linux/arch/m68k/amiga/chipram.c

125 lines
2.6 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
** linux/amiga/chipram.c
**
** Modified 03-May-94 by Geert Uytterhoeven <geert@linux-m68k.org>
** - 64-bit aligned allocations for full AGA compatibility
**
** Rewritten 15/9/2000 by Geert to use resource management
*/
#include <linux/types.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/module.h>
#include <asm/atomic.h>
#include <asm/page.h>
#include <asm/amigahw.h>
unsigned long amiga_chip_size;
EXPORT_SYMBOL(amiga_chip_size);
static struct resource chipram_res = {
.name = "Chip RAM", .start = CHIP_PHYSADDR
};
static atomic_t chipavail;
void __init amiga_chip_init(void)
{
if (!AMIGAHW_PRESENT(CHIP_RAM))
return;
chipram_res.end = CHIP_PHYSADDR + amiga_chip_size - 1;
request_resource(&iomem_resource, &chipram_res);
atomic_set(&chipavail, amiga_chip_size);
}
void *amiga_chip_alloc(unsigned long size, const char *name)
{
struct resource *res;
void *p;
res = kzalloc(sizeof(struct resource), GFP_KERNEL);
if (!res)
return NULL;
res->name = name;
p = amiga_chip_alloc_res(size, res);
if (!p) {
kfree(res);
return NULL;
}
return p;
}
EXPORT_SYMBOL(amiga_chip_alloc);
/*
* Warning:
* amiga_chip_alloc_res is meant only for drivers that need to
* allocate Chip RAM before kmalloc() is functional. As a consequence,
* those drivers must not free that Chip RAM afterwards.
*/
void *amiga_chip_alloc_res(unsigned long size, struct resource *res)
{
int error;
/* round up */
size = PAGE_ALIGN(size);
pr_debug("amiga_chip_alloc_res: allocate %lu bytes\n", size);
error = allocate_resource(&chipram_res, res, size, 0, UINT_MAX,
PAGE_SIZE, NULL, NULL);
if (error < 0) {
pr_err("amiga_chip_alloc_res: allocate_resource() failed %d!\n",
error);
return NULL;
}
atomic_sub(size, &chipavail);
pr_debug("amiga_chip_alloc_res: returning %pR\n", res);
return ZTWO_VADDR(res->start);
}
void amiga_chip_free(void *ptr)
{
unsigned long start = ZTWO_PADDR(ptr);
struct resource *res;
unsigned long size;
res = lookup_resource(&chipram_res, start);
if (!res) {
pr_err("amiga_chip_free: trying to free nonexistent region at "
"%p\n", ptr);
return;
}
size = resource_size(res);
pr_debug("amiga_chip_free: free %lu bytes at %p\n", size, ptr);
atomic_add(size, &chipavail);
release_resource(res);
kfree(res);
}
EXPORT_SYMBOL(amiga_chip_free);
unsigned long amiga_chip_avail(void)
{
unsigned long n = atomic_read(&chipavail);
pr_debug("amiga_chip_avail : %lu bytes\n", n);
return n;
}
EXPORT_SYMBOL(amiga_chip_avail);