xref: /openbmc/linux/arch/m68k/include/asm/pgtable_mm.h (revision ecba1060)
1 #ifndef _M68K_PGTABLE_H
2 #define _M68K_PGTABLE_H
3 
4 #include <asm-generic/4level-fixup.h>
5 
6 #include <asm/setup.h>
7 
8 #ifndef __ASSEMBLY__
9 #include <asm/processor.h>
10 #include <linux/sched.h>
11 #include <linux/threads.h>
12 
13 /*
14  * This file contains the functions and defines necessary to modify and use
15  * the m68k page table tree.
16  */
17 
18 #include <asm/virtconvert.h>
19 
20 /* Certain architectures need to do special things when pte's
21  * within a page table are directly modified.  Thus, the following
22  * hook is made available.
23  */
24 #define set_pte(pteptr, pteval)					\
25 	do{							\
26 		*(pteptr) = (pteval);				\
27 	} while(0)
28 #define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval)
29 
30 
31 /* PMD_SHIFT determines the size of the area a second-level page table can map */
32 #ifdef CONFIG_SUN3
33 #define PMD_SHIFT       17
34 #else
35 #define PMD_SHIFT	22
36 #endif
37 #define PMD_SIZE	(1UL << PMD_SHIFT)
38 #define PMD_MASK	(~(PMD_SIZE-1))
39 
40 /* PGDIR_SHIFT determines what a third-level page table entry can map */
41 #ifdef CONFIG_SUN3
42 #define PGDIR_SHIFT     17
43 #else
44 #define PGDIR_SHIFT	25
45 #endif
46 #define PGDIR_SIZE	(1UL << PGDIR_SHIFT)
47 #define PGDIR_MASK	(~(PGDIR_SIZE-1))
48 
49 /*
50  * entries per page directory level: the m68k is configured as three-level,
51  * so we do have PMD level physically.
52  */
53 #ifdef CONFIG_SUN3
54 #define PTRS_PER_PTE   16
55 #define PTRS_PER_PMD   1
56 #define PTRS_PER_PGD   2048
57 #else
58 #define PTRS_PER_PTE	1024
59 #define PTRS_PER_PMD	8
60 #define PTRS_PER_PGD	128
61 #endif
62 #define USER_PTRS_PER_PGD	(TASK_SIZE/PGDIR_SIZE)
63 #define FIRST_USER_ADDRESS	0
64 
65 /* Virtual address region for use by kernel_map() */
66 #ifdef CONFIG_SUN3
67 #define KMAP_START     0x0DC00000
68 #define KMAP_END       0x0E000000
69 #else
70 #define	KMAP_START	0xd0000000
71 #define	KMAP_END	0xf0000000
72 #endif
73 
74 #ifndef CONFIG_SUN3
75 /* Just any arbitrary offset to the start of the vmalloc VM area: the
76  * current 8MB value just means that there will be a 8MB "hole" after the
77  * physical memory until the kernel virtual memory starts.  That means that
78  * any out-of-bounds memory accesses will hopefully be caught.
79  * The vmalloc() routines leaves a hole of 4kB between each vmalloced
80  * area for the same reason. ;)
81  */
82 #define VMALLOC_OFFSET	(8*1024*1024)
83 #define VMALLOC_START (((unsigned long) high_memory + VMALLOC_OFFSET) & ~(VMALLOC_OFFSET-1))
84 #define VMALLOC_END KMAP_START
85 #else
86 extern unsigned long vmalloc_end;
87 #define VMALLOC_START 0x0f800000
88 #define VMALLOC_END vmalloc_end
89 #endif /* CONFIG_SUN3 */
90 
91 /* zero page used for uninitialized stuff */
92 extern void *empty_zero_page;
93 
94 /*
95  * ZERO_PAGE is a global shared page that is always zero: used
96  * for zero-mapped memory areas etc..
97  */
98 #define ZERO_PAGE(vaddr)	(virt_to_page(empty_zero_page))
99 
100 /* number of bits that fit into a memory pointer */
101 #define BITS_PER_PTR			(8*sizeof(unsigned long))
102 
103 /* to align the pointer to a pointer address */
104 #define PTR_MASK			(~(sizeof(void*)-1))
105 
106 /* sizeof(void*)==1<<SIZEOF_PTR_LOG2 */
107 /* 64-bit machines, beware!  SRB. */
108 #define SIZEOF_PTR_LOG2			       2
109 
110 extern void kernel_set_cachemode(void *addr, unsigned long size, int cmode);
111 
112 /*
113  * The m68k doesn't have any external MMU info: the kernel page
114  * tables contain all the necessary information.  The Sun3 does, but
115  * they are updated on demand.
116  */
117 static inline void update_mmu_cache(struct vm_area_struct *vma,
118 				    unsigned long address, pte_t pte)
119 {
120 }
121 
122 #endif /* !__ASSEMBLY__ */
123 
124 #define kern_addr_valid(addr)	(1)
125 
126 #define io_remap_pfn_range(vma, vaddr, pfn, size, prot)		\
127 		remap_pfn_range(vma, vaddr, pfn, size, prot)
128 
129 /* MMU-specific headers */
130 
131 #ifdef CONFIG_SUN3
132 #include <asm/sun3_pgtable.h>
133 #else
134 #include <asm/motorola_pgtable.h>
135 #endif
136 
137 #ifndef __ASSEMBLY__
138 #include <asm-generic/pgtable.h>
139 
140 /*
141  * Macro to mark a page protection value as "uncacheable".
142  */
143 #ifdef SUN3_PAGE_NOCACHE
144 # define __SUN3_PAGE_NOCACHE	SUN3_PAGE_NOCACHE
145 #else
146 # define __SUN3_PAGE_NOCACHE	0
147 #endif
148 #define pgprot_noncached(prot)							\
149 	(MMU_IS_SUN3								\
150 	 ? (__pgprot(pgprot_val(prot) | __SUN3_PAGE_NOCACHE))			\
151 	 : ((MMU_IS_851 || MMU_IS_030)						\
152 	    ? (__pgprot(pgprot_val(prot) | _PAGE_NOCACHE030))			\
153 	    : (MMU_IS_040 || MMU_IS_060)					\
154 	    ? (__pgprot((pgprot_val(prot) & _CACHEMASK040) | _PAGE_NOCACHE_S))	\
155 	    : (prot)))
156 
157 #endif /* !__ASSEMBLY__ */
158 
159 /*
160  * No page table caches to initialise
161  */
162 #define pgtable_cache_init()	do { } while (0)
163 
164 #define check_pgt_cache()	do { } while (0)
165 
166 #endif /* _M68K_PGTABLE_H */
167