Initial import

1 files changed, 102 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 000000000..4f4ec2ab4
--- /dev/null
+++ b/arch/powerpc/include/asm/pte-hash64-64k.h
@@ -0,0 +1,102 @@
+/* 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 assembly will be used to insert 64K pages
+ * whether 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 __real_pte
+static inline real_pte_t __real_pte(pte_t pte, pte_t *ptep)
+{
+	real_pte_t rpte;
+
+	rpte.pte = pte;
+	rpte.hidx = 0;
+	if (pte_val(pte) & _PAGE_COMBO) {
+		/*
+		 * Make sure we order the hidx load against the _PAGE_COMBO
+		 * check. The store side ordering is done in __hash_page_4K
+		 */
+		smp_rmb();
+		rpte.hidx = pte_val(*((ptep) + PTRS_PER_PTE));
+	}
+	return rpte;
+}
+
+static inline unsigned long __rpte_to_hidx(real_pte_t rpte, unsigned long index)
+{
+	if ((pte_val(rpte.pte) & _PAGE_COMBO))
+		return (rpte.hidx >> (index<<2)) & 0xf;
+	return (pte_val(rpte.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, vpn, index, shift)	\
+	do {								\
+		unsigned long __end = vpn + (1UL << (PAGE_SHIFT - VPN_SHIFT));	\
+		unsigned __split = (psize == MMU_PAGE_4K ||		\
+				    psize == MMU_PAGE_64K_AP);		\
+		shift = mmu_psize_defs[psize].shift;			\
+		for (index = 0; vpn < __end; index++,			\
+			     vpn += (1L << (shift - VPN_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)				\
+	(WARN_ON(((pfn) >= (1UL << (64 - PTE_RPN_SHIFT)))) ? -EINVAL :	\
+		remap_pfn_range((vma), (addr), (pfn), PAGE_SIZE,	\
+			__pgprot(pgprot_val((prot)) | _PAGE_4K_PFN)))
+
+#endif	/* __ASSEMBLY__ */