sh: Split out MMUCR.URB based entry wiring in to shared helper.
Presently this is duplicated between tlb-sh4 and tlb-pteaex. Split the
helpers out in to a generic tlb-urb that can be used by any parts
equipped with MMUCR.URB.
At the same time, move the SH-5 code out-of-line, as we require single
global state for DTLB entry wiring.
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
diff --git a/arch/sh/mm/tlb-urb.c b/arch/sh/mm/tlb-urb.c
new file mode 100644
index 0000000..bb5b909
--- /dev/null
+++ b/arch/sh/mm/tlb-urb.c
@@ -0,0 +1,81 @@
+/*
+ * arch/sh/mm/tlb-urb.c
+ *
+ * TLB entry wiring helpers for URB-equipped parts.
+ *
+ * Copyright (C) 2010 Matt Fleming
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License. See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#include <linux/mm.h>
+#include <linux/io.h>
+#include <asm/tlb.h>
+#include <asm/mmu_context.h>
+
+/*
+ * Load the entry for 'addr' into the TLB and wire the entry.
+ */
+void tlb_wire_entry(struct vm_area_struct *vma, unsigned long addr, pte_t pte)
+{
+ unsigned long status, flags;
+ int urb;
+
+ local_irq_save(flags);
+
+ /* Load the entry into the TLB */
+ __update_tlb(vma, addr, pte);
+
+ /* ... and wire it up. */
+ status = __raw_readl(MMUCR);
+ urb = (status & MMUCR_URB) >> MMUCR_URB_SHIFT;
+ status &= ~MMUCR_URB;
+
+ /*
+ * Make sure we're not trying to wire the last TLB entry slot.
+ */
+ BUG_ON(!--urb);
+
+ urb = urb % MMUCR_URB_NENTRIES;
+
+ status |= (urb << MMUCR_URB_SHIFT);
+ __raw_writel(status, MMUCR);
+ ctrl_barrier();
+
+ local_irq_restore(flags);
+}
+
+/*
+ * Unwire the last wired TLB entry.
+ *
+ * It should also be noted that it is not possible to wire and unwire
+ * TLB entries in an arbitrary order. If you wire TLB entry N, followed
+ * by entry N+1, you must unwire entry N+1 first, then entry N. In this
+ * respect, it works like a stack or LIFO queue.
+ */
+void tlb_unwire_entry(void)
+{
+ unsigned long status, flags;
+ int urb;
+
+ local_irq_save(flags);
+
+ status = __raw_readl(MMUCR);
+ urb = (status & MMUCR_URB) >> MMUCR_URB_SHIFT;
+ status &= ~MMUCR_URB;
+
+ /*
+ * Make sure we're not trying to unwire a TLB entry when none
+ * have been wired.
+ */
+ BUG_ON(urb++ == MMUCR_URB_NENTRIES);
+
+ urb = urb % MMUCR_URB_NENTRIES;
+
+ status |= (urb << MMUCR_URB_SHIFT);
+ __raw_writel(status, MMUCR);
+ ctrl_barrier();
+
+ local_irq_restore(flags);
+}