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#if defined(CONFIG_PAGE_SIZE_16KB)
 24#define PAGE_SHIFT	14
 25#define CTX_PAGE_FLAG	HV_CTX_PG_SM_16K
 26#elif defined(CONFIG_PAGE_SIZE_64KB)
 27#define PAGE_SHIFT	16
 28#define CTX_PAGE_FLAG	HV_CTX_PG_SM_64K
 29#else
 30#define PAGE_SHIFT	HV_LOG2_DEFAULT_PAGE_SIZE_SMALL
 31#define CTX_PAGE_FLAG	0
 32#endif
 33#define HPAGE_SHIFT	HV_LOG2_DEFAULT_PAGE_SIZE_LARGE
 34
 35#define PAGE_SIZE	(_AC(1, UL) << PAGE_SHIFT)
 36#define HPAGE_SIZE	(_AC(1, UL) << HPAGE_SHIFT)
 37
 38#define PAGE_MASK	(~(PAGE_SIZE - 1))
 39#define HPAGE_MASK	(~(HPAGE_SIZE - 1))
 40
 41/*
 42 * We do define AT_SYSINFO_EHDR to support vDSO,
 43 * but don't use the gate mechanism.
 44 */
 45#define __HAVE_ARCH_GATE_AREA		1
 46
 47/*
 48 * If the Kconfig doesn't specify, set a maximum zone order that
 49 * is enough so that we can create huge pages from small pages given
 50 * the respective sizes of the two page types.  See <linux/mmzone.h>.
 51 */
 52#ifndef CONFIG_FORCE_MAX_ZONEORDER
 53#define CONFIG_FORCE_MAX_ZONEORDER (HPAGE_SHIFT - PAGE_SHIFT + 1)
 54#endif
 55
 56#ifndef __ASSEMBLY__
 57
 58#include <linux/types.h>
 59#include <linux/string.h>
 60
 61struct page;
 62
 63static inline void clear_page(void *page)
 64{
 65	memset(page, 0, PAGE_SIZE);
 66}
 67
 68static inline void copy_page(void *to, void *from)
 69{
 70	memcpy(to, from, PAGE_SIZE);
 71}
 72
 73static inline void clear_user_page(void *page, unsigned long vaddr,
 74				struct page *pg)
 75{
 76	clear_page(page);
 77}
 78
 79static inline void copy_user_page(void *to, void *from, unsigned long vaddr,
 80				struct page *topage)
 81{
 82	copy_page(to, from);
 83}
 84
 85/*
 86 * Hypervisor page tables are made of the same basic structure.
 87 */
 88
 89typedef HV_PTE pte_t;
 90typedef HV_PTE pgd_t;
 91typedef HV_PTE pgprot_t;
 92
 93/*
 94 * User L2 page tables are managed as one L2 page table per page,
 95 * because we use the page allocator for them.  This keeps the allocation
 96 * simple, but it's also inefficient, since L2 page tables are much smaller
 97 * than pages (currently 2KB vs 64KB).  So we should revisit this.
 98 */
 99typedef struct page *pgtable_t;
100
101/* Must be a macro since it is used to create constants. */
102#define __pgprot(val) hv_pte(val)
103
104/* Rarely-used initializers, typically with a "zero" value. */
105#define __pte(x) hv_pte(x)
106#define __pgd(x) hv_pte(x)
107
108static inline u64 pgprot_val(pgprot_t pgprot)
109{
110	return hv_pte_val(pgprot);
111}
112
113static inline u64 pte_val(pte_t pte)
114{
115	return hv_pte_val(pte);
116}
117
118static inline u64 pgd_val(pgd_t pgd)
119{
120	return hv_pte_val(pgd);
121}
122
123#ifdef __tilegx__
124
125typedef HV_PTE pmd_t;
126
127#define __pmd(x) hv_pte(x)
128
129static inline u64 pmd_val(pmd_t pmd)
130{
131	return hv_pte_val(pmd);
132}
133
134#endif
135
136static inline __attribute_const__ int get_order(unsigned long size)
137{
138	return BITS_PER_LONG - __builtin_clzl((size - 1) >> PAGE_SHIFT);
139}
140
141#endif /* !__ASSEMBLY__ */
142
143#define HUGETLB_PAGE_ORDER	(HPAGE_SHIFT - PAGE_SHIFT)
144
145#define HUGE_MAX_HSTATE		6
146
147#ifdef CONFIG_HUGETLB_PAGE
148#define HAVE_ARCH_HUGETLB_UNMAPPED_AREA
149#endif
150
151/* Allow overriding how much VA or PA the kernel will use. */
152#define MAX_PA_WIDTH CHIP_PA_WIDTH()
153#define MAX_VA_WIDTH CHIP_VA_WIDTH()
154
155/* Each memory controller has PAs distinct in their high bits. */
156#define NR_PA_HIGHBIT_SHIFT (MAX_PA_WIDTH - CHIP_LOG_NUM_MSHIMS())
157#define NR_PA_HIGHBIT_VALUES (1 << CHIP_LOG_NUM_MSHIMS())
158#define __pa_to_highbits(pa) ((phys_addr_t)(pa) >> NR_PA_HIGHBIT_SHIFT)
159#define __pfn_to_highbits(pfn) ((pfn) >> (NR_PA_HIGHBIT_SHIFT - PAGE_SHIFT))
160
161#ifdef __tilegx__
162
163/*
164 * We reserve the lower half of memory for user-space programs, and the
165 * upper half for system code.  We re-map all of physical memory in the
166 * upper half, which takes a quarter of our VA space.  Then we have
167 * the vmalloc regions.  The supervisor code lives at the highest address,
168 * with the hypervisor above that.
169 *
170 * Loadable kernel modules are placed immediately after the static
171 * supervisor code, with each being allocated a 256MB region of
172 * address space, so we don't have to worry about the range of "jal"
173 * and other branch instructions.
174 *
175 * For now we keep life simple and just allocate one pmd (4GB) for vmalloc.
176 * Similarly, for now we don't play any struct page mapping games.
177 */
178
179#if MAX_PA_WIDTH + 2 > MAX_VA_WIDTH
180# error Too much PA to map with the VA available!
181#endif
182
183#define PAGE_OFFSET		(-(_AC(1, UL) << (MAX_VA_WIDTH - 1)))
184#define KERNEL_HIGH_VADDR	_AC(0xfffffff800000000, UL)  /* high 32GB */
185#define FIXADDR_BASE		(KERNEL_HIGH_VADDR - 0x300000000) /* 4 GB */
186#define FIXADDR_TOP		(KERNEL_HIGH_VADDR - 0x200000000) /* 4 GB */
187#define _VMALLOC_START		FIXADDR_TOP
188#define MEM_SV_START		(KERNEL_HIGH_VADDR - 0x100000000) /* 256 MB */
189#define MEM_MODULE_START	(MEM_SV_START + (256*1024*1024)) /* 256 MB */
190#define MEM_MODULE_END		(MEM_MODULE_START + (256*1024*1024))
191
192#else /* !__tilegx__ */
193
194/*
195 * A PAGE_OFFSET of 0xC0000000 means that the kernel has
196 * a virtual address space of one gigabyte, which limits the
197 * amount of physical memory you can use to about 768MB.
198 * If you want more physical memory than this then see the CONFIG_HIGHMEM
199 * option in the kernel configuration.
200 *
201 * The top 16MB chunk in the table below is unavailable to Linux.  Since
202 * the kernel interrupt vectors must live at ether 0xfe000000 or 0xfd000000
203 * (depending on whether the kernel is at PL2 or Pl1), we map all of the
204 * bottom of RAM at this address with a huge page table entry to minimize
205 * its ITLB footprint (as well as at PAGE_OFFSET).  The last architected
206 * requirement is that user interrupt vectors live at 0xfc000000, so we
207 * make that range of memory available to user processes.  The remaining
208 * regions are sized as shown; the first four addresses use the PL 1
209 * values, and after that, we show "typical" values, since the actual
210 * addresses depend on kernel #defines.
211 *
212 * MEM_HV_START                    0xfe000000
213 * MEM_SV_START  (kernel code)     0xfd000000
214 * MEM_USER_INTRPT (user vector)   0xfc000000
215 * FIX_KMAP_xxx                    0xfa000000 (via NR_CPUS * KM_TYPE_NR)
216 * PKMAP_BASE                      0xf9000000 (via LAST_PKMAP)
217 * VMALLOC_START                   0xf7000000 (via VMALLOC_RESERVE)
218 * mapped LOWMEM                   0xc0000000
219 */
220
221#define MEM_USER_INTRPT		_AC(0xfc000000, UL)
222#define MEM_SV_START		_AC(0xfd000000, UL)
223#define MEM_HV_START		_AC(0xfe000000, UL)
224
225#define INTRPT_SIZE		0x4000
226
227/* Tolerate page size larger than the architecture interrupt region size. */
228#if PAGE_SIZE > INTRPT_SIZE
229#undef INTRPT_SIZE
230#define INTRPT_SIZE PAGE_SIZE
231#endif
232
233#define KERNEL_HIGH_VADDR	MEM_USER_INTRPT
234#define FIXADDR_TOP		(KERNEL_HIGH_VADDR - PAGE_SIZE)
235
236#define PAGE_OFFSET		_AC(CONFIG_PAGE_OFFSET, UL)
237
238/* On 32-bit architectures we mix kernel modules in with other vmaps. */
239#define MEM_MODULE_START	VMALLOC_START
240#define MEM_MODULE_END		VMALLOC_END
241
242#endif /* __tilegx__ */
243
244#if !defined(__ASSEMBLY__) && !defined(VDSO_BUILD)
245
246#ifdef CONFIG_HIGHMEM
247
248/* Map kernel virtual addresses to page frames, in HPAGE_SIZE chunks. */
249extern unsigned long pbase_map[];
250extern void *vbase_map[];
251
252static inline unsigned long kaddr_to_pfn(const volatile void *_kaddr)
253{
254	unsigned long kaddr = (unsigned long)_kaddr;
255	return pbase_map[kaddr >> HPAGE_SHIFT] +
256		((kaddr & (HPAGE_SIZE - 1)) >> PAGE_SHIFT);
257}
258
259static inline void *pfn_to_kaddr(unsigned long pfn)
260{
261	return vbase_map[__pfn_to_highbits(pfn)] + (pfn << PAGE_SHIFT);
262}
263
264static inline phys_addr_t virt_to_phys(const volatile void *kaddr)
265{
266	unsigned long pfn = kaddr_to_pfn(kaddr);
267	return ((phys_addr_t)pfn << PAGE_SHIFT) +
268		((unsigned long)kaddr & (PAGE_SIZE-1));
269}
270
271static inline void *phys_to_virt(phys_addr_t paddr)
272{
273	return pfn_to_kaddr(paddr >> PAGE_SHIFT) + (paddr & (PAGE_SIZE-1));
274}
275
276/* With HIGHMEM, we pack PAGE_OFFSET through high_memory with all valid VAs. */
277static inline int virt_addr_valid(const volatile void *kaddr)
278{
279	extern void *high_memory;  /* copied from <linux/mm.h> */
280	return ((unsigned long)kaddr >= PAGE_OFFSET && kaddr < high_memory);
281}
282
283#else /* !CONFIG_HIGHMEM */
284
285static inline unsigned long kaddr_to_pfn(const volatile void *kaddr)
286{
287	return ((unsigned long)kaddr - PAGE_OFFSET) >> PAGE_SHIFT;
288}
289
290static inline void *pfn_to_kaddr(unsigned long pfn)
291{
292	return (void *)((pfn << PAGE_SHIFT) + PAGE_OFFSET);
293}
294
295static inline phys_addr_t virt_to_phys(const volatile void *kaddr)
296{
297	return (phys_addr_t)((unsigned long)kaddr - PAGE_OFFSET);
298}
299
300static inline void *phys_to_virt(phys_addr_t paddr)
301{
302	return (void *)((unsigned long)paddr + PAGE_OFFSET);
303}
304
305/* Check that the given address is within some mapped range of PAs. */
306#define virt_addr_valid(kaddr) pfn_valid(kaddr_to_pfn(kaddr))
307
308#endif /* !CONFIG_HIGHMEM */
309
310/* All callers are not consistent in how they call these functions. */
311#define __pa(kaddr) virt_to_phys((void *)(unsigned long)(kaddr))
312#define __va(paddr) phys_to_virt((phys_addr_t)(paddr))
313
314extern int devmem_is_allowed(unsigned long pagenr);
315
316#ifdef CONFIG_FLATMEM
317static inline int pfn_valid(unsigned long pfn)
318{
319	return pfn < max_mapnr;
320}
321#endif
322
323/* Provide as macros since these require some other headers included. */
324#define page_to_pa(page) ((phys_addr_t)(page_to_pfn(page)) << PAGE_SHIFT)
325#define virt_to_page(kaddr) pfn_to_page(kaddr_to_pfn((void *)(kaddr)))
326#define page_to_virt(page) pfn_to_kaddr(page_to_pfn(page))
327
328struct mm_struct;
329extern pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr);
330extern pte_t *virt_to_kpte(unsigned long kaddr);
331
332#endif /* !__ASSEMBLY__ */
333
334#define VM_DATA_DEFAULT_FLAGS \
335	(VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
336
337#include <asm-generic/memory_model.h>
338
339#endif /* _ASM_TILE_PAGE_H */