1 /*
2 * BRIEF MODULE DESCRIPTION
3 * Alchemy/AMD Au1xx0 PCI support.
4 *
5 * Copyright 2001-2003, 2007-2008 MontaVista Software Inc.
6 * Author: MontaVista Software, Inc. <source@mvista.com>
7 *
8 * Support for all devices (greater than 16) added by David Gathright.
9 *
10 * This program is free software; you can redistribute it and/or modify it
11 * under the terms of the GNU General Public License as published by the
12 * Free Software Foundation; either version 2 of the License, or (at your
13 * option) any later version.
14 *
15 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED
16 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
17 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN
18 * NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
21 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
22 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 *
26 * You should have received a copy of the GNU General Public License along
27 * with this program; if not, write to the Free Software Foundation, Inc.,
28 * 675 Mass Ave, Cambridge, MA 02139, USA.
29 */
30
31 #include <linux/types.h>
32 #include <linux/pci.h>
33 #include <linux/kernel.h>
34 #include <linux/init.h>
35 #include <linux/vmalloc.h>
36
37 #include <asm/mach-au1x00/au1000.h>
38
39 #undef DEBUG
40 #ifdef DEBUG
41 #define DBG(x...) printk(KERN_DEBUG x)
42 #else
43 #define DBG(x...)
44 #endif
45
46 #define PCI_ACCESS_READ 0
47 #define PCI_ACCESS_WRITE 1
48
49 int (*board_pci_idsel)(unsigned int devsel, int assert);
50
mod_wired_entry(int entry,unsigned long entrylo0,unsigned long entrylo1,unsigned long entryhi,unsigned long pagemask)51 void mod_wired_entry(int entry, unsigned long entrylo0,
52 unsigned long entrylo1, unsigned long entryhi,
53 unsigned long pagemask)
54 {
55 unsigned long old_pagemask;
56 unsigned long old_ctx;
57
58 /* Save old context and create impossible VPN2 value */
59 old_ctx = read_c0_entryhi() & 0xff;
60 old_pagemask = read_c0_pagemask();
61 write_c0_index(entry);
62 write_c0_pagemask(pagemask);
63 write_c0_entryhi(entryhi);
64 write_c0_entrylo0(entrylo0);
65 write_c0_entrylo1(entrylo1);
66 tlb_write_indexed();
67 write_c0_entryhi(old_ctx);
68 write_c0_pagemask(old_pagemask);
69 }
70
71 static struct vm_struct *pci_cfg_vm;
72 static int pci_cfg_wired_entry;
73 static unsigned long last_entryLo0, last_entryLo1;
74
75 /*
76 * We can't ioremap the entire pci config space because it's too large.
77 * Nor can we call ioremap dynamically because some device drivers use
78 * the PCI config routines from within interrupt handlers and that
79 * becomes a problem in get_vm_area(). We use one wired TLB to handle
80 * all config accesses for all busses.
81 */
au1x_pci_cfg_init(void)82 void __init au1x_pci_cfg_init(void)
83 {
84 /* Reserve a wired entry for PCI config accesses */
85 pci_cfg_vm = get_vm_area(0x2000, VM_IOREMAP);
86 if (!pci_cfg_vm)
87 panic(KERN_ERR "PCI unable to get vm area\n");
88 pci_cfg_wired_entry = read_c0_wired();
89 add_wired_entry(0, 0, (unsigned long)pci_cfg_vm->addr, PM_4K);
90 last_entryLo0 = last_entryLo1 = 0xffffffff;
91 }
92
config_access(unsigned char access_type,struct pci_bus * bus,unsigned int dev_fn,unsigned char where,u32 * data)93 static int config_access(unsigned char access_type, struct pci_bus *bus,
94 unsigned int dev_fn, unsigned char where, u32 *data)
95 {
96 #if defined(CONFIG_SOC_AU1500) || defined(CONFIG_SOC_AU1550)
97 unsigned int device = PCI_SLOT(dev_fn);
98 unsigned int function = PCI_FUNC(dev_fn);
99 unsigned long offset, status;
100 unsigned long cfg_base;
101 unsigned long flags;
102 int error = PCIBIOS_SUCCESSFUL;
103 unsigned long entryLo0, entryLo1;
104
105 if (device > 19) {
106 *data = 0xffffffff;
107 return -1;
108 }
109
110 local_irq_save(flags);
111 au_writel(((0x2000 << 16) | (au_readl(Au1500_PCI_STATCMD) & 0xffff)),
112 Au1500_PCI_STATCMD);
113 au_sync_udelay(1);
114
115 /*
116 * Allow board vendors to implement their own off-chip IDSEL.
117 * If it doesn't succeed, may as well bail out at this point.
118 */
119 if (board_pci_idsel && board_pci_idsel(device, 1) == 0) {
120 *data = 0xffffffff;
121 local_irq_restore(flags);
122 return -1;
123 }
124
125 /* Setup the config window */
126 if (bus->number == 0)
127 cfg_base = (1 << device) << 11;
128 else
129 cfg_base = 0x80000000 | (bus->number << 16) | (device << 11);
130
131 /* Setup the lower bits of the 36-bit address */
132 offset = (function << 8) | (where & ~0x3);
133 /* Pick up any address that falls below the page mask */
134 offset |= cfg_base & ~PAGE_MASK;
135
136 /* Page boundary */
137 cfg_base = cfg_base & PAGE_MASK;
138
139 /*
140 * To improve performance, if the current device is the same as
141 * the last device accessed, we don't touch the TLB.
142 */
143 entryLo0 = (6 << 26) | (cfg_base >> 6) | (2 << 3) | 7;
144 entryLo1 = (6 << 26) | (cfg_base >> 6) | (0x1000 >> 6) | (2 << 3) | 7;
145 if ((entryLo0 != last_entryLo0) || (entryLo1 != last_entryLo1)) {
146 mod_wired_entry(pci_cfg_wired_entry, entryLo0, entryLo1,
147 (unsigned long)pci_cfg_vm->addr, PM_4K);
148 last_entryLo0 = entryLo0;
149 last_entryLo1 = entryLo1;
150 }
151
152 if (access_type == PCI_ACCESS_WRITE)
153 au_writel(*data, (int)(pci_cfg_vm->addr + offset));
154 else
155 *data = au_readl((int)(pci_cfg_vm->addr + offset));
156
157 au_sync_udelay(2);
158
159 DBG("cfg_access %d bus->number %u dev %u at %x *data %x conf %lx\n",
160 access_type, bus->number, device, where, *data, offset);
161
162 /* Check master abort */
163 status = au_readl(Au1500_PCI_STATCMD);
164
165 if (status & (1 << 29)) {
166 *data = 0xffffffff;
167 error = -1;
168 DBG("Au1x Master Abort\n");
169 } else if ((status >> 28) & 0xf) {
170 DBG("PCI ERR detected: device %u, status %lx\n",
171 device, (status >> 28) & 0xf);
172
173 /* Clear errors */
174 au_writel(status & 0xf000ffff, Au1500_PCI_STATCMD);
175
176 *data = 0xffffffff;
177 error = -1;
178 }
179
180 /* Take away the IDSEL. */
181 if (board_pci_idsel)
182 (void)board_pci_idsel(device, 0);
183
184 local_irq_restore(flags);
185 return error;
186 #endif
187 }
188
read_config_byte(struct pci_bus * bus,unsigned int devfn,int where,u8 * val)189 static int read_config_byte(struct pci_bus *bus, unsigned int devfn,
190 int where, u8 *val)
191 {
192 u32 data;
193 int ret;
194
195 ret = config_access(PCI_ACCESS_READ, bus, devfn, where, &data);
196 if (where & 1)
197 data >>= 8;
198 if (where & 2)
199 data >>= 16;
200 *val = data & 0xff;
201 return ret;
202 }
203
read_config_word(struct pci_bus * bus,unsigned int devfn,int where,u16 * val)204 static int read_config_word(struct pci_bus *bus, unsigned int devfn,
205 int where, u16 *val)
206 {
207 u32 data;
208 int ret;
209
210 ret = config_access(PCI_ACCESS_READ, bus, devfn, where, &data);
211 if (where & 2)
212 data >>= 16;
213 *val = data & 0xffff;
214 return ret;
215 }
216
read_config_dword(struct pci_bus * bus,unsigned int devfn,int where,u32 * val)217 static int read_config_dword(struct pci_bus *bus, unsigned int devfn,
218 int where, u32 *val)
219 {
220 int ret;
221
222 ret = config_access(PCI_ACCESS_READ, bus, devfn, where, val);
223 return ret;
224 }
225
write_config_byte(struct pci_bus * bus,unsigned int devfn,int where,u8 val)226 static int write_config_byte(struct pci_bus *bus, unsigned int devfn,
227 int where, u8 val)
228 {
229 u32 data = 0;
230
231 if (config_access(PCI_ACCESS_READ, bus, devfn, where, &data))
232 return -1;
233
234 data = (data & ~(0xff << ((where & 3) << 3))) |
235 (val << ((where & 3) << 3));
236
237 if (config_access(PCI_ACCESS_WRITE, bus, devfn, where, &data))
238 return -1;
239
240 return PCIBIOS_SUCCESSFUL;
241 }
242
write_config_word(struct pci_bus * bus,unsigned int devfn,int where,u16 val)243 static int write_config_word(struct pci_bus *bus, unsigned int devfn,
244 int where, u16 val)
245 {
246 u32 data = 0;
247
248 if (config_access(PCI_ACCESS_READ, bus, devfn, where, &data))
249 return -1;
250
251 data = (data & ~(0xffff << ((where & 3) << 3))) |
252 (val << ((where & 3) << 3));
253
254 if (config_access(PCI_ACCESS_WRITE, bus, devfn, where, &data))
255 return -1;
256
257 return PCIBIOS_SUCCESSFUL;
258 }
259
write_config_dword(struct pci_bus * bus,unsigned int devfn,int where,u32 val)260 static int write_config_dword(struct pci_bus *bus, unsigned int devfn,
261 int where, u32 val)
262 {
263 if (config_access(PCI_ACCESS_WRITE, bus, devfn, where, &val))
264 return -1;
265
266 return PCIBIOS_SUCCESSFUL;
267 }
268
config_read(struct pci_bus * bus,unsigned int devfn,int where,int size,u32 * val)269 static int config_read(struct pci_bus *bus, unsigned int devfn,
270 int where, int size, u32 *val)
271 {
272 switch (size) {
273 case 1: {
274 u8 _val;
275 int rc = read_config_byte(bus, devfn, where, &_val);
276
277 *val = _val;
278 return rc;
279 }
280 case 2: {
281 u16 _val;
282 int rc = read_config_word(bus, devfn, where, &_val);
283
284 *val = _val;
285 return rc;
286 }
287 default:
288 return read_config_dword(bus, devfn, where, val);
289 }
290 }
291
config_write(struct pci_bus * bus,unsigned int devfn,int where,int size,u32 val)292 static int config_write(struct pci_bus *bus, unsigned int devfn,
293 int where, int size, u32 val)
294 {
295 switch (size) {
296 case 1:
297 return write_config_byte(bus, devfn, where, (u8) val);
298 case 2:
299 return write_config_word(bus, devfn, where, (u16) val);
300 default:
301 return write_config_dword(bus, devfn, where, val);
302 }
303 }
304
305 struct pci_ops au1x_pci_ops = {
306 config_read,
307 config_write
308 };
309