1 files changed, 119 insertions, 0 deletions
diff --git a/arch/powerpc/mm/hugetlbpage-hash64.c b/arch/powerpc/mm/hugetlbpage-hash64.c
new file mode 100644
index 000000000..b320f5097
--- /dev/null
+++ b/arch/powerpc/mm/hugetlbpage-hash64.c
@@ -0,0 +1,119 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * PPC64 Huge TLB Page Support for hash based MMUs (POWER4 and later)
+ *
+ * Copyright (C) 2003 David Gibson, IBM Corporation.
+ *
+ * Based on the IA-32 version:
+ * Copyright (C) 2002, Rohit Seth <rohit.seth@intel.com>
+ */
+
+#include <linux/mm.h>
+#include <linux/hugetlb.h>
+#include <asm/pgtable.h>
+#include <asm/pgalloc.h>
+#include <asm/cacheflush.h>
+#include <asm/machdep.h>
+
+extern long hpte_insert_repeating(unsigned long hash, unsigned long vpn,
+				  unsigned long pa, unsigned long rlags,
+				  unsigned long vflags, int psize, int ssize);
+
+int __hash_page_huge(unsigned long ea, unsigned long access, unsigned long vsid,
+		     pte_t *ptep, unsigned long trap, unsigned long flags,
+		     int ssize, unsigned int shift, unsigned int mmu_psize)
+{
+	real_pte_t rpte;
+	unsigned long vpn;
+	unsigned long old_pte, new_pte;
+	unsigned long rflags, pa, sz;
+	long slot, offset;
+
+	BUG_ON(shift != mmu_psize_defs[mmu_psize].shift);
+
+	/* Search the Linux page table for a match with va */
+	vpn = hpt_vpn(ea, vsid, ssize);
+
+	/* At this point, we have a pte (old_pte) which can be used to build
+	 * or update an HPTE. There are 2 cases:
+	 *
+	 * 1. There is a valid (present) pte with no associated HPTE (this is
+	 *	the most common case)
+	 * 2. There is a valid (present) pte with an associated HPTE. The
+	 *	current values of the pp bits in the HPTE prevent access
+	 *	because we are doing software DIRTY bit management and the
+	 *	page is currently not DIRTY.
+	 */
+
+
+	do {
+		old_pte = pte_val(*ptep);
+		/* If PTE busy, retry the access */
+		if (unlikely(old_pte & H_PAGE_BUSY))
+			return 0;
+		/* If PTE permissions don't match, take page fault */
+		if (unlikely(!check_pte_access(access, old_pte)))
+			return 1;
+
+		/* Try to lock the PTE, add ACCESSED and DIRTY if it was
+		 * a write access */
+		new_pte = old_pte | H_PAGE_BUSY | _PAGE_ACCESSED;
+		if (access & _PAGE_WRITE)
+			new_pte |= _PAGE_DIRTY;
+	} while(!pte_xchg(ptep, __pte(old_pte), __pte(new_pte)));
+
+	rflags = htab_convert_pte_flags(new_pte);
+	if (unlikely(mmu_psize == MMU_PAGE_16G))
+		offset = PTRS_PER_PUD;
+	else
+		offset = PTRS_PER_PMD;
+	rpte = __real_pte(__pte(old_pte), ptep, offset);
+
+	sz = ((1UL) << shift);
+	if (!cpu_has_feature(CPU_FTR_COHERENT_ICACHE))
+		/* No CPU has hugepages but lacks no execute, so we
+		 * don't need to worry about that case */
+		rflags = hash_page_do_lazy_icache(rflags, __pte(old_pte), trap);
+
+	/* Check if pte already has an hpte (case 2) */
+	if (unlikely(old_pte & H_PAGE_HASHPTE)) {
+		/* There MIGHT be an HPTE for this pte */
+		unsigned long gslot;
+
+		gslot = pte_get_hash_gslot(vpn, shift, ssize, rpte, 0);
+		if (mmu_hash_ops.hpte_updatepp(gslot, rflags, vpn, mmu_psize,
+					       mmu_psize, ssize, flags) == -1)
+			old_pte &= ~_PAGE_HPTEFLAGS;
+	}
+
+	if (likely(!(old_pte & H_PAGE_HASHPTE))) {
+		unsigned long hash = hpt_hash(vpn, shift, ssize);
+
+		pa = pte_pfn(__pte(old_pte)) << PAGE_SHIFT;
+
+		/* clear HPTE slot informations in new PTE */
+		new_pte = (new_pte & ~_PAGE_HPTEFLAGS) | H_PAGE_HASHPTE;
+
+		slot = hpte_insert_repeating(hash, vpn, pa, rflags, 0,
+					     mmu_psize, ssize);
+
+		/*
+		 * Hypervisor failure. Restore old pte and return -1
+		 * similar to __hash_page_*
+		 */
+		if (unlikely(slot == -2)) {
+			*ptep = __pte(old_pte);
+			hash_failure_debug(ea, access, vsid, trap, ssize,
+					   mmu_psize, mmu_psize, old_pte);
+			return -1;
+		}
+
+		new_pte |= pte_set_hidx(ptep, rpte, 0, slot, offset);
+	}
+
+	/*
+	 * No need to use ldarx/stdcx here
+	 */
+	*ptep = __pte(new_pte & ~H_PAGE_BUSY);
+	return 0;
+}