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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * PowerPC memory management structures
3 *
4 * Dave Engebretsen & Mike Corrigan <{engebret|mikejc}@us.ibm.com>
5 * PPC64 rework.
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License
9 * as published by the Free Software Foundation; either version
10 * 2 of the License, or (at your option) any later version.
11 */
12
13#ifndef _PPC64_MMU_H_
14#define _PPC64_MMU_H_
15
16#include <linux/config.h>
17#include <asm/page.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070018
David Gibson1f8d4192005-05-05 16:15:13 -070019/*
20 * Segment table
21 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070022
23#define STE_ESID_V 0x80
24#define STE_ESID_KS 0x20
25#define STE_ESID_KP 0x10
26#define STE_ESID_N 0x08
27
28#define STE_VSID_SHIFT 12
29
David Gibson1f8d4192005-05-05 16:15:13 -070030/* Location of cpu0's segment table */
David Gibsonc59c4642005-08-19 14:52:31 +100031#define STAB0_PAGE 0x6
David Gibson1f8d4192005-05-05 16:15:13 -070032#define STAB0_PHYS_ADDR (STAB0_PAGE<<PAGE_SHIFT)
David Gibsonc59c4642005-08-19 14:52:31 +100033
34#ifndef __ASSEMBLY__
35extern char initial_stab[];
36#endif /* ! __ASSEMBLY */
Linus Torvalds1da177e2005-04-16 15:20:36 -070037
David Gibson1f8d4192005-05-05 16:15:13 -070038/*
39 * SLB
40 */
41
42#define SLB_NUM_BOLTED 3
43#define SLB_CACHE_ENTRIES 8
44
45/* Bits in the SLB ESID word */
46#define SLB_ESID_V ASM_CONST(0x0000000008000000) /* valid */
47
48/* Bits in the SLB VSID word */
49#define SLB_VSID_SHIFT 12
50#define SLB_VSID_KS ASM_CONST(0x0000000000000800)
51#define SLB_VSID_KP ASM_CONST(0x0000000000000400)
52#define SLB_VSID_N ASM_CONST(0x0000000000000200) /* no-execute */
Arnd Bergmannfef1c772005-06-23 09:43:37 +100053#define SLB_VSID_L ASM_CONST(0x0000000000000100) /* largepage */
David Gibson1f8d4192005-05-05 16:15:13 -070054#define SLB_VSID_C ASM_CONST(0x0000000000000080) /* class */
Arnd Bergmannfef1c772005-06-23 09:43:37 +100055#define SLB_VSID_LS ASM_CONST(0x0000000000000070) /* size of largepage */
56
David Gibson1f8d4192005-05-05 16:15:13 -070057#define SLB_VSID_KERNEL (SLB_VSID_KP|SLB_VSID_C)
58#define SLB_VSID_USER (SLB_VSID_KP|SLB_VSID_KS)
59
60/*
61 * Hash table
62 */
Linus Torvalds1da177e2005-04-16 15:20:36 -070063
64#define HPTES_PER_GROUP 8
65
David Gibson96e28442005-07-13 01:11:42 -070066#define HPTE_V_AVPN_SHIFT 7
67#define HPTE_V_AVPN ASM_CONST(0xffffffffffffff80)
68#define HPTE_V_AVPN_VAL(x) (((x) & HPTE_V_AVPN) >> HPTE_V_AVPN_SHIFT)
69#define HPTE_V_BOLTED ASM_CONST(0x0000000000000010)
70#define HPTE_V_LOCK ASM_CONST(0x0000000000000008)
71#define HPTE_V_LARGE ASM_CONST(0x0000000000000004)
72#define HPTE_V_SECONDARY ASM_CONST(0x0000000000000002)
73#define HPTE_V_VALID ASM_CONST(0x0000000000000001)
74
75#define HPTE_R_PP0 ASM_CONST(0x8000000000000000)
76#define HPTE_R_TS ASM_CONST(0x4000000000000000)
77#define HPTE_R_RPN_SHIFT 12
78#define HPTE_R_RPN ASM_CONST(0x3ffffffffffff000)
79#define HPTE_R_FLAGS ASM_CONST(0x00000000000003ff)
80#define HPTE_R_PP ASM_CONST(0x0000000000000003)
81
David Gibson1f8d4192005-05-05 16:15:13 -070082/* Values for PP (assumes Ks=0, Kp=1) */
83/* pp0 will always be 0 for linux */
84#define PP_RWXX 0 /* Supervisor read/write, User none */
85#define PP_RWRX 1 /* Supervisor read/write, User read */
86#define PP_RWRW 2 /* Supervisor read/write, User read/write */
87#define PP_RXRX 3 /* Supervisor read, User read */
88
89#ifndef __ASSEMBLY__
90
Linus Torvalds1da177e2005-04-16 15:20:36 -070091typedef struct {
David Gibson96e28442005-07-13 01:11:42 -070092 unsigned long v;
93 unsigned long r;
94} hpte_t;
Linus Torvalds1da177e2005-04-16 15:20:36 -070095
David Gibson96e28442005-07-13 01:11:42 -070096extern hpte_t *htab_address;
97extern unsigned long htab_hash_mask;
Linus Torvalds1da177e2005-04-16 15:20:36 -070098
99static inline unsigned long hpt_hash(unsigned long vpn, int large)
100{
101 unsigned long vsid;
102 unsigned long page;
103
104 if (large) {
105 vsid = vpn >> 4;
106 page = vpn & 0xf;
107 } else {
108 vsid = vpn >> 16;
109 page = vpn & 0xffff;
110 }
111
112 return (vsid & 0x7fffffffffUL) ^ page;
113}
114
115static inline void __tlbie(unsigned long va, int large)
116{
117 /* clear top 16 bits, non SLS segment */
118 va &= ~(0xffffULL << 48);
119
120 if (large) {
121 va &= HPAGE_MASK;
122 asm volatile("tlbie %0,1" : : "r"(va) : "memory");
123 } else {
124 va &= PAGE_MASK;
125 asm volatile("tlbie %0,0" : : "r"(va) : "memory");
126 }
127}
128
129static inline void tlbie(unsigned long va, int large)
130{
131 asm volatile("ptesync": : :"memory");
132 __tlbie(va, large);
133 asm volatile("eieio; tlbsync; ptesync": : :"memory");
134}
135
136static inline void __tlbiel(unsigned long va)
137{
138 /* clear top 16 bits, non SLS segment */
139 va &= ~(0xffffULL << 48);
140 va &= PAGE_MASK;
141
142 /*
143 * Thanks to Alan Modra we are now able to use machine specific
144 * assembly instructions (like tlbiel) by using the gas -many flag.
145 * However we have to support older toolchains so for the moment
146 * we hardwire it.
147 */
148#if 0
149 asm volatile("tlbiel %0" : : "r"(va) : "memory");
150#else
151 asm volatile(".long 0x7c000224 | (%0 << 11)" : : "r"(va) : "memory");
152#endif
153}
154
155static inline void tlbiel(unsigned long va)
156{
157 asm volatile("ptesync": : :"memory");
158 __tlbiel(va);
159 asm volatile("ptesync": : :"memory");
160}
161
David Gibson96e28442005-07-13 01:11:42 -0700162static inline unsigned long slot2va(unsigned long hpte_v, unsigned long slot)
R Sharadaf4c82d52005-06-25 14:58:08 -0700163{
David Gibson96e28442005-07-13 01:11:42 -0700164 unsigned long avpn = HPTE_V_AVPN_VAL(hpte_v);
R Sharadaf4c82d52005-06-25 14:58:08 -0700165 unsigned long va;
166
167 va = avpn << 23;
168
David Gibson96e28442005-07-13 01:11:42 -0700169 if (! (hpte_v & HPTE_V_LARGE)) {
R Sharadaf4c82d52005-06-25 14:58:08 -0700170 unsigned long vpi, pteg;
171
172 pteg = slot / HPTES_PER_GROUP;
David Gibson96e28442005-07-13 01:11:42 -0700173 if (hpte_v & HPTE_V_SECONDARY)
R Sharadaf4c82d52005-06-25 14:58:08 -0700174 pteg = ~pteg;
175
176 vpi = ((va >> 28) ^ pteg) & htab_hash_mask;
177
178 va |= vpi << PAGE_SHIFT;
179 }
180
181 return va;
182}
183
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184/*
185 * Handle a fault by adding an HPTE. If the address can't be determined
186 * to be valid via Linux page tables, return 1. If handled return 0
187 */
188extern int __hash_page(unsigned long ea, unsigned long access,
189 unsigned long vsid, pte_t *ptep, unsigned long trap,
190 int local);
191
192extern void htab_finish_init(void);
193
David Gibson1f8d4192005-05-05 16:15:13 -0700194extern void hpte_init_native(void);
195extern void hpte_init_lpar(void);
196extern void hpte_init_iSeries(void);
197
198extern long pSeries_lpar_hpte_insert(unsigned long hpte_group,
199 unsigned long va, unsigned long prpn,
David Gibson96e28442005-07-13 01:11:42 -0700200 unsigned long vflags,
201 unsigned long rflags);
David Gibson1f8d4192005-05-05 16:15:13 -0700202extern long native_hpte_insert(unsigned long hpte_group, unsigned long va,
David Gibson96e28442005-07-13 01:11:42 -0700203 unsigned long prpn,
204 unsigned long vflags, unsigned long rflags);
David Gibson1f8d4192005-05-05 16:15:13 -0700205
David Gibson533f0812005-07-27 11:44:19 -0700206extern void stabs_alloc(void);
207
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208#endif /* __ASSEMBLY__ */
209
210/*
David Gibson1f8d4192005-05-05 16:15:13 -0700211 * VSID allocation
212 *
213 * We first generate a 36-bit "proto-VSID". For kernel addresses this
214 * is equal to the ESID, for user addresses it is:
215 * (context << 15) | (esid & 0x7fff)
216 *
217 * The two forms are distinguishable because the top bit is 0 for user
218 * addresses, whereas the top two bits are 1 for kernel addresses.
219 * Proto-VSIDs with the top two bits equal to 0b10 are reserved for
220 * now.
221 *
222 * The proto-VSIDs are then scrambled into real VSIDs with the
223 * multiplicative hash:
224 *
225 * VSID = (proto-VSID * VSID_MULTIPLIER) % VSID_MODULUS
226 * where VSID_MULTIPLIER = 268435399 = 0xFFFFFC7
227 * VSID_MODULUS = 2^36-1 = 0xFFFFFFFFF
228 *
229 * This scramble is only well defined for proto-VSIDs below
230 * 0xFFFFFFFFF, so both proto-VSID and actual VSID 0xFFFFFFFFF are
231 * reserved. VSID_MULTIPLIER is prime, so in particular it is
232 * co-prime to VSID_MODULUS, making this a 1:1 scrambling function.
233 * Because the modulus is 2^n-1 we can compute it efficiently without
234 * a divide or extra multiply (see below).
235 *
236 * This scheme has several advantages over older methods:
237 *
238 * - We have VSIDs allocated for every kernel address
239 * (i.e. everything above 0xC000000000000000), except the very top
240 * segment, which simplifies several things.
241 *
242 * - We allow for 15 significant bits of ESID and 20 bits of
243 * context for user addresses. i.e. 8T (43 bits) of address space for
244 * up to 1M contexts (although the page table structure and context
245 * allocation will need changes to take advantage of this).
246 *
247 * - The scramble function gives robust scattering in the hash
248 * table (at least based on some initial results). The previous
249 * method was more susceptible to pathological cases giving excessive
250 * hash collisions.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700251 */
David Gibson1f8d4192005-05-05 16:15:13 -0700252/*
253 * WARNING - If you change these you must make sure the asm
254 * implementations in slb_allocate (slb_low.S), do_stab_bolted
255 * (head.S) and ASM_VSID_SCRAMBLE (below) are changed accordingly.
256 *
257 * You'll also need to change the precomputed VSID values in head.S
258 * which are used by the iSeries firmware.
259 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700260
261#define VSID_MULTIPLIER ASM_CONST(200730139) /* 28-bit prime */
262#define VSID_BITS 36
263#define VSID_MODULUS ((1UL<<VSID_BITS)-1)
264
David Gibsone28f7fa2005-08-05 19:39:06 +1000265#define CONTEXT_BITS 19
266#define USER_ESID_BITS 16
267
268#define USER_VSID_RANGE (1UL << (USER_ESID_BITS + SID_SHIFT))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700269
270/*
271 * This macro generates asm code to compute the VSID scramble
272 * function. Used in slb_allocate() and do_stab_bolted. The function
273 * computed is: (protovsid*VSID_MULTIPLIER) % VSID_MODULUS
274 *
275 * rt = register continaing the proto-VSID and into which the
276 * VSID will be stored
277 * rx = scratch register (clobbered)
278 *
279 * - rt and rx must be different registers
280 * - The answer will end up in the low 36 bits of rt. The higher
281 * bits may contain other garbage, so you may need to mask the
282 * result.
283 */
284#define ASM_VSID_SCRAMBLE(rt, rx) \
285 lis rx,VSID_MULTIPLIER@h; \
286 ori rx,rx,VSID_MULTIPLIER@l; \
287 mulld rt,rt,rx; /* rt = rt * MULTIPLIER */ \
288 \
289 srdi rx,rt,VSID_BITS; \
290 clrldi rt,rt,(64-VSID_BITS); \
291 add rt,rt,rx; /* add high and low bits */ \
292 /* Now, r3 == VSID (mod 2^36-1), and lies between 0 and \
293 * 2^36-1+2^28-1. That in particular means that if r3 >= \
294 * 2^36-1, then r3+1 has the 2^36 bit set. So, if r3+1 has \
295 * the bit clear, r3 already has the answer we want, if it \
296 * doesn't, the answer is the low 36 bits of r3+1. So in all \
297 * cases the answer is the low 36 bits of (r3 + ((r3+1) >> 36))*/\
298 addi rx,rt,1; \
299 srdi rx,rx,VSID_BITS; /* extract 2^36 bit */ \
300 add rt,rt,rx
301
David Gibson1f8d4192005-05-05 16:15:13 -0700302
303#ifndef __ASSEMBLY__
304
305typedef unsigned long mm_context_id_t;
306
307typedef struct {
308 mm_context_id_t id;
309#ifdef CONFIG_HUGETLB_PAGE
David Gibsonc594ada2005-08-11 16:55:21 +1000310 u16 low_htlb_areas, high_htlb_areas;
David Gibson1f8d4192005-05-05 16:15:13 -0700311#endif
312} mm_context_t;
313
314
315static inline unsigned long vsid_scramble(unsigned long protovsid)
316{
317#if 0
318 /* The code below is equivalent to this function for arguments
319 * < 2^VSID_BITS, which is all this should ever be called
320 * with. However gcc is not clever enough to compute the
321 * modulus (2^n-1) without a second multiply. */
322 return ((protovsid * VSID_MULTIPLIER) % VSID_MODULUS);
323#else /* 1 */
324 unsigned long x;
325
326 x = protovsid * VSID_MULTIPLIER;
327 x = (x >> VSID_BITS) + (x & VSID_MODULUS);
328 return (x + ((x+1) >> VSID_BITS)) & VSID_MODULUS;
329#endif /* 1 */
330}
331
332/* This is only valid for addresses >= KERNELBASE */
333static inline unsigned long get_kernel_vsid(unsigned long ea)
334{
335 return vsid_scramble(ea >> SID_SHIFT);
336}
337
338/* This is only valid for user addresses (which are below 2^41) */
339static inline unsigned long get_vsid(unsigned long context, unsigned long ea)
340{
341 return vsid_scramble((context << USER_ESID_BITS)
342 | (ea >> SID_SHIFT));
343}
344
David Gibson488f8492005-07-27 11:44:21 -0700345#define VSID_SCRAMBLE(pvsid) (((pvsid) * VSID_MULTIPLIER) % VSID_MODULUS)
346#define KERNEL_VSID(ea) VSID_SCRAMBLE(GET_ESID(ea))
347
David Gibson1f8d4192005-05-05 16:15:13 -0700348#endif /* __ASSEMBLY */
349
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350#endif /* _PPC64_MMU_H_ */