[PATCH] avr32 architecture

This adds support for the Atmel AVR32 architecture as well as the AT32AP7000
CPU and the AT32STK1000 development board.

AVR32 is a new high-performance 32-bit RISC microprocessor core, designed for
cost-sensitive embedded applications, with particular emphasis on low power
consumption and high code density.  The AVR32 architecture is not binary
compatible with earlier 8-bit AVR architectures.

The AVR32 architecture, including the instruction set, is described by the
AVR32 Architecture Manual, available from

http://www.atmel.com/dyn/resources/prod_documents/doc32000.pdf

The Atmel AT32AP7000 is the first CPU implementing the AVR32 architecture.  It
features a 7-stage pipeline, 16KB instruction and data caches and a full
Memory Management Unit.  It also comes with a large set of integrated
peripherals, many of which are shared with the AT91 ARM-based controllers from
Atmel.

Full data sheet is available from

http://www.atmel.com/dyn/resources/prod_documents/doc32003.pdf

while the CPU core implementation including caches and MMU is documented by
the AVR32 AP Technical Reference, available from

http://www.atmel.com/dyn/resources/prod_documents/doc32001.pdf

Information about the AT32STK1000 development board can be found at

http://www.atmel.com/dyn/products/tools_card.asp?tool_id=3918

including a BSP CD image with an earlier version of this patch, development
tools (binaries and source/patches) and a root filesystem image suitable for
booting from SD card.

Alternatively, there's a preliminary "getting started" guide available at
http://avr32linux.org/twiki/bin/view/Main/GettingStarted which provides links
to the sources and patches you will need in order to set up a cross-compiling
environment for avr32-linux.

This patch, as well as the other patches included with the BSP and the
toolchain patches, is actively supported by Atmel Corporation.

[dmccr@us.ibm.com: Fix more pxx_page macro locations]
[bunk@stusta.de: fix `make defconfig']
Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Signed-off-by: Dave McCracken <dmccr@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 378 insertions, 0 deletions

diff --git a/arch/avr32/mm/tlb.c b/arch/avr32/mm/tlb.c
new file mode 100644
index 0000000..5d0523b
--- /dev/null
+++ b/arch/avr32/mm/tlb.c
@@ -0,0 +1,378 @@
+/*
+ * AVR32 TLB operations
+ *
+ * Copyright (C) 2004-2006 Atmel Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+#include <linux/mm.h>
+
+#include <asm/mmu_context.h>
+
+#define _TLBEHI_I	0x100
+
+void show_dtlb_entry(unsigned int index)
+{
+	unsigned int tlbehi, tlbehi_save, tlbelo, mmucr, mmucr_save, flags;
+
+	local_irq_save(flags);
+	mmucr_save = sysreg_read(MMUCR);
+	tlbehi_save = sysreg_read(TLBEHI);
+	mmucr = mmucr_save & 0x13;
+	mmucr |= index << 14;
+	sysreg_write(MMUCR, mmucr);
+
+	asm volatile("tlbr" : : : "memory");
+	cpu_sync_pipeline();
+
+	tlbehi = sysreg_read(TLBEHI);
+	tlbelo = sysreg_read(TLBELO);
+
+	printk("%2u: %c %c %02x   %05x %05x %o  %o  %c %c %c %c\n",
+	       index,
+	       (tlbehi & 0x200)?'1':'0',
+	       (tlbelo & 0x100)?'1':'0',
+	       (tlbehi & 0xff),
+	       (tlbehi >> 12), (tlbelo >> 12),
+	       (tlbelo >> 4) & 7, (tlbelo >> 2) & 3,
+	       (tlbelo & 0x200)?'1':'0',
+	       (tlbelo & 0x080)?'1':'0',
+	       (tlbelo & 0x001)?'1':'0',
+	       (tlbelo & 0x002)?'1':'0');
+
+	sysreg_write(MMUCR, mmucr_save);
+	sysreg_write(TLBEHI, tlbehi_save);
+	cpu_sync_pipeline();
+	local_irq_restore(flags);
+}
+
+void dump_dtlb(void)
+{
+	unsigned int i;
+
+	printk("ID  V G ASID VPN   PFN   AP SZ C B W D\n");
+	for (i = 0; i < 32; i++)
+		show_dtlb_entry(i);
+}
+
+static unsigned long last_mmucr;
+
+static inline void set_replacement_pointer(unsigned shift)
+{
+	unsigned long mmucr, mmucr_save;
+
+	mmucr = mmucr_save = sysreg_read(MMUCR);
+
+	/* Does this mapping already exist? */
+	__asm__ __volatile__(
+		"	tlbs\n"
+		"	mfsr %0, %1"
+		: "=r"(mmucr)
+		: "i"(SYSREG_MMUCR));
+
+	if (mmucr & SYSREG_BIT(MMUCR_N)) {
+		/* Not found -- pick a not-recently-accessed entry */
+		unsigned long rp;
+		unsigned long tlbar = sysreg_read(TLBARLO);
+
+		rp = 32 - fls(tlbar);
+		if (rp == 32) {
+			rp = 0;
+			sysreg_write(TLBARLO, -1L);
+		}
+
+		mmucr &= 0x13;
+		mmucr |= (rp << shift);
+
+		sysreg_write(MMUCR, mmucr);
+	}
+
+	last_mmucr = mmucr;
+}
+
+static void update_dtlb(unsigned long address, pte_t pte, unsigned long asid)
+{
+	unsigned long vpn;
+
+	vpn = (address & MMU_VPN_MASK) | _TLBEHI_VALID | asid;
+	sysreg_write(TLBEHI, vpn);
+	cpu_sync_pipeline();
+
+	set_replacement_pointer(14);
+
+	sysreg_write(TLBELO, pte_val(pte) & _PAGE_FLAGS_HARDWARE_MASK);
+
+	/* Let's go */
+	asm volatile("nop\n\ttlbw" : : : "memory");
+	cpu_sync_pipeline();
+}
+
+void update_mmu_cache(struct vm_area_struct *vma,
+		      unsigned long address, pte_t pte)
+{
+	unsigned long flags;
+
+	/* ptrace may call this routine */
+	if (vma && current->active_mm != vma->vm_mm)
+		return;
+
+	local_irq_save(flags);
+	update_dtlb(address, pte, get_asid());
+	local_irq_restore(flags);
+}
+
+void __flush_tlb_page(unsigned long asid, unsigned long page)
+{
+	unsigned long mmucr, tlbehi;
+
+	page |= asid;
+	sysreg_write(TLBEHI, page);
+	cpu_sync_pipeline();
+	asm volatile("tlbs");
+	mmucr = sysreg_read(MMUCR);
+
+	if (!(mmucr & SYSREG_BIT(MMUCR_N))) {
+		unsigned long tlbarlo;
+		unsigned long entry;
+
+		/* Clear the "valid" bit */
+		tlbehi = sysreg_read(TLBEHI);
+		tlbehi &= ~_TLBEHI_VALID;
+		sysreg_write(TLBEHI, tlbehi);
+		cpu_sync_pipeline();
+
+		/* mark the entry as "not accessed" */
+		entry = (mmucr >> 14) & 0x3f;
+		tlbarlo = sysreg_read(TLBARLO);
+		tlbarlo |= (0x80000000 >> entry);
+		sysreg_write(TLBARLO, tlbarlo);
+
+		/* update the entry with valid bit clear */
+		asm volatile("tlbw");
+		cpu_sync_pipeline();
+	}
+}
+
+void flush_tlb_page(struct vm_area_struct *vma, unsigned long page)
+{
+	if (vma->vm_mm && vma->vm_mm->context != NO_CONTEXT) {
+		unsigned long flags, asid;
+		unsigned long saved_asid = MMU_NO_ASID;
+
+		asid = vma->vm_mm->context & MMU_CONTEXT_ASID_MASK;
+		page &= PAGE_MASK;
+
+		local_irq_save(flags);
+		if (vma->vm_mm != current->mm) {
+			saved_asid = get_asid();
+			set_asid(asid);
+		}
+
+		__flush_tlb_page(asid, page);
+
+		if (saved_asid != MMU_NO_ASID)
+			set_asid(saved_asid);
+		local_irq_restore(flags);
+	}
+}
+
+void flush_tlb_range(struct vm_area_struct *vma, unsigned long start,
+		     unsigned long end)
+{
+	struct mm_struct *mm = vma->vm_mm;
+
+	if (mm->context != NO_CONTEXT) {
+		unsigned long flags;
+		int size;
+
+		local_irq_save(flags);
+		size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
+		if (size > (MMU_DTLB_ENTRIES / 4)) { /* Too many entries to flush */
+			mm->context = NO_CONTEXT;
+			if (mm == current->mm)
+				activate_context(mm);
+		} else {
+			unsigned long asid = mm->context & MMU_CONTEXT_ASID_MASK;
+			unsigned long saved_asid = MMU_NO_ASID;
+
+			start &= PAGE_MASK;
+			end += (PAGE_SIZE - 1);
+			end &= PAGE_MASK;
+			if (mm != current->mm) {
+				saved_asid = get_asid();
+				set_asid(asid);
+			}
+
+			while (start < end) {
+				__flush_tlb_page(asid, start);
+				start += PAGE_SIZE;
+			}
+			if (saved_asid != MMU_NO_ASID)
+				set_asid(saved_asid);
+		}
+		local_irq_restore(flags);
+	}
+}
+
+/*
+ * TODO: If this is only called for addresses > TASK_SIZE, we can probably
+ * skip the ASID stuff and just use the Global bit...
+ */
+void flush_tlb_kernel_range(unsigned long start, unsigned long end)
+{
+	unsigned long flags;
+	int size;
+
+	local_irq_save(flags);
+	size = (end - start + (PAGE_SIZE - 1)) >> PAGE_SHIFT;
+	if (size > (MMU_DTLB_ENTRIES / 4)) { /* Too many entries to flush */
+		flush_tlb_all();
+	} else {
+		unsigned long asid = init_mm.context & MMU_CONTEXT_ASID_MASK;
+		unsigned long saved_asid = get_asid();
+
+		start &= PAGE_MASK;
+		end += (PAGE_SIZE - 1);
+		end &= PAGE_MASK;
+		set_asid(asid);
+		while (start < end) {
+			__flush_tlb_page(asid, start);
+			start += PAGE_SIZE;
+		}
+		set_asid(saved_asid);
+	}
+	local_irq_restore(flags);
+}
+
+void flush_tlb_mm(struct mm_struct *mm)
+{
+	/* Invalidate all TLB entries of this process by getting a new ASID */
+	if (mm->context != NO_CONTEXT) {
+		unsigned long flags;
+
+		local_irq_save(flags);
+		mm->context = NO_CONTEXT;
+		if (mm == current->mm)
+			activate_context(mm);
+		local_irq_restore(flags);
+	}
+}
+
+void flush_tlb_all(void)
+{
+	unsigned long flags;
+
+	local_irq_save(flags);
+	sysreg_write(MMUCR, sysreg_read(MMUCR) | SYSREG_BIT(MMUCR_I));
+	local_irq_restore(flags);
+}
+
+#ifdef CONFIG_PROC_FS
+
+#include <linux/seq_file.h>
+#include <linux/proc_fs.h>
+#include <linux/init.h>
+
+static void *tlb_start(struct seq_file *tlb, loff_t *pos)
+{
+	static unsigned long tlb_index;
+
+	if (*pos >= 32)
+		return NULL;
+
+	tlb_index = 0;
+	return &tlb_index;
+}
+
+static void *tlb_next(struct seq_file *tlb, void *v, loff_t *pos)
+{
+	unsigned long *index = v;
+
+	if (*index >= 31)
+		return NULL;
+
+	++*pos;
+	++*index;
+	return index;
+}
+
+static void tlb_stop(struct seq_file *tlb, void *v)
+{
+
+}
+
+static int tlb_show(struct seq_file *tlb, void *v)
+{
+	unsigned int tlbehi, tlbehi_save, tlbelo, mmucr, mmucr_save, flags;
+	unsigned long *index = v;
+
+	if (*index == 0)
+		seq_puts(tlb, "ID  V G ASID VPN   PFN   AP SZ C B W D\n");
+
+	BUG_ON(*index >= 32);
+
+	local_irq_save(flags);
+	mmucr_save = sysreg_read(MMUCR);
+	tlbehi_save = sysreg_read(TLBEHI);
+	mmucr = mmucr_save & 0x13;
+	mmucr |= *index << 14;
+	sysreg_write(MMUCR, mmucr);
+
+	asm volatile("tlbr" : : : "memory");
+	cpu_sync_pipeline();
+
+	tlbehi = sysreg_read(TLBEHI);
+	tlbelo = sysreg_read(TLBELO);
+
+	sysreg_write(MMUCR, mmucr_save);
+	sysreg_write(TLBEHI, tlbehi_save);
+	cpu_sync_pipeline();
+	local_irq_restore(flags);
+
+	seq_printf(tlb, "%2lu: %c %c %02x   %05x %05x %o  %o  %c %c %c %c\n",
+	       *index,
+	       (tlbehi & 0x200)?'1':'0',
+	       (tlbelo & 0x100)?'1':'0',
+	       (tlbehi & 0xff),
+	       (tlbehi >> 12), (tlbelo >> 12),
+	       (tlbelo >> 4) & 7, (tlbelo >> 2) & 3,
+	       (tlbelo & 0x200)?'1':'0',
+	       (tlbelo & 0x080)?'1':'0',
+	       (tlbelo & 0x001)?'1':'0',
+	       (tlbelo & 0x002)?'1':'0');
+
+	return 0;
+}
+
+static struct seq_operations tlb_ops = {
+	.start		= tlb_start,
+	.next		= tlb_next,
+	.stop		= tlb_stop,
+	.show		= tlb_show,
+};
+
+static int tlb_open(struct inode *inode, struct file *file)
+{
+	return seq_open(file, &tlb_ops);
+}
+
+static struct file_operations proc_tlb_operations = {
+	.open		= tlb_open,
+	.read		= seq_read,
+	.llseek		= seq_lseek,
+	.release	= seq_release,
+};
+
+static int __init proctlb_init(void)
+{
+	struct proc_dir_entry *entry;
+
+	entry = create_proc_entry("tlb", 0, NULL);
+	if (entry)
+		entry->proc_fops = &proc_tlb_operations;
+	return 0;
+}
+late_initcall(proctlb_init);
+#endif /* CONFIG_PROC_FS */