dca: registering requesters in multiple dca domains

This patch enables DCA support on multiple-IOH/multiple-IIO architectures. It modifies dca module by replacing single dca_providers list with dca_domains list, each domain containing separate list of providers. This approach lets dca driver manage multiple domains, i.e. sets of providers and requesters mapped back to the same PCI root complex device. The driver takes care to register each requester to a provider from the same domain. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com>

dca: registering requesters in multiple dca domains
This patch enables DCA support on multiple-IOH/multiple-IIO architectures. It modifies dca module by replacing single dca_providers list with dca_domains list, each domain containing separate list of providers. This approach lets dca driver manage multiple domains, i.e. sets of providers and requesters mapped back to the same PCI root complex device. The driver takes care to register each requester to a provider from the same domain. Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Maciej Sosnowski <maciej.sosnowski@intel.com>
Maciej Sosnowski · Dan Williams
1 parent 9a8de639f3
Showing 3 changed files with 120 additions and 15 deletions Side-by-side Diff
drivers/dca/dca-core.c
drivers/dma/ioat/pci.c
include/linux/dca.h
@@ -28,7 +28,7 @@
 #include <linux/device.h>
 #include <linux/dca.h>
  
-#define DCA_VERSION "1.8"
+#define DCA_VERSION "1.12.1"
  
 MODULE_VERSION(DCA_VERSION);
 MODULE_LICENSE("GPL");
  
  
  
  
@@ -36,20 +36,92 @@
  
 static DEFINE_SPINLOCK(dca_lock);
  
-static LIST_HEAD(dca_providers);
+static LIST_HEAD(dca_domains);
  
+static struct pci_bus *dca_pci_rc_from_dev(struct device *dev)
+{
+	struct pci_dev *pdev = to_pci_dev(dev);
+	struct pci_bus *bus = pdev->bus;
+
+	while (bus->parent)
+		bus = bus->parent;
+
+	return bus;
+}
+
+static struct dca_domain *dca_allocate_domain(struct pci_bus *rc)
+{
+	struct dca_domain *domain;
+
+	domain = kzalloc(sizeof(*domain), GFP_NOWAIT);
+	if (!domain)
+		return NULL;
+
+	INIT_LIST_HEAD(&domain->dca_providers);
+	domain->pci_rc = rc;
+
+	return domain;
+}
+
+static void dca_free_domain(struct dca_domain *domain)
+{
+	list_del(&domain->node);
+	kfree(domain);
+}
+
+static struct dca_domain *dca_find_domain(struct pci_bus *rc)
+{
+	struct dca_domain *domain;
+
+	list_for_each_entry(domain, &dca_domains, node)
+		if (domain->pci_rc == rc)
+			return domain;
+
+	return NULL;
+}
+
+static struct dca_domain *dca_get_domain(struct device *dev)
+{
+	struct pci_bus *rc;
+	struct dca_domain *domain;
+
+	rc = dca_pci_rc_from_dev(dev);
+	domain = dca_find_domain(rc);
+
+	if (!domain) {
+		domain = dca_allocate_domain(rc);
+		if (domain)
+			list_add(&domain->node, &dca_domains);
+	}
+
+	return domain;
+}
+
 static struct dca_provider *dca_find_provider_by_dev(struct device *dev)
 {
-	struct dca_provider *dca, *ret = NULL;
+	struct dca_provider *dca;
+	struct pci_bus *rc;
+	struct dca_domain *domain;
  
-	list_for_each_entry(dca, &dca_providers, node) {
-		if ((!dev) || (dca->ops->dev_managed(dca, dev))) {
-			ret = dca;
-			break;
-		}
+	if (dev) {
+		rc = dca_pci_rc_from_dev(dev);
+		domain = dca_find_domain(rc);
+		if (!domain)
+			return NULL;
+	} else {
+		if (!list_empty(&dca_domains))
+			domain = list_first_entry(&dca_domains,
+						  struct dca_domain,
+						  node);
+		else
+			return NULL;
 	}
  
-	return ret;
+	list_for_each_entry(dca, &domain->dca_providers, node)
+		if ((!dev) || (dca->ops->dev_managed(dca, dev)))
+			return dca;
+
+	return NULL;
 }
  
 /**
@@ -61,6 +133,8 @@
 	struct dca_provider *dca;
 	int err, slot = -ENODEV;
 	unsigned long flags;
+	struct pci_bus *pci_rc;
+	struct dca_domain *domain;
  
 	if (!dev)
 		return -EFAULT;
@@ -74,7 +148,14 @@
 		return -EEXIST;
 	}
  
-	list_for_each_entry(dca, &dca_providers, node) {
+	pci_rc = dca_pci_rc_from_dev(dev);
+	domain = dca_find_domain(pci_rc);
+	if (!domain) {
+		spin_unlock_irqrestore(&dca_lock, flags);
+		return -ENODEV;
+	}
+
+	list_for_each_entry(dca, &domain->dca_providers, node) {
 		slot = dca->ops->add_requester(dca, dev);
 		if (slot >= 0)
 			break;
  
@@ -222,13 +303,19 @@
 {
 	int err;
 	unsigned long flags;
+	struct dca_domain *domain;
  
 	err = dca_sysfs_add_provider(dca, dev);
 	if (err)
 		return err;
  
 	spin_lock_irqsave(&dca_lock, flags);
-	list_add(&dca->node, &dca_providers);
+	domain = dca_get_domain(dev);
+	if (!domain) {
+		spin_unlock_irqrestore(&dca_lock, flags);
+		return -ENODEV;
+	}
+	list_add(&dca->node, &domain->dca_providers);
 	spin_unlock_irqrestore(&dca_lock, flags);
  
 	blocking_notifier_call_chain(&dca_provider_chain,
  
  
  
@@ -241,15 +328,24 @@
  * unregister_dca_provider - remove a dca provider
  * @dca - struct created by alloc_dca_provider()
  */
-void unregister_dca_provider(struct dca_provider *dca)
+void unregister_dca_provider(struct dca_provider *dca, struct device *dev)
 {
 	unsigned long flags;
+	struct pci_bus *pci_rc;
+	struct dca_domain *domain;
  
 	blocking_notifier_call_chain(&dca_provider_chain,
 				     DCA_PROVIDER_REMOVE, NULL);
  
 	spin_lock_irqsave(&dca_lock, flags);
+
 	list_del(&dca->node);
+
+	pci_rc = dca_pci_rc_from_dev(dev);
+	domain = dca_find_domain(pci_rc);
+	if (list_empty(&domain->dca_providers))
+		dca_free_domain(domain);
+
 	spin_unlock_irqrestore(&dca_lock, flags);
  
 	dca_sysfs_remove_provider(dca);
@@ -175,7 +175,7 @@
  
 	dev_err(&pdev->dev, "Removing dma and dca services\n");
 	if (device->dca) {
-		unregister_dca_provider(device->dca);
+		unregister_dca_provider(device->dca, &pdev->dev);
 		free_dca_provider(device->dca);
 		device->dca = NULL;
 	}
@@ -20,6 +20,9 @@
  */
 #ifndef DCA_H
 #define DCA_H
+
+#include <linux/pci.h>
+
 /* DCA Provider API */
  
 /* DCA Notifier Interface */
@@ -36,6 +39,12 @@
 	int			 id;
 };
  
+struct dca_domain {
+	struct list_head	node;
+	struct list_head	dca_providers;
+	struct pci_bus		*pci_rc;
+};
+
 struct dca_ops {
 	int	(*add_requester)    (struct dca_provider *, struct device *);
 	int	(*remove_requester) (struct dca_provider *, struct device *);
@@ -47,7 +56,7 @@
 struct dca_provider *alloc_dca_provider(struct dca_ops *ops, int priv_size);
 void free_dca_provider(struct dca_provider *dca);
 int register_dca_provider(struct dca_provider *dca, struct device *dev);
-void unregister_dca_provider(struct dca_provider *dca);
+void unregister_dca_provider(struct dca_provider *dca, struct device *dev);
  
 static inline void *dca_priv(struct dca_provider *dca)
 {
...	...	@@ -28,7 +28,7 @@
28	28	#include <linux/device.h>
29	29	#include <linux/dca.h>
30	30
31		-#define DCA_VERSION "1.8"
	31	+#define DCA_VERSION "1.12.1"
32	32
33	33	MODULE_VERSION(DCA_VERSION);
34	34	MODULE_LICENSE("GPL");
35	35
36	36
37	37
38	38
...	...	@@ -36,20 +36,92 @@
36	36
37	37	static DEFINE_SPINLOCK(dca_lock);
38	38
39		-static LIST_HEAD(dca_providers);
	39	+static LIST_HEAD(dca_domains);
40	40
	41	+static struct pci_bus dca_pci_rc_from_dev(struct device dev)
	42	+{
	43	+ struct pci_dev *pdev = to_pci_dev(dev);
	44	+ struct pci_bus *bus = pdev->bus;
	45	+
	46	+ while (bus->parent)
	47	+ bus = bus->parent;
	48	+
	49	+ return bus;
	50	+}
	51	+
	52	+static struct dca_domain dca_allocate_domain(struct pci_bus rc)
	53	+{
	54	+ struct dca_domain *domain;
	55	+
	56	+ domain = kzalloc(sizeof(*domain), GFP_NOWAIT);
	57	+ if (!domain)
	58	+ return NULL;
	59	+
	60	+ INIT_LIST_HEAD(&domain->dca_providers);
	61	+ domain->pci_rc = rc;
	62	+
	63	+ return domain;
	64	+}
	65	+
	66	+static void dca_free_domain(struct dca_domain *domain)
	67	+{
	68	+ list_del(&domain->node);
	69	+ kfree(domain);
	70	+}
	71	+
	72	+static struct dca_domain dca_find_domain(struct pci_bus rc)
	73	+{
	74	+ struct dca_domain *domain;
	75	+
	76	+ list_for_each_entry(domain, &dca_domains, node)
	77	+ if (domain->pci_rc == rc)
	78	+ return domain;
	79	+
	80	+ return NULL;
	81	+}
	82	+
	83	+static struct dca_domain dca_get_domain(struct device dev)
	84	+{
	85	+ struct pci_bus *rc;
	86	+ struct dca_domain *domain;
	87	+
	88	+ rc = dca_pci_rc_from_dev(dev);
	89	+ domain = dca_find_domain(rc);
	90	+
	91	+ if (!domain) {
	92	+ domain = dca_allocate_domain(rc);
	93	+ if (domain)
	94	+ list_add(&domain->node, &dca_domains);
	95	+ }
	96	+
	97	+ return domain;
	98	+}
	99	+
41	100	static struct dca_provider dca_find_provider_by_dev(struct device dev)
42	101	{
43		- struct dca_provider dca, ret = NULL;
	102	+ struct dca_provider *dca;
	103	+ struct pci_bus *rc;
	104	+ struct dca_domain *domain;
44	105
45		- list_for_each_entry(dca, &dca_providers, node) {
46		- if ((!dev) \|\| (dca->ops->dev_managed(dca, dev))) {
47		- ret = dca;
48		- break;
49		- }
	106	+ if (dev) {
	107	+ rc = dca_pci_rc_from_dev(dev);
	108	+ domain = dca_find_domain(rc);
	109	+ if (!domain)
	110	+ return NULL;
	111	+ } else {
	112	+ if (!list_empty(&dca_domains))
	113	+ domain = list_first_entry(&dca_domains,
	114	+ struct dca_domain,
	115	+ node);
	116	+ else
	117	+ return NULL;
50	118	}
51	119
52		- return ret;
	120	+ list_for_each_entry(dca, &domain->dca_providers, node)
	121	+ if ((!dev) \|\| (dca->ops->dev_managed(dca, dev)))
	122	+ return dca;
	123	+
	124	+ return NULL;
53	125	}
54	126
55	127	/**
...	...	@@ -61,6 +133,8 @@
61	133	struct dca_provider *dca;
62	134	int err, slot = -ENODEV;
63	135	unsigned long flags;
	136	+ struct pci_bus *pci_rc;
	137	+ struct dca_domain *domain;
64	138
65	139	if (!dev)
66	140	return -EFAULT;
...	...	@@ -74,7 +148,14 @@
74	148	return -EEXIST;
75	149	}
76	150
77		- list_for_each_entry(dca, &dca_providers, node) {
	151	+ pci_rc = dca_pci_rc_from_dev(dev);
	152	+ domain = dca_find_domain(pci_rc);
	153	+ if (!domain) {
	154	+ spin_unlock_irqrestore(&dca_lock, flags);
	155	+ return -ENODEV;
	156	+ }
	157	+
	158	+ list_for_each_entry(dca, &domain->dca_providers, node) {
78	159	slot = dca->ops->add_requester(dca, dev);
79	160	if (slot >= 0)
80	161	break;
81	162
...	...	@@ -222,13 +303,19 @@
222	303	{
223	304	int err;
224	305	unsigned long flags;
	306	+ struct dca_domain *domain;
225	307
226	308	err = dca_sysfs_add_provider(dca, dev);
227	309	if (err)
228	310	return err;
229	311
230	312	spin_lock_irqsave(&dca_lock, flags);
231		- list_add(&dca->node, &dca_providers);
	313	+ domain = dca_get_domain(dev);
	314	+ if (!domain) {
	315	+ spin_unlock_irqrestore(&dca_lock, flags);
	316	+ return -ENODEV;
	317	+ }
	318	+ list_add(&dca->node, &domain->dca_providers);
232	319	spin_unlock_irqrestore(&dca_lock, flags);
233	320
234	321	blocking_notifier_call_chain(&dca_provider_chain,
235	322
236	323
237	324
...	...	@@ -241,15 +328,24 @@
241	328	* unregister_dca_provider - remove a dca provider
242	329	* @dca - struct created by alloc_dca_provider()
243	330	*/
244		-void unregister_dca_provider(struct dca_provider *dca)
	331	+void unregister_dca_provider(struct dca_provider dca, struct device dev)
245	332	{
246	333	unsigned long flags;
	334	+ struct pci_bus *pci_rc;
	335	+ struct dca_domain *domain;
247	336
248	337	blocking_notifier_call_chain(&dca_provider_chain,
249	338	DCA_PROVIDER_REMOVE, NULL);
250	339
251	340	spin_lock_irqsave(&dca_lock, flags);
	341	+
252	342	list_del(&dca->node);
	343	+
	344	+ pci_rc = dca_pci_rc_from_dev(dev);
	345	+ domain = dca_find_domain(pci_rc);
	346	+ if (list_empty(&domain->dca_providers))
	347	+ dca_free_domain(domain);
	348	+
253	349	spin_unlock_irqrestore(&dca_lock, flags);
254	350
255	351	dca_sysfs_remove_provider(dca);
...	...	@@ -175,7 +175,7 @@
175	175
176	176	dev_err(&pdev->dev, "Removing dma and dca services\n");
177	177	if (device->dca) {
178		- unregister_dca_provider(device->dca);
	178	+ unregister_dca_provider(device->dca, &pdev->dev);
179	179	free_dca_provider(device->dca);
180	180	device->dca = NULL;
181	181	}
...	...	@@ -20,6 +20,9 @@
20	20	*/
21	21	#ifndef DCA_H
22	22	#define DCA_H
	23	+
	24	+#include <linux/pci.h>
	25	+
23	26	/* DCA Provider API */
24	27
25	28	/* DCA Notifier Interface */
...	...	@@ -36,6 +39,12 @@
36	39	int id;
37	40	};
38	41
	42	+struct dca_domain {
	43	+ struct list_head node;
	44	+ struct list_head dca_providers;
	45	+ struct pci_bus *pci_rc;
	46	+};
	47	+
39	48	struct dca_ops {
40	49	int (add_requester) (struct dca_provider , struct device *);
41	50	int (remove_requester) (struct dca_provider , struct device *);
...	...	@@ -47,7 +56,7 @@
47	56	struct dca_provider alloc_dca_provider(struct dca_ops ops, int priv_size);
48	57	void free_dca_provider(struct dca_provider *dca);
49	58	int register_dca_provider(struct dca_provider dca, struct device dev);
50		-void unregister_dca_provider(struct dca_provider *dca);
	59	+void unregister_dca_provider(struct dca_provider dca, struct device dev);
51	60
52	61	static inline void dca_priv(struct dca_provider dca)
53	62	{