git.stricted.de - GitHub/LineageOS/android_kernel_samsung

1 #ifndef _ASM_POWERPC_MMU_H_

2 #define _ASM_POWERPC_MMU_H_

3 #ifdef __KERNEL__

5 #ifndef CONFIG_PPC64

6 #include <asm-ppc/mmu.h>

7 #else

9 /*

10 * PowerPC memory management structures

11 *

12 * Dave Engebretsen & Mike Corrigan <{engebret|mikejc}@us.ibm.com>

13 * PPC64 rework.

14 *

15 * This program is free software; you can redistribute it and/or

16 * modify it under the terms of the GNU General Public License

17 * as published by the Free Software Foundation; either version

18 * 2 of the License, or (at your option) any later version.

19 */

21 #include <asm/asm-compat.h>

22 #include <asm/page.h>

24 /*

25 * Segment table

26 */

28 #define STE_ESID_V 0x80

29 #define STE_ESID_KS 0x20

30 #define STE_ESID_KP 0x10

31 #define STE_ESID_N 0x08

33 #define STE_VSID_SHIFT 12

35 /* Location of cpu0's segment table */

36 #define STAB0_PAGE 0x6

37 #define STAB0_OFFSET (STAB0_PAGE << 12)

38 #define STAB0_PHYS_ADDR (STAB0_OFFSET + PHYSICAL_START)

40 #ifndef __ASSEMBLY__

41 extern char initial_stab[];

42 #endif /* ! __ASSEMBLY */

44 /*

45 * SLB

46 */

48 #define SLB_NUM_BOLTED 3

49 #define SLB_CACHE_ENTRIES 8

51 /* Bits in the SLB ESID word */

52 #define SLB_ESID_V ASM_CONST(0x0000000008000000) /* valid */

54 /* Bits in the SLB VSID word */

55 #define SLB_VSID_SHIFT 12

56 #define SLB_VSID_B ASM_CONST(0xc000000000000000)

57 #define SLB_VSID_B_256M ASM_CONST(0x0000000000000000)

58 #define SLB_VSID_B_1T ASM_CONST(0x4000000000000000)

59 #define SLB_VSID_KS ASM_CONST(0x0000000000000800)

60 #define SLB_VSID_KP ASM_CONST(0x0000000000000400)

61 #define SLB_VSID_N ASM_CONST(0x0000000000000200) /* no-execute */

62 #define SLB_VSID_L ASM_CONST(0x0000000000000100)

63 #define SLB_VSID_C ASM_CONST(0x0000000000000080) /* class */

64 #define SLB_VSID_LP ASM_CONST(0x0000000000000030)

65 #define SLB_VSID_LP_00 ASM_CONST(0x0000000000000000)

66 #define SLB_VSID_LP_01 ASM_CONST(0x0000000000000010)

67 #define SLB_VSID_LP_10 ASM_CONST(0x0000000000000020)

68 #define SLB_VSID_LP_11 ASM_CONST(0x0000000000000030)

69 #define SLB_VSID_LLP (SLB_VSID_L|SLB_VSID_LP)

71 #define SLB_VSID_KERNEL (SLB_VSID_KP)

72 #define SLB_VSID_USER (SLB_VSID_KP|SLB_VSID_KS|SLB_VSID_C)

74 #define SLBIE_C (0x08000000)

76 /*

77 * Hash table

78 */

80 #define HPTES_PER_GROUP 8

82 #define HPTE_V_AVPN_SHIFT 7

83 #define HPTE_V_AVPN ASM_CONST(0xffffffffffffff80)

84 #define HPTE_V_AVPN_VAL(x) (((x) & HPTE_V_AVPN) >> HPTE_V_AVPN_SHIFT)

85 #define HPTE_V_COMPARE(x,y) (!(((x) ^ (y)) & HPTE_V_AVPN))

86 #define HPTE_V_BOLTED ASM_CONST(0x0000000000000010)

87 #define HPTE_V_LOCK ASM_CONST(0x0000000000000008)

88 #define HPTE_V_LARGE ASM_CONST(0x0000000000000004)

89 #define HPTE_V_SECONDARY ASM_CONST(0x0000000000000002)

90 #define HPTE_V_VALID ASM_CONST(0x0000000000000001)

92 #define HPTE_R_PP0 ASM_CONST(0x8000000000000000)

93 #define HPTE_R_TS ASM_CONST(0x4000000000000000)

94 #define HPTE_R_RPN_SHIFT 12

95 #define HPTE_R_RPN ASM_CONST(0x3ffffffffffff000)

96 #define HPTE_R_FLAGS ASM_CONST(0x00000000000003ff)

97 #define HPTE_R_PP ASM_CONST(0x0000000000000003)

98 #define HPTE_R_N ASM_CONST(0x0000000000000004)

99 #define HPTE_R_C ASM_CONST(0x0000000000000080)

100 #define HPTE_R_R ASM_CONST(0x0000000000000100)

101

102 /* Values for PP (assumes Ks=0, Kp=1) */

103 /* pp0 will always be 0 for linux */

104 #define PP_RWXX 0 /* Supervisor read/write, User none */

105 #define PP_RWRX 1 /* Supervisor read/write, User read */

106 #define PP_RWRW 2 /* Supervisor read/write, User read/write */

107 #define PP_RXRX 3 /* Supervisor read, User read */

108

109 #ifndef __ASSEMBLY__

110

111 typedef struct {

112 unsigned long v;

113 unsigned long r;

114 } hpte_t;

115

116 extern hpte_t *htab_address;

117 extern unsigned long htab_size_bytes;

118 extern unsigned long htab_hash_mask;

119

120 /*

121 * Page size definition

122 *

123 * shift : is the "PAGE_SHIFT" value for that page size

124 * sllp : is a bit mask with the value of SLB L || LP to be or'ed

125 * directly to a slbmte "vsid" value

126 * penc : is the HPTE encoding mask for the "LP" field:

127 *

128 */

129 struct mmu_psize_def

130 {

131 unsigned int shift; /* number of bits */

132 unsigned int penc; /* HPTE encoding */

133 unsigned int tlbiel; /* tlbiel supported for that page size */

134 unsigned long avpnm; /* bits to mask out in AVPN in the HPTE */

135 unsigned long sllp; /* SLB L||LP (exact mask to use in slbmte) */

136 };

137

138 #endif /* __ASSEMBLY__ */

139

140 /*

141 * The kernel use the constants below to index in the page sizes array.

142 * The use of fixed constants for this purpose is better for performances

143 * of the low level hash refill handlers.

144 *

145 * A non supported page size has a "shift" field set to 0

146 *

147 * Any new page size being implemented can get a new entry in here. Whether

148 * the kernel will use it or not is a different matter though. The actual page

149 * size used by hugetlbfs is not defined here and may be made variable

150 */

151

152 #define MMU_PAGE_4K 0 /* 4K */

153 #define MMU_PAGE_64K 1 /* 64K */

154 #define MMU_PAGE_64K_AP 2 /* 64K Admixed (in a 4K segment) */

155 #define MMU_PAGE_1M 3 /* 1M */

156 #define MMU_PAGE_16M 4 /* 16M */

157 #define MMU_PAGE_16G 5 /* 16G */

158 #define MMU_PAGE_COUNT 6

159

160 #ifndef __ASSEMBLY__

161

162 /*

163 * The current system page sizes

164 */

165 extern struct mmu_psize_def mmu_psize_defs[MMU_PAGE_COUNT];

166 extern int mmu_linear_psize;

167 extern int mmu_virtual_psize;

168 extern int mmu_vmalloc_psize;

169 extern int mmu_io_psize;

170

171 /*

172 * If the processor supports 64k normal pages but not 64k cache

173 * inhibited pages, we have to be prepared to switch processes

174 * to use 4k pages when they create cache-inhibited mappings.

175 * If this is the case, mmu_ci_restrictions will be set to 1.

176 */

177 extern int mmu_ci_restrictions;

178

179 #ifdef CONFIG_HUGETLB_PAGE

180 /*

181 * The page size index of the huge pages for use by hugetlbfs

182 */

183 extern int mmu_huge_psize;

184

185 #endif /* CONFIG_HUGETLB_PAGE */

186

187 /*

188 * This function sets the AVPN and L fields of the HPTE appropriately

189 * for the page size

190 */

191 static inline unsigned long hpte_encode_v(unsigned long va, int psize)

192 {

193 unsigned long v =

194 v = (va >> 23) & ~(mmu_psize_defs[psize].avpnm);

195 v <<= HPTE_V_AVPN_SHIFT;

196 if (psize != MMU_PAGE_4K)

197 v |= HPTE_V_LARGE;

198 return v;

199 }

200

201 /*

202 * This function sets the ARPN, and LP fields of the HPTE appropriately

203 * for the page size. We assume the pa is already "clean" that is properly

204 * aligned for the requested page size

205 */

206 static inline unsigned long hpte_encode_r(unsigned long pa, int psize)

207 {

208 unsigned long r;

209

210 /* A 4K page needs no special encoding */

211 if (psize == MMU_PAGE_4K)

212 return pa & HPTE_R_RPN;

213 else {

214 unsigned int penc = mmu_psize_defs[psize].penc;

215 unsigned int shift = mmu_psize_defs[psize].shift;

216 return (pa & ~((1ul << shift) - 1)) | (penc << 12);

217 }

218 return r;

219 }

220

221 /*

222 * This hashes a virtual address for a 256Mb segment only for now

223 */

224

225 static inline unsigned long hpt_hash(unsigned long va, unsigned int shift)

226 {

227 return ((va >> 28) & 0x7fffffffffUL) ^ ((va & 0x0fffffffUL) >> shift);

228 }

229

230 extern int __hash_page_4K(unsigned long ea, unsigned long access,

231 unsigned long vsid, pte_t *ptep, unsigned long trap,

232 unsigned int local);

233 extern int __hash_page_64K(unsigned long ea, unsigned long access,

234 unsigned long vsid, pte_t *ptep, unsigned long trap,

235 unsigned int local);

236 struct mm_struct;

237 extern int hash_huge_page(struct mm_struct *mm, unsigned long access,

238 unsigned long ea, unsigned long vsid, int local,

239 unsigned long trap);

240

241 extern int htab_bolt_mapping(unsigned long vstart, unsigned long vend,

242 unsigned long pstart, unsigned long mode,

243 int psize);

244

245 extern void htab_initialize(void);

246 extern void htab_initialize_secondary(void);

247 extern void hpte_init_native(void);

248 extern void hpte_init_lpar(void);

249 extern void hpte_init_iSeries(void);

250 extern void hpte_init_beat(void);

251

252 extern void stabs_alloc(void);

253 extern void slb_initialize(void);

254 extern void slb_flush_and_rebolt(void);

255 extern void stab_initialize(unsigned long stab);

256

257 #endif /* __ASSEMBLY__ */

258

259 /*

260 * VSID allocation

261 *

262 * We first generate a 36-bit "proto-VSID". For kernel addresses this

263 * is equal to the ESID, for user addresses it is:

264 * (context << 15) | (esid & 0x7fff)

265 *

266 * The two forms are distinguishable because the top bit is 0 for user

267 * addresses, whereas the top two bits are 1 for kernel addresses.

268 * Proto-VSIDs with the top two bits equal to 0b10 are reserved for

269 * now.

270 *

271 * The proto-VSIDs are then scrambled into real VSIDs with the

272 * multiplicative hash:

273 *

274 * VSID = (proto-VSID * VSID_MULTIPLIER) % VSID_MODULUS

275 * where VSID_MULTIPLIER = 268435399 = 0xFFFFFC7

276 * VSID_MODULUS = 2^36-1 = 0xFFFFFFFFF

277 *

278 * This scramble is only well defined for proto-VSIDs below

279 * 0xFFFFFFFFF, so both proto-VSID and actual VSID 0xFFFFFFFFF are

280 * reserved. VSID_MULTIPLIER is prime, so in particular it is

281 * co-prime to VSID_MODULUS, making this a 1:1 scrambling function.

282 * Because the modulus is 2^n-1 we can compute it efficiently without

283 * a divide or extra multiply (see below).

284 *

285 * This scheme has several advantages over older methods:

286 *

287 * - We have VSIDs allocated for every kernel address

288 * (i.e. everything above 0xC000000000000000), except the very top

289 * segment, which simplifies several things.

290 *

291 * - We allow for 15 significant bits of ESID and 20 bits of

292 * context for user addresses. i.e. 8T (43 bits) of address space for

293 * up to 1M contexts (although the page table structure and context

294 * allocation will need changes to take advantage of this).

295 *

296 * - The scramble function gives robust scattering in the hash

297 * table (at least based on some initial results). The previous

298 * method was more susceptible to pathological cases giving excessive

299 * hash collisions.

300 */

301 /*

302 * WARNING - If you change these you must make sure the asm

303 * implementations in slb_allocate (slb_low.S), do_stab_bolted

304 * (head.S) and ASM_VSID_SCRAMBLE (below) are changed accordingly.

305 *

306 * You'll also need to change the precomputed VSID values in head.S

307 * which are used by the iSeries firmware.

308 */

309

310 #define VSID_MULTIPLIER ASM_CONST(200730139) /* 28-bit prime */

311 #define VSID_BITS 36

312 #define VSID_MODULUS ((1UL<<VSID_BITS)-1)

313

314 #define CONTEXT_BITS 19

315 #define USER_ESID_BITS 16

316

317 #define USER_VSID_RANGE (1UL << (USER_ESID_BITS + SID_SHIFT))

318

319 /*

320 * This macro generates asm code to compute the VSID scramble

321 * function. Used in slb_allocate() and do_stab_bolted. The function

322 * computed is: (protovsid*VSID_MULTIPLIER) % VSID_MODULUS

323 *

324 * rt = register continaing the proto-VSID and into which the

325 * VSID will be stored

326 * rx = scratch register (clobbered)

327 *

328 * - rt and rx must be different registers

329 * - The answer will end up in the low 36 bits of rt. The higher

330 * bits may contain other garbage, so you may need to mask the

331 * result.

332 */

333 #define ASM_VSID_SCRAMBLE(rt, rx) \

334 lis rx,VSID_MULTIPLIER@h; \

335 ori rx,rx,VSID_MULTIPLIER@l; \

336 mulld rt,rt,rx; /* rt = rt * MULTIPLIER */ \

337 \

338 srdi rx,rt,VSID_BITS; \

339 clrldi rt,rt,(64-VSID_BITS); \

340 add rt,rt,rx; /* add high and low bits */ \

341 /* Now, r3 == VSID (mod 2^36-1), and lies between 0 and \

342 * 2^36-1+2^28-1. That in particular means that if r3 >= \

343 * 2^36-1, then r3+1 has the 2^36 bit set. So, if r3+1 has \

344 * the bit clear, r3 already has the answer we want, if it \

345 * doesn't, the answer is the low 36 bits of r3+1. So in all \

346 * cases the answer is the low 36 bits of (r3 + ((r3+1) >> 36))*/\

347 addi rx,rt,1; \

348 srdi rx,rx,VSID_BITS; /* extract 2^36 bit */ \

349 add rt,rt,rx

350

351

352 #ifndef __ASSEMBLY__

353

354 typedef unsigned long mm_context_id_t;

355

356 typedef struct {

357 mm_context_id_t id;

358 u16 user_psize; /* page size index */

359 u16 sllp; /* SLB entry page size encoding */

360 #ifdef CONFIG_HUGETLB_PAGE

361 u16 low_htlb_areas, high_htlb_areas;

362 #endif

363 unsigned long vdso_base;

364 } mm_context_t;

365

366

367 static inline unsigned long vsid_scramble(unsigned long protovsid)

368 {

369 #if 0

370 /* The code below is equivalent to this function for arguments

371 * < 2^VSID_BITS, which is all this should ever be called

372 * with. However gcc is not clever enough to compute the

373 * modulus (2^n-1) without a second multiply. */

374 return ((protovsid * VSID_MULTIPLIER) % VSID_MODULUS);

375 #else /* 1 */

376 unsigned long x;

377

378 x = protovsid * VSID_MULTIPLIER;

379 x = (x >> VSID_BITS) + (x & VSID_MODULUS);

380 return (x + ((x+1) >> VSID_BITS)) & VSID_MODULUS;

381 #endif /* 1 */

382 }

383

384 /* This is only valid for addresses >= KERNELBASE */

385 static inline unsigned long get_kernel_vsid(unsigned long ea)

386 {

387 return vsid_scramble(ea >> SID_SHIFT);

388 }

389

390 /* This is only valid for user addresses (which are below 2^41) */

391 static inline unsigned long get_vsid(unsigned long context, unsigned long ea)

392 {

393 return vsid_scramble((context << USER_ESID_BITS)

394 | (ea >> SID_SHIFT));

395 }

396

397 #define VSID_SCRAMBLE(pvsid) (((pvsid) * VSID_MULTIPLIER) % VSID_MODULUS)

398 #define KERNEL_VSID(ea) VSID_SCRAMBLE(GET_ESID(ea))

399

400 /* Physical address used by some IO functions */

401 typedef unsigned long phys_addr_t;

402

403

404 #endif /* __ASSEMBLY */

405

406 #endif /* CONFIG_PPC64 */

407 #endif /* __KERNEL__ */

408 #endif /* _ASM_POWERPC_MMU_H_ */