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>

5 files changed, 93 insertions, 0 deletions

diff --git a/Documentation/PCI/endpoint/function/binding/pci-test.txt b/Documentation/PCI/endpoint/function/binding/pci-test.txt
index 3b68b955fb50..cd76ba47394b 100644
--- a/Documentation/PCI/endpoint/function/binding/pci-test.txt
+++ b/Documentation/PCI/endpoint/function/binding/pci-test.txt
@@ -15,3 +15,5 @@ subsys_id	 : don't care
 interrupt_pin    : Should be 1 - INTA, 2 - INTB, 3 - INTC, 4 -INTD
 msi_interrupts   : Should be 1 to 32 depending on the number of MSI interrupts
                    to test
+msix_interrupts  : Should be 1 to 2048 depending on the number of MSI-X
+                   interrupts to test
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
diff --git a/include/linux/pci-epc.h b/include/linux/pci-epc.h
index 243eaa5a66ff..89f079f582df 100644
--- a/include/linux/pci-epc.h
+++ b/include/linux/pci-epc.h
@@ -17,6 +17,7 @@ enum pci_epc_irq_type {
         PCI_EPC_IRQ_UNKNOWN,
         PCI_EPC_IRQ_LEGACY,
         PCI_EPC_IRQ_MSI,
+        PCI_EPC_IRQ_MSIX,
 };
 
 /**
@@ -30,6 +31,10 @@ enum pci_epc_irq_type {
  *           capability register
  * @get_msi: ops to get the number of MSI interrupts allocated by the RC from
  *           the MSI capability register
+ * @set_msix: ops to set the requested number of MSI-X interrupts in the
+ *           MSI-X capability register
+ * @get_msix: ops to get the number of MSI-X interrupts allocated by the RC
+ *           from the MSI-X capability register
  * @raise_irq: ops to raise a legacy or MSI interrupt
  * @start: ops to start the PCI link
  * @stop: ops to stop the PCI link
@@ -48,6 +53,8 @@ struct pci_epc_ops {
                               phys_addr_t addr);
         int     (*set_msi)(struct pci_epc *epc, u8 func_no, u8 interrupts);
         int     (*get_msi)(struct pci_epc *epc, u8 func_no);
+        int     (*set_msix)(struct pci_epc *epc, u8 func_no, u16 interrupts);
+        int     (*get_msix)(struct pci_epc *epc, u8 func_no);
         int     (*raise_irq)(struct pci_epc *epc, u8 func_no,
                              enum pci_epc_irq_type type, u8 interrupt_num);
         int     (*start)(struct pci_epc *epc);
@@ -144,6 +151,8 @@ void pci_epc_unmap_addr(struct pci_epc *epc, u8 func_no,
                         phys_addr_t phys_addr);
 int pci_epc_set_msi(struct pci_epc *epc, u8 func_no, u8 interrupts);
 int pci_epc_get_msi(struct pci_epc *epc, u8 func_no);
+int pci_epc_set_msix(struct pci_epc *epc, u8 func_no, u16 interrupts);
+int pci_epc_get_msix(struct pci_epc *epc, u8 func_no);
 int pci_epc_raise_irq(struct pci_epc *epc, u8 func_no,
                       enum pci_epc_irq_type type, u8 interrupt_num);
 int pci_epc_start(struct pci_epc *epc);
diff --git a/include/linux/pci-epf.h b/include/linux/pci-epf.h
index 4e7764935fa8..ec02f58758c8 100644
--- a/include/linux/pci-epf.h
+++ b/include/linux/pci-epf.h
@@ -119,6 +119,7 @@ struct pci_epf {
         struct pci_epf_header   *header;
         struct pci_epf_bar      bar[6];
         u8                      msi_interrupts;
+        u16                     msix_interrupts;
         u8                      func_no;
 
         struct pci_epc          *epc;