+++ /dev/null
-/*
- * allocator.c -- allocate after high_memory, if available
- *
- * NOTE: this is different from my previous allocator, the one that
- * assembles pages, which revealed itself both slow and unreliable.
- *
- * Copyright (C) 1998 rubini@linux.it (Alessandro Rubini)
- *
- * 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.
- *
-
--- Changes --
-
- Date Programmer Description of changes made
- -------------------------------------------------------------------
- 02-Aug-2002 NJC allocator now steps in 1MB increments, rather
- than doubling its size each time.
- Also, allocator_init(u32 *) now returns
- (in the first arg) the size of the free
- space. This is no longer consistent with
- using the allocator as a module, and some changes
- may be necessary for that purpose. This was
- designed to work with the DT3155 driver, in
- stand alone mode only!!!
- 26-Oct-2009 SS Port to 2.6.30 kernel.
- */
-
-
-#ifndef __KERNEL__
-# define __KERNEL__
-#endif
-#ifndef MODULE
-# define MODULE
-#endif
-
-
-#include <linux/sched.h>
-#include <linux/kernel.h>
-#include <linux/fs.h>
-#include <linux/proc_fs.h>
-#include <linux/errno.h>
-#include <linux/types.h>
-#include <linux/mm.h> /* PAGE_ALIGN() */
-#include <linux/io.h>
-#include <linux/slab.h>
-
-#include <asm/page.h>
-
-#include "allocator.h"
-
-/*#define ALL_DEBUG*/
-#define ALL_MSG "allocator: "
-
-#undef PDEBUG /* undef it, just in case */
-#ifdef ALL_DEBUG
-# define __static
-# define DUMP_LIST() dump_list()
-# ifdef __KERNEL__
- /* This one if debugging is on, and kernel space */
-# define PDEBUG(fmt, args...) printk(KERN_DEBUG ALL_MSG fmt, ## args)
-# else
- /* This one for user space */
-# define PDEBUG(fmt, args...) fprintf(stderr, fmt, ## args)
-# endif
-#else
-# define PDEBUG(fmt, args...) /* not debugging: nothing */
-# define DUMP_LIST()
-# define __static static
-#endif
-
-#undef PDEBUGG
-#define PDEBUGG(fmt, args...)
-/*#define PDEBUGG(fmt, args...) printk( KERN_DEBUG ALL_MSG fmt, ## args)*/
-
-
-static int allocator_himem = 1; /* 0 = probe, pos. = megs, neg. = disable */
-static int allocator_step = 1; /* This is the step size in MB */
-static int allocator_probe = 1; /* This is a flag -- 1=probe, 0=don't probe */
-
-static unsigned long allocator_buffer; /* physical address */
-static unsigned long allocator_buffer_size; /* kilobytes */
-
-/*
- * The allocator keeps a list of DMA areas, so multiple devices
- * can coexist. The list is kept sorted by address
- */
-
-struct allocator_struct {
- unsigned long address;
- unsigned long size;
- struct allocator_struct *next;
-};
-
-static struct allocator_struct *allocator_list;
-
-#ifdef ALL_DEBUG
-static int dump_list(void)
-{
- struct allocator_struct *ptr;
-
- PDEBUG("Current list:\n");
- for (ptr = allocator_list; ptr; ptr = ptr->next)
- PDEBUG("0x%08lx (size %likB)\n", ptr->address, ptr->size>>10);
- return 0;
-}
-#endif
-
-/* ========================================================================
- * This function is the actual allocator.
- *
- * If space is available in high memory (as detected at load time), that
- * one is returned. The return value is a physical address (i.e., it can
- * be used straight ahead for DMA, but needs remapping for program use).
- */
-
-unsigned long allocator_allocate_dma(unsigned long kilobytes, gfp_t flags)
-{
- struct allocator_struct *ptr = allocator_list, *newptr;
- unsigned long bytes = kilobytes << 10;
-
- /* check if high memory is available */
- if (!allocator_buffer)
- return 0;
-
- /* Round it to a multiple of the pagesize */
- bytes = PAGE_ALIGN(bytes);
- PDEBUG("request for %li bytes\n", bytes);
-
- while (ptr && ptr->next) {
- if (ptr->next->address - (ptr->address + ptr->size) >= bytes)
- break; /* enough space */
- ptr = ptr->next;
- }
- if (!ptr->next) {
- DUMP_LIST();
- PDEBUG("alloc failed\n");
- return 0; /* end of list */
- }
- newptr = kmalloc(sizeof(struct allocator_struct), flags);
- if (!newptr)
- return 0;
-
- /* ok, now stick it after ptr */
- newptr->address = ptr->address + ptr->size;
- newptr->size = bytes;
- newptr->next = ptr->next;
- ptr->next = newptr;
-
- DUMP_LIST();
- PDEBUG("returning 0x%08lx\n", newptr->address);
- return newptr->address;
-}
-
-int allocator_free_dma(unsigned long address)
-{
- struct allocator_struct *ptr = allocator_list, *prev;
-
- while (ptr && ptr->next) {
- if (ptr->next->address == address)
- break;
- ptr = ptr->next;
- }
- /* the one being freed is ptr->next */
- prev = ptr; ptr = ptr->next;
-
- if (!ptr) {
- pr_err(ALL_MSG "free_dma but add. not allocated\n");
- return -EINVAL;
- }
- PDEBUGG("freeing: %08lx (%li) next %08lx\n", ptr->address, ptr->size,
- ptr->next->address);
- prev->next = ptr->next;
- kfree(ptr);
-
- /* dump_list(); */
- return 0;
-}
-
-/* ========================================================================
- * Init and cleanup
- *
- * On cleanup everything is released. If the list is not empty, that a
- * problem of our clients
- */
-int allocator_init(u32 *allocator_max)
-{
- /* check how much free memory is there */
- void *remapped;
- unsigned long max;
- unsigned long trial_size = allocator_himem<<20;
- unsigned long last_trial = 0;
- unsigned long step = allocator_step<<20;
- unsigned long i = 0;
- struct allocator_struct *head, *tail;
- char test_string[] = "0123456789abcde"; /* 16 bytes */
-
- PDEBUGG("himem = %i\n", allocator_himem);
- if (allocator_himem < 0) /* don't even try */
- return -EINVAL;
-
- if (!trial_size)
- trial_size = 1<<20; /* not specified: try one meg */
-
- while (1) {
- remapped = ioremap(__pa(high_memory), trial_size);
- if (!remapped) {
- PDEBUGG("%li megs failed!\n", trial_size>>20);
- break;
- }
- PDEBUGG("Trying %li megs (at %p, %p)\n", trial_size>>20,
- (void *)__pa(high_memory), remapped);
- for (i = last_trial; i < trial_size; i += 16) {
- strcpy((char *)(remapped)+i, test_string);
- if (strcmp((char *)(remapped)+i, test_string))
- break;
- }
- iounmap((void *)remapped);
- schedule();
- last_trial = trial_size;
- if (i == trial_size)
- trial_size += step; /* increment, if all went well */
- else {
- PDEBUGG("%li megs copy test failed!\n", trial_size>>20);
- break;
- }
- if (!allocator_probe)
- break;
- }
- PDEBUG("%li megs (%li k, %li b)\n", i>>20, i>>10, i);
- allocator_buffer_size = i>>10; /* kilobytes */
- allocator_buffer = __pa(high_memory);
- if (!allocator_buffer_size) {
- printk(KERN_WARNING ALL_MSG "no free high memory to use\n");
- return -ENOMEM;
- }
-
- /*
- * to simplify things, always have two cells in the list:
- * the first and the last. This avoids some conditionals and
- * extra code when allocating and deallocating: we only play
- * in the middle of the list
- */
- head = kmalloc(sizeof(struct allocator_struct), GFP_KERNEL);
- if (!head)
- return -ENOMEM;
- tail = kmalloc(sizeof(struct allocator_struct), GFP_KERNEL);
- if (!tail) {
- kfree(head);
- return -ENOMEM;
- }
-
- max = allocator_buffer_size<<10;
-
- head->size = tail->size = 0;
- head->address = allocator_buffer;
- tail->address = allocator_buffer + max;
- head->next = tail;
- tail->next = NULL;
- allocator_list = head;
-
- /* Back to the user code, in KB */
- *allocator_max = allocator_buffer_size;
-
- return 0; /* ok, ready */
-}
-
-void allocator_cleanup(void)
-{
- struct allocator_struct *ptr, *next;
-
- for (ptr = allocator_list; ptr; ptr = next) {
- next = ptr->next;
- PDEBUG("freeing list: 0x%08lx\n", ptr->address);
- kfree(ptr);
- }
-
- allocator_buffer = 0;
- allocator_buffer_size = 0;
- allocator_list = NULL;
-}
-
-
git.openpandora.org / pandora-kernel.git / blobdiff