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f9c98d0287
Please, please now delete the Atari CONFIG_STRAM_SWAP code. It may be excellent and ingenious code, but its reference to swap_vfsmnt betrays that it hasn't been built since 2.5.1 (four years old come December), it's delving deep into matters which are the preserve of core mm code, its only purpose is to give the more conscientious mm guys an anxiety attack from time to time; yet we keep on breaking it more and more. If you want to use RAM for swap, then if the MTD driver does not already provide just what you need, I'm sure David could be persuaded to add the extra. But you'd also like to be able to allocate extents of that swap for other use: we can give you a core interface for that if you need. But unbuilt for four years suggests to me that there's no need at all. I cannot swear the patch below won't break your build, but believe so. Signed-off-by: Hugh Dickins <hugh@veritas.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
360 lines
9.2 KiB
C
360 lines
9.2 KiB
C
/*
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* arch/m68k/atari/stram.c: Functions for ST-RAM allocations
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*
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* Copyright 1994-97 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de>
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*
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* This file is subject to the terms and conditions of the GNU General Public
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* License. See the file COPYING in the main directory of this archive
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* for more details.
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*/
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#include <linux/config.h>
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#include <linux/types.h>
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#include <linux/kernel.h>
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#include <linux/mm.h>
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#include <linux/kdev_t.h>
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#include <linux/major.h>
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#include <linux/init.h>
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#include <linux/slab.h>
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#include <linux/vmalloc.h>
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#include <linux/pagemap.h>
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#include <linux/bootmem.h>
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#include <linux/mount.h>
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#include <linux/blkdev.h>
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#include <asm/setup.h>
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#include <asm/machdep.h>
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#include <asm/page.h>
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#include <asm/pgtable.h>
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#include <asm/atarihw.h>
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#include <asm/atari_stram.h>
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#include <asm/io.h>
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#include <asm/semaphore.h>
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#undef DEBUG
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#ifdef DEBUG
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#define DPRINTK(fmt,args...) printk( fmt, ##args )
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#else
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#define DPRINTK(fmt,args...)
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#endif
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#if defined(CONFIG_PROC_FS) && defined(CONFIG_STRAM_PROC)
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/* abbrev for the && above... */
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#define DO_PROC
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#include <linux/proc_fs.h>
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#endif
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/*
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* ++roman:
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*
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* New version of ST-Ram buffer allocation. Instead of using the
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* 1 MB - 4 KB that remain when the ST-Ram chunk starts at $1000
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* (1 MB granularity!), such buffers are reserved like this:
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*
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* - If the kernel resides in ST-Ram anyway, we can take the buffer
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* from behind the current kernel data space the normal way
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* (incrementing start_mem).
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*
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* - If the kernel is in TT-Ram, stram_init() initializes start and
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* end of the available region. Buffers are allocated from there
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* and mem_init() later marks the such used pages as reserved.
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* Since each TT-Ram chunk is at least 4 MB in size, I hope there
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* won't be an overrun of the ST-Ram region by normal kernel data
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* space.
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*
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* For that, ST-Ram may only be allocated while kernel initialization
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* is going on, or exactly: before mem_init() is called. There is also
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* no provision now for freeing ST-Ram buffers. It seems that isn't
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* really needed.
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*
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*/
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/* Start and end (virtual) of ST-RAM */
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static void *stram_start, *stram_end;
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/* set after memory_init() executed and allocations via start_mem aren't
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* possible anymore */
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static int mem_init_done;
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/* set if kernel is in ST-RAM */
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static int kernel_in_stram;
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typedef struct stram_block {
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struct stram_block *next;
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void *start;
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unsigned long size;
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unsigned flags;
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const char *owner;
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} BLOCK;
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/* values for flags field */
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#define BLOCK_FREE 0x01 /* free structure in the BLOCKs pool */
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#define BLOCK_KMALLOCED 0x02 /* structure allocated by kmalloc() */
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#define BLOCK_GFP 0x08 /* block allocated with __get_dma_pages() */
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/* list of allocated blocks */
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static BLOCK *alloc_list;
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/* We can't always use kmalloc() to allocate BLOCK structures, since
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* stram_alloc() can be called rather early. So we need some pool of
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* statically allocated structures. 20 of them is more than enough, so in most
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* cases we never should need to call kmalloc(). */
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#define N_STATIC_BLOCKS 20
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static BLOCK static_blocks[N_STATIC_BLOCKS];
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/***************************** Prototypes *****************************/
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static BLOCK *add_region( void *addr, unsigned long size );
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static BLOCK *find_region( void *addr );
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static int remove_region( BLOCK *block );
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/************************* End of Prototypes **************************/
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/* ------------------------------------------------------------------------ */
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/* Public Interface */
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/* ------------------------------------------------------------------------ */
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/*
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* This init function is called very early by atari/config.c
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* It initializes some internal variables needed for stram_alloc()
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*/
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void __init atari_stram_init(void)
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{
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int i;
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/* initialize static blocks */
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for( i = 0; i < N_STATIC_BLOCKS; ++i )
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static_blocks[i].flags = BLOCK_FREE;
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/* determine whether kernel code resides in ST-RAM (then ST-RAM is the
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* first memory block at virtual 0x0) */
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stram_start = phys_to_virt(0);
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kernel_in_stram = (stram_start == 0);
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for( i = 0; i < m68k_num_memory; ++i ) {
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if (m68k_memory[i].addr == 0) {
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/* skip first 2kB or page (supervisor-only!) */
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stram_end = stram_start + m68k_memory[i].size;
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return;
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}
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}
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/* Should never come here! (There is always ST-Ram!) */
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panic( "atari_stram_init: no ST-RAM found!" );
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}
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/*
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* This function is called from setup_arch() to reserve the pages needed for
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* ST-RAM management.
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*/
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void __init atari_stram_reserve_pages(void *start_mem)
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{
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/* always reserve first page of ST-RAM, the first 2 kB are
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* supervisor-only! */
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if (!kernel_in_stram)
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reserve_bootmem (0, PAGE_SIZE);
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}
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void atari_stram_mem_init_hook (void)
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{
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mem_init_done = 1;
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}
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/*
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* This is main public interface: somehow allocate a ST-RAM block
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*
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* - If we're before mem_init(), we have to make a static allocation. The
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* region is taken in the kernel data area (if the kernel is in ST-RAM) or
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* from the start of ST-RAM (if the kernel is in TT-RAM) and added to the
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* rsvd_stram_* region. The ST-RAM is somewhere in the middle of kernel
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* address space in the latter case.
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*
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* - If mem_init() already has been called, try with __get_dma_pages().
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* This has the disadvantage that it's very hard to get more than 1 page,
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* and it is likely to fail :-(
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*
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*/
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void *atari_stram_alloc(long size, const char *owner)
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{
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void *addr = NULL;
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BLOCK *block;
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int flags;
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DPRINTK("atari_stram_alloc(size=%08lx,owner=%s)\n", size, owner);
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if (!mem_init_done)
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return alloc_bootmem_low(size);
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else {
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/* After mem_init(): can only resort to __get_dma_pages() */
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addr = (void *)__get_dma_pages(GFP_KERNEL, get_order(size));
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flags = BLOCK_GFP;
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DPRINTK( "atari_stram_alloc: after mem_init, "
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"get_pages=%p\n", addr );
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}
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if (addr) {
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if (!(block = add_region( addr, size ))) {
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/* out of memory for BLOCK structure :-( */
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DPRINTK( "atari_stram_alloc: out of mem for BLOCK -- "
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"freeing again\n" );
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free_pages((unsigned long)addr, get_order(size));
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return( NULL );
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}
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block->owner = owner;
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block->flags |= flags;
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}
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return( addr );
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}
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void atari_stram_free( void *addr )
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{
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BLOCK *block;
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DPRINTK( "atari_stram_free(addr=%p)\n", addr );
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if (!(block = find_region( addr ))) {
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printk( KERN_ERR "Attempt to free non-allocated ST-RAM block at %p "
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"from %p\n", addr, __builtin_return_address(0) );
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return;
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}
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DPRINTK( "atari_stram_free: found block (%p): size=%08lx, owner=%s, "
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"flags=%02x\n", block, block->size, block->owner, block->flags );
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if (!(block->flags & BLOCK_GFP))
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goto fail;
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DPRINTK("atari_stram_free: is kmalloced, order_size=%d\n",
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get_order(block->size));
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free_pages((unsigned long)addr, get_order(block->size));
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remove_region( block );
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return;
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fail:
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printk( KERN_ERR "atari_stram_free: cannot free block at %p "
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"(called from %p)\n", addr, __builtin_return_address(0) );
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}
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/* ------------------------------------------------------------------------ */
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/* Region Management */
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/* ------------------------------------------------------------------------ */
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/* insert a region into the alloced list (sorted) */
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static BLOCK *add_region( void *addr, unsigned long size )
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{
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BLOCK **p, *n = NULL;
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int i;
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for( i = 0; i < N_STATIC_BLOCKS; ++i ) {
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if (static_blocks[i].flags & BLOCK_FREE) {
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n = &static_blocks[i];
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n->flags = 0;
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break;
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}
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}
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if (!n && mem_init_done) {
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/* if statics block pool exhausted and we can call kmalloc() already
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* (after mem_init()), try that */
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n = kmalloc( sizeof(BLOCK), GFP_KERNEL );
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if (n)
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n->flags = BLOCK_KMALLOCED;
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}
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if (!n) {
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printk( KERN_ERR "Out of memory for ST-RAM descriptor blocks\n" );
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return( NULL );
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}
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n->start = addr;
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n->size = size;
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for( p = &alloc_list; *p; p = &((*p)->next) )
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if ((*p)->start > addr) break;
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n->next = *p;
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*p = n;
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return( n );
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}
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/* find a region (by start addr) in the alloced list */
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static BLOCK *find_region( void *addr )
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{
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BLOCK *p;
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for( p = alloc_list; p; p = p->next ) {
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if (p->start == addr)
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return( p );
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if (p->start > addr)
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break;
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}
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return( NULL );
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}
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/* remove a block from the alloced list */
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static int remove_region( BLOCK *block )
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{
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BLOCK **p;
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for( p = &alloc_list; *p; p = &((*p)->next) )
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if (*p == block) break;
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if (!*p)
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return( 0 );
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*p = block->next;
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if (block->flags & BLOCK_KMALLOCED)
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kfree( block );
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else
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block->flags |= BLOCK_FREE;
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return( 1 );
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}
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/* ------------------------------------------------------------------------ */
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/* /proc statistics file stuff */
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/* ------------------------------------------------------------------------ */
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#ifdef DO_PROC
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#define PRINT_PROC(fmt,args...) len += sprintf( buf+len, fmt, ##args )
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int get_stram_list( char *buf )
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{
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int len = 0;
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BLOCK *p;
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PRINT_PROC("Total ST-RAM: %8u kB\n",
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(stram_end - stram_start) >> 10);
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PRINT_PROC( "Allocated regions:\n" );
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for( p = alloc_list; p; p = p->next ) {
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if (len + 50 >= PAGE_SIZE)
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break;
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PRINT_PROC("0x%08lx-0x%08lx: %s (",
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virt_to_phys(p->start),
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virt_to_phys(p->start+p->size-1),
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p->owner);
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if (p->flags & BLOCK_GFP)
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PRINT_PROC( "page-alloced)\n" );
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else
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PRINT_PROC( "??)\n" );
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}
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return( len );
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}
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#endif
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/*
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* Local variables:
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* c-indent-level: 4
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* tab-width: 4
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* End:
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*/
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