patch-2.4.22 linux-2.4.22/arch/sh64/mm/tlb.c

• Lines: 167
• Date: 2003-08-25 04:44:40.000000000 -0700
• Orig file: linux-2.4.21/arch/sh64/mm/tlb.c
• Orig date: 1969-12-31 16:00:00.000000000 -0800

diff -urN linux-2.4.21/arch/sh64/mm/tlb.c linux-2.4.22/arch/sh64/mm/tlb.c
@@ -0,0 +1,166 @@
+/*
+ * arch/sh64/mm/tlb.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 __init 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
+ *
+ * @entry:	Address of TLB slot.
+ *
+ * Free a wired (locked-in) entry in the DTLB.
+ *
+ * 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
+ *
+ * @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).
+ */
+inline void sh64_setup_tlb_slot(unsigned long long config_addr,
+				unsigned long eaddr,
+				unsigned long asid,
+				unsigned long paddr)
+{
+	unsigned long long pteh, ptel;
+
+	/* Sign extension */
+#if (NEFF == 32)
+	pteh = (unsigned long long)(signed long long)(signed long) eaddr;
+#else
+#error "Can't sign extend more than 32 bits yet"
+#endif
+	pteh &= PAGE_MASK;
+	pteh |= (asid << PTEH_ASID_SHIFT) | PTEH_VALID;
+#if (NEFF == 32)
+	ptel = (unsigned long long)(signed long long)(signed long) paddr;
+#else
+#error "Can't sign extend more than 32 bits yet"
+#endif
+	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
+ *
+ * @config_addr:	Address of TLB slot.
+ *
+ * Teardown any existing mapping in the TLB slot @config_addr.
+ */
+inline void sh64_teardown_tlb_slot(unsigned long long config_addr)
+	__attribute__ ((alias("__flush_tlb_slot")));
+