1 /* 2 * Functions for ST-RAM allocations 3 * 4 * Copyright 1994-97 Roman Hodek <Roman.Hodek@informatik.uni-erlangen.de> 5 * 6 * This file is subject to the terms and conditions of the GNU General Public 7 * License. See the file COPYING in the main directory of this archive 8 * for more details. 9 */ 10 11 #include <linux/types.h> 12 #include <linux/kernel.h> 13 #include <linux/mm.h> 14 #include <linux/kdev_t.h> 15 #include <linux/major.h> 16 #include <linux/init.h> 17 #include <linux/slab.h> 18 #include <linux/vmalloc.h> 19 #include <linux/pagemap.h> 20 #include <linux/bootmem.h> 21 #include <linux/mount.h> 22 #include <linux/blkdev.h> 23 #include <linux/module.h> 24 25 #include <asm/setup.h> 26 #include <asm/machdep.h> 27 #include <asm/page.h> 28 #include <asm/pgtable.h> 29 #include <asm/atarihw.h> 30 #include <asm/atari_stram.h> 31 #include <asm/io.h> 32 33 34 /* 35 * The ST-RAM allocator allocates memory from a pool of reserved ST-RAM of 36 * configurable size, set aside on ST-RAM init. 37 * As long as this pool is not exhausted, allocation of real ST-RAM can be 38 * guaranteed. 39 */ 40 41 /* set if kernel is in ST-RAM */ 42 static int kernel_in_stram; 43 44 static struct resource stram_pool = { 45 .name = "ST-RAM Pool" 46 }; 47 48 static unsigned long pool_size = 1024*1024; 49 50 51 static int __init atari_stram_setup(char *arg) 52 { 53 if (!MACH_IS_ATARI) 54 return 0; 55 56 pool_size = memparse(arg, NULL); 57 return 0; 58 } 59 60 early_param("stram_pool", atari_stram_setup); 61 62 63 /* 64 * This init function is called very early by atari/config.c 65 * It initializes some internal variables needed for stram_alloc() 66 */ 67 void __init atari_stram_init(void) 68 { 69 int i; 70 void *stram_start; 71 72 /* 73 * determine whether kernel code resides in ST-RAM 74 * (then ST-RAM is the first memory block at virtual 0x0) 75 */ 76 stram_start = phys_to_virt(0); 77 kernel_in_stram = (stram_start == 0); 78 79 for (i = 0; i < m68k_num_memory; ++i) { 80 if (m68k_memory[i].addr == 0) { 81 return; 82 } 83 } 84 85 /* Should never come here! (There is always ST-Ram!) */ 86 panic("atari_stram_init: no ST-RAM found!"); 87 } 88 89 90 /* 91 * This function is called from setup_arch() to reserve the pages needed for 92 * ST-RAM management. 93 */ 94 void __init atari_stram_reserve_pages(void *start_mem) 95 { 96 /* 97 * always reserve first page of ST-RAM, the first 2 KiB are 98 * supervisor-only! 99 */ 100 if (!kernel_in_stram) 101 reserve_bootmem(0, PAGE_SIZE, BOOTMEM_DEFAULT); 102 103 stram_pool.start = (resource_size_t)alloc_bootmem_low_pages(pool_size); 104 stram_pool.end = stram_pool.start + pool_size - 1; 105 request_resource(&iomem_resource, &stram_pool); 106 107 pr_debug("atari_stram pool: size = %lu bytes, resource = %pR\n", 108 pool_size, &stram_pool); 109 } 110 111 112 void *atari_stram_alloc(unsigned long size, const char *owner) 113 { 114 struct resource *res; 115 int error; 116 117 pr_debug("atari_stram_alloc: allocate %lu bytes\n", size); 118 119 /* round up */ 120 size = PAGE_ALIGN(size); 121 122 res = kzalloc(sizeof(struct resource), GFP_KERNEL); 123 if (!res) 124 return NULL; 125 126 res->name = owner; 127 error = allocate_resource(&stram_pool, res, size, 0, UINT_MAX, 128 PAGE_SIZE, NULL, NULL); 129 if (error < 0) { 130 pr_err("atari_stram_alloc: allocate_resource() failed %d!\n", 131 error); 132 kfree(res); 133 return NULL; 134 } 135 136 pr_debug("atari_stram_alloc: returning %pR\n", res); 137 return (void *)res->start; 138 } 139 EXPORT_SYMBOL(atari_stram_alloc); 140 141 142 void atari_stram_free(void *addr) 143 { 144 unsigned long start = (unsigned long)addr; 145 struct resource *res; 146 unsigned long size; 147 148 res = lookup_resource(&stram_pool, start); 149 if (!res) { 150 pr_err("atari_stram_free: trying to free nonexistent region " 151 "at %p\n", addr); 152 return; 153 } 154 155 size = resource_size(res); 156 pr_debug("atari_stram_free: free %lu bytes at %p\n", size, addr); 157 release_resource(res); 158 kfree(res); 159 } 160 EXPORT_SYMBOL(atari_stram_free); 161