aboutsummaryrefslogtreecommitdiffstats
path: root/arch/powerpc/mm/slb.c
blob: cc22570856af8f84af061763c6bd8bddcbdee360 (plain) (blame)
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
/*
 * PowerPC64 SLB support.
 *
 * Copyright (C) 2004 David Gibson <dwg@au.ibm.com>, IBM
 * Based on earlier code writteh by:
 * Dave Engebretsen and Mike Corrigan {engebret|mikejc}@us.ibm.com
 *    Copyright (c) 2001 Dave Engebretsen
 * Copyright (C) 2002 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.
 */

#undef DEBUG

#include <linux/config.h>
#include <asm/pgtable.h>
#include <asm/mmu.h>
#include <asm/mmu_context.h>
#include <asm/paca.h>
#include <asm/cputable.h>
#include <asm/cacheflush.h>

#ifdef DEBUG
#define DBG(fmt...) udbg_printf(fmt)
#else
#define DBG(fmt...)
#endif

extern void slb_allocate_realmode(unsigned long ea);
extern void slb_allocate_user(unsigned long ea);

static void slb_allocate(unsigned long ea)
{
	/* Currently, we do real mode for all SLBs including user, but
	 * that will change if we bring back dynamic VSIDs
	 */
	slb_allocate_realmode(ea);
}

static inline unsigned long mk_esid_data(unsigned long ea, unsigned long slot)
{
	return (ea & ESID_MASK) | SLB_ESID_V | slot;
}

static inline unsigned long mk_vsid_data(unsigned long ea, unsigned long flags)
{
	return (get_kernel_vsid(ea) << SLB_VSID_SHIFT) | flags;
}

static inline void create_slbe(unsigned long ea, unsigned long flags,
			       unsigned long entry)
{
	asm volatile("slbmte  %0,%1" :
		     : "r" (mk_vsid_data(ea, flags)),
		       "r" (mk_esid_data(ea, entry))
		     : "memory" );
}

static void slb_flush_and_rebolt(void)
{
	/* If you change this make sure you change SLB_NUM_BOLTED
	 * appropriately too. */
	unsigned long linear_llp, virtual_llp, lflags, vflags;
	unsigned long ksp_esid_data;

	WARN_ON(!irqs_disabled());

	linear_llp = mmu_psize_defs[mmu_linear_psize].sllp;
	virtual_llp = mmu_psize_defs[mmu_virtual_psize].sllp;
	lflags = SLB_VSID_KERNEL | linear_llp;
	vflags = SLB_VSID_KERNEL | virtual_llp;

	ksp_esid_data = mk_esid_data(get_paca()->kstack, 2);
	if ((ksp_esid_data & ESID_MASK) == PAGE_OFFSET)
		ksp_esid_data &= ~SLB_ESID_V;

	/* We need to do this all in asm, so we're sure we don't touch
	 * the stack between the slbia and rebolting it. */
	asm volatile("isync\n"
		     "slbia\n"
		     /* Slot 1 - first VMALLOC segment */
		     "slbmte	%0,%1\n"
		     /* Slot 2 - kernel stack */
		     "slbmte	%2,%3\n"
		     "isync"
		     :: "r"(mk_vsid_data(VMALLOCBASE, vflags)),
		        "r"(mk_esid_data(VMALLOCBASE, 1)),
		        "r"(mk_vsid_data(ksp_esid_data, lflags)),
		        "r"(ksp_esid_data)
		     : "memory");
}

/* Flush all user entries from the segment table of the current processor. */
void switch_slb(struct task_struct *tsk, struct mm_struct *mm)
{
	unsigned long offset = get_paca()->slb_cache_ptr;
	unsigned long esid_data = 0;
	unsigned long pc = KSTK_EIP(tsk);
	unsigned long stack = KSTK_ESP(tsk);
	unsigned long unmapped_base;

	if (offset <= SLB_CACHE_ENTRIES) {
		int i;
		asm volatile("isync" : : : "memory");
		for (i = 0; i < offset; i++) {
			esid_data = ((unsigned long)get_paca()->slb_cache[i]
				<< SID_SHIFT) | SLBIE_C;
			asm volatile("slbie %0" : : "r" (esid_data));
		}
		asm volatile("isync" : : : "memory");
	} else {
		slb_flush_and_rebolt();
	}

	/* Workaround POWER5 < DD2.1 issue */
	if (offset == 1 || offset > SLB_CACHE_ENTRIES)
		asm volatile("slbie %0" : : "r" (esid_data));

	get_paca()->slb_cache_ptr = 0;
	get_paca()->context = mm->context;
#ifdef CONFIG_PPC_64K_PAGES
	get_paca()->pgdir = mm->pgd;
#endif /* CONFIG_PPC_64K_PAGES */

	/*
	 * preload some userspace segments into the SLB.
	 */
	if (test_tsk_thread_flag(tsk, TIF_32BIT))
		unmapped_base = TASK_UNMAPPED_BASE_USER32;
	else
		unmapped_base = TASK_UNMAPPED_BASE_USER64;

	if (is_kernel_addr(pc))
		return;
	slb_allocate(pc);

	if (GET_ESID(pc) == GET_ESID(stack))
		return;

	if (is_kernel_addr(stack))
		return;
	slb_allocate(stack);

	if ((GET_ESID(pc) == GET_ESID(unmapped_base))
	    || (GET_ESID(stack) == GET_ESID(unmapped_base)))
		return;

	if (is_kernel_addr(unmapped_base))
		return;
	slb_allocate(unmapped_base);
}

static inline void patch_slb_encoding(unsigned int *insn_addr,
				      unsigned int immed)
{
	/* Assume the instruction had a "0" immediate value, just
	 * "or" in the new value
	 */
	*insn_addr |= immed;
	flush_icache_range((unsigned long)insn_addr, 4+
			   (unsigned long)insn_addr);
}

void slb_initialize(void)
{
	unsigned long linear_llp, virtual_llp;
	static int slb_encoding_inited;
	extern unsigned int *slb_miss_kernel_load_linear;
	extern unsigned int *slb_miss_kernel_load_virtual;
	extern unsigned int *slb_miss_user_load_normal;
#ifdef CONFIG_HUGETLB_PAGE
	extern unsigned int *slb_miss_user_load_huge;
	unsigned long huge_llp;

	huge_llp = mmu_psize_defs[mmu_huge_psize].sllp;
#endif

	/* Prepare our SLB miss handler based on our page size */
	linear_llp = mmu_psize_defs[mmu_linear_psize].sllp;
	virtual_llp = mmu_psize_defs[mmu_virtual_psize].sllp;
	if (!slb_encoding_inited) {
		slb_encoding_inited = 1;
		patch_slb_encoding(slb_miss_kernel_load_linear,
				   SLB_VSID_KERNEL | linear_llp);
		patch_slb_encoding(slb_miss_kernel_load_virtual,
				   SLB_VSID_KERNEL | virtual_llp);
		patch_slb_encoding(slb_miss_user_load_normal,
				   SLB_VSID_USER | virtual_llp);

		DBG("SLB: linear  LLP = %04x\n", linear_llp);
		DBG("SLB: virtual LLP = %04x\n", virtual_llp);
#ifdef CONFIG_HUGETLB_PAGE
		patch_slb_encoding(slb_miss_user_load_huge,
				   SLB_VSID_USER | huge_llp);
		DBG("SLB: huge    LLP = %04x\n", huge_llp);
#endif
	}

	/* On iSeries the bolted entries have already been set up by
	 * the hypervisor from the lparMap data in head.S */
#ifndef CONFIG_PPC_ISERIES
 {
	unsigned long lflags, vflags;

	lflags = SLB_VSID_KERNEL | linear_llp;
	vflags = SLB_VSID_KERNEL | virtual_llp;

	/* Invalidate the entire SLB (even slot 0) & all the ERATS */
	asm volatile("isync":::"memory");
	asm volatile("slbmte  %0,%0"::"r" (0) : "memory");
	asm volatile("isync; slbia; isync":::"memory");
	create_slbe(PAGE_OFFSET, lflags, 0);

	/* VMALLOC space has 4K pages always for now */
	create_slbe(VMALLOCBASE, vflags, 1);

	/* We don't bolt the stack for the time being - we're in boot,
	 * so the stack is in the bolted segment.  By the time it goes
	 * elsewhere, we'll call _switch() which will bolt in the new
	 * one. */
	asm volatile("isync":::"memory");
 }
#endif /* CONFIG_PPC_ISERIES */

	get_paca()->stab_rr = SLB_NUM_BOLTED;
}