arch/m68k/amiga/chipram.c

   1 /*
   2 **  linux/amiga/chipram.c
   3 **
   4 **      Modified 03-May-94 by Geert Uytterhoeven <geert@linux-m68k.org>
   5 **          - 64-bit aligned allocations for full AGA compatibility
   6 **
   7 **      Rewritten 15/9/2000 by Geert to use resource management
   8 */
   9
  10 #include <linux/types.h>
  11 #include <linux/kernel.h>
  12 #include <linux/init.h>
  13 #include <linux/ioport.h>
  14 #include <linux/slab.h>
  15 #include <linux/string.h>
  16 #include <linux/module.h>
  17
  18 #include <asm/page.h>
  19 #include <asm/amigahw.h>
  20
  21 unsigned long amiga_chip_size;
  22 EXPORT_SYMBOL(amiga_chip_size);
  23
  24 static struct resource chipram_res = {
  25     .name = "Chip RAM", .start = CHIP_PHYSADDR
  26 };
  27 static unsigned long chipavail;
  28
  29
  30 void __init amiga_chip_init(void)
  31 {
  32     if (!AMIGAHW_PRESENT(CHIP_RAM))
  33         return;
  34
  35 #ifndef CONFIG_APUS_FAST_EXCEPT
  36     /*
  37      *  Remove the first 4 pages where PPC exception handlers will be located
  38      */
  39     amiga_chip_size -= 0x4000;
  40 #endif
  41     chipram_res.end = amiga_chip_size-1;
  42     request_resource(&iomem_resource, &chipram_res);
  43
  44     chipavail = amiga_chip_size;
  45 }
  46
  47
  48 void *amiga_chip_alloc(unsigned long size, const char *name)
  49 {
  50     struct resource *res;
  51
  52     /* round up */
  53     size = PAGE_ALIGN(size);
  54
  55 #ifdef DEBUG
  56     printk("amiga_chip_alloc: allocate %ld bytes\n", size);
  57 #endif
  58     res = kzalloc(sizeof(struct resource), GFP_KERNEL);
  59     if (!res)
  60         return NULL;
  61     res->name = name;
  62
  63     if (allocate_resource(&chipram_res, res, size, 0, UINT_MAX, PAGE_SIZE, NULL, NULL) < 0) {
  64         kfree(res);
  65         return NULL;
  66     }
  67     chipavail -= size;
  68 #ifdef DEBUG
  69     printk("amiga_chip_alloc: returning %lx\n", res->start);
  70 #endif
  71     return (void *)ZTWO_VADDR(res->start);
  72 }
  73 EXPORT_SYMBOL(amiga_chip_alloc);
  74
  75
  76     /*
  77      *  Warning:
  78      *  amiga_chip_alloc_res is meant only for drivers that need to allocate
  79      *  Chip RAM before kmalloc() is functional. As a consequence, those
  80      *  drivers must not free that Chip RAM afterwards.
  81      */
  82
  83 void * __init amiga_chip_alloc_res(unsigned long size, struct resource *res)
  84 {
  85     unsigned long start;
  86
  87     /* round up */
  88     size = PAGE_ALIGN(size);
  89     /* dmesg into chipmem prefers memory at the safe end */
  90     start = CHIP_PHYSADDR + chipavail - size;
  91
  92 #ifdef DEBUG
  93     printk("amiga_chip_alloc_res: allocate %ld bytes\n", size);
  94 #endif
  95     if (allocate_resource(&chipram_res, res, size, start, UINT_MAX, PAGE_SIZE, NULL, NULL) < 0) {
  96         printk("amiga_chip_alloc_res: first alloc failed!\n");
  97         if (allocate_resource(&chipram_res, res, size, 0, UINT_MAX, PAGE_SIZE, NULL, NULL) < 0)
  98             return NULL;
  99     }
 100     chipavail -= size;
 101 #ifdef DEBUG
 102     printk("amiga_chip_alloc_res: returning %lx\n", res->start);
 103 #endif
 104     return (void *)ZTWO_VADDR(res->start);
 105 }
 106
 107 void amiga_chip_free(void *ptr)
 108 {
 109     unsigned long start = ZTWO_PADDR(ptr);
 110     struct resource **p, *res;
 111     unsigned long size;
 112
 113     for (p = &chipram_res.child; (res = *p); p = &res->sibling) {
 114         if (res->start != start)
 115             continue;
 116         *p = res->sibling;
 117         size = res->end-start;
 118 #ifdef DEBUG
 119         printk("amiga_chip_free: free %ld bytes at %p\n", size, ptr);
 120 #endif
 121         chipavail += size;
 122         kfree(res);
 123         return;
 124     }
 125     printk("amiga_chip_free: trying to free nonexistent region at %p\n", ptr);
 126 }
 127 EXPORT_SYMBOL(amiga_chip_free);
 128
 129
 130 unsigned long amiga_chip_avail(void)
 131 {
 132 #ifdef DEBUG
 133         printk("amiga_chip_avail : %ld bytes\n", chipavail);
 134 #endif
 135         return chipavail;
 136 }
 137 EXPORT_SYMBOL(amiga_chip_avail);
 138