linux/arch/microblaze/mm/init.c
Michal Simek 95b0f9ea66 microblaze: Improve TLB calculation for small systems
Systems with small amount of memory need to be handled
differently. Linux can't allocate the whole 32MB with two TLBs
because then there is no MMU protection.

Signed-off-by: Michal Simek <monstr@monstr.eu>
2012-03-23 09:28:18 +01:00

503 lines
13 KiB
C

/*
* Copyright (C) 2007-2008 Michal Simek <monstr@monstr.eu>
* Copyright (C) 2006 Atmark Techno, Inc.
*
* 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/bootmem.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/memblock.h>
#include <linux/mm.h> /* mem_init */
#include <linux/initrd.h>
#include <linux/pagemap.h>
#include <linux/pfn.h>
#include <linux/slab.h>
#include <linux/swap.h>
#include <linux/export.h>
#include <asm/page.h>
#include <asm/mmu_context.h>
#include <asm/pgalloc.h>
#include <asm/sections.h>
#include <asm/tlb.h>
#include <asm/fixmap.h>
/* Use for MMU and noMMU because of PCI generic code */
int mem_init_done;
#ifndef CONFIG_MMU
unsigned int __page_offset;
EXPORT_SYMBOL(__page_offset);
#else
static int init_bootmem_done;
#endif /* CONFIG_MMU */
char *klimit = _end;
/*
* Initialize the bootmem system and give it all the memory we
* have available.
*/
unsigned long memory_start;
EXPORT_SYMBOL(memory_start);
unsigned long memory_size;
EXPORT_SYMBOL(memory_size);
unsigned long lowmem_size;
#ifdef CONFIG_HIGHMEM
pte_t *kmap_pte;
EXPORT_SYMBOL(kmap_pte);
pgprot_t kmap_prot;
EXPORT_SYMBOL(kmap_prot);
static inline pte_t *virt_to_kpte(unsigned long vaddr)
{
return pte_offset_kernel(pmd_offset(pgd_offset_k(vaddr),
vaddr), vaddr);
}
static void __init highmem_init(void)
{
pr_debug("%x\n", (u32)PKMAP_BASE);
map_page(PKMAP_BASE, 0, 0); /* XXX gross */
pkmap_page_table = virt_to_kpte(PKMAP_BASE);
kmap_pte = virt_to_kpte(__fix_to_virt(FIX_KMAP_BEGIN));
kmap_prot = PAGE_KERNEL;
}
static unsigned long highmem_setup(void)
{
unsigned long pfn;
unsigned long reservedpages = 0;
for (pfn = max_low_pfn; pfn < max_pfn; ++pfn) {
struct page *page = pfn_to_page(pfn);
/* FIXME not sure about */
if (memblock_is_reserved(pfn << PAGE_SHIFT))
continue;
ClearPageReserved(page);
init_page_count(page);
__free_page(page);
totalhigh_pages++;
reservedpages++;
}
totalram_pages += totalhigh_pages;
printk(KERN_INFO "High memory: %luk\n",
totalhigh_pages << (PAGE_SHIFT-10));
return reservedpages;
}
#endif /* CONFIG_HIGHMEM */
/*
* paging_init() sets up the page tables - in fact we've already done this.
*/
static void __init paging_init(void)
{
unsigned long zones_size[MAX_NR_ZONES];
#ifdef CONFIG_MMU
int idx;
/* Setup fixmaps */
for (idx = 0; idx < __end_of_fixed_addresses; idx++)
clear_fixmap(idx);
#endif
/* Clean every zones */
memset(zones_size, 0, sizeof(zones_size));
#ifdef CONFIG_HIGHMEM
highmem_init();
zones_size[ZONE_DMA] = max_low_pfn;
zones_size[ZONE_HIGHMEM] = max_pfn;
#else
zones_size[ZONE_DMA] = max_pfn;
#endif
/* We don't have holes in memory map */
free_area_init_nodes(zones_size);
}
void __init setup_memory(void)
{
unsigned long map_size;
struct memblock_region *reg;
#ifndef CONFIG_MMU
u32 kernel_align_start, kernel_align_size;
/* Find main memory where is the kernel */
for_each_memblock(memory, reg) {
memory_start = (u32)reg->base;
lowmem_size = reg->size;
if ((memory_start <= (u32)_text) &&
((u32)_text <= (memory_start + lowmem_size - 1))) {
memory_size = lowmem_size;
PAGE_OFFSET = memory_start;
printk(KERN_INFO "%s: Main mem: 0x%x, "
"size 0x%08x\n", __func__, (u32) memory_start,
(u32) memory_size);
break;
}
}
if (!memory_start || !memory_size) {
panic("%s: Missing memory setting 0x%08x, size=0x%08x\n",
__func__, (u32) memory_start, (u32) memory_size);
}
/* reservation of region where is the kernel */
kernel_align_start = PAGE_DOWN((u32)_text);
/* ALIGN can be remove because _end in vmlinux.lds.S is align */
kernel_align_size = PAGE_UP((u32)klimit) - kernel_align_start;
printk(KERN_INFO "%s: kernel addr:0x%08x-0x%08x size=0x%08x\n",
__func__, kernel_align_start, kernel_align_start
+ kernel_align_size, kernel_align_size);
memblock_reserve(kernel_align_start, kernel_align_size);
#endif
/*
* Kernel:
* start: base phys address of kernel - page align
* end: base phys address of kernel - page align
*
* min_low_pfn - the first page (mm/bootmem.c - node_boot_start)
* max_low_pfn
* max_mapnr - the first unused page (mm/bootmem.c - node_low_pfn)
* num_physpages - number of all pages
*/
/* memory start is from the kernel end (aligned) to higher addr */
min_low_pfn = memory_start >> PAGE_SHIFT; /* minimum for allocation */
/* RAM is assumed contiguous */
num_physpages = max_mapnr = memory_size >> PAGE_SHIFT;
max_low_pfn = ((u64)memory_start + (u64)lowmem_size) >> PAGE_SHIFT;
max_pfn = ((u64)memory_start + (u64)memory_size) >> PAGE_SHIFT;
printk(KERN_INFO "%s: max_mapnr: %#lx\n", __func__, max_mapnr);
printk(KERN_INFO "%s: min_low_pfn: %#lx\n", __func__, min_low_pfn);
printk(KERN_INFO "%s: max_low_pfn: %#lx\n", __func__, max_low_pfn);
printk(KERN_INFO "%s: max_pfn: %#lx\n", __func__, max_pfn);
/*
* Find an area to use for the bootmem bitmap.
* We look for the first area which is at least
* 128kB in length (128kB is enough for a bitmap
* for 4GB of memory, using 4kB pages), plus 1 page
* (in case the address isn't page-aligned).
*/
map_size = init_bootmem_node(NODE_DATA(0),
PFN_UP(TOPHYS((u32)klimit)), min_low_pfn, max_low_pfn);
memblock_reserve(PFN_UP(TOPHYS((u32)klimit)) << PAGE_SHIFT, map_size);
/* Add active regions with valid PFNs */
for_each_memblock(memory, reg) {
unsigned long start_pfn, end_pfn;
start_pfn = memblock_region_memory_base_pfn(reg);
end_pfn = memblock_region_memory_end_pfn(reg);
memblock_set_node(start_pfn << PAGE_SHIFT,
(end_pfn - start_pfn) << PAGE_SHIFT, 0);
}
/* free bootmem is whole main memory */
free_bootmem_with_active_regions(0, max_low_pfn);
/* reserve allocate blocks */
for_each_memblock(reserved, reg) {
unsigned long top = reg->base + reg->size - 1;
pr_debug("reserved - 0x%08x-0x%08x, %lx, %lx\n",
(u32) reg->base, (u32) reg->size, top,
memory_start + lowmem_size - 1);
if (top <= (memory_start + lowmem_size - 1)) {
reserve_bootmem(reg->base, reg->size, BOOTMEM_DEFAULT);
} else if (reg->base < (memory_start + lowmem_size - 1)) {
unsigned long trunc_size = memory_start + lowmem_size -
reg->base;
reserve_bootmem(reg->base, trunc_size, BOOTMEM_DEFAULT);
}
}
/* XXX need to clip this if using highmem? */
sparse_memory_present_with_active_regions(0);
#ifdef CONFIG_MMU
init_bootmem_done = 1;
#endif
paging_init();
}
void free_init_pages(char *what, unsigned long begin, unsigned long end)
{
unsigned long addr;
for (addr = begin; addr < end; addr += PAGE_SIZE) {
ClearPageReserved(virt_to_page(addr));
init_page_count(virt_to_page(addr));
free_page(addr);
totalram_pages++;
}
printk(KERN_INFO "Freeing %s: %ldk freed\n", what, (end - begin) >> 10);
}
#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",
(int)(pages * (PAGE_SIZE / 1024)));
}
#endif
void free_initmem(void)
{
free_init_pages("unused kernel memory",
(unsigned long)(&__init_begin),
(unsigned long)(&__init_end));
}
void __init mem_init(void)
{
pg_data_t *pgdat;
unsigned long reservedpages = 0, codesize, initsize, datasize, bsssize;
high_memory = (void *)__va(memory_start + lowmem_size - 1);
/* this will put all memory onto the freelists */
totalram_pages += free_all_bootmem();
for_each_online_pgdat(pgdat) {
unsigned long i;
struct page *page;
for (i = 0; i < pgdat->node_spanned_pages; i++) {
if (!pfn_valid(pgdat->node_start_pfn + i))
continue;
page = pgdat_page_nr(pgdat, i);
if (PageReserved(page))
reservedpages++;
}
}
#ifdef CONFIG_HIGHMEM
reservedpages -= highmem_setup();
#endif
codesize = (unsigned long)&_sdata - (unsigned long)&_stext;
datasize = (unsigned long)&_edata - (unsigned long)&_sdata;
initsize = (unsigned long)&__init_end - (unsigned long)&__init_begin;
bsssize = (unsigned long)&__bss_stop - (unsigned long)&__bss_start;
pr_info("Memory: %luk/%luk available (%luk kernel code, "
"%luk reserved, %luk data, %luk bss, %luk init)\n",
nr_free_pages() << (PAGE_SHIFT-10),
num_physpages << (PAGE_SHIFT-10),
codesize >> 10,
reservedpages << (PAGE_SHIFT-10),
datasize >> 10,
bsssize >> 10,
initsize >> 10);
#ifdef CONFIG_MMU
pr_info("Kernel virtual memory layout:\n");
pr_info(" * 0x%08lx..0x%08lx : fixmap\n", FIXADDR_START, FIXADDR_TOP);
#ifdef CONFIG_HIGHMEM
pr_info(" * 0x%08lx..0x%08lx : highmem PTEs\n",
PKMAP_BASE, PKMAP_ADDR(LAST_PKMAP));
#endif /* CONFIG_HIGHMEM */
pr_info(" * 0x%08lx..0x%08lx : early ioremap\n",
ioremap_bot, ioremap_base);
pr_info(" * 0x%08lx..0x%08lx : vmalloc & ioremap\n",
(unsigned long)VMALLOC_START, VMALLOC_END);
#endif
mem_init_done = 1;
}
#ifndef CONFIG_MMU
int page_is_ram(unsigned long pfn)
{
return __range_ok(pfn, 0);
}
#else
int page_is_ram(unsigned long pfn)
{
return pfn < max_low_pfn;
}
/*
* Check for command-line options that affect what MMU_init will do.
*/
static void mm_cmdline_setup(void)
{
unsigned long maxmem = 0;
char *p = cmd_line;
/* Look for mem= option on command line */
p = strstr(cmd_line, "mem=");
if (p) {
p += 4;
maxmem = memparse(p, &p);
if (maxmem && memory_size > maxmem) {
memory_size = maxmem;
memblock.memory.regions[0].size = memory_size;
}
}
}
/*
* MMU_init_hw does the chip-specific initialization of the MMU hardware.
*/
static void __init mmu_init_hw(void)
{
/*
* The Zone Protection Register (ZPR) defines how protection will
* be applied to every page which is a member of a given zone. At
* present, we utilize only two of the zones.
* The zone index bits (of ZSEL) in the PTE are used for software
* indicators, except the LSB. For user access, zone 1 is used,
* for kernel access, zone 0 is used. We set all but zone 1
* to zero, allowing only kernel access as indicated in the PTE.
* For zone 1, we set a 01 binary (a value of 10 will not work)
* to allow user access as indicated in the PTE. This also allows
* kernel access as indicated in the PTE.
*/
__asm__ __volatile__ ("ori r11, r0, 0x10000000;" \
"mts rzpr, r11;"
: : : "r11");
}
/*
* MMU_init sets up the basic memory mappings for the kernel,
* including both RAM and possibly some I/O regions,
* and sets up the page tables and the MMU hardware ready to go.
*/
/* called from head.S */
asmlinkage void __init mmu_init(void)
{
unsigned int kstart, ksize;
if (!memblock.reserved.cnt) {
printk(KERN_EMERG "Error memory count\n");
machine_restart(NULL);
}
if ((u32) memblock.memory.regions[0].size < 0x400000) {
printk(KERN_EMERG "Memory must be greater than 4MB\n");
machine_restart(NULL);
}
if ((u32) memblock.memory.regions[0].size < kernel_tlb) {
printk(KERN_EMERG "Kernel size is greater than memory node\n");
machine_restart(NULL);
}
/* Find main memory where the kernel is */
memory_start = (u32) memblock.memory.regions[0].base;
lowmem_size = memory_size = (u32) memblock.memory.regions[0].size;
if (lowmem_size > CONFIG_LOWMEM_SIZE) {
lowmem_size = CONFIG_LOWMEM_SIZE;
#ifndef CONFIG_HIGHMEM
memory_size = lowmem_size;
#endif
}
mm_cmdline_setup(); /* FIXME parse args from command line - not used */
/*
* Map out the kernel text/data/bss from the available physical
* memory.
*/
kstart = __pa(CONFIG_KERNEL_START); /* kernel start */
/* kernel size */
ksize = PAGE_ALIGN(((u32)_end - (u32)CONFIG_KERNEL_START));
memblock_reserve(kstart, ksize);
#if defined(CONFIG_BLK_DEV_INITRD)
/* Remove the init RAM disk from the available memory. */
/* if (initrd_start) {
mem_pieces_remove(&phys_avail, __pa(initrd_start),
initrd_end - initrd_start, 1);
}*/
#endif /* CONFIG_BLK_DEV_INITRD */
/* Initialize the MMU hardware */
mmu_init_hw();
/* Map in all of RAM starting at CONFIG_KERNEL_START */
mapin_ram();
/* Extend vmalloc and ioremap area as big as possible */
#ifdef CONFIG_HIGHMEM
ioremap_base = ioremap_bot = PKMAP_BASE;
#else
ioremap_base = ioremap_bot = FIXADDR_START;
#endif
/* Initialize the context management stuff */
mmu_context_init();
/* Shortly after that, the entire linear mapping will be available */
/* This will also cause that unflatten device tree will be allocated
* inside 768MB limit */
memblock_set_current_limit(memory_start + lowmem_size - 1);
}
/* This is only called until mem_init is done. */
void __init *early_get_page(void)
{
void *p;
if (init_bootmem_done) {
p = alloc_bootmem_pages(PAGE_SIZE);
} else {
/*
* Mem start + kernel_tlb -> here is limit
* because of mem mapping from head.S
*/
p = __va(memblock_alloc_base(PAGE_SIZE, PAGE_SIZE,
memory_start + kernel_tlb));
}
return p;
}
#endif /* CONFIG_MMU */
void * __init_refok alloc_maybe_bootmem(size_t size, gfp_t mask)
{
if (mem_init_done)
return kmalloc(size, mask);
else
return alloc_bootmem(size);
}
void * __init_refok zalloc_maybe_bootmem(size_t size, gfp_t mask)
{
void *p;
if (mem_init_done)
p = kzalloc(size, mask);
else {
p = alloc_bootmem(size);
if (p)
memset(p, 0, size);
}
return p;
}