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authorAndy Whitcroft <apw@shadowen.org>2007-10-16 04:24:17 -0400
committerLinus Torvalds <torvalds@woody.linux-foundation.org>2007-10-16 12:42:51 -0400
commitd29eff7bca60c9ee401d691d4562a4abca8de543 (patch)
tree86715dfec0470a59d3bbad032b3032321f101766
parent46644c2477c58906e95281636d04e9cc42b39352 (diff)
ppc64: SPARSEMEM_VMEMMAP support
Enable virtual memmap support for SPARSEMEM on PPC64 systems. Slice a 16th off the end of the linear mapping space and use that to hold the vmemmap. Uses the same size mapping as uses in the linear 1:1 kernel mapping. [pbadari@gmail.com: fix warning] Signed-off-by: Andy Whitcroft <apw@shadowen.org> Acked-by: Mel Gorman <mel@csn.ul.ie> Cc: Christoph Lameter <clameter@sgi.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--arch/powerpc/Kconfig1
-rw-r--r--arch/powerpc/mm/init_64.c67
-rw-r--r--include/asm-powerpc/pgtable-ppc64.h8
3 files changed, 76 insertions, 0 deletions
diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig
index 037664d496d7..5e001ad588a7 100644
--- a/arch/powerpc/Kconfig
+++ b/arch/powerpc/Kconfig
@@ -295,6 +295,7 @@ config ARCH_FLATMEM_ENABLE
295config ARCH_SPARSEMEM_ENABLE 295config ARCH_SPARSEMEM_ENABLE
296 def_bool y 296 def_bool y
297 depends on PPC64 297 depends on PPC64
298 select SPARSEMEM_VMEMMAP_ENABLE
298 299
299config ARCH_SPARSEMEM_DEFAULT 300config ARCH_SPARSEMEM_DEFAULT
300 def_bool y 301 def_bool y
diff --git a/arch/powerpc/mm/init_64.c b/arch/powerpc/mm/init_64.c
index fa90f6561b9f..29ed495444f5 100644
--- a/arch/powerpc/mm/init_64.c
+++ b/arch/powerpc/mm/init_64.c
@@ -183,3 +183,70 @@ void pgtable_cache_init(void)
183 zero_ctor); 183 zero_ctor);
184 } 184 }
185} 185}
186
187#ifdef CONFIG_SPARSEMEM_VMEMMAP
188/*
189 * Given an address within the vmemmap, determine the pfn of the page that
190 * represents the start of the section it is within. Note that we have to
191 * do this by hand as the proffered address may not be correctly aligned.
192 * Subtraction of non-aligned pointers produces undefined results.
193 */
194unsigned long __meminit vmemmap_section_start(unsigned long page)
195{
196 unsigned long offset = page - ((unsigned long)(vmemmap));
197
198 /* Return the pfn of the start of the section. */
199 return (offset / sizeof(struct page)) & PAGE_SECTION_MASK;
200}
201
202/*
203 * Check if this vmemmap page is already initialised. If any section
204 * which overlaps this vmemmap page is initialised then this page is
205 * initialised already.
206 */
207int __meminit vmemmap_populated(unsigned long start, int page_size)
208{
209 unsigned long end = start + page_size;
210
211 for (; start < end; start += (PAGES_PER_SECTION * sizeof(struct page)))
212 if (pfn_valid(vmemmap_section_start(start)))
213 return 1;
214
215 return 0;
216}
217
218int __meminit vmemmap_populate(struct page *start_page,
219 unsigned long nr_pages, int node)
220{
221 unsigned long mode_rw;
222 unsigned long start = (unsigned long)start_page;
223 unsigned long end = (unsigned long)(start_page + nr_pages);
224 unsigned long page_size = 1 << mmu_psize_defs[mmu_linear_psize].shift;
225
226 mode_rw = _PAGE_ACCESSED | _PAGE_DIRTY | _PAGE_COHERENT | PP_RWXX;
227
228 /* Align to the page size of the linear mapping. */
229 start = _ALIGN_DOWN(start, page_size);
230
231 for (; start < end; start += page_size) {
232 int mapped;
233 void *p;
234
235 if (vmemmap_populated(start, page_size))
236 continue;
237
238 p = vmemmap_alloc_block(page_size, node);
239 if (!p)
240 return -ENOMEM;
241
242 printk(KERN_WARNING "vmemmap %08lx allocated at %p, "
243 "physical %p.\n", start, p, __pa(p));
244
245 mapped = htab_bolt_mapping(start, start + page_size,
246 __pa(p), mode_rw, mmu_linear_psize);
247 BUG_ON(mapped < 0);
248 }
249
250 return 0;
251}
252#endif
diff --git a/include/asm-powerpc/pgtable-ppc64.h b/include/asm-powerpc/pgtable-ppc64.h
index 300f9a199bf2..dd4c26dc57d2 100644
--- a/include/asm-powerpc/pgtable-ppc64.h
+++ b/include/asm-powerpc/pgtable-ppc64.h
@@ -68,6 +68,14 @@
68#define USER_REGION_ID (0UL) 68#define USER_REGION_ID (0UL)
69 69
70/* 70/*
71 * Defines the address of the vmemap area, in the top 16th of the
72 * kernel region.
73 */
74#define VMEMMAP_BASE (ASM_CONST(CONFIG_KERNEL_START) + \
75 (0xfUL << (REGION_SHIFT - 4)))
76#define vmemmap ((struct page *)VMEMMAP_BASE)
77
78/*
71 * Common bits in a linux-style PTE. These match the bits in the 79 * Common bits in a linux-style PTE. These match the bits in the
72 * (hardware-defined) PowerPC PTE as closely as possible. Additional 80 * (hardware-defined) PowerPC PTE as closely as possible. Additional
73 * bits may be defined in pgtable-*.h 81 * bits may be defined in pgtable-*.h