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authorMatt Porter <mporter@kernel.crashing.org>2005-08-06 10:21:06 -0400
committerLinus Torvalds <torvalds@g5.osdl.org>2005-08-06 12:23:57 -0400
commit021a52ac70802a94e699badb52af9d0fa728d5cd (patch)
tree6fb066dd3cd2e4423bdcfd8fc520a762d4848f27 /include/asm-ppc
parent534afb90a9cd0b9643f62d660c164e1d924f39cf (diff)
[PATCH] ppc32: ppc440 pagetable attributes (comments updates)
Here's an incremental patch with comment updates and some additional grammar cleanups. Signed-off-by: Matt Porter <mporter@kernel.crashing.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'include/asm-ppc')
-rw-r--r--include/asm-ppc/pgtable.h26
1 files changed, 13 insertions, 13 deletions
diff --git a/include/asm-ppc/pgtable.h b/include/asm-ppc/pgtable.h
index c41c7958ea1f..92f30b28b252 100644
--- a/include/asm-ppc/pgtable.h
+++ b/include/asm-ppc/pgtable.h
@@ -227,21 +227,21 @@ extern unsigned long ioremap_bot, ioremap_base;
227 * doesn't support SMP. So we can use this as software bit, like 227 * doesn't support SMP. So we can use this as software bit, like
228 * DIRTY. 228 * DIRTY.
229 * 229 *
230 * PPC Book-E Linux implementation uses PPC HW PTE bit field definition, 230 * With the PPC 44x Linux implementation, the 0-11th LSBs of the PTE are used
231 * even it doesn't have HW PTE. 0-11th LSB of PTE stand for memory 231 * for memory protection related functions (see PTE structure in
232 * protection-related function. (See PTE structure in include/asm-ppc/mmu.h) 232 * include/asm-ppc/mmu.h). The _PAGE_XXX definitions in this file map to the
233 * Definition of _PAGE_XXX in "include/asm-ppc/pagetable.h" stands for 233 * above bits. Note that the bit values are CPU specific, not architecture
234 * above bits. Note that those bits values are CPU dependent, not 234 * specific.
235 * architecture.
236 * 235 *
237 * Kernel PTE entry holds arch-dependent swp_entry structure under certain 236 * The kernel PTE entry holds an arch-dependent swp_entry structure under
238 * situation. In other words, in such situation, some portion of PTE bits 237 * certain situations. In other words, in such situations some portion of
239 * are used as swp_entry. In PPC implementation, 3-24th LSB are shared with 238 * the PTE bits are used as a swp_entry. In the PPC implementation, the
240 * swp_entry, however 0-2nd three LSB still hold protection values. 239 * 3-24th LSB are shared with swp_entry, however the 0-2nd three LSB still
241 * That means three protection bits are reserved for both PTE and SWAP 240 * hold protection values. That means the three protection bits are
242 * entry at the most three LSBs. 241 * reserved for both PTE and SWAP entry at the most significant three
242 * LSBs.
243 * 243 *
244 * There are three protection bits available for SWAP entry; 244 * There are three protection bits available for SWAP entry:
245 * _PAGE_PRESENT 245 * _PAGE_PRESENT
246 * _PAGE_FILE 246 * _PAGE_FILE
247 * _PAGE_HASHPTE (if HW has) 247 * _PAGE_HASHPTE (if HW has)