PCI: rcar: Add multi-MSI support

Implement the MSI .setup_irqs() method which enables allocation of several
MSIs at once.

[Sergei Shtylyov: removed unrelated/unneeded changes, fixed too long lines,
reordered the variable declarations, reworded the summary/description.]
Signed-off-by: Grigory Kletsko <grigory.kletsko@cogentembedded.com>
Signed-off-by: Sergei Shtylyov <sergei.shtylyov@cogentembedded.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Acked-by: Simon Horman <horms+renesas@verge.net.au>

diff --git a/drivers/pci/host/pcie-rcar.c b/drivers/pci/host/pcie-rcar.c
index 45dc3cd..d6e72db 100644 (file)
--- a/drivers/pci/host/pcie-rcar.c
+++ b/drivers/pci/host/pcie-rcar.c
@@ -608,6 +608,18 @@ static int rcar_msi_alloc(struct rcar_msi *chip)
        return msi;
 }
 
+static int rcar_msi_alloc_region(struct rcar_msi *chip, int no_irqs)
+{
+       int msi;
+
+       mutex_lock(&chip->lock);
+       msi = bitmap_find_free_region(chip->used, INT_PCI_MSI_NR,
+                                     order_base_2(no_irqs));
+       mutex_unlock(&chip->lock);
+
+       return msi;
+}
+
 static void rcar_msi_free(struct rcar_msi *chip, unsigned long irq)
 {
        mutex_lock(&chip->lock);
@@ -665,7 +677,7 @@ static int rcar_msi_setup_irq(struct msi_controller *chip, struct pci_dev *pdev,
        if (hwirq < 0)
                return hwirq;
 
-       irq = irq_create_mapping(msi->domain, hwirq);
+       irq = irq_find_mapping(msi->domain, hwirq);
        if (!irq) {
                rcar_msi_free(msi, hwirq);
                return -EINVAL;
@@ -682,6 +694,58 @@ static int rcar_msi_setup_irq(struct msi_controller *chip, struct pci_dev *pdev,
        return 0;
 }
 
+static int rcar_msi_setup_irqs(struct msi_controller *chip,
+                              struct pci_dev *pdev, int nvec, int type)
+{
+       struct rcar_pcie *pcie = container_of(chip, struct rcar_pcie, msi.chip);
+       struct rcar_msi *msi = to_rcar_msi(chip);
+       struct msi_desc *desc;
+       struct msi_msg msg;
+       unsigned int irq;
+       int hwirq;
+       int i;
+
+       /* MSI-X interrupts are not supported */
+       if (type == PCI_CAP_ID_MSIX)
+               return -EINVAL;
+
+       WARN_ON(!list_is_singular(&pdev->dev.msi_list));
+       desc = list_entry(pdev->dev.msi_list.next, struct msi_desc, list);
+
+       hwirq = rcar_msi_alloc_region(msi, nvec);
+       if (hwirq < 0)
+               return -ENOSPC;
+
+       irq = irq_find_mapping(msi->domain, hwirq);
+       if (!irq)
+               return -ENOSPC;
+
+       for (i = 0; i < nvec; i++) {
+               /*
+                * irq_create_mapping() called from rcar_pcie_probe() pre-
+                * allocates descs,  so there is no need to allocate descs here.
+                * We can therefore assume that if irq_find_mapping() above
+                * returns non-zero, then the descs are also successfully
+                * allocated.
+                */
+               if (irq_set_msi_desc_off(irq, i, desc)) {
+                       /* TODO: clear */
+                       return -EINVAL;
+               }
+       }
+
+       desc->nvec_used = nvec;
+       desc->msi_attrib.multiple = order_base_2(nvec);
+
+       msg.address_lo = rcar_pci_read_reg(pcie, PCIEMSIALR) & ~MSIFE;
+       msg.address_hi = rcar_pci_read_reg(pcie, PCIEMSIAUR);
+       msg.data = hwirq;
+
+       pci_write_msi_msg(irq, &msg);
+
+       return 0;
+}
+
 static void rcar_msi_teardown_irq(struct msi_controller *chip, unsigned int irq)
 {
        struct rcar_msi *msi = to_rcar_msi(chip);
@@ -716,12 +780,13 @@ static int rcar_pcie_enable_msi(struct rcar_pcie *pcie)
        struct platform_device *pdev = to_platform_device(pcie->dev);
        struct rcar_msi *msi = &pcie->msi;
        unsigned long base;
-       int err;
+       int err, i;
 
        mutex_init(&msi->lock);
 
        msi->chip.dev = pcie->dev;
        msi->chip.setup_irq = rcar_msi_setup_irq;
+       msi->chip.setup_irqs = rcar_msi_setup_irqs;
        msi->chip.teardown_irq = rcar_msi_teardown_irq;
 
        msi->domain = irq_domain_add_linear(pcie->dev->of_node, INT_PCI_MSI_NR,
@@ -731,6 +796,9 @@ static int rcar_pcie_enable_msi(struct rcar_pcie *pcie)
                return -ENOMEM;
        }
 
+       for (i = 0; i < INT_PCI_MSI_NR; i++)
+               irq_create_mapping(msi->domain, i);
+
        /* Two irqs are for MSI, but they are also used for non-MSI irqs */
        err = devm_request_irq(&pdev->dev, msi->irq1, rcar_pcie_msi_irq,
                               IRQF_SHARED | IRQF_NO_THREAD,