[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, 480 insertions, 0 deletions

diff --git a/arch/avr32/mm/init.c b/arch/avr32/mm/init.c
new file mode 100644
index 00000000000..3e6c4103980
--- /dev/null
+++ b/arch/avr32/mm/init.c
@@ -0,0 +1,480 @@
+/*
+ * 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/kernel.h>
+#include <linux/mm.h>
+#include <linux/swap.h>
+#include <linux/init.h>
+#include <linux/initrd.h>
+#include <linux/mmzone.h>
+#include <linux/bootmem.h>
+#include <linux/pagemap.h>
+#include <linux/pfn.h>
+#include <linux/nodemask.h>
+
+#include <asm/page.h>
+#include <asm/mmu_context.h>
+#include <asm/tlb.h>
+#include <asm/io.h>
+#include <asm/dma.h>
+#include <asm/setup.h>
+#include <asm/sections.h>
+
+DEFINE_PER_CPU(struct mmu_gather, mmu_gathers);
+
+pgd_t swapper_pg_dir[PTRS_PER_PGD];
+
+struct page *empty_zero_page;
+
+/*
+ * Cache of MMU context last used.
+ */
+unsigned long mmu_context_cache = NO_CONTEXT;
+
+#define START_PFN	(NODE_DATA(0)->bdata->node_boot_start >> PAGE_SHIFT)
+#define MAX_LOW_PFN	(NODE_DATA(0)->bdata->node_low_pfn)
+
+void show_mem(void)
+{
+	int total = 0, reserved = 0, cached = 0;
+	int slab = 0, free = 0, shared = 0;
+	pg_data_t *pgdat;
+
+	printk("Mem-info:\n");
+	show_free_areas();
+
+	for_each_online_pgdat(pgdat) {
+		struct page *page, *end;
+
+		page = pgdat->node_mem_map;
+		end = page + pgdat->node_spanned_pages;
+
+		do {
+			total++;
+			if (PageReserved(page))
+				reserved++;
+			else if (PageSwapCache(page))
+				cached++;
+			else if (PageSlab(page))
+				slab++;
+			else if (!page_count(page))
+				free++;
+			else
+				shared += page_count(page) - 1;
+			page++;
+		} while (page < end);
+	}
+
+	printk ("%d pages of RAM\n", total);
+	printk ("%d free pages\n", free);
+	printk ("%d reserved pages\n", reserved);
+	printk ("%d slab pages\n", slab);
+	printk ("%d pages shared\n", shared);
+	printk ("%d pages swap cached\n", cached);
+}
+
+static void __init print_memory_map(const char *what,
+				    struct tag_mem_range *mem)
+{
+	printk ("%s:\n", what);
+	for (; mem; mem = mem->next) {
+		printk ("  %08lx - %08lx\n",
+			(unsigned long)mem->addr,
+			(unsigned long)(mem->addr + mem->size));
+	}
+}
+
+#define MAX_LOWMEM	HIGHMEM_START
+#define MAX_LOWMEM_PFN	PFN_DOWN(MAX_LOWMEM)
+
+/*
+ * Sort a list of memory regions in-place by ascending address.
+ *
+ * We're using bubble sort because we only have singly linked lists
+ * with few elements.
+ */
+static void __init sort_mem_list(struct tag_mem_range **pmem)
+{
+	int done;
+	struct tag_mem_range **a, **b;
+
+	if (!*pmem)
+		return;
+
+	do {
+		done = 1;
+		a = pmem, b = &(*pmem)->next;
+		while (*b) {
+			if ((*a)->addr > (*b)->addr) {
+				struct tag_mem_range *tmp;
+				tmp = (*b)->next;
+				(*b)->next = *a;
+				*a = *b;
+				*b = tmp;
+				done = 0;
+			}
+			a = &(*a)->next;
+			b = &(*a)->next;
+		}
+	} while (!done);
+}
+
+/*
+ * Find a free memory region large enough for storing the
+ * bootmem bitmap.
+ */
+static unsigned long __init
+find_bootmap_pfn(const struct tag_mem_range *mem)
+{
+	unsigned long bootmap_pages, bootmap_len;
+	unsigned long node_pages = PFN_UP(mem->size);
+	unsigned long bootmap_addr = mem->addr;
+	struct tag_mem_range *reserved = mem_reserved;
+	struct tag_mem_range *ramdisk = mem_ramdisk;
+	unsigned long kern_start = virt_to_phys(_stext);
+	unsigned long kern_end = virt_to_phys(_end);
+
+	bootmap_pages = bootmem_bootmap_pages(node_pages);
+	bootmap_len = bootmap_pages << PAGE_SHIFT;
+
+	/*
+	 * Find a large enough region without reserved pages for
+	 * storing the bootmem bitmap. We can take advantage of the
+	 * fact that all lists have been sorted.
+	 *
+	 * We have to check explicitly reserved regions as well as the
+	 * kernel image and any RAMDISK images...
+	 *
+	 * Oh, and we have to make sure we don't overwrite the taglist
+	 * since we're going to use it until the bootmem allocator is
+	 * fully up and running.
+	 */
+	while (1) {
+		if ((bootmap_addr < kern_end) &&
+		    ((bootmap_addr + bootmap_len) > kern_start))
+			bootmap_addr = kern_end;
+
+		while (reserved &&
+		       (bootmap_addr >= (reserved->addr + reserved->size)))
+			reserved = reserved->next;
+
+		if (reserved &&
+		    ((bootmap_addr + bootmap_len) >= reserved->addr)) {
+			bootmap_addr = reserved->addr + reserved->size;
+			continue;
+		}
+
+		while (ramdisk &&
+		       (bootmap_addr >= (ramdisk->addr + ramdisk->size)))
+			ramdisk = ramdisk->next;
+
+		if (!ramdisk ||
+		    ((bootmap_addr + bootmap_len) < ramdisk->addr))
+			break;
+
+		bootmap_addr = ramdisk->addr + ramdisk->size;
+	}
+
+	if ((PFN_UP(bootmap_addr) + bootmap_len) >= (mem->addr + mem->size))
+		return ~0UL;
+
+	return PFN_UP(bootmap_addr);
+}
+
+void __init setup_bootmem(void)
+{
+	unsigned bootmap_size;
+	unsigned long first_pfn, bootmap_pfn, pages;
+	unsigned long max_pfn, max_low_pfn;
+	unsigned long kern_start = virt_to_phys(_stext);
+	unsigned long kern_end = virt_to_phys(_end);
+	unsigned node = 0;
+	struct tag_mem_range *bank, *res;
+
+	sort_mem_list(&mem_phys);
+	sort_mem_list(&mem_reserved);
+
+	print_memory_map("Physical memory", mem_phys);
+	print_memory_map("Reserved memory", mem_reserved);
+
+	nodes_clear(node_online_map);
+
+	if (mem_ramdisk) {
+#ifdef CONFIG_BLK_DEV_INITRD
+		initrd_start = __va(mem_ramdisk->addr);
+		initrd_end = initrd_start + mem_ramdisk->size;
+
+		print_memory_map("RAMDISK images", mem_ramdisk);
+		if (mem_ramdisk->next)
+			printk(KERN_WARNING
+			       "Warning: Only the first RAMDISK image "
+			       "will be used\n");
+		sort_mem_list(&mem_ramdisk);
+#else
+		printk(KERN_WARNING "RAM disk image present, but "
+		       "no initrd support in kernel!\n");
+#endif
+	}
+
+	if (mem_phys->next)
+		printk(KERN_WARNING "Only using first memory bank\n");
+
+	for (bank = mem_phys; bank; bank = NULL) {
+		first_pfn = PFN_UP(bank->addr);
+		max_low_pfn = max_pfn = PFN_DOWN(bank->addr + bank->size);
+		bootmap_pfn = find_bootmap_pfn(bank);
+		if (bootmap_pfn > max_pfn)
+			panic("No space for bootmem bitmap!\n");
+
+		if (max_low_pfn > MAX_LOWMEM_PFN) {
+			max_low_pfn = MAX_LOWMEM_PFN;
+#ifndef CONFIG_HIGHMEM
+			/*
+			 * Lowmem is memory that can be addressed
+			 * directly through P1/P2
+			 */
+			printk(KERN_WARNING
+			       "Node %u: Only %ld MiB of memory will be used.\n",
+			       node, MAX_LOWMEM >> 20);
+			printk(KERN_WARNING "Use a HIGHMEM enabled kernel.\n");
+#else
+#error HIGHMEM is not supported by AVR32 yet
+#endif
+		}
+
+		/* Initialize the boot-time allocator with low memory only. */
+		bootmap_size = init_bootmem_node(NODE_DATA(node), bootmap_pfn,
+						 first_pfn, max_low_pfn);
+
+		printk("Node %u: bdata = %p, bdata->node_bootmem_map = %p\n",
+		       node, NODE_DATA(node)->bdata,
+		       NODE_DATA(node)->bdata->node_bootmem_map);
+
+		/*
+		 * Register fully available RAM pages with the bootmem
+		 * allocator.
+		 */
+		pages = max_low_pfn - first_pfn;
+		free_bootmem_node (NODE_DATA(node), PFN_PHYS(first_pfn),
+				   PFN_PHYS(pages));
+
+		/*
+		 * Reserve space for the kernel image (if present in
+		 * this node)...
+		 */
+		if ((kern_start >= PFN_PHYS(first_pfn)) &&
+		    (kern_start < PFN_PHYS(max_pfn))) {
+			printk("Node %u: Kernel image %08lx - %08lx\n",
+			       node, kern_start, kern_end);
+			reserve_bootmem_node(NODE_DATA(node), kern_start,
+					     kern_end - kern_start);
+		}
+
+		/* ...the bootmem bitmap... */
+		reserve_bootmem_node(NODE_DATA(node),
+				     PFN_PHYS(bootmap_pfn),
+				     bootmap_size);
+
+		/* ...any RAMDISK images... */
+		for (res = mem_ramdisk; res; res = res->next) {
+			if (res->addr > PFN_PHYS(max_pfn))
+				break;
+
+			if (res->addr >= PFN_PHYS(first_pfn)) {
+				printk("Node %u: RAMDISK %08lx - %08lx\n",
+				       node,
+				       (unsigned long)res->addr,
+				       (unsigned long)(res->addr + res->size));
+				reserve_bootmem_node(NODE_DATA(node),
+						     res->addr, res->size);
+			}
+		}
+
+		/* ...and any other reserved regions. */
+		for (res = mem_reserved; res; res = res->next) {
+			if (res->addr > PFN_PHYS(max_pfn))
+				break;
+
+			if (res->addr >= PFN_PHYS(first_pfn)) {
+				printk("Node %u: Reserved %08lx - %08lx\n",
+				       node,
+				       (unsigned long)res->addr,
+				       (unsigned long)(res->addr + res->size));
+				reserve_bootmem_node(NODE_DATA(node),
+						     res->addr, res->size);
+			}
+		}
+
+		node_set_online(node);
+	}
+}
+
+/*
+ * paging_init() sets up the page tables
+ *
+ * This routine also unmaps the page at virtual kernel address 0, so
+ * that we can trap those pesky NULL-reference errors in the kernel.
+ */
+void __init paging_init(void)
+{
+	extern unsigned long _evba;
+	void *zero_page;
+	int nid;
+
+	/*
+	 * Make sure we can handle exceptions before enabling
+	 * paging. Not that we should ever _get_ any exceptions this
+	 * early, but you never know...
+	 */
+	printk("Exception vectors start at %p\n", &_evba);
+	sysreg_write(EVBA, (unsigned long)&_evba);
+
+	/*
+	 * Since we are ready to handle exceptions now, we should let
+	 * the CPU generate them...
+	 */
+	__asm__ __volatile__ ("csrf %0" : : "i"(SR_EM_BIT));
+
+	/*
+	 * Allocate the zero page. The allocator will panic if it
+	 * can't satisfy the request, so no need to check.
+	 */
+	zero_page = alloc_bootmem_low_pages_node(NODE_DATA(0),
+						 PAGE_SIZE);
+
+	{
+		pgd_t *pg_dir;
+		int i;
+
+		pg_dir = swapper_pg_dir;
+		sysreg_write(PTBR, (unsigned long)pg_dir);
+
+		for (i = 0; i < PTRS_PER_PGD; i++)
+			pgd_val(pg_dir[i]) = 0;
+
+		enable_mmu();
+		printk ("CPU: Paging enabled\n");
+	}
+
+	for_each_online_node(nid) {
+		pg_data_t *pgdat = NODE_DATA(nid);
+		unsigned long zones_size[MAX_NR_ZONES];
+		unsigned long low, start_pfn;
+
+		start_pfn = pgdat->bdata->node_boot_start;
+		start_pfn >>= PAGE_SHIFT;
+		low = pgdat->bdata->node_low_pfn;
+
+		memset(zones_size, 0, sizeof(zones_size));
+		zones_size[ZONE_NORMAL] = low - start_pfn;
+
+		printk("Node %u: start_pfn = 0x%lx, low = 0x%lx\n",
+		       nid, start_pfn, low);
+
+		free_area_init_node(nid, pgdat, zones_size, start_pfn, NULL);
+
+		printk("Node %u: mem_map starts at %p\n",
+		       pgdat->node_id, pgdat->node_mem_map);
+	}
+
+	mem_map = NODE_DATA(0)->node_mem_map;
+
+	memset(zero_page, 0, PAGE_SIZE);
+	empty_zero_page = virt_to_page(zero_page);
+	flush_dcache_page(empty_zero_page);
+}
+
+void __init mem_init(void)
+{
+	int codesize, reservedpages, datasize, initsize;
+	int nid, i;
+
+	reservedpages = 0;
+	high_memory = NULL;
+
+	/* this will put all low memory onto the freelists */
+	for_each_online_node(nid) {
+		pg_data_t *pgdat = NODE_DATA(nid);
+		unsigned long node_pages = 0;
+		void *node_high_memory;
+
+		num_physpages += pgdat->node_present_pages;
+
+		if (pgdat->node_spanned_pages != 0)
+			node_pages = free_all_bootmem_node(pgdat);
+
+		totalram_pages += node_pages;
+
+		for (i = 0; i < node_pages; i++)
+			if (PageReserved(pgdat->node_mem_map + i))
+				reservedpages++;
+
+		node_high_memory = (void *)((pgdat->node_start_pfn
+					     + pgdat->node_spanned_pages)
+					    << PAGE_SHIFT);
+		if (node_high_memory > high_memory)
+			high_memory = node_high_memory;
+	}
+
+	max_mapnr = MAP_NR(high_memory);
+
+	codesize = (unsigned long)_etext - (unsigned long)_text;
+	datasize = (unsigned long)_edata - (unsigned long)_data;
+	initsize = (unsigned long)__init_end - (unsigned long)__init_begin;
+
+	printk ("Memory: %luk/%luk available (%dk kernel code, "
+		"%dk reserved, %dk data, %dk init)\n",
+		(unsigned long)nr_free_pages() << (PAGE_SHIFT - 10),
+		totalram_pages << (PAGE_SHIFT - 10),
+		codesize >> 10,
+		reservedpages << (PAGE_SHIFT - 10),
+		datasize >> 10,
+		initsize >> 10);
+}
+
+static inline void free_area(unsigned long addr, unsigned long end, char *s)
+{
+	unsigned int size = (end - addr) >> 10;
+
+	for (; addr < end; addr += PAGE_SIZE) {
+		struct page *page = virt_to_page(addr);
+		ClearPageReserved(page);
+		init_page_count(page);
+		free_page(addr);
+		totalram_pages++;
+	}
+
+	if (size && s)
+		printk(KERN_INFO "Freeing %s memory: %dK (%lx - %lx)\n",
+		       s, size, end - (size << 10), end);
+}
+
+void free_initmem(void)
+{
+	free_area((unsigned long)__init_begin, (unsigned long)__init_end,
+		  "init");
+}
+
+#ifdef CONFIG_BLK_DEV_INITRD
+
+static int keep_initrd;
+
+void free_initrd_mem(unsigned long start, unsigned long end)
+{
+	if (!keep_initrd)
+		free_area(start, end, "initrd");
+}
+
+static int __init keepinitrd_setup(char *__unused)
+{
+	keep_initrd = 1;
+	return 1;
+}
+
+__setup("keepinitrd", keepinitrd_setup);
+#endif