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
  24 unsigned long amiga_chip_size;
  25 EXPORT_SYMBOL(amiga_chip_size);
  26
  27 static struct resource chipram_res = {
  28         .name = "Chip RAM", .start = CHIP_PHYSADDR
  29 };
  30 static atomic_t chipavail;
  31
  32
  33 void __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
  45 void *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 }
  63 EXPORT_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
  73 void *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
  94 void 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 }
 113 EXPORT_SYMBOL(amiga_chip_free);
 114
 115
 116 unsigned 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 }
 123 EXPORT_SYMBOL(amiga_chip_avail);
 124