244 lines
5.2 KiB
C
244 lines
5.2 KiB
C
// SPDX-License-Identifier: GPL-2.0-only
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/*
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* Copyright (C) 2019 SiFive
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*/
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#include <linux/pagewalk.h>
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#include <linux/pgtable.h>
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#include <asm/tlbflush.h>
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#include <asm/bitops.h>
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#include <asm/set_memory.h>
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struct pageattr_masks {
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pgprot_t set_mask;
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pgprot_t clear_mask;
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};
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static unsigned long set_pageattr_masks(unsigned long val, struct mm_walk *walk)
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{
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struct pageattr_masks *masks = walk->private;
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unsigned long new_val = val;
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new_val &= ~(pgprot_val(masks->clear_mask));
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new_val |= (pgprot_val(masks->set_mask));
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return new_val;
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}
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static int pageattr_pgd_entry(pgd_t *pgd, unsigned long addr,
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unsigned long next, struct mm_walk *walk)
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{
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pgd_t val = READ_ONCE(*pgd);
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if (pgd_leaf(val)) {
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val = __pgd(set_pageattr_masks(pgd_val(val), walk));
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set_pgd(pgd, val);
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}
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return 0;
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}
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static int pageattr_p4d_entry(p4d_t *p4d, unsigned long addr,
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unsigned long next, struct mm_walk *walk)
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{
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p4d_t val = READ_ONCE(*p4d);
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if (p4d_leaf(val)) {
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val = __p4d(set_pageattr_masks(p4d_val(val), walk));
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set_p4d(p4d, val);
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}
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return 0;
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}
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static int pageattr_pud_entry(pud_t *pud, unsigned long addr,
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unsigned long next, struct mm_walk *walk)
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{
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pud_t val = READ_ONCE(*pud);
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if (pud_leaf(val)) {
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val = __pud(set_pageattr_masks(pud_val(val), walk));
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set_pud(pud, val);
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}
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return 0;
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}
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static int pageattr_pmd_entry(pmd_t *pmd, unsigned long addr,
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unsigned long next, struct mm_walk *walk)
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{
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pmd_t val = READ_ONCE(*pmd);
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if (pmd_leaf(val)) {
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val = __pmd(set_pageattr_masks(pmd_val(val), walk));
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set_pmd(pmd, val);
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}
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return 0;
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}
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static int pageattr_pte_entry(pte_t *pte, unsigned long addr,
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unsigned long next, struct mm_walk *walk)
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{
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pte_t val = READ_ONCE(*pte);
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val = __pte(set_pageattr_masks(pte_val(val), walk));
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set_pte(pte, val);
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return 0;
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}
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static int pageattr_pte_hole(unsigned long addr, unsigned long next,
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int depth, struct mm_walk *walk)
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{
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/* Nothing to do here */
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return 0;
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}
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static const struct mm_walk_ops pageattr_ops = {
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.pgd_entry = pageattr_pgd_entry,
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.p4d_entry = pageattr_p4d_entry,
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.pud_entry = pageattr_pud_entry,
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.pmd_entry = pageattr_pmd_entry,
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.pte_entry = pageattr_pte_entry,
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.pte_hole = pageattr_pte_hole,
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};
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static int __set_memory(unsigned long addr, int numpages, pgprot_t set_mask,
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pgprot_t clear_mask)
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{
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int ret;
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unsigned long start = addr;
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unsigned long end = start + PAGE_SIZE * numpages;
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struct pageattr_masks masks = {
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.set_mask = set_mask,
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.clear_mask = clear_mask
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};
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if (!numpages)
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return 0;
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mmap_write_lock(&init_mm);
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ret = walk_page_range_novma(&init_mm, start, end, &pageattr_ops, NULL,
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&masks);
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mmap_write_unlock(&init_mm);
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flush_tlb_kernel_range(start, end);
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return ret;
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}
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int set_memory_rw_nx(unsigned long addr, int numpages)
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{
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return __set_memory(addr, numpages, __pgprot(_PAGE_READ | _PAGE_WRITE),
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__pgprot(_PAGE_EXEC));
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}
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int set_memory_ro(unsigned long addr, int numpages)
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{
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return __set_memory(addr, numpages, __pgprot(_PAGE_READ),
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__pgprot(_PAGE_WRITE));
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}
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int set_memory_rw(unsigned long addr, int numpages)
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{
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return __set_memory(addr, numpages, __pgprot(_PAGE_READ | _PAGE_WRITE),
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__pgprot(0));
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}
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int set_memory_x(unsigned long addr, int numpages)
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{
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return __set_memory(addr, numpages, __pgprot(_PAGE_EXEC), __pgprot(0));
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}
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int set_memory_nx(unsigned long addr, int numpages)
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{
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return __set_memory(addr, numpages, __pgprot(0), __pgprot(_PAGE_EXEC));
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}
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int set_direct_map_invalid_noflush(struct page *page)
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{
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int ret;
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unsigned long start = (unsigned long)page_address(page);
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unsigned long end = start + PAGE_SIZE;
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struct pageattr_masks masks = {
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.set_mask = __pgprot(0),
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.clear_mask = __pgprot(_PAGE_PRESENT)
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};
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mmap_read_lock(&init_mm);
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ret = walk_page_range(&init_mm, start, end, &pageattr_ops, &masks);
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mmap_read_unlock(&init_mm);
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return ret;
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}
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int set_direct_map_default_noflush(struct page *page)
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{
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int ret;
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unsigned long start = (unsigned long)page_address(page);
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unsigned long end = start + PAGE_SIZE;
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struct pageattr_masks masks = {
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.set_mask = PAGE_KERNEL,
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.clear_mask = __pgprot(0)
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};
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mmap_read_lock(&init_mm);
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ret = walk_page_range(&init_mm, start, end, &pageattr_ops, &masks);
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mmap_read_unlock(&init_mm);
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return ret;
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}
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#ifdef CONFIG_DEBUG_PAGEALLOC
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void __kernel_map_pages(struct page *page, int numpages, int enable)
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{
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if (!debug_pagealloc_enabled())
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return;
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if (enable)
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__set_memory((unsigned long)page_address(page), numpages,
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__pgprot(_PAGE_PRESENT), __pgprot(0));
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else
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__set_memory((unsigned long)page_address(page), numpages,
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__pgprot(0), __pgprot(_PAGE_PRESENT));
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}
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#endif
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bool kernel_page_present(struct page *page)
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{
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unsigned long addr = (unsigned long)page_address(page);
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pgd_t *pgd;
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pud_t *pud;
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p4d_t *p4d;
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pmd_t *pmd;
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pte_t *pte;
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pgd = pgd_offset_k(addr);
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if (!pgd_present(*pgd))
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return false;
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if (pgd_leaf(*pgd))
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return true;
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p4d = p4d_offset(pgd, addr);
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if (!p4d_present(*p4d))
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return false;
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if (p4d_leaf(*p4d))
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return true;
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pud = pud_offset(p4d, addr);
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if (!pud_present(*pud))
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return false;
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if (pud_leaf(*pud))
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return true;
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pmd = pmd_offset(pud, addr);
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if (!pmd_present(*pmd))
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return false;
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if (pmd_leaf(*pmd))
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return true;
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pte = pte_offset_kernel(pmd, addr);
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return pte_present(*pte);
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}
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