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
18static 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
36static 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 */
66static 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
95static 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
102static 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 */
116void 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
137static 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
156static 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
172static 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 */
233int 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
256static 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
275static 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
286int 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 */
308void 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 */
326int 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
350int 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