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_4KB)  /* tilepro only */
 24#define PAGE_SHIFT	12
 25#define CTX_PAGE_FLAG	HV_CTX_PG_SM_4K
 26#elif defined(CONFIG_PAGE_SIZE_16KB)
 27#define PAGE_SHIFT	14
 28#define CTX_PAGE_FLAG	HV_CTX_PG_SM_16K
 29#elif defined(CONFIG_PAGE_SIZE_64KB)
 30#define PAGE_SHIFT	16
 31#define CTX_PAGE_FLAG	HV_CTX_PG_SM_64K
 32#else
 33#error Page size not specified in Kconfig
 34#endif
 35#define HPAGE_SHIFT	HV_LOG2_DEFAULT_PAGE_SIZE_LARGE
 36
 37#define PAGE_SIZE	(_AC(1, UL) << PAGE_SHIFT)
 38#define HPAGE_SIZE	(_AC(1, UL) << HPAGE_SHIFT)
 39
 40#define PAGE_MASK	(~(PAGE_SIZE - 1))
 41#define HPAGE_MASK	(~(HPAGE_SIZE - 1))
 42
 43/*
 44 * If the Kconfig doesn't specify, set a maximum zone order that
 45 * is enough so that we can create huge pages from small pages given
 46 * the respective sizes of the two page types.  See <linux/mmzone.h>.
 47 */
 48#ifndef CONFIG_FORCE_MAX_ZONEORDER
 49#define CONFIG_FORCE_MAX_ZONEORDER (HPAGE_SHIFT - PAGE_SHIFT + 1)
 50#endif
 51
 52#ifndef __ASSEMBLY__
 53
 54#include <linux/types.h>
 55#include <linux/string.h>
 56
 57struct page;
 58
 59static inline void clear_page(void *page)
 60{
 61	memset(page, 0, PAGE_SIZE);
 62}
 63
 64static inline void copy_page(void *to, void *from)
 65{
 66	memcpy(to, from, PAGE_SIZE);
 67}
 68
 69static inline void clear_user_page(void *page, unsigned long vaddr,
 70				struct page *pg)
 71{
 72	clear_page(page);
 73}
 74
 75static inline void copy_user_page(void *to, void *from, unsigned long vaddr,
 76				struct page *topage)
 77{
 78	copy_page(to, from);
 79}
 80
 81/*
 82 * Hypervisor page tables are made of the same basic structure.
 83 */
 84
 85typedef HV_PTE pte_t;
 86typedef HV_PTE pgd_t;
 87typedef HV_PTE pgprot_t;
 88
 89/*
 90 * User L2 page tables are managed as one L2 page table per page,
 91 * because we use the page allocator for them.  This keeps the allocation
 92 * simple, but it's also inefficient, since L2 page tables are much smaller
 93 * than pages (currently 2KB vs 64KB).  So we should revisit this.
 94 */
 95typedef struct page *pgtable_t;
 96
 97/* Must be a macro since it is used to create constants. */
 98#define __pgprot(val) hv_pte(val)
 99
100/* Rarely-used initializers, typically with a "zero" value. */
101#define __pte(x) hv_pte(x)
102#define __pgd(x) hv_pte(x)
103
104static inline u64 pgprot_val(pgprot_t pgprot)
105{
106	return hv_pte_val(pgprot);
107}
108
109static inline u64 pte_val(pte_t pte)
110{
111	return hv_pte_val(pte);
112}
113
114static inline u64 pgd_val(pgd_t pgd)
115{
116	return hv_pte_val(pgd);
117}
118
119#ifdef __tilegx__
120
121typedef HV_PTE pmd_t;
122
123#define __pmd(x) hv_pte(x)
124
125static inline u64 pmd_val(pmd_t pmd)
126{
127	return hv_pte_val(pmd);
128}
129
130#endif
131
132static inline __attribute_const__ int get_order(unsigned long size)
133{
134	return BITS_PER_LONG - __builtin_clzl((size - 1) >> PAGE_SHIFT);
135}
136
137#endif /* !__ASSEMBLY__ */
138
139#define HUGETLB_PAGE_ORDER	(HPAGE_SHIFT - PAGE_SHIFT)
140
141#define HUGE_MAX_HSTATE		6
142
143#ifdef CONFIG_HUGETLB_PAGE
144#define HAVE_ARCH_HUGETLB_UNMAPPED_AREA
145#endif
146
147/* Allow overriding how much VA or PA the kernel will use. */
148#define MAX_PA_WIDTH CHIP_PA_WIDTH()
149#define MAX_VA_WIDTH CHIP_VA_WIDTH()
150
151/* Each memory controller has PAs distinct in their high bits. */
152#define NR_PA_HIGHBIT_SHIFT (MAX_PA_WIDTH - CHIP_LOG_NUM_MSHIMS())
153#define NR_PA_HIGHBIT_VALUES (1 << CHIP_LOG_NUM_MSHIMS())
154#define __pa_to_highbits(pa) ((phys_addr_t)(pa) >> NR_PA_HIGHBIT_SHIFT)
155#define __pfn_to_highbits(pfn) ((pfn) >> (NR_PA_HIGHBIT_SHIFT - PAGE_SHIFT))
156
157#ifdef __tilegx__
158
159/*
160 * We reserve the lower half of memory for user-space programs, and the
161 * upper half for system code.  We re-map all of physical memory in the
162 * upper half, which takes a quarter of our VA space.  Then we have
163 * the vmalloc regions.  The supervisor code lives at the highest address,
164 * with the hypervisor above that.
165 *
166 * Loadable kernel modules are placed immediately after the static
167 * supervisor code, with each being allocated a 256MB region of
168 * address space, so we don't have to worry about the range of "jal"
169 * and other branch instructions.
170 *
171 * For now we keep life simple and just allocate one pmd (4GB) for vmalloc.
172 * Similarly, for now we don't play any struct page mapping games.
173 */
174
175#if MAX_PA_WIDTH + 2 > MAX_VA_WIDTH
176# error Too much PA to map with the VA available!
177#endif
178
179#define PAGE_OFFSET		(-(_AC(1, UL) << (MAX_VA_WIDTH - 1)))
180#define KERNEL_HIGH_VADDR	_AC(0xfffffff800000000, UL)  /* high 32GB */
181#define FIXADDR_BASE		(KERNEL_HIGH_VADDR - 0x300000000) /* 4 GB */
182#define FIXADDR_TOP		(KERNEL_HIGH_VADDR - 0x200000000) /* 4 GB */
183#define _VMALLOC_START		FIXADDR_TOP
184#define MEM_SV_START		(KERNEL_HIGH_VADDR - 0x100000000) /* 256 MB */
185#define MEM_MODULE_START	(MEM_SV_START + (256*1024*1024)) /* 256 MB */
186#define MEM_MODULE_END		(MEM_MODULE_START + (256*1024*1024))
187
188#else /* !__tilegx__ */
189
190/*
191 * A PAGE_OFFSET of 0xC0000000 means that the kernel has
192 * a virtual address space of one gigabyte, which limits the
193 * amount of physical memory you can use to about 768MB.
194 * If you want more physical memory than this then see the CONFIG_HIGHMEM
195 * option in the kernel configuration.
196 *
197 * The top 16MB chunk in the table below is unavailable to Linux.  Since
198 * the kernel interrupt vectors must live at ether 0xfe000000 or 0xfd000000
199 * (depending on whether the kernel is at PL2 or Pl1), we map all of the
200 * bottom of RAM at this address with a huge page table entry to minimize
201 * its ITLB footprint (as well as at PAGE_OFFSET).  The last architected
202 * requirement is that user interrupt vectors live at 0xfc000000, so we
203 * make that range of memory available to user processes.  The remaining
204 * regions are sized as shown; the first four addresses use the PL 1
205 * values, and after that, we show "typical" values, since the actual
206 * addresses depend on kernel #defines.
207 *
208 * MEM_HV_START                    0xfe000000
209 * MEM_SV_START  (kernel code)     0xfd000000
210 * MEM_USER_INTRPT (user vector)   0xfc000000
211 * FIX_KMAP_xxx                    0xfa000000 (via NR_CPUS * KM_TYPE_NR)
212 * PKMAP_BASE                      0xf9000000 (via LAST_PKMAP)
213 * VMALLOC_START                   0xf7000000 (via VMALLOC_RESERVE)
214 * mapped LOWMEM                   0xc0000000
215 */
216
217#define MEM_USER_INTRPT		_AC(0xfc000000, UL)
218#define MEM_SV_START		_AC(0xfd000000, UL)
219#define MEM_HV_START		_AC(0xfe000000, UL)
220
221#define INTRPT_SIZE		0x4000
222
223/* Tolerate page size larger than the architecture interrupt region size. */
224#if PAGE_SIZE > INTRPT_SIZE
225#undef INTRPT_SIZE
226#define INTRPT_SIZE PAGE_SIZE
227#endif
228
229#define KERNEL_HIGH_VADDR	MEM_USER_INTRPT
230#define FIXADDR_TOP		(KERNEL_HIGH_VADDR - PAGE_SIZE)
231
232#define PAGE_OFFSET		_AC(CONFIG_PAGE_OFFSET, UL)
233
234/* On 32-bit architectures we mix kernel modules in with other vmaps. */
235#define MEM_MODULE_START	VMALLOC_START
236#define MEM_MODULE_END		VMALLOC_END
237
238#endif /* __tilegx__ */
239
240#if !defined(__ASSEMBLY__) && !defined(VDSO_BUILD)
241
242#ifdef CONFIG_HIGHMEM
243
244/* Map kernel virtual addresses to page frames, in HPAGE_SIZE chunks. */
245extern unsigned long pbase_map[];
246extern void *vbase_map[];
247
248static inline unsigned long kaddr_to_pfn(const volatile void *_kaddr)
249{
250	unsigned long kaddr = (unsigned long)_kaddr;
251	return pbase_map[kaddr >> HPAGE_SHIFT] +
252		((kaddr & (HPAGE_SIZE - 1)) >> PAGE_SHIFT);
253}
254
255static inline void *pfn_to_kaddr(unsigned long pfn)
256{
257	return vbase_map[__pfn_to_highbits(pfn)] + (pfn << PAGE_SHIFT);
258}
259
260static inline phys_addr_t virt_to_phys(const volatile void *kaddr)
261{
262	unsigned long pfn = kaddr_to_pfn(kaddr);
263	return ((phys_addr_t)pfn << PAGE_SHIFT) +
264		((unsigned long)kaddr & (PAGE_SIZE-1));
265}
266
267static inline void *phys_to_virt(phys_addr_t paddr)
268{
269	return pfn_to_kaddr(paddr >> PAGE_SHIFT) + (paddr & (PAGE_SIZE-1));
270}
271
272/* With HIGHMEM, we pack PAGE_OFFSET through high_memory with all valid VAs. */
273static inline int virt_addr_valid(const volatile void *kaddr)
274{
275	extern void *high_memory;  /* copied from <linux/mm.h> */
276	return ((unsigned long)kaddr >= PAGE_OFFSET && kaddr < high_memory);
277}
278
279#else /* !CONFIG_HIGHMEM */
280
281static inline unsigned long kaddr_to_pfn(const volatile void *kaddr)
282{
283	return ((unsigned long)kaddr - PAGE_OFFSET) >> PAGE_SHIFT;
284}
285
286static inline void *pfn_to_kaddr(unsigned long pfn)
287{
288	return (void *)((pfn << PAGE_SHIFT) + PAGE_OFFSET);
289}
290
291static inline phys_addr_t virt_to_phys(const volatile void *kaddr)
292{
293	return (phys_addr_t)((unsigned long)kaddr - PAGE_OFFSET);
294}
295
296static inline void *phys_to_virt(phys_addr_t paddr)
297{
298	return (void *)((unsigned long)paddr + PAGE_OFFSET);
299}
300
301/* Check that the given address is within some mapped range of PAs. */
302#define virt_addr_valid(kaddr) pfn_valid(kaddr_to_pfn(kaddr))
303
304#endif /* !CONFIG_HIGHMEM */
305
306/* All callers are not consistent in how they call these functions. */
307#define __pa(kaddr) virt_to_phys((void *)(unsigned long)(kaddr))
308#define __va(paddr) phys_to_virt((phys_addr_t)(paddr))
309
310extern int devmem_is_allowed(unsigned long pagenr);
311
312#ifdef CONFIG_FLATMEM
313static inline int pfn_valid(unsigned long pfn)
314{
315	return pfn < max_mapnr;
316}
317#endif
318
319/* Provide as macros since these require some other headers included. */
320#define page_to_pa(page) ((phys_addr_t)(page_to_pfn(page)) << PAGE_SHIFT)
321#define virt_to_page(kaddr) pfn_to_page(kaddr_to_pfn((void *)(kaddr)))
322#define page_to_virt(page) pfn_to_kaddr(page_to_pfn(page))
323
324/*
325 * The kernel text is mapped at MEM_SV_START as read-only.  To allow
326 * modifying kernel text, it is also mapped at PAGE_OFFSET as read-write.
327 * This macro converts a kernel address to its writable kernel text mapping,
328 * which is used to modify the text code on a running kernel by kgdb,
329 * ftrace, kprobe, jump label, etc.
330 */
331#define ktext_writable_addr(kaddr) \
332	((unsigned long)(kaddr) - MEM_SV_START + PAGE_OFFSET)
333
334struct mm_struct;
335extern pte_t *virt_to_pte(struct mm_struct *mm, unsigned long addr);
336extern pte_t *virt_to_kpte(unsigned long kaddr);
337
338#endif /* !__ASSEMBLY__ */
339
340#define VM_DATA_DEFAULT_FLAGS \
341	(VM_READ | VM_WRITE | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
342
343#include <asm-generic/memory_model.h>
344
345#endif /* _ASM_TILE_PAGE_H */