diff options
Diffstat (limited to 'arch/powerpc/platforms/pasemi/msi.c')
| -rw-r--r-- | arch/powerpc/platforms/pasemi/msi.c | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/arch/powerpc/platforms/pasemi/msi.c b/arch/powerpc/platforms/pasemi/msi.c new file mode 100644 index 000000000..dc1846660 --- /dev/null +++ b/arch/powerpc/platforms/pasemi/msi.c @@ -0,0 +1,161 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright 2007, Olof Johansson, PA Semi + * + * Based on arch/powerpc/sysdev/mpic_u3msi.c: + * + * Copyright 2006, Segher Boessenkool, IBM Corporation. + * Copyright 2006-2007, Michael Ellerman, IBM Corporation. + */ + +#include <linux/irq.h> +#include <linux/irqdomain.h> +#include <linux/msi.h> +#include <asm/mpic.h> +#include <asm/hw_irq.h> +#include <asm/ppc-pci.h> +#include <asm/msi_bitmap.h> + +#include <sysdev/mpic.h> + +/* Allocate 16 interrupts per device, to give an alignment of 16, + * since that's the size of the grouping w.r.t. affinity. If someone + * needs more than 32 MSI's down the road we'll have to rethink this, + * but it should be OK for now. + */ +#define ALLOC_CHUNK 16 + +#define PASEMI_MSI_ADDR 0xfc080000 + +/* A bit ugly, can we get this from the pci_dev somehow? */ +static struct mpic *msi_mpic; + + +static void mpic_pasemi_msi_mask_irq(struct irq_data *data) +{ + pr_debug("mpic_pasemi_msi_mask_irq %d\n", data->irq); + pci_msi_mask_irq(data); + mpic_mask_irq(data); +} + +static void mpic_pasemi_msi_unmask_irq(struct irq_data *data) +{ + pr_debug("mpic_pasemi_msi_unmask_irq %d\n", data->irq); + mpic_unmask_irq(data); + pci_msi_unmask_irq(data); +} + +static struct irq_chip mpic_pasemi_msi_chip = { + .irq_shutdown = mpic_pasemi_msi_mask_irq, + .irq_mask = mpic_pasemi_msi_mask_irq, + .irq_unmask = mpic_pasemi_msi_unmask_irq, + .irq_eoi = mpic_end_irq, + .irq_set_type = mpic_set_irq_type, + .irq_set_affinity = mpic_set_affinity, + .name = "PASEMI-MSI", +}; + +static void pasemi_msi_teardown_msi_irqs(struct pci_dev *pdev) +{ + struct msi_desc *entry; + irq_hw_number_t hwirq; + + pr_debug("pasemi_msi_teardown_msi_irqs, pdev %p\n", pdev); + + msi_for_each_desc(entry, &pdev->dev, MSI_DESC_ASSOCIATED) { + hwirq = virq_to_hw(entry->irq); + irq_set_msi_desc(entry->irq, NULL); + irq_dispose_mapping(entry->irq); + msi_bitmap_free_hwirqs(&msi_mpic->msi_bitmap, hwirq, ALLOC_CHUNK); + } +} + +static int pasemi_msi_setup_msi_irqs(struct pci_dev *pdev, int nvec, int type) +{ + unsigned int virq; + struct msi_desc *entry; + struct msi_msg msg; + int hwirq; + + if (type == PCI_CAP_ID_MSIX) + pr_debug("pasemi_msi: MSI-X untested, trying anyway\n"); + pr_debug("pasemi_msi_setup_msi_irqs, pdev %p nvec %d type %d\n", + pdev, nvec, type); + + msg.address_hi = 0; + msg.address_lo = PASEMI_MSI_ADDR; + + msi_for_each_desc(entry, &pdev->dev, MSI_DESC_NOTASSOCIATED) { + /* Allocate 16 interrupts for now, since that's the grouping for + * affinity. This can be changed later if it turns out 32 is too + * few MSIs for someone, but restrictions will apply to how the + * sources can be changed independently. + */ + hwirq = msi_bitmap_alloc_hwirqs(&msi_mpic->msi_bitmap, + ALLOC_CHUNK); + if (hwirq < 0) { + pr_debug("pasemi_msi: failed allocating hwirq\n"); + return hwirq; + } + + virq = irq_create_mapping(msi_mpic->irqhost, hwirq); + if (!virq) { + pr_debug("pasemi_msi: failed mapping hwirq 0x%x\n", + hwirq); + msi_bitmap_free_hwirqs(&msi_mpic->msi_bitmap, hwirq, + ALLOC_CHUNK); + return -ENOSPC; + } + + /* Vector on MSI is really an offset, the hardware adds + * it to the value written at the magic address. So set + * it to 0 to remain sane. + */ + mpic_set_vector(virq, 0); + + irq_set_msi_desc(virq, entry); + irq_set_chip(virq, &mpic_pasemi_msi_chip); + irq_set_irq_type(virq, IRQ_TYPE_EDGE_RISING); + + pr_debug("pasemi_msi: allocated virq 0x%x (hw 0x%x) " \ + "addr 0x%x\n", virq, hwirq, msg.address_lo); + + /* Likewise, the device writes [0...511] into the target + * register to generate MSI [512...1023] + */ + msg.data = hwirq-0x200; + pci_write_msi_msg(virq, &msg); + } + + return 0; +} + +int __init mpic_pasemi_msi_init(struct mpic *mpic) +{ + int rc; + struct pci_controller *phb; + struct device_node *of_node; + + of_node = irq_domain_get_of_node(mpic->irqhost); + if (!of_node || + !of_device_is_compatible(of_node, + "pasemi,pwrficient-openpic")) + return -ENODEV; + + rc = mpic_msi_init_allocator(mpic); + if (rc) { + pr_debug("pasemi_msi: Error allocating bitmap!\n"); + return rc; + } + + pr_debug("pasemi_msi: Registering PA Semi MPIC MSI callbacks\n"); + + msi_mpic = mpic; + list_for_each_entry(phb, &hose_list, list_node) { + WARN_ON(phb->controller_ops.setup_msi_irqs); + phb->controller_ops.setup_msi_irqs = pasemi_msi_setup_msi_irqs; + phb->controller_ops.teardown_msi_irqs = pasemi_msi_teardown_msi_irqs; + } + + return 0; +} |