blackfin architecture

This adds support for the Analog Devices Blackfin processor architecture, and
currently supports the BF533, BF532, BF531, BF537, BF536, BF534, and BF561
(Dual Core) devices, with a variety of development platforms including those
avaliable from Analog Devices (BF533-EZKit, BF533-STAMP, BF537-STAMP,
BF561-EZKIT), and Bluetechnix!  Tinyboards.

The Blackfin architecture was jointly developed by Intel and Analog Devices
Inc.  (ADI) as the Micro Signal Architecture (MSA) core and introduced it in
December of 2000.  Since then ADI has put this core into its Blackfin
processor family of devices.  The Blackfin core has the advantages of a clean,
orthogonal,RISC-like microprocessor instruction set.  It combines a dual-MAC
(Multiply/Accumulate), state-of-the-art signal processing engine and
single-instruction, multiple-data (SIMD) multimedia capabilities into a single
instruction-set architecture.

The Blackfin architecture, including the instruction set, is described by the
ADSP-BF53x/BF56x Blackfin Processor Programming Reference
http://blackfin.uclinux.org/gf/download/frsrelease/29/2549/Blackfin_PRM.pdf

The Blackfin processor is already supported by major releases of gcc, and
there are binary and source rpms/tarballs for many architectures at:
http://blackfin.uclinux.org/gf/project/toolchain/frs There is complete
documentation, including "getting started" guides available at:
http://docs.blackfin.uclinux.org/ which provides links to the sources and
patches you will need in order to set up a cross-compiling environment for
bfin-linux-uclibc

This patch, as well as the other patches (toolchain, distribution,
uClibc) are actively supported by Analog Devices Inc, at:
http://blackfin.uclinux.org/

We have tested this on LTP, and our test plan (including pass/fails) can
be found at:
http://docs.blackfin.uclinux.org/doku.php?id=testing_the_linux_kernel

[m.kozlowski@tuxland.pl: balance parenthesis in blackfin header files]
Signed-off-by: Bryan Wu <bryan.wu@analog.com>
Signed-off-by: Mariusz Kozlowski <m.kozlowski@tuxland.pl>
Signed-off-by: Aubrey Li <aubrey.li@analog.com>
Signed-off-by: Jie Zhang <jie.zhang@analog.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 208 insertions, 0 deletions

diff --git a/arch/blackfin/mm/init.c b/arch/blackfin/mm/init.c
new file mode 100644
index 0000000..73f72ab
--- /dev/null
+++ b/arch/blackfin/mm/init.c
@@ -0,0 +1,208 @@
+/*
+ * File:         arch/blackfin/mm/init.c
+ * Based on:
+ * Author:
+ *
+ * Created:
+ * Description:
+ *
+ * Modified:
+ *               Copyright 2004-2006 Analog Devices Inc.
+ *
+ * Bugs:         Enter bugs at http://blackfin.uclinux.org/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see the file COPYING, or write
+ * to the Free Software Foundation, Inc.,
+ * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
+ */
+
+#include <linux/swap.h>
+#include <linux/bootmem.h>
+#include <asm/bfin-global.h>
+#include <asm/uaccess.h>
+#include <asm/l1layout.h>
+#include "blackfin_sram.h"
+
+/*
+ * BAD_PAGE is the page that is used for page faults when linux
+ * is out-of-memory. Older versions of linux just did a
+ * do_exit(), but using this instead means there is less risk
+ * for a process dying in kernel mode, possibly leaving a inode
+ * unused etc..
+ *
+ * BAD_PAGETABLE is the accompanying page-table: it is initialized
+ * to point to BAD_PAGE entries.
+ *
+ * ZERO_PAGE is a special page that is used for zero-initialized
+ * data and COW.
+ */
+static unsigned long empty_bad_page_table;
+
+static unsigned long empty_bad_page;
+
+unsigned long empty_zero_page;
+
+void show_mem(void)
+{
+	unsigned long i;
+	int free = 0, total = 0, reserved = 0, shared = 0;
+
+	int cached = 0;
+	printk(KERN_INFO "Mem-info:\n");
+	show_free_areas();
+	i = max_mapnr;
+	while (i-- > 0) {
+		total++;
+		if (PageReserved(mem_map + i))
+			reserved++;
+		else if (PageSwapCache(mem_map + i))
+			cached++;
+		else if (!page_count(mem_map + i))
+			free++;
+		else
+			shared += page_count(mem_map + i) - 1;
+	}
+	printk(KERN_INFO "%d pages of RAM\n", total);
+	printk(KERN_INFO "%d free pages\n", free);
+	printk(KERN_INFO "%d reserved pages\n", reserved);
+	printk(KERN_INFO "%d pages shared\n", shared);
+	printk(KERN_INFO "%d pages swap cached\n", cached);
+}
+
+/*
+ * paging_init() continues the virtual memory environment setup which
+ * was begun by the code in arch/head.S.
+ * The parameters are pointers to where to stick the starting and ending
+ * addresses  of available kernel virtual memory.
+ */
+void paging_init(void)
+{
+	/*
+	 * make sure start_mem is page aligned,  otherwise bootmem and
+	 * page_alloc get different views og the world
+	 */
+	unsigned long end_mem = memory_end & PAGE_MASK;
+
+	pr_debug("start_mem is %#lx   virtual_end is %#lx\n", PAGE_ALIGN(memory_start), end_mem);
+
+	/*
+	 * initialize the bad page table and bad page to point
+	 * to a couple of allocated pages
+	 */
+	empty_bad_page_table = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
+	empty_bad_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
+	empty_zero_page = (unsigned long)alloc_bootmem_pages(PAGE_SIZE);
+	memset((void *)empty_zero_page, 0, PAGE_SIZE);
+
+	/*
+	 * Set up SFC/DFC registers (user data space)
+	 */
+	set_fs(KERNEL_DS);
+
+	pr_debug("free_area_init -> start_mem is %#lx   virtual_end is %#lx\n",
+	        PAGE_ALIGN(memory_start), end_mem);
+
+	{
+		unsigned long zones_size[MAX_NR_ZONES] = { 0, };
+
+		zones_size[ZONE_NORMAL] = (end_mem - PAGE_OFFSET) >> PAGE_SHIFT;
+#ifdef CONFIG_HIGHMEM
+		zones_size[ZONE_HIGHMEM] = 0;
+#endif
+		free_area_init(zones_size);
+	}
+}
+
+void mem_init(void)
+{
+	unsigned int codek = 0, datak = 0, initk = 0;
+	unsigned long tmp;
+	unsigned int len = _ramend - _rambase;
+	unsigned long start_mem = memory_start;
+	unsigned long end_mem = memory_end;
+
+	end_mem &= PAGE_MASK;
+	high_memory = (void *)end_mem;
+
+	start_mem = PAGE_ALIGN(start_mem);
+	max_mapnr = num_physpages = MAP_NR(high_memory);
+	printk(KERN_INFO "Physical pages: %lx\n", num_physpages);
+
+	/* This will put all memory onto the freelists. */
+	totalram_pages = free_all_bootmem();
+
+	codek = (_etext - _stext) >> 10;
+	datak = (__bss_stop - __bss_start) >> 10;
+	initk = (__init_end - __init_begin) >> 10;
+
+	tmp = nr_free_pages() << PAGE_SHIFT;
+	printk(KERN_INFO
+	     "Memory available: %luk/%uk RAM, (%uk init code, %uk kernel code, %uk data, %uk dma)\n",
+	     tmp >> 10, len >> 10, initk, codek, datak, DMA_UNCACHED_REGION >> 10);
+
+	/* Initialize the blackfin L1 Memory. */
+	l1sram_init();
+	l1_data_sram_init();
+	l1_inst_sram_init();
+
+	/* Allocate this once; never free it.  We assume this gives us a
+	   pointer to the start of L1 scratchpad memory; panic if it
+	   doesn't.  */
+	tmp = (unsigned long)l1sram_alloc(sizeof(struct l1_scratch_task_info));
+	if (tmp != (unsigned long)L1_SCRATCH_TASK_INFO) {
+		printk(KERN_EMERG "mem_init(): Did not get the right address from l1sram_alloc: %08lx != %08lx\n",
+			tmp, (unsigned long)L1_SCRATCH_TASK_INFO);
+		panic("No L1, time to give up\n");
+	}
+}
+
+#ifdef CONFIG_BLK_DEV_INITRD
+void free_initrd_mem(unsigned long start, unsigned long end)
+{
+	int pages = 0;
+	for (; start < end; start += PAGE_SIZE) {
+		ClearPageReserved(virt_to_page(start));
+		init_page_count(virt_to_page(start));
+		free_page(start);
+		totalram_pages++;
+		pages++;
+	}
+	printk(KERN_NOTICE "Freeing initrd memory: %dk freed\n", pages);
+}
+#endif
+
+void free_initmem(void)
+{
+#ifdef CONFIG_RAMKERNEL
+	unsigned long addr;
+/*
+ *	the following code should be cool even if these sections
+ *	are not page aligned.
+ */
+	addr = PAGE_ALIGN((unsigned long)(__init_begin));
+	/* next to check that the page we free is not a partial page */
+	for (; addr + PAGE_SIZE < (unsigned long)(__init_end);
+	     addr += PAGE_SIZE) {
+		ClearPageReserved(virt_to_page(addr));
+		init_page_count(virt_to_page(addr));
+		free_page(addr);
+		totalram_pages++;
+	}
+	printk(KERN_NOTICE
+	       "Freeing unused kernel memory: %ldk freed (0x%x - 0x%x)\n",
+	       (addr - PAGE_ALIGN((long)__init_begin)) >> 10,
+	       (int)(PAGE_ALIGN((unsigned long)(__init_begin))),
+	       (int)(addr - PAGE_SIZE));
+#endif
+}