1 /*
2 * iSeries hashtable management.
3 * Derived from pSeries_htab.c
4 *
5 * SMP scalability work:
6 * Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM
7 *
8 * This program is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU General Public License
10 * as published by the Free Software Foundation; either version
11 * 2 of the License, or (at your option) any later version.
12 */
13 #include <asm/machdep.h>
14 #include <asm/pgtable.h>
15 #include <asm/mmu.h>
16 #include <asm/mmu_context.h>
17 #include <asm/abs_addr.h>
18 #include <linux/spinlock.h>
19
20 #include "call_hpt.h"
21
22 static spinlock_t iSeries_hlocks[64] __cacheline_aligned_in_smp;
23
24 /*
25 * Very primitive algorithm for picking up a lock
26 */
iSeries_hlock(unsigned long slot)27 static inline void iSeries_hlock(unsigned long slot)
28 {
29 if (slot & 0x8)
30 slot = ~slot;
31 spin_lock(&iSeries_hlocks[(slot >> 4) & 0x3f]);
32 }
33
iSeries_hunlock(unsigned long slot)34 static inline void iSeries_hunlock(unsigned long slot)
35 {
36 if (slot & 0x8)
37 slot = ~slot;
38 spin_unlock(&iSeries_hlocks[(slot >> 4) & 0x3f]);
39 }
40
iSeries_hpte_insert(unsigned long hpte_group,unsigned long va,unsigned long pa,unsigned long rflags,unsigned long vflags,int psize,int ssize)41 static long iSeries_hpte_insert(unsigned long hpte_group, unsigned long va,
42 unsigned long pa, unsigned long rflags,
43 unsigned long vflags, int psize, int ssize)
44 {
45 long slot;
46 struct hash_pte lhpte;
47 int secondary = 0;
48
49 BUG_ON(psize != MMU_PAGE_4K);
50
51 /*
52 * The hypervisor tries both primary and secondary.
53 * If we are being called to insert in the secondary,
54 * it means we have already tried both primary and secondary,
55 * so we return failure immediately.
56 */
57 if (vflags & HPTE_V_SECONDARY)
58 return -1;
59
60 iSeries_hlock(hpte_group);
61
62 slot = HvCallHpt_findValid(&lhpte, va >> HW_PAGE_SHIFT);
63 if (unlikely(lhpte.v & HPTE_V_VALID)) {
64 if (vflags & HPTE_V_BOLTED) {
65 HvCallHpt_setSwBits(slot, 0x10, 0);
66 HvCallHpt_setPp(slot, PP_RWXX);
67 iSeries_hunlock(hpte_group);
68 if (slot < 0)
69 return 0x8 | (slot & 7);
70 else
71 return slot & 7;
72 }
73 BUG();
74 }
75
76 if (slot == -1) { /* No available entry found in either group */
77 iSeries_hunlock(hpte_group);
78 return -1;
79 }
80
81 if (slot < 0) { /* MSB set means secondary group */
82 vflags |= HPTE_V_SECONDARY;
83 secondary = 1;
84 slot &= 0x7fffffffffffffff;
85 }
86
87
88 lhpte.v = hpte_encode_v(va, MMU_PAGE_4K, MMU_SEGSIZE_256M) |
89 vflags | HPTE_V_VALID;
90 lhpte.r = hpte_encode_r(phys_to_abs(pa), MMU_PAGE_4K) | rflags;
91
92 /* Now fill in the actual HPTE */
93 HvCallHpt_addValidate(slot, secondary, &lhpte);
94
95 iSeries_hunlock(hpte_group);
96
97 return (secondary << 3) | (slot & 7);
98 }
99
iSeries_hpte_getword0(unsigned long slot)100 static unsigned long iSeries_hpte_getword0(unsigned long slot)
101 {
102 struct hash_pte hpte;
103
104 HvCallHpt_get(&hpte, slot);
105 return hpte.v;
106 }
107
iSeries_hpte_remove(unsigned long hpte_group)108 static long iSeries_hpte_remove(unsigned long hpte_group)
109 {
110 unsigned long slot_offset;
111 int i;
112 unsigned long hpte_v;
113
114 /* Pick a random slot to start at */
115 slot_offset = mftb() & 0x7;
116
117 iSeries_hlock(hpte_group);
118
119 for (i = 0; i < HPTES_PER_GROUP; i++) {
120 hpte_v = iSeries_hpte_getword0(hpte_group + slot_offset);
121
122 if (! (hpte_v & HPTE_V_BOLTED)) {
123 HvCallHpt_invalidateSetSwBitsGet(hpte_group +
124 slot_offset, 0, 0);
125 iSeries_hunlock(hpte_group);
126 return i;
127 }
128
129 slot_offset++;
130 slot_offset &= 0x7;
131 }
132
133 iSeries_hunlock(hpte_group);
134
135 return -1;
136 }
137
138 /*
139 * The HyperVisor expects the "flags" argument in this form:
140 * bits 0..59 : reserved
141 * bit 60 : N
142 * bits 61..63 : PP2,PP1,PP0
143 */
iSeries_hpte_updatepp(unsigned long slot,unsigned long newpp,unsigned long va,int psize,int ssize,int local)144 static long iSeries_hpte_updatepp(unsigned long slot, unsigned long newpp,
145 unsigned long va, int psize, int ssize, int local)
146 {
147 struct hash_pte hpte;
148 unsigned long want_v;
149
150 iSeries_hlock(slot);
151
152 HvCallHpt_get(&hpte, slot);
153 want_v = hpte_encode_v(va, MMU_PAGE_4K, MMU_SEGSIZE_256M);
154
155 if (HPTE_V_COMPARE(hpte.v, want_v) && (hpte.v & HPTE_V_VALID)) {
156 /*
157 * Hypervisor expects bits as NPPP, which is
158 * different from how they are mapped in our PP.
159 */
160 HvCallHpt_setPp(slot, (newpp & 0x3) | ((newpp & 0x4) << 1));
161 iSeries_hunlock(slot);
162 return 0;
163 }
164 iSeries_hunlock(slot);
165
166 return -1;
167 }
168
169 /*
170 * Functions used to find the PTE for a particular virtual address.
171 * Only used during boot when bolting pages.
172 *
173 * Input : vpn : virtual page number
174 * Output: PTE index within the page table of the entry
175 * -1 on failure
176 */
iSeries_hpte_find(unsigned long vpn)177 static long iSeries_hpte_find(unsigned long vpn)
178 {
179 struct hash_pte hpte;
180 long slot;
181
182 /*
183 * The HvCallHpt_findValid interface is as follows:
184 * 0xffffffffffffffff : No entry found.
185 * 0x00000000xxxxxxxx : Entry found in primary group, slot x
186 * 0x80000000xxxxxxxx : Entry found in secondary group, slot x
187 */
188 slot = HvCallHpt_findValid(&hpte, vpn);
189 if (hpte.v & HPTE_V_VALID) {
190 if (slot < 0) {
191 slot &= 0x7fffffffffffffff;
192 slot = -slot;
193 }
194 } else
195 slot = -1;
196 return slot;
197 }
198
199 /*
200 * Update the page protection bits. Intended to be used to create
201 * guard pages for kernel data structures on pages which are bolted
202 * in the HPT. Assumes pages being operated on will not be stolen.
203 * Does not work on large pages.
204 *
205 * No need to lock here because we should be the only user.
206 */
iSeries_hpte_updateboltedpp(unsigned long newpp,unsigned long ea,int psize,int ssize)207 static void iSeries_hpte_updateboltedpp(unsigned long newpp, unsigned long ea,
208 int psize, int ssize)
209 {
210 unsigned long vsid,va,vpn;
211 long slot;
212
213 BUG_ON(psize != MMU_PAGE_4K);
214
215 vsid = get_kernel_vsid(ea, MMU_SEGSIZE_256M);
216 va = (vsid << 28) | (ea & 0x0fffffff);
217 vpn = va >> HW_PAGE_SHIFT;
218 slot = iSeries_hpte_find(vpn);
219 if (slot == -1)
220 panic("updateboltedpp: Could not find page to bolt\n");
221 HvCallHpt_setPp(slot, newpp);
222 }
223
iSeries_hpte_invalidate(unsigned long slot,unsigned long va,int psize,int ssize,int local)224 static void iSeries_hpte_invalidate(unsigned long slot, unsigned long va,
225 int psize, int ssize, int local)
226 {
227 unsigned long hpte_v;
228 unsigned long avpn = va >> 23;
229 unsigned long flags;
230
231 local_irq_save(flags);
232
233 iSeries_hlock(slot);
234
235 hpte_v = iSeries_hpte_getword0(slot);
236
237 if ((HPTE_V_AVPN_VAL(hpte_v) == avpn) && (hpte_v & HPTE_V_VALID))
238 HvCallHpt_invalidateSetSwBitsGet(slot, 0, 0);
239
240 iSeries_hunlock(slot);
241
242 local_irq_restore(flags);
243 }
244
hpte_init_iSeries(void)245 void __init hpte_init_iSeries(void)
246 {
247 int i;
248
249 for (i = 0; i < ARRAY_SIZE(iSeries_hlocks); i++)
250 spin_lock_init(&iSeries_hlocks[i]);
251
252 ppc_md.hpte_invalidate = iSeries_hpte_invalidate;
253 ppc_md.hpte_updatepp = iSeries_hpte_updatepp;
254 ppc_md.hpte_updateboltedpp = iSeries_hpte_updateboltedpp;
255 ppc_md.hpte_insert = iSeries_hpte_insert;
256 ppc_md.hpte_remove = iSeries_hpte_remove;
257 }
258