PCI: endpoint: Add MSI-X interfaces

Add PCI_EPC_IRQ_MSIX type.

Add MSI-X callbacks signatures to the ops structure.

Add sysfs interface for set/get MSI-X capability maximum number.

Update documentation accordingly.

Signed-off-by: Gustavo Pimentel <gustavo.pimentel@synopsys.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Acked-by: Kishon Vijay Abraham I <kishon@ti.com>

2 files changed, 81 insertions, 0 deletions

diff --git a/drivers/pci/endpoint/pci-ep-cfs.c b/drivers/pci/endpoint/pci-ep-cfs.c
index 018ea3433cb5..d1288a0bd530 100644
--- a/drivers/pci/endpoint/pci-ep-cfs.c
+++ b/drivers/pci/endpoint/pci-ep-cfs.c
@@ -286,6 +286,28 @@ static ssize_t pci_epf_msi_interrupts_show(struct config_item *item,
 		       to_pci_epf_group(item)->epf->msi_interrupts);
 }
 
+static ssize_t pci_epf_msix_interrupts_store(struct config_item *item,
+					     const char *page, size_t len)
+{
+	u16 val;
+	int ret;
+
+	ret = kstrtou16(page, 0, &val);
+	if (ret)
+		return ret;
+
+	to_pci_epf_group(item)->epf->msix_interrupts = val;
+
+	return len;
+}
+
+static ssize_t pci_epf_msix_interrupts_show(struct config_item *item,
+					    char *page)
+{
+	return sprintf(page, "%d\n",
+		       to_pci_epf_group(item)->epf->msix_interrupts);
+}
+
 PCI_EPF_HEADER_R(vendorid)
 PCI_EPF_HEADER_W_u16(vendorid)
 
@@ -327,6 +349,7 @@ CONFIGFS_ATTR(pci_epf_, subsys_vendor_id);
 CONFIGFS_ATTR(pci_epf_, subsys_id);
 CONFIGFS_ATTR(pci_epf_, interrupt_pin);
 CONFIGFS_ATTR(pci_epf_, msi_interrupts);
+CONFIGFS_ATTR(pci_epf_, msix_interrupts);
 
 static struct configfs_attribute *pci_epf_attrs[] = {
 	&pci_epf_attr_vendorid,
@@ -340,6 +363,7 @@ static struct configfs_attribute *pci_epf_attrs[] = {
 	&pci_epf_attr_subsys_id,
 	&pci_epf_attr_interrupt_pin,
 	&pci_epf_attr_msi_interrupts,
+	&pci_epf_attr_msix_interrupts,
 	NULL,
 };
 
diff --git a/drivers/pci/endpoint/pci-epc-core.c b/drivers/pci/endpoint/pci-epc-core.c
index b0ee42739c3c..7d77bd0e5d4a 100644
--- a/drivers/pci/endpoint/pci-epc-core.c
+++ b/drivers/pci/endpoint/pci-epc-core.c
@@ -218,6 +218,63 @@ int pci_epc_set_msi(struct pci_epc *epc, u8 func_no, u8 interrupts)
 EXPORT_SYMBOL_GPL(pci_epc_set_msi);
 
 /**
+ * pci_epc_get_msix() - get the number of MSI-X interrupt numbers allocated
+ * @epc: the EPC device to which MSI-X interrupts was requested
+ * @func_no: the endpoint function number in the EPC device
+ *
+ * Invoke to get the number of MSI-X interrupts allocated by the RC
+ */
+int pci_epc_get_msix(struct pci_epc *epc, u8 func_no)
+{
+	int interrupt;
+	unsigned long flags;
+
+	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions)
+		return 0;
+
+	if (!epc->ops->get_msix)
+		return 0;
+
+	spin_lock_irqsave(&epc->lock, flags);
+	interrupt = epc->ops->get_msix(epc, func_no);
+	spin_unlock_irqrestore(&epc->lock, flags);
+
+	if (interrupt < 0)
+		return 0;
+
+	return interrupt + 1;
+}
+EXPORT_SYMBOL_GPL(pci_epc_get_msix);
+
+/**
+ * pci_epc_set_msix() - set the number of MSI-X interrupt numbers required
+ * @epc: the EPC device on which MSI-X has to be configured
+ * @func_no: the endpoint function number in the EPC device
+ * @interrupts: number of MSI-X interrupts required by the EPF
+ *
+ * Invoke to set the required number of MSI-X interrupts.
+ */
+int pci_epc_set_msix(struct pci_epc *epc, u8 func_no, u16 interrupts)
+{
+	int ret;
+	unsigned long flags;
+
+	if (IS_ERR_OR_NULL(epc) || func_no >= epc->max_functions ||
+	    interrupts < 1 || interrupts > 2048)
+		return -EINVAL;
+
+	if (!epc->ops->set_msix)
+		return 0;
+
+	spin_lock_irqsave(&epc->lock, flags);
+	ret = epc->ops->set_msix(epc, func_no, interrupts - 1);
+	spin_unlock_irqrestore(&epc->lock, flags);
+
+	return ret;
+}
+EXPORT_SYMBOL_GPL(pci_epc_set_msix);
+
+/**
  * pci_epc_unmap_addr() - unmap CPU address from PCI address
  * @epc: the EPC device on which address is allocated
  * @func_no: the endpoint function number in the EPC device