[PATCH 3/4] PCI: Allow registering reset method

[Gavin Shan]

The patch exposes function pci_dev_add_specific_reset() to allow
registering PCI device specific reset methods.

Signed-off-by: Gavin Shan <gwshan at linux.vnet.ibm.com>
---
 drivers/pci/quirks.c | 64 ++++++++++++++++++++++++++++++++++++++++++++++++++++
 include/linux/pci.h  |  9 ++++++++
 2 files changed, 73 insertions(+)

diff --git a/drivers/pci/quirks.c b/drivers/pci/quirks.c
index 37f4c5d..ef811ec 100644
--- a/drivers/pci/quirks.c
+++ b/drivers/pci/quirks.c
@@ -3534,6 +3534,70 @@ static struct pci_dev_reset_method pci_dev_reset_methods[] = {
 	}
 };
 
+static bool pci_dev_reset_match(struct pci_dev_reset_method *m,
+				u16 vendor, u16 device,
+				int (*reset)(struct pci_dev *, int))
+{
+	if (m->vendor != (u16)PCI_ANY_ID &&
+	    vendor != (u16)PCI_ANY_ID &&
+	    m->vendor != vendor)
+		return false;
+
+	if (m->device != (u16)PCI_ANY_ID &&
+	    device != (u16)PCI_ANY_ID &&
+	    m->device != device)
+		return false;
+
+	if (m->reset != reset)
+		return false;
+
+	return true;
+}
+
+int pci_dev_add_specific_reset(u16 vendor, u16 device,
+			       int (*reset)(struct pci_dev *, int))
+{
+	struct pci_dev_reset_method *m, *method;
+	int i;
+
+	/* Always expect valid handler */
+	if (!reset)
+		return -EINVAL;
+
+	method = kzalloc(sizeof(*method), GFP_KERNEL);
+	if (!method)
+		return -ENOMEM;
+
+	/* Check if we have conflicting method */
+	mutex_lock(&pci_dev_reset_mutex);
+	if (!pci_dev_reset_populated) {
+		for (i = 0; i < ARRAY_SIZE(pci_dev_reset_methods); i++) {
+			m = &pci_dev_reset_methods[i];
+			if (pci_dev_reset_match(m, vendor, device, reset))
+				goto found;
+		}
+	} else {
+		list_for_each_entry(m, &pci_dev_reset_list, node) {
+			if (pci_dev_reset_match(m, vendor, device, reset))
+				goto found;
+		}
+	}
+
+	/* Populate it */
+	method->vendor = vendor;
+	method->device = device;
+	method->reset  = reset;
+	INIT_LIST_HEAD(&method->node);
+	list_add_tail(&method->node, &pci_dev_reset_list);
+	mutex_unlock(&pci_dev_reset_mutex);
+	return 0;
+found:
+	mutex_unlock(&pci_dev_reset_mutex);
+	kfree(method);
+	return -EEXIST;
+}
+EXPORT_SYMBOL(pci_dev_add_specific_reset);
+
 static void pci_dev_populate_reset(void)
 {
 	struct pci_dev_reset_method *m;
diff --git a/include/linux/pci.h b/include/linux/pci.h
index 211e9da..b98be1a 100644
--- a/include/linux/pci.h
+++ b/include/linux/pci.h
@@ -1605,6 +1605,8 @@ enum pci_fixup_pass {
 
 #ifdef CONFIG_PCI_QUIRKS
 void pci_fixup_device(enum pci_fixup_pass pass, struct pci_dev *dev);
+int pci_dev_add_specific_reset(u16 vendor, u16 device,
+			       int (*reset)(struct pci_dev *, int));
 int pci_dev_specific_acs_enabled(struct pci_dev *dev, u16 acs_flags);
 void pci_dev_specific_enable_acs(struct pci_dev *dev);
 #else
@@ -1615,6 +1617,13 @@ static inline int pci_dev_specific_acs_enabled(struct pci_dev *dev,
 {
 	return -ENOTTY;
 }
+
+int pci_dev_add_specific_reset(u16 vendor, u16 device,
+			       int (*reset)(struct pci_dev *, int))
+{
+	return -ENOTTY;
+}
+
 static inline void pci_dev_specific_enable_acs(struct pci_dev *dev) { }
 #endif
 
-- 
1.8.3.2