1 files changed, 115 insertions, 0 deletions

diff --git a/arch/powerpc/include/asm/pte-hash64-64k.h b/arch/powerpc/include/asm/pte-hash64-64k.h
new file mode 100644
index 000000000000..e05d26fa372f
--- /dev/null
+++ b/arch/powerpc/include/asm/pte-hash64-64k.h
@@ -0,0 +1,115 @@
+/* To be include by pgtable-hash64.h only */
+
+/* Additional PTE bits (don't change without checking asm in hash_low.S) */
+#define _PAGE_SPECIAL   0x00000400 /* software: special page */
+#define _PAGE_HPTE_SUB  0x0ffff000 /* combo only: sub pages HPTE bits */
+#define _PAGE_HPTE_SUB0 0x08000000 /* combo only: first sub page */
+#define _PAGE_COMBO     0x10000000 /* this is a combo 4k page */
+#define _PAGE_4K_PFN    0x20000000 /* PFN is for a single 4k page */
+
+/* For 64K page, we don't have a separate _PAGE_HASHPTE bit. Instead,
+ * we set that to be the whole sub-bits mask. The C code will only
+ * test this, so a multi-bit mask will work. For combo pages, this
+ * is equivalent as effectively, the old _PAGE_HASHPTE was an OR of
+ * all the sub bits. For real 64k pages, we now have the assembly set
+ * _PAGE_HPTE_SUB0 in addition to setting the HIDX bits which overlap
+ * that mask. This is fine as long as the HIDX bits are never set on
+ * a PTE that isn't hashed, which is the case today.
+ *
+ * A little nit is for the huge page C code, which does the hashing
+ * in C, we need to provide which bit to use.
+ */
+#define _PAGE_HASHPTE   _PAGE_HPTE_SUB
+
+/* Note the full page bits must be in the same location as for normal
+ * 4k pages as the same asssembly will be used to insert 64K pages
+ * wether the kernel has CONFIG_PPC_64K_PAGES or not
+ */
+#define _PAGE_F_SECOND  0x00008000 /* full page: hidx bits */
+#define _PAGE_F_GIX     0x00007000 /* full page: hidx bits */
+
+/* PTE flags to conserve for HPTE identification */
+#define _PAGE_HPTEFLAGS (_PAGE_BUSY | _PAGE_HASHPTE | _PAGE_COMBO)
+
+/* Shift to put page number into pte.
+ *
+ * That gives us a max RPN of 34 bits, which means a max of 50 bits
+ * of addressable physical space, or 46 bits for the special 4k PFNs.
+ */
+#define PTE_RPN_SHIFT   (30)
+
+#ifndef __ASSEMBLY__
+
+/*
+ * With 64K pages on hash table, we have a special PTE format that
+ * uses a second "half" of the page table to encode sub-page information
+ * in order to deal with 64K made of 4K HW pages. Thus we override the
+ * generic accessors and iterators here
+ */
+#define __real_pte(e,p)         ((real_pte_t) { \
+        (e), pte_val(*((p) + PTRS_PER_PTE)) })
+#define __rpte_to_hidx(r,index) ((pte_val((r).pte) & _PAGE_COMBO) ? \
+        (((r).hidx >> ((index)<<2)) & 0xf) : ((pte_val((r).pte) >> 12) & 0xf))
+#define __rpte_to_pte(r)        ((r).pte)
+#define __rpte_sub_valid(rpte, index) \
+        (pte_val(rpte.pte) & (_PAGE_HPTE_SUB0 >> (index)))
+
+/* Trick: we set __end to va + 64k, which happens works for
+ * a 16M page as well as we want only one iteration
+ */
+#define pte_iterate_hashed_subpages(rpte, psize, va, index, shift)          \
+        do {                                                                \
+                unsigned long __end = va + PAGE_SIZE;                       \
+                unsigned __split = (psize == MMU_PAGE_4K ||                 \
+                                    psize == MMU_PAGE_64K_AP);              \
+                shift = mmu_psize_defs[psize].shift;                        \
+                for (index = 0; va < __end; index++, va += (1L << shift)) { \
+                        if (!__split || __rpte_sub_valid(rpte, index)) do { \
+
+#define pte_iterate_hashed_end() } while(0); } } while(0)
+
+#define pte_pagesize_index(mm, addr, pte)       \
+        (((pte) & _PAGE_COMBO)? MMU_PAGE_4K: MMU_PAGE_64K)
+
+#define remap_4k_pfn(vma, addr, pfn, prot)                              \
+        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__ */