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m68k/atari: Reserve some ST-RAM early on for device buffer use

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Based on an original patch from Michael Schmitz:

Because mem_init() is now called before device init, devices that rely on
ST-RAM may find all ST-RAM already allocated to other users by the time
device init happens. In particular, a large initrd RAM disk may use up
enough of ST-RAM to cause atari_stram_alloc() to resort to
__get_dma_pages() allocation.

In the current state of Atari memory management, all of RAM is marked
DMA capable, so __get_dma_pages() may well return RAM that is not in actual
fact DMA capable. Using this for frame buffer or SCSI DMA buffer causes
subtle failure.

The ST-RAM allocator has been changed to allocate memory from a pool of
reserved ST-RAM of configurable size, set aside on ST-RAM init (i.e.
before mem_init()). As long as this pool is not exhausted, allocation of
real ST-RAM can be guaranteed.

Other changes:
  - Replace the custom allocator in the ST-RAM pool by the existing allocator
    in the resource subsystem,
  - Remove mem_init_done and its hook, as memory init is now done before
    device init,
  - Remove /proc/stram, as ST-RAM usage now shows up under /proc/iomem, e.g.

	005f2000-006f1fff : ST-RAM Pool
	  005f2000-0063dfff : atafb
	  0063e000-00641fff : ataflop
	  00642000-00642fff : SCSI

Signed-off-by: Michael Schmitz <schmitz@debian.org>
[Andreas Schwab <schwab@linux-m68k.org>: Use memparse()]
[Geert: Use the resource subsystem instead of a custom allocator]
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
This commit is contained in:
Michael Schmitz 2010-11-01 19:54:00 +01:00 committed by Geert Uytterhoeven
parent b7785e9543
commit 217bbd8188
4 changed files with 68 additions and 296 deletions
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6
arch/m68k/Kconfig.mmu
View File

@ -372,12 +372,6 @@ config AMIGA_PCMCIA
Include support in the kernel for pcmcia on Amiga 1200 and Amiga
600. If you intend to use pcmcia cards say Y; otherwise say N.
config STRAM_PROC
bool "ST-RAM statistics in /proc"
depends on ATARI
help
Say Y here to report ST-RAM usage statistics in /proc/stram.
config HEARTBEAT
bool "Use power LED as a heartbeat" if AMIGA || APOLLO || ATARI || MAC ||Q40
default y if !AMIGA && !APOLLO && !ATARI && !MAC && !Q40 && HP300

350
arch/m68k/atari/stram.c
View File

@ -1,5 +1,5 @@
/*
* arch/m68k/atari/stram.c: Functions for ST-RAM allocations
* Functions for ST-RAM allocations
*
* Copyright 1994-97 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de>
*
@ -30,91 +30,35 @@
#include <asm/atari_stram.h>
#include <asm/io.h>
#undef DEBUG
#ifdef DEBUG
#define DPRINTK(fmt,args...) printk( fmt, ##args )
#else
#define DPRINTK(fmt,args...)
#endif
#if defined(CONFIG_PROC_FS) && defined(CONFIG_STRAM_PROC)
/* abbrev for the && above... */
#define DO_PROC
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#endif
/*
* ++roman:
*
* New version of ST-Ram buffer allocation. Instead of using the
* 1 MB - 4 KB that remain when the ST-Ram chunk starts at $1000
* (1 MB granularity!), such buffers are reserved like this:
*
* - If the kernel resides in ST-Ram anyway, we can take the buffer
* from behind the current kernel data space the normal way
* (incrementing start_mem).
*
* - If the kernel is in TT-Ram, stram_init() initializes start and
* end of the available region. Buffers are allocated from there
* and mem_init() later marks the such used pages as reserved.
* Since each TT-Ram chunk is at least 4 MB in size, I hope there
* won't be an overrun of the ST-Ram region by normal kernel data
* space.
*
* For that, ST-Ram may only be allocated while kernel initialization
* is going on, or exactly: before mem_init() is called. There is also
* no provision now for freeing ST-Ram buffers. It seems that isn't
* really needed.
*
* The ST-RAM allocator allocates memory from a pool of reserved ST-RAM of
* configurable size, set aside on ST-RAM init.
* As long as this pool is not exhausted, allocation of real ST-RAM can be
* guaranteed.
*/
/* Start and end (virtual) of ST-RAM */
static void *stram_start, *stram_end;
/* set after memory_init() executed and allocations via start_mem aren't
* possible anymore */
static int mem_init_done;
/* set if kernel is in ST-RAM */
static int kernel_in_stram;
typedef struct stram_block {
struct stram_block *next;
void *start;
unsigned long size;
unsigned flags;
const char *owner;
} BLOCK;
static struct resource stram_pool = {
.name = "ST-RAM Pool"
};
/* values for flags field */
#define BLOCK_FREE 0x01 /* free structure in the BLOCKs pool */
#define BLOCK_KMALLOCED 0x02 /* structure allocated by kmalloc() */
#define BLOCK_GFP 0x08 /* block allocated with __get_dma_pages() */
static unsigned long pool_size = 1024*1024;
/* list of allocated blocks */
static BLOCK *alloc_list;
/* We can't always use kmalloc() to allocate BLOCK structures, since
* stram_alloc() can be called rather early. So we need some pool of
* statically allocated structures. 20 of them is more than enough, so in most
* cases we never should need to call kmalloc(). */
#define N_STATIC_BLOCKS 20
static BLOCK static_blocks[N_STATIC_BLOCKS];
static int __init atari_stram_setup(char *arg)
{
if (!MACH_IS_ATARI)
return 0;
/***************************** Prototypes *****************************/
pool_size = memparse(arg, NULL);
return 0;
}
static BLOCK *add_region( void *addr, unsigned long size );
static BLOCK *find_region( void *addr );
static int remove_region( BLOCK *block );
early_param("stram_pool", atari_stram_setup);
/************************* End of Prototypes **************************/
/* ------------------------------------------------------------------------ */
/* Public Interface */
/* ------------------------------------------------------------------------ */
/*
* This init function is called very early by atari/config.c
@ -123,25 +67,23 @@ static int remove_region( BLOCK *block );
void __init atari_stram_init(void)
{
int i;
void *stram_start;
/* initialize static blocks */
for( i = 0; i < N_STATIC_BLOCKS; ++i )
static_blocks[i].flags = BLOCK_FREE;
/* determine whether kernel code resides in ST-RAM (then ST-RAM is the
* first memory block at virtual 0x0) */
/*
* determine whether kernel code resides in ST-RAM
* (then ST-RAM is the first memory block at virtual 0x0)
*/
stram_start = phys_to_virt(0);
kernel_in_stram = (stram_start == 0);
for( i = 0; i < m68k_num_memory; ++i ) {
for (i = 0; i < m68k_num_memory; ++i) {
if (m68k_memory[i].addr == 0) {
/* skip first 2kB or page (supervisor-only!) */
stram_end = stram_start + m68k_memory[i].size;
return;
}
}
/* Should never come here! (There is always ST-Ram!) */
panic( "atari_stram_init: no ST-RAM found!" );
panic("atari_stram_init: no ST-RAM found!");
}
@ -151,226 +93,68 @@ void __init atari_stram_init(void)
*/
void __init atari_stram_reserve_pages(void *start_mem)
{
/* always reserve first page of ST-RAM, the first 2 kB are
* supervisor-only! */
/*
* always reserve first page of ST-RAM, the first 2 KiB are
* supervisor-only!
*/
if (!kernel_in_stram)
reserve_bootmem(0, PAGE_SIZE, BOOTMEM_DEFAULT);
}
stram_pool.start = (resource_size_t)alloc_bootmem_low_pages(pool_size);
stram_pool.end = stram_pool.start + pool_size - 1;
request_resource(&iomem_resource, &stram_pool);
void atari_stram_mem_init_hook (void)
{
mem_init_done = 1;
pr_debug("atari_stram pool: size = %lu bytes, resource = %pR\n",
pool_size, &stram_pool);
}
/*
* This is main public interface: somehow allocate a ST-RAM block
*
* - If we're before mem_init(), we have to make a static allocation. The
* region is taken in the kernel data area (if the kernel is in ST-RAM) or
* from the start of ST-RAM (if the kernel is in TT-RAM) and added to the
* rsvd_stram_* region. The ST-RAM is somewhere in the middle of kernel
* address space in the latter case.
*
* - If mem_init() already has been called, try with __get_dma_pages().
* This has the disadvantage that it's very hard to get more than 1 page,
* and it is likely to fail :-(
*
*/
void *atari_stram_alloc(long size, const char *owner)
void *atari_stram_alloc(unsigned long size, const char *owner)
{
void *addr = NULL;
BLOCK *block;
int flags;
struct resource *res;
int error;
DPRINTK("atari_stram_alloc(size=%08lx,owner=%s)\n", size, owner);
pr_debug("atari_stram_alloc: allocate %lu bytes\n", size);
if (!mem_init_done)
return alloc_bootmem_low(size);
else {
/* After mem_init(): can only resort to __get_dma_pages() */
addr = (void *)__get_dma_pages(GFP_KERNEL, get_order(size));
flags = BLOCK_GFP;
DPRINTK( "atari_stram_alloc: after mem_init, "
"get_pages=%p\n", addr );
/* round up */
size = PAGE_ALIGN(size);
res = kzalloc(sizeof(struct resource), GFP_KERNEL);
if (!res)
return NULL;
res->name = owner;
error = allocate_resource(&stram_pool, res, size, 0, UINT_MAX,
PAGE_SIZE, NULL, NULL);
if (error < 0) {
pr_err("atari_stram_alloc: allocate_resource() failed %d!\n",
error);
kfree(res);
return NULL;
}
if (addr) {
if (!(block = add_region( addr, size ))) {
/* out of memory for BLOCK structure :-( */
DPRINTK( "atari_stram_alloc: out of mem for BLOCK -- "
"freeing again\n" );
free_pages((unsigned long)addr, get_order(size));
return( NULL );
}
block->owner = owner;
block->flags |= flags;
}
return( addr );
pr_debug("atari_stram_alloc: returning %pR\n", res);
return (void *)res->start;
}
EXPORT_SYMBOL(atari_stram_alloc);
void atari_stram_free( void *addr )
void atari_stram_free(void *addr)
{
BLOCK *block;
unsigned long start = (unsigned long)addr;
struct resource *res;
unsigned long size;
DPRINTK( "atari_stram_free(addr=%p)\n", addr );
if (!(block = find_region( addr ))) {
printk( KERN_ERR "Attempt to free non-allocated ST-RAM block at %p "
"from %p\n", addr, __builtin_return_address(0) );
res = lookup_resource(&stram_pool, start);
if (!res) {
pr_err("atari_stram_free: trying to free nonexistent region "
"at %p\n", addr);
return;
}
DPRINTK( "atari_stram_free: found block (%p): size=%08lx, owner=%s, "
"flags=%02x\n", block, block->size, block->owner, block->flags );
if (!(block->flags & BLOCK_GFP))
goto fail;
DPRINTK("atari_stram_free: is kmalloced, order_size=%d\n",
get_order(block->size));
free_pages((unsigned long)addr, get_order(block->size));
remove_region( block );
return;
fail:
printk( KERN_ERR "atari_stram_free: cannot free block at %p "
"(called from %p)\n", addr, __builtin_return_address(0) );
size = resource_size(res);
pr_debug("atari_stram_free: free %lu bytes at %p\n", size, addr);
release_resource(res);
kfree(res);
}
EXPORT_SYMBOL(atari_stram_free);
/* ------------------------------------------------------------------------ */
/* Region Management */
/* ------------------------------------------------------------------------ */
/* insert a region into the alloced list (sorted) */
static BLOCK *add_region( void *addr, unsigned long size )
{
BLOCK **p, *n = NULL;
int i;
for( i = 0; i < N_STATIC_BLOCKS; ++i ) {
if (static_blocks[i].flags & BLOCK_FREE) {
n = &static_blocks[i];
n->flags = 0;
break;
}
}
if (!n && mem_init_done) {
/* if statics block pool exhausted and we can call kmalloc() already
* (after mem_init()), try that */
n = kmalloc( sizeof(BLOCK), GFP_KERNEL );
if (n)
n->flags = BLOCK_KMALLOCED;
}
if (!n) {
printk( KERN_ERR "Out of memory for ST-RAM descriptor blocks\n" );
return( NULL );
}
n->start = addr;
n->size = size;
for( p = &alloc_list; *p; p = &((*p)->next) )
if ((*p)->start > addr) break;
n->next = *p;
*p = n;
return( n );
}
/* find a region (by start addr) in the alloced list */
static BLOCK *find_region( void *addr )
{
BLOCK *p;
for( p = alloc_list; p; p = p->next ) {
if (p->start == addr)
return( p );
if (p->start > addr)
break;
}
return( NULL );
}
/* remove a block from the alloced list */
static int remove_region( BLOCK *block )
{
BLOCK **p;
for( p = &alloc_list; *p; p = &((*p)->next) )
if (*p == block) break;
if (!*p)
return( 0 );
*p = block->next;
if (block->flags & BLOCK_KMALLOCED)
kfree( block );
else
block->flags |= BLOCK_FREE;
return( 1 );
}
/* ------------------------------------------------------------------------ */
/* /proc statistics file stuff */
/* ------------------------------------------------------------------------ */
#ifdef DO_PROC
#define PRINT_PROC(fmt,args...) seq_printf( m, fmt, ##args )
static int stram_proc_show(struct seq_file *m, void *v)
{
BLOCK *p;
PRINT_PROC("Total ST-RAM: %8u kB\n",
(stram_end - stram_start) >> 10);
PRINT_PROC( "Allocated regions:\n" );
for( p = alloc_list; p; p = p->next ) {
PRINT_PROC("0x%08lx-0x%08lx: %s (",
virt_to_phys(p->start),
virt_to_phys(p->start+p->size-1),
p->owner);
if (p->flags & BLOCK_GFP)
PRINT_PROC( "page-alloced)\n" );
else
PRINT_PROC( "??)\n" );
}
return 0;
}
static int stram_proc_open(struct inode *inode, struct file *file)
{
return single_open(file, stram_proc_show, NULL);
}
static const struct file_operations stram_proc_fops = {
.open = stram_proc_open,
.read = seq_read,
.llseek = seq_lseek,
.release = single_release,
};
static int __init proc_stram_init(void)
{
proc_create("stram", 0, NULL, &stram_proc_fops);
return 0;
}
module_init(proc_stram_init);
#endif
/*
* Local variables:
* c-indent-level: 4
* tab-width: 4
* End:
*/

3
arch/m68k/include/asm/atari_stram.h
View File

@ -6,12 +6,11 @@
*/
/* public interface */
void *atari_stram_alloc(long size, const char *owner);
void *atari_stram_alloc(unsigned long size, const char *owner);
void atari_stram_free(void *);
/* functions called internally by other parts of the kernel */
void atari_stram_init(void);
void atari_stram_reserve_pages(void *start_mem);
void atari_stram_mem_init_hook (void);
#endif /*_M68K_ATARI_STRAM_H */

5
arch/m68k/mm/init_mm.c
View File

@ -83,11 +83,6 @@ void __init mem_init(void)
int initpages = 0;
int i;
#ifdef CONFIG_ATARI
if (MACH_IS_ATARI)
atari_stram_mem_init_hook();
#endif
/* this will put all memory onto the freelists */
totalram_pages = num_physpages = 0;
for_each_online_pgdat(pgdat) {