diff -urN linux-2.6.32-rc8-lcrs-orig/arch/x86/Kconfig linux-2.6.32-rc8-lcrs/arch/x86/Kconfig --- linux-2.6.32-rc8-lcrs-orig/arch/x86/Kconfig 2009-11-19 17:32:38.000000000 -0500 +++ linux-2.6.32-rc8-lcrs/arch/x86/Kconfig 2009-11-24 05:15:51.000000000 -0500 @@ -1814,6 +1814,15 @@ endmenu +config BIGPHYS_AREA + bool "Support for big physical area reservation" + depends on X86_32 + ---help--- + Enables kernel support for reserving large areas of physical memory + at boot-time for use by certain device drivers (such as video + framegrabbers, etc.) which require it. To use this feature, boot + the kernel with the boot-time option 'bigphysarea=nnn' where + 'nnn' is the number of pages (a page is usually 4K) to reserve. menu "Bus options (PCI etc.)" diff -urN linux-2.6.32-rc8-lcrs-orig/Documentation/bigphysarea.txt linux-2.6.32-rc8-lcrs/Documentation/bigphysarea.txt --- linux-2.6.32-rc8-lcrs-orig/Documentation/bigphysarea.txt 1969-12-31 19:00:00.000000000 -0500 +++ linux-2.6.32-rc8-lcrs/Documentation/bigphysarea.txt 2009-11-24 05:15:51.000000000 -0500 @@ -0,0 +1,62 @@ +Bigphysarea +=========== + +This set of functions give you the ability to allocate big +continuous (DMAable) memory for the entire runtime of Linux. +Big meaning here more than 128KB, the maximum allocation +limit of kmalloc(). Due to fragmentation reasons kmalloc() +is unable to garantee allocs of this order during a prolonged +run of the kernel. This new pool of memory blob can be used +during the initialization or use of soundcards of framegrabbers +which are designed without DMA scatter-gatter capabilities. + +Enjoy + + +How to start +============ +First add bigphysarea= to the +commandline of your kernel. Either do this by adding an +append= line to your /etc/lilo/conf setup or use some +magic marker... +After booting the new kernel there should be a /proc/bigphysarea +file telling your how many blocks/bytes are available. + +The interface description +========================= +The big physical area is mainly managed by two functions. The first one, + +caddr_t bigphysarea_alloc_pages(int count, int align, int priority) + +allocates 'count' pages. The pages are aligned so that there base +address is a multiple of 'PAGE_SIZE * align'. If you don't need more +than page alignment, set 'align' to 0 or 1. 'priority' has the same +meaning as in kmalloc, it can be GFP_ATOMIC (for calls from interrupt +handlers) or GFP_KERNEL (for usual calls). The base address of the +allocated area is returned. + +Allocation can fail for two reasons, in both cases NULL is +returned. First, the physical area is scattered too much or there is +not enough memory, second it is not possible to allocate some memory +with kmalloc for administration of the physical area (very unlikely). + +To free an allocated area, just call + +void bigphysarea_free_pages(caddr_t base) + +with 'base' set to the value returned by 'bigphysarea_alloc_pages'. + +An example how to use this functions can be found in 'module.c'. + +There is still the old interface introduced by M. Welsh: + +caddr_t bigphysarea_alloc(int size) +void bigphysarea_free(caddr_t addr, int size) + +The first function allocates 'size' bytes physically continous +memory. To free the area, bigphysarea_free with a pointer to the area +and its size has to be called. Due to a new allocation algorithm, the +size parameter is no longer really needed when freeing an area. + +In the current version it is not safe to call any of the functions +from an interrupt handler. diff -urN linux-2.6.32-rc8-lcrs-orig/include/linux/bigphysarea.h linux-2.6.32-rc8-lcrs/include/linux/bigphysarea.h --- linux-2.6.32-rc8-lcrs-orig/include/linux/bigphysarea.h 1969-12-31 19:00:00.000000000 -0500 +++ linux-2.6.32-rc8-lcrs/include/linux/bigphysarea.h 2009-11-24 05:15:51.000000000 -0500 @@ -0,0 +1,29 @@ +/* linux/mm/bigphysarea.h, M. Welsh (mdw@cs.cornell.edu) + * Copyright (c) 1996 by Matt Welsh. + * Extended by Roger Butenuth (butenuth@uni-paderborn.de), October 1997 + * Extended for linux-2.1.121 till 2.4.0 (June 2000) + * by Pauline Middelink + * + * This is a set of routines which allow you to reserve a large (?) + * amount of physical memory at boot-time, which can be allocated/deallocated + * by drivers. This memory is intended to be used for devices such as + * video framegrabbers which need a lot of physical RAM (above the amount + * allocated by kmalloc). This is by no means efficient or recommended; + * to be used only in extreme circumstances. + * + */ + +#ifndef __LINUX_BIGPHYSAREA_H +#define __LINUX_BIGPHYSAREA_H + +#include + +/* original interface */ +extern caddr_t bigphysarea_alloc(int size); +extern void bigphysarea_free(caddr_t addr, int size); + +/* new interface */ +extern caddr_t bigphysarea_alloc_pages(int count, int align, int priority); +extern void bigphysarea_free_pages(caddr_t base); + +#endif // __LINUX_BIGPHYSAREA_H diff -urN linux-2.6.32-rc8-lcrs-orig/kernel/kallsyms.c linux-2.6.32-rc8-lcrs/kernel/kallsyms.c --- linux-2.6.32-rc8-lcrs-orig/kernel/kallsyms.c 2009-11-19 17:32:38.000000000 -0500 +++ linux-2.6.32-rc8-lcrs/kernel/kallsyms.c 2009-11-24 05:15:51.000000000 -0500 @@ -20,6 +20,9 @@ #include #include /* for cond_resched */ #include +#ifdef CONFIG_BIGPHYS_AREA +#include +#endif #include #include @@ -364,6 +367,13 @@ return len; } EXPORT_SYMBOL_GPL(sprint_symbol); +#ifdef CONFIG_BIGPHYS_AREA +EXPORT_SYMBOL(bigphysarea_alloc); +EXPORT_SYMBOL(bigphysarea_free); +EXPORT_SYMBOL(bigphysarea_alloc_pages); +EXPORT_SYMBOL(bigphysarea_free_pages); +#endif + /* Look up a kernel symbol and print it to the kernel messages. */ void __print_symbol(const char *fmt, unsigned long address) diff -urN linux-2.6.32-rc8-lcrs-orig/mm/bigphysarea.c linux-2.6.32-rc8-lcrs/mm/bigphysarea.c --- linux-2.6.32-rc8-lcrs-orig/mm/bigphysarea.c 1969-12-31 19:00:00.000000000 -0500 +++ linux-2.6.32-rc8-lcrs/mm/bigphysarea.c 2009-11-24 05:15:51.000000000 -0500 @@ -0,0 +1,373 @@ +/* linux/mm/bigphysarea.c, M. Welsh (mdw@cs.cornell.edu) + * Copyright (c) 1996 by Matt Welsh. + * Extended by Roger Butenuth (butenuth@uni-paderborn.de), October 1997 + * Extended for linux-2.1.121 till 2.4.0 (June 2000) + * by Pauline Middelink + * Extended and adapted for linux-2.6.x + * by J. Joe Feise + * + * This is a set of routines which allow you to reserve a large (?) + * amount of physical memory at boot-time, which can be allocated/deallocated + * by drivers. This memory is intended to be used for devices such as + * video framegrabbers which need a lot of physical RAM (above the amount + * allocated by kmalloc). This is by no means efficient or recommended; + * to be used only in extreme circumstances. + * + * 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, write to the Free Software + * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. + * + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +static int read_proc(char *page, char **start, off_t off, + int count, int *eof, void *data); + +typedef struct range_struct { + struct range_struct *next; + caddr_t base; /* base of allocated block */ + size_t size; /* size in bytes */ +} range_t; + +/* + * 0: nothing initialized + * 1: bigphysarea_pages initialized + * 2: free list initialized + */ +static int init_level = 0; +static int bigphysarea_pages = 0; +static caddr_t bigphysarea = 0; +static range_t *free_list = NULL; +static range_t *used_list = NULL; +static struct resource mem_resource = { "Bigphysarea", 0, 0, IORESOURCE_MEM|IORESOURCE_BUSY }; + +static +int __init bigphysarea_init(void) +{ + struct proc_dir_entry *res; + + if (bigphysarea_pages == 0 || bigphysarea == 0) + return -EINVAL; + + /* create /proc entry for it */ + res = create_proc_entry("bigphysarea", 0444, NULL); + if (!res) { + /* ohoh, no way to free the allocated memory! + * continue without proc support, it is not fatal in itself + */ +/* free_bootmem((unsigned long)bigphysarea>>PAGE_SHIFT,bigphysarea_pages<read_proc = read_proc; + + init_level = 1; + + printk(KERN_INFO "bigphysarea: Allocated %d pages at 0x%p.\n", + bigphysarea_pages, bigphysarea); + + return 0; +} + +__initcall(bigphysarea_init); + +/* + * call when 'bigphysarea=' is given on the commandline. + * + * Strangely, bootmem is still active during this call, but + * during the processing of the initcalls it isn't anymore! + * So we alloc the needed memory here instead of bigphysarea_init(). + */ +static +int __init bigphysarea_setup(char *str) +{ + int par; + if (get_option(&str,&par)) { + bigphysarea_pages = par; + // Alloc the memory + bigphysarea = alloc_bootmem_low_pages(bigphysarea_pages<next; + /* + * The free-list is sorted by address, search insertion point + * and insert block in free list. + */ + for (range_ptr = &free_list, prev = NULL; + *range_ptr != NULL; + prev = *range_ptr, range_ptr = &(*range_ptr)->next) + if ((*range_ptr)->base >= base) + break; + range->next = *range_ptr; + *range_ptr = range; + /* + * Concatenate free range with neighbors, if possible. + * Try for upper neighbor (next in list) first, then + * for lower neighbor (predecessor in list). + */ + if (range->next != NULL && + range->base + range->size == range->next->base) { + next = range->next; + range->size += range->next->size; + range->next = next->next; + kfree(next); + } + if (prev != NULL && + prev->base + prev->size == range->base) { + prev->size += prev->next->size; + prev->next = range->next; + kfree(range); + } +} + +caddr_t bigphysarea_alloc(int size) +{ + int pages = (size + PAGE_SIZE - 1) / PAGE_SIZE; + + return bigphysarea_alloc_pages(pages, 1, GFP_KERNEL); +} + +void bigphysarea_free(caddr_t addr, int size) +{ + (void)size; + bigphysarea_free_pages(addr); +} + +static int proc_calc_metrics(char *page, char **start, off_t off, + int count, int *eof, int len) +{ + if (len <= off+count) + *eof = 1; + *start = page + off; + len -= off; + if (len>count) + len = count; + if (len<0) + len = 0; + return len; +} + +static +int read_proc(char *page, char **start, off_t off, + int count, int *eof, void *data) +{ + int len; + range_t *ptr; + int free_count, free_total, free_max; + int used_count, used_total, used_max; + + if (init_level == 1) + init2(GFP_KERNEL); + + free_count = 0; + free_total = 0; + free_max = 0; + for (ptr = free_list; ptr != NULL; ptr = ptr->next) { + free_count++; + free_total += ptr->size; + if (ptr->size > free_max) + free_max = ptr->size; + } + + used_count = 0; + used_total = 0; + used_max = 0; + for (ptr = used_list; ptr != NULL; ptr = ptr->next) { + used_count++; + used_total += ptr->size; + if (ptr->size > used_max) + used_max = ptr->size; + } + + if (bigphysarea_pages == 0) { + len = sprintf(page, "No big physical area allocated!\n"); + } + else { + len = sprintf(page, + "Big physical area, size %ld kB\n" + " free list: used list:\n" + "number of blocks: %8d %8d\n" + "size of largest block: %8d kB %8d kB\n" + "total: %8d kB %8d kB\n", + bigphysarea_pages * PAGE_SIZE / 1024, + free_count, used_count, + free_max / 1024, used_max / 1024, + free_total / 1024, used_total /1024); + } + return proc_calc_metrics(page, start, off, count, eof, len); +} + diff -urN linux-2.6.32-rc8-lcrs-orig/mm/Makefile linux-2.6.32-rc8-lcrs/mm/Makefile --- linux-2.6.32-rc8-lcrs-orig/mm/Makefile 2009-11-19 17:32:38.000000000 -0500 +++ linux-2.6.32-rc8-lcrs/mm/Makefile 2009-11-24 05:15:51.000000000 -0500 @@ -45,3 +45,4 @@ obj-$(CONFIG_HWPOISON_INJECT) += hwpoison-inject.o obj-$(CONFIG_DEBUG_KMEMLEAK) += kmemleak.o obj-$(CONFIG_DEBUG_KMEMLEAK_TEST) += kmemleak-test.o +obj-$(CONFIG_BIGPHYS_AREA) += bigphysarea.o