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-map-ops.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 */
dma_make_coherent(unsigned long pa,unsigned long len)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
xres_alloc(void)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
xres_free(struct xresource * xrp)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 */
ioremap(phys_addr_t offset,size_t size)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 */
iounmap(volatile void __iomem * virtual)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
of_ioremap(struct resource * res,unsigned long offset,unsigned long size,char * name)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
of_iounmap(struct resource * res,void __iomem * base,unsigned long size)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 */
_sparc_alloc_io(unsigned int busno,unsigned long phys,unsigned long size,char * name)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 *
_sparc_ioremap(struct resource * res,u32 bus,u32 pa,int sz)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 */
_sparc_free_io(struct resource * res)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
sparc_dma_alloc_resource(struct device * dev,size_t len)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
sparc_dma_free_resource(void * cpu_addr,size_t size)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
sbus_set_sbus64(struct device * dev,int x)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
sparc_register_ioport(void)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 */
arch_dma_alloc(struct device * dev,size_t size,dma_addr_t * dma_handle,gfp_t gfp,unsigned long attrs)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 */
arch_dma_free(struct device * dev,size_t size,void * cpu_addr,dma_addr_t dma_addr,unsigned long attrs)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 size = PAGE_ALIGN(size);
360
361 if (!sparc_dma_free_resource(cpu_addr, size))
362 return;
363
364 dma_make_coherent(dma_addr, size);
365 srmmu_unmapiorange((unsigned long)cpu_addr, size);
366 free_pages((unsigned long)phys_to_virt(dma_addr), get_order(size));
367 }
368
369 /* IIep is write-through, not flushing on cpu to device transfer. */
370
arch_sync_dma_for_cpu(phys_addr_t paddr,size_t size,enum dma_data_direction dir)371 void arch_sync_dma_for_cpu(phys_addr_t paddr, size_t size,
372 enum dma_data_direction dir)
373 {
374 if (dir != PCI_DMA_TODEVICE)
375 dma_make_coherent(paddr, PAGE_ALIGN(size));
376 }
377
378 #ifdef CONFIG_PROC_FS
379
sparc_io_proc_show(struct seq_file * m,void * v)380 static int sparc_io_proc_show(struct seq_file *m, void *v)
381 {
382 struct resource *root = m->private, *r;
383 const char *nm;
384
385 for (r = root->child; r != NULL; r = r->sibling) {
386 if ((nm = r->name) == NULL) nm = "???";
387 seq_printf(m, "%016llx-%016llx: %s\n",
388 (unsigned long long)r->start,
389 (unsigned long long)r->end, nm);
390 }
391
392 return 0;
393 }
394 #endif /* CONFIG_PROC_FS */
395
register_proc_sparc_ioport(void)396 static void register_proc_sparc_ioport(void)
397 {
398 #ifdef CONFIG_PROC_FS
399 proc_create_single_data("io_map", 0, NULL, sparc_io_proc_show,
400 &sparc_iomap);
401 proc_create_single_data("dvma_map", 0, NULL, sparc_io_proc_show,
402 &_sparc_dvma);
403 #endif
404 }
405