chipram.c

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/*
**  linux/amiga/chipram.c
**
**      Modified 03-May-94 by Geert Uytterhoeven <[email protected]>
**          - 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 (void *)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);