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v3.1
  1/*
  2 * Shared support code for AMD K8 northbridges and derivates.
  3 * Copyright 2006 Andi Kleen, SUSE Labs. Subject to GPLv2.
  4 */
 
 
 
  5#include <linux/types.h>
  6#include <linux/slab.h>
  7#include <linux/init.h>
  8#include <linux/errno.h>
  9#include <linux/module.h>
 10#include <linux/spinlock.h>
 11#include <asm/amd_nb.h>
 12
 
 
 
 
 
 
 
 13static u32 *flush_words;
 14
 
 
 
 
 
 15const struct pci_device_id amd_nb_misc_ids[] = {
 16	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_K8_NB_MISC) },
 17	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_10H_NB_MISC) },
 18	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_NB_F3) },
 
 
 
 
 
 
 19	{}
 20};
 21EXPORT_SYMBOL(amd_nb_misc_ids);
 22
 23static struct pci_device_id amd_nb_link_ids[] = {
 24	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_NB_F4) },
 
 
 
 
 
 25	{}
 26};
 27
 28const struct amd_nb_bus_dev_range amd_nb_bus_dev_ranges[] __initconst = {
 29	{ 0x00, 0x18, 0x20 },
 30	{ 0xff, 0x00, 0x20 },
 31	{ 0xfe, 0x00, 0x20 },
 32	{ }
 33};
 34
 35struct amd_northbridge_info amd_northbridges;
 36EXPORT_SYMBOL(amd_northbridges);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 37
 38static struct pci_dev *next_northbridge(struct pci_dev *dev,
 39					const struct pci_device_id *ids)
 40{
 41	do {
 42		dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev);
 43		if (!dev)
 44			break;
 45	} while (!pci_match_id(ids, dev));
 46	return dev;
 47}
 48
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 49int amd_cache_northbridges(void)
 50{
 51	u16 i = 0;
 52	struct amd_northbridge *nb;
 53	struct pci_dev *misc, *link;
 54
 55	if (amd_nb_num())
 56		return 0;
 57
 58	misc = NULL;
 59	while ((misc = next_northbridge(misc, amd_nb_misc_ids)) != NULL)
 60		i++;
 61
 62	if (i == 0)
 63		return 0;
 64
 65	nb = kzalloc(i * sizeof(struct amd_northbridge), GFP_KERNEL);
 66	if (!nb)
 67		return -ENOMEM;
 68
 69	amd_northbridges.nb = nb;
 70	amd_northbridges.num = i;
 71
 72	link = misc = NULL;
 73	for (i = 0; i != amd_nb_num(); i++) {
 
 
 74		node_to_amd_nb(i)->misc = misc =
 75			next_northbridge(misc, amd_nb_misc_ids);
 76		node_to_amd_nb(i)->link = link =
 77			next_northbridge(link, amd_nb_link_ids);
 78        }
 79
 80	/* some CPU families (e.g. family 0x11) do not support GART */
 81	if (boot_cpu_data.x86 == 0xf || boot_cpu_data.x86 == 0x10 ||
 82	    boot_cpu_data.x86 == 0x15)
 83		amd_northbridges.flags |= AMD_NB_GART;
 84
 85	/*
 
 
 
 
 
 
 86	 * Some CPU families support L3 Cache Index Disable. There are some
 87	 * limitations because of E382 and E388 on family 0x10.
 88	 */
 89	if (boot_cpu_data.x86 == 0x10 &&
 90	    boot_cpu_data.x86_model >= 0x8 &&
 91	    (boot_cpu_data.x86_model > 0x9 ||
 92	     boot_cpu_data.x86_mask >= 0x1))
 93		amd_northbridges.flags |= AMD_NB_L3_INDEX_DISABLE;
 94
 95	if (boot_cpu_data.x86 == 0x15)
 96		amd_northbridges.flags |= AMD_NB_L3_INDEX_DISABLE;
 97
 98	/* L3 cache partitioning is supported on family 0x15 */
 99	if (boot_cpu_data.x86 == 0x15)
100		amd_northbridges.flags |= AMD_NB_L3_PARTITIONING;
101
102	return 0;
103}
104EXPORT_SYMBOL_GPL(amd_cache_northbridges);
105
106/*
107 * Ignores subdevice/subvendor but as far as I can figure out
108 * they're useless anyways
109 */
110bool __init early_is_amd_nb(u32 device)
111{
112	const struct pci_device_id *id;
113	u32 vendor = device & 0xffff;
114
115	device >>= 16;
116	for (id = amd_nb_misc_ids; id->vendor; id++)
117		if (vendor == id->vendor && device == id->device)
118			return true;
119	return false;
120}
121
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
122int amd_get_subcaches(int cpu)
123{
124	struct pci_dev *link = node_to_amd_nb(amd_get_nb_id(cpu))->link;
125	unsigned int mask;
126	int cuid = 0;
127
128	if (!amd_nb_has_feature(AMD_NB_L3_PARTITIONING))
129		return 0;
130
131	pci_read_config_dword(link, 0x1d4, &mask);
132
133#ifdef CONFIG_SMP
134	cuid = cpu_data(cpu).compute_unit_id;
135#endif
136	return (mask >> (4 * cuid)) & 0xf;
137}
138
139int amd_set_subcaches(int cpu, int mask)
140{
141	static unsigned int reset, ban;
142	struct amd_northbridge *nb = node_to_amd_nb(amd_get_nb_id(cpu));
143	unsigned int reg;
144	int cuid = 0;
145
146	if (!amd_nb_has_feature(AMD_NB_L3_PARTITIONING) || mask > 0xf)
147		return -EINVAL;
148
149	/* if necessary, collect reset state of L3 partitioning and BAN mode */
150	if (reset == 0) {
151		pci_read_config_dword(nb->link, 0x1d4, &reset);
152		pci_read_config_dword(nb->misc, 0x1b8, &ban);
153		ban &= 0x180000;
154	}
155
156	/* deactivate BAN mode if any subcaches are to be disabled */
157	if (mask != 0xf) {
158		pci_read_config_dword(nb->misc, 0x1b8, &reg);
159		pci_write_config_dword(nb->misc, 0x1b8, reg & ~0x180000);
160	}
161
162#ifdef CONFIG_SMP
163	cuid = cpu_data(cpu).compute_unit_id;
164#endif
165	mask <<= 4 * cuid;
166	mask |= (0xf ^ (1 << cuid)) << 26;
167
168	pci_write_config_dword(nb->link, 0x1d4, mask);
169
170	/* reset BAN mode if L3 partitioning returned to reset state */
171	pci_read_config_dword(nb->link, 0x1d4, &reg);
172	if (reg == reset) {
173		pci_read_config_dword(nb->misc, 0x1b8, &reg);
174		reg &= ~0x180000;
175		pci_write_config_dword(nb->misc, 0x1b8, reg | ban);
176	}
177
178	return 0;
179}
180
181static int amd_cache_gart(void)
182{
183	u16 i;
184
185       if (!amd_nb_has_feature(AMD_NB_GART))
186               return 0;
187
188       flush_words = kmalloc(amd_nb_num() * sizeof(u32), GFP_KERNEL);
189       if (!flush_words) {
190               amd_northbridges.flags &= ~AMD_NB_GART;
191               return -ENOMEM;
192       }
193
194       for (i = 0; i != amd_nb_num(); i++)
195               pci_read_config_dword(node_to_amd_nb(i)->misc, 0x9c,
196                                     &flush_words[i]);
197
198       return 0;
 
199}
200
201void amd_flush_garts(void)
202{
203	int flushed, i;
204	unsigned long flags;
205	static DEFINE_SPINLOCK(gart_lock);
206
207	if (!amd_nb_has_feature(AMD_NB_GART))
208		return;
209
210	/* Avoid races between AGP and IOMMU. In theory it's not needed
211	   but I'm not sure if the hardware won't lose flush requests
212	   when another is pending. This whole thing is so expensive anyways
213	   that it doesn't matter to serialize more. -AK */
 
 
214	spin_lock_irqsave(&gart_lock, flags);
215	flushed = 0;
216	for (i = 0; i < amd_nb_num(); i++) {
217		pci_write_config_dword(node_to_amd_nb(i)->misc, 0x9c,
218				       flush_words[i] | 1);
219		flushed++;
220	}
221	for (i = 0; i < amd_nb_num(); i++) {
222		u32 w;
223		/* Make sure the hardware actually executed the flush*/
224		for (;;) {
225			pci_read_config_dword(node_to_amd_nb(i)->misc,
226					      0x9c, &w);
227			if (!(w & 1))
228				break;
229			cpu_relax();
230		}
231	}
232	spin_unlock_irqrestore(&gart_lock, flags);
233	if (!flushed)
234		printk("nothing to flush?\n");
235}
236EXPORT_SYMBOL_GPL(amd_flush_garts);
237
238static __init int init_amd_nbs(void)
239{
240	int err = 0;
241
242	err = amd_cache_northbridges();
243
244	if (err < 0)
245		printk(KERN_NOTICE "AMD NB: Cannot enumerate AMD northbridges.\n");
246
247	if (amd_cache_gart() < 0)
248		printk(KERN_NOTICE "AMD NB: Cannot initialize GART flush words, "
249		       "GART support disabled.\n");
250
251	return err;
252}
253
254/* This has to go after the PCI subsystem */
255fs_initcall(init_amd_nbs);
v4.10.11
  1/*
  2 * Shared support code for AMD K8 northbridges and derivates.
  3 * Copyright 2006 Andi Kleen, SUSE Labs. Subject to GPLv2.
  4 */
  5
  6#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  7
  8#include <linux/types.h>
  9#include <linux/slab.h>
 10#include <linux/init.h>
 11#include <linux/errno.h>
 12#include <linux/export.h>
 13#include <linux/spinlock.h>
 14#include <asm/amd_nb.h>
 15
 16#define PCI_DEVICE_ID_AMD_17H_ROOT	0x1450
 17#define PCI_DEVICE_ID_AMD_17H_DF_F3	0x1463
 18#define PCI_DEVICE_ID_AMD_17H_DF_F4	0x1464
 19
 20/* Protect the PCI config register pairs used for SMN and DF indirect access. */
 21static DEFINE_MUTEX(smn_mutex);
 22
 23static u32 *flush_words;
 24
 25static const struct pci_device_id amd_root_ids[] = {
 26	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_ROOT) },
 27	{}
 28};
 29
 30const struct pci_device_id amd_nb_misc_ids[] = {
 31	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_K8_NB_MISC) },
 32	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_10H_NB_MISC) },
 33	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_NB_F3) },
 34	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_M10H_F3) },
 35	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_M30H_NB_F3) },
 36	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_M60H_NB_F3) },
 37	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_NB_F3) },
 38	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_M30H_NB_F3) },
 39	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_DF_F3) },
 40	{}
 41};
 42EXPORT_SYMBOL_GPL(amd_nb_misc_ids);
 43
 44static const struct pci_device_id amd_nb_link_ids[] = {
 45	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_NB_F4) },
 46	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_M30H_NB_F4) },
 47	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_15H_M60H_NB_F4) },
 48	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_NB_F4) },
 49	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_16H_M30H_NB_F4) },
 50	{ PCI_DEVICE(PCI_VENDOR_ID_AMD, PCI_DEVICE_ID_AMD_17H_DF_F4) },
 51	{}
 52};
 53
 54const struct amd_nb_bus_dev_range amd_nb_bus_dev_ranges[] __initconst = {
 55	{ 0x00, 0x18, 0x20 },
 56	{ 0xff, 0x00, 0x20 },
 57	{ 0xfe, 0x00, 0x20 },
 58	{ }
 59};
 60
 61static struct amd_northbridge_info amd_northbridges;
 62
 63u16 amd_nb_num(void)
 64{
 65	return amd_northbridges.num;
 66}
 67EXPORT_SYMBOL_GPL(amd_nb_num);
 68
 69bool amd_nb_has_feature(unsigned int feature)
 70{
 71	return ((amd_northbridges.flags & feature) == feature);
 72}
 73EXPORT_SYMBOL_GPL(amd_nb_has_feature);
 74
 75struct amd_northbridge *node_to_amd_nb(int node)
 76{
 77	return (node < amd_northbridges.num) ? &amd_northbridges.nb[node] : NULL;
 78}
 79EXPORT_SYMBOL_GPL(node_to_amd_nb);
 80
 81static struct pci_dev *next_northbridge(struct pci_dev *dev,
 82					const struct pci_device_id *ids)
 83{
 84	do {
 85		dev = pci_get_device(PCI_ANY_ID, PCI_ANY_ID, dev);
 86		if (!dev)
 87			break;
 88	} while (!pci_match_id(ids, dev));
 89	return dev;
 90}
 91
 92static int __amd_smn_rw(u16 node, u32 address, u32 *value, bool write)
 93{
 94	struct pci_dev *root;
 95	int err = -ENODEV;
 96
 97	if (node >= amd_northbridges.num)
 98		goto out;
 99
100	root = node_to_amd_nb(node)->root;
101	if (!root)
102		goto out;
103
104	mutex_lock(&smn_mutex);
105
106	err = pci_write_config_dword(root, 0x60, address);
107	if (err) {
108		pr_warn("Error programming SMN address 0x%x.\n", address);
109		goto out_unlock;
110	}
111
112	err = (write ? pci_write_config_dword(root, 0x64, *value)
113		     : pci_read_config_dword(root, 0x64, value));
114	if (err)
115		pr_warn("Error %s SMN address 0x%x.\n",
116			(write ? "writing to" : "reading from"), address);
117
118out_unlock:
119	mutex_unlock(&smn_mutex);
120
121out:
122	return err;
123}
124
125int amd_smn_read(u16 node, u32 address, u32 *value)
126{
127	return __amd_smn_rw(node, address, value, false);
128}
129EXPORT_SYMBOL_GPL(amd_smn_read);
130
131int amd_smn_write(u16 node, u32 address, u32 value)
132{
133	return __amd_smn_rw(node, address, &value, true);
134}
135EXPORT_SYMBOL_GPL(amd_smn_write);
136
137/*
138 * Data Fabric Indirect Access uses FICAA/FICAD.
139 *
140 * Fabric Indirect Configuration Access Address (FICAA): Constructed based
141 * on the device's Instance Id and the PCI function and register offset of
142 * the desired register.
143 *
144 * Fabric Indirect Configuration Access Data (FICAD): There are FICAD LO
145 * and FICAD HI registers but so far we only need the LO register.
146 */
147int amd_df_indirect_read(u16 node, u8 func, u16 reg, u8 instance_id, u32 *lo)
148{
149	struct pci_dev *F4;
150	u32 ficaa;
151	int err = -ENODEV;
152
153	if (node >= amd_northbridges.num)
154		goto out;
155
156	F4 = node_to_amd_nb(node)->link;
157	if (!F4)
158		goto out;
159
160	ficaa  = 1;
161	ficaa |= reg & 0x3FC;
162	ficaa |= (func & 0x7) << 11;
163	ficaa |= instance_id << 16;
164
165	mutex_lock(&smn_mutex);
166
167	err = pci_write_config_dword(F4, 0x5C, ficaa);
168	if (err) {
169		pr_warn("Error writing DF Indirect FICAA, FICAA=0x%x\n", ficaa);
170		goto out_unlock;
171	}
172
173	err = pci_read_config_dword(F4, 0x98, lo);
174	if (err)
175		pr_warn("Error reading DF Indirect FICAD LO, FICAA=0x%x.\n", ficaa);
176
177out_unlock:
178	mutex_unlock(&smn_mutex);
179
180out:
181	return err;
182}
183EXPORT_SYMBOL_GPL(amd_df_indirect_read);
184
185int amd_cache_northbridges(void)
186{
187	u16 i = 0;
188	struct amd_northbridge *nb;
189	struct pci_dev *root, *misc, *link;
190
191	if (amd_northbridges.num)
192		return 0;
193
194	misc = NULL;
195	while ((misc = next_northbridge(misc, amd_nb_misc_ids)) != NULL)
196		i++;
197
198	if (!i)
199		return -ENODEV;
200
201	nb = kcalloc(i, sizeof(struct amd_northbridge), GFP_KERNEL);
202	if (!nb)
203		return -ENOMEM;
204
205	amd_northbridges.nb = nb;
206	amd_northbridges.num = i;
207
208	link = misc = root = NULL;
209	for (i = 0; i != amd_northbridges.num; i++) {
210		node_to_amd_nb(i)->root = root =
211			next_northbridge(root, amd_root_ids);
212		node_to_amd_nb(i)->misc = misc =
213			next_northbridge(misc, amd_nb_misc_ids);
214		node_to_amd_nb(i)->link = link =
215			next_northbridge(link, amd_nb_link_ids);
216	}
217
218	if (amd_gart_present())
 
 
219		amd_northbridges.flags |= AMD_NB_GART;
220
221	/*
222	 * Check for L3 cache presence.
223	 */
224	if (!cpuid_edx(0x80000006))
225		return 0;
226
227	/*
228	 * Some CPU families support L3 Cache Index Disable. There are some
229	 * limitations because of E382 and E388 on family 0x10.
230	 */
231	if (boot_cpu_data.x86 == 0x10 &&
232	    boot_cpu_data.x86_model >= 0x8 &&
233	    (boot_cpu_data.x86_model > 0x9 ||
234	     boot_cpu_data.x86_mask >= 0x1))
235		amd_northbridges.flags |= AMD_NB_L3_INDEX_DISABLE;
236
237	if (boot_cpu_data.x86 == 0x15)
238		amd_northbridges.flags |= AMD_NB_L3_INDEX_DISABLE;
239
240	/* L3 cache partitioning is supported on family 0x15 */
241	if (boot_cpu_data.x86 == 0x15)
242		amd_northbridges.flags |= AMD_NB_L3_PARTITIONING;
243
244	return 0;
245}
246EXPORT_SYMBOL_GPL(amd_cache_northbridges);
247
248/*
249 * Ignores subdevice/subvendor but as far as I can figure out
250 * they're useless anyways
251 */
252bool __init early_is_amd_nb(u32 device)
253{
254	const struct pci_device_id *id;
255	u32 vendor = device & 0xffff;
256
257	device >>= 16;
258	for (id = amd_nb_misc_ids; id->vendor; id++)
259		if (vendor == id->vendor && device == id->device)
260			return true;
261	return false;
262}
263
264struct resource *amd_get_mmconfig_range(struct resource *res)
265{
266	u32 address;
267	u64 base, msr;
268	unsigned int segn_busn_bits;
269
270	if (boot_cpu_data.x86_vendor != X86_VENDOR_AMD)
271		return NULL;
272
273	/* assume all cpus from fam10h have mmconfig */
274	if (boot_cpu_data.x86 < 0x10)
275		return NULL;
276
277	address = MSR_FAM10H_MMIO_CONF_BASE;
278	rdmsrl(address, msr);
279
280	/* mmconfig is not enabled */
281	if (!(msr & FAM10H_MMIO_CONF_ENABLE))
282		return NULL;
283
284	base = msr & (FAM10H_MMIO_CONF_BASE_MASK<<FAM10H_MMIO_CONF_BASE_SHIFT);
285
286	segn_busn_bits = (msr >> FAM10H_MMIO_CONF_BUSRANGE_SHIFT) &
287			 FAM10H_MMIO_CONF_BUSRANGE_MASK;
288
289	res->flags = IORESOURCE_MEM;
290	res->start = base;
291	res->end = base + (1ULL<<(segn_busn_bits + 20)) - 1;
292	return res;
293}
294
295int amd_get_subcaches(int cpu)
296{
297	struct pci_dev *link = node_to_amd_nb(amd_get_nb_id(cpu))->link;
298	unsigned int mask;
 
299
300	if (!amd_nb_has_feature(AMD_NB_L3_PARTITIONING))
301		return 0;
302
303	pci_read_config_dword(link, 0x1d4, &mask);
304
305	return (mask >> (4 * cpu_data(cpu).cpu_core_id)) & 0xf;
 
 
 
306}
307
308int amd_set_subcaches(int cpu, unsigned long mask)
309{
310	static unsigned int reset, ban;
311	struct amd_northbridge *nb = node_to_amd_nb(amd_get_nb_id(cpu));
312	unsigned int reg;
313	int cuid;
314
315	if (!amd_nb_has_feature(AMD_NB_L3_PARTITIONING) || mask > 0xf)
316		return -EINVAL;
317
318	/* if necessary, collect reset state of L3 partitioning and BAN mode */
319	if (reset == 0) {
320		pci_read_config_dword(nb->link, 0x1d4, &reset);
321		pci_read_config_dword(nb->misc, 0x1b8, &ban);
322		ban &= 0x180000;
323	}
324
325	/* deactivate BAN mode if any subcaches are to be disabled */
326	if (mask != 0xf) {
327		pci_read_config_dword(nb->misc, 0x1b8, &reg);
328		pci_write_config_dword(nb->misc, 0x1b8, reg & ~0x180000);
329	}
330
331	cuid = cpu_data(cpu).cpu_core_id;
 
 
332	mask <<= 4 * cuid;
333	mask |= (0xf ^ (1 << cuid)) << 26;
334
335	pci_write_config_dword(nb->link, 0x1d4, mask);
336
337	/* reset BAN mode if L3 partitioning returned to reset state */
338	pci_read_config_dword(nb->link, 0x1d4, &reg);
339	if (reg == reset) {
340		pci_read_config_dword(nb->misc, 0x1b8, &reg);
341		reg &= ~0x180000;
342		pci_write_config_dword(nb->misc, 0x1b8, reg | ban);
343	}
344
345	return 0;
346}
347
348static void amd_cache_gart(void)
349{
350	u16 i;
351
352	if (!amd_nb_has_feature(AMD_NB_GART))
353		return;
354
355	flush_words = kmalloc_array(amd_northbridges.num, sizeof(u32), GFP_KERNEL);
356	if (!flush_words) {
357		amd_northbridges.flags &= ~AMD_NB_GART;
358		pr_notice("Cannot initialize GART flush words, GART support disabled\n");
359		return;
360	}
 
 
 
361
362	for (i = 0; i != amd_northbridges.num; i++)
363		pci_read_config_dword(node_to_amd_nb(i)->misc, 0x9c, &flush_words[i]);
364}
365
366void amd_flush_garts(void)
367{
368	int flushed, i;
369	unsigned long flags;
370	static DEFINE_SPINLOCK(gart_lock);
371
372	if (!amd_nb_has_feature(AMD_NB_GART))
373		return;
374
375	/*
376	 * Avoid races between AGP and IOMMU. In theory it's not needed
377	 * but I'm not sure if the hardware won't lose flush requests
378	 * when another is pending. This whole thing is so expensive anyways
379	 * that it doesn't matter to serialize more. -AK
380	 */
381	spin_lock_irqsave(&gart_lock, flags);
382	flushed = 0;
383	for (i = 0; i < amd_northbridges.num; i++) {
384		pci_write_config_dword(node_to_amd_nb(i)->misc, 0x9c,
385				       flush_words[i] | 1);
386		flushed++;
387	}
388	for (i = 0; i < amd_northbridges.num; i++) {
389		u32 w;
390		/* Make sure the hardware actually executed the flush*/
391		for (;;) {
392			pci_read_config_dword(node_to_amd_nb(i)->misc,
393					      0x9c, &w);
394			if (!(w & 1))
395				break;
396			cpu_relax();
397		}
398	}
399	spin_unlock_irqrestore(&gart_lock, flags);
400	if (!flushed)
401		pr_notice("nothing to flush?\n");
402}
403EXPORT_SYMBOL_GPL(amd_flush_garts);
404
405static __init int init_amd_nbs(void)
406{
407	amd_cache_northbridges();
408	amd_cache_gart();
 
409
410	return 0;
 
 
 
 
 
 
 
411}
412
413/* This has to go after the PCI subsystem */
414fs_initcall(init_amd_nbs);