Re: [PATCH v3 08/10] PCI: apple: Implement MSI support
From: Alyssa Rosenzweig <hidden>
Date: 2021-09-13 20:44:47
Also in:
linux-pci, lkml
+static void apple_msi_compose_msg(struct irq_data *data, struct msi_msg *msg)
+{
+ BUILD_BUG_ON(upper_32_bits(DOORBELL_ADDR));
+
+ msg->address_hi = upper_32_bits(DOORBELL_ADDR);
+ msg->address_lo = lower_32_bits(DOORBELL_ADDR);
+ msg->data = data->hwirq;
+}...
quoted hunk ↗ jump to hunk
@@ -269,6 +378,14 @@ static int apple_pcie_port_setup_irq(struct apple_pcie_port *port) irq_set_chained_handler_and_data(irq, apple_port_irq_handler, port); + /* Configure MSI base address */ + writel_relaxed(lower_32_bits(DOORBELL_ADDR), port->base + PORT_MSIADDR); + + /* Enable MSIs, shared between all ports */ + writel_relaxed(0, port->base + PORT_MSIBASE); + writel_relaxed((ilog2(port->pcie->nvecs) << PORT_MSICFG_L2MSINUM_SHIFT) | + PORT_MSICFG_EN, port->base + PORT_MSICFG); + return 0; }
I think the BUILD_BUG_ON makes more sense next to configuring the base address (which only has a 32-bit register, the BUILD_BUG_ON justifies using writel and not writeq), rather than configuring the message (which specifies the full 64-bits).