1 files changed, 575 insertions, 0 deletions
diff --git a/arch/loongarch/include/asm/pgtable.h b/arch/loongarch/include/asm/pgtable.h
new file mode 100644
index 000000000..f991e678c
--- /dev/null
+++ b/arch/loongarch/include/asm/pgtable.h
@@ -0,0 +1,575 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
+ *
+ * Derived from MIPS:
+ * Copyright (C) 1994, 95, 96, 97, 98, 99, 2000, 2003 Ralf Baechle
+ * Copyright (C) 1999, 2000, 2001 Silicon Graphics, Inc.
+ */
+#ifndef _ASM_PGTABLE_H
+#define _ASM_PGTABLE_H
+
+#include <linux/compiler.h>
+#include <asm/addrspace.h>
+#include <asm/pgtable-bits.h>
+
+#if CONFIG_PGTABLE_LEVELS == 2
+#include <asm-generic/pgtable-nopmd.h>
+#elif CONFIG_PGTABLE_LEVELS == 3
+#include <asm-generic/pgtable-nopud.h>
+#else
+#include <asm-generic/pgtable-nop4d.h>
+#endif
+
+#if CONFIG_PGTABLE_LEVELS == 2
+#define PGDIR_SHIFT	(PAGE_SHIFT + (PAGE_SHIFT - 3))
+#elif CONFIG_PGTABLE_LEVELS == 3
+#define PMD_SHIFT	(PAGE_SHIFT + (PAGE_SHIFT - 3))
+#define PMD_SIZE	(1UL << PMD_SHIFT)
+#define PMD_MASK	(~(PMD_SIZE-1))
+#define PGDIR_SHIFT	(PMD_SHIFT + (PAGE_SHIFT - 3))
+#elif CONFIG_PGTABLE_LEVELS == 4
+#define PMD_SHIFT	(PAGE_SHIFT + (PAGE_SHIFT - 3))
+#define PMD_SIZE	(1UL << PMD_SHIFT)
+#define PMD_MASK	(~(PMD_SIZE-1))
+#define PUD_SHIFT	(PMD_SHIFT + (PAGE_SHIFT - 3))
+#define PUD_SIZE	(1UL << PUD_SHIFT)
+#define PUD_MASK	(~(PUD_SIZE-1))
+#define PGDIR_SHIFT	(PUD_SHIFT + (PAGE_SHIFT - 3))
+#endif
+
+#define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
+#define PGDIR_MASK	(~(PGDIR_SIZE-1))
+
+#define VA_BITS		(PGDIR_SHIFT + (PAGE_SHIFT - 3))
+
+#define PTRS_PER_PGD	(PAGE_SIZE >> 3)
+#if CONFIG_PGTABLE_LEVELS > 3
+#define PTRS_PER_PUD	(PAGE_SIZE >> 3)
+#endif
+#if CONFIG_PGTABLE_LEVELS > 2
+#define PTRS_PER_PMD	(PAGE_SIZE >> 3)
+#endif
+#define PTRS_PER_PTE	(PAGE_SIZE >> 3)
+
+#define USER_PTRS_PER_PGD       ((TASK_SIZE64 / PGDIR_SIZE)?(TASK_SIZE64 / PGDIR_SIZE):1)
+
+#ifndef __ASSEMBLY__
+
+#include <linux/mm_types.h>
+#include <linux/mmzone.h>
+#include <asm/fixmap.h>
+
+struct mm_struct;
+struct vm_area_struct;
+
+/*
+ * ZERO_PAGE is a global shared page that is always zero; used
+ * for zero-mapped memory areas etc..
+ */
+
+extern unsigned long empty_zero_page;
+extern unsigned long zero_page_mask;
+
+#define ZERO_PAGE(vaddr) \
+	(virt_to_page((void *)(empty_zero_page + (((unsigned long)(vaddr)) & zero_page_mask))))
+#define __HAVE_COLOR_ZERO_PAGE
+
+/*
+ * TLB refill handlers may also map the vmalloc area into xkvrange.
+ * Avoid the first couple of pages so NULL pointer dereferences will
+ * still reliably trap.
+ */
+#define MODULES_VADDR	(vm_map_base + PCI_IOSIZE + (2 * PAGE_SIZE))
+#define MODULES_END	(MODULES_VADDR + SZ_256M)
+
+#define VMALLOC_START	MODULES_END
+#define VMALLOC_END	\
+	(vm_map_base +	\
+	 min(PTRS_PER_PGD * PTRS_PER_PUD * PTRS_PER_PMD * PTRS_PER_PTE * PAGE_SIZE, (1UL << cpu_vabits)) - PMD_SIZE)
+
+#define pte_ERROR(e) \
+	pr_err("%s:%d: bad pte %016lx.\n", __FILE__, __LINE__, pte_val(e))
+#ifndef __PAGETABLE_PMD_FOLDED
+#define pmd_ERROR(e) \
+	pr_err("%s:%d: bad pmd %016lx.\n", __FILE__, __LINE__, pmd_val(e))
+#endif
+#ifndef __PAGETABLE_PUD_FOLDED
+#define pud_ERROR(e) \
+	pr_err("%s:%d: bad pud %016lx.\n", __FILE__, __LINE__, pud_val(e))
+#endif
+#define pgd_ERROR(e) \
+	pr_err("%s:%d: bad pgd %016lx.\n", __FILE__, __LINE__, pgd_val(e))
+
+extern pte_t invalid_pte_table[PTRS_PER_PTE];
+
+#ifndef __PAGETABLE_PUD_FOLDED
+
+typedef struct { unsigned long pud; } pud_t;
+#define pud_val(x)	((x).pud)
+#define __pud(x)	((pud_t) { (x) })
+
+extern pud_t invalid_pud_table[PTRS_PER_PUD];
+
+/*
+ * Empty pgd/p4d entries point to the invalid_pud_table.
+ */
+static inline int p4d_none(p4d_t p4d)
+{
+	return p4d_val(p4d) == (unsigned long)invalid_pud_table;
+}
+
+static inline int p4d_bad(p4d_t p4d)
+{
+	return p4d_val(p4d) & ~PAGE_MASK;
+}
+
+static inline int p4d_present(p4d_t p4d)
+{
+	return p4d_val(p4d) != (unsigned long)invalid_pud_table;
+}
+
+static inline void p4d_clear(p4d_t *p4dp)
+{
+	p4d_val(*p4dp) = (unsigned long)invalid_pud_table;
+}
+
+static inline pud_t *p4d_pgtable(p4d_t p4d)
+{
+	return (pud_t *)p4d_val(p4d);
+}
+
+static inline void set_p4d(p4d_t *p4d, p4d_t p4dval)
+{
+	*p4d = p4dval;
+}
+
+#define p4d_phys(p4d)		PHYSADDR(p4d_val(p4d))
+#define p4d_page(p4d)		(pfn_to_page(p4d_phys(p4d) >> PAGE_SHIFT))
+
+#endif
+
+#ifndef __PAGETABLE_PMD_FOLDED
+
+typedef struct { unsigned long pmd; } pmd_t;
+#define pmd_val(x)	((x).pmd)
+#define __pmd(x)	((pmd_t) { (x) })
+
+extern pmd_t invalid_pmd_table[PTRS_PER_PMD];
+
+/*
+ * Empty pud entries point to the invalid_pmd_table.
+ */
+static inline int pud_none(pud_t pud)
+{
+	return pud_val(pud) == (unsigned long)invalid_pmd_table;
+}
+
+static inline int pud_bad(pud_t pud)
+{
+	return pud_val(pud) & ~PAGE_MASK;
+}
+
+static inline int pud_present(pud_t pud)
+{
+	return pud_val(pud) != (unsigned long)invalid_pmd_table;
+}
+
+static inline void pud_clear(pud_t *pudp)
+{
+	pud_val(*pudp) = ((unsigned long)invalid_pmd_table);
+}
+
+static inline pmd_t *pud_pgtable(pud_t pud)
+{
+	return (pmd_t *)pud_val(pud);
+}
+
+#define set_pud(pudptr, pudval) do { *(pudptr) = (pudval); } while (0)
+
+#define pud_phys(pud)		PHYSADDR(pud_val(pud))
+#define pud_page(pud)		(pfn_to_page(pud_phys(pud) >> PAGE_SHIFT))
+
+#endif
+
+/*
+ * Empty pmd entries point to the invalid_pte_table.
+ */
+static inline int pmd_none(pmd_t pmd)
+{
+	return pmd_val(pmd) == (unsigned long)invalid_pte_table;
+}
+
+static inline int pmd_bad(pmd_t pmd)
+{
+	return (pmd_val(pmd) & ~PAGE_MASK);
+}
+
+static inline int pmd_present(pmd_t pmd)
+{
+	if (unlikely(pmd_val(pmd) & _PAGE_HUGE))
+		return !!(pmd_val(pmd) & (_PAGE_PRESENT | _PAGE_PROTNONE | _PAGE_PRESENT_INVALID));
+
+	return pmd_val(pmd) != (unsigned long)invalid_pte_table;
+}
+
+static inline void pmd_clear(pmd_t *pmdp)
+{
+	pmd_val(*pmdp) = ((unsigned long)invalid_pte_table);
+}
+
+#define set_pmd(pmdptr, pmdval) do { *(pmdptr) = (pmdval); } while (0)
+
+#define pmd_phys(pmd)		PHYSADDR(pmd_val(pmd))
+
+#ifndef CONFIG_TRANSPARENT_HUGEPAGE
+#define pmd_page(pmd)		(pfn_to_page(pmd_phys(pmd) >> PAGE_SHIFT))
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE  */
+
+#define pmd_page_vaddr(pmd)	pmd_val(pmd)
+
+extern pmd_t mk_pmd(struct page *page, pgprot_t prot);
+extern void set_pmd_at(struct mm_struct *mm, unsigned long addr, pmd_t *pmdp, pmd_t pmd);
+
+#define pte_page(x)		pfn_to_page(pte_pfn(x))
+#define pte_pfn(x)		((unsigned long)(((x).pte & _PFN_MASK) >> _PFN_SHIFT))
+#define pfn_pte(pfn, prot)	__pte(((pfn) << _PFN_SHIFT) | pgprot_val(prot))
+#define pfn_pmd(pfn, prot)	__pmd(((pfn) << _PFN_SHIFT) | pgprot_val(prot))
+
+/*
+ * Initialize a new pgd / pmd table with invalid pointers.
+ */
+extern void pgd_init(unsigned long page);
+extern void pud_init(unsigned long page, unsigned long pagetable);
+extern void pmd_init(unsigned long page, unsigned long pagetable);
+
+/*
+ * Non-present pages:  high 40 bits are offset, next 8 bits type,
+ * low 16 bits zero.
+ */
+static inline pte_t mk_swap_pte(unsigned long type, unsigned long offset)
+{ pte_t pte; pte_val(pte) = (type << 16) | (offset << 24); return pte; }
+
+#define __swp_type(x)		(((x).val >> 16) & 0xff)
+#define __swp_offset(x)		((x).val >> 24)
+#define __swp_entry(type, offset) ((swp_entry_t) { pte_val(mk_swap_pte((type), (offset))) })
+#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
+#define __swp_entry_to_pte(x)	((pte_t) { (x).val })
+#define __pmd_to_swp_entry(pmd) ((swp_entry_t) { pmd_val(pmd) })
+#define __swp_entry_to_pmd(x)	((pmd_t) { (x).val | _PAGE_HUGE })
+
+extern void paging_init(void);
+
+#define pte_none(pte)		(!(pte_val(pte) & ~_PAGE_GLOBAL))
+#define pte_present(pte)	(pte_val(pte) & (_PAGE_PRESENT | _PAGE_PROTNONE))
+#define pte_no_exec(pte)	(pte_val(pte) & _PAGE_NO_EXEC)
+
+static inline void set_pte(pte_t *ptep, pte_t pteval)
+{
+	*ptep = pteval;
+	if (pte_val(pteval) & _PAGE_GLOBAL) {
+		pte_t *buddy = ptep_buddy(ptep);
+		/*
+		 * Make sure the buddy is global too (if it's !none,
+		 * it better already be global)
+		 */
+#ifdef CONFIG_SMP
+		/*
+		 * For SMP, multiple CPUs can race, so we need to do
+		 * this atomically.
+		 */
+		unsigned long page_global = _PAGE_GLOBAL;
+		unsigned long tmp;
+
+		__asm__ __volatile__ (
+		"1:"	__LL	"%[tmp], %[buddy]		\n"
+		"	bnez	%[tmp], 2f			\n"
+		"	 or	%[tmp], %[tmp], %[global]	\n"
+			__SC	"%[tmp], %[buddy]		\n"
+		"	beqz	%[tmp], 1b			\n"
+		"	nop					\n"
+		"2:						\n"
+		__WEAK_LLSC_MB
+		: [buddy] "+m" (buddy->pte), [tmp] "=&r" (tmp)
+		: [global] "r" (page_global));
+#else /* !CONFIG_SMP */
+		if (pte_none(*buddy))
+			pte_val(*buddy) = pte_val(*buddy) | _PAGE_GLOBAL;
+#endif /* CONFIG_SMP */
+	}
+}
+
+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)
+{
+	/* Preserve global status for the pair */
+	if (pte_val(*ptep_buddy(ptep)) & _PAGE_GLOBAL)
+		set_pte_at(mm, addr, ptep, __pte(_PAGE_GLOBAL));
+	else
+		set_pte_at(mm, addr, ptep, __pte(0));
+}
+
+#define PGD_T_LOG2	(__builtin_ffs(sizeof(pgd_t)) - 1)
+#define PMD_T_LOG2	(__builtin_ffs(sizeof(pmd_t)) - 1)
+#define PTE_T_LOG2	(__builtin_ffs(sizeof(pte_t)) - 1)
+
+extern pgd_t swapper_pg_dir[];
+extern pgd_t invalid_pg_dir[];
+
+/*
+ * The following only work if pte_present() is true.
+ * Undefined behaviour if not..
+ */
+static inline int pte_write(pte_t pte)	{ return pte_val(pte) & _PAGE_WRITE; }
+static inline int pte_young(pte_t pte)	{ return pte_val(pte) & _PAGE_ACCESSED; }
+static inline int pte_dirty(pte_t pte)	{ return pte_val(pte) & _PAGE_MODIFIED; }
+
+static inline pte_t pte_mkold(pte_t pte)
+{
+	pte_val(pte) &= ~_PAGE_ACCESSED;
+	return pte;
+}
+
+static inline pte_t pte_mkyoung(pte_t pte)
+{
+	pte_val(pte) |= _PAGE_ACCESSED;
+	return pte;
+}
+
+static inline pte_t pte_mkclean(pte_t pte)
+{
+	pte_val(pte) &= ~(_PAGE_DIRTY | _PAGE_MODIFIED);
+	return pte;
+}
+
+static inline pte_t pte_mkdirty(pte_t pte)
+{
+	pte_val(pte) |= _PAGE_MODIFIED;
+	if (pte_val(pte) & _PAGE_WRITE)
+		pte_val(pte) |= _PAGE_DIRTY;
+	return pte;
+}
+
+static inline pte_t pte_mkwrite(pte_t pte)
+{
+	pte_val(pte) |= _PAGE_WRITE;
+	if (pte_val(pte) & _PAGE_MODIFIED)
+		pte_val(pte) |= _PAGE_DIRTY;
+	return pte;
+}
+
+static inline pte_t pte_wrprotect(pte_t pte)
+{
+	pte_val(pte) &= ~(_PAGE_WRITE | _PAGE_DIRTY);
+	return pte;
+}
+
+static inline int pte_huge(pte_t pte)	{ return pte_val(pte) & _PAGE_HUGE; }
+
+static inline pte_t pte_mkhuge(pte_t pte)
+{
+	pte_val(pte) |= _PAGE_HUGE;
+	return pte;
+}
+
+#if defined(CONFIG_ARCH_HAS_PTE_SPECIAL)
+static inline int pte_special(pte_t pte)	{ return pte_val(pte) & _PAGE_SPECIAL; }
+static inline pte_t pte_mkspecial(pte_t pte)	{ pte_val(pte) |= _PAGE_SPECIAL; return pte; }
+#endif /* CONFIG_ARCH_HAS_PTE_SPECIAL */
+
+#define pte_accessible pte_accessible
+static inline unsigned long pte_accessible(struct mm_struct *mm, pte_t a)
+{
+	if (pte_val(a) & _PAGE_PRESENT)
+		return true;
+
+	if ((pte_val(a) & _PAGE_PROTNONE) &&
+			atomic_read(&mm->tlb_flush_pending))
+		return true;
+
+	return false;
+}
+
+/*
+ * Conversion functions: convert a page and protection to a page entry,
+ * and a page entry and page directory to the page they refer to.
+ */
+#define mk_pte(page, pgprot)	pfn_pte(page_to_pfn(page), (pgprot))
+
+static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
+{
+	return __pte((pte_val(pte) & _PAGE_CHG_MASK) |
+		     (pgprot_val(newprot) & ~_PAGE_CHG_MASK));
+}
+
+extern void __update_tlb(struct vm_area_struct *vma,
+			unsigned long address, pte_t *ptep);
+
+static inline void update_mmu_cache(struct vm_area_struct *vma,
+			unsigned long address, pte_t *ptep)
+{
+	__update_tlb(vma, address, ptep);
+}
+
+#define __HAVE_ARCH_UPDATE_MMU_TLB
+#define update_mmu_tlb	update_mmu_cache
+
+static inline void update_mmu_cache_pmd(struct vm_area_struct *vma,
+			unsigned long address, pmd_t *pmdp)
+{
+	__update_tlb(vma, address, (pte_t *)pmdp);
+}
+
+#define kern_addr_valid(addr)	(1)
+
+static inline unsigned long pmd_pfn(pmd_t pmd)
+{
+	return (pmd_val(pmd) & _PFN_MASK) >> _PFN_SHIFT;
+}
+
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+
+/* We don't have hardware dirty/accessed bits, generic_pmdp_establish is fine.*/
+#define pmdp_establish generic_pmdp_establish
+
+static inline int pmd_trans_huge(pmd_t pmd)
+{
+	return !!(pmd_val(pmd) & _PAGE_HUGE) && pmd_present(pmd);
+}
+
+static inline pmd_t pmd_mkhuge(pmd_t pmd)
+{
+	pmd_val(pmd) = (pmd_val(pmd) & ~(_PAGE_GLOBAL)) |
+		((pmd_val(pmd) & _PAGE_GLOBAL) << (_PAGE_HGLOBAL_SHIFT - _PAGE_GLOBAL_SHIFT));
+	pmd_val(pmd) |= _PAGE_HUGE;
+
+	return pmd;
+}
+
+#define pmd_write pmd_write
+static inline int pmd_write(pmd_t pmd)
+{
+	return !!(pmd_val(pmd) & _PAGE_WRITE);
+}
+
+static inline pmd_t pmd_mkwrite(pmd_t pmd)
+{
+	pmd_val(pmd) |= _PAGE_WRITE;
+	if (pmd_val(pmd) & _PAGE_MODIFIED)
+		pmd_val(pmd) |= _PAGE_DIRTY;
+	return pmd;
+}
+
+static inline pmd_t pmd_wrprotect(pmd_t pmd)
+{
+	pmd_val(pmd) &= ~(_PAGE_WRITE | _PAGE_DIRTY);
+	return pmd;
+}
+
+static inline int pmd_dirty(pmd_t pmd)
+{
+	return !!(pmd_val(pmd) & _PAGE_MODIFIED);
+}
+
+static inline pmd_t pmd_mkclean(pmd_t pmd)
+{
+	pmd_val(pmd) &= ~(_PAGE_DIRTY | _PAGE_MODIFIED);
+	return pmd;
+}
+
+static inline pmd_t pmd_mkdirty(pmd_t pmd)
+{
+	pmd_val(pmd) |= _PAGE_MODIFIED;
+	if (pmd_val(pmd) & _PAGE_WRITE)
+		pmd_val(pmd) |= _PAGE_DIRTY;
+	return pmd;
+}
+
+#define pmd_young pmd_young
+static inline int pmd_young(pmd_t pmd)
+{
+	return !!(pmd_val(pmd) & _PAGE_ACCESSED);
+}
+
+static inline pmd_t pmd_mkold(pmd_t pmd)
+{
+	pmd_val(pmd) &= ~_PAGE_ACCESSED;
+	return pmd;
+}
+
+static inline pmd_t pmd_mkyoung(pmd_t pmd)
+{
+	pmd_val(pmd) |= _PAGE_ACCESSED;
+	return pmd;
+}
+
+static inline struct page *pmd_page(pmd_t pmd)
+{
+	if (pmd_trans_huge(pmd))
+		return pfn_to_page(pmd_pfn(pmd));
+
+	return pfn_to_page(pmd_phys(pmd) >> PAGE_SHIFT);
+}
+
+static inline pmd_t pmd_modify(pmd_t pmd, pgprot_t newprot)
+{
+	pmd_val(pmd) = (pmd_val(pmd) & _HPAGE_CHG_MASK) |
+				(pgprot_val(newprot) & ~_HPAGE_CHG_MASK);
+	return pmd;
+}
+
+static inline pmd_t pmd_mkinvalid(pmd_t pmd)
+{
+	pmd_val(pmd) |= _PAGE_PRESENT_INVALID;
+	pmd_val(pmd) &= ~(_PAGE_PRESENT | _PAGE_VALID | _PAGE_DIRTY | _PAGE_PROTNONE);
+
+	return pmd;
+}
+
+/*
+ * The generic version pmdp_huge_get_and_clear uses a version of pmd_clear() with a
+ * different prototype.
+ */
+#define __HAVE_ARCH_PMDP_HUGE_GET_AND_CLEAR
+static inline pmd_t pmdp_huge_get_and_clear(struct mm_struct *mm,
+					    unsigned long address, pmd_t *pmdp)
+{
+	pmd_t old = *pmdp;
+
+	pmd_clear(pmdp);
+
+	return old;
+}
+
+#endif /* CONFIG_TRANSPARENT_HUGEPAGE */
+
+#ifdef CONFIG_NUMA_BALANCING
+static inline long pte_protnone(pte_t pte)
+{
+	return (pte_val(pte) & _PAGE_PROTNONE);
+}
+
+static inline long pmd_protnone(pmd_t pmd)
+{
+	return (pmd_val(pmd) & _PAGE_PROTNONE);
+}
+#endif /* CONFIG_NUMA_BALANCING */
+
+#define pmd_leaf(pmd)		((pmd_val(pmd) & _PAGE_HUGE) != 0)
+#define pud_leaf(pud)		((pud_val(pud) & _PAGE_HUGE) != 0)
+
+/*
+ * We provide our own get_unmapped area to cope with the virtual aliasing
+ * constraints placed on us by the cache architecture.
+ */
+#define HAVE_ARCH_UNMAPPED_AREA
+#define HAVE_ARCH_UNMAPPED_AREA_TOPDOWN
+
+#endif /* !__ASSEMBLY__ */
+
+#endif /* _ASM_PGTABLE_H */