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/memblock.h> 21 #include <linux/mount.h> 22 #include <linux/blkdev.h> 23 #include <linux/module.h> 24 #include <linux/ioport.h> 25 26 #include <asm/setup.h> 27 #include <asm/machdep.h> 28 #include <asm/page.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 static unsigned long stram_virt_offset; 51 52 static int __init atari_stram_setup(char *arg) 53 { 54 if (!MACH_IS_ATARI) 55 return 0; 56 57 pool_size = memparse(arg, NULL); 58 return 0; 59 } 60 61 early_param("stram_pool", atari_stram_setup); 62 63 64 /* 65 * This init function is called very early by atari/config.c 66 * It initializes some internal variables needed for stram_alloc() 67 */ 68 void __init atari_stram_init(void) 69 { 70 int i; 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 kernel_in_stram = (m68k_memory[0].addr == 0); 77 78 for (i = 0; i < m68k_num_memory; ++i) { 79 if (m68k_memory[i].addr == 0) { 80 return; 81 } 82 } 83 84 /* Should never come here! (There is always ST-Ram!) */ 85 panic("atari_stram_init: no ST-RAM found!"); 86 } 87 88 89 /* 90 * This function is called from setup_arch() to reserve the pages needed for 91 * ST-RAM management, if the kernel resides in ST-RAM. 92 */ 93 void __init atari_stram_reserve_pages(void *start_mem) 94 { 95 if (kernel_in_stram) { 96 pr_debug("atari_stram pool: kernel in ST-RAM, using alloc_bootmem!\n"); 97 stram_pool.start = (resource_size_t)memblock_alloc_low(pool_size, 98 PAGE_SIZE); 99 if (!stram_pool.start) 100 panic("%s: Failed to allocate %lu bytes align=%lx\n", 101 __func__, pool_size, PAGE_SIZE); 102 103 stram_pool.end = stram_pool.start + pool_size - 1; 104 request_resource(&iomem_resource, &stram_pool); 105 stram_virt_offset = 0; 106 pr_debug("atari_stram pool: size = %lu bytes, resource = %pR\n", 107 pool_size, &stram_pool); 108 pr_debug("atari_stram pool: stram_virt_offset = %lx\n", 109 stram_virt_offset); 110 } 111 } 112 113 114 /* 115 * This function is called as arch initcall to reserve the pages needed for 116 * ST-RAM management, if the kernel does not reside in ST-RAM. 117 */ 118 int __init atari_stram_map_pages(void) 119 { 120 if (!kernel_in_stram) { 121 /* 122 * Skip page 0, as the fhe first 2 KiB are supervisor-only! 123 */ 124 pr_debug("atari_stram pool: kernel not in ST-RAM, using ioremap!\n"); 125 stram_pool.start = PAGE_SIZE; 126 stram_pool.end = stram_pool.start + pool_size - 1; 127 request_resource(&iomem_resource, &stram_pool); 128 stram_virt_offset = (unsigned long) ioremap(stram_pool.start, 129 resource_size(&stram_pool)) - stram_pool.start; 130 pr_debug("atari_stram pool: size = %lu bytes, resource = %pR\n", 131 pool_size, &stram_pool); 132 pr_debug("atari_stram pool: stram_virt_offset = %lx\n", 133 stram_virt_offset); 134 } 135 return 0; 136 } 137 arch_initcall(atari_stram_map_pages); 138 139 140 void *atari_stram_to_virt(unsigned long phys) 141 { 142 return (void *)(phys + stram_virt_offset); 143 } 144 EXPORT_SYMBOL(atari_stram_to_virt); 145 146 147 unsigned long atari_stram_to_phys(void *virt) 148 { 149 return (unsigned long)(virt - stram_virt_offset); 150 } 151 EXPORT_SYMBOL(atari_stram_to_phys); 152 153 154 void *atari_stram_alloc(unsigned long size, const char *owner) 155 { 156 struct resource *res; 157 int error; 158 159 pr_debug("atari_stram_alloc: allocate %lu bytes\n", size); 160 161 /* round up */ 162 size = PAGE_ALIGN(size); 163 164 res = kzalloc(sizeof(struct resource), GFP_KERNEL); 165 if (!res) 166 return NULL; 167 168 res->name = owner; 169 error = allocate_resource(&stram_pool, res, size, 0, UINT_MAX, 170 PAGE_SIZE, NULL, NULL); 171 if (error < 0) { 172 pr_err("atari_stram_alloc: allocate_resource() failed %d!\n", 173 error); 174 kfree(res); 175 return NULL; 176 } 177 178 pr_debug("atari_stram_alloc: returning %pR\n", res); 179 return atari_stram_to_virt(res->start); 180 } 181 EXPORT_SYMBOL(atari_stram_alloc); 182 183 184 void atari_stram_free(void *addr) 185 { 186 unsigned long start = atari_stram_to_phys(addr); 187 struct resource *res; 188 unsigned long size; 189 190 res = lookup_resource(&stram_pool, start); 191 if (!res) { 192 pr_err("atari_stram_free: trying to free nonexistent region " 193 "at %p\n", addr); 194 return; 195 } 196 197 size = resource_size(res); 198 pr_debug("atari_stram_free: free %lu bytes at %p\n", size, addr); 199 release_resource(res); 200 kfree(res); 201 } 202 EXPORT_SYMBOL(atari_stram_free); 203