Merge tag 'backlight-for-linus-4.2' of git://git.kernel.org/pub/scm/linux/kernel...
[linux-2.6-block.git] / arch / arm / mm / nommu.c
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1/*
2 * linux/arch/arm/mm/nommu.c
3 *
4 * ARM uCLinux supporting functions.
5 */
6#include <linux/module.h>
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7#include <linux/mm.h>
8#include <linux/pagemap.h>
fced80c7 9#include <linux/io.h>
2778f620 10#include <linux/memblock.h>
5ad7dcbe 11#include <linux/kernel.h>
5924486d 12
e6b1b38c 13#include <asm/cacheflush.h>
37efe642 14#include <asm/sections.h>
5924486d 15#include <asm/page.h>
b32f3afe 16#include <asm/setup.h>
6b8e5c91 17#include <asm/traps.h>
3ff1559e 18#include <asm/mach/arch.h>
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19#include <asm/cputype.h>
20#include <asm/mpu.h>
83651bb9 21#include <asm/procinfo.h>
5924486d 22
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23#include "mm.h"
24
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25#ifdef CONFIG_ARM_MPU
26struct mpu_rgn_info mpu_rgn_info;
27
28/* Region number */
29static void rgnr_write(u32 v)
30{
31 asm("mcr p15, 0, %0, c6, c2, 0" : : "r" (v));
32}
33
34/* Data-side / unified region attributes */
35
36/* Region access control register */
37static void dracr_write(u32 v)
38{
39 asm("mcr p15, 0, %0, c6, c1, 4" : : "r" (v));
40}
41
42/* Region size register */
43static void drsr_write(u32 v)
44{
45 asm("mcr p15, 0, %0, c6, c1, 2" : : "r" (v));
46}
47
48/* Region base address register */
49static void drbar_write(u32 v)
50{
51 asm("mcr p15, 0, %0, c6, c1, 0" : : "r" (v));
52}
53
54static u32 drbar_read(void)
55{
56 u32 v;
57 asm("mrc p15, 0, %0, c6, c1, 0" : "=r" (v));
58 return v;
59}
60/* Optional instruction-side region attributes */
61
62/* I-side Region access control register */
63static void iracr_write(u32 v)
64{
65 asm("mcr p15, 0, %0, c6, c1, 5" : : "r" (v));
66}
67
68/* I-side Region size register */
69static void irsr_write(u32 v)
70{
71 asm("mcr p15, 0, %0, c6, c1, 3" : : "r" (v));
72}
73
74/* I-side Region base address register */
75static void irbar_write(u32 v)
76{
77 asm("mcr p15, 0, %0, c6, c1, 1" : : "r" (v));
78}
79
80static unsigned long irbar_read(void)
81{
82 unsigned long v;
83 asm("mrc p15, 0, %0, c6, c1, 1" : "=r" (v));
84 return v;
85}
86
87/* MPU initialisation functions */
88void __init sanity_check_meminfo_mpu(void)
89{
90 int i;
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91 phys_addr_t phys_offset = PHYS_OFFSET;
92 phys_addr_t aligned_region_size, specified_mem_size, rounded_mem_size;
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93 struct memblock_region *reg;
94 bool first = true;
95 phys_addr_t mem_start;
96 phys_addr_t mem_end;
97
98 for_each_memblock(memory, reg) {
99 if (first) {
100 /*
101 * Initially only use memory continuous from
102 * PHYS_OFFSET */
103 if (reg->base != phys_offset)
104 panic("First memory bank must be contiguous from PHYS_OFFSET");
105
106 mem_start = reg->base;
107 mem_end = reg->base + reg->size;
108 specified_mem_size = reg->size;
109 first = false;
5ad7dcbe 110 } else {
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111 /*
112 * memblock auto merges contiguous blocks, remove
113 * all blocks afterwards
114 */
115 pr_notice("Ignoring RAM after %pa, memory at %pa ignored\n",
116 &mem_start, &reg->base);
117 memblock_remove(reg->base, reg->size);
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118 }
119 }
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120
121 /*
122 * MPU has curious alignment requirements: Size must be power of 2, and
123 * region start must be aligned to the region size
124 */
125 if (phys_offset != 0)
126 pr_info("PHYS_OFFSET != 0 => MPU Region size constrained by alignment requirements\n");
127
128 /*
129 * Maximum aligned region might overflow phys_addr_t if phys_offset is
130 * 0. Hence we keep everything below 4G until we take the smaller of
131 * the aligned_region_size and rounded_mem_size, one of which is
132 * guaranteed to be smaller than the maximum physical address.
133 */
134 aligned_region_size = (phys_offset - 1) ^ (phys_offset);
135 /* Find the max power-of-two sized region that fits inside our bank */
1c2f87c2 136 rounded_mem_size = (1 << __fls(specified_mem_size)) - 1;
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137
138 /* The actual region size is the smaller of the two */
139 aligned_region_size = aligned_region_size < rounded_mem_size
140 ? aligned_region_size + 1
141 : rounded_mem_size + 1;
142
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143 if (aligned_region_size != specified_mem_size) {
144 pr_warn("Truncating memory from %pa to %pa (MPU region constraints)",
145 &specified_mem_size, &aligned_region_size);
146 memblock_remove(mem_start + aligned_region_size,
147 specified_mem_size - aligned_round_size);
148
149 mem_end = mem_start + aligned_region_size;
150 }
5ad7dcbe 151
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152 pr_debug("MPU Region from %pa size %pa (end %pa))\n",
153 &phys_offset, &aligned_region_size, &mem_end);
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154
155}
156
157static int mpu_present(void)
158{
159 return ((read_cpuid_ext(CPUID_EXT_MMFR0) & MMFR0_PMSA) == MMFR0_PMSAv7);
160}
161
162static int mpu_max_regions(void)
163{
164 /*
165 * We don't support a different number of I/D side regions so if we
166 * have separate instruction and data memory maps then return
167 * whichever side has a smaller number of supported regions.
168 */
169 u32 dregions, iregions, mpuir;
170 mpuir = read_cpuid(CPUID_MPUIR);
171
172 dregions = iregions = (mpuir & MPUIR_DREGION_SZMASK) >> MPUIR_DREGION;
173
174 /* Check for separate d-side and i-side memory maps */
175 if (mpuir & MPUIR_nU)
176 iregions = (mpuir & MPUIR_IREGION_SZMASK) >> MPUIR_IREGION;
177
178 /* Use the smallest of the two maxima */
179 return min(dregions, iregions);
180}
181
182static int mpu_iside_independent(void)
183{
184 /* MPUIR.nU specifies whether there is *not* a unified memory map */
185 return read_cpuid(CPUID_MPUIR) & MPUIR_nU;
186}
187
188static int mpu_min_region_order(void)
189{
190 u32 drbar_result, irbar_result;
191 /* We've kept a region free for this probing */
192 rgnr_write(MPU_PROBE_REGION);
193 isb();
194 /*
195 * As per ARM ARM, write 0xFFFFFFFC to DRBAR to find the minimum
196 * region order
197 */
198 drbar_write(0xFFFFFFFC);
199 drbar_result = irbar_result = drbar_read();
200 drbar_write(0x0);
201 /* If the MPU is non-unified, we use the larger of the two minima*/
202 if (mpu_iside_independent()) {
203 irbar_write(0xFFFFFFFC);
204 irbar_result = irbar_read();
205 irbar_write(0x0);
206 }
207 isb(); /* Ensure that MPU region operations have completed */
208 /* Return whichever result is larger */
209 return __ffs(max(drbar_result, irbar_result));
210}
211
212static int mpu_setup_region(unsigned int number, phys_addr_t start,
213 unsigned int size_order, unsigned int properties)
214{
215 u32 size_data;
216
217 /* We kept a region free for probing resolution of MPU regions*/
218 if (number > mpu_max_regions() || number == MPU_PROBE_REGION)
219 return -ENOENT;
220
221 if (size_order > 32)
222 return -ENOMEM;
223
224 if (size_order < mpu_min_region_order())
225 return -ENOMEM;
226
227 /* Writing N to bits 5:1 (RSR_SZ) specifies region size 2^N+1 */
228 size_data = ((size_order - 1) << MPU_RSR_SZ) | 1 << MPU_RSR_EN;
229
230 dsb(); /* Ensure all previous data accesses occur with old mappings */
231 rgnr_write(number);
232 isb();
233 drbar_write(start);
234 dracr_write(properties);
235 isb(); /* Propagate properties before enabling region */
236 drsr_write(size_data);
237
238 /* Check for independent I-side registers */
239 if (mpu_iside_independent()) {
240 irbar_write(start);
241 iracr_write(properties);
242 isb();
243 irsr_write(size_data);
244 }
245 isb();
246
247 /* Store region info (we treat i/d side the same, so only store d) */
248 mpu_rgn_info.rgns[number].dracr = properties;
249 mpu_rgn_info.rgns[number].drbar = start;
250 mpu_rgn_info.rgns[number].drsr = size_data;
251 return 0;
252}
253
254/*
255* Set up default MPU regions, doing nothing if there is no MPU
256*/
257void __init mpu_setup(void)
258{
259 int region_err;
260 if (!mpu_present())
261 return;
262
263 region_err = mpu_setup_region(MPU_RAM_REGION, PHYS_OFFSET,
264 ilog2(meminfo.bank[0].size),
265 MPU_AP_PL1RW_PL0RW | MPU_RGN_NORMAL);
266 if (region_err) {
267 panic("MPU region initialization failure! %d", region_err);
268 } else {
269 pr_info("Using ARMv7 PMSA Compliant MPU. "
270 "Region independence: %s, Max regions: %d\n",
271 mpu_iside_independent() ? "Yes" : "No",
272 mpu_max_regions());
273 }
274}
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275#else
276static void sanity_check_meminfo_mpu(void) {}
277static void __init mpu_setup(void) {}
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278#endif /* CONFIG_ARM_MPU */
279
2778f620 280void __init arm_mm_memblock_reserve(void)
d111e8f9 281{
55bdd694 282#ifndef CONFIG_CPU_V7M
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283 /*
284 * Register the exception vector page.
285 * some architectures which the DRAM is the exception vector to trap,
286 * alloc_page breaks with error, although it is not NULL, but "0."
287 */
2778f620 288 memblock_reserve(CONFIG_VECTORS_BASE, PAGE_SIZE);
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289#else /* ifndef CONFIG_CPU_V7M */
290 /*
291 * There is no dedicated vector page on V7-M. So nothing needs to be
292 * reserved here.
293 */
294#endif
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295}
296
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297void __init sanity_check_meminfo(void)
298{
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299 phys_addr_t end;
300 sanity_check_meminfo_mpu();
1c2f87c2 301 end = memblock_end_of_DRAM();
55a8173c 302 high_memory = __va(end - 1) + 1;
6980c3e2 303 memblock_set_current_limit(end);
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304}
305
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306/*
307 * early_paging_init() recreates boot time page table setup, allowing machines
308 * to switch over to a high (>4G) address space on LPAE systems
309 */
310void __init early_paging_init(const struct machine_desc *mdesc,
311 struct proc_info_list *procinfo)
312{
313}
314
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315/*
316 * paging_init() sets up the page tables, initialises the zone memory
317 * maps, and sets up the zero page, bad page and bad page tables.
318 */
ff69a4c8 319void __init paging_init(const struct machine_desc *mdesc)
d111e8f9 320{
6b8e5c91 321 early_trap_init((void *)CONFIG_VECTORS_BASE);
9a271567 322 mpu_setup();
8d717a52 323 bootmem_init();
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324}
325
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326/*
327 * We don't need to do anything here for nommu machines.
328 */
5aafec15 329void setup_mm_for_reboot(void)
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330{
331}
332
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333void flush_dcache_page(struct page *page)
334{
2c9b9c84 335 __cpuc_flush_dcache_area(page_address(page), PAGE_SIZE);
e6b1b38c 336}
3e361225 337EXPORT_SYMBOL(flush_dcache_page);
e6b1b38c 338
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339void flush_kernel_dcache_page(struct page *page)
340{
341 __cpuc_flush_dcache_area(page_address(page), PAGE_SIZE);
342}
343EXPORT_SYMBOL(flush_kernel_dcache_page);
344
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345void copy_to_user_page(struct vm_area_struct *vma, struct page *page,
346 unsigned long uaddr, void *dst, const void *src,
347 unsigned long len)
348{
349 memcpy(dst, src, len);
350 if (vma->vm_flags & VM_EXEC)
351 __cpuc_coherent_user_range(uaddr, uaddr + len);
352}
353
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354void __iomem *__arm_ioremap_pfn(unsigned long pfn, unsigned long offset,
355 size_t size, unsigned int mtype)
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356{
357 if (pfn >= (0x100000000ULL >> PAGE_SHIFT))
358 return NULL;
359 return (void __iomem *) (offset + (pfn << PAGE_SHIFT));
360}
3603ab2b 361EXPORT_SYMBOL(__arm_ioremap_pfn);
5924486d 362
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363void __iomem *__arm_ioremap_pfn_caller(unsigned long pfn, unsigned long offset,
364 size_t size, unsigned int mtype, void *caller)
365{
366 return __arm_ioremap_pfn(pfn, offset, size, mtype);
367}
368
9b97173e 369void __iomem *__arm_ioremap(phys_addr_t phys_addr, size_t size,
3603ab2b 370 unsigned int mtype)
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371{
372 return (void __iomem *)phys_addr;
373}
3603ab2b 374EXPORT_SYMBOL(__arm_ioremap);
5924486d 375
9b97173e 376void __iomem * (*arch_ioremap_caller)(phys_addr_t, size_t, unsigned int, void *);
8a2b6255 377
9b97173e 378void __iomem *__arm_ioremap_caller(phys_addr_t phys_addr, size_t size,
b1a9ceb2 379 unsigned int mtype, void *caller)
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380{
381 return __arm_ioremap(phys_addr, size, mtype);
382}
383
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384void (*arch_iounmap)(volatile void __iomem *);
385
386void __arm_iounmap(volatile void __iomem *addr)
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387{
388}
8a2b6255 389EXPORT_SYMBOL(__arm_iounmap);