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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * PowerPC64 SLB support.
3 *
4 * Copyright (C) 2004 David Gibson <dwg@au.ibm.com>, IBM
Sankar P5cdcd9d2009-05-12 12:41:13 +05305 * Based on earlier code written by:
Linus Torvalds1da177e2005-04-16 15:20:36 -07006 * Dave Engebretsen and Mike Corrigan {engebret|mikejc}@us.ibm.com
7 * Copyright (c) 2001 Dave Engebretsen
8 * Copyright (C) 2002 Anton Blanchard <anton@au.ibm.com>, IBM
9 *
10 *
11 * This program is free software; you can redistribute it and/or
12 * modify it under the terms of the GNU General Public License
13 * as published by the Free Software Foundation; either version
14 * 2 of the License, or (at your option) any later version.
15 */
16
Linus Torvalds1da177e2005-04-16 15:20:36 -070017#include <asm/pgtable.h>
18#include <asm/mmu.h>
19#include <asm/mmu_context.h>
20#include <asm/paca.h>
21#include <asm/cputable.h>
Benjamin Herrenschmidt3c726f82005-11-07 11:06:55 +110022#include <asm/cacheflush.h>
Michael Neuling2f6093c2006-08-07 16:19:19 +100023#include <asm/smp.h>
24#include <linux/compiler.h>
will schmidtaa39be02007-10-30 06:24:19 +110025#include <asm/udbg.h>
Anton Blanchardb68a70c2011-04-04 23:56:18 +000026#include <asm/code-patching.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070027
Benjamin Herrenschmidt3c726f82005-11-07 11:06:55 +110028
29extern void slb_allocate_realmode(unsigned long ea);
30extern void slb_allocate_user(unsigned long ea);
31
32static void slb_allocate(unsigned long ea)
33{
34 /* Currently, we do real mode for all SLBs including user, but
35 * that will change if we bring back dynamic VSIDs
36 */
37 slb_allocate_realmode(ea);
38}
Linus Torvalds1da177e2005-04-16 15:20:36 -070039
Paul Mackerras3b575062008-05-02 14:29:12 +100040#define slb_esid_mask(ssize) \
41 (((ssize) == MMU_SEGSIZE_256M)? ESID_MASK: ESID_MASK_1T)
42
Paul Mackerras1189be62007-10-11 20:37:10 +100043static inline unsigned long mk_esid_data(unsigned long ea, int ssize,
44 unsigned long slot)
Linus Torvalds1da177e2005-04-16 15:20:36 -070045{
Paul Mackerras3b575062008-05-02 14:29:12 +100046 return (ea & slb_esid_mask(ssize)) | SLB_ESID_V | slot;
Linus Torvalds1da177e2005-04-16 15:20:36 -070047}
48
Paul Mackerras1189be62007-10-11 20:37:10 +100049#define slb_vsid_shift(ssize) \
50 ((ssize) == MMU_SEGSIZE_256M? SLB_VSID_SHIFT: SLB_VSID_SHIFT_1T)
51
52static inline unsigned long mk_vsid_data(unsigned long ea, int ssize,
53 unsigned long flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -070054{
Paul Mackerras1189be62007-10-11 20:37:10 +100055 return (get_kernel_vsid(ea, ssize) << slb_vsid_shift(ssize)) | flags |
56 ((unsigned long) ssize << SLB_VSID_SSIZE_SHIFT);
Linus Torvalds1da177e2005-04-16 15:20:36 -070057}
58
Paul Mackerras1189be62007-10-11 20:37:10 +100059static inline void slb_shadow_update(unsigned long ea, int ssize,
Michael Neuling67439b72007-08-03 11:55:39 +100060 unsigned long flags,
Michael Neuling2f6093c2006-08-07 16:19:19 +100061 unsigned long entry)
Linus Torvalds1da177e2005-04-16 15:20:36 -070062{
Michael Neuling2f6093c2006-08-07 16:19:19 +100063 /*
64 * Clear the ESID first so the entry is not valid while we are
Michael Neuling00efee72007-08-24 16:58:37 +100065 * updating it. No write barriers are needed here, provided
66 * we only update the current CPU's SLB shadow buffer.
Michael Neuling2f6093c2006-08-07 16:19:19 +100067 */
68 get_slb_shadow()->save_area[entry].esid = 0;
Paul Mackerras1189be62007-10-11 20:37:10 +100069 get_slb_shadow()->save_area[entry].vsid = mk_vsid_data(ea, ssize, flags);
70 get_slb_shadow()->save_area[entry].esid = mk_esid_data(ea, ssize, entry);
Michael Neuling2f6093c2006-08-07 16:19:19 +100071}
72
Paul Mackerrasedd06222007-08-10 21:04:07 +100073static inline void slb_shadow_clear(unsigned long entry)
Michael Neuling2f6093c2006-08-07 16:19:19 +100074{
Paul Mackerrasedd06222007-08-10 21:04:07 +100075 get_slb_shadow()->save_area[entry].esid = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -070076}
77
Paul Mackerras1189be62007-10-11 20:37:10 +100078static inline void create_shadowed_slbe(unsigned long ea, int ssize,
79 unsigned long flags,
Paul Mackerras175587c2007-08-25 13:14:28 +100080 unsigned long entry)
81{
82 /*
83 * Updating the shadow buffer before writing the SLB ensures
84 * we don't get a stale entry here if we get preempted by PHYP
85 * between these two statements.
86 */
Paul Mackerras1189be62007-10-11 20:37:10 +100087 slb_shadow_update(ea, ssize, flags, entry);
Paul Mackerras175587c2007-08-25 13:14:28 +100088
89 asm volatile("slbmte %0,%1" :
Paul Mackerras1189be62007-10-11 20:37:10 +100090 : "r" (mk_vsid_data(ea, ssize, flags)),
91 "r" (mk_esid_data(ea, ssize, entry))
Paul Mackerras175587c2007-08-25 13:14:28 +100092 : "memory" );
93}
94
Paul Mackerras9c1e1052009-08-17 15:17:54 +100095static void __slb_flush_and_rebolt(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -070096{
97 /* If you change this make sure you change SLB_NUM_BOLTED
98 * appropriately too. */
Paul Mackerrasbf72aeb2006-06-15 10:45:18 +100099 unsigned long linear_llp, vmalloc_llp, lflags, vflags;
Paul Mackerras1189be62007-10-11 20:37:10 +1000100 unsigned long ksp_esid_data, ksp_vsid_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700101
Benjamin Herrenschmidt3c726f82005-11-07 11:06:55 +1100102 linear_llp = mmu_psize_defs[mmu_linear_psize].sllp;
Paul Mackerrasbf72aeb2006-06-15 10:45:18 +1000103 vmalloc_llp = mmu_psize_defs[mmu_vmalloc_psize].sllp;
Benjamin Herrenschmidt3c726f82005-11-07 11:06:55 +1100104 lflags = SLB_VSID_KERNEL | linear_llp;
Paul Mackerrasbf72aeb2006-06-15 10:45:18 +1000105 vflags = SLB_VSID_KERNEL | vmalloc_llp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106
Paul Mackerras1189be62007-10-11 20:37:10 +1000107 ksp_esid_data = mk_esid_data(get_paca()->kstack, mmu_kernel_ssize, 2);
108 if ((ksp_esid_data & ~0xfffffffUL) <= PAGE_OFFSET) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700109 ksp_esid_data &= ~SLB_ESID_V;
Paul Mackerras1189be62007-10-11 20:37:10 +1000110 ksp_vsid_data = 0;
Paul Mackerrasedd06222007-08-10 21:04:07 +1000111 slb_shadow_clear(2);
112 } else {
113 /* Update stack entry; others don't change */
Paul Mackerras1189be62007-10-11 20:37:10 +1000114 slb_shadow_update(get_paca()->kstack, mmu_kernel_ssize, lflags, 2);
115 ksp_vsid_data = get_slb_shadow()->save_area[2].vsid;
Paul Mackerrasedd06222007-08-10 21:04:07 +1000116 }
Michael Neuling2f6093c2006-08-07 16:19:19 +1000117
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118 /* We need to do this all in asm, so we're sure we don't touch
119 * the stack between the slbia and rebolting it. */
120 asm volatile("isync\n"
121 "slbia\n"
122 /* Slot 1 - first VMALLOC segment */
123 "slbmte %0,%1\n"
124 /* Slot 2 - kernel stack */
125 "slbmte %2,%3\n"
126 "isync"
Paul Mackerras1189be62007-10-11 20:37:10 +1000127 :: "r"(mk_vsid_data(VMALLOC_START, mmu_kernel_ssize, vflags)),
128 "r"(mk_esid_data(VMALLOC_START, mmu_kernel_ssize, 1)),
129 "r"(ksp_vsid_data),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130 "r"(ksp_esid_data)
131 : "memory");
132}
133
Paul Mackerras9c1e1052009-08-17 15:17:54 +1000134void slb_flush_and_rebolt(void)
135{
136
137 WARN_ON(!irqs_disabled());
138
139 /*
140 * We can't take a PMU exception in the following code, so hard
141 * disable interrupts.
142 */
143 hard_irq_disable();
144
145 __slb_flush_and_rebolt();
146 get_paca()->slb_cache_ptr = 0;
147}
148
Michael Neuling67439b72007-08-03 11:55:39 +1000149void slb_vmalloc_update(void)
150{
151 unsigned long vflags;
152
153 vflags = SLB_VSID_KERNEL | mmu_psize_defs[mmu_vmalloc_psize].sllp;
Paul Mackerras1189be62007-10-11 20:37:10 +1000154 slb_shadow_update(VMALLOC_START, mmu_kernel_ssize, vflags, 1);
Michael Neuling67439b72007-08-03 11:55:39 +1000155 slb_flush_and_rebolt();
156}
157
will schmidt465ccab2007-10-31 05:59:33 +1100158/* Helper function to compare esids. There are four cases to handle.
159 * 1. The system is not 1T segment size capable. Use the GET_ESID compare.
160 * 2. The system is 1T capable, both addresses are < 1T, use the GET_ESID compare.
161 * 3. The system is 1T capable, only one of the two addresses is > 1T. This is not a match.
162 * 4. The system is 1T capable, both addresses are > 1T, use the GET_ESID_1T macro to compare.
163 */
164static inline int esids_match(unsigned long addr1, unsigned long addr2)
165{
166 int esid_1t_count;
167
168 /* System is not 1T segment size capable. */
Matt Evans44ae3ab2011-04-06 19:48:50 +0000169 if (!mmu_has_feature(MMU_FTR_1T_SEGMENT))
will schmidt465ccab2007-10-31 05:59:33 +1100170 return (GET_ESID(addr1) == GET_ESID(addr2));
171
172 esid_1t_count = (((addr1 >> SID_SHIFT_1T) != 0) +
173 ((addr2 >> SID_SHIFT_1T) != 0));
174
175 /* both addresses are < 1T */
176 if (esid_1t_count == 0)
177 return (GET_ESID(addr1) == GET_ESID(addr2));
178
179 /* One address < 1T, the other > 1T. Not a match */
180 if (esid_1t_count == 1)
181 return 0;
182
183 /* Both addresses are > 1T. */
184 return (GET_ESID_1T(addr1) == GET_ESID_1T(addr2));
185}
186
Linus Torvalds1da177e2005-04-16 15:20:36 -0700187/* Flush all user entries from the segment table of the current processor. */
188void switch_slb(struct task_struct *tsk, struct mm_struct *mm)
189{
Paul Mackerras9c1e1052009-08-17 15:17:54 +1000190 unsigned long offset;
Paul Mackerras1189be62007-10-11 20:37:10 +1000191 unsigned long slbie_data = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192 unsigned long pc = KSTK_EIP(tsk);
193 unsigned long stack = KSTK_ESP(tsk);
Anton Blanchardde4376c2009-07-13 20:53:53 +0000194 unsigned long exec_base;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700195
Paul Mackerras9c1e1052009-08-17 15:17:54 +1000196 /*
197 * We need interrupts hard-disabled here, not just soft-disabled,
198 * so that a PMU interrupt can't occur, which might try to access
199 * user memory (to get a stack trace) and possible cause an SLB miss
200 * which would update the slb_cache/slb_cache_ptr fields in the PACA.
201 */
202 hard_irq_disable();
203 offset = get_paca()->slb_cache_ptr;
Matt Evans44ae3ab2011-04-06 19:48:50 +0000204 if (!mmu_has_feature(MMU_FTR_NO_SLBIE_B) &&
Olof Johanssonf66bce52007-10-16 00:58:59 +1000205 offset <= SLB_CACHE_ENTRIES) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206 int i;
207 asm volatile("isync" : : : "memory");
208 for (i = 0; i < offset; i++) {
Paul Mackerras1189be62007-10-11 20:37:10 +1000209 slbie_data = (unsigned long)get_paca()->slb_cache[i]
210 << SID_SHIFT; /* EA */
211 slbie_data |= user_segment_size(slbie_data)
212 << SLBIE_SSIZE_SHIFT;
213 slbie_data |= SLBIE_C; /* C set for user addresses */
214 asm volatile("slbie %0" : : "r" (slbie_data));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700215 }
216 asm volatile("isync" : : : "memory");
217 } else {
Paul Mackerras9c1e1052009-08-17 15:17:54 +1000218 __slb_flush_and_rebolt();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700219 }
220
221 /* Workaround POWER5 < DD2.1 issue */
222 if (offset == 1 || offset > SLB_CACHE_ENTRIES)
Paul Mackerras1189be62007-10-11 20:37:10 +1000223 asm volatile("slbie %0" : : "r" (slbie_data));
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224
225 get_paca()->slb_cache_ptr = 0;
226 get_paca()->context = mm->context;
227
228 /*
229 * preload some userspace segments into the SLB.
Anton Blanchardde4376c2009-07-13 20:53:53 +0000230 * Almost all 32 and 64bit PowerPC executables are linked at
231 * 0x10000000 so it makes sense to preload this segment.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232 */
Anton Blanchardde4376c2009-07-13 20:53:53 +0000233 exec_base = 0x10000000;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234
Anton Blanchard5eb9bac2009-07-13 20:53:52 +0000235 if (is_kernel_addr(pc) || is_kernel_addr(stack) ||
Anton Blanchardde4376c2009-07-13 20:53:53 +0000236 is_kernel_addr(exec_base))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700237 return;
Anton Blanchard5eb9bac2009-07-13 20:53:52 +0000238
Linus Torvalds1da177e2005-04-16 15:20:36 -0700239 slb_allocate(pc);
240
Anton Blanchard5eb9bac2009-07-13 20:53:52 +0000241 if (!esids_match(pc, stack))
242 slb_allocate(stack);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700243
Anton Blanchardde4376c2009-07-13 20:53:53 +0000244 if (!esids_match(pc, exec_base) &&
245 !esids_match(stack, exec_base))
246 slb_allocate(exec_base);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247}
248
Benjamin Herrenschmidt3c726f82005-11-07 11:06:55 +1100249static inline void patch_slb_encoding(unsigned int *insn_addr,
250 unsigned int immed)
251{
Anton Blanchardb68a70c2011-04-04 23:56:18 +0000252 int insn = (*insn_addr & 0xffff0000) | immed;
253 patch_instruction(insn_addr, insn);
Benjamin Herrenschmidt3c726f82005-11-07 11:06:55 +1100254}
255
Brian King46db2f82009-08-28 12:06:29 +0000256void slb_set_size(u16 size)
257{
258 extern unsigned int *slb_compare_rr_to_size;
259
260 if (mmu_slb_size == size)
261 return;
262
263 mmu_slb_size = size;
264 patch_slb_encoding(slb_compare_rr_to_size, mmu_slb_size);
265}
266
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267void slb_initialize(void)
268{
Paul Mackerrasbf72aeb2006-06-15 10:45:18 +1000269 unsigned long linear_llp, vmalloc_llp, io_llp;
Stephen Rothwell56291e12006-11-14 12:57:38 +1100270 unsigned long lflags, vflags;
Benjamin Herrenschmidt3c726f82005-11-07 11:06:55 +1100271 static int slb_encoding_inited;
272 extern unsigned int *slb_miss_kernel_load_linear;
Paul Mackerrasbf72aeb2006-06-15 10:45:18 +1000273 extern unsigned int *slb_miss_kernel_load_io;
Michael Neuling584f8b72007-12-06 17:24:48 +1100274 extern unsigned int *slb_compare_rr_to_size;
Benjamin Herrenschmidtcec08e72008-04-30 15:41:48 +1000275#ifdef CONFIG_SPARSEMEM_VMEMMAP
276 extern unsigned int *slb_miss_kernel_load_vmemmap;
277 unsigned long vmemmap_llp;
278#endif
Benjamin Herrenschmidt3c726f82005-11-07 11:06:55 +1100279
280 /* Prepare our SLB miss handler based on our page size */
281 linear_llp = mmu_psize_defs[mmu_linear_psize].sllp;
Paul Mackerrasbf72aeb2006-06-15 10:45:18 +1000282 io_llp = mmu_psize_defs[mmu_io_psize].sllp;
283 vmalloc_llp = mmu_psize_defs[mmu_vmalloc_psize].sllp;
284 get_paca()->vmalloc_sllp = SLB_VSID_KERNEL | vmalloc_llp;
Benjamin Herrenschmidtcec08e72008-04-30 15:41:48 +1000285#ifdef CONFIG_SPARSEMEM_VMEMMAP
286 vmemmap_llp = mmu_psize_defs[mmu_vmemmap_psize].sllp;
287#endif
Benjamin Herrenschmidt3c726f82005-11-07 11:06:55 +1100288 if (!slb_encoding_inited) {
289 slb_encoding_inited = 1;
290 patch_slb_encoding(slb_miss_kernel_load_linear,
291 SLB_VSID_KERNEL | linear_llp);
Paul Mackerrasbf72aeb2006-06-15 10:45:18 +1000292 patch_slb_encoding(slb_miss_kernel_load_io,
293 SLB_VSID_KERNEL | io_llp);
Michael Neuling584f8b72007-12-06 17:24:48 +1100294 patch_slb_encoding(slb_compare_rr_to_size,
295 mmu_slb_size);
Benjamin Herrenschmidt3c726f82005-11-07 11:06:55 +1100296
Michael Ellerman651e2dd2009-06-17 18:13:51 +0000297 pr_devel("SLB: linear LLP = %04lx\n", linear_llp);
298 pr_devel("SLB: io LLP = %04lx\n", io_llp);
Benjamin Herrenschmidtcec08e72008-04-30 15:41:48 +1000299
300#ifdef CONFIG_SPARSEMEM_VMEMMAP
301 patch_slb_encoding(slb_miss_kernel_load_vmemmap,
302 SLB_VSID_KERNEL | vmemmap_llp);
Michael Ellerman651e2dd2009-06-17 18:13:51 +0000303 pr_devel("SLB: vmemmap LLP = %04lx\n", vmemmap_llp);
Benjamin Herrenschmidtcec08e72008-04-30 15:41:48 +1000304#endif
Benjamin Herrenschmidt3c726f82005-11-07 11:06:55 +1100305 }
306
Stephen Rothwell56291e12006-11-14 12:57:38 +1100307 get_paca()->stab_rr = SLB_NUM_BOLTED;
308
Benjamin Herrenschmidt3c726f82005-11-07 11:06:55 +1100309 lflags = SLB_VSID_KERNEL | linear_llp;
Paul Mackerrasbf72aeb2006-06-15 10:45:18 +1000310 vflags = SLB_VSID_KERNEL | vmalloc_llp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311
Benjamin Herrenschmidt3c726f82005-11-07 11:06:55 +1100312 /* Invalidate the entire SLB (even slot 0) & all the ERATS */
Paul Mackerras175587c2007-08-25 13:14:28 +1000313 asm volatile("isync":::"memory");
314 asm volatile("slbmte %0,%0"::"r" (0) : "memory");
315 asm volatile("isync; slbia; isync":::"memory");
Paul Mackerras1189be62007-10-11 20:37:10 +1000316 create_shadowed_slbe(PAGE_OFFSET, mmu_kernel_ssize, lflags, 0);
Benjamin Herrenschmidt3c726f82005-11-07 11:06:55 +1100317
Paul Mackerras1189be62007-10-11 20:37:10 +1000318 create_shadowed_slbe(VMALLOC_START, mmu_kernel_ssize, vflags, 1);
Benjamin Herrenschmidt3c726f82005-11-07 11:06:55 +1100319
Paul Mackerras3b575062008-05-02 14:29:12 +1000320 /* For the boot cpu, we're running on the stack in init_thread_union,
321 * which is in the first segment of the linear mapping, and also
322 * get_paca()->kstack hasn't been initialized yet.
323 * For secondary cpus, we need to bolt the kernel stack entry now.
324 */
Paul Mackerrasdfbe0d32008-01-15 17:29:33 +1100325 slb_shadow_clear(2);
Paul Mackerras3b575062008-05-02 14:29:12 +1000326 if (raw_smp_processor_id() != boot_cpuid &&
327 (get_paca()->kstack & slb_esid_mask(mmu_kernel_ssize)) > PAGE_OFFSET)
328 create_shadowed_slbe(get_paca()->kstack,
329 mmu_kernel_ssize, lflags, 2);
Paul Mackerrasdfbe0d32008-01-15 17:29:33 +1100330
Paul Mackerras175587c2007-08-25 13:14:28 +1000331 asm volatile("isync":::"memory");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332}