xref: /openbmc/linux/arch/alpha/kernel/pci-sysfs.c (revision 0a9d991c)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * arch/alpha/kernel/pci-sysfs.c
4  *
5  * Copyright (C) 2009 Ivan Kokshaysky
6  *
7  * Alpha PCI resource files.
8  *
9  * Loosely based on generic HAVE_PCI_MMAP implementation in
10  * drivers/pci/pci-sysfs.c
11  */
12 
13 #include <linux/sched.h>
14 #include <linux/stat.h>
15 #include <linux/slab.h>
16 #include <linux/pci.h>
17 
hose_mmap_page_range(struct pci_controller * hose,struct vm_area_struct * vma,enum pci_mmap_state mmap_type,int sparse)18 static int hose_mmap_page_range(struct pci_controller *hose,
19 				struct vm_area_struct *vma,
20 				enum pci_mmap_state mmap_type, int sparse)
21 {
22 	unsigned long base;
23 
24 	if (mmap_type == pci_mmap_mem)
25 		base = sparse ? hose->sparse_mem_base : hose->dense_mem_base;
26 	else
27 		base = sparse ? hose->sparse_io_base : hose->dense_io_base;
28 
29 	vma->vm_pgoff += base >> PAGE_SHIFT;
30 
31 	return io_remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
32 				  vma->vm_end - vma->vm_start,
33 				  vma->vm_page_prot);
34 }
35 
__pci_mmap_fits(struct pci_dev * pdev,int num,struct vm_area_struct * vma,int sparse)36 static int __pci_mmap_fits(struct pci_dev *pdev, int num,
37 			   struct vm_area_struct *vma, int sparse)
38 {
39 	unsigned long nr, start, size;
40 	int shift = sparse ? 5 : 0;
41 
42 	nr = vma_pages(vma);
43 	start = vma->vm_pgoff;
44 	size = ((pci_resource_len(pdev, num) - 1) >> (PAGE_SHIFT - shift)) + 1;
45 
46 	if (start < size && size - start >= nr)
47 		return 1;
48 	WARN(1, "process \"%s\" tried to map%s 0x%08lx-0x%08lx on %s BAR %d "
49 		"(size 0x%08lx)\n",
50 		current->comm, sparse ? " sparse" : "", start, start + nr,
51 		pci_name(pdev), num, size);
52 	return 0;
53 }
54 
55 /**
56  * pci_mmap_resource - map a PCI resource into user memory space
57  * @kobj: kobject for mapping
58  * @attr: struct bin_attribute for the file being mapped
59  * @vma: struct vm_area_struct passed into the mmap
60  * @sparse: address space type
61  *
62  * Use the bus mapping routines to map a PCI resource into userspace.
63  *
64  * Return: %0 on success, negative error code otherwise
65  */
pci_mmap_resource(struct kobject * kobj,struct bin_attribute * attr,struct vm_area_struct * vma,int sparse)66 static int pci_mmap_resource(struct kobject *kobj,
67 			     struct bin_attribute *attr,
68 			     struct vm_area_struct *vma, int sparse)
69 {
70 	struct pci_dev *pdev = to_pci_dev(kobj_to_dev(kobj));
71 	struct resource *res = attr->private;
72 	enum pci_mmap_state mmap_type;
73 	struct pci_bus_region bar;
74 	int i;
75 
76 	for (i = 0; i < PCI_STD_NUM_BARS; i++)
77 		if (res == &pdev->resource[i])
78 			break;
79 	if (i >= PCI_STD_NUM_BARS)
80 		return -ENODEV;
81 
82 	if (res->flags & IORESOURCE_MEM && iomem_is_exclusive(res->start))
83 		return -EINVAL;
84 
85 	if (!__pci_mmap_fits(pdev, i, vma, sparse))
86 		return -EINVAL;
87 
88 	pcibios_resource_to_bus(pdev->bus, &bar, res);
89 	vma->vm_pgoff += bar.start >> (PAGE_SHIFT - (sparse ? 5 : 0));
90 	mmap_type = res->flags & IORESOURCE_MEM ? pci_mmap_mem : pci_mmap_io;
91 
92 	return hose_mmap_page_range(pdev->sysdata, vma, mmap_type, sparse);
93 }
94 
pci_mmap_resource_sparse(struct file * filp,struct kobject * kobj,struct bin_attribute * attr,struct vm_area_struct * vma)95 static int pci_mmap_resource_sparse(struct file *filp, struct kobject *kobj,
96 				    struct bin_attribute *attr,
97 				    struct vm_area_struct *vma)
98 {
99 	return pci_mmap_resource(kobj, attr, vma, 1);
100 }
101 
pci_mmap_resource_dense(struct file * filp,struct kobject * kobj,struct bin_attribute * attr,struct vm_area_struct * vma)102 static int pci_mmap_resource_dense(struct file *filp, struct kobject *kobj,
103 				   struct bin_attribute *attr,
104 				   struct vm_area_struct *vma)
105 {
106 	return pci_mmap_resource(kobj, attr, vma, 0);
107 }
108 
109 /**
110  * pci_remove_resource_files - cleanup resource files
111  * @pdev: pci_dev to cleanup
112  *
113  * If we created resource files for @dev, remove them from sysfs and
114  * free their resources.
115  */
pci_remove_resource_files(struct pci_dev * pdev)116 void pci_remove_resource_files(struct pci_dev *pdev)
117 {
118 	int i;
119 
120 	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
121 		struct bin_attribute *res_attr;
122 
123 		res_attr = pdev->res_attr[i];
124 		if (res_attr) {
125 			sysfs_remove_bin_file(&pdev->dev.kobj, res_attr);
126 			kfree(res_attr);
127 		}
128 
129 		res_attr = pdev->res_attr_wc[i];
130 		if (res_attr) {
131 			sysfs_remove_bin_file(&pdev->dev.kobj, res_attr);
132 			kfree(res_attr);
133 		}
134 	}
135 }
136 
sparse_mem_mmap_fits(struct pci_dev * pdev,int num)137 static int sparse_mem_mmap_fits(struct pci_dev *pdev, int num)
138 {
139 	struct pci_bus_region bar;
140 	struct pci_controller *hose = pdev->sysdata;
141 	long dense_offset;
142 	unsigned long sparse_size;
143 
144 	pcibios_resource_to_bus(pdev->bus, &bar, &pdev->resource[num]);
145 
146 	/* All core logic chips have 4G sparse address space, except
147 	   CIA which has 16G (see xxx_SPARSE_MEM and xxx_DENSE_MEM
148 	   definitions in asm/core_xxx.h files). This corresponds
149 	   to 128M or 512M of the bus space. */
150 	dense_offset = (long)(hose->dense_mem_base - hose->sparse_mem_base);
151 	sparse_size = dense_offset >= 0x400000000UL ? 0x20000000 : 0x8000000;
152 
153 	return bar.end < sparse_size;
154 }
155 
pci_create_one_attr(struct pci_dev * pdev,int num,char * name,char * suffix,struct bin_attribute * res_attr,unsigned long sparse)156 static int pci_create_one_attr(struct pci_dev *pdev, int num, char *name,
157 			       char *suffix, struct bin_attribute *res_attr,
158 			       unsigned long sparse)
159 {
160 	size_t size = pci_resource_len(pdev, num);
161 
162 	sprintf(name, "resource%d%s", num, suffix);
163 	res_attr->mmap = sparse ? pci_mmap_resource_sparse :
164 				  pci_mmap_resource_dense;
165 	res_attr->attr.name = name;
166 	res_attr->attr.mode = S_IRUSR | S_IWUSR;
167 	res_attr->size = sparse ? size << 5 : size;
168 	res_attr->private = &pdev->resource[num];
169 	return sysfs_create_bin_file(&pdev->dev.kobj, res_attr);
170 }
171 
pci_create_attr(struct pci_dev * pdev,int num)172 static int pci_create_attr(struct pci_dev *pdev, int num)
173 {
174 	/* allocate attribute structure, piggyback attribute name */
175 	int retval, nlen1, nlen2 = 0, res_count = 1;
176 	unsigned long sparse_base, dense_base;
177 	struct bin_attribute *attr;
178 	struct pci_controller *hose = pdev->sysdata;
179 	char *suffix, *attr_name;
180 
181 	suffix = "";	/* Assume bwx machine, normal resourceN files. */
182 	nlen1 = 10;
183 
184 	if (pdev->resource[num].flags & IORESOURCE_MEM) {
185 		sparse_base = hose->sparse_mem_base;
186 		dense_base = hose->dense_mem_base;
187 		if (sparse_base && !sparse_mem_mmap_fits(pdev, num)) {
188 			sparse_base = 0;
189 			suffix = "_dense";
190 			nlen1 = 16;	/* resourceN_dense */
191 		}
192 	} else {
193 		sparse_base = hose->sparse_io_base;
194 		dense_base = hose->dense_io_base;
195 	}
196 
197 	if (sparse_base) {
198 		suffix = "_sparse";
199 		nlen1 = 17;
200 		if (dense_base) {
201 			nlen2 = 16;	/* resourceN_dense */
202 			res_count = 2;
203 		}
204 	}
205 
206 	attr = kzalloc(sizeof(*attr) * res_count + nlen1 + nlen2, GFP_ATOMIC);
207 	if (!attr)
208 		return -ENOMEM;
209 
210 	/* Create bwx, sparse or single dense file */
211 	attr_name = (char *)(attr + res_count);
212 	pdev->res_attr[num] = attr;
213 	retval = pci_create_one_attr(pdev, num, attr_name, suffix, attr,
214 				     sparse_base);
215 	if (retval || res_count == 1)
216 		return retval;
217 
218 	/* Create dense file */
219 	attr_name += nlen1;
220 	attr++;
221 	pdev->res_attr_wc[num] = attr;
222 	return pci_create_one_attr(pdev, num, attr_name, "_dense", attr, 0);
223 }
224 
225 /**
226  * pci_create_resource_files - create resource files in sysfs for @pdev
227  * @pdev: pci_dev in question
228  *
229  * Walk the resources in @dev creating files for each resource available.
230  *
231  * Return: %0 on success, or negative error code
232  */
pci_create_resource_files(struct pci_dev * pdev)233 int pci_create_resource_files(struct pci_dev *pdev)
234 {
235 	int i;
236 	int retval;
237 
238 	/* Expose the PCI resources from this device as files */
239 	for (i = 0; i < PCI_STD_NUM_BARS; i++) {
240 
241 		/* skip empty resources */
242 		if (!pci_resource_len(pdev, i))
243 			continue;
244 
245 		retval = pci_create_attr(pdev, i);
246 		if (retval) {
247 			pci_remove_resource_files(pdev);
248 			return retval;
249 		}
250 	}
251 	return 0;
252 }
253 
254 /* Legacy I/O bus mapping stuff. */
255 
__legacy_mmap_fits(struct pci_controller * hose,struct vm_area_struct * vma,unsigned long res_size,int sparse)256 static int __legacy_mmap_fits(struct pci_controller *hose,
257 			      struct vm_area_struct *vma,
258 			      unsigned long res_size, int sparse)
259 {
260 	unsigned long nr, start, size;
261 
262 	nr = vma_pages(vma);
263 	start = vma->vm_pgoff;
264 	size = ((res_size - 1) >> PAGE_SHIFT) + 1;
265 
266 	if (start < size && size - start >= nr)
267 		return 1;
268 	WARN(1, "process \"%s\" tried to map%s 0x%08lx-0x%08lx on hose %d "
269 		"(size 0x%08lx)\n",
270 		current->comm, sparse ? " sparse" : "", start, start + nr,
271 		hose->index, size);
272 	return 0;
273 }
274 
has_sparse(struct pci_controller * hose,enum pci_mmap_state mmap_type)275 static inline int has_sparse(struct pci_controller *hose,
276 			     enum pci_mmap_state mmap_type)
277 {
278 	unsigned long base;
279 
280 	base = (mmap_type == pci_mmap_mem) ? hose->sparse_mem_base :
281 					     hose->sparse_io_base;
282 
283 	return base != 0;
284 }
285 
pci_mmap_legacy_page_range(struct pci_bus * bus,struct vm_area_struct * vma,enum pci_mmap_state mmap_type)286 int pci_mmap_legacy_page_range(struct pci_bus *bus, struct vm_area_struct *vma,
287 			       enum pci_mmap_state mmap_type)
288 {
289 	struct pci_controller *hose = bus->sysdata;
290 	int sparse = has_sparse(hose, mmap_type);
291 	unsigned long res_size;
292 
293 	res_size = (mmap_type == pci_mmap_mem) ? bus->legacy_mem->size :
294 						 bus->legacy_io->size;
295 	if (!__legacy_mmap_fits(hose, vma, res_size, sparse))
296 		return -EINVAL;
297 
298 	return hose_mmap_page_range(hose, vma, mmap_type, sparse);
299 }
300 
301 /**
302  * pci_adjust_legacy_attr - adjustment of legacy file attributes
303  * @bus: bus to create files under
304  * @mmap_type: I/O port or memory
305  *
306  * Adjust file name and size for sparse mappings.
307  */
pci_adjust_legacy_attr(struct pci_bus * bus,enum pci_mmap_state mmap_type)308 void pci_adjust_legacy_attr(struct pci_bus *bus, enum pci_mmap_state mmap_type)
309 {
310 	struct pci_controller *hose = bus->sysdata;
311 
312 	if (!has_sparse(hose, mmap_type))
313 		return;
314 
315 	if (mmap_type == pci_mmap_mem) {
316 		bus->legacy_mem->attr.name = "legacy_mem_sparse";
317 		bus->legacy_mem->size <<= 5;
318 	} else {
319 		bus->legacy_io->attr.name = "legacy_io_sparse";
320 		bus->legacy_io->size <<= 5;
321 	}
322 	return;
323 }
324 
325 /* Legacy I/O bus read/write functions */
pci_legacy_read(struct pci_bus * bus,loff_t port,u32 * val,size_t size)326 int pci_legacy_read(struct pci_bus *bus, loff_t port, u32 *val, size_t size)
327 {
328 	struct pci_controller *hose = bus->sysdata;
329 
330 	port += hose->io_space->start;
331 
332 	switch(size) {
333 	case 1:
334 		*((u8 *)val) = inb(port);
335 		return 1;
336 	case 2:
337 		if (port & 1)
338 			return -EINVAL;
339 		*((u16 *)val) = inw(port);
340 		return 2;
341 	case 4:
342 		if (port & 3)
343 			return -EINVAL;
344 		*((u32 *)val) = inl(port);
345 		return 4;
346 	}
347 	return -EINVAL;
348 }
349 
pci_legacy_write(struct pci_bus * bus,loff_t port,u32 val,size_t size)350 int pci_legacy_write(struct pci_bus *bus, loff_t port, u32 val, size_t size)
351 {
352 	struct pci_controller *hose = bus->sysdata;
353 
354 	port += hose->io_space->start;
355 
356 	switch(size) {
357 	case 1:
358 		outb(port, val);
359 		return 1;
360 	case 2:
361 		if (port & 1)
362 			return -EINVAL;
363 		outw(port, val);
364 		return 2;
365 	case 4:
366 		if (port & 3)
367 			return -EINVAL;
368 		outl(port, val);
369 		return 4;
370 	}
371 	return -EINVAL;
372 }
373