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authorPaul Mundt <lethal@linux-sh.org>2009-05-07 03:38:16 -0400
committerPaul Mundt <lethal@linux-sh.org>2009-05-07 03:38:16 -0400
commitee1acbfabd5270b40ce2cfdc202070b7ca91cdff (patch)
treea2247c699ce56431ddb0abb1ed252ea46781a110 /arch/sh/mm
parent40c8bca76ecaa6b663d403d34f0fcd422bbdbffd (diff)
sh: Handle shm_align_mask also for HAVE_ARCH_UNMAPPED_AREA_TOPDOWN.
Presently shm_align_mask is only looked at for the bottom up case, but we still want this for proper colouring constraints in the topdown case. Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Diffstat (limited to 'arch/sh/mm')
-rw-r--r--arch/sh/mm/mmap.c136
1 files changed, 132 insertions, 4 deletions
diff --git a/arch/sh/mm/mmap.c b/arch/sh/mm/mmap.c
index 931f4d003fa0..1b5fdfb4e0c2 100644
--- a/arch/sh/mm/mmap.c
+++ b/arch/sh/mm/mmap.c
@@ -1,7 +1,7 @@
1/* 1/*
2 * arch/sh/mm/mmap.c 2 * arch/sh/mm/mmap.c
3 * 3 *
4 * Copyright (C) 2008 Paul Mundt 4 * Copyright (C) 2008 - 2009 Paul Mundt
5 * 5 *
6 * This file is subject to the terms and conditions of the GNU General Public 6 * This file is subject to the terms and conditions of the GNU General Public
7 * License. See the file "COPYING" in the main directory of this archive 7 * License. See the file "COPYING" in the main directory of this archive
@@ -21,9 +21,26 @@ EXPORT_SYMBOL(shm_align_mask);
21/* 21/*
22 * To avoid cache aliases, we map the shared page with same color. 22 * To avoid cache aliases, we map the shared page with same color.
23 */ 23 */
24#define COLOUR_ALIGN(addr, pgoff) \ 24static inline unsigned long COLOUR_ALIGN(unsigned long addr,
25 ((((addr) + shm_align_mask) & ~shm_align_mask) + \ 25 unsigned long pgoff)
26 (((pgoff) << PAGE_SHIFT) & shm_align_mask)) 26{
27 unsigned long base = (addr + shm_align_mask) & ~shm_align_mask;
28 unsigned long off = (pgoff << PAGE_SHIFT) & shm_align_mask;
29
30 return base + off;
31}
32
33static inline unsigned long COLOUR_ALIGN_DOWN(unsigned long addr,
34 unsigned long pgoff)
35{
36 unsigned long base = addr & ~shm_align_mask;
37 unsigned long off = (pgoff << PAGE_SHIFT) & shm_align_mask;
38
39 if (base + off <= addr)
40 return base + off;
41
42 return base - off;
43}
27 44
28unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr, 45unsigned long arch_get_unmapped_area(struct file *filp, unsigned long addr,
29 unsigned long len, unsigned long pgoff, unsigned long flags) 46 unsigned long len, unsigned long pgoff, unsigned long flags)
@@ -103,6 +120,117 @@ full_search:
103 addr = COLOUR_ALIGN(addr, pgoff); 120 addr = COLOUR_ALIGN(addr, pgoff);
104 } 121 }
105} 122}
123
124unsigned long
125arch_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
126 const unsigned long len, const unsigned long pgoff,
127 const unsigned long flags)
128{
129 struct vm_area_struct *vma;
130 struct mm_struct *mm = current->mm;
131 unsigned long addr = addr0;
132 int do_colour_align;
133
134 if (flags & MAP_FIXED) {
135 /* We do not accept a shared mapping if it would violate
136 * cache aliasing constraints.
137 */
138 if ((flags & MAP_SHARED) &&
139 ((addr - (pgoff << PAGE_SHIFT)) & shm_align_mask))
140 return -EINVAL;
141 return addr;
142 }
143
144 if (unlikely(len > TASK_SIZE))
145 return -ENOMEM;
146
147 do_colour_align = 0;
148 if (filp || (flags & MAP_SHARED))
149 do_colour_align = 1;
150
151 /* requesting a specific address */
152 if (addr) {
153 if (do_colour_align)
154 addr = COLOUR_ALIGN(addr, pgoff);
155 else
156 addr = PAGE_ALIGN(addr);
157
158 vma = find_vma(mm, addr);
159 if (TASK_SIZE - len >= addr &&
160 (!vma || addr + len <= vma->vm_start))
161 return addr;
162 }
163
164 /* check if free_area_cache is useful for us */
165 if (len <= mm->cached_hole_size) {
166 mm->cached_hole_size = 0;
167 mm->free_area_cache = mm->mmap_base;
168 }
169
170 /* either no address requested or can't fit in requested address hole */
171 addr = mm->free_area_cache;
172 if (do_colour_align) {
173 unsigned long base = COLOUR_ALIGN_DOWN(addr-len, pgoff);
174
175 addr = base + len;
176 }
177
178 /* make sure it can fit in the remaining address space */
179 if (likely(addr > len)) {
180 vma = find_vma(mm, addr-len);
181 if (!vma || addr <= vma->vm_start) {
182 /* remember the address as a hint for next time */
183 return (mm->free_area_cache = addr-len);
184 }
185 }
186
187 if (unlikely(mm->mmap_base < len))
188 goto bottomup;
189
190 addr = mm->mmap_base-len;
191 if (do_colour_align)
192 addr = COLOUR_ALIGN_DOWN(addr, pgoff);
193
194 do {
195 /*
196 * Lookup failure means no vma is above this address,
197 * else if new region fits below vma->vm_start,
198 * return with success:
199 */
200 vma = find_vma(mm, addr);
201 if (likely(!vma || addr+len <= vma->vm_start)) {
202 /* remember the address as a hint for next time */
203 return (mm->free_area_cache = addr);
204 }
205
206 /* remember the largest hole we saw so far */
207 if (addr + mm->cached_hole_size < vma->vm_start)
208 mm->cached_hole_size = vma->vm_start - addr;
209
210 /* try just below the current vma->vm_start */
211 addr = vma->vm_start-len;
212 if (do_colour_align)
213 addr = COLOUR_ALIGN_DOWN(addr, pgoff);
214 } while (likely(len < vma->vm_start));
215
216bottomup:
217 /*
218 * A failed mmap() very likely causes application failure,
219 * so fall back to the bottom-up function here. This scenario
220 * can happen with large stack limits and large mmap()
221 * allocations.
222 */
223 mm->cached_hole_size = ~0UL;
224 mm->free_area_cache = TASK_UNMAPPED_BASE;
225 addr = arch_get_unmapped_area(filp, addr0, len, pgoff, flags);
226 /*
227 * Restore the topdown base:
228 */
229 mm->free_area_cache = mm->mmap_base;
230 mm->cached_hole_size = ~0UL;
231
232 return addr;
233}
106#endif /* CONFIG_MMU */ 234#endif /* CONFIG_MMU */
107 235
108/* 236/*