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