xref: /openbmc/linux/drivers/pci/pci-acpi.c (revision 384740dc)
1 /*
2  * File:	pci-acpi.c
3  * Purpose:	Provide PCI support in ACPI
4  *
5  * Copyright (C) 2005 David Shaohua Li <shaohua.li@intel.com>
6  * Copyright (C) 2004 Tom Long Nguyen <tom.l.nguyen@intel.com>
7  * Copyright (C) 2004 Intel Corp.
8  */
9 
10 #include <linux/delay.h>
11 #include <linux/init.h>
12 #include <linux/pci.h>
13 #include <linux/module.h>
14 #include <linux/pci-aspm.h>
15 #include <acpi/acpi.h>
16 #include <acpi/acnamesp.h>
17 #include <acpi/acresrc.h>
18 #include <acpi/acpi_bus.h>
19 
20 #include <linux/pci-acpi.h>
21 #include "pci.h"
22 
23 struct acpi_osc_data {
24 	acpi_handle handle;
25 	u32 support_set;
26 	u32 control_set;
27 	int is_queried;
28 	u32 query_result;
29 	struct list_head sibiling;
30 };
31 static LIST_HEAD(acpi_osc_data_list);
32 
33 struct acpi_osc_args {
34 	u32 capbuf[3];
35 	u32 query_result;
36 };
37 
38 static struct acpi_osc_data *acpi_get_osc_data(acpi_handle handle)
39 {
40 	struct acpi_osc_data *data;
41 
42 	list_for_each_entry(data, &acpi_osc_data_list, sibiling) {
43 		if (data->handle == handle)
44 			return data;
45 	}
46 	data = kzalloc(sizeof(*data), GFP_KERNEL);
47 	if (!data)
48 		return NULL;
49 	INIT_LIST_HEAD(&data->sibiling);
50 	data->handle = handle;
51 	list_add_tail(&data->sibiling, &acpi_osc_data_list);
52 	return data;
53 }
54 
55 static u8 OSC_UUID[16] = {0x5B, 0x4D, 0xDB, 0x33, 0xF7, 0x1F, 0x1C, 0x40,
56 			  0x96, 0x57, 0x74, 0x41, 0xC0, 0x3D, 0xD7, 0x66};
57 
58 static acpi_status acpi_run_osc(acpi_handle handle,
59 				struct acpi_osc_args *osc_args)
60 {
61 	acpi_status status;
62 	struct acpi_object_list input;
63 	union acpi_object in_params[4];
64 	struct acpi_buffer output = {ACPI_ALLOCATE_BUFFER, NULL};
65 	union acpi_object *out_obj;
66 	u32 osc_dw0, flags = osc_args->capbuf[OSC_QUERY_TYPE];
67 
68 	/* Setting up input parameters */
69 	input.count = 4;
70 	input.pointer = in_params;
71 	in_params[0].type 		= ACPI_TYPE_BUFFER;
72 	in_params[0].buffer.length 	= 16;
73 	in_params[0].buffer.pointer	= OSC_UUID;
74 	in_params[1].type 		= ACPI_TYPE_INTEGER;
75 	in_params[1].integer.value 	= 1;
76 	in_params[2].type 		= ACPI_TYPE_INTEGER;
77 	in_params[2].integer.value	= 3;
78 	in_params[3].type		= ACPI_TYPE_BUFFER;
79 	in_params[3].buffer.length 	= 12;
80 	in_params[3].buffer.pointer 	= (u8 *)osc_args->capbuf;
81 
82 	status = acpi_evaluate_object(handle, "_OSC", &input, &output);
83 	if (ACPI_FAILURE(status))
84 		return status;
85 
86 	out_obj = output.pointer;
87 	if (out_obj->type != ACPI_TYPE_BUFFER) {
88 		printk(KERN_DEBUG "Evaluate _OSC returns wrong type\n");
89 		status = AE_TYPE;
90 		goto out_kfree;
91 	}
92 	osc_dw0 = *((u32 *)out_obj->buffer.pointer);
93 	if (osc_dw0) {
94 		if (osc_dw0 & OSC_REQUEST_ERROR)
95 			printk(KERN_DEBUG "_OSC request fails\n");
96 		if (osc_dw0 & OSC_INVALID_UUID_ERROR)
97 			printk(KERN_DEBUG "_OSC invalid UUID\n");
98 		if (osc_dw0 & OSC_INVALID_REVISION_ERROR)
99 			printk(KERN_DEBUG "_OSC invalid revision\n");
100 		if (osc_dw0 & OSC_CAPABILITIES_MASK_ERROR) {
101 			if (flags & OSC_QUERY_ENABLE)
102 				goto out_success;
103 			printk(KERN_DEBUG "_OSC FW not grant req. control\n");
104 			status = AE_SUPPORT;
105 			goto out_kfree;
106 		}
107 		status = AE_ERROR;
108 		goto out_kfree;
109 	}
110 out_success:
111 	if (flags & OSC_QUERY_ENABLE)
112 		osc_args->query_result =
113 			*((u32 *)(out_obj->buffer.pointer + 8));
114 	status = AE_OK;
115 
116 out_kfree:
117 	kfree(output.pointer);
118 	return status;
119 }
120 
121 static acpi_status acpi_query_osc(acpi_handle handle,
122 				  u32 level, void *context, void **retval)
123 {
124 	acpi_status status;
125 	struct acpi_osc_data *osc_data;
126 	u32 flags = (unsigned long)context, support_set;
127 	acpi_handle tmp;
128 	struct acpi_osc_args osc_args;
129 
130 	status = acpi_get_handle(handle, "_OSC", &tmp);
131 	if (ACPI_FAILURE(status))
132 		return status;
133 
134 	osc_data = acpi_get_osc_data(handle);
135 	if (!osc_data) {
136 		printk(KERN_ERR "acpi osc data array is full\n");
137 		return AE_ERROR;
138 	}
139 
140 	/* do _OSC query for all possible controls */
141 	support_set = osc_data->support_set | (flags & OSC_SUPPORT_MASKS);
142 	osc_args.capbuf[OSC_QUERY_TYPE] = OSC_QUERY_ENABLE;
143 	osc_args.capbuf[OSC_SUPPORT_TYPE] = support_set;
144 	osc_args.capbuf[OSC_CONTROL_TYPE] = OSC_CONTROL_MASKS;
145 
146 	status = acpi_run_osc(handle, &osc_args);
147 	if (ACPI_SUCCESS(status)) {
148 		osc_data->support_set = support_set;
149 		osc_data->query_result = osc_args.query_result;
150 		osc_data->is_queried = 1;
151 	}
152 
153 	return status;
154 }
155 
156 /**
157  * __pci_osc_support_set - register OS support to Firmware
158  * @flags: OS support bits
159  * @hid: hardware ID
160  *
161  * Update OS support fields and doing a _OSC Query to obtain an update
162  * from Firmware on supported control bits.
163  **/
164 acpi_status __pci_osc_support_set(u32 flags, const char *hid)
165 {
166 	if (!(flags & OSC_SUPPORT_MASKS))
167 		return AE_TYPE;
168 
169 	acpi_get_devices(hid, acpi_query_osc,
170 			 (void *)(unsigned long)flags, NULL);
171 	return AE_OK;
172 }
173 
174 /**
175  * pci_osc_control_set - commit requested control to Firmware
176  * @handle: acpi_handle for the target ACPI object
177  * @flags: driver's requested control bits
178  *
179  * Attempt to take control from Firmware on requested control bits.
180  **/
181 acpi_status pci_osc_control_set(acpi_handle handle, u32 flags)
182 {
183 	acpi_status status;
184 	u32 ctrlset, control_set;
185 	acpi_handle tmp;
186 	struct acpi_osc_data *osc_data;
187 	struct acpi_osc_args osc_args;
188 
189 	status = acpi_get_handle(handle, "_OSC", &tmp);
190 	if (ACPI_FAILURE(status))
191 		return status;
192 
193 	osc_data = acpi_get_osc_data(handle);
194 	if (!osc_data) {
195 		printk(KERN_ERR "acpi osc data array is full\n");
196 		return AE_ERROR;
197 	}
198 
199 	ctrlset = (flags & OSC_CONTROL_MASKS);
200 	if (!ctrlset)
201 		return AE_TYPE;
202 
203 	if (osc_data->is_queried &&
204 	    ((osc_data->query_result & ctrlset) != ctrlset))
205 		return AE_SUPPORT;
206 
207 	control_set = osc_data->control_set | ctrlset;
208 	osc_args.capbuf[OSC_QUERY_TYPE] = 0;
209 	osc_args.capbuf[OSC_SUPPORT_TYPE] = osc_data->support_set;
210 	osc_args.capbuf[OSC_CONTROL_TYPE] = control_set;
211 	status = acpi_run_osc(handle, &osc_args);
212 	if (ACPI_SUCCESS(status))
213 		osc_data->control_set = control_set;
214 
215 	return status;
216 }
217 EXPORT_SYMBOL(pci_osc_control_set);
218 
219 /*
220  * _SxD returns the D-state with the highest power
221  * (lowest D-state number) supported in the S-state "x".
222  *
223  * If the devices does not have a _PRW
224  * (Power Resources for Wake) supporting system wakeup from "x"
225  * then the OS is free to choose a lower power (higher number
226  * D-state) than the return value from _SxD.
227  *
228  * But if _PRW is enabled at S-state "x", the OS
229  * must not choose a power lower than _SxD --
230  * unless the device has an _SxW method specifying
231  * the lowest power (highest D-state number) the device
232  * may enter while still able to wake the system.
233  *
234  * ie. depending on global OS policy:
235  *
236  * if (_PRW at S-state x)
237  *	choose from highest power _SxD to lowest power _SxW
238  * else // no _PRW at S-state x
239  * 	choose highest power _SxD or any lower power
240  */
241 
242 static pci_power_t acpi_pci_choose_state(struct pci_dev *pdev)
243 {
244 	int acpi_state;
245 
246 	acpi_state = acpi_pm_device_sleep_state(&pdev->dev, NULL);
247 	if (acpi_state < 0)
248 		return PCI_POWER_ERROR;
249 
250 	switch (acpi_state) {
251 	case ACPI_STATE_D0:
252 		return PCI_D0;
253 	case ACPI_STATE_D1:
254 		return PCI_D1;
255 	case ACPI_STATE_D2:
256 		return PCI_D2;
257 	case ACPI_STATE_D3:
258 		return PCI_D3hot;
259 	}
260 	return PCI_POWER_ERROR;
261 }
262 
263 static bool acpi_pci_power_manageable(struct pci_dev *dev)
264 {
265 	acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
266 
267 	return handle ? acpi_bus_power_manageable(handle) : false;
268 }
269 
270 static int acpi_pci_set_power_state(struct pci_dev *dev, pci_power_t state)
271 {
272 	acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
273 	acpi_handle tmp;
274 	static const u8 state_conv[] = {
275 		[PCI_D0] = ACPI_STATE_D0,
276 		[PCI_D1] = ACPI_STATE_D1,
277 		[PCI_D2] = ACPI_STATE_D2,
278 		[PCI_D3hot] = ACPI_STATE_D3,
279 		[PCI_D3cold] = ACPI_STATE_D3
280 	};
281 	int error = -EINVAL;
282 
283 	/* If the ACPI device has _EJ0, ignore the device */
284 	if (!handle || ACPI_SUCCESS(acpi_get_handle(handle, "_EJ0", &tmp)))
285 		return -ENODEV;
286 
287 	switch (state) {
288 	case PCI_D0:
289 	case PCI_D1:
290 	case PCI_D2:
291 	case PCI_D3hot:
292 	case PCI_D3cold:
293 		error = acpi_bus_set_power(handle, state_conv[state]);
294 	}
295 
296 	if (!error)
297 		dev_printk(KERN_INFO, &dev->dev,
298 				"power state changed by ACPI to D%d\n", state);
299 
300 	return error;
301 }
302 
303 static bool acpi_pci_can_wakeup(struct pci_dev *dev)
304 {
305 	acpi_handle handle = DEVICE_ACPI_HANDLE(&dev->dev);
306 
307 	return handle ? acpi_bus_can_wakeup(handle) : false;
308 }
309 
310 static int acpi_pci_sleep_wake(struct pci_dev *dev, bool enable)
311 {
312 	int error = acpi_pm_device_sleep_wake(&dev->dev, enable);
313 
314 	if (!error)
315 		dev_printk(KERN_INFO, &dev->dev,
316 				"wake-up capability %s by ACPI\n",
317 				enable ? "enabled" : "disabled");
318 	return error;
319 }
320 
321 static struct pci_platform_pm_ops acpi_pci_platform_pm = {
322 	.is_manageable = acpi_pci_power_manageable,
323 	.set_state = acpi_pci_set_power_state,
324 	.choose_state = acpi_pci_choose_state,
325 	.can_wakeup = acpi_pci_can_wakeup,
326 	.sleep_wake = acpi_pci_sleep_wake,
327 };
328 
329 /* ACPI bus type */
330 static int acpi_pci_find_device(struct device *dev, acpi_handle *handle)
331 {
332 	struct pci_dev * pci_dev;
333 	acpi_integer	addr;
334 
335 	pci_dev = to_pci_dev(dev);
336 	/* Please ref to ACPI spec for the syntax of _ADR */
337 	addr = (PCI_SLOT(pci_dev->devfn) << 16) | PCI_FUNC(pci_dev->devfn);
338 	*handle = acpi_get_child(DEVICE_ACPI_HANDLE(dev->parent), addr);
339 	if (!*handle)
340 		return -ENODEV;
341 	return 0;
342 }
343 
344 static int acpi_pci_find_root_bridge(struct device *dev, acpi_handle *handle)
345 {
346 	int num;
347 	unsigned int seg, bus;
348 
349 	/*
350 	 * The string should be the same as root bridge's name
351 	 * Please look at 'pci_scan_bus_parented'
352 	 */
353 	num = sscanf(dev->bus_id, "pci%04x:%02x", &seg, &bus);
354 	if (num != 2)
355 		return -ENODEV;
356 	*handle = acpi_get_pci_rootbridge_handle(seg, bus);
357 	if (!*handle)
358 		return -ENODEV;
359 	return 0;
360 }
361 
362 static struct acpi_bus_type acpi_pci_bus = {
363 	.bus = &pci_bus_type,
364 	.find_device = acpi_pci_find_device,
365 	.find_bridge = acpi_pci_find_root_bridge,
366 };
367 
368 static int __init acpi_pci_init(void)
369 {
370 	int ret;
371 
372 	if (acpi_gbl_FADT.boot_flags & BAF_MSI_NOT_SUPPORTED) {
373 		printk(KERN_INFO"ACPI FADT declares the system doesn't support MSI, so disable it\n");
374 		pci_no_msi();
375 	}
376 
377 	if (acpi_gbl_FADT.boot_flags & BAF_PCIE_ASPM_CONTROL) {
378 		printk(KERN_INFO"ACPI FADT declares the system doesn't support PCIe ASPM, so disable it\n");
379 		pcie_no_aspm();
380 	}
381 
382 	ret = register_acpi_bus_type(&acpi_pci_bus);
383 	if (ret)
384 		return 0;
385 	pci_set_platform_pm(&acpi_pci_platform_pm);
386 	return 0;
387 }
388 arch_initcall(acpi_pci_init);
389