summaryrefslogtreecommitdiffstats
path: root/arch/powerpc/platforms/iseries/htab.c
blob: 431b22767d0684dc3cfe12530237264456caba95 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
/*
 * iSeries hashtable management.
 *	Derived from pSeries_htab.c
 *
 * SMP scalability work:
 *    Copyright (C) 2001 Anton Blanchard <anton@au.ibm.com>, IBM
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version
 * 2 of the License, or (at your option) any later version.
 */
#include <asm/machdep.h>
#include <asm/pgtable.h>
#include <asm/mmu.h>
#include <asm/mmu_context.h>
#include <asm/iSeries/HvCallHpt.h>
#include <asm/abs_addr.h>
#include <linux/spinlock.h>

static spinlock_t iSeries_hlocks[64] __cacheline_aligned_in_smp =
	{ [0 ... 63] = SPIN_LOCK_UNLOCKED};

/*
 * Very primitive algorithm for picking up a lock
 */
static inline void iSeries_hlock(unsigned long slot)
{
	if (slot & 0x8)
		slot = ~slot;
	spin_lock(&iSeries_hlocks[(slot >> 4) & 0x3f]);
}

static inline void iSeries_hunlock(unsigned long slot)
{
	if (slot & 0x8)
		slot = ~slot;
	spin_unlock(&iSeries_hlocks[(slot >> 4) & 0x3f]);
}

static long iSeries_hpte_insert(unsigned long hpte_group, unsigned long va,
				unsigned long prpn, unsigned long vflags,
				unsigned long rflags)
{
	unsigned long arpn;
	long slot;
	hpte_t lhpte;
	int secondary = 0;

	/*
	 * The hypervisor tries both primary and secondary.
	 * If we are being called to insert in the secondary,
	 * it means we have already tried both primary and secondary,
	 * so we return failure immediately.
	 */
	if (vflags & HPTE_V_SECONDARY)
		return -1;

	iSeries_hlock(hpte_group);

	slot = HvCallHpt_findValid(&lhpte, va >> PAGE_SHIFT);
	BUG_ON(lhpte.v & HPTE_V_VALID);

	if (slot == -1)	{ /* No available entry found in either group */
		iSeries_hunlock(hpte_group);
		return -1;
	}

	if (slot < 0) {		/* MSB set means secondary group */
		vflags |= HPTE_V_VALID;
		secondary = 1;
		slot &= 0x7fffffffffffffff;
	}

	arpn = phys_to_abs(prpn << PAGE_SHIFT) >> PAGE_SHIFT;

	lhpte.v = (va >> 23) << HPTE_V_AVPN_SHIFT | vflags | HPTE_V_VALID;
	lhpte.r = (arpn << HPTE_R_RPN_SHIFT) | rflags;

	/* Now fill in the actual HPTE */
	HvCallHpt_addValidate(slot, secondary, &lhpte);

	iSeries_hunlock(hpte_group);

	return (secondary << 3) | (slot & 7);
}

long iSeries_hpte_bolt_or_insert(unsigned long hpte_group,
		unsigned long va, unsigned long prpn, unsigned long vflags,
		unsigned long rflags)
{
	long slot;
	hpte_t lhpte;

	slot = HvCallHpt_findValid(&lhpte, va >> PAGE_SHIFT);

	if (lhpte.v & HPTE_V_VALID) {
		/* Bolt the existing HPTE */
		HvCallHpt_setSwBits(slot, 0x10, 0);
		HvCallHpt_setPp(slot, PP_RWXX);
		return 0;
	}

	return iSeries_hpte_insert(hpte_group, va, prpn, vflags, rflags);
}

static unsigned long iSeries_hpte_getword0(unsigned long slot)
{
	hpte_t hpte;

	HvCallHpt_get(&hpte, slot);
	return hpte.v;
}

static long iSeries_hpte_remove(unsigned long hpte_group)
{
	unsigned long slot_offset;
	int i;
	unsigned long hpte_v;

	/* Pick a random slot to start at */
	slot_offset = mftb() & 0x7;

	iSeries_hlock(hpte_group);

	for (i = 0; i < HPTES_PER_GROUP; i++) {
		hpte_v = iSeries_hpte_getword0(hpte_group + slot_offset);

		if (! (hpte_v & HPTE_V_BOLTED)) {
			HvCallHpt_invalidateSetSwBitsGet(hpte_group +
							 slot_offset, 0, 0);
			iSeries_hunlock(hpte_group);
			return i;
		}

		slot_offset++;
		slot_offset &= 0x7;
	}

	iSeries_hunlock(hpte_group);

	return -1;
}

/*
 * The HyperVisor expects the "flags" argument in this form:
 *	bits  0..59 : reserved
 *	bit      60 : N
 *	bits 61..63 : PP2,PP1,PP0
 */
static long iSeries_hpte_updatepp(unsigned long slot, unsigned long newpp,
				  unsigned long va, int large, int local)
{
	hpte_t hpte;
	unsigned long avpn = va >> 23;

	iSeries_hlock(slot);

	HvCallHpt_get(&hpte, slot);
	if ((HPTE_V_AVPN_VAL(hpte.v) == avpn) && (hpte.v & HPTE_V_VALID)) {
		/*
		 * Hypervisor expects bits as NPPP, which is
		 * different from how they are mapped in our PP.
		 */
		HvCallHpt_setPp(slot, (newpp & 0x3) | ((newpp & 0x4) << 1));
		iSeries_hunlock(slot);
		return 0;
	}
	iSeries_hunlock(slot);

	return -1;
}

/*
 * Functions used to find the PTE for a particular virtual address.
 * Only used during boot when bolting pages.
 *
 * Input : vpn      : virtual page number
 * Output: PTE index within the page table of the entry
 *         -1 on failure
 */
static long iSeries_hpte_find(unsigned long vpn)
{
	hpte_t hpte;
	long slot;

	/*
	 * The HvCallHpt_findValid interface is as follows:
	 * 0xffffffffffffffff : No entry found.
	 * 0x00000000xxxxxxxx : Entry found in primary group, slot x
	 * 0x80000000xxxxxxxx : Entry found in secondary group, slot x
	 */
	slot = HvCallHpt_findValid(&hpte, vpn);
	if (hpte.v & HPTE_V_VALID) {
		if (slot < 0) {
			slot &= 0x7fffffffffffffff;
			slot = -slot;
		}
	} else
		slot = -1;
	return slot;
}

/*
 * Update the page protection bits. Intended to be used to create
 * guard pages for kernel data structures on pages which are bolted
 * in the HPT. Assumes pages being operated on will not be stolen.
 * Does not work on large pages.
 *
 * No need to lock here because we should be the only user.
 */
static void iSeries_hpte_updateboltedpp(unsigned long newpp, unsigned long ea)
{
	unsigned long vsid,va,vpn;
	long slot;

	vsid = get_kernel_vsid(ea);
	va = (vsid << 28) | (ea & 0x0fffffff);
	vpn = va >> PAGE_SHIFT;
	slot = iSeries_hpte_find(vpn);
	if (slot == -1)
		panic("updateboltedpp: Could not find page to bolt\n");
	HvCallHpt_setPp(slot, newpp);
}

static void iSeries_hpte_invalidate(unsigned long slot, unsigned long va,
				    int large, int local)
{
	unsigned long hpte_v;
	unsigned long avpn = va >> 23;
	unsigned long flags;

	local_irq_save(flags);

	iSeries_hlock(slot);

	hpte_v = iSeries_hpte_getword0(slot);

	if ((HPTE_V_AVPN_VAL(hpte_v) == avpn) && (hpte_v & HPTE_V_VALID))
		HvCallHpt_invalidateSetSwBitsGet(slot, 0, 0);

	iSeries_hunlock(slot);

	local_irq_restore(flags);
}

void hpte_init_iSeries(void)
{
	ppc_md.hpte_invalidate	= iSeries_hpte_invalidate;
	ppc_md.hpte_updatepp	= iSeries_hpte_updatepp;
	ppc_md.hpte_updateboltedpp = iSeries_hpte_updateboltedpp;
	ppc_md.hpte_insert	= iSeries_hpte_insert;
	ppc_md.hpte_remove	= iSeries_hpte_remove;

	htab_finish_init();
}