Version:  2.0.40 2.2.26 2.4.37 3.5 3.6 3.7 3.8 3.9 3.10 3.11 3.12 3.13 3.14 3.15 3.16 3.17 3.18 3.19 4.0 4.1

Linux/drivers/misc/ioc4.c

  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) 2005-2006 Silicon Graphics, Inc.  All Rights Reserved.
  7  */
  8 
  9 /* This file contains the master driver module for use by SGI IOC4 subdrivers.
 10  *
 11  * It allocates any resources shared between multiple subdevices, and
 12  * provides accessor functions (where needed) and the like for those
 13  * resources.  It also provides a mechanism for the subdevice modules
 14  * to support loading and unloading.
 15  *
 16  * Non-shared resources (e.g. external interrupt A_INT_OUT register page
 17  * alias, serial port and UART registers) are handled by the subdevice
 18  * modules themselves.
 19  *
 20  * This is all necessary because IOC4 is not implemented as a multi-function
 21  * PCI device, but an amalgamation of disparate registers for several
 22  * types of device (ATA, serial, external interrupts).  The normal
 23  * resource management in the kernel doesn't have quite the right interfaces
 24  * to handle this situation (e.g. multiple modules can't claim the same
 25  * PCI ID), thus this IOC4 master module.
 26  */
 27 
 28 #include <linux/errno.h>
 29 #include <linux/module.h>
 30 #include <linux/pci.h>
 31 #include <linux/ioc4.h>
 32 #include <linux/ktime.h>
 33 #include <linux/slab.h>
 34 #include <linux/mutex.h>
 35 #include <linux/time.h>
 36 #include <asm/io.h>
 37 
 38 /***************
 39  * Definitions *
 40  ***************/
 41 
 42 /* Tweakable values */
 43 
 44 /* PCI bus speed detection/calibration */
 45 #define IOC4_CALIBRATE_COUNT 63         /* Calibration cycle period */
 46 #define IOC4_CALIBRATE_CYCLES 256       /* Average over this many cycles */
 47 #define IOC4_CALIBRATE_DISCARD 2        /* Discard first few cycles */
 48 #define IOC4_CALIBRATE_LOW_MHZ 25       /* Lower bound on bus speed sanity */
 49 #define IOC4_CALIBRATE_HIGH_MHZ 75      /* Upper bound on bus speed sanity */
 50 #define IOC4_CALIBRATE_DEFAULT_MHZ 66   /* Assumed if sanity check fails */
 51 
 52 /************************
 53  * Submodule management *
 54  ************************/
 55 
 56 static DEFINE_MUTEX(ioc4_mutex);
 57 
 58 static LIST_HEAD(ioc4_devices);
 59 static LIST_HEAD(ioc4_submodules);
 60 
 61 /* Register an IOC4 submodule */
 62 int
 63 ioc4_register_submodule(struct ioc4_submodule *is)
 64 {
 65         struct ioc4_driver_data *idd;
 66 
 67         mutex_lock(&ioc4_mutex);
 68         list_add(&is->is_list, &ioc4_submodules);
 69 
 70         /* Initialize submodule for each IOC4 */
 71         if (!is->is_probe)
 72                 goto out;
 73 
 74         list_for_each_entry(idd, &ioc4_devices, idd_list) {
 75                 if (is->is_probe(idd)) {
 76                         printk(KERN_WARNING
 77                                "%s: IOC4 submodule %s probe failed "
 78                                "for pci_dev %s",
 79                                __func__, module_name(is->is_owner),
 80                                pci_name(idd->idd_pdev));
 81                 }
 82         }
 83  out:
 84         mutex_unlock(&ioc4_mutex);
 85         return 0;
 86 }
 87 
 88 /* Unregister an IOC4 submodule */
 89 void
 90 ioc4_unregister_submodule(struct ioc4_submodule *is)
 91 {
 92         struct ioc4_driver_data *idd;
 93 
 94         mutex_lock(&ioc4_mutex);
 95         list_del(&is->is_list);
 96 
 97         /* Remove submodule for each IOC4 */
 98         if (!is->is_remove)
 99                 goto out;
100 
101         list_for_each_entry(idd, &ioc4_devices, idd_list) {
102                 if (is->is_remove(idd)) {
103                         printk(KERN_WARNING
104                                "%s: IOC4 submodule %s remove failed "
105                                "for pci_dev %s.\n",
106                                __func__, module_name(is->is_owner),
107                                pci_name(idd->idd_pdev));
108                 }
109         }
110  out:
111         mutex_unlock(&ioc4_mutex);
112 }
113 
114 /*********************
115  * Device management *
116  *********************/
117 
118 #define IOC4_CALIBRATE_LOW_LIMIT \
119         (1000*IOC4_EXTINT_COUNT_DIVISOR/IOC4_CALIBRATE_LOW_MHZ)
120 #define IOC4_CALIBRATE_HIGH_LIMIT \
121         (1000*IOC4_EXTINT_COUNT_DIVISOR/IOC4_CALIBRATE_HIGH_MHZ)
122 #define IOC4_CALIBRATE_DEFAULT \
123         (1000*IOC4_EXTINT_COUNT_DIVISOR/IOC4_CALIBRATE_DEFAULT_MHZ)
124 
125 #define IOC4_CALIBRATE_END \
126         (IOC4_CALIBRATE_CYCLES + IOC4_CALIBRATE_DISCARD)
127 
128 #define IOC4_INT_OUT_MODE_TOGGLE 0x7    /* Toggle INT_OUT every COUNT+1 ticks */
129 
130 /* Determines external interrupt output clock period of the PCI bus an
131  * IOC4 is attached to.  This value can be used to determine the PCI
132  * bus speed.
133  *
134  * IOC4 has a design feature that various internal timers are derived from
135  * the PCI bus clock.  This causes IOC4 device drivers to need to take the
136  * bus speed into account when setting various register values (e.g. INT_OUT
137  * register COUNT field, UART divisors, etc).  Since this information is
138  * needed by several subdrivers, it is determined by the main IOC4 driver,
139  * even though the following code utilizes external interrupt registers
140  * to perform the speed calculation.
141  */
142 static void
143 ioc4_clock_calibrate(struct ioc4_driver_data *idd)
144 {
145         union ioc4_int_out int_out;
146         union ioc4_gpcr gpcr;
147         unsigned int state, last_state;
148         uint64_t start, end, period;
149         unsigned int count;
150 
151         /* Enable output */
152         gpcr.raw = 0;
153         gpcr.fields.dir = IOC4_GPCR_DIR_0;
154         gpcr.fields.int_out_en = 1;
155         writel(gpcr.raw, &idd->idd_misc_regs->gpcr_s.raw);
156 
157         /* Reset to power-on state */
158         writel(0, &idd->idd_misc_regs->int_out.raw);
159         mmiowb();
160 
161         /* Set up square wave */
162         int_out.raw = 0;
163         int_out.fields.count = IOC4_CALIBRATE_COUNT;
164         int_out.fields.mode = IOC4_INT_OUT_MODE_TOGGLE;
165         int_out.fields.diag = 0;
166         writel(int_out.raw, &idd->idd_misc_regs->int_out.raw);
167         mmiowb();
168 
169         /* Check square wave period averaged over some number of cycles */
170         start = ktime_get_ns();
171         state = 1; /* make sure the first read isn't a rising edge */
172         for (count = 0; count <= IOC4_CALIBRATE_END; count++) {
173                 do { /* wait for a rising edge */
174                         last_state = state;
175                         int_out.raw = readl(&idd->idd_misc_regs->int_out.raw);
176                         state = int_out.fields.int_out;
177                 } while (last_state || !state);
178 
179                 /* discard the first few cycles */
180                 if (count == IOC4_CALIBRATE_DISCARD)
181                         start = ktime_get_ns();
182         }
183         end = ktime_get_ns();
184 
185         /* Calculation rearranged to preserve intermediate precision.
186          * Logically:
187          * 1. "end - start" gives us the measurement period over all
188          *    the square wave cycles.
189          * 2. Divide by number of square wave cycles to get the period
190          *    of a square wave cycle.
191          * 3. Divide by 2*(int_out.fields.count+1), which is the formula
192          *    by which the IOC4 generates the square wave, to get the
193          *    period of an IOC4 INT_OUT count.
194          */
195         period = (end - start) /
196                 (IOC4_CALIBRATE_CYCLES * 2 * (IOC4_CALIBRATE_COUNT + 1));
197 
198         /* Bounds check the result. */
199         if (period > IOC4_CALIBRATE_LOW_LIMIT ||
200             period < IOC4_CALIBRATE_HIGH_LIMIT) {
201                 printk(KERN_INFO
202                        "IOC4 %s: Clock calibration failed.  Assuming"
203                        "PCI clock is %d ns.\n",
204                        pci_name(idd->idd_pdev),
205                        IOC4_CALIBRATE_DEFAULT / IOC4_EXTINT_COUNT_DIVISOR);
206                 period = IOC4_CALIBRATE_DEFAULT;
207         } else {
208                 u64 ns = period;
209 
210                 do_div(ns, IOC4_EXTINT_COUNT_DIVISOR);
211                 printk(KERN_DEBUG
212                        "IOC4 %s: PCI clock is %llu ns.\n",
213                        pci_name(idd->idd_pdev), (unsigned long long)ns);
214         }
215 
216         /* Remember results.  We store the extint clock period rather
217          * than the PCI clock period so that greater precision is
218          * retained.  Divide by IOC4_EXTINT_COUNT_DIVISOR to get
219          * PCI clock period.
220          */
221         idd->count_period = period;
222 }
223 
224 /* There are three variants of IOC4 cards: IO9, IO10, and PCI-RT.
225  * Each brings out different combinations of IOC4 signals, thus.
226  * the IOC4 subdrivers need to know to which we're attached.
227  *
228  * We look for the presence of a SCSI (IO9) or SATA (IO10) controller
229  * on the same PCI bus at slot number 3 to differentiate IO9 from IO10.
230  * If neither is present, it's a PCI-RT.
231  */
232 static unsigned int
233 ioc4_variant(struct ioc4_driver_data *idd)
234 {
235         struct pci_dev *pdev = NULL;
236         int found = 0;
237 
238         /* IO9: Look for a QLogic ISP 12160 at the same bus and slot 3. */
239         do {
240                 pdev = pci_get_device(PCI_VENDOR_ID_QLOGIC,
241                                       PCI_DEVICE_ID_QLOGIC_ISP12160, pdev);
242                 if (pdev &&
243                     idd->idd_pdev->bus->number == pdev->bus->number &&
244                     3 == PCI_SLOT(pdev->devfn))
245                         found = 1;
246         } while (pdev && !found);
247         if (NULL != pdev) {
248                 pci_dev_put(pdev);
249                 return IOC4_VARIANT_IO9;
250         }
251 
252         /* IO10: Look for a Vitesse VSC 7174 at the same bus and slot 3. */
253         pdev = NULL;
254         do {
255                 pdev = pci_get_device(PCI_VENDOR_ID_VITESSE,
256                                       PCI_DEVICE_ID_VITESSE_VSC7174, pdev);
257                 if (pdev &&
258                     idd->idd_pdev->bus->number == pdev->bus->number &&
259                     3 == PCI_SLOT(pdev->devfn))
260                         found = 1;
261         } while (pdev && !found);
262         if (NULL != pdev) {
263                 pci_dev_put(pdev);
264                 return IOC4_VARIANT_IO10;
265         }
266 
267         /* PCI-RT: No SCSI/SATA controller will be present */
268         return IOC4_VARIANT_PCI_RT;
269 }
270 
271 static void
272 ioc4_load_modules(struct work_struct *work)
273 {
274         request_module("sgiioc4");
275 }
276 
277 static DECLARE_WORK(ioc4_load_modules_work, ioc4_load_modules);
278 
279 /* Adds a new instance of an IOC4 card */
280 static int
281 ioc4_probe(struct pci_dev *pdev, const struct pci_device_id *pci_id)
282 {
283         struct ioc4_driver_data *idd;
284         struct ioc4_submodule *is;
285         uint32_t pcmd;
286         int ret;
287 
288         /* Enable IOC4 and take ownership of it */
289         if ((ret = pci_enable_device(pdev))) {
290                 printk(KERN_WARNING
291                        "%s: Failed to enable IOC4 device for pci_dev %s.\n",
292                        __func__, pci_name(pdev));
293                 goto out;
294         }
295         pci_set_master(pdev);
296 
297         /* Set up per-IOC4 data */
298         idd = kmalloc(sizeof(struct ioc4_driver_data), GFP_KERNEL);
299         if (!idd) {
300                 printk(KERN_WARNING
301                        "%s: Failed to allocate IOC4 data for pci_dev %s.\n",
302                        __func__, pci_name(pdev));
303                 ret = -ENODEV;
304                 goto out_idd;
305         }
306         idd->idd_pdev = pdev;
307         idd->idd_pci_id = pci_id;
308 
309         /* Map IOC4 misc registers.  These are shared between subdevices
310          * so the main IOC4 module manages them.
311          */
312         idd->idd_bar0 = pci_resource_start(idd->idd_pdev, 0);
313         if (!idd->idd_bar0) {
314                 printk(KERN_WARNING
315                        "%s: Unable to find IOC4 misc resource "
316                        "for pci_dev %s.\n",
317                        __func__, pci_name(idd->idd_pdev));
318                 ret = -ENODEV;
319                 goto out_pci;
320         }
321         if (!request_mem_region(idd->idd_bar0, sizeof(struct ioc4_misc_regs),
322                             "ioc4_misc")) {
323                 printk(KERN_WARNING
324                        "%s: Unable to request IOC4 misc region "
325                        "for pci_dev %s.\n",
326                        __func__, pci_name(idd->idd_pdev));
327                 ret = -ENODEV;
328                 goto out_pci;
329         }
330         idd->idd_misc_regs = ioremap(idd->idd_bar0,
331                                      sizeof(struct ioc4_misc_regs));
332         if (!idd->idd_misc_regs) {
333                 printk(KERN_WARNING
334                        "%s: Unable to remap IOC4 misc region "
335                        "for pci_dev %s.\n",
336                        __func__, pci_name(idd->idd_pdev));
337                 ret = -ENODEV;
338                 goto out_misc_region;
339         }
340 
341         /* Failsafe portion of per-IOC4 initialization */
342 
343         /* Detect card variant */
344         idd->idd_variant = ioc4_variant(idd);
345         printk(KERN_INFO "IOC4 %s: %s card detected.\n", pci_name(pdev),
346                idd->idd_variant == IOC4_VARIANT_IO9 ? "IO9" :
347                idd->idd_variant == IOC4_VARIANT_PCI_RT ? "PCI-RT" :
348                idd->idd_variant == IOC4_VARIANT_IO10 ? "IO10" : "unknown");
349 
350         /* Initialize IOC4 */
351         pci_read_config_dword(idd->idd_pdev, PCI_COMMAND, &pcmd);
352         pci_write_config_dword(idd->idd_pdev, PCI_COMMAND,
353                                pcmd | PCI_COMMAND_PARITY | PCI_COMMAND_SERR);
354 
355         /* Determine PCI clock */
356         ioc4_clock_calibrate(idd);
357 
358         /* Disable/clear all interrupts.  Need to do this here lest
359          * one submodule request the shared IOC4 IRQ, but interrupt
360          * is generated by a different subdevice.
361          */
362         /* Disable */
363         writel(~0, &idd->idd_misc_regs->other_iec.raw);
364         writel(~0, &idd->idd_misc_regs->sio_iec);
365         /* Clear (i.e. acknowledge) */
366         writel(~0, &idd->idd_misc_regs->other_ir.raw);
367         writel(~0, &idd->idd_misc_regs->sio_ir);
368 
369         /* Track PCI-device specific data */
370         idd->idd_serial_data = NULL;
371         pci_set_drvdata(idd->idd_pdev, idd);
372 
373         mutex_lock(&ioc4_mutex);
374         list_add_tail(&idd->idd_list, &ioc4_devices);
375 
376         /* Add this IOC4 to all submodules */
377         list_for_each_entry(is, &ioc4_submodules, is_list) {
378                 if (is->is_probe && is->is_probe(idd)) {
379                         printk(KERN_WARNING
380                                "%s: IOC4 submodule 0x%s probe failed "
381                                "for pci_dev %s.\n",
382                                __func__, module_name(is->is_owner),
383                                pci_name(idd->idd_pdev));
384                 }
385         }
386         mutex_unlock(&ioc4_mutex);
387 
388         /* Request sgiioc4 IDE driver on boards that bring that functionality
389          * off of IOC4.  The root filesystem may be hosted on a drive connected
390          * to IOC4, so we need to make sure the sgiioc4 driver is loaded as it
391          * won't be picked up by modprobes due to the ioc4 module owning the
392          * PCI device.
393          */
394         if (idd->idd_variant != IOC4_VARIANT_PCI_RT) {
395                 /* Request the module from a work procedure as the modprobe
396                  * goes out to a userland helper and that will hang if done
397                  * directly from ioc4_probe().
398                  */
399                 printk(KERN_INFO "IOC4 loading sgiioc4 submodule\n");
400                 schedule_work(&ioc4_load_modules_work);
401         }
402 
403         return 0;
404 
405 out_misc_region:
406         release_mem_region(idd->idd_bar0, sizeof(struct ioc4_misc_regs));
407 out_pci:
408         kfree(idd);
409 out_idd:
410         pci_disable_device(pdev);
411 out:
412         return ret;
413 }
414 
415 /* Removes a particular instance of an IOC4 card. */
416 static void
417 ioc4_remove(struct pci_dev *pdev)
418 {
419         struct ioc4_submodule *is;
420         struct ioc4_driver_data *idd;
421 
422         idd = pci_get_drvdata(pdev);
423 
424         /* Remove this IOC4 from all submodules */
425         mutex_lock(&ioc4_mutex);
426         list_for_each_entry(is, &ioc4_submodules, is_list) {
427                 if (is->is_remove && is->is_remove(idd)) {
428                         printk(KERN_WARNING
429                                "%s: IOC4 submodule 0x%s remove failed "
430                                "for pci_dev %s.\n",
431                                __func__, module_name(is->is_owner),
432                                pci_name(idd->idd_pdev));
433                 }
434         }
435         mutex_unlock(&ioc4_mutex);
436 
437         /* Release resources */
438         iounmap(idd->idd_misc_regs);
439         if (!idd->idd_bar0) {
440                 printk(KERN_WARNING
441                        "%s: Unable to get IOC4 misc mapping for pci_dev %s. "
442                        "Device removal may be incomplete.\n",
443                        __func__, pci_name(idd->idd_pdev));
444         }
445         release_mem_region(idd->idd_bar0, sizeof(struct ioc4_misc_regs));
446 
447         /* Disable IOC4 and relinquish */
448         pci_disable_device(pdev);
449 
450         /* Remove and free driver data */
451         mutex_lock(&ioc4_mutex);
452         list_del(&idd->idd_list);
453         mutex_unlock(&ioc4_mutex);
454         kfree(idd);
455 }
456 
457 static struct pci_device_id ioc4_id_table[] = {
458         {PCI_VENDOR_ID_SGI, PCI_DEVICE_ID_SGI_IOC4, PCI_ANY_ID,
459          PCI_ANY_ID, 0x0b4000, 0xFFFFFF},
460         {0}
461 };
462 
463 static struct pci_driver ioc4_driver = {
464         .name = "IOC4",
465         .id_table = ioc4_id_table,
466         .probe = ioc4_probe,
467         .remove = ioc4_remove,
468 };
469 
470 MODULE_DEVICE_TABLE(pci, ioc4_id_table);
471 
472 /*********************
473  * Module management *
474  *********************/
475 
476 /* Module load */
477 static int __init
478 ioc4_init(void)
479 {
480         return pci_register_driver(&ioc4_driver);
481 }
482 
483 /* Module unload */
484 static void __exit
485 ioc4_exit(void)
486 {
487         /* Ensure ioc4_load_modules() has completed before exiting */
488         flush_work(&ioc4_load_modules_work);
489         pci_unregister_driver(&ioc4_driver);
490 }
491 
492 module_init(ioc4_init);
493 module_exit(ioc4_exit);
494 
495 MODULE_AUTHOR("Brent Casavant - Silicon Graphics, Inc. <bcasavan@sgi.com>");
496 MODULE_DESCRIPTION("PCI driver master module for SGI IOC4 Base-IO Card");
497 MODULE_LICENSE("GPL");
498 
499 EXPORT_SYMBOL(ioc4_register_submodule);
500 EXPORT_SYMBOL(ioc4_unregister_submodule);
501 

This page was automatically generated by LXR 0.3.1 (source).  •  Linux is a registered trademark of Linus Torvalds  •  Contact us