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Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * This file contains the routines for flushing entries from the
3 * TLB and MMU hash table.
4 *
5 * Derived from arch/ppc64/mm/init.c:
6 * Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
7 *
8 * Modifications by Paul Mackerras (PowerMac) (paulus@cs.anu.edu.au)
9 * and Cort Dougan (PReP) (cort@cs.nmt.edu)
10 * Copyright (C) 1996 Paul Mackerras
Linus Torvalds1da177e2005-04-16 15:20:36 -070011 *
12 * Derived from "arch/i386/mm/init.c"
13 * Copyright (C) 1991, 1992, 1993, 1994 Linus Torvalds
14 *
15 * Dave Engebretsen <engebret@us.ibm.com>
16 * Rework for PPC64 port.
17 *
18 * This program is free software; you can redistribute it and/or
19 * modify it under the terms of the GNU General Public License
20 * as published by the Free Software Foundation; either version
21 * 2 of the License, or (at your option) any later version.
22 */
Benjamin Herrenschmidt3c726f82005-11-07 11:06:55 +110023
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <linux/kernel.h>
25#include <linux/mm.h>
26#include <linux/init.h>
27#include <linux/percpu.h>
28#include <linux/hardirq.h>
29#include <asm/pgalloc.h>
30#include <asm/tlbflush.h>
31#include <asm/tlb.h>
Benjamin Herrenschmidt3c726f82005-11-07 11:06:55 +110032#include <asm/bug.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070033
34DEFINE_PER_CPU(struct ppc64_tlb_batch, ppc64_tlb_batch);
35
Linus Torvalds1da177e2005-04-16 15:20:36 -070036/*
Benjamin Herrenschmidta741e672007-04-10 17:09:37 +100037 * A linux PTE was changed and the corresponding hash table entry
38 * neesd to be flushed. This function will either perform the flush
39 * immediately or will batch it up if the current CPU has an active
40 * batch on it.
Linus Torvalds1da177e2005-04-16 15:20:36 -070041 */
Benjamin Herrenschmidta741e672007-04-10 17:09:37 +100042void hpte_need_flush(struct mm_struct *mm, unsigned long addr,
43 pte_t *ptep, unsigned long pte, int huge)
Linus Torvalds1da177e2005-04-16 15:20:36 -070044{
Aneesh Kumar K.V5524a272012-09-10 02:52:50 +000045 unsigned long vpn;
Peter Zijlstraf3425522011-02-24 10:47:32 +000046 struct ppc64_tlb_batch *batch = &get_cpu_var(ppc64_tlb_batch);
Aneesh Kumar K.V5524a272012-09-10 02:52:50 +000047 unsigned long vsid;
Paul Mackerrasbf72aeb2006-06-15 10:45:18 +100048 unsigned int psize;
Paul Mackerras1189be62007-10-11 20:37:10 +100049 int ssize;
Benjamin Herrenschmidta741e672007-04-10 17:09:37 +100050 real_pte_t rpte;
Benjamin Herrenschmidt61b1a942005-09-20 13:52:50 +100051 int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -070052
Linus Torvalds1da177e2005-04-16 15:20:36 -070053 i = batch->index;
54
Benjamin Herrenschmidt16c2d472007-05-08 16:27:28 +100055 /* Get page size (maybe move back to caller).
56 *
57 * NOTE: when using special 64K mappings in 4K environment like
58 * for SPEs, we obtain the page size from the slice, which thus
59 * must still exist (and thus the VMA not reused) at the time
60 * of this call
61 */
Benjamin Herrenschmidt3c726f82005-11-07 11:06:55 +110062 if (huge) {
63#ifdef CONFIG_HUGETLB_PAGE
Joe Perchesd258e642009-06-28 06:26:10 +000064 psize = get_slice_psize(mm, addr);
David Gibson77058e12010-02-08 20:09:03 +000065 /* Mask the address for the correct page size */
66 addr &= ~((1UL << mmu_psize_defs[psize].shift) - 1);
Benjamin Herrenschmidt3c726f82005-11-07 11:06:55 +110067#else
68 BUG();
Benjamin Herrenschmidt16c2d472007-05-08 16:27:28 +100069 psize = pte_pagesize_index(mm, addr, pte); /* shutup gcc */
Benjamin Herrenschmidt3c726f82005-11-07 11:06:55 +110070#endif
David Gibson77058e12010-02-08 20:09:03 +000071 } else {
Benjamin Herrenschmidt16c2d472007-05-08 16:27:28 +100072 psize = pte_pagesize_index(mm, addr, pte);
David Gibson77058e12010-02-08 20:09:03 +000073 /* Mask the address for the standard page size. If we
74 * have a 64k page kernel, but the hardware does not
75 * support 64k pages, this might be different from the
76 * hardware page size encoded in the slice table. */
77 addr &= PAGE_MASK;
78 }
Benjamin Herrenschmidt3c726f82005-11-07 11:06:55 +110079
David Gibsonf71dc172009-10-26 19:24:31 +000080
Benjamin Herrenschmidta741e672007-04-10 17:09:37 +100081 /* Build full vaddr */
82 if (!is_kernel_addr(addr)) {
Paul Mackerras1189be62007-10-11 20:37:10 +100083 ssize = user_segment_size(addr);
84 vsid = get_vsid(mm->context.id, addr, ssize);
Paul Mackerras1189be62007-10-11 20:37:10 +100085 } else {
86 vsid = get_kernel_vsid(addr, mmu_kernel_ssize);
87 ssize = mmu_kernel_ssize;
88 }
Aneesh Kumar K.Vc60ac562013-03-13 03:34:54 +000089 WARN_ON(vsid == 0);
Aneesh Kumar K.V5524a272012-09-10 02:52:50 +000090 vpn = hpt_vpn(addr, vsid, ssize);
Benjamin Herrenschmidta741e672007-04-10 17:09:37 +100091 rpte = __real_pte(__pte(pte), ptep);
92
93 /*
94 * Check if we have an active batch on this CPU. If not, just
95 * flush now and return. For now, we don global invalidates
96 * in that case, might be worth testing the mm cpu mask though
97 * and decide to use local invalidates instead...
98 */
99 if (!batch->active) {
Aneesh Kumar K.V5524a272012-09-10 02:52:50 +0000100 flush_hash_page(vpn, rpte, psize, ssize, 0);
Peter Zijlstraf3425522011-02-24 10:47:32 +0000101 put_cpu_var(ppc64_tlb_batch);
Benjamin Herrenschmidta741e672007-04-10 17:09:37 +1000102 return;
103 }
104
Linus Torvalds1da177e2005-04-16 15:20:36 -0700105 /*
106 * This can happen when we are in the middle of a TLB batch and
107 * we encounter memory pressure (eg copy_page_range when it tries
108 * to allocate a new pte). If we have to reclaim memory and end
109 * up scanning and resetting referenced bits then our batch context
110 * will change mid stream.
Benjamin Herrenschmidt3c726f82005-11-07 11:06:55 +1100111 *
112 * We also need to ensure only one page size is present in a given
113 * batch
Linus Torvalds1da177e2005-04-16 15:20:36 -0700114 */
Paul Mackerras1189be62007-10-11 20:37:10 +1000115 if (i != 0 && (mm != batch->mm || batch->psize != psize ||
116 batch->ssize != ssize)) {
Benjamin Herrenschmidta741e672007-04-10 17:09:37 +1000117 __flush_tlb_pending(batch);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700118 i = 0;
119 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120 if (i == 0) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700121 batch->mm = mm;
Benjamin Herrenschmidt3c726f82005-11-07 11:06:55 +1100122 batch->psize = psize;
Paul Mackerras1189be62007-10-11 20:37:10 +1000123 batch->ssize = ssize;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700124 }
Benjamin Herrenschmidta741e672007-04-10 17:09:37 +1000125 batch->pte[i] = rpte;
Aneesh Kumar K.V5524a272012-09-10 02:52:50 +0000126 batch->vpn[i] = vpn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127 batch->index = ++i;
128 if (i >= PPC64_TLB_BATCH_NR)
Benjamin Herrenschmidta741e672007-04-10 17:09:37 +1000129 __flush_tlb_pending(batch);
Peter Zijlstraf3425522011-02-24 10:47:32 +0000130 put_cpu_var(ppc64_tlb_batch);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131}
132
Benjamin Herrenschmidta741e672007-04-10 17:09:37 +1000133/*
134 * This function is called when terminating an mmu batch or when a batch
135 * is full. It will perform the flush of all the entries currently stored
136 * in a batch.
137 *
138 * Must be called from within some kind of spinlock/non-preempt region...
139 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700140void __flush_tlb_pending(struct ppc64_tlb_batch *batch)
141{
Rusty Russell56aa4122009-03-15 18:16:43 +0000142 const struct cpumask *tmp;
Benjamin Herrenschmidta741e672007-04-10 17:09:37 +1000143 int i, local = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700144
Linus Torvalds1da177e2005-04-16 15:20:36 -0700145 i = batch->index;
Rusty Russell56aa4122009-03-15 18:16:43 +0000146 tmp = cpumask_of(smp_processor_id());
147 if (cpumask_equal(mm_cpumask(batch->mm), tmp))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148 local = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149 if (i == 1)
Aneesh Kumar K.V5524a272012-09-10 02:52:50 +0000150 flush_hash_page(batch->vpn[0], batch->pte[0],
Paul Mackerras1189be62007-10-11 20:37:10 +1000151 batch->psize, batch->ssize, local);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152 else
Benjamin Herrenschmidt61b1a942005-09-20 13:52:50 +1000153 flush_hash_range(i, local);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700154 batch->index = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155}
156
Benjamin Herrenschmidtc7cc58a12009-07-23 23:15:28 +0000157void tlb_flush(struct mmu_gather *tlb)
158{
Peter Zijlstrad6bf29b2011-05-24 17:11:48 -0700159 struct ppc64_tlb_batch *tlbbatch = &get_cpu_var(ppc64_tlb_batch);
Benjamin Herrenschmidtc7cc58a12009-07-23 23:15:28 +0000160
161 /* If there's a TLB batch pending, then we must flush it because the
162 * pages are going to be freed and we really don't want to have a CPU
163 * access a freed page because it has a stale TLB
164 */
165 if (tlbbatch->index)
166 __flush_tlb_pending(tlbbatch);
167
Peter Zijlstrad6bf29b2011-05-24 17:11:48 -0700168 put_cpu_var(ppc64_tlb_batch);
Benjamin Herrenschmidtc7cc58a12009-07-23 23:15:28 +0000169}
170
Benjamin Herrenschmidt3d5134e2007-06-04 15:15:36 +1000171/**
172 * __flush_hash_table_range - Flush all HPTEs for a given address range
173 * from the hash table (and the TLB). But keeps
174 * the linux PTEs intact.
175 *
176 * @mm : mm_struct of the target address space (generally init_mm)
177 * @start : starting address
178 * @end : ending address (not included in the flush)
179 *
180 * This function is mostly to be used by some IO hotplug code in order
181 * to remove all hash entries from a given address range used to map IO
182 * space on a removed PCI-PCI bidge without tearing down the full mapping
183 * since 64K pages may overlap with other bridges when using 64K pages
184 * with 4K HW pages on IO space.
185 *
Stephen Rothwell40b31362013-05-21 13:49:35 +1000186 * Because of that usage pattern, it is implemented for small size rather
187 * than speed.
Benjamin Herrenschmidt3d5134e2007-06-04 15:15:36 +1000188 */
Benjamin Herrenschmidt3d5134e2007-06-04 15:15:36 +1000189void __flush_hash_table_range(struct mm_struct *mm, unsigned long start,
190 unsigned long end)
191{
Aneesh Kumar K.V12bc9f62013-06-20 14:30:18 +0530192 int hugepage_shift;
Benjamin Herrenschmidt3d5134e2007-06-04 15:15:36 +1000193 unsigned long flags;
194
195 start = _ALIGN_DOWN(start, PAGE_SIZE);
196 end = _ALIGN_UP(end, PAGE_SIZE);
197
198 BUG_ON(!mm->pgd);
199
200 /* Note: Normally, we should only ever use a batch within a
201 * PTE locked section. This violates the rule, but will work
202 * since we don't actually modify the PTEs, we just flush the
203 * hash while leaving the PTEs intact (including their reference
204 * to being hashed). This is not the most performance oriented
205 * way to do things but is fine for our needs here.
206 */
207 local_irq_save(flags);
208 arch_enter_lazy_mmu_mode();
209 for (; start < end; start += PAGE_SIZE) {
Aneesh Kumar K.V12bc9f62013-06-20 14:30:18 +0530210 pte_t *ptep = find_linux_pte_or_hugepte(mm->pgd, start,
211 &hugepage_shift);
Benjamin Herrenschmidt3d5134e2007-06-04 15:15:36 +1000212 unsigned long pte;
213
214 if (ptep == NULL)
215 continue;
216 pte = pte_val(*ptep);
217 if (!(pte & _PAGE_HASHPTE))
218 continue;
Aneesh Kumar K.V12bc9f62013-06-20 14:30:18 +0530219 if (unlikely(hugepage_shift && pmd_trans_huge(*(pmd_t *)pte)))
220 hpte_do_hugepage_flush(mm, start, (pmd_t *)pte);
221 else
222 hpte_need_flush(mm, start, ptep, pte, 0);
Benjamin Herrenschmidt3d5134e2007-06-04 15:15:36 +1000223 }
224 arch_leave_lazy_mmu_mode();
225 local_irq_restore(flags);
226}
Aneesh Kumar K.V074c2ea2013-06-20 14:30:15 +0530227
228void flush_tlb_pmd_range(struct mm_struct *mm, pmd_t *pmd, unsigned long addr)
229{
230 pte_t *pte;
231 pte_t *start_pte;
232 unsigned long flags;
233
234 addr = _ALIGN_DOWN(addr, PMD_SIZE);
235 /* Note: Normally, we should only ever use a batch within a
236 * PTE locked section. This violates the rule, but will work
237 * since we don't actually modify the PTEs, we just flush the
238 * hash while leaving the PTEs intact (including their reference
239 * to being hashed). This is not the most performance oriented
240 * way to do things but is fine for our needs here.
241 */
242 local_irq_save(flags);
243 arch_enter_lazy_mmu_mode();
244 start_pte = pte_offset_map(pmd, addr);
245 for (pte = start_pte; pte < start_pte + PTRS_PER_PTE; pte++) {
246 unsigned long pteval = pte_val(*pte);
247 if (pteval & _PAGE_HASHPTE)
248 hpte_need_flush(mm, addr, pte, pteval, 0);
249 addr += PAGE_SIZE;
Benjamin Herrenschmidt3d5134e2007-06-04 15:15:36 +1000250 }
251 arch_leave_lazy_mmu_mode();
252 local_irq_restore(flags);
253}