xref: /openbmc/linux/drivers/pci/of_property.c (revision 49c23519)
1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2022-2023, Advanced Micro Devices, Inc.
4  */
5 
6 #include <linux/pci.h>
7 #include <linux/of.h>
8 #include <linux/of_irq.h>
9 #include <linux/bitfield.h>
10 #include <linux/bits.h>
11 #include "pci.h"
12 
13 #define OF_PCI_ADDRESS_CELLS		3
14 #define OF_PCI_SIZE_CELLS		2
15 #define OF_PCI_MAX_INT_PIN		4
16 
17 struct of_pci_addr_pair {
18 	u32		phys_addr[OF_PCI_ADDRESS_CELLS];
19 	u32		size[OF_PCI_SIZE_CELLS];
20 };
21 
22 /*
23  * Each entry in the ranges table is a tuple containing the child address,
24  * the parent address, and the size of the region in the child address space.
25  * Thus, for PCI, in each entry parent address is an address on the primary
26  * side and the child address is the corresponding address on the secondary
27  * side.
28  */
29 struct of_pci_range {
30 	u32		child_addr[OF_PCI_ADDRESS_CELLS];
31 	u32		parent_addr[OF_PCI_ADDRESS_CELLS];
32 	u32		size[OF_PCI_SIZE_CELLS];
33 };
34 
35 #define OF_PCI_ADDR_SPACE_IO		0x1
36 #define OF_PCI_ADDR_SPACE_MEM32		0x2
37 #define OF_PCI_ADDR_SPACE_MEM64		0x3
38 
39 #define OF_PCI_ADDR_FIELD_NONRELOC	BIT(31)
40 #define OF_PCI_ADDR_FIELD_SS		GENMASK(25, 24)
41 #define OF_PCI_ADDR_FIELD_PREFETCH	BIT(30)
42 #define OF_PCI_ADDR_FIELD_BUS		GENMASK(23, 16)
43 #define OF_PCI_ADDR_FIELD_DEV		GENMASK(15, 11)
44 #define OF_PCI_ADDR_FIELD_FUNC		GENMASK(10, 8)
45 #define OF_PCI_ADDR_FIELD_REG		GENMASK(7, 0)
46 
47 enum of_pci_prop_compatible {
48 	PROP_COMPAT_PCI_VVVV_DDDD,
49 	PROP_COMPAT_PCICLASS_CCSSPP,
50 	PROP_COMPAT_PCICLASS_CCSS,
51 	PROP_COMPAT_NUM,
52 };
53 
54 static void of_pci_set_address(struct pci_dev *pdev, u32 *prop, u64 addr,
55 			       u32 reg_num, u32 flags, bool reloc)
56 {
57 	prop[0] = FIELD_PREP(OF_PCI_ADDR_FIELD_BUS, pdev->bus->number) |
58 		FIELD_PREP(OF_PCI_ADDR_FIELD_DEV, PCI_SLOT(pdev->devfn)) |
59 		FIELD_PREP(OF_PCI_ADDR_FIELD_FUNC, PCI_FUNC(pdev->devfn));
60 	prop[0] |= flags | reg_num;
61 	if (!reloc) {
62 		prop[0] |= OF_PCI_ADDR_FIELD_NONRELOC;
63 		prop[1] = upper_32_bits(addr);
64 		prop[2] = lower_32_bits(addr);
65 	}
66 }
67 
68 static int of_pci_get_addr_flags(struct resource *res, u32 *flags)
69 {
70 	u32 ss;
71 
72 	if (res->flags & IORESOURCE_IO)
73 		ss = OF_PCI_ADDR_SPACE_IO;
74 	else if (res->flags & IORESOURCE_MEM_64)
75 		ss = OF_PCI_ADDR_SPACE_MEM64;
76 	else if (res->flags & IORESOURCE_MEM)
77 		ss = OF_PCI_ADDR_SPACE_MEM32;
78 	else
79 		return -EINVAL;
80 
81 	*flags = 0;
82 	if (res->flags & IORESOURCE_PREFETCH)
83 		*flags |= OF_PCI_ADDR_FIELD_PREFETCH;
84 
85 	*flags |= FIELD_PREP(OF_PCI_ADDR_FIELD_SS, ss);
86 
87 	return 0;
88 }
89 
90 static int of_pci_prop_bus_range(struct pci_dev *pdev,
91 				 struct of_changeset *ocs,
92 				 struct device_node *np)
93 {
94 	u32 bus_range[] = { pdev->subordinate->busn_res.start,
95 			    pdev->subordinate->busn_res.end };
96 
97 	return of_changeset_add_prop_u32_array(ocs, np, "bus-range", bus_range,
98 					       ARRAY_SIZE(bus_range));
99 }
100 
101 static int of_pci_prop_ranges(struct pci_dev *pdev, struct of_changeset *ocs,
102 			      struct device_node *np)
103 {
104 	struct of_pci_range *rp;
105 	struct resource *res;
106 	int i, j, ret;
107 	u32 flags, num;
108 	u64 val64;
109 
110 	if (pci_is_bridge(pdev)) {
111 		num = PCI_BRIDGE_RESOURCE_NUM;
112 		res = &pdev->resource[PCI_BRIDGE_RESOURCES];
113 	} else {
114 		num = PCI_STD_NUM_BARS;
115 		res = &pdev->resource[PCI_STD_RESOURCES];
116 	}
117 
118 	rp = kcalloc(num, sizeof(*rp), GFP_KERNEL);
119 	if (!rp)
120 		return -ENOMEM;
121 
122 	for (i = 0, j = 0; j < num; j++) {
123 		if (!resource_size(&res[j]))
124 			continue;
125 
126 		if (of_pci_get_addr_flags(&res[j], &flags))
127 			continue;
128 
129 		val64 = res[j].start;
130 		of_pci_set_address(pdev, rp[i].parent_addr, val64, 0, flags,
131 				   false);
132 		if (pci_is_bridge(pdev)) {
133 			memcpy(rp[i].child_addr, rp[i].parent_addr,
134 			       sizeof(rp[i].child_addr));
135 		} else {
136 			/*
137 			 * For endpoint device, the lower 64-bits of child
138 			 * address is always zero.
139 			 */
140 			rp[i].child_addr[0] = j;
141 		}
142 
143 		val64 = resource_size(&res[j]);
144 		rp[i].size[0] = upper_32_bits(val64);
145 		rp[i].size[1] = lower_32_bits(val64);
146 
147 		i++;
148 	}
149 
150 	ret = of_changeset_add_prop_u32_array(ocs, np, "ranges", (u32 *)rp,
151 					      i * sizeof(*rp) / sizeof(u32));
152 	kfree(rp);
153 
154 	return ret;
155 }
156 
157 static int of_pci_prop_reg(struct pci_dev *pdev, struct of_changeset *ocs,
158 			   struct device_node *np)
159 {
160 	struct of_pci_addr_pair reg = { 0 };
161 
162 	/* configuration space */
163 	of_pci_set_address(pdev, reg.phys_addr, 0, 0, 0, true);
164 
165 	return of_changeset_add_prop_u32_array(ocs, np, "reg", (u32 *)&reg,
166 					       sizeof(reg) / sizeof(u32));
167 }
168 
169 static int of_pci_prop_interrupts(struct pci_dev *pdev,
170 				  struct of_changeset *ocs,
171 				  struct device_node *np)
172 {
173 	int ret;
174 	u8 pin;
175 
176 	ret = pci_read_config_byte(pdev, PCI_INTERRUPT_PIN, &pin);
177 	if (ret != 0)
178 		return ret;
179 
180 	if (!pin)
181 		return 0;
182 
183 	return of_changeset_add_prop_u32(ocs, np, "interrupts", (u32)pin);
184 }
185 
186 static int of_pci_prop_intr_map(struct pci_dev *pdev, struct of_changeset *ocs,
187 				struct device_node *np)
188 {
189 	u32 i, addr_sz[OF_PCI_MAX_INT_PIN] = { 0 }, map_sz = 0;
190 	struct of_phandle_args out_irq[OF_PCI_MAX_INT_PIN];
191 	__be32 laddr[OF_PCI_ADDRESS_CELLS] = { 0 };
192 	u32 int_map_mask[] = { 0xffff00, 0, 0, 7 };
193 	struct device_node *pnode;
194 	struct pci_dev *child;
195 	u32 *int_map, *mapp;
196 	int ret;
197 	u8 pin;
198 
199 	pnode = pci_device_to_OF_node(pdev->bus->self);
200 	if (!pnode)
201 		pnode = pci_bus_to_OF_node(pdev->bus);
202 
203 	if (!pnode) {
204 		pci_err(pdev, "failed to get parent device node");
205 		return -EINVAL;
206 	}
207 
208 	laddr[0] = cpu_to_be32((pdev->bus->number << 16) | (pdev->devfn << 8));
209 	for (pin = 1; pin <= OF_PCI_MAX_INT_PIN;  pin++) {
210 		i = pin - 1;
211 		out_irq[i].np = pnode;
212 		out_irq[i].args_count = 1;
213 		out_irq[i].args[0] = pin;
214 		ret = of_irq_parse_raw(laddr, &out_irq[i]);
215 		if (ret) {
216 			out_irq[i].np = NULL;
217 			pci_dbg(pdev, "parse irq %d failed, ret %d", pin, ret);
218 			continue;
219 		}
220 		of_property_read_u32(out_irq[i].np, "#address-cells",
221 				     &addr_sz[i]);
222 	}
223 
224 	list_for_each_entry(child, &pdev->subordinate->devices, bus_list) {
225 		for (pin = 1; pin <= OF_PCI_MAX_INT_PIN; pin++) {
226 			i = pci_swizzle_interrupt_pin(child, pin) - 1;
227 			if (!out_irq[i].np)
228 				continue;
229 			map_sz += 5 + addr_sz[i] + out_irq[i].args_count;
230 		}
231 	}
232 
233 	/*
234 	 * Parsing interrupt failed for all pins. In this case, it does not
235 	 * need to generate interrupt-map property.
236 	 */
237 	if (!map_sz)
238 		return 0;
239 
240 	int_map = kcalloc(map_sz, sizeof(u32), GFP_KERNEL);
241 	if (!int_map)
242 		return -ENOMEM;
243 	mapp = int_map;
244 
245 	list_for_each_entry(child, &pdev->subordinate->devices, bus_list) {
246 		for (pin = 1; pin <= OF_PCI_MAX_INT_PIN; pin++) {
247 			i = pci_swizzle_interrupt_pin(child, pin) - 1;
248 			if (!out_irq[i].np)
249 				continue;
250 
251 			*mapp = (child->bus->number << 16) |
252 				(child->devfn << 8);
253 			mapp += OF_PCI_ADDRESS_CELLS;
254 			*mapp = pin;
255 			mapp++;
256 			*mapp = out_irq[i].np->phandle;
257 			mapp++;
258 			if (addr_sz[i]) {
259 				ret = of_property_read_u32_array(out_irq[i].np,
260 								 "reg", mapp,
261 								 addr_sz[i]);
262 				if (ret)
263 					goto failed;
264 			}
265 			mapp += addr_sz[i];
266 			memcpy(mapp, out_irq[i].args,
267 			       out_irq[i].args_count * sizeof(u32));
268 			mapp += out_irq[i].args_count;
269 		}
270 	}
271 
272 	ret = of_changeset_add_prop_u32_array(ocs, np, "interrupt-map", int_map,
273 					      map_sz);
274 	if (ret)
275 		goto failed;
276 
277 	ret = of_changeset_add_prop_u32(ocs, np, "#interrupt-cells", 1);
278 	if (ret)
279 		goto failed;
280 
281 	ret = of_changeset_add_prop_u32_array(ocs, np, "interrupt-map-mask",
282 					      int_map_mask,
283 					      ARRAY_SIZE(int_map_mask));
284 	if (ret)
285 		goto failed;
286 
287 	kfree(int_map);
288 	return 0;
289 
290 failed:
291 	kfree(int_map);
292 	return ret;
293 }
294 
295 static int of_pci_prop_compatible(struct pci_dev *pdev,
296 				  struct of_changeset *ocs,
297 				  struct device_node *np)
298 {
299 	const char *compat_strs[PROP_COMPAT_NUM] = { 0 };
300 	int i, ret;
301 
302 	compat_strs[PROP_COMPAT_PCI_VVVV_DDDD] =
303 		kasprintf(GFP_KERNEL, "pci%x,%x", pdev->vendor, pdev->device);
304 	compat_strs[PROP_COMPAT_PCICLASS_CCSSPP] =
305 		kasprintf(GFP_KERNEL, "pciclass,%06x", pdev->class);
306 	compat_strs[PROP_COMPAT_PCICLASS_CCSS] =
307 		kasprintf(GFP_KERNEL, "pciclass,%04x", pdev->class >> 8);
308 
309 	ret = of_changeset_add_prop_string_array(ocs, np, "compatible",
310 						 compat_strs, PROP_COMPAT_NUM);
311 	for (i = 0; i < PROP_COMPAT_NUM; i++)
312 		kfree(compat_strs[i]);
313 
314 	return ret;
315 }
316 
317 int of_pci_add_properties(struct pci_dev *pdev, struct of_changeset *ocs,
318 			  struct device_node *np)
319 {
320 	int ret;
321 
322 	/*
323 	 * The added properties will be released when the
324 	 * changeset is destroyed.
325 	 */
326 	if (pci_is_bridge(pdev)) {
327 		ret = of_changeset_add_prop_string(ocs, np, "device_type",
328 						   "pci");
329 		if (ret)
330 			return ret;
331 
332 		ret = of_pci_prop_bus_range(pdev, ocs, np);
333 		if (ret)
334 			return ret;
335 
336 		ret = of_pci_prop_intr_map(pdev, ocs, np);
337 		if (ret)
338 			return ret;
339 	}
340 
341 	ret = of_pci_prop_ranges(pdev, ocs, np);
342 	if (ret)
343 		return ret;
344 
345 	ret = of_changeset_add_prop_u32(ocs, np, "#address-cells",
346 					OF_PCI_ADDRESS_CELLS);
347 	if (ret)
348 		return ret;
349 
350 	ret = of_changeset_add_prop_u32(ocs, np, "#size-cells",
351 					OF_PCI_SIZE_CELLS);
352 	if (ret)
353 		return ret;
354 
355 	ret = of_pci_prop_reg(pdev, ocs, np);
356 	if (ret)
357 		return ret;
358 
359 	ret = of_pci_prop_compatible(pdev, ocs, np);
360 	if (ret)
361 		return ret;
362 
363 	ret = of_pci_prop_interrupts(pdev, ocs, np);
364 	if (ret)
365 		return ret;
366 
367 	return 0;
368 }
369