powerpc/mm: Split hash MMU specific hugepage code into a new file
This patch separates the parts of hugetlbpage.c which are inherently
specific to the hash MMU into a new hugelbpage-hash64.c file.
Signed-off-by: David Gibson <dwg@au1.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
diff --git a/arch/powerpc/mm/hugetlbpage-hash64.c b/arch/powerpc/mm/hugetlbpage-hash64.c
new file mode 100644
index 0000000..1508ffc
--- /dev/null
+++ b/arch/powerpc/mm/hugetlbpage-hash64.c
@@ -0,0 +1,167 @@
+/*
+ * 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>
+
+/*
+ * Called by asm hashtable.S for doing lazy icache flush
+ */
+static unsigned int hash_huge_page_do_lazy_icache(unsigned long rflags,
+ pte_t pte, int trap, unsigned long sz)
+{
+ struct page *page;
+ int i;
+
+ if (!pfn_valid(pte_pfn(pte)))
+ return rflags;
+
+ page = pte_page(pte);
+
+ /* page is dirty */
+ if (!test_bit(PG_arch_1, &page->flags) && !PageReserved(page)) {
+ if (trap == 0x400) {
+ for (i = 0; i < (sz / PAGE_SIZE); i++)
+ __flush_dcache_icache(page_address(page+i));
+ set_bit(PG_arch_1, &page->flags);
+ } else {
+ rflags |= HPTE_R_N;
+ }
+ }
+ return rflags;
+}
+
+int __hash_page_huge(unsigned long ea, unsigned long access, unsigned long vsid,
+ pte_t *ptep, unsigned long trap, int local, int ssize,
+ unsigned int shift, unsigned int mmu_psize)
+{
+ unsigned long old_pte, new_pte;
+ unsigned long va, rflags, pa, sz;
+ long slot;
+ int err = 1;
+
+ BUG_ON(shift != mmu_psize_defs[mmu_psize].shift);
+
+ /* Search the Linux page table for a match with va */
+ va = hpt_va(ea, vsid, ssize);
+
+ /*
+ * Check the user's access rights to the page. If access should be
+ * prevented then send the problem up to do_page_fault.
+ */
+ if (unlikely(access & ~pte_val(*ptep)))
+ goto out;
+ /*
+ * 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 (old_pte & _PAGE_BUSY)
+ goto out;
+ new_pte = old_pte | _PAGE_BUSY | _PAGE_ACCESSED;
+ } while(old_pte != __cmpxchg_u64((unsigned long *)ptep,
+ old_pte, new_pte));
+
+ rflags = 0x2 | (!(new_pte & _PAGE_RW));
+ /* _PAGE_EXEC -> HW_NO_EXEC since it's inverted */
+ rflags |= ((new_pte & _PAGE_EXEC) ? 0 : HPTE_R_N);
+ 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_huge_page_do_lazy_icache(rflags, __pte(old_pte),
+ trap, sz);
+
+ /* Check if pte already has an hpte (case 2) */
+ if (unlikely(old_pte & _PAGE_HASHPTE)) {
+ /* There MIGHT be an HPTE for this pte */
+ unsigned long hash, slot;
+
+ hash = hpt_hash(va, shift, ssize);
+ if (old_pte & _PAGE_F_SECOND)
+ hash = ~hash;
+ slot = (hash & htab_hash_mask) * HPTES_PER_GROUP;
+ slot += (old_pte & _PAGE_F_GIX) >> 12;
+
+ if (ppc_md.hpte_updatepp(slot, rflags, va, mmu_psize,
+ ssize, local) == -1)
+ old_pte &= ~_PAGE_HPTEFLAGS;
+ }
+
+ if (likely(!(old_pte & _PAGE_HASHPTE))) {
+ unsigned long hash = hpt_hash(va, shift, ssize);
+ unsigned long hpte_group;
+
+ pa = pte_pfn(__pte(old_pte)) << PAGE_SHIFT;
+
+repeat:
+ hpte_group = ((hash & htab_hash_mask) *
+ HPTES_PER_GROUP) & ~0x7UL;
+
+ /* clear HPTE slot informations in new PTE */
+#ifdef CONFIG_PPC_64K_PAGES
+ new_pte = (new_pte & ~_PAGE_HPTEFLAGS) | _PAGE_HPTE_SUB0;
+#else
+ new_pte = (new_pte & ~_PAGE_HPTEFLAGS) | _PAGE_HASHPTE;
+#endif
+ /* Add in WIMG bits */
+ rflags |= (new_pte & (_PAGE_WRITETHRU | _PAGE_NO_CACHE |
+ _PAGE_COHERENT | _PAGE_GUARDED));
+
+ /* Insert into the hash table, primary slot */
+ slot = ppc_md.hpte_insert(hpte_group, va, pa, rflags, 0,
+ mmu_psize, ssize);
+
+ /* Primary is full, try the secondary */
+ if (unlikely(slot == -1)) {
+ hpte_group = ((~hash & htab_hash_mask) *
+ HPTES_PER_GROUP) & ~0x7UL;
+ slot = ppc_md.hpte_insert(hpte_group, va, pa, rflags,
+ HPTE_V_SECONDARY,
+ mmu_psize, ssize);
+ if (slot == -1) {
+ if (mftb() & 0x1)
+ hpte_group = ((hash & htab_hash_mask) *
+ HPTES_PER_GROUP)&~0x7UL;
+
+ ppc_md.hpte_remove(hpte_group);
+ goto repeat;
+ }
+ }
+
+ if (unlikely(slot == -2))
+ panic("hash_huge_page: pte_insert failed\n");
+
+ new_pte |= (slot << 12) & (_PAGE_F_SECOND | _PAGE_F_GIX);
+ }
+
+ /*
+ * No need to use ldarx/stdcx here
+ */
+ *ptep = __pte(new_pte & ~_PAGE_BUSY);
+
+ err = 0;
+
+ out:
+ return err;
+}