xref: /openbmc/linux/arch/parisc/kernel/pci.c (revision 0f4630f3)
1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (C) 1997, 1998 Ralf Baechle
7  * Copyright (C) 1999 SuSE GmbH
8  * Copyright (C) 1999-2001 Hewlett-Packard Company
9  * Copyright (C) 1999-2001 Grant Grundler
10  */
11 #include <linux/eisa.h>
12 #include <linux/init.h>
13 #include <linux/module.h>
14 #include <linux/kernel.h>
15 #include <linux/pci.h>
16 #include <linux/types.h>
17 
18 #include <asm/io.h>
19 #include <asm/superio.h>
20 
21 #define DEBUG_RESOURCES 0
22 #define DEBUG_CONFIG 0
23 
24 #if DEBUG_CONFIG
25 # define DBGC(x...)	printk(KERN_DEBUG x)
26 #else
27 # define DBGC(x...)
28 #endif
29 
30 
31 #if DEBUG_RESOURCES
32 #define DBG_RES(x...)	printk(KERN_DEBUG x)
33 #else
34 #define DBG_RES(x...)
35 #endif
36 
37 /* To be used as: mdelay(pci_post_reset_delay);
38  *
39  * post_reset is the time the kernel should stall to prevent anyone from
40  * accessing the PCI bus once #RESET is de-asserted.
41  * PCI spec somewhere says 1 second but with multi-PCI bus systems,
42  * this makes the boot time much longer than necessary.
43  * 20ms seems to work for all the HP PCI implementations to date.
44  *
45  * #define pci_post_reset_delay 50
46  */
47 
48 struct pci_port_ops *pci_port __read_mostly;
49 struct pci_bios_ops *pci_bios __read_mostly;
50 
51 static int pci_hba_count __read_mostly;
52 
53 /* parisc_pci_hba used by pci_port->in/out() ops to lookup bus data.  */
54 #define PCI_HBA_MAX 32
55 static struct pci_hba_data *parisc_pci_hba[PCI_HBA_MAX] __read_mostly;
56 
57 
58 /********************************************************************
59 **
60 ** I/O port space support
61 **
62 *********************************************************************/
63 
64 /* EISA port numbers and PCI port numbers share the same interface.  Some
65  * machines have both EISA and PCI adapters installed.  Rather than turn
66  * pci_port into an array, we reserve bus 0 for EISA and call the EISA
67  * routines if the access is to a port on bus 0.  We don't want to fix
68  * EISA and ISA drivers which assume port space is <= 0xffff.
69  */
70 
71 #ifdef CONFIG_EISA
72 #define EISA_IN(size) if (EISA_bus && (b == 0)) return eisa_in##size(addr)
73 #define EISA_OUT(size) if (EISA_bus && (b == 0)) return eisa_out##size(d, addr)
74 #else
75 #define EISA_IN(size)
76 #define EISA_OUT(size)
77 #endif
78 
79 #define PCI_PORT_IN(type, size) \
80 u##size in##type (int addr) \
81 { \
82 	int b = PCI_PORT_HBA(addr); \
83 	EISA_IN(size); \
84 	if (!parisc_pci_hba[b]) return (u##size) -1; \
85 	return pci_port->in##type(parisc_pci_hba[b], PCI_PORT_ADDR(addr)); \
86 } \
87 EXPORT_SYMBOL(in##type);
88 
89 PCI_PORT_IN(b,  8)
90 PCI_PORT_IN(w, 16)
91 PCI_PORT_IN(l, 32)
92 
93 
94 #define PCI_PORT_OUT(type, size) \
95 void out##type (u##size d, int addr) \
96 { \
97 	int b = PCI_PORT_HBA(addr); \
98 	EISA_OUT(size); \
99 	if (!parisc_pci_hba[b]) return; \
100 	pci_port->out##type(parisc_pci_hba[b], PCI_PORT_ADDR(addr), d); \
101 } \
102 EXPORT_SYMBOL(out##type);
103 
104 PCI_PORT_OUT(b,  8)
105 PCI_PORT_OUT(w, 16)
106 PCI_PORT_OUT(l, 32)
107 
108 
109 
110 /*
111  * BIOS32 replacement.
112  */
113 static int __init pcibios_init(void)
114 {
115 	if (!pci_bios)
116 		return -1;
117 
118 	if (pci_bios->init) {
119 		pci_bios->init();
120 	} else {
121 		printk(KERN_WARNING "pci_bios != NULL but init() is!\n");
122 	}
123 
124 	/* Set the CLS for PCI as early as possible. */
125 	pci_cache_line_size = pci_dfl_cache_line_size;
126 
127 	return 0;
128 }
129 
130 
131 /* Called from pci_do_scan_bus() *after* walking a bus but before walking PPBs. */
132 void pcibios_fixup_bus(struct pci_bus *bus)
133 {
134 	if (pci_bios->fixup_bus) {
135 		pci_bios->fixup_bus(bus);
136 	} else {
137 		printk(KERN_WARNING "pci_bios != NULL but fixup_bus() is!\n");
138 	}
139 }
140 
141 
142 /*
143  * Called by pci_set_master() - a driver interface.
144  *
145  * Legacy PDC guarantees to set:
146  *	Map Memory BAR's into PA IO space.
147  *	Map Expansion ROM BAR into one common PA IO space per bus.
148  *	Map IO BAR's into PCI IO space.
149  *	Command (see below)
150  *	Cache Line Size
151  *	Latency Timer
152  *	Interrupt Line
153  *	PPB: secondary latency timer, io/mmio base/limit,
154  *		bus numbers, bridge control
155  *
156  */
157 void pcibios_set_master(struct pci_dev *dev)
158 {
159 	u8 lat;
160 
161 	/* If someone already mucked with this, don't touch it. */
162 	pci_read_config_byte(dev, PCI_LATENCY_TIMER, &lat);
163 	if (lat >= 16) return;
164 
165 	/*
166 	** HP generally has fewer devices on the bus than other architectures.
167 	** upper byte is PCI_LATENCY_TIMER.
168 	*/
169 	pci_write_config_word(dev, PCI_CACHE_LINE_SIZE,
170 			      (0x80 << 8) | pci_cache_line_size);
171 }
172 
173 
174 /*
175  * pcibios align resources() is called every time generic PCI code
176  * wants to generate a new address. The process of looking for
177  * an available address, each candidate is first "aligned" and
178  * then checked if the resource is available until a match is found.
179  *
180  * Since we are just checking candidates, don't use any fields other
181  * than res->start.
182  */
183 resource_size_t pcibios_align_resource(void *data, const struct resource *res,
184 				resource_size_t size, resource_size_t alignment)
185 {
186 	resource_size_t mask, align, start = res->start;
187 
188 	DBG_RES("pcibios_align_resource(%s, (%p) [%lx,%lx]/%x, 0x%lx, 0x%lx)\n",
189 		pci_name(((struct pci_dev *) data)),
190 		res->parent, res->start, res->end,
191 		(int) res->flags, size, alignment);
192 
193 	/* If it's not IO, then it's gotta be MEM */
194 	align = (res->flags & IORESOURCE_IO) ? PCIBIOS_MIN_IO : PCIBIOS_MIN_MEM;
195 
196 	/* Align to largest of MIN or input size */
197 	mask = max(alignment, align) - 1;
198 	start += mask;
199 	start &= ~mask;
200 
201 	return start;
202 }
203 
204 
205 int pci_mmap_page_range(struct pci_dev *dev, struct vm_area_struct *vma,
206 			enum pci_mmap_state mmap_state, int write_combine)
207 {
208 	unsigned long prot;
209 
210 	/*
211 	 * I/O space can be accessed via normal processor loads and stores on
212 	 * this platform but for now we elect not to do this and portable
213 	 * drivers should not do this anyway.
214 	 */
215 	if (mmap_state == pci_mmap_io)
216 		return -EINVAL;
217 
218 	if (write_combine)
219 		return -EINVAL;
220 
221 	/*
222 	 * Ignore write-combine; for now only return uncached mappings.
223 	 */
224 	prot = pgprot_val(vma->vm_page_prot);
225 	prot |= _PAGE_NO_CACHE;
226 	vma->vm_page_prot = __pgprot(prot);
227 
228 	return remap_pfn_range(vma, vma->vm_start, vma->vm_pgoff,
229 		vma->vm_end - vma->vm_start, vma->vm_page_prot);
230 }
231 
232 /*
233  * A driver is enabling the device.  We make sure that all the appropriate
234  * bits are set to allow the device to operate as the driver is expecting.
235  * We enable the port IO and memory IO bits if the device has any BARs of
236  * that type, and we enable the PERR and SERR bits unconditionally.
237  * Drivers that do not need parity (eg graphics and possibly networking)
238  * can clear these bits if they want.
239  */
240 int pcibios_enable_device(struct pci_dev *dev, int mask)
241 {
242 	int err;
243 	u16 cmd, old_cmd;
244 
245 	err = pci_enable_resources(dev, mask);
246 	if (err < 0)
247 		return err;
248 
249 	pci_read_config_word(dev, PCI_COMMAND, &cmd);
250 	old_cmd = cmd;
251 
252 	cmd |= (PCI_COMMAND_SERR | PCI_COMMAND_PARITY);
253 
254 #if 0
255 	/* If bridge/bus controller has FBB enabled, child must too. */
256 	if (dev->bus->bridge_ctl & PCI_BRIDGE_CTL_FAST_BACK)
257 		cmd |= PCI_COMMAND_FAST_BACK;
258 #endif
259 
260 	if (cmd != old_cmd) {
261 		dev_info(&dev->dev, "enabling SERR and PARITY (%04x -> %04x)\n",
262 			old_cmd, cmd);
263 		pci_write_config_word(dev, PCI_COMMAND, cmd);
264 	}
265 	return 0;
266 }
267 
268 
269 /* PA-RISC specific */
270 void pcibios_register_hba(struct pci_hba_data *hba)
271 {
272 	if (pci_hba_count >= PCI_HBA_MAX) {
273 		printk(KERN_ERR "PCI: Too many Host Bus Adapters\n");
274 		return;
275 	}
276 
277 	parisc_pci_hba[pci_hba_count] = hba;
278 	hba->hba_num = pci_hba_count++;
279 }
280 
281 subsys_initcall(pcibios_init);
282