xref: /kvm-unit-tests/lib/pci.c (revision 92d2c192ff927d9c121fa8006000ebcb1f9ad2d5)
1 /*
2  * Copyright (C) 2013, Red Hat Inc, Michael S. Tsirkin <mst@redhat.com>
3  *
4  * This work is licensed under the terms of the GNU LGPL, version 2.
5  */
6 #include <linux/pci_regs.h>
7 #include "pci.h"
8 #include "asm/pci.h"
9 
10 void pci_cmd_set_clr(struct pci_dev *dev, uint16_t set, uint16_t clr)
11 {
12 	uint16_t val = pci_config_readw(dev->bdf, PCI_COMMAND);
13 
14 	/* No overlap is allowed */
15 	assert((set & clr) == 0);
16 	val |= set;
17 	val &= ~clr;
18 
19 	pci_config_writew(dev->bdf, PCI_COMMAND, val);
20 }
21 
22 bool pci_dev_exists(pcidevaddr_t dev)
23 {
24 	return (pci_config_readw(dev, PCI_VENDOR_ID) != 0xffff &&
25 		pci_config_readw(dev, PCI_DEVICE_ID) != 0xffff);
26 }
27 
28 void pci_dev_init(struct pci_dev *dev, pcidevaddr_t bdf)
29 {
30        memset(dev, 0, sizeof(*dev));
31        dev->bdf = bdf;
32 }
33 
34 /* Scan bus look for a specific device. Only bus 0 scanned for now. */
35 pcidevaddr_t pci_find_dev(uint16_t vendor_id, uint16_t device_id)
36 {
37 	pcidevaddr_t dev;
38 
39 	for (dev = 0; dev < PCI_DEVFN_MAX; ++dev) {
40 		if (pci_config_readw(dev, PCI_VENDOR_ID) == vendor_id &&
41 		    pci_config_readw(dev, PCI_DEVICE_ID) == device_id)
42 			return dev;
43 	}
44 
45 	return PCIDEVADDR_INVALID;
46 }
47 
48 uint32_t pci_bar_mask(uint32_t bar)
49 {
50 	return (bar & PCI_BASE_ADDRESS_SPACE_IO) ?
51 		PCI_BASE_ADDRESS_IO_MASK : PCI_BASE_ADDRESS_MEM_MASK;
52 }
53 
54 uint32_t pci_bar_get(struct pci_dev *dev, int bar_num)
55 {
56 	return pci_config_readl(dev->bdf, PCI_BASE_ADDRESS_0 +
57 				bar_num * 4);
58 }
59 
60 phys_addr_t pci_bar_get_addr(struct pci_dev *dev, int bar_num)
61 {
62 	uint32_t bar = pci_bar_get(dev, bar_num);
63 	uint32_t mask = pci_bar_mask(bar);
64 	uint64_t addr = bar & mask;
65 	phys_addr_t phys_addr;
66 
67 	if (pci_bar_is64(dev, bar_num))
68 		addr |= (uint64_t)pci_bar_get(dev, bar_num + 1) << 32;
69 
70 	phys_addr = pci_translate_addr(dev->bdf, addr);
71 	assert(phys_addr != INVALID_PHYS_ADDR);
72 
73 	return phys_addr;
74 }
75 
76 void pci_bar_set_addr(struct pci_dev *dev, int bar_num, phys_addr_t addr)
77 {
78 	int off = PCI_BASE_ADDRESS_0 + bar_num * 4;
79 
80 	pci_config_writel(dev->bdf, off, (uint32_t)addr);
81 
82 	if (pci_bar_is64(dev, bar_num))
83 		pci_config_writel(dev->bdf, off + 4,
84 				  (uint32_t)(addr >> 32));
85 }
86 
87 /*
88  * To determine the amount of address space needed by a PCI device,
89  * one must save the original value of the BAR, write a value of
90  * all 1's to the register, and then read it back. The amount of
91  * memory can be then determined by masking the information bits,
92  * performing a bitwise NOT, and incrementing the value by 1.
93  *
94  * The following pci_bar_size_helper() and pci_bar_size() functions
95  * implement the algorithm.
96  */
97 static uint32_t pci_bar_size_helper(struct pci_dev *dev, int bar_num)
98 {
99 	int off = PCI_BASE_ADDRESS_0 + bar_num * 4;
100 	uint16_t bdf = dev->bdf;
101 	uint32_t bar, val;
102 
103 	bar = pci_config_readl(bdf, off);
104 	pci_config_writel(bdf, off, ~0u);
105 	val = pci_config_readl(bdf, off);
106 	pci_config_writel(bdf, off, bar);
107 
108 	return val;
109 }
110 
111 phys_addr_t pci_bar_size(struct pci_dev *dev, int bar_num)
112 {
113 	uint32_t bar, size;
114 
115 	size = pci_bar_size_helper(dev, bar_num);
116 	if (!size)
117 		return 0;
118 
119 	bar = pci_bar_get(dev, bar_num);
120 	size &= pci_bar_mask(bar);
121 
122 	if (pci_bar_is64(dev, bar_num)) {
123 		phys_addr_t size64 = pci_bar_size_helper(dev, bar_num + 1);
124 		size64 = (size64 << 32) | size;
125 
126 		return ~size64 + 1;
127 	} else {
128 		return ~size + 1;
129 	}
130 }
131 
132 bool pci_bar_is_memory(struct pci_dev *dev, int bar_num)
133 {
134 	uint32_t bar = pci_bar_get(dev, bar_num);
135 
136 	return !(bar & PCI_BASE_ADDRESS_SPACE_IO);
137 }
138 
139 bool pci_bar_is_valid(struct pci_dev *dev, int bar_num)
140 {
141 	return pci_bar_get(dev, bar_num);
142 }
143 
144 bool pci_bar_is64(struct pci_dev *dev, int bar_num)
145 {
146 	uint32_t bar = pci_bar_get(dev, bar_num);
147 
148 	if (bar & PCI_BASE_ADDRESS_SPACE_IO)
149 		return false;
150 
151 	return (bar & PCI_BASE_ADDRESS_MEM_TYPE_MASK) ==
152 		      PCI_BASE_ADDRESS_MEM_TYPE_64;
153 }
154 
155 void pci_bar_print(struct pci_dev *dev, int bar_num)
156 {
157 	phys_addr_t size, start, end;
158 	uint32_t bar;
159 
160 	size = pci_bar_size(dev, bar_num);
161 	if (!size)
162 		return;
163 
164 	bar = pci_bar_get(dev, bar_num);
165 	start = pci_bar_get_addr(dev, bar_num);
166 	end = start + size - 1;
167 
168 	if (pci_bar_is64(dev, bar_num)) {
169 		printf("BAR#%d,%d [%" PRIx64 "-%" PRIx64 " ",
170 		       bar_num, bar_num + 1, start, end);
171 	} else {
172 		printf("BAR#%d [%02x-%02x ",
173 		       bar_num, (uint32_t)start, (uint32_t)end);
174 	}
175 
176 	if (bar & PCI_BASE_ADDRESS_SPACE_IO) {
177 		printf("PIO");
178 	} else {
179 		printf("MEM");
180 		switch (bar & PCI_BASE_ADDRESS_MEM_TYPE_MASK) {
181 		case PCI_BASE_ADDRESS_MEM_TYPE_32:
182 			printf("32");
183 			break;
184 		case PCI_BASE_ADDRESS_MEM_TYPE_1M:
185 			printf("1M");
186 			break;
187 		case PCI_BASE_ADDRESS_MEM_TYPE_64:
188 			printf("64");
189 			break;
190 		default:
191 			assert(0);
192 		}
193 	}
194 
195 	if (bar & PCI_BASE_ADDRESS_MEM_PREFETCH)
196 		printf("/p");
197 
198 	printf("]");
199 }
200 
201 void pci_dev_print_id(pcidevaddr_t dev)
202 {
203 	printf("00.%02x.%1x %04x:%04x", dev / 8, dev % 8,
204 		pci_config_readw(dev, PCI_VENDOR_ID),
205 		pci_config_readw(dev, PCI_DEVICE_ID));
206 }
207 
208 static void pci_dev_print(pcidevaddr_t dev)
209 {
210 	uint8_t header = pci_config_readb(dev, PCI_HEADER_TYPE);
211 	uint8_t progif = pci_config_readb(dev, PCI_CLASS_PROG);
212 	uint8_t subclass = pci_config_readb(dev, PCI_CLASS_DEVICE);
213 	uint8_t class = pci_config_readb(dev, PCI_CLASS_DEVICE + 1);
214 	struct pci_dev pci_dev;
215 	int i;
216 
217 	pci_dev_init(&pci_dev, dev);
218 
219 	pci_dev_print_id(dev);
220 	printf(" type %02x progif %02x class %02x subclass %02x\n",
221 	       header, progif, class, subclass);
222 
223 	if ((header & PCI_HEADER_TYPE_MASK) != PCI_HEADER_TYPE_NORMAL)
224 		return;
225 
226 	for (i = 0; i < PCI_BAR_NUM; i++) {
227 		if (pci_bar_size(&pci_dev, i)) {
228 			printf("\t");
229 			pci_bar_print(&pci_dev, i);
230 			printf("\n");
231 		}
232 		if (pci_bar_is64(&pci_dev, i))
233 			i++;
234 	}
235 }
236 
237 void pci_print(void)
238 {
239 	pcidevaddr_t dev;
240 
241 	for (dev = 0; dev < PCI_DEVFN_MAX; ++dev) {
242 		if (pci_dev_exists(dev))
243 			pci_dev_print(dev);
244 	}
245 }
246 
247 void pci_scan_bars(struct pci_dev *dev)
248 {
249 	int i;
250 
251 	for (i = 0; i < PCI_BAR_NUM; i++) {
252 		if (!pci_bar_is_valid(dev, i))
253 			continue;
254 		dev->resource[i] = pci_bar_get_addr(dev, i);
255 		if (pci_bar_is64(dev, i)) {
256 			i++;
257 			dev->resource[i] = (phys_addr_t)0;
258 		}
259 	}
260 }
261 
262 void pci_enable_defaults(struct pci_dev *dev)
263 {
264 	pci_scan_bars(dev);
265 	/* Enable device DMA operations */
266 	pci_cmd_set_clr(dev, PCI_COMMAND_MASTER, 0);
267 }
268