LXR linux/arch/m68k/amiga/chipram.c

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3**  linux/amiga/chipram.c
   4**
   5**      Modified 03-May-94 by Geert Uytterhoeven <geert@linux-m68k.org>
   6**          - 64-bit aligned allocations for full AGA compatibility
   7**
   8**      Rewritten 15/9/2000 by Geert to use resource management
   9*/
  10
  11#include <linux/types.h>
  12#include <linux/kernel.h>
  13#include <linux/mm.h>
  14#include <linux/init.h>
  15#include <linux/ioport.h>
  16#include <linux/slab.h>
  17#include <linux/string.h>
  18#include <linux/module.h>
  19
  20#include <asm/atomic.h>
  21#include <asm/page.h>
  22#include <asm/amigahw.h>
  23
  24unsigned long amiga_chip_size;
  25EXPORT_SYMBOL(amiga_chip_size);
  26
  27static struct resource chipram_res = {
  28        .name = "Chip RAM", .start = CHIP_PHYSADDR
  29};
  30static atomic_t chipavail;
  31
  32
  33void __init amiga_chip_init(void)
  34{
  35        if (!AMIGAHW_PRESENT(CHIP_RAM))
  36                return;
  37
  38        chipram_res.end = CHIP_PHYSADDR + amiga_chip_size - 1;
  39        request_resource(&iomem_resource, &chipram_res);
  40
  41        atomic_set(&chipavail, amiga_chip_size);
  42}
  43
  44
  45void *amiga_chip_alloc(unsigned long size, const char *name)
  46{
  47        struct resource *res;
  48        void *p;
  49
  50        res = kzalloc(sizeof(struct resource), GFP_KERNEL);
  51        if (!res)
  52                return NULL;
  53
  54        res->name = name;
  55        p = amiga_chip_alloc_res(size, res);
  56        if (!p) {
  57                kfree(res);
  58                return NULL;
  59        }
  60
  61        return p;
  62}
  63EXPORT_SYMBOL(amiga_chip_alloc);
  64
  65
  66        /*
  67         *  Warning:
  68         *  amiga_chip_alloc_res is meant only for drivers that need to
  69         *  allocate Chip RAM before kmalloc() is functional. As a consequence,
  70         *  those drivers must not free that Chip RAM afterwards.
  71         */
  72
  73void *amiga_chip_alloc_res(unsigned long size, struct resource *res)
  74{
  75        int error;
  76
  77        /* round up */
  78        size = PAGE_ALIGN(size);
  79
  80        pr_debug("amiga_chip_alloc_res: allocate %lu bytes\n", size);
  81        error = allocate_resource(&chipram_res, res, size, 0, UINT_MAX,
  82                                  PAGE_SIZE, NULL, NULL);
  83        if (error < 0) {
  84                pr_err("amiga_chip_alloc_res: allocate_resource() failed %d!\n",
  85                       error);
  86                return NULL;
  87        }
  88
  89        atomic_sub(size, &chipavail);
  90        pr_debug("amiga_chip_alloc_res: returning %pR\n", res);
  91        return ZTWO_VADDR(res->start);
  92}
  93
  94void amiga_chip_free(void *ptr)
  95{
  96        unsigned long start = ZTWO_PADDR(ptr);
  97        struct resource *res;
  98        unsigned long size;
  99
 100        res = lookup_resource(&chipram_res, start);
 101        if (!res) {
 102                pr_err("amiga_chip_free: trying to free nonexistent region at "
 103                       "%p\n", ptr);
 104                return;
 105        }
 106
 107        size = resource_size(res);
 108        pr_debug("amiga_chip_free: free %lu bytes at %p\n", size, ptr);
 109        atomic_add(size, &chipavail);
 110        release_resource(res);
 111        kfree(res);
 112}
 113EXPORT_SYMBOL(amiga_chip_free);
 114
 115
 116unsigned long amiga_chip_avail(void)
 117{
 118        unsigned long n = atomic_read(&chipavail);
 119
 120        pr_debug("amiga_chip_avail : %lu bytes\n", n);
 121        return n;
 122}
 123EXPORT_SYMBOL(amiga_chip_avail);
 124
 125