[PATCH] irqchip: irq-mvebu-odmi: new driver
Marc Zyngier
marc.zyngier at arm.com
Mon Feb 15 01:14:15 PST 2016
Hi Thomas,
On 15/02/16 07:42, Thomas Petazzoni wrote:
> This commits adds a new irqchip driver that handles the ODMI
> controller found on Marvell 7K/8K processors. The ODMI controller
> provide MSI interrupt functionality to on-board peripherals, much like
> the GIC-v2m.
May I suggest a title that says a bit more than just "new driver"?
Something a bit more descriptive like "Platform MSI support"?
>
> Signed-off-by: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
> ---
> .../marvell,odmi-controller.txt | 36 +++
> drivers/irqchip/Kconfig | 4 +
> drivers/irqchip/Makefile | 1 +
> drivers/irqchip/irq-mvebu-odmi.c | 270 +++++++++++++++++++++
> 4 files changed, 311 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/interrupt-controller/marvell,odmi-controller.txt
> create mode 100644 drivers/irqchip/irq-mvebu-odmi.c
>
> diff --git a/Documentation/devicetree/bindings/interrupt-controller/marvell,odmi-controller.txt b/Documentation/devicetree/bindings/interrupt-controller/marvell,odmi-controller.txt
> new file mode 100644
> index 0000000..a2470af
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/interrupt-controller/marvell,odmi-controller.txt
> @@ -0,0 +1,36 @@
> +
> +* Marvell ODMI for MSI support
> +
> +Some Marvell SoCs have an On-Die Message Interrupt (ODMI) controller
> +which can be used by on-board peripheral for MSI interrupts.
> +
> +Required properties:
> +
> +- compatible : The value here should contain "marvell,odmi-controller".
> +
> +- interrupt,controller : Identifies the node as an interrupt controller.
> +
> +- msi-controller : Identifies the node as an MSI controller.
> +
> +- marvell,odmi-frames : Number of ODMI frames available. Each frame
> + provides a number of events.
> +
> +- reg : List of register definitions, one for each
> + ODMI frame.
> +
> +- marvell,spi-base : List of GIC base SPI interrupts, one for each
> + ODMI frame.
Please add a pointer to the GIC documentation, so that it is explicit
what SPIs are. Also, is the SPI number 0 based? or 32 based? Looking at
the code, it looks to be 32-based.
Please document the need for an "interrupt-parent" property, which may
be implicit in a DT, but fundamental to the understanding of the system.
> +
> +Example:
> +
> + odmi: odmi at 300000 {
> + compatible = "marvell,odmi-controller";
> + interrupt-controller;
> + msi-controller;
> + marvell,odmi-frames = <4>;
> + reg = <0x300000 0x4000>,
> + <0x304000 0x4000>,
> + <0x308000 0x4000>,
> + <0x30C000 0x4000>;
> + marvell,spi-base = <128>, <136>, <144>, <152>;
> + };
> diff --git a/drivers/irqchip/Kconfig b/drivers/irqchip/Kconfig
> index 715923d..18bed3c 100644
> --- a/drivers/irqchip/Kconfig
> +++ b/drivers/irqchip/Kconfig
> @@ -217,3 +217,7 @@ config IRQ_MXS
> def_bool y if MACH_ASM9260 || ARCH_MXS
> select IRQ_DOMAIN
> select STMP_DEVICE
> +
> +config MVEBU_ODMI
> + bool
> + select GENERIC_MSI_IRQ_DOMAIN
> diff --git a/drivers/irqchip/Makefile b/drivers/irqchip/Makefile
> index 18caacb..29c388f 100644
> --- a/drivers/irqchip/Makefile
> +++ b/drivers/irqchip/Makefile
> @@ -59,3 +59,4 @@ obj-$(CONFIG_ARCH_SA1100) += irq-sa11x0.o
> obj-$(CONFIG_INGENIC_IRQ) += irq-ingenic.o
> obj-$(CONFIG_IMX_GPCV2) += irq-imx-gpcv2.o
> obj-$(CONFIG_PIC32_EVIC) += irq-pic32-evic.o
> +obj-$(CONFIG_MVEBU_ODMI) += irq-mvebu-odmi.o
> diff --git a/drivers/irqchip/irq-mvebu-odmi.c b/drivers/irqchip/irq-mvebu-odmi.c
> new file mode 100644
> index 0000000..c3e00b9
> --- /dev/null
> +++ b/drivers/irqchip/irq-mvebu-odmi.c
> @@ -0,0 +1,270 @@
> +/*
> + * Copyright (C) 2016 Marvell
> + *
> + * Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
> + *
> + * This file is licensed under the terms of the GNU General Public
> + * License version 2. This program is licensed "as is" without any
> + * warranty of any kind, whether express or implied.
> + */
> +
> +#define pr_fmt(fmt) "GIC-ODMI: " fmt
> +
> +#include <linux/irq.h>
> +#include <linux/irqchip.h>
> +#include <linux/irqdomain.h>
> +#include <linux/kernel.h>
> +#include <linux/msi.h>
> +#include <linux/of_address.h>
> +#include <linux/slab.h>
> +#include <dt-bindings/interrupt-controller/arm-gic.h>
> +
> +#define GICP_ODMIN_SET 0x40
> +#define GICP_ODMI_INT_NUM_SHIFT 12
> +#define GICP_ODMIN_GM_EP_R0 0x110
> +#define GICP_ODMIN_GM_EP_R1 0x114
> +#define GICP_ODMIN_GM_EA_R0 0x108
> +#define GICP_ODMIN_GM_EA_R1 0x118
> +
> +/*
> + * We don't support the group events, so we simply have 8 interrupts
> + * per frame.
> + */
> +#define NODMIS_PER_FRAME 8
> +
> +struct odmi_data {
> + struct resource res;
> + void __iomem *base;
> + unsigned int spi_base;
> + unsigned long bm;
So you keep a bitmap per frame? That seems a bit odd - see below.
> +};
> +
> +static struct odmi_data *odmis;
> +static unsigned int odmis_count;
> +
> +/*
> + * Lock protecting the allocation bitmap embedded in the odmi_data
> + * structure. Only one spinlock is used, since allocation/freeing of
> + * MSI interrupts is infrequent.
> + */
> +static DEFINE_SPINLOCK(odmis_lock);
> +
> +static int odmi_set_affinity(struct irq_data *irq_data,
> + const struct cpumask *mask, bool force)
> +{
> + int ret;
> +
> + ret = irq_chip_set_affinity_parent(irq_data, mask, force);
> + if (ret == IRQ_SET_MASK_OK)
> + ret = IRQ_SET_MASK_OK_DONE;
I'm planning to fix GICv2 so that we don't need that anymore (much like
Antoine did got GICv3 in his Alpine series).
> +
> + return ret;
> +}
> +
> +static void odmi_compose_msi_msg(struct irq_data *data, struct msi_msg *msg)
> +{
> + struct odmi_data *odmi = NULL;
> + phys_addr_t addr;
> + unsigned int odmi_offset, i;
> +
> + /* Search the ODMI frame handling this interrupt */
> + for (i = 0; i < odmis_count; i++) {
> + if (data->hwirq >= odmis[i].spi_base &&
> + data->hwirq < (odmis[i].spi_base + NODMIS_PER_FRAME)) {
> + odmi = &odmis[i];
> + break;
> + }
> + }
So assume that instead of a bitmap per frame, you have a global one, and
hwirq is just the bit number in the bitmap. You have 8 interrupts per
frame, so you can compute things like this:
odmi = &odmi[data->hwirq >> 3];
odmi_offset = odmi->spi_base + (data->hwirq & 3);
Job done.
> +
> + if (WARN_ON(!odmi))
> + return;
> +
> + odmi_offset = (data->hwirq - odmi->spi_base);
> +
> + addr = odmi->res.start + GICP_ODMIN_SET;
> +
> + msg->address_hi = upper_32_bits(addr);
> + msg->address_lo = lower_32_bits(addr);
> + msg->data = odmi_offset << GICP_ODMI_INT_NUM_SHIFT;
> +}
> +
> +static struct irq_chip odmi_irq_chip = {
> + .name = "ODMI",
> + .irq_mask = irq_chip_mask_parent,
> + .irq_unmask = irq_chip_unmask_parent,
> + .irq_eoi = irq_chip_eoi_parent,
> + .irq_set_affinity = odmi_set_affinity,
> + .irq_compose_msi_msg = odmi_compose_msi_msg,
> +};
> +
> +static int odmi_irq_domain_alloc(struct irq_domain *domain, unsigned int virq,
> + unsigned int nr_irqs, void *args)
> +{
> + struct odmi_data *odmi = NULL;
> + struct irq_fwspec fwspec;
> + struct irq_data *d;
> + unsigned int offset, hwirq;
> + int i, ret;
> +
> + spin_lock(&odmis_lock);
> + for (i = 0; i < odmis_count; i++) {
> + offset = find_first_zero_bit(&odmis[i].bm, NODMIS_PER_FRAME);
> + if (offset < NODMIS_PER_FRAME) {
> + __set_bit(offset, &odmis[i].bm);
> + odmi = &odmis[i];
> + break;
> + }
> + }
> + spin_unlock(&odmis_lock);
And this becomes much simpler.
> +
> + if (!odmi)
> + return -ENOSPC;
> +
> + hwirq = odmi->spi_base + offset;
> +
> + fwspec.fwnode = domain->parent->fwnode;
> + fwspec.param_count = 3;
> + fwspec.param[0] = GIC_SPI;
> + fwspec.param[1] = hwirq - 32;
> + fwspec.param[2] = IRQ_TYPE_EDGE_RISING;
> +
> + ret = irq_domain_alloc_irqs_parent(domain, virq, 1, &fwspec);
> + if (ret) {
> + pr_err("Cannot allocate parent IRQ\n");
> + spin_lock(&odmis_lock);
> + __clear_bit(offset, &odmi->bm);
> + spin_unlock(&odmis_lock);
> + return ret;
> + }
> +
> + /* Configure the interrupt line to be edge */
> + d = irq_domain_get_irq_data(domain->parent, virq);
> + d->chip->irq_set_type(d, IRQ_TYPE_EDGE_RISING);
> +
> + irq_domain_set_hwirq_and_chip(domain, virq, hwirq,
> + &odmi_irq_chip, NULL);
> +
> + return 0;
> +}
> +
> +static void odmi_irq_domain_free(struct irq_domain *domain,
> + unsigned int virq, unsigned int nr_irqs)
> +{
> + struct irq_data *d = irq_domain_get_irq_data(domain, virq);
> + struct odmi_data *odmi = NULL;
> + unsigned int offset;
> + int i;
> +
> + /*
> + * Check if the hwirq number is valid, and if so, to which
> + * ODMI frame it belongs
> + */
> + spin_lock(&odmis_lock);
> + for (i = 0; i < odmis_count; i++) {
> + if (d->hwirq >= odmis[i].spi_base &&
> + d->hwirq < (odmis[i].spi_base + NODMIS_PER_FRAME)) {
> + odmi = &odmis[i];
> + offset = d->hwirq - odmis[i].spi_base;
> + break;
> + }
> + }
> + spin_unlock(&odmis_lock);
And that too.
> +
> + if (!odmi) {
> + pr_err("Failed to teardown msi. Invalid hwirq %lu\n", d->hwirq);
> + return;
> + }
> +
> + irq_domain_free_irqs_parent(domain, virq, nr_irqs);
> +
> + /* Actually free the MSI */
> + spin_lock(&odmis_lock);
> + __clear_bit(offset, &odmi->bm);
> + spin_unlock(&odmis_lock);
> +}
> +
> +static const struct irq_domain_ops odmi_domain_ops = {
> + .alloc = odmi_irq_domain_alloc,
> + .free = odmi_irq_domain_free,
> +};
> +
> +static struct irq_chip odmi_msi_irq_chip = {
> + .name = "ODMI",
> +};
> +
> +static struct msi_domain_ops odmi_msi_ops = {
> +};
> +
> +static struct msi_domain_info odmi_msi_domain_info = {
> + .flags = (MSI_FLAG_USE_DEF_DOM_OPS | MSI_FLAG_USE_DEF_CHIP_OPS),
> + .ops = &odmi_msi_ops,
> + .chip = &odmi_msi_irq_chip,
> +};
> +
> +static int __init mvebu_odmi_init(struct device_node *node,
> + struct device_node *parent)
> +{
> + struct irq_domain *inner_domain, *plat_domain;
> + int ret, i;
> +
> + if (of_property_read_u32(node, "marvell,odmi-frames", &odmis_count))
> + return -EINVAL;
> +
> + odmis = kcalloc(odmis_count, sizeof(struct odmi_data), GFP_KERNEL);
> + if (!odmis)
> + return -ENOMEM;
> +
> + for (i = 0; i < odmis_count; i++) {
> + struct odmi_data *odmi = &odmis[i];
> +
> + ret = of_address_to_resource(node, i, &odmi->res);
> + if (ret)
> + goto err_unmap;
> +
> + odmi->base = of_io_request_and_map(node, i, "odmi");
> + if (IS_ERR(odmi->base)) {
> + ret = PTR_ERR(odmi->base);
> + goto err_unmap;
> + }
> +
> + if (of_property_read_u32_index(node, "marvell,spi-base",
> + i, &odmi->spi_base)) {
> + ret = -EINVAL;
> + goto err_unmap;
> + }
> + }
> +
> + inner_domain = irq_domain_create_linear(of_node_to_fwnode(node),
> + odmis_count * NODMIS_PER_FRAME,
> + &odmi_domain_ops, NULL);
> + if (!inner_domain) {
> + ret = -ENOMEM;
> + goto err_unmap;
> + }
> +
> + inner_domain->parent = irq_find_host(parent);
> +
> + plat_domain = platform_msi_create_irq_domain(of_node_to_fwnode(node),
> + &odmi_msi_domain_info,
> + inner_domain);
> + if (!plat_domain) {
> + ret = -ENOMEM;
> + goto err_remove_inner;
> + }
> +
> + return 0;
> +
> +err_remove_inner:
> + irq_domain_remove(inner_domain);
> +err_unmap:
> + for (i = 0; i < odmis_count; i++) {
> + struct odmi_data *odmi = &odmis[i];
> +
> + if (odmi->base && !IS_ERR(odmi->base))
> + iounmap(odmis[i].base);
> + }
> + kfree(odmis);
> + return ret;
> +}
> +
> +IRQCHIP_DECLARE(mvebu_odmi, "marvell,odmi-controller", mvebu_odmi_init);
>
It otherwise looks pretty good to me.
Thanks,
M.
--
Jazz is not dead. It just smells funny...
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