1/*
  2 * Copyright 2010 Tilera Corporation. All Rights Reserved.
  3 *
  4 *   This program is free software; you can redistribute it and/or
  5 *   modify it under the terms of the GNU General Public License
  6 *   as published by the Free Software Foundation, version 2.
  7 *
  8 *   This program is distributed in the hope that it will be useful, but
  9 *   WITHOUT ANY WARRANTY; without even the implied warranty of
 10 *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 11 *   NON INFRINGEMENT.  See the GNU General Public License for
 12 *   more details.
 13 */
 14
 15#ifndef _ASM_TILE_PAGE_H
 16#define _ASM_TILE_PAGE_H
 17
 18#include <linux/const.h>
 19#include <hv/hypervisor.h>
 20#include <arch/chip.h>
 21
 22/* PAGE_SHIFT and HPAGE_SHIFT determine the page sizes. */
 23#define PAGE_SHIFT	HV_LOG2_PAGE_SIZE_SMALL
 24#define HPAGE_SHIFT	HV_LOG2_PAGE_SIZE_LARGE
 25
 26#define PAGE_SIZE	(_AC(1, UL) << PAGE_SHIFT)
 27#define HPAGE_SIZE	(_AC(1, UL) << HPAGE_SHIFT)
 28
 29#define PAGE_MASK	(~(PAGE_SIZE - 1))
 30#define HPAGE_MASK	(~(HPAGE_SIZE - 1))
 31
 32/*
 33 * If the Kconfig doesn't specify, set a maximum zone order that
 34 * is enough so that we can create huge pages from small pages given
 35 * the respective sizes of the two page types.  See <linux/mmzone.h>.
 36 */
 37#ifndef CONFIG_FORCE_MAX_ZONEORDER
 38#define CONFIG_FORCE_MAX_ZONEORDER (HPAGE_SHIFT - PAGE_SHIFT + 1)
 39#endif
 40
 41#ifndef __ASSEMBLY__
 42
 43#include <linux/types.h>
 44#include <linux/string.h>
 45
 46struct page;
 47
 48static inline void clear_page(void *page)
 49{
 50	memset(page, 0, PAGE_SIZE);
 51}
 52
 53static inline void copy_page(void *to, void *from)
 54{
 55	memcpy(to, from, PAGE_SIZE);
 56}
 57
 58static inline void clear_user_page(void *page, unsigned long vaddr,
 59				struct page *pg)
 60{
 61	clear_page(page);
 62}
 63
 64static inline void copy_user_page(void *to, void *from, unsigned long vaddr,
 65				struct page *topage)
 66{
 67	copy_page(to, from);
 68}
 69
 70/*
 71 * Hypervisor page tables are made of the same basic structure.
 72 */
 73
 74typedef HV_PTE pte_t;
 75typedef HV_PTE pgd_t;
 76typedef HV_PTE pgprot_t;
 77
 78/*
 79 * User L2 page tables are managed as one L2 page table per page,
 80 * because we use the page allocator for them.  This keeps the allocation
 81 * simple and makes it potentially useful to implement HIGHPTE at some point.
 82 * However, it's also inefficient, since L2 page tables are much smaller
 83 * than pages (currently 2KB vs 64KB).  So we should revisit this.
 84 */
 85typedef struct page *pgtable_t;
 86
 87/* Must be a macro since it is used to create constants. */
 88#define __pgprot(val) hv_pte(val)
 89
 90/* Rarely-used initializers, typically with a "zero" value. */
 91#define __pte(x) hv_pte(x)
 92#define __pgd(x) hv_pte(x)
 93
 94static inline u64 pgprot_val(pgprot_t pgprot)
 95{
 96	return hv_pte_val(pgprot);
 97}
 98
 99static inline u64 pte_val(pte_t pte)
100{
101	return hv_pte_val(pte);
102}
103
104static inline u64 pgd_val(pgd_t pgd)
105{
106	return hv_pte_val(pgd);
107}
108
109#ifdef __tilegx__
110
111typedef HV_PTE pmd_t;
112
113#define __pmd(x) hv_pte(x)
114
115static inline u64 pmd_val(pmd_t pmd)
116{
117	return hv_pte_val(pmd);
118}
119
120#endif
121
122static inline __attribute_const__ int get_order(unsigned long size)
123{
124	return BITS_PER_LONG - __builtin_clzl((size - 1) >> PAGE_SHIFT);
125}
126
127#endif /* !__ASSEMBLY__ */
128
129#define HUGETLB_PAGE_ORDER	(HPAGE_SHIFT - PAGE_SHIFT)
130
131#define HUGE_MAX_HSTATE		2
132
133#ifdef CONFIG_HUGETLB_PAGE
134#define HAVE_ARCH_HUGETLB_UNMAPPED_AREA
135#endif
136
137/* Each memory controller has PAs distinct in their high bits. */
138#define NR_PA_HIGHBIT_SHIFT (CHIP_PA_WIDTH() - CHIP_LOG_NUM_MSHIMS())
139#define NR_PA_HIGHBIT_VALUES (1 << CHIP_LOG_NUM_MSHIMS())
140#define __pa_to_highbits(pa) ((phys_addr_t)(pa) >> NR_PA_HIGHBIT_SHIFT)
141#define __pfn_to_highbits(pfn) ((pfn) >> (NR_PA_HIGHBIT_SHIFT - PAGE_SHIFT))
142
143#ifdef __tilegx__
144
145/*
146 * We reserve the lower half of memory for user-space programs, and the
147 * upper half for system code.  We re-map all of physical memory in the
148 * upper half, which takes a quarter of our VA space.  Then we have
149 * the vmalloc regions.  The supervisor code lives at 0xfffffff700000000,
150 * with the hypervisor above that.
151 *
152 * Loadable kernel modules are placed immediately after the static
153 * supervisor code, with each being allocated a 256MB region of
154 * address space, so we don't have to worry about the range of "jal"
155 * and other branch instructions.
156 *
157 * For now we keep life simple and just allocate one pmd (4GB) for vmalloc.
158 * Similarly, for now we don't play any struct page mapping games.
159 */
160
161#if CHIP_PA_WIDTH() + 2 > CHIP_VA_WIDTH()
162# error Too much PA to map with the VA available!
163#endif
164#define HALF_VA_SPACE           (_AC(1, UL) << (CHIP_VA_WIDTH() - 1))
165
166#define MEM_LOW_END		(HALF_VA_SPACE - 1)         /* low half */
167#define MEM_HIGH_START		(-HALF_VA_SPACE)            /* high half */
168#define PAGE_OFFSET		MEM_HIGH_START
169#define _VMALLOC_START		_AC(0xfffffff500000000, UL) /* 4 GB */
170#define HUGE_VMAP_BASE		_AC(0xfffffff600000000, UL) /* 4 GB */
171#define MEM_SV_START		_AC(0xfffffff700000000, UL) /* 256 MB */
172#define MEM_SV_INTRPT		MEM_SV_START
173#define MEM_MODULE_START	_AC(0xfffffff710000000, UL) /* 256 MB */
174#define MEM_MODULE_END		(MEM_MODULE_START + (256*1024*1024))
175#define MEM_HV_START		_AC(0xfffffff800000000, UL) /* 32 GB */
176
177/* Highest DTLB address we will use */
178#define KERNEL_HIGH_VADDR	MEM_SV_START
179
180/* Since we don't currently provide any fixmaps, we use an impossible VA. */
181#define FIXADDR_TOP             MEM_HV_START
182
183#else /* !__tilegx__ */
184
185/*
186 * A PAGE_OFFSET of 0xC0000000 means that the kernel has
187 * a virtual address space of one gigabyte, which limits the
188 * amount of physical memory you can use to about 768MB.
189 * If you want more physical memory than this then see the CONFIG_HIGHMEM
190 * option in the kernel configuration.
191 *
192 * The top 16MB chunk in the table below is unavailable to Linux.  Since
193 * the kernel interrupt vectors must live at ether 0xfe000000 or 0xfd000000
194 * (depending on whether the kernel is at PL2 or Pl1), we map all of the
195 * bottom of RAM at this address with a huge page table entry to minimize
196 * its ITLB footprint (as well as at PAGE_OFFSET).  The last architected
197 * requirement is that user interrupt vectors live at 0xfc000000, so we
198 * make that range of memory available to user processes.  The remaining
199 * regions are sized as shown; the first four addresses use the PL 1
200 * values, and after that, we show "typical" values, since the actual
201 * addresses depend on kernel #defines.
202 *
203 * MEM_HV_INTRPT                   0xfe000000
204 * MEM_SV_INTRPT (kernel code)     0xfd000000
205 * MEM_USER_INTRPT (user vector)   0xfc000000
206 * FIX_KMAP_xxx                    0xf8000000 (via NR_CPUS * KM_TYPE_NR)
207 * PKMAP_BASE                      0xf7000000 (via LAST_PKMAP)
208 * HUGE_VMAP                       0xf3000000 (via CONFIG_NR_HUGE_VMAPS)
209 * VMALLOC_START                   0xf0000000 (via __VMALLOC_RESERVE)
210 * mapped LOWMEM                   0xc0000000
211 */
212
213#define MEM_USER_INTRPT		_AC(0xfc000000, UL)
214#if CONFIG_KERNEL_PL == 1
215#define MEM_SV_INTRPT		_AC(0xfd000000, UL)
216#define MEM_HV_INTRPT		_AC(0xfe000000, UL)
217#else
218#define MEM_GUEST_INTRPT	_AC(0xfd000000, UL)
219#define MEM_SV_INTRPT		_AC(0xfe000000, UL)
220#define MEM_HV_INTRPT		_AC(0xff000000, UL)
221#endif
222
223#define INTRPT_SIZE		0x4000
224
225/* Tolerate page size larger than the architecture interrupt region size. */
226#if PAGE_SIZE > INTRPT_SIZE
227#undef INTRPT_SIZE
228#define INTRPT_SIZE PAGE_SIZE
229#endif
230
231#define KERNEL_HIGH_VADDR	MEM_USER_INTRPT
232#define FIXADDR_TOP		(KERNEL_HIGH_VADDR - PAGE_SIZE)
233
234#define PAGE_OFFSET		_AC(CONFIG_PAGE_OFFSET, UL)
235
236/* On 32-bit architectures we mix kernel modules in with other vmaps. */
237#define MEM_MODULE_START	VMALLOC_START
238#define MEM_MODULE_END		VMALLOC_END
239
240#endif /* __tilegx__ */
241
242#ifndef __ASSEMBLY__
243
244#ifdef CONFIG_HIGHMEM
245
246/* Map kernel virtual addresses to page frames, in HPAGE_SIZE chunks. */
247extern unsigned long pbase_map[];
248extern void *vbase_map[];
249
250static inline unsigned long kaddr_to_pfn(const volatile void *_kaddr)
251{
252	unsigned long kaddr = (unsigned long)_kaddr;
253	return pbase_map[kaddr >> HPAGE_SHIFT] +
254		((kaddr & (HPAGE_SIZE - 1)) >> PAGE_SHIFT);
255}
256
257static inline void *pfn_to_kaddr(unsigned long pfn)
258{
259	return vbase_map[__pfn_to_highbits(pfn)] + (pfn << PAGE_SHIFT);
260}
261
262static inline phys_addr_t virt_to_phys(const volatile void *kaddr)
263{
264	unsigned long pfn = kaddr_to_pfn(kaddr);
265	return ((phys_addr_t)pfn << PAGE_SHIFT) +
266		((unsigned long)kaddr & (PAGE_SIZE-1));
267}
268
269static inline void *phys_to_virt(phys_addr_t paddr)
270{
271	return pfn_to_kaddr(paddr >> PAGE_SHIFT) + (paddr & (PAGE_SIZE-1));
272}
273
274/* With HIGHMEM, we pack PAGE_OFFSET through high_memory with all valid VAs. */
275static inline int virt_addr_valid(const volatile void *kaddr)
276{
277	extern void *high_memory;  /* copied from <linux/mm.h> */
278	return ((unsigned long)kaddr >= PAGE_OFFSET && kaddr < high_memory);
279}
280
281#else /* !CONFIG_HIGHMEM */
282
283static inline unsigned long kaddr_to_pfn(const volatile void *kaddr)
284{
285	return ((unsigned long)kaddr - PAGE_OFFSET) >> PAGE_SHIFT;
286}
287
288static inline void *pfn_to_kaddr(unsigned long pfn)
289{
290	return (void *)((pfn << PAGE_SHIFT) + PAGE_OFFSET);
291}
292
293static inline phys_addr_t virt_to_phys(const volatile void *kaddr)
294{
295	return (phys_addr_t)((unsigned long)kaddr - PAGE_OFFSET);
296}
297
298static inline void *phys_to_virt(phys_addr_t paddr)
299{
300	return (void *)((unsigned long)paddr + PAGE_OFFSET);
301}
302
303/* Check that the given address is within some mapped range of PAs. */
304#define virt_addr_valid(kaddr) pfn_valid(kaddr_to_pfn(kaddr))
305
306#endif /* !CONFIG_HIGHMEM */
307
308/* All callers are not consistent in how they call these functions. */
309#define __pa(kaddr) virt_to_phys((void *)(unsigned long)(kaddr))
310#define __va(paddr) phys_to_virt((phys_addr_t)(paddr))
311
312extern int devmem_is_allowed(unsigned long pagenr);
313
314#ifdef CONFIG_FLATMEM
315static inline int pfn_valid(unsigned long pfn)
316{
317	return pfn < max_mapnr;
318}
319#endif
320
321/* Provide as macros since these require some other headers included. */
322#define page_to_pa(page) ((phys_addr_t)(page_to_pfn(page)) << PAGE_SHIFT)
323#define virt_to_page(kaddr) pfn_to_page(kaddr_to_pfn((void *)(kaddr)))
324#define page_to_virt(page) pfn_to_kaddr(page_to_pfn(page))
325
326struct mm_struct;
327extern pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr);
328
329#endif /* !__ASSEMBLY__ */
330
331#define VM_DATA_DEFAULT_FLAGS \
332	(VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
333
334#include <asm-generic/memory_model.h>
335
336#endif /* _ASM_TILE_PAGE_H */