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#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <asm/setup.h>
#include <asm/atarihw.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#if 0
struct stram_desc
{
unsigned first:1;
unsigned last:1;
unsigned alloced:1;
unsigned length:24;
};
#define DP(ptr) ((struct stram_desc *) (ptr))
static unsigned long stramsize;
static unsigned long stramaddr;
void
atari_stram_init (void)
{
struct stram_desc *dp;
stramaddr = atari_stram_start;
stramsize = atari_stram_size;
/* initialize start boundary */
dp = DP (stramaddr);
dp->first = 1;
dp->alloced = 0;
dp->length = stramsize - 2 * sizeof (*dp);
/* initialize end boundary */
dp = DP (stramaddr + stramsize) - 1;
dp->last = 1;
dp->alloced = 0;
dp->length = stramsize - 2 * sizeof (*dp);
#ifdef DEBUG
printk ("stram end boundary is %p, length is %d\n", dp,
dp->length);
#endif
}
void *
atari_stram_alloc (long size)
{
/* last chunk */
struct stram_desc *dp;
void *ptr;
/* round off */
size = (size + 3) & ~3;
#ifdef DEBUG
printk ("stram_alloc: allocate %ld bytes\n", size);
#endif
/*
* get pointer to descriptor for last chunk by
* going backwards from end chunk
*/
dp = DP (stramaddr + stramsize) - 1;
dp = DP ((unsigned long) dp - dp->length) - 1;
while ((dp->alloced || dp->length < size) && !dp->first)
dp = DP ((unsigned long) dp - dp[-1].length) - 2;
if (dp->alloced || dp->length < size)
{
printk ("no stram available for %ld allocation\n", size);
return NULL;
}
if (dp->length < size + 2 * sizeof (*dp))
{
/* length too small to split; allocate the whole thing */
dp->alloced = 1;
ptr = (void *) (dp + 1);
dp = DP ((unsigned long) ptr + dp->length);
dp->alloced = 1;
#ifdef DEBUG
printk ("stram_alloc: no split\n");
#endif
}
else
{
/* split the extent; use the end part */
long newsize = dp->length - (2 * sizeof (*dp) + size);
#ifdef DEBUG
printk ("stram_alloc: splitting %d to %ld\n", dp->length,
newsize);
#endif
dp->length = newsize;
dp = DP ((unsigned long) (dp + 1) + newsize);
dp->first = dp->last = 0;
dp->alloced = 0;
dp->length = newsize;
dp++;
dp->first = dp->last = 0;
dp->alloced = 1;
dp->length = size;
ptr = (void *) (dp + 1);
dp = DP ((unsigned long) ptr + size);
dp->alloced = 1;
dp->length = size;
}
#ifdef DEBUG
printk ("stram_alloc: returning %p\n", ptr);
#endif
return ptr;
}
void
atari_stram_free (void *ptr)
{
struct stram_desc *sdp = DP (ptr) - 1, *dp2;
struct stram_desc *edp = DP ((unsigned long) ptr + sdp->length);
/* deallocate the chunk */
sdp->alloced = edp->alloced = 0;
/* check if we should merge with the previous chunk */
if (!sdp->first && !sdp[-1].alloced)
{
dp2 = DP ((unsigned long) sdp - sdp[-1].length) - 2;
dp2->length += sdp->length + 2 * sizeof (*sdp);
edp->length = dp2->length;
sdp = dp2;
}
/* check if we should merge with the following chunk */
if (!edp->last && !edp[1].alloced)
{
dp2 = DP ((unsigned long) edp + edp[1].length) + 2;
dp2->length += edp->length + 2 * sizeof (*sdp);
sdp->length = dp2->length;
edp = dp2;
}
}
#else
#include <linux/mm.h>
#include <linux/init.h>
/* ++roman:
*
* New version of ST-Ram buffer allocation. Instead of using the
* 1 MB - 4 KB that remain when the 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.
*
* ToDo:
* Check the high level scsi code what is done when the
* UNCHECKED_ISA_DMA flag is set. It guess, it is just a test for adr
* < 16 Mega. There should be call to atari_stram_alloc() instead.
*
* Also ToDo:
* Go through head.S and delete parts no longer needed (transparent
* mapping of ST-Ram etc.)
*
*/
unsigned long rsvd_stram_beg, rsvd_stram_end;
/* Start and end of the reserved ST-Ram region */
static unsigned long stram_end;
/* Overall end of ST-Ram */
__initfunc(void atari_stram_init( void ))
{ int i;
for( i = 0; i < m68k_num_memory; ++i ) {
if (m68k_memory[i].addr == 0) {
rsvd_stram_beg = PTOV( 0x800 ); /* skip super-only first 2 KB! */
rsvd_stram_end = rsvd_stram_beg;
stram_end = rsvd_stram_beg - 0x800 + m68k_memory[i].size;
return;
}
}
/* Should never come here! (There is always ST-Ram!) */
}
void *atari_stram_alloc( long size, unsigned long *start_mem )
{
static int kernel_in_stram = -1;
void *adr = 0;
if (kernel_in_stram < 0)
kernel_in_stram = (PTOV( 0 ) == 0);
if (kernel_in_stram) {
/* Get memory from kernel data space */
adr = (void *) *start_mem;
*start_mem += size;
}
else {
/* Get memory from rsvd_stram_beg */
if (rsvd_stram_end + size < stram_end) {
adr = (void *) rsvd_stram_end;
rsvd_stram_end += size;
}
}
return( adr );
}
void atari_stram_free( void *ptr )
{
/* Sorry, this is a dummy. It isn't needed anyway. */
}
#endif
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