1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * ioport.c: Simple io mapping allocator. 4 * 5 * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu) 6 * Copyright (C) 1995 Miguel de Icaza (miguel@nuclecu.unam.mx) 7 * 8 * 1996: sparc_free_io, 1999: ioremap()/iounmap() by Pete Zaitcev. 9 * 10 * 2000/01/29 11 * <rth> zait: as long as pci_alloc_consistent produces something addressable, 12 * things are ok. 13 * <zaitcev> rth: no, it is relevant, because get_free_pages returns you a 14 * pointer into the big page mapping 15 * <rth> zait: so what? 16 * <rth> zait: remap_it_my_way(virt_to_phys(get_free_page())) 17 * <zaitcev> Hmm 18 * <zaitcev> Suppose I did this remap_it_my_way(virt_to_phys(get_free_page())). 19 * So far so good. 20 * <zaitcev> Now, driver calls pci_free_consistent(with result of 21 * remap_it_my_way()). 22 * <zaitcev> How do you find the address to pass to free_pages()? 23 * <rth> zait: walk the page tables? It's only two or three level after all. 24 * <rth> zait: you have to walk them anyway to remove the mapping. 25 * <zaitcev> Hmm 26 * <zaitcev> Sounds reasonable 27 */ 28 29 #include <linux/module.h> 30 #include <linux/sched.h> 31 #include <linux/kernel.h> 32 #include <linux/errno.h> 33 #include <linux/types.h> 34 #include <linux/ioport.h> 35 #include <linux/mm.h> 36 #include <linux/slab.h> 37 #include <linux/pci.h> /* struct pci_dev */ 38 #include <linux/proc_fs.h> 39 #include <linux/seq_file.h> 40 #include <linux/scatterlist.h> 41 #include <linux/dma-noncoherent.h> 42 #include <linux/of_device.h> 43 44 #include <asm/io.h> 45 #include <asm/vaddrs.h> 46 #include <asm/oplib.h> 47 #include <asm/prom.h> 48 #include <asm/page.h> 49 #include <asm/pgalloc.h> 50 #include <asm/dma.h> 51 #include <asm/iommu.h> 52 #include <asm/io-unit.h> 53 #include <asm/leon.h> 54 55 /* This function must make sure that caches and memory are coherent after DMA 56 * On LEON systems without cache snooping it flushes the entire D-CACHE. 57 */ 58 static inline void dma_make_coherent(unsigned long pa, unsigned long len) 59 { 60 if (sparc_cpu_model == sparc_leon) { 61 if (!sparc_leon3_snooping_enabled()) 62 leon_flush_dcache_all(); 63 } 64 } 65 66 static void __iomem *_sparc_ioremap(struct resource *res, u32 bus, u32 pa, int sz); 67 static void __iomem *_sparc_alloc_io(unsigned int busno, unsigned long phys, 68 unsigned long size, char *name); 69 static void _sparc_free_io(struct resource *res); 70 71 static void register_proc_sparc_ioport(void); 72 73 /* This points to the next to use virtual memory for DVMA mappings */ 74 static struct resource _sparc_dvma = { 75 .name = "sparc_dvma", .start = DVMA_VADDR, .end = DVMA_END - 1 76 }; 77 /* This points to the start of I/O mappings, cluable from outside. */ 78 /*ext*/ struct resource sparc_iomap = { 79 .name = "sparc_iomap", .start = IOBASE_VADDR, .end = IOBASE_END - 1 80 }; 81 82 /* 83 * Our mini-allocator... 84 * Boy this is gross! We need it because we must map I/O for 85 * timers and interrupt controller before the kmalloc is available. 86 */ 87 88 #define XNMLN 15 89 #define XNRES 10 /* SS-10 uses 8 */ 90 91 struct xresource { 92 struct resource xres; /* Must be first */ 93 int xflag; /* 1 == used */ 94 char xname[XNMLN+1]; 95 }; 96 97 static struct xresource xresv[XNRES]; 98 99 static struct xresource *xres_alloc(void) { 100 struct xresource *xrp; 101 int n; 102 103 xrp = xresv; 104 for (n = 0; n < XNRES; n++) { 105 if (xrp->xflag == 0) { 106 xrp->xflag = 1; 107 return xrp; 108 } 109 xrp++; 110 } 111 return NULL; 112 } 113 114 static void xres_free(struct xresource *xrp) { 115 xrp->xflag = 0; 116 } 117 118 /* 119 * These are typically used in PCI drivers 120 * which are trying to be cross-platform. 121 * 122 * Bus type is always zero on IIep. 123 */ 124 void __iomem *ioremap(phys_addr_t offset, size_t size) 125 { 126 char name[14]; 127 128 sprintf(name, "phys_%08x", (u32)offset); 129 return _sparc_alloc_io(0, (unsigned long)offset, size, name); 130 } 131 EXPORT_SYMBOL(ioremap); 132 133 /* 134 * Complementary to ioremap(). 135 */ 136 void iounmap(volatile void __iomem *virtual) 137 { 138 unsigned long vaddr = (unsigned long) virtual & PAGE_MASK; 139 struct resource *res; 140 141 /* 142 * XXX Too slow. Can have 8192 DVMA pages on sun4m in the worst case. 143 * This probably warrants some sort of hashing. 144 */ 145 if ((res = lookup_resource(&sparc_iomap, vaddr)) == NULL) { 146 printk("free_io/iounmap: cannot free %lx\n", vaddr); 147 return; 148 } 149 _sparc_free_io(res); 150 151 if ((char *)res >= (char*)xresv && (char *)res < (char *)&xresv[XNRES]) { 152 xres_free((struct xresource *)res); 153 } else { 154 kfree(res); 155 } 156 } 157 EXPORT_SYMBOL(iounmap); 158 159 void __iomem *of_ioremap(struct resource *res, unsigned long offset, 160 unsigned long size, char *name) 161 { 162 return _sparc_alloc_io(res->flags & 0xF, 163 res->start + offset, 164 size, name); 165 } 166 EXPORT_SYMBOL(of_ioremap); 167 168 void of_iounmap(struct resource *res, void __iomem *base, unsigned long size) 169 { 170 iounmap(base); 171 } 172 EXPORT_SYMBOL(of_iounmap); 173 174 /* 175 * Meat of mapping 176 */ 177 static void __iomem *_sparc_alloc_io(unsigned int busno, unsigned long phys, 178 unsigned long size, char *name) 179 { 180 static int printed_full; 181 struct xresource *xres; 182 struct resource *res; 183 char *tack; 184 int tlen; 185 void __iomem *va; /* P3 diag */ 186 187 if (name == NULL) name = "???"; 188 189 if ((xres = xres_alloc()) != NULL) { 190 tack = xres->xname; 191 res = &xres->xres; 192 } else { 193 if (!printed_full) { 194 printk("ioremap: done with statics, switching to malloc\n"); 195 printed_full = 1; 196 } 197 tlen = strlen(name); 198 tack = kmalloc(sizeof (struct resource) + tlen + 1, GFP_KERNEL); 199 if (tack == NULL) return NULL; 200 memset(tack, 0, sizeof(struct resource)); 201 res = (struct resource *) tack; 202 tack += sizeof (struct resource); 203 } 204 205 strlcpy(tack, name, XNMLN+1); 206 res->name = tack; 207 208 va = _sparc_ioremap(res, busno, phys, size); 209 /* printk("ioremap(0x%x:%08lx[0x%lx])=%p\n", busno, phys, size, va); */ /* P3 diag */ 210 return va; 211 } 212 213 /* 214 */ 215 static void __iomem * 216 _sparc_ioremap(struct resource *res, u32 bus, u32 pa, int sz) 217 { 218 unsigned long offset = ((unsigned long) pa) & (~PAGE_MASK); 219 220 if (allocate_resource(&sparc_iomap, res, 221 (offset + sz + PAGE_SIZE-1) & PAGE_MASK, 222 sparc_iomap.start, sparc_iomap.end, PAGE_SIZE, NULL, NULL) != 0) { 223 /* Usually we cannot see printks in this case. */ 224 prom_printf("alloc_io_res(%s): cannot occupy\n", 225 (res->name != NULL)? res->name: "???"); 226 prom_halt(); 227 } 228 229 pa &= PAGE_MASK; 230 srmmu_mapiorange(bus, pa, res->start, resource_size(res)); 231 232 return (void __iomem *)(unsigned long)(res->start + offset); 233 } 234 235 /* 236 * Complementary to _sparc_ioremap(). 237 */ 238 static void _sparc_free_io(struct resource *res) 239 { 240 unsigned long plen; 241 242 plen = resource_size(res); 243 BUG_ON((plen & (PAGE_SIZE-1)) != 0); 244 srmmu_unmapiorange(res->start, plen); 245 release_resource(res); 246 } 247 248 unsigned long sparc_dma_alloc_resource(struct device *dev, size_t len) 249 { 250 struct resource *res; 251 252 res = kzalloc(sizeof(*res), GFP_KERNEL); 253 if (!res) 254 return 0; 255 res->name = dev->of_node->full_name; 256 257 if (allocate_resource(&_sparc_dvma, res, len, _sparc_dvma.start, 258 _sparc_dvma.end, PAGE_SIZE, NULL, NULL) != 0) { 259 printk("%s: cannot occupy 0x%zx", __func__, len); 260 kfree(res); 261 return 0; 262 } 263 264 return res->start; 265 } 266 267 bool sparc_dma_free_resource(void *cpu_addr, size_t size) 268 { 269 unsigned long addr = (unsigned long)cpu_addr; 270 struct resource *res; 271 272 res = lookup_resource(&_sparc_dvma, addr); 273 if (!res) { 274 printk("%s: cannot free %p\n", __func__, cpu_addr); 275 return false; 276 } 277 278 if ((addr & (PAGE_SIZE - 1)) != 0) { 279 printk("%s: unaligned va %p\n", __func__, cpu_addr); 280 return false; 281 } 282 283 size = PAGE_ALIGN(size); 284 if (resource_size(res) != size) { 285 printk("%s: region 0x%lx asked 0x%zx\n", 286 __func__, (long)resource_size(res), size); 287 return false; 288 } 289 290 release_resource(res); 291 kfree(res); 292 return true; 293 } 294 295 #ifdef CONFIG_SBUS 296 297 void sbus_set_sbus64(struct device *dev, int x) 298 { 299 printk("sbus_set_sbus64: unsupported\n"); 300 } 301 EXPORT_SYMBOL(sbus_set_sbus64); 302 303 static int __init sparc_register_ioport(void) 304 { 305 register_proc_sparc_ioport(); 306 307 return 0; 308 } 309 310 arch_initcall(sparc_register_ioport); 311 312 #endif /* CONFIG_SBUS */ 313 314 315 /* Allocate and map kernel buffer using consistent mode DMA for a device. 316 * hwdev should be valid struct pci_dev pointer for PCI devices. 317 */ 318 void *arch_dma_alloc(struct device *dev, size_t size, dma_addr_t *dma_handle, 319 gfp_t gfp, unsigned long attrs) 320 { 321 unsigned long addr; 322 void *va; 323 324 if (!size || size > 256 * 1024) /* __get_free_pages() limit */ 325 return NULL; 326 327 size = PAGE_ALIGN(size); 328 va = (void *) __get_free_pages(gfp | __GFP_ZERO, get_order(size)); 329 if (!va) { 330 printk("%s: no %zd pages\n", __func__, size >> PAGE_SHIFT); 331 return NULL; 332 } 333 334 addr = sparc_dma_alloc_resource(dev, size); 335 if (!addr) 336 goto err_nomem; 337 338 srmmu_mapiorange(0, virt_to_phys(va), addr, size); 339 340 *dma_handle = virt_to_phys(va); 341 return (void *)addr; 342 343 err_nomem: 344 free_pages((unsigned long)va, get_order(size)); 345 return NULL; 346 } 347 348 /* Free and unmap a consistent DMA buffer. 349 * cpu_addr is what was returned arch_dma_alloc, size must be the same as what 350 * was passed into arch_dma_alloc, and likewise dma_addr must be the same as 351 * what *dma_ndler was set to. 352 * 353 * References to the memory and mappings associated with cpu_addr/dma_addr 354 * past this call are illegal. 355 */ 356 void arch_dma_free(struct device *dev, size_t size, void *cpu_addr, 357 dma_addr_t dma_addr, unsigned long attrs) 358 { 359 if (!sparc_dma_free_resource(cpu_addr, PAGE_ALIGN(size))) 360 return; 361 362 dma_make_coherent(dma_addr, size); 363 srmmu_unmapiorange((unsigned long)cpu_addr, size); 364 free_pages((unsigned long)phys_to_virt(dma_addr), get_order(size)); 365 } 366 367 /* IIep is write-through, not flushing on cpu to device transfer. */ 368 369 void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size, 370 enum dma_data_direction dir) 371 { 372 if (dir != PCI_DMA_TODEVICE) 373 dma_make_coherent(paddr, PAGE_ALIGN(size)); 374 } 375 376 #ifdef CONFIG_PROC_FS 377 378 static int sparc_io_proc_show(struct seq_file *m, void *v) 379 { 380 struct resource *root = m->private, *r; 381 const char *nm; 382 383 for (r = root->child; r != NULL; r = r->sibling) { 384 if ((nm = r->name) == NULL) nm = "???"; 385 seq_printf(m, "%016llx-%016llx: %s\n", 386 (unsigned long long)r->start, 387 (unsigned long long)r->end, nm); 388 } 389 390 return 0; 391 } 392 #endif /* CONFIG_PROC_FS */ 393 394 static void register_proc_sparc_ioport(void) 395 { 396 #ifdef CONFIG_PROC_FS 397 proc_create_single_data("io_map", 0, NULL, sparc_io_proc_show, 398 &sparc_iomap); 399 proc_create_single_data("dvma_map", 0, NULL, sparc_io_proc_show, 400 &_sparc_dvma); 401 #endif 402 } 403