1 files changed, 224 insertions, 0 deletions
diff --git a/arch/sh/mm/tlb-sh5.c b/arch/sh/mm/tlb-sh5.c
new file mode 100644
index 000000000..e4bb2a8e0
--- /dev/null
+++ b/arch/sh/mm/tlb-sh5.c
@@ -0,0 +1,224 @@
+/*
+ * arch/sh/mm/tlb-sh5.c
+ *
+ * Copyright (C) 2003  Paul Mundt <lethal@linux-sh.org>
+ * Copyright (C) 2003  Richard Curnow <richard.curnow@superh.com>
+ *
+ * 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/init.h>
+#include <asm/page.h>
+#include <asm/tlb.h>
+#include <asm/mmu_context.h>
+
+/**
+ * sh64_tlb_init - Perform initial setup for the DTLB and ITLB.
+ */
+int sh64_tlb_init(void)
+{
+	/* Assign some sane DTLB defaults */
+	cpu_data->dtlb.entries	= 64;
+	cpu_data->dtlb.step	= 0x10;
+
+	cpu_data->dtlb.first	= DTLB_FIXED | cpu_data->dtlb.step;
+	cpu_data->dtlb.next	= cpu_data->dtlb.first;
+
+	cpu_data->dtlb.last	= DTLB_FIXED |
+				  ((cpu_data->dtlb.entries - 1) *
+				   cpu_data->dtlb.step);
+
+	/* And again for the ITLB */
+	cpu_data->itlb.entries	= 64;
+	cpu_data->itlb.step	= 0x10;
+
+	cpu_data->itlb.first	= ITLB_FIXED | cpu_data->itlb.step;
+	cpu_data->itlb.next	= cpu_data->itlb.first;
+	cpu_data->itlb.last	= ITLB_FIXED |
+				  ((cpu_data->itlb.entries - 1) *
+				   cpu_data->itlb.step);
+
+	return 0;
+}
+
+/**
+ * sh64_next_free_dtlb_entry - Find the next available DTLB entry
+ */
+unsigned long long sh64_next_free_dtlb_entry(void)
+{
+	return cpu_data->dtlb.next;
+}
+
+/**
+ * sh64_get_wired_dtlb_entry - Allocate a wired (locked-in) entry in the DTLB
+ */
+unsigned long long sh64_get_wired_dtlb_entry(void)
+{
+	unsigned long long entry = sh64_next_free_dtlb_entry();
+
+	cpu_data->dtlb.first += cpu_data->dtlb.step;
+	cpu_data->dtlb.next  += cpu_data->dtlb.step;
+
+	return entry;
+}
+
+/**
+ * sh64_put_wired_dtlb_entry - Free a wired (locked-in) entry in the DTLB.
+ *
+ * @entry:	Address of TLB slot.
+ *
+ * Works like a stack, last one to allocate must be first one to free.
+ */
+int sh64_put_wired_dtlb_entry(unsigned long long entry)
+{
+	__flush_tlb_slot(entry);
+
+	/*
+	 * We don't do any particularly useful tracking of wired entries,
+	 * so this approach works like a stack .. last one to be allocated
+	 * has to be the first one to be freed.
+	 *
+	 * We could potentially load wired entries into a list and work on
+	 * rebalancing the list periodically (which also entails moving the
+	 * contents of a TLB entry) .. though I have a feeling that this is
+	 * more trouble than it's worth.
+	 */
+
+	/*
+	 * Entry must be valid .. we don't want any ITLB addresses!
+	 */
+	if (entry <= DTLB_FIXED)
+		return -EINVAL;
+
+	/*
+	 * Next, check if we're within range to be freed. (ie, must be the
+	 * entry beneath the first 'free' entry!
+	 */
+	if (entry < (cpu_data->dtlb.first - cpu_data->dtlb.step))
+		return -EINVAL;
+
+	/* If we are, then bring this entry back into the list */
+	cpu_data->dtlb.first	-= cpu_data->dtlb.step;
+	cpu_data->dtlb.next	= entry;
+
+	return 0;
+}
+
+/**
+ * sh64_setup_tlb_slot - Load up a translation in a wired slot.
+ *
+ * @config_addr:	Address of TLB slot.
+ * @eaddr:		Virtual address.
+ * @asid:		Address Space Identifier.
+ * @paddr:		Physical address.
+ *
+ * Load up a virtual<->physical translation for @eaddr<->@paddr in the
+ * pre-allocated TLB slot @config_addr (see sh64_get_wired_dtlb_entry).
+ */
+void sh64_setup_tlb_slot(unsigned long long config_addr, unsigned long eaddr,
+			 unsigned long asid, unsigned long paddr)
+{
+	unsigned long long pteh, ptel;
+
+	pteh = neff_sign_extend(eaddr);
+	pteh &= PAGE_MASK;
+	pteh |= (asid << PTEH_ASID_SHIFT) | PTEH_VALID;
+	ptel = neff_sign_extend(paddr);
+	ptel &= PAGE_MASK;
+	ptel |= (_PAGE_CACHABLE | _PAGE_READ | _PAGE_WRITE);
+
+	asm volatile("putcfg %0, 1, %1\n\t"
+			"putcfg %0, 0, %2\n"
+			: : "r" (config_addr), "r" (ptel), "r" (pteh));
+}
+
+/**
+ * sh64_teardown_tlb_slot - Teardown a translation.
+ *
+ * @config_addr:	Address of TLB slot.
+ *
+ * Teardown any existing mapping in the TLB slot @config_addr.
+ */
+void sh64_teardown_tlb_slot(unsigned long long config_addr)
+	__attribute__ ((alias("__flush_tlb_slot")));
+
+static int dtlb_entry;
+static unsigned long long dtlb_entries[64];
+
+void tlb_wire_entry(struct vm_area_struct *vma, unsigned long addr, pte_t pte)
+{
+	unsigned long long entry;
+	unsigned long paddr, flags;
+
+	BUG_ON(dtlb_entry == ARRAY_SIZE(dtlb_entries));
+
+	local_irq_save(flags);
+
+	entry = sh64_get_wired_dtlb_entry();
+	dtlb_entries[dtlb_entry++] = entry;
+
+	paddr = pte_val(pte) & _PAGE_FLAGS_HARDWARE_MASK;
+	paddr &= ~PAGE_MASK;
+
+	sh64_setup_tlb_slot(entry, addr, get_asid(), paddr);
+
+	local_irq_restore(flags);
+}
+
+void tlb_unwire_entry(void)
+{
+	unsigned long long entry;
+	unsigned long flags;
+
+	BUG_ON(!dtlb_entry);
+
+	local_irq_save(flags);
+	entry = dtlb_entries[dtlb_entry--];
+
+	sh64_teardown_tlb_slot(entry);
+	sh64_put_wired_dtlb_entry(entry);
+
+	local_irq_restore(flags);
+}
+
+void __update_tlb(struct vm_area_struct *vma, unsigned long address, pte_t pte)
+{
+	unsigned long long ptel;
+	unsigned long long pteh=0;
+	struct tlb_info *tlbp;
+	unsigned long long next;
+	unsigned int fault_code = get_thread_fault_code();
+
+	/* Get PTEL first */
+	ptel = pte.pte_low;
+
+	/*
+	 * Set PTEH register
+	 */
+	pteh = neff_sign_extend(address & MMU_VPN_MASK);
+
+	/* Set the ASID. */
+	pteh |= get_asid() << PTEH_ASID_SHIFT;
+	pteh |= PTEH_VALID;
+
+	/* Set PTEL register, set_pte has performed the sign extension */
+	ptel &= _PAGE_FLAGS_HARDWARE_MASK; /* drop software flags */
+
+	if (fault_code & FAULT_CODE_ITLB)
+		tlbp = &cpu_data->itlb;
+	else
+		tlbp = &cpu_data->dtlb;
+
+	next = tlbp->next;
+	__flush_tlb_slot(next);
+	asm volatile ("putcfg %0,1,%2\n\n\t"
+		      "putcfg %0,0,%1\n"
+		      :  : "r" (next), "r" (pteh), "r" (ptel) );
+
+	next += TLB_STEP;
+	if (next > tlbp->last)
+		next = tlbp->first;
+	tlbp->next = next;
+}