arch/sparc/include/asm/pgtsrmmu.h

   1 /* SPDX-License-Identifier: GPL-2.0 */
   2 /*
   3  * pgtsrmmu.h:  SRMMU page table defines and code.
   4  *
   5  * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu)
   6  */
   7
   8 #ifndef _SPARC_PGTSRMMU_H
   9 #define _SPARC_PGTSRMMU_H
  10
  11 #include <asm/page.h>
  12
  13 #ifdef __ASSEMBLY__
  14 #include <asm/thread_info.h>    /* TI_UWINMASK for WINDOW_FLUSH */
  15 #endif
  16
  17 /* Number of contexts is implementation-dependent; 64k is the most we support */
  18 #define SRMMU_MAX_CONTEXTS      65536
  19
  20 /* PMD_SHIFT determines the size of the area a second-level page table entry can map */
  21 #define SRMMU_REAL_PMD_SHIFT            18
  22 #define SRMMU_REAL_PMD_SIZE             (1UL << SRMMU_REAL_PMD_SHIFT)
  23 #define SRMMU_REAL_PMD_MASK             (~(SRMMU_REAL_PMD_SIZE-1))
  24 #define SRMMU_REAL_PMD_ALIGN(__addr)    (((__addr)+SRMMU_REAL_PMD_SIZE-1)&SRMMU_REAL_PMD_MASK)
  25
  26 /* PGDIR_SHIFT determines what a third-level page table entry can map */
  27 #define SRMMU_PGDIR_SHIFT       24
  28 #define SRMMU_PGDIR_SIZE        (1UL << SRMMU_PGDIR_SHIFT)
  29 #define SRMMU_PGDIR_MASK        (~(SRMMU_PGDIR_SIZE-1))
  30 #define SRMMU_PGDIR_ALIGN(addr) (((addr)+SRMMU_PGDIR_SIZE-1)&SRMMU_PGDIR_MASK)
  31
  32 #define SRMMU_REAL_PTRS_PER_PTE 64
  33 #define SRMMU_REAL_PTRS_PER_PMD 64
  34 #define SRMMU_PTRS_PER_PGD      256
  35
  36 #define SRMMU_REAL_PTE_TABLE_SIZE       (SRMMU_REAL_PTRS_PER_PTE*4)
  37 #define SRMMU_PMD_TABLE_SIZE            (SRMMU_REAL_PTRS_PER_PMD*4)
  38 #define SRMMU_PGD_TABLE_SIZE            (SRMMU_PTRS_PER_PGD*4)
  39
  40 /*
  41  * To support pagetables in highmem, Linux introduces APIs which
  42  * return struct page* and generally manipulate page tables when
  43  * they are not mapped into kernel space. Our hardware page tables
  44  * are smaller than pages. We lump hardware tabes into big, page sized
  45  * software tables.
  46  *
  47  * PMD_SHIFT determines the size of the area a second-level page table entry
  48  * can map, and our pmd_t is 16 times larger than normal.  The values which
  49  * were once defined here are now generic for 4c and srmmu, so they're
  50  * found in pgtable.h.
  51  */
  52 #define SRMMU_PTRS_PER_PMD      4
  53
  54 /* Definition of the values in the ET field of PTD's and PTE's */
  55 #define SRMMU_ET_MASK         0x3
  56 #define SRMMU_ET_INVALID      0x0
  57 #define SRMMU_ET_PTD          0x1
  58 #define SRMMU_ET_PTE          0x2
  59 #define SRMMU_ET_REPTE        0x3 /* AIEEE, SuperSparc II reverse endian page! */
  60
  61 /* Physical page extraction from PTP's and PTE's. */
  62 #define SRMMU_CTX_PMASK    0xfffffff0
  63 #define SRMMU_PTD_PMASK    0xfffffff0
  64 #define SRMMU_PTE_PMASK    0xffffff00
  65
  66 /* The pte non-page bits.  Some notes:
  67  * 1) cache, dirty, valid, and ref are frobbable
  68  *    for both supervisor and user pages.
  69  * 2) exec and write will only give the desired effect
  70  *    on user pages
  71  * 3) use priv and priv_readonly for changing the
  72  *    characteristics of supervisor ptes
  73  */
  74 #define SRMMU_CACHE        0x80
  75 #define SRMMU_DIRTY        0x40
  76 #define SRMMU_REF          0x20
  77 #define SRMMU_NOREAD       0x10
  78 #define SRMMU_EXEC         0x08
  79 #define SRMMU_WRITE        0x04
  80 #define SRMMU_VALID        0x02 /* SRMMU_ET_PTE */
  81 #define SRMMU_PRIV         0x1c
  82 #define SRMMU_PRIV_RDONLY  0x18
  83
  84 #define SRMMU_CHG_MASK    (0xffffff00 | SRMMU_REF | SRMMU_DIRTY)
  85
  86 /* SRMMU swap entry encoding
  87  *
  88  * We use 5 bits for the type and 19 for the offset.  This gives us
  89  * 32 swapfiles of 4GB each.  Encoding looks like:
  90  *
  91  * oooooooooooooooooootttttRRRRRRRR
  92  * fedcba9876543210fedcba9876543210
  93  *
  94  * The bottom 7 bits are reserved for protection and status bits, especially
  95  * PRESENT.
  96  */
  97 #define SRMMU_SWP_TYPE_MASK     0x1f
  98 #define SRMMU_SWP_TYPE_SHIFT    7
  99 #define SRMMU_SWP_OFF_MASK      0xfffff
 100 #define SRMMU_SWP_OFF_SHIFT     (SRMMU_SWP_TYPE_SHIFT + 5)
 101
 102 /* Some day I will implement true fine grained access bits for
 103  * user pages because the SRMMU gives us the capabilities to
 104  * enforce all the protection levels that vma's can have.
 105  * XXX But for now...
 106  */
 107 #define SRMMU_PAGE_NONE    __pgprot(SRMMU_CACHE | \
 108                                     SRMMU_PRIV | SRMMU_REF)
 109 #define SRMMU_PAGE_SHARED  __pgprot(SRMMU_VALID | SRMMU_CACHE | \
 110                                     SRMMU_EXEC | SRMMU_WRITE | SRMMU_REF)
 111 #define SRMMU_PAGE_COPY    __pgprot(SRMMU_VALID | SRMMU_CACHE | \
 112                                     SRMMU_EXEC | SRMMU_REF)
 113 #define SRMMU_PAGE_RDONLY  __pgprot(SRMMU_VALID | SRMMU_CACHE | \
 114                                     SRMMU_EXEC | SRMMU_REF)
 115 #define SRMMU_PAGE_KERNEL  __pgprot(SRMMU_VALID | SRMMU_CACHE | SRMMU_PRIV | \
 116                                     SRMMU_DIRTY | SRMMU_REF)
 117
 118 /* SRMMU Register addresses in ASI 0x4.  These are valid for all
 119  * current SRMMU implementations that exist.
 120  */
 121 #define SRMMU_CTRL_REG           0x00000000
 122 #define SRMMU_CTXTBL_PTR         0x00000100
 123 #define SRMMU_CTX_REG            0x00000200
 124 #define SRMMU_FAULT_STATUS       0x00000300
 125 #define SRMMU_FAULT_ADDR         0x00000400
 126
 127 #define WINDOW_FLUSH(tmp1, tmp2)                                        \
 128         mov     0, tmp1;                                                \
 129 98:     ld      [%g6 + TI_UWINMASK], tmp2;                              \
 130         orcc    %g0, tmp2, %g0;                                         \
 131         add     tmp1, 1, tmp1;                                          \
 132         bne     98b;                                                    \
 133          save   %sp, -64, %sp;                                          \
 134 99:     subcc   tmp1, 1, tmp1;                                          \
 135         bne     99b;                                                    \
 136          restore %g0, %g0, %g0;
 137
 138 #ifndef __ASSEMBLY__
 139 extern unsigned long last_valid_pfn;
 140
 141 /* This makes sense. Honest it does - Anton */
 142 /* XXX Yes but it's ugly as sin.  FIXME. -KMW */
 143 extern void *srmmu_nocache_pool;
 144 #define __nocache_pa(VADDR) (((unsigned long)VADDR) - SRMMU_NOCACHE_VADDR + __pa((unsigned long)srmmu_nocache_pool))
 145 #define __nocache_va(PADDR) (__va((unsigned long)PADDR) - (unsigned long)srmmu_nocache_pool + SRMMU_NOCACHE_VADDR)
 146 #define __nocache_fix(VADDR) __va(__nocache_pa(VADDR))
 147
 148 /* Accessing the MMU control register. */
 149 unsigned int srmmu_get_mmureg(void);
 150 void srmmu_set_mmureg(unsigned long regval);
 151 void srmmu_set_ctable_ptr(unsigned long paddr);
 152 void srmmu_set_context(int context);
 153 int srmmu_get_context(void);
 154 unsigned int srmmu_get_fstatus(void);
 155 unsigned int srmmu_get_faddr(void);
 156
 157 /* This is guaranteed on all SRMMU's. */
 158 static inline void srmmu_flush_whole_tlb(void)
 159 {
 160         __asm__ __volatile__("sta %%g0, [%0] %1\n\t": :
 161                              "r" (0x400),        /* Flush entire TLB!! */
 162                              "i" (ASI_M_FLUSH_PROBE) : "memory");
 163
 164 }
 165
 166 static inline int
 167 srmmu_get_pte (unsigned long addr)
 168 {
 169         register unsigned long entry;
 170
 171         __asm__ __volatile__("\n\tlda [%1] %2,%0\n\t" :
 172                                 "=r" (entry):
 173                                 "r" ((addr & 0xfffff000) | 0x400), "i" (ASI_M_FLUSH_PROBE));
 174         return entry;
 175 }
 176
 177 #endif /* !(__ASSEMBLY__) */
 178
 179 #endif /* !(_SPARC_PGTSRMMU_H) */