MIPS: Octeon: Move MSI code out of octeon-irq.c.

Put all the MSI code in one place (msi-octeon.c).  This simplifies
octeon-irq.c and gets rid of some ugly #ifdefs

Signed-off-by: David Daney <ddaney@caviumnetworks.com>
To: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/1484/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/pci/msi-octeon.c b/arch/mips/pci/msi-octeon.c
index 03742e6..1e31526 100644
--- a/arch/mips/pci/msi-octeon.c
+++ b/arch/mips/pci/msi-octeon.c
@@ -249,12 +249,99 @@
 	return IRQ_NONE;
 }
 
+static DEFINE_RAW_SPINLOCK(octeon_irq_msi_lock);
+
+static void octeon_irq_msi_ack(unsigned int irq)
+{
+	if (!octeon_has_feature(OCTEON_FEATURE_PCIE)) {
+		/* These chips have PCI */
+		cvmx_write_csr(CVMX_NPI_NPI_MSI_RCV,
+			       1ull << (irq - OCTEON_IRQ_MSI_BIT0));
+	} else {
+		/*
+		 * These chips have PCIe. Thankfully the ACK doesn't
+		 * need any locking.
+		 */
+		cvmx_write_csr(CVMX_PEXP_NPEI_MSI_RCV0,
+			       1ull << (irq - OCTEON_IRQ_MSI_BIT0));
+	}
+}
+
+static void octeon_irq_msi_eoi(unsigned int irq)
+{
+	/* Nothing needed */
+}
+
+static void octeon_irq_msi_enable(unsigned int irq)
+{
+	if (!octeon_has_feature(OCTEON_FEATURE_PCIE)) {
+		/*
+		 * Octeon PCI doesn't have the ability to mask/unmask
+		 * MSI interrupts individually.  Instead of
+		 * masking/unmasking them in groups of 16, we simple
+		 * assume MSI devices are well behaved.  MSI
+		 * interrupts are always enable and the ACK is assumed
+		 * to be enough.
+		 */
+	} else {
+		/* These chips have PCIe.  Note that we only support
+		 * the first 64 MSI interrupts.  Unfortunately all the
+		 * MSI enables are in the same register.  We use
+		 * MSI0's lock to control access to them all.
+		 */
+		uint64_t en;
+		unsigned long flags;
+		raw_spin_lock_irqsave(&octeon_irq_msi_lock, flags);
+		en = cvmx_read_csr(CVMX_PEXP_NPEI_MSI_ENB0);
+		en |= 1ull << (irq - OCTEON_IRQ_MSI_BIT0);
+		cvmx_write_csr(CVMX_PEXP_NPEI_MSI_ENB0, en);
+		cvmx_read_csr(CVMX_PEXP_NPEI_MSI_ENB0);
+		raw_spin_unlock_irqrestore(&octeon_irq_msi_lock, flags);
+	}
+}
+
+static void octeon_irq_msi_disable(unsigned int irq)
+{
+	if (!octeon_has_feature(OCTEON_FEATURE_PCIE)) {
+		/* See comment in enable */
+	} else {
+		/*
+		 * These chips have PCIe.  Note that we only support
+		 * the first 64 MSI interrupts.  Unfortunately all the
+		 * MSI enables are in the same register.  We use
+		 * MSI0's lock to control access to them all.
+		 */
+		uint64_t en;
+		unsigned long flags;
+		raw_spin_lock_irqsave(&octeon_irq_msi_lock, flags);
+		en = cvmx_read_csr(CVMX_PEXP_NPEI_MSI_ENB0);
+		en &= ~(1ull << (irq - OCTEON_IRQ_MSI_BIT0));
+		cvmx_write_csr(CVMX_PEXP_NPEI_MSI_ENB0, en);
+		cvmx_read_csr(CVMX_PEXP_NPEI_MSI_ENB0);
+		raw_spin_unlock_irqrestore(&octeon_irq_msi_lock, flags);
+	}
+}
+
+static struct irq_chip octeon_irq_chip_msi = {
+	.name = "MSI",
+	.enable = octeon_irq_msi_enable,
+	.disable = octeon_irq_msi_disable,
+	.ack = octeon_irq_msi_ack,
+	.eoi = octeon_irq_msi_eoi,
+};
 
 /*
  * Initializes the MSI interrupt handling code
  */
-int octeon_msi_initialize(void)
+static int __init octeon_msi_initialize(void)
 {
+	int irq;
+
+	for (irq = OCTEON_IRQ_MSI_BIT0; irq <= OCTEON_IRQ_MSI_BIT63; irq++) {
+		set_irq_chip_and_handler(irq, &octeon_irq_chip_msi,
+					 handle_percpu_irq);
+	}
+
 	if (octeon_has_feature(OCTEON_FEATURE_PCIE)) {
 		if (request_irq(OCTEON_IRQ_PCI_MSI0, octeon_msi_interrupt,
 				IRQF_SHARED,
@@ -284,5 +371,4 @@
 	}
 	return 0;
 }
-
 subsys_initcall(octeon_msi_initialize);