linux/arch/avr32/kernel/setup.c
Haavard Skinnemoen d8011768e6 [AVR32] Simplify early handling of memory regions
Use struct resource to specify both physical memory regions and
reserved regions and push everything into the same framework,
including kernel code/data and initrd memory. This allows us to get
rid of many special cases in the bootmem initialization and will also
make it easier to implement more robust handling of framebuffer
memory later.

Signed-off-by: Haavard Skinnemoen <hskinnemoen@atmel.com>
2007-04-27 13:44:14 +02:00

520 lines
13 KiB
C

/*
* 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/clk.h>
#include <linux/init.h>
#include <linux/initrd.h>
#include <linux/sched.h>
#include <linux/console.h>
#include <linux/ioport.h>
#include <linux/bootmem.h>
#include <linux/fs.h>
#include <linux/module.h>
#include <linux/pfn.h>
#include <linux/root_dev.h>
#include <linux/cpu.h>
#include <linux/kernel.h>
#include <asm/sections.h>
#include <asm/processor.h>
#include <asm/pgtable.h>
#include <asm/setup.h>
#include <asm/sysreg.h>
#include <asm/arch/board.h>
#include <asm/arch/init.h>
extern int root_mountflags;
/*
* Initialize loops_per_jiffy as 5000000 (500MIPS).
* Better make it too large than too small...
*/
struct avr32_cpuinfo boot_cpu_data = {
.loops_per_jiffy = 5000000
};
EXPORT_SYMBOL(boot_cpu_data);
static char __initdata command_line[COMMAND_LINE_SIZE];
/*
* Standard memory resources
*/
static struct resource __initdata kernel_data = {
.name = "Kernel data",
.start = 0,
.end = 0,
.flags = IORESOURCE_MEM,
};
static struct resource __initdata kernel_code = {
.name = "Kernel code",
.start = 0,
.end = 0,
.flags = IORESOURCE_MEM,
.sibling = &kernel_data,
};
/*
* Available system RAM and reserved regions as singly linked
* lists. These lists are traversed using the sibling pointer in
* struct resource and are kept sorted at all times.
*/
static struct resource *__initdata system_ram;
static struct resource *__initdata reserved = &kernel_code;
/*
* We need to allocate these before the bootmem allocator is up and
* running, so we need this "cache". 32 entries are probably enough
* for all but the most insanely complex systems.
*/
static struct resource __initdata res_cache[32];
static unsigned int __initdata res_cache_next_free;
static void __init resource_init(void)
{
struct resource *mem, *res;
struct resource *new;
kernel_code.start = __pa(init_mm.start_code);
for (mem = system_ram; mem; mem = mem->sibling) {
new = alloc_bootmem_low(sizeof(struct resource));
memcpy(new, mem, sizeof(struct resource));
new->sibling = NULL;
if (request_resource(&iomem_resource, new))
printk(KERN_WARNING "Bad RAM resource %08x-%08x\n",
mem->start, mem->end);
}
for (res = reserved; res; res = res->sibling) {
new = alloc_bootmem_low(sizeof(struct resource));
memcpy(new, res, sizeof(struct resource));
new->sibling = NULL;
if (insert_resource(&iomem_resource, new))
printk(KERN_WARNING
"Bad reserved resource %s (%08x-%08x)\n",
res->name, res->start, res->end);
}
}
static void __init
add_physical_memory(resource_size_t start, resource_size_t end)
{
struct resource *new, *next, **pprev;
for (pprev = &system_ram, next = system_ram; next;
pprev = &next->sibling, next = next->sibling) {
if (end < next->start)
break;
if (start <= next->end) {
printk(KERN_WARNING
"Warning: Physical memory map is broken\n");
printk(KERN_WARNING
"Warning: %08x-%08x overlaps %08x-%08x\n",
start, end, next->start, next->end);
return;
}
}
if (res_cache_next_free >= ARRAY_SIZE(res_cache)) {
printk(KERN_WARNING
"Warning: Failed to add physical memory %08x-%08x\n",
start, end);
return;
}
new = &res_cache[res_cache_next_free++];
new->start = start;
new->end = end;
new->name = "System RAM";
new->flags = IORESOURCE_MEM;
*pprev = new;
}
static int __init
add_reserved_region(resource_size_t start, resource_size_t end,
const char *name)
{
struct resource *new, *next, **pprev;
if (end < start)
return -EINVAL;
if (res_cache_next_free >= ARRAY_SIZE(res_cache))
return -ENOMEM;
for (pprev = &reserved, next = reserved; next;
pprev = &next->sibling, next = next->sibling) {
if (end < next->start)
break;
if (start <= next->end)
return -EBUSY;
}
new = &res_cache[res_cache_next_free++];
new->start = start;
new->end = end;
new->name = name;
new->flags = IORESOURCE_MEM;
*pprev = new;
return 0;
}
static unsigned long __init
find_free_region(const struct resource *mem, resource_size_t size,
resource_size_t align)
{
struct resource *res;
unsigned long target;
target = ALIGN(mem->start, align);
for (res = reserved; res; res = res->sibling) {
if ((target + size) <= res->start)
break;
if (target <= res->end)
target = ALIGN(res->end + 1, align);
}
if ((target + size) > (mem->end + 1))
return mem->end + 1;
return target;
}
/*
* Early framebuffer allocation. Works as follows:
* - If fbmem_size is zero, nothing will be allocated or reserved.
* - If fbmem_start is zero when setup_bootmem() is called,
* fbmem_size bytes will be allocated from the bootmem allocator.
* - If fbmem_start is nonzero, an area of size fbmem_size will be
* reserved at the physical address fbmem_start if necessary. If
* the area isn't in a memory region known to the kernel, it will
* be left alone.
*
* Board-specific code may use these variables to set up platform data
* for the framebuffer driver if fbmem_size is nonzero.
*/
static unsigned long __initdata fbmem_start;
static unsigned long __initdata fbmem_size;
/*
* "fbmem=xxx[kKmM]" allocates the specified amount of boot memory for
* use as framebuffer.
*
* "fbmem=xxx[kKmM]@yyy[kKmM]" defines a memory region of size xxx and
* starting at yyy to be reserved for use as framebuffer.
*
* The kernel won't verify that the memory region starting at yyy
* actually contains usable RAM.
*/
static int __init early_parse_fbmem(char *p)
{
fbmem_size = memparse(p, &p);
if (*p == '@')
fbmem_start = memparse(p, &p);
return 0;
}
early_param("fbmem", early_parse_fbmem);
static int __init parse_tag_core(struct tag *tag)
{
if (tag->hdr.size > 2) {
if ((tag->u.core.flags & 1) == 0)
root_mountflags &= ~MS_RDONLY;
ROOT_DEV = new_decode_dev(tag->u.core.rootdev);
}
return 0;
}
__tagtable(ATAG_CORE, parse_tag_core);
static int __init parse_tag_mem(struct tag *tag)
{
unsigned long start, end;
/*
* Ignore zero-sized entries. If we're running standalone, the
* SDRAM code may emit such entries if something goes
* wrong...
*/
if (tag->u.mem_range.size == 0)
return 0;
start = tag->u.mem_range.addr;
end = tag->u.mem_range.addr + tag->u.mem_range.size - 1;
add_physical_memory(start, end);
return 0;
}
__tagtable(ATAG_MEM, parse_tag_mem);
static int __init parse_tag_rdimg(struct tag *tag)
{
#ifdef CONFIG_INITRD
struct tag_mem_range *mem = &tag->u.mem_range;
int ret;
if (initrd_start) {
printk(KERN_WARNING
"Warning: Only the first initrd image will be used\n");
return 0;
}
ret = add_reserved_region(mem->start, mem->start + mem->size - 1,
"initrd");
if (ret) {
printk(KERN_WARNING
"Warning: Failed to reserve initrd memory\n");
return ret;
}
initrd_start = (unsigned long)__va(mem->addr);
initrd_end = initrd_start + mem->size;
#else
printk(KERN_WARNING "RAM disk image present, but "
"no initrd support in kernel, ignoring\n");
#endif
return 0;
}
__tagtable(ATAG_RDIMG, parse_tag_rdimg);
static int __init parse_tag_rsvd_mem(struct tag *tag)
{
struct tag_mem_range *mem = &tag->u.mem_range;
return add_reserved_region(mem->addr, mem->addr + mem->size - 1,
"Reserved");
}
__tagtable(ATAG_RSVD_MEM, parse_tag_rsvd_mem);
static int __init parse_tag_cmdline(struct tag *tag)
{
strlcpy(boot_command_line, tag->u.cmdline.cmdline, COMMAND_LINE_SIZE);
return 0;
}
__tagtable(ATAG_CMDLINE, parse_tag_cmdline);
static int __init parse_tag_clock(struct tag *tag)
{
/*
* We'll figure out the clocks by peeking at the system
* manager regs directly.
*/
return 0;
}
__tagtable(ATAG_CLOCK, parse_tag_clock);
/*
* Scan the tag table for this tag, and call its parse function. The
* tag table is built by the linker from all the __tagtable
* declarations.
*/
static int __init parse_tag(struct tag *tag)
{
extern struct tagtable __tagtable_begin, __tagtable_end;
struct tagtable *t;
for (t = &__tagtable_begin; t < &__tagtable_end; t++)
if (tag->hdr.tag == t->tag) {
t->parse(tag);
break;
}
return t < &__tagtable_end;
}
/*
* Parse all tags in the list we got from the boot loader
*/
static void __init parse_tags(struct tag *t)
{
for (; t->hdr.tag != ATAG_NONE; t = tag_next(t))
if (!parse_tag(t))
printk(KERN_WARNING
"Ignoring unrecognised tag 0x%08x\n",
t->hdr.tag);
}
/*
* Find a free memory region large enough for storing the
* bootmem bitmap.
*/
static unsigned long __init
find_bootmap_pfn(const struct resource *mem)
{
unsigned long bootmap_pages, bootmap_len;
unsigned long node_pages = PFN_UP(mem->end - mem->start + 1);
unsigned long bootmap_start;
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 that we don't collide with any reserved
* regions, which includes the kernel image and any RAMDISK
* images.
*/
bootmap_start = find_free_region(mem, bootmap_len, PAGE_SIZE);
return bootmap_start >> PAGE_SHIFT;
}
#define MAX_LOWMEM HIGHMEM_START
#define MAX_LOWMEM_PFN PFN_DOWN(MAX_LOWMEM)
static void __init setup_bootmem(void)
{
unsigned bootmap_size;
unsigned long first_pfn, bootmap_pfn, pages;
unsigned long max_pfn, max_low_pfn;
unsigned node = 0;
struct resource *res;
printk(KERN_INFO "Physical memory:\n");
for (res = system_ram; res; res = res->sibling)
printk(" %08x-%08x\n", res->start, res->end);
printk(KERN_INFO "Reserved memory:\n");
for (res = reserved; res; res = res->sibling)
printk(" %08x-%08x: %s\n",
res->start, res->end, res->name);
nodes_clear(node_online_map);
if (system_ram->sibling)
printk(KERN_WARNING "Only using first memory bank\n");
for (res = system_ram; res; res = NULL) {
first_pfn = PFN_UP(res->start);
max_low_pfn = max_pfn = PFN_DOWN(res->end + 1);
bootmap_pfn = find_bootmap_pfn(res);
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);
/*
* 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 bootmem bitmap... */
reserve_bootmem_node(NODE_DATA(node),
PFN_PHYS(bootmap_pfn),
bootmap_size);
/* ...and any other reserved regions. */
for (res = reserved; res; res = res->sibling) {
if (res->start > PFN_PHYS(max_pfn))
break;
/*
* resource_init will complain about partial
* overlaps, so we'll just ignore such
* resources for now.
*/
if (res->start >= PFN_PHYS(first_pfn)
&& res->end < PFN_PHYS(max_pfn))
reserve_bootmem_node(
NODE_DATA(node), res->start,
res->end - res->start + 1);
}
node_set_online(node);
}
}
void __init setup_arch (char **cmdline_p)
{
struct clk *cpu_clk;
init_mm.start_code = (unsigned long)_text;
init_mm.end_code = (unsigned long)_etext;
init_mm.end_data = (unsigned long)_edata;
init_mm.brk = (unsigned long)_end;
/*
* Include .init section to make allocations easier. It will
* be removed before the resource is actually requested.
*/
kernel_code.start = __pa(__init_begin);
kernel_code.end = __pa(init_mm.end_code - 1);
kernel_data.start = __pa(init_mm.end_code);
kernel_data.end = __pa(init_mm.brk - 1);
parse_tags(bootloader_tags);
setup_processor();
setup_platform();
setup_board();
cpu_clk = clk_get(NULL, "cpu");
if (IS_ERR(cpu_clk)) {
printk(KERN_WARNING "Warning: Unable to get CPU clock\n");
} else {
unsigned long cpu_hz = clk_get_rate(cpu_clk);
/*
* Well, duh, but it's probably a good idea to
* increment the use count.
*/
clk_enable(cpu_clk);
boot_cpu_data.clk = cpu_clk;
boot_cpu_data.loops_per_jiffy = cpu_hz * 4;
printk("CPU: Running at %lu.%03lu MHz\n",
((cpu_hz + 500) / 1000) / 1000,
((cpu_hz + 500) / 1000) % 1000);
}
strlcpy(command_line, boot_command_line, COMMAND_LINE_SIZE);
*cmdline_p = command_line;
parse_early_param();
setup_bootmem();
board_setup_fbmem(fbmem_start, fbmem_size);
#ifdef CONFIG_VT
conswitchp = &dummy_con;
#endif
paging_init();
resource_init();
}