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authorBenjamin Herrenschmidt <benh@kernel.crashing.org>2009-12-02 09:28:35 +1100
committerBenjamin Herrenschmidt <benh@kernel.crashing.org>2009-12-02 09:28:35 +1100
commit5a7b4193e564d1611ecf1cd859aed60d5612d78f (patch)
tree8831669121df3d50845718b848d7c6e4bc51be26 /arch/powerpc/include/asm/pte-hash64-64k.h
parent86f9e097f340fd0fbd37afe92bd5453f5a84cbca (diff)
downloadblackbird-op-linux-5a7b4193e564d1611ecf1cd859aed60d5612d78f.tar.gz
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Revert "powerpc/mm: Fix bug in pagetable cache cleanup with CONFIG_PPC_SUBPAGE_PROT"
This reverts commit c045256d146800ea1d741a8e9e377dada6b7e195. It breaks build when CONFIG_PPC_SUBPAGE_PROT is not set. I will commit a fixed version separately Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Diffstat (limited to 'arch/powerpc/include/asm/pte-hash64-64k.h')
-rw-r--r--arch/powerpc/include/asm/pte-hash64-64k.h37
1 files changed, 37 insertions, 0 deletions
diff --git a/arch/powerpc/include/asm/pte-hash64-64k.h b/arch/powerpc/include/asm/pte-hash64-64k.h
index c4490f9c67c4..82b72207c51c 100644
--- a/arch/powerpc/include/asm/pte-hash64-64k.h
+++ b/arch/powerpc/include/asm/pte-hash64-64k.h
@@ -76,4 +76,41 @@
remap_pfn_range((vma), (addr), (pfn), PAGE_SIZE, \
__pgprot(pgprot_val((prot)) | _PAGE_4K_PFN))
+
+#ifdef CONFIG_PPC_SUBPAGE_PROT
+/*
+ * For the sub-page protection option, we extend the PGD with one of
+ * these. Basically we have a 3-level tree, with the top level being
+ * the protptrs array. To optimize speed and memory consumption when
+ * only addresses < 4GB are being protected, pointers to the first
+ * four pages of sub-page protection words are stored in the low_prot
+ * array.
+ * Each page of sub-page protection words protects 1GB (4 bytes
+ * protects 64k). For the 3-level tree, each page of pointers then
+ * protects 8TB.
+ */
+struct subpage_prot_table {
+ unsigned long maxaddr; /* only addresses < this are protected */
+ unsigned int **protptrs[2];
+ unsigned int *low_prot[4];
+};
+
+#undef PGD_TABLE_SIZE
+#define PGD_TABLE_SIZE ((sizeof(pgd_t) << PGD_INDEX_SIZE) + \
+ sizeof(struct subpage_prot_table))
+
+#define SBP_L1_BITS (PAGE_SHIFT - 2)
+#define SBP_L2_BITS (PAGE_SHIFT - 3)
+#define SBP_L1_COUNT (1 << SBP_L1_BITS)
+#define SBP_L2_COUNT (1 << SBP_L2_BITS)
+#define SBP_L2_SHIFT (PAGE_SHIFT + SBP_L1_BITS)
+#define SBP_L3_SHIFT (SBP_L2_SHIFT + SBP_L2_BITS)
+
+extern void subpage_prot_free(pgd_t *pgd);
+
+static inline struct subpage_prot_table *pgd_subpage_prot(pgd_t *pgd)
+{
+ return (struct subpage_prot_table *)(pgd + PTRS_PER_PGD);
+}
+#endif /* CONFIG_PPC_SUBPAGE_PROT */
#endif /* __ASSEMBLY__ */
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