context;
|
||||
|
||||
pud = pud_offset(p4d, addr);
|
||||
pud_k = pud_offset(p4d_k, addr);
|
||||
if (!pud_present(*pud_k))
|
||||
goto no_context;
|
||||
|
||||
/*
|
||||
* Since the vmalloc area is global, it is unnecessary
|
||||
* to copy individual PTEs
|
||||
*/
|
||||
pmd = pmd_offset(pud, addr);
|
||||
pmd_k = pmd_offset(pud_k, addr);
|
||||
if (!pmd_present(*pmd_k))
|
||||
goto no_context;
|
||||
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, addr);
|
||||
if (!pte_present(*pte_k))
|
||||
goto no_context;
|
||||
return;
|
||||
}
|
||||
}
|
||||
Loading…
Reference in New Issue