xref: /openbmc/linux/arch/alpha/kernel/pci-sysfs.c (revision 94cdda6b)
1 /*
2  * arch/alpha/kernel/pci-sysfs.c
3  *
4  * Copyright (C) 2009 Ivan Kokshaysky
5  *
6  * Alpha PCI resource files.
7  *
8  * Loosely based on generic HAVE_PCI_MMAP implementation in
9  * drivers/pci/pci-sysfs.c
10  */
11 
12 #include <linux/sched.h>
13 #include <linux/stat.h>
14 #include <linux/slab.h>
15 #include <linux/pci.h>
16 
17 static int hose_mmap_page_range(struct pci_controller *hose,
18 				struct vm_area_struct *vma,
19 				enum pci_mmap_state mmap_type, int sparse)
20 {
21 	unsigned long base;
22 
23 	if (mmap_type == pci_mmap_mem)
24 		base = sparse ? hose->sparse_mem_base : hose->dense_mem_base;
25 	else
26 		base = sparse ? hose->sparse_io_base : hose->dense_io_base;
27 
28 	vma->vm_pgoff += base >> PAGE_SHIFT;
29 
30 	return io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
31 				  vma->vm_end - vma->vm_start,
32 				  vma->vm_page_prot);
33 }
34 
35 static int __pci_mmap_fits(struct pci_dev *pdev, int num,
36 			   struct vm_area_struct *vma, int sparse)
37 {
38 	unsigned long nr, start, size;
39 	int shift = sparse ? 5 : 0;
40 
41 	nr = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
42 	start = vma->vm_pgoff;
43 	size = ((pci_resource_len(pdev, num) - 1) >> (PAGE_SHIFT - shift)) + 1;
44 
45 	if (start < size && size - start >= nr)
46 		return 1;
47 	WARN(1, "process \"%s\" tried to map%s 0x%08lx-0x%08lx on %s BAR %d "
48 		"(size 0x%08lx)\n",
49 		current->comm, sparse ? " sparse" : "", start, start + nr,
50 		pci_name(pdev), num, size);
51 	return 0;
52 }
53 
54 /**
55  * pci_mmap_resource - map a PCI resource into user memory space
56  * @kobj: kobject for mapping
57  * @attr: struct bin_attribute for the file being mapped
58  * @vma: struct vm_area_struct passed into the mmap
59  * @sparse: address space type
60  *
61  * Use the bus mapping routines to map a PCI resource into userspace.
62  */
63 static int pci_mmap_resource(struct kobject *kobj,
64 			     struct bin_attribute *attr,
65 			     struct vm_area_struct *vma, int sparse)
66 {
67 	struct pci_dev *pdev = to_pci_dev(container_of(kobj,
68 						       struct device, kobj));
69 	struct resource *res = attr->private;
70 	enum pci_mmap_state mmap_type;
71 	struct pci_bus_region bar;
72 	int i;
73 
74 	for (i = 0; i < PCI_ROM_RESOURCE; i++)
75 		if (res == &pdev->resource[i])
76 			break;
77 	if (i >= PCI_ROM_RESOURCE)
78 		return -ENODEV;
79 
80 	if (!__pci_mmap_fits(pdev, i, vma, sparse))
81 		return -EINVAL;
82 
83 	if (iomem_is_exclusive(res->start))
84 		return -EINVAL;
85 
86 	pcibios_resource_to_bus(pdev->bus, &bar, res);
87 	vma->vm_pgoff += bar.start >> (PAGE_SHIFT - (sparse ? 5 : 0));
88 	mmap_type = res->flags & IORESOURCE_MEM ? pci_mmap_mem : pci_mmap_io;
89 
90 	return hose_mmap_page_range(pdev->sysdata, vma, mmap_type, sparse);
91 }
92 
93 static int pci_mmap_resource_sparse(struct file *filp, struct kobject *kobj,
94 				    struct bin_attribute *attr,
95 				    struct vm_area_struct *vma)
96 {
97 	return pci_mmap_resource(kobj, attr, vma, 1);
98 }
99 
100 static int pci_mmap_resource_dense(struct file *filp, struct kobject *kobj,
101 				   struct bin_attribute *attr,
102 				   struct vm_area_struct *vma)
103 {
104 	return pci_mmap_resource(kobj, attr, vma, 0);
105 }
106 
107 /**
108  * pci_remove_resource_files - cleanup resource files
109  * @dev: dev to cleanup
110  *
111  * If we created resource files for @dev, remove them from sysfs and
112  * free their resources.
113  */
114 void pci_remove_resource_files(struct pci_dev *pdev)
115 {
116 	int i;
117 
118 	for (i = 0; i < PCI_ROM_RESOURCE; i++) {
119 		struct bin_attribute *res_attr;
120 
121 		res_attr = pdev->res_attr[i];
122 		if (res_attr) {
123 			sysfs_remove_bin_file(&pdev->dev.kobj, res_attr);
124 			kfree(res_attr);
125 		}
126 
127 		res_attr = pdev->res_attr_wc[i];
128 		if (res_attr) {
129 			sysfs_remove_bin_file(&pdev->dev.kobj, res_attr);
130 			kfree(res_attr);
131 		}
132 	}
133 }
134 
135 static int sparse_mem_mmap_fits(struct pci_dev *pdev, int num)
136 {
137 	struct pci_bus_region bar;
138 	struct pci_controller *hose = pdev->sysdata;
139 	long dense_offset;
140 	unsigned long sparse_size;
141 
142 	pcibios_resource_to_bus(pdev->bus, &bar, &pdev->resource[num]);
143 
144 	/* All core logic chips have 4G sparse address space, except
145 	   CIA which has 16G (see xxx_SPARSE_MEM and xxx_DENSE_MEM
146 	   definitions in asm/core_xxx.h files). This corresponds
147 	   to 128M or 512M of the bus space. */
148 	dense_offset = (long)(hose->dense_mem_base - hose->sparse_mem_base);
149 	sparse_size = dense_offset >= 0x400000000UL ? 0x20000000 : 0x8000000;
150 
151 	return bar.end < sparse_size;
152 }
153 
154 static int pci_create_one_attr(struct pci_dev *pdev, int num, char *name,
155 			       char *suffix, struct bin_attribute *res_attr,
156 			       unsigned long sparse)
157 {
158 	size_t size = pci_resource_len(pdev, num);
159 
160 	sprintf(name, "resource%d%s", num, suffix);
161 	res_attr->mmap = sparse ? pci_mmap_resource_sparse :
162 				  pci_mmap_resource_dense;
163 	res_attr->attr.name = name;
164 	res_attr->attr.mode = S_IRUSR | S_IWUSR;
165 	res_attr->size = sparse ? size << 5 : size;
166 	res_attr->private = &pdev->resource[num];
167 	return sysfs_create_bin_file(&pdev->dev.kobj, res_attr);
168 }
169 
170 static int pci_create_attr(struct pci_dev *pdev, int num)
171 {
172 	/* allocate attribute structure, piggyback attribute name */
173 	int retval, nlen1, nlen2 = 0, res_count = 1;
174 	unsigned long sparse_base, dense_base;
175 	struct bin_attribute *attr;
176 	struct pci_controller *hose = pdev->sysdata;
177 	char *suffix, *attr_name;
178 
179 	suffix = "";	/* Assume bwx machine, normal resourceN files. */
180 	nlen1 = 10;
181 
182 	if (pdev->resource[num].flags & IORESOURCE_MEM) {
183 		sparse_base = hose->sparse_mem_base;
184 		dense_base = hose->dense_mem_base;
185 		if (sparse_base && !sparse_mem_mmap_fits(pdev, num)) {
186 			sparse_base = 0;
187 			suffix = "_dense";
188 			nlen1 = 16;	/* resourceN_dense */
189 		}
190 	} else {
191 		sparse_base = hose->sparse_io_base;
192 		dense_base = hose->dense_io_base;
193 	}
194 
195 	if (sparse_base) {
196 		suffix = "_sparse";
197 		nlen1 = 17;
198 		if (dense_base) {
199 			nlen2 = 16;	/* resourceN_dense */
200 			res_count = 2;
201 		}
202 	}
203 
204 	attr = kzalloc(sizeof(*attr) * res_count + nlen1 + nlen2, GFP_ATOMIC);
205 	if (!attr)
206 		return -ENOMEM;
207 
208 	/* Create bwx, sparse or single dense file */
209 	attr_name = (char *)(attr + res_count);
210 	pdev->res_attr[num] = attr;
211 	retval = pci_create_one_attr(pdev, num, attr_name, suffix, attr,
212 				     sparse_base);
213 	if (retval || res_count == 1)
214 		return retval;
215 
216 	/* Create dense file */
217 	attr_name += nlen1;
218 	attr++;
219 	pdev->res_attr_wc[num] = attr;
220 	return pci_create_one_attr(pdev, num, attr_name, "_dense", attr, 0);
221 }
222 
223 /**
224  * pci_create_resource_files - create resource files in sysfs for @dev
225  * @dev: dev in question
226  *
227  * Walk the resources in @dev creating files for each resource available.
228  */
229 int pci_create_resource_files(struct pci_dev *pdev)
230 {
231 	int i;
232 	int retval;
233 
234 	/* Expose the PCI resources from this device as files */
235 	for (i = 0; i < PCI_ROM_RESOURCE; i++) {
236 
237 		/* skip empty resources */
238 		if (!pci_resource_len(pdev, i))
239 			continue;
240 
241 		retval = pci_create_attr(pdev, i);
242 		if (retval) {
243 			pci_remove_resource_files(pdev);
244 			return retval;
245 		}
246 	}
247 	return 0;
248 }
249 
250 /* Legacy I/O bus mapping stuff. */
251 
252 static int __legacy_mmap_fits(struct pci_controller *hose,
253 			      struct vm_area_struct *vma,
254 			      unsigned long res_size, int sparse)
255 {
256 	unsigned long nr, start, size;
257 
258 	nr = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
259 	start = vma->vm_pgoff;
260 	size = ((res_size - 1) >> PAGE_SHIFT) + 1;
261 
262 	if (start < size && size - start >= nr)
263 		return 1;
264 	WARN(1, "process \"%s\" tried to map%s 0x%08lx-0x%08lx on hose %d "
265 		"(size 0x%08lx)\n",
266 		current->comm, sparse ? " sparse" : "", start, start + nr,
267 		hose->index, size);
268 	return 0;
269 }
270 
271 static inline int has_sparse(struct pci_controller *hose,
272 			     enum pci_mmap_state mmap_type)
273 {
274 	unsigned long base;
275 
276 	base = (mmap_type == pci_mmap_mem) ? hose->sparse_mem_base :
277 					     hose->sparse_io_base;
278 
279 	return base != 0;
280 }
281 
282 int pci_mmap_legacy_page_range(struct pci_bus *bus, struct vm_area_struct *vma,
283 			       enum pci_mmap_state mmap_type)
284 {
285 	struct pci_controller *hose = bus->sysdata;
286 	int sparse = has_sparse(hose, mmap_type);
287 	unsigned long res_size;
288 
289 	res_size = (mmap_type == pci_mmap_mem) ? bus->legacy_mem->size :
290 						 bus->legacy_io->size;
291 	if (!__legacy_mmap_fits(hose, vma, res_size, sparse))
292 		return -EINVAL;
293 
294 	return hose_mmap_page_range(hose, vma, mmap_type, sparse);
295 }
296 
297 /**
298  * pci_adjust_legacy_attr - adjustment of legacy file attributes
299  * @b: bus to create files under
300  * @mmap_type: I/O port or memory
301  *
302  * Adjust file name and size for sparse mappings.
303  */
304 void pci_adjust_legacy_attr(struct pci_bus *bus, enum pci_mmap_state mmap_type)
305 {
306 	struct pci_controller *hose = bus->sysdata;
307 
308 	if (!has_sparse(hose, mmap_type))
309 		return;
310 
311 	if (mmap_type == pci_mmap_mem) {
312 		bus->legacy_mem->attr.name = "legacy_mem_sparse";
313 		bus->legacy_mem->size <<= 5;
314 	} else {
315 		bus->legacy_io->attr.name = "legacy_io_sparse";
316 		bus->legacy_io->size <<= 5;
317 	}
318 	return;
319 }
320 
321 /* Legacy I/O bus read/write functions */
322 int pci_legacy_read(struct pci_bus *bus, loff_t port, u32 *val, size_t size)
323 {
324 	struct pci_controller *hose = bus->sysdata;
325 
326 	port += hose->io_space->start;
327 
328 	switch(size) {
329 	case 1:
330 		*((u8 *)val) = inb(port);
331 		return 1;
332 	case 2:
333 		if (port & 1)
334 			return -EINVAL;
335 		*((u16 *)val) = inw(port);
336 		return 2;
337 	case 4:
338 		if (port & 3)
339 			return -EINVAL;
340 		*((u32 *)val) = inl(port);
341 		return 4;
342 	}
343 	return -EINVAL;
344 }
345 
346 int pci_legacy_write(struct pci_bus *bus, loff_t port, u32 val, size_t size)
347 {
348 	struct pci_controller *hose = bus->sysdata;
349 
350 	port += hose->io_space->start;
351 
352 	switch(size) {
353 	case 1:
354 		outb(port, val);
355 		return 1;
356 	case 2:
357 		if (port & 1)
358 			return -EINVAL;
359 		outw(port, val);
360 		return 2;
361 	case 4:
362 		if (port & 3)
363 			return -EINVAL;
364 		outl(port, val);
365 		return 4;
366 	}
367 	return -EINVAL;
368 }
369