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-rw-r--r--arch/xtensa/include/asm/pgtable.h429
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diff --git a/arch/xtensa/include/asm/pgtable.h b/arch/xtensa/include/asm/pgtable.h
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+++ b/arch/xtensa/include/asm/pgtable.h
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+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * include/asm-xtensa/pgtable.h
+ *
+ * Copyright (C) 2001 - 2013 Tensilica Inc.
+ */
+
+#ifndef _XTENSA_PGTABLE_H
+#define _XTENSA_PGTABLE_H
+
+#include <asm/page.h>
+#include <asm/kmem_layout.h>
+#include <asm-generic/pgtable-nopmd.h>
+
+/*
+ * We only use two ring levels, user and kernel space.
+ */
+
+#ifdef CONFIG_MMU
+#define USER_RING 1 /* user ring level */
+#else
+#define USER_RING 0
+#endif
+#define KERNEL_RING 0 /* kernel ring level */
+
+/*
+ * The Xtensa architecture port of Linux has a two-level page table system,
+ * i.e. the logical three-level Linux page table layout is folded.
+ * Each task has the following memory page tables:
+ *
+ * PGD table (page directory), ie. 3rd-level page table:
+ * One page (4 kB) of 1024 (PTRS_PER_PGD) pointers to PTE tables
+ * (Architectures that don't have the PMD folded point to the PMD tables)
+ *
+ * The pointer to the PGD table for a given task can be retrieved from
+ * the task structure (struct task_struct*) t, e.g. current():
+ * (t->mm ? t->mm : t->active_mm)->pgd
+ *
+ * PMD tables (page middle-directory), ie. 2nd-level page tables:
+ * Absent for the Xtensa architecture (folded, PTRS_PER_PMD == 1).
+ *
+ * PTE tables (page table entry), ie. 1st-level page tables:
+ * One page (4 kB) of 1024 (PTRS_PER_PTE) PTEs with a special PTE
+ * invalid_pte_table for absent mappings.
+ *
+ * The individual pages are 4 kB big with special pages for the empty_zero_page.
+ */
+
+#define PGDIR_SHIFT 22
+#define PGDIR_SIZE (1UL << PGDIR_SHIFT)
+#define PGDIR_MASK (~(PGDIR_SIZE-1))
+
+/*
+ * Entries per page directory level: we use two-level, so
+ * we don't really have any PMD directory physically.
+ */
+#define PTRS_PER_PTE 1024
+#define PTRS_PER_PTE_SHIFT 10
+#define PTRS_PER_PGD 1024
+#define USER_PTRS_PER_PGD (TASK_SIZE/PGDIR_SIZE)
+#define FIRST_USER_PGD_NR (FIRST_USER_ADDRESS >> PGDIR_SHIFT)
+
+#ifdef CONFIG_MMU
+/*
+ * Virtual memory area. We keep a distance to other memory regions to be
+ * on the safe side. We also use this area for cache aliasing.
+ */
+#define VMALLOC_START (XCHAL_KSEG_CACHED_VADDR - 0x10000000)
+#define VMALLOC_END (VMALLOC_START + 0x07FEFFFF)
+#define TLBTEMP_BASE_1 (VMALLOC_START + 0x08000000)
+#define TLBTEMP_BASE_2 (TLBTEMP_BASE_1 + DCACHE_WAY_SIZE)
+#if 2 * DCACHE_WAY_SIZE > ICACHE_WAY_SIZE
+#define TLBTEMP_SIZE (2 * DCACHE_WAY_SIZE)
+#else
+#define TLBTEMP_SIZE ICACHE_WAY_SIZE
+#endif
+
+#else
+
+#define VMALLOC_START __XTENSA_UL_CONST(0)
+#define VMALLOC_END __XTENSA_UL_CONST(0xffffffff)
+
+#endif
+
+/*
+ * For the Xtensa architecture, the PTE layout is as follows:
+ *
+ * 31------12 11 10-9 8-6 5-4 3-2 1-0
+ * +-----------------------------------------+
+ * | | Software | HARDWARE |
+ * | PPN | ADW | RI |Attribute|
+ * +-----------------------------------------+
+ * pte_none | MBZ | 01 | 11 | 00 |
+ * +-----------------------------------------+
+ * present | PPN | 0 | 00 | ADW | RI | CA | wx |
+ * +- - - - - - - - - - - - - - - - - - - - -+
+ * (PAGE_NONE)| PPN | 0 | 00 | ADW | 01 | 11 | 11 |
+ * +-----------------------------------------+
+ * swap | index | type | 01 | 11 | e0 |
+ * +-----------------------------------------+
+ *
+ * For T1050 hardware and earlier the layout differs for present and (PAGE_NONE)
+ * +-----------------------------------------+
+ * present | PPN | 0 | 00 | ADW | RI | CA | w1 |
+ * +-----------------------------------------+
+ * (PAGE_NONE)| PPN | 0 | 00 | ADW | 01 | 01 | 00 |
+ * +-----------------------------------------+
+ *
+ * Legend:
+ * PPN Physical Page Number
+ * ADW software: accessed (young) / dirty / writable
+ * RI ring (0=privileged, 1=user, 2 and 3 are unused)
+ * CA cache attribute: 00 bypass, 01 writeback, 10 writethrough
+ * (11 is invalid and used to mark pages that are not present)
+ * e exclusive marker in swap PTEs
+ * w page is writable (hw)
+ * x page is executable (hw)
+ * index swap offset / PAGE_SIZE (bit 11-31: 21 bits -> 8 GB)
+ * (note that the index is always non-zero)
+ * type swap type (5 bits -> 32 types)
+ *
+ * Notes:
+ * - (PROT_NONE) is a special case of 'present' but causes an exception for
+ * any access (read, write, and execute).
+ * - 'multihit-exception' has the highest priority of all MMU exceptions,
+ * so the ring must be set to 'RING_USER' even for 'non-present' pages.
+ * - on older hardware, the exectuable flag was not supported and
+ * used as a 'valid' flag, so it needs to be always set.
+ * - we need to keep track of certain flags in software (dirty and young)
+ * to do this, we use write exceptions and have a separate software w-flag.
+ * - attribute value 1101 (and 1111 on T1050 and earlier) is reserved
+ */
+
+#define _PAGE_ATTRIB_MASK 0xf
+
+#define _PAGE_HW_EXEC (1<<0) /* hardware: page is executable */
+#define _PAGE_HW_WRITE (1<<1) /* hardware: page is writable */
+
+#define _PAGE_CA_BYPASS (0<<2) /* bypass, non-speculative */
+#define _PAGE_CA_WB (1<<2) /* write-back */
+#define _PAGE_CA_WT (2<<2) /* write-through */
+#define _PAGE_CA_MASK (3<<2)
+#define _PAGE_CA_INVALID (3<<2)
+
+/* We use invalid attribute values to distinguish special pte entries */
+#if XCHAL_HW_VERSION_MAJOR < 2000
+#define _PAGE_HW_VALID 0x01 /* older HW needed this bit set */
+#define _PAGE_NONE 0x04
+#else
+#define _PAGE_HW_VALID 0x00
+#define _PAGE_NONE 0x0f
+#endif
+
+#define _PAGE_USER (1<<4) /* user access (ring=1) */
+
+/* Software */
+#define _PAGE_WRITABLE_BIT 6
+#define _PAGE_WRITABLE (1<<6) /* software: page writable */
+#define _PAGE_DIRTY (1<<7) /* software: page dirty */
+#define _PAGE_ACCESSED (1<<8) /* software: page accessed (read) */
+
+/* We borrow bit 1 to store the exclusive marker in swap PTEs. */
+#define _PAGE_SWP_EXCLUSIVE (1<<1)
+
+#ifdef CONFIG_MMU
+
+#define _PAGE_CHG_MASK (PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)
+#define _PAGE_PRESENT (_PAGE_HW_VALID | _PAGE_CA_WB | _PAGE_ACCESSED)
+
+#define PAGE_NONE __pgprot(_PAGE_NONE | _PAGE_USER)
+#define PAGE_COPY __pgprot(_PAGE_PRESENT | _PAGE_USER)
+#define PAGE_COPY_EXEC __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_HW_EXEC)
+#define PAGE_READONLY __pgprot(_PAGE_PRESENT | _PAGE_USER)
+#define PAGE_READONLY_EXEC __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_HW_EXEC)
+#define PAGE_SHARED __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_WRITABLE)
+#define PAGE_SHARED_EXEC \
+ __pgprot(_PAGE_PRESENT | _PAGE_USER | _PAGE_WRITABLE | _PAGE_HW_EXEC)
+#define PAGE_KERNEL __pgprot(_PAGE_PRESENT | _PAGE_HW_WRITE)
+#define PAGE_KERNEL_RO __pgprot(_PAGE_PRESENT)
+#define PAGE_KERNEL_EXEC __pgprot(_PAGE_PRESENT|_PAGE_HW_WRITE|_PAGE_HW_EXEC)
+
+#if (DCACHE_WAY_SIZE > PAGE_SIZE)
+# define _PAGE_DIRECTORY (_PAGE_HW_VALID | _PAGE_ACCESSED | _PAGE_CA_BYPASS)
+#else
+# define _PAGE_DIRECTORY (_PAGE_HW_VALID | _PAGE_ACCESSED | _PAGE_CA_WB)
+#endif
+
+#else /* no mmu */
+
+# define _PAGE_CHG_MASK (PAGE_MASK | _PAGE_ACCESSED | _PAGE_DIRTY)
+# define PAGE_NONE __pgprot(0)
+# define PAGE_SHARED __pgprot(0)
+# define PAGE_COPY __pgprot(0)
+# define PAGE_READONLY __pgprot(0)
+# define PAGE_KERNEL __pgprot(0)
+
+#endif
+
+/*
+ * On certain configurations of Xtensa MMUs (eg. the initial Linux config),
+ * the MMU can't do page protection for execute, and considers that the same as
+ * read. Also, write permissions may imply read permissions.
+ * What follows is the closest we can get by reasonable means..
+ * See linux/mm/mmap.c for protection_map[] array that uses these definitions.
+ */
+#ifndef __ASSEMBLY__
+
+#define pte_ERROR(e) \
+ printk("%s:%d: bad pte %08lx.\n", __FILE__, __LINE__, pte_val(e))
+#define pgd_ERROR(e) \
+ printk("%s:%d: bad pgd entry %08lx.\n", __FILE__, __LINE__, pgd_val(e))
+
+extern unsigned long empty_zero_page[1024];
+
+#define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page))
+
+#ifdef CONFIG_MMU
+extern pgd_t swapper_pg_dir[PAGE_SIZE/sizeof(pgd_t)];
+extern void paging_init(void);
+#else
+# define swapper_pg_dir NULL
+static inline void paging_init(void) { }
+#endif
+
+/*
+ * The pmd contains the kernel virtual address of the pte page.
+ */
+#define pmd_page_vaddr(pmd) ((unsigned long)(pmd_val(pmd) & PAGE_MASK))
+#define pmd_pfn(pmd) (__pa(pmd_val(pmd)) >> PAGE_SHIFT)
+#define pmd_page(pmd) virt_to_page(pmd_val(pmd))
+
+/*
+ * pte status.
+ */
+# define pte_none(pte) (pte_val(pte) == (_PAGE_CA_INVALID | _PAGE_USER))
+#if XCHAL_HW_VERSION_MAJOR < 2000
+# define pte_present(pte) ((pte_val(pte) & _PAGE_CA_MASK) != _PAGE_CA_INVALID)
+#else
+# define pte_present(pte) \
+ (((pte_val(pte) & _PAGE_CA_MASK) != _PAGE_CA_INVALID) \
+ || ((pte_val(pte) & _PAGE_ATTRIB_MASK) == _PAGE_NONE))
+#endif
+#define pte_clear(mm,addr,ptep) \
+ do { update_pte(ptep, __pte(_PAGE_CA_INVALID | _PAGE_USER)); } while (0)
+
+#define pmd_none(pmd) (!pmd_val(pmd))
+#define pmd_present(pmd) (pmd_val(pmd) & PAGE_MASK)
+#define pmd_bad(pmd) (pmd_val(pmd) & ~PAGE_MASK)
+#define pmd_clear(pmdp) do { set_pmd(pmdp, __pmd(0)); } while (0)
+
+static inline int pte_write(pte_t pte) { return pte_val(pte) & _PAGE_WRITABLE; }
+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 pte_t pte_wrprotect(pte_t pte)
+ { pte_val(pte) &= ~(_PAGE_WRITABLE | _PAGE_HW_WRITE); return pte; }
+static inline pte_t pte_mkclean(pte_t pte)
+ { pte_val(pte) &= ~(_PAGE_DIRTY | _PAGE_HW_WRITE); return pte; }
+static inline pte_t pte_mkold(pte_t pte)
+ { pte_val(pte) &= ~_PAGE_ACCESSED; 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; }
+static inline pte_t pte_mkwrite_novma(pte_t pte)
+ { pte_val(pte) |= _PAGE_WRITABLE; return pte; }
+
+#define pgprot_noncached(prot) \
+ ((__pgprot((pgprot_val(prot) & ~_PAGE_CA_MASK) | \
+ _PAGE_CA_BYPASS)))
+
+/*
+ * 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 PFN_PTE_SHIFT PAGE_SHIFT
+#define pte_pfn(pte) (pte_val(pte) >> PAGE_SHIFT)
+#define pte_same(a,b) (pte_val(a) == pte_val(b))
+#define pte_page(x) pfn_to_page(pte_pfn(x))
+#define pfn_pte(pfn, prot) __pte(((pfn) << PAGE_SHIFT) | pgprot_val(prot))
+#define mk_pte(page, prot) pfn_pte(page_to_pfn(page), prot)
+
+static inline pte_t pte_modify(pte_t pte, pgprot_t newprot)
+{
+ return __pte((pte_val(pte) & _PAGE_CHG_MASK) | pgprot_val(newprot));
+}
+
+/*
+ * Certain architectures need to do special things when pte's
+ * within a page table are directly modified. Thus, the following
+ * hook is made available.
+ */
+static inline void update_pte(pte_t *ptep, pte_t pteval)
+{
+ *ptep = pteval;
+#if (DCACHE_WAY_SIZE > PAGE_SIZE) && XCHAL_DCACHE_IS_WRITEBACK
+ __asm__ __volatile__ ("dhwb %0, 0" :: "a" (ptep));
+#endif
+
+}
+
+struct mm_struct;
+
+static inline void set_pte(pte_t *ptep, pte_t pte)
+{
+ update_pte(ptep, pte);
+}
+
+static inline void
+set_pmd(pmd_t *pmdp, pmd_t pmdval)
+{
+ *pmdp = pmdval;
+}
+
+struct vm_area_struct;
+
+static inline int
+ptep_test_and_clear_young(struct vm_area_struct *vma, unsigned long addr,
+ pte_t *ptep)
+{
+ pte_t pte = *ptep;
+ if (!pte_young(pte))
+ return 0;
+ update_pte(ptep, pte_mkold(pte));
+ return 1;
+}
+
+static inline pte_t
+ptep_get_and_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
+{
+ pte_t pte = *ptep;
+ pte_clear(mm, addr, ptep);
+ return pte;
+}
+
+static inline void
+ptep_set_wrprotect(struct mm_struct *mm, unsigned long addr, pte_t *ptep)
+{
+ pte_t pte = *ptep;
+ update_pte(ptep, pte_wrprotect(pte));
+}
+
+/*
+ * Encode/decode swap entries and swap PTEs. Swap PTEs are all PTEs that
+ * are !pte_none() && !pte_present().
+ */
+#define MAX_SWAPFILES_CHECK() BUILD_BUG_ON(MAX_SWAPFILES_SHIFT > 5)
+
+#define __swp_type(entry) (((entry).val >> 6) & 0x1f)
+#define __swp_offset(entry) ((entry).val >> 11)
+#define __swp_entry(type,offs) \
+ ((swp_entry_t){(((type) & 0x1f) << 6) | ((offs) << 11) | \
+ _PAGE_CA_INVALID | _PAGE_USER})
+#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
+#define __swp_entry_to_pte(x) ((pte_t) { (x).val })
+
+static inline int pte_swp_exclusive(pte_t pte)
+{
+ return pte_val(pte) & _PAGE_SWP_EXCLUSIVE;
+}
+
+static inline pte_t pte_swp_mkexclusive(pte_t pte)
+{
+ pte_val(pte) |= _PAGE_SWP_EXCLUSIVE;
+ return pte;
+}
+
+static inline pte_t pte_swp_clear_exclusive(pte_t pte)
+{
+ pte_val(pte) &= ~_PAGE_SWP_EXCLUSIVE;
+ return pte;
+}
+
+#endif /* !defined (__ASSEMBLY__) */
+
+
+#ifdef __ASSEMBLY__
+
+/* Assembly macro _PGD_INDEX is the same as C pgd_index(unsigned long),
+ * _PGD_OFFSET as C pgd_offset(struct mm_struct*, unsigned long),
+ * _PMD_OFFSET as C pmd_offset(pgd_t*, unsigned long)
+ * _PTE_OFFSET as C pte_offset(pmd_t*, unsigned long)
+ *
+ * Note: We require an additional temporary register which can be the same as
+ * the register that holds the address.
+ *
+ * ((pte_t*) ((unsigned long)(pmd_val(*pmd) & PAGE_MASK)) + pte_index(addr))
+ *
+ */
+#define _PGD_INDEX(rt,rs) extui rt, rs, PGDIR_SHIFT, 32-PGDIR_SHIFT
+#define _PTE_INDEX(rt,rs) extui rt, rs, PAGE_SHIFT, PTRS_PER_PTE_SHIFT
+
+#define _PGD_OFFSET(mm,adr,tmp) l32i mm, mm, MM_PGD; \
+ _PGD_INDEX(tmp, adr); \
+ addx4 mm, tmp, mm
+
+#define _PTE_OFFSET(pmd,adr,tmp) _PTE_INDEX(tmp, adr); \
+ srli pmd, pmd, PAGE_SHIFT; \
+ slli pmd, pmd, PAGE_SHIFT; \
+ addx4 pmd, tmp, pmd
+
+#else
+
+struct vm_fault;
+void update_mmu_cache_range(struct vm_fault *vmf, struct vm_area_struct *vma,
+ unsigned long address, pte_t *ptep, unsigned int nr);
+#define update_mmu_cache(vma, address, ptep) \
+ update_mmu_cache_range(NULL, vma, address, ptep, 1)
+
+typedef pte_t *pte_addr_t;
+
+void update_mmu_tlb(struct vm_area_struct *vma,
+ unsigned long address, pte_t *ptep);
+#define __HAVE_ARCH_UPDATE_MMU_TLB
+
+#endif /* !defined (__ASSEMBLY__) */
+
+#define __HAVE_ARCH_PTEP_TEST_AND_CLEAR_YOUNG
+#define __HAVE_ARCH_PTEP_GET_AND_CLEAR
+#define __HAVE_ARCH_PTEP_SET_WRPROTECT
+#define __HAVE_ARCH_PTEP_MKDIRTY
+#define __HAVE_ARCH_PTE_SAME
+/* We provide our own get_unmapped_area to cope with
+ * SHM area cache aliasing for userland.
+ */
+#define HAVE_ARCH_UNMAPPED_AREA
+
+#endif /* _XTENSA_PGTABLE_H */
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