minix/kernel/system/old/do_kmalloc.c
2005-04-21 14:53:53 +00:00

36 lines
1 KiB
C

/* The system call implemented in this file:
* m_type: SYS_KMALLOC
*
* The parameters for this system call are:
* m4_l2: MEM_CHUNK_SIZE (request a buffer of this size)
* m4_l1: MEM_CHUNK_BASE (return physical address on success)
*
* Author:
* Jorrit N. Herder <jnherder@cs.vu.nl>
*/
#include "../kernel.h"
#include "../system.h"
/*===========================================================================*
* do_kmalloc *
*===========================================================================*/
PUBLIC int do_kmalloc(m_ptr)
register message *m_ptr; /* pointer to request message */
{
/* Request a (DMA) buffer to be allocated in one of the memory chunks. */
phys_clicks tot_clicks;
struct memory *memp;
tot_clicks = (m_ptr->MEM_CHUNK_SIZE + CLICK_SIZE-1) >> CLICK_SHIFT;
memp = &mem[NR_MEMS];
while ((--memp)->size < tot_clicks) {
if (memp == mem) {
return(ENOMEM);
}
}
memp->size -= tot_clicks;
m_ptr->MEM_CHUNK_BASE = (memp->base + memp->size) << CLICK_SHIFT;
return(OK);
}