在 2022/2/3 下午3:27, Zhu Lingshan 写道:
This commit implements a MSIX vector allocation helper
for vqs and config interrupts.
Signed-off-by: Zhu Lingshan <lingshan.zhu@xxxxxxxxx>
---
drivers/vdpa/ifcvf/ifcvf_main.c | 35 +++++++++++++++++++++++++++++++--
1 file changed, 33 insertions(+), 2 deletions(-)
diff --git a/drivers/vdpa/ifcvf/ifcvf_main.c b/drivers/vdpa/ifcvf/ifcvf_main.c
index d1a6b5ab543c..44c89ab0b6da 100644
--- a/drivers/vdpa/ifcvf/ifcvf_main.c
+++ b/drivers/vdpa/ifcvf/ifcvf_main.c
@@ -58,14 +58,45 @@ static void ifcvf_free_irq(struct ifcvf_adapter *adapter, int queues)
ifcvf_free_irq_vectors(pdev);
}
+/* ifcvf MSIX vectors allocator, this helper tries to allocate
+ * vectors for all virtqueues and the config interrupt.
+ * It returns the number of allocated vectors, negative
+ * return value when fails.
+ */
+static int ifcvf_alloc_vectors(struct ifcvf_adapter *adapter)
+{
+ struct pci_dev *pdev = adapter->pdev;
+ struct ifcvf_hw *vf = &adapter->vf;
+ int max_intr, ret;
+
+ /* all queues and config interrupt */
+ max_intr = vf->nr_vring + 1;
+ ret = pci_alloc_irq_vectors(pdev, 1, max_intr, PCI_IRQ_MSIX | PCI_IRQ_AFFINITY);
+
+ if (ret < 0) {
+ IFCVF_ERR(pdev, "Failed to alloc IRQ vectors\n");
+ return ret;
+ }
+
+ if (ret < max_intr)
+ IFCVF_INFO(pdev,
+ "Requested %u vectors, however only %u allocated, lower performance\n",
+ max_intr, ret);
+
+ return ret;
+}
+
static int ifcvf_request_irq(struct ifcvf_adapter *adapter)
{
struct pci_dev *pdev = adapter->pdev;
struct ifcvf_hw *vf = &adapter->vf;
- int vector, i, ret, irq;
+ int vector, nvectors, i, ret, irq;
u16 max_intr;
- /* all queues and config interrupt */
+ nvectors = ifcvf_alloc_vectors(adapter);
+ if (!(nvectors > 0))
+ return nvectors;
Why not simply checking by using nvectors <= 0? If ifcvf_alloc_vectors
can return 0 this breaks the ifcvf_request_irq() caller's assumption.
+
max_intr = vf->nr_vring + 1;
ret = pci_alloc_irq_vectors(pdev, max_intr,
So irq is allocated twice here?
Thanks
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